Caged Wisdom

Hybrid systems and mathematical oddities

2012-01-30T11:00:00.001-06:00

While I was hoping to upload this post by the weekend, one thing (laziness) led to another (watching copious amounts of Battlestar) and my to-do list persists! So it goes. With a new semester upon us, I figure I should give just a hint of the fascinating mathematics that I’ve been delving into the past couple of weeks. Some of the most fascinating bits of hybrid control theory that I’ve been exposed to thus far have been illustrated with seemingly trivial problems. (Hybrid control, in a nutshell, is the control of continuous system which encounter discrete switched states. Hopefully this is clarified with the bouncing ball example). However, the results of the analysis prove to be profound. One simple example, a bouncing ball, illustrates how naïve modeling results in physically impossible implications. In this case, Zeno behavior.

Zeno behavior arises in low fidelity hybrid system models in which the state trajectory gets “stuck” in a switched area in finite time. (This behavior is aptly named after the paradox suggested by the Greek philosopher, Zeno. He conjectured that one was to step halfway to a wall, then half way again, and so on ad infinitum… you would never actually reach the wall… well, his true example involved Achilles and a tortoise). In the bouncing ball example, with a simple model of the ball that attenuates velocity each bounce we encounter a point where the ball bounces an infinitely many times in a limited time. Physically, we know that this is impossible. However, if we’re not careful with our models, Zeno behavior can crop up and destroy both control design efforts and simulation ability.

My top 2011 albums

2012-01-23T16:04:00.001-06:00

I know this discussion might seem out of place now with the new year nearly twenty days behind us now, but none the less, I’ve been wanting to mention my album choices of 2011. Thus far today has been heavily devoted to the daily standard grind, so I figured I would spend a little time mentioning music that has really helped to shape how I view 2011. The way I figure I’ll do this is mention the top five albums that I listened to this past year and then go into more detail about my favorite two (man did I listen to these albums relentlessly…

And now, introducing the albums… in some particular order, beginning with my absolute favorite and moving to a more amorphous collection of albums that were constantly playing at work:

What I love to find in music that I listen to on a regular basis is depth beyond a melody and a harmony. The Yeasayer’s album, Odd Blood, has intensely deep track layers that I find myself discovering a new sub-sub-sub melody after twenty listens. Of course, complexity alone isn’t what creates spectacular music, Yeasayer also manages to interlace all these melodies/harmonies/craziness into something almost pop-y. The upbeat melodies keep my focused intently on work, and the depth of the music keeps me coming back for more!

The other album that I’ve consumed voraciously this past year is Beirut’s latest album, The Rip Tide. In a way, I want to claim similarities between it and the Yeasayer’s album… but that would be a trivial oversimplification. Beirut’s style lies completely in the folk domain, whereas Yeasayer’s could be considered something like psychedelic electronica. Again though, the depth of the melodies is what draws me to The Rip Tide. It is shocking what can be done with just vocals, horns, and the occasional synth.

Willpower boost with self-tracking awareness?

2012-01-13T11:34:00.003-06:00

I remember when I first read about this Nicholas Felton character thinking he lost a couple of screws up top or something. Essentially each year, he distills his life down to a condensed annual report with various statistics about his year. Shear lunacy, I thought. More recently though, I’ve begun to experience the shear boost of willpower from knowledge of personal tracking. Whereas before I was only accountable to myself and my advisor (graduate school and all), I now feel like I hold accountability to anyone that follows any of my statistics.

Having not paid much attention to my personal tracking mechanisms till late, I didn’t realize the shear number of data that I already have on my life. More recently, I’ve started tracking (in detail) my exercise and sleep… all to my substantial benefit. In a sense, my Last.fm account was my first major foray into self-tracking, but my discover of Gmail year in review allowed even my ancient gmail account to become a massive source of personal information. My other older tracking account of course is my Good reads account with which I track all books that I read in a year.

Lately though, my obsession has been ratcheted up a notch with my discovery of endomondo and an android sleep tracker app. The past week or so, I've been tracking every single one of my workout with endomondo. This has proved to be of massive benefit for me personally. Before, my jogs were often short or my pace would slow down considerably as I ran. With this app, I feel constantly encouraged to push myself further and further. I should soon be breaking eight minute miles if I keep up my pace improvement! The sleep tracker on the other hand really aids with my knowledge of exactly how much sleep I’m getting. When I wake up in the morning, the last thing on my mind usually is to figure out how many hours I slept. To my surprise, I’m sleeping considerably less than I thought, so I’ve made it a prerogative to sleep at least seven hours a night. Willpower enhancement? Seems like I found something that works for me!

Guitar effects build!

2012-01-07T17:11:00.000-06:00

Summing up the past week in just a single word is actually nearly a triviality… soldering! I spent the better part of last week constructing and attaching current sensors to our robot in the lab, but on top of this mandatory soldering madness I built a BYOC! For those unacquainted with BYOCs ( a quick google search would most likely ameliorate your knowledge, videos included!), you essentially build your own clone (hence the BYOC acronym) of guitar pedal effects. Stephanie surprised me for Christmas this year with one the most intricate (and downright epic!) pedals, the Digital echo/ping pong! I spend the better half of Friday soldering the thing together, and took a few pictures to document the effort… I figured I should share them with my readers (all one of you!).

As any component heavy project should being, I ran through the parts and checked stock. The picture above shows all the components that actually go into this digital echo pedal… not trivial at all! Really though, at the heart of the electronics are two ping pong chips and an op amp… the rest of the pieces seem like voltage regulation and signal conditioning components (though I could be wrong, I haven’t inspected the schematic in detail).

This next picture shows the shear (no pun intended) amount of circuitry here! Look at the size of that excess component wiring pile there, and this was only halfway through the build.

After finishing the PCB, I had to construct and wire the pedal enclosure. The picture above shows the complete soldering of the PCB and pedal… but sadly I couldn’t finish everything! Even though the component list checked out with my stock, I was still missing a film capacitor (seems like there was a typo in the bill of materials…). I’m hopeful to hear back from the BYOC customer service to finish my pedal and start testing! I’ll update as soon as I can!.

On Model Predictive Control (My recent quest)

2011-12-30T18:22:00.002-06:00

Well, winter break hardly began and it is already coming to a close. I’ll have to write a more journal-like post to document the trip up to Snoeshoe, WV, but today I want to discuss one technique of control theory that I recently came to know and love. Model Predictive Control (MPC) has always fascinated me and been something of an enigma to me since I knew little about it. However, the more I read about the subject matter, the more I wanted to share some of my findings with the interwebs. I’ll go over the basics of the theory and then I’ll wrap up with a little example that I coded in Matlab yesterday.

MPC is, in a nutshell, an practical implementation of numerical optimal control. All good control graduate students are exposed to optimal control at one point or another, but usually to the analytic (archaic at this point) calculus of variations (COV) version. In the COV incarnation, optimal control is difficult and adding constraints (limits and room boundaries), makes analytic computations nearly impossible. Numerical implementations of optimal control can solve this however.

I should mention, before I delve to deep into the theory, that optimal control at its core is a open loop control strategy… we find the optimal controller values and then run the system. If our system is not perfect or we hit a wall, optimal control is now confused and more or less screwed! So we run into the classic justification of closed loop control… where we watch what is going on and change accordingly. This, of course, is where MPC comes in the picture. With MPC, we implement optimal control at ever time step ( every second, say) and use only the next step of the resulting control… if something were to happen, we re-optimize accordingly!

In the following example, we have a three state system with state constraints and control constraints. In other words, if we think of this as a robot, the robot has a maximum speed, and is contained in a room. This system attempts to follow a desired path, shown in the figure below. The optimization window for MPC is adjusted and we show that by having an extended window, the path of the MPC controller approaches the optimal path (as given by a purely optimal controller).

Estimating uncertain parameters

2011-12-06T17:37:00.001-06:00

One of the current problems for model-based prediction with uncertain parameters is establishing the uncertainty on the parameters in the first place! There are a few ways, some better than others, to establish some sort of probabilistic bounds on parameters, and I’ll discuss a few here. Before I delve into techniques for estimating the parameters, I should honestly reintroduce a topic that I’ve discussed on this blog in the past. Although the notation is somewhat academic, I believe the concepts of aleatory and epistemic uncertainty do help clarify certain concepts in stochastic/uncertain system. Epistemic uncertainty relates to uncertainty introduced by lack of model fidelity. Imagine a system that operates as a sine wave, but we model it as just a linear curve. At low (absolute) values, the curves look nearly identical, but at higher magnitude values a divergence occurs. In the case of our model, we introduce higher uncertainty than actually exists in the system. Aleatory uncertainty, on the other hand, remains nearly impossible to eliminate. Statistical variations in the environment and setup contribute to the uncertainty in the system.

Now that we have some concepts clarified, I’ll discuss more detailed problems with trying to quantify these said uncertain parameters. If we have an experimental setup in a controlled environment, we can easily run many experiments and statistically quantify the range of values of a parameter. However, if we’re operating a robot in a complex environment, the parameters that we encounter might vary according to time or position. Experimentally determined values would ignore the change in model operation. To update the estimate of the parameter, we can use a real-time state/parameter observer. The Wikipedia article on observers is actually quite excellent, and I recommend it to anyone interested in learning more! Essentially, we can update our estimate for the parameter in real time as the robot traverses terrain. However, this only reveals the instantaneous value of the parameter. For prediction we want to use historical data to more accurately assess a future operational status.

The quick example that I was working on today is a simple mass-spring-damper system with uncertain damping. An extended Luemberger observer estimates the current value of the damping parameter given some uncertainty. Using this estimator, we’re able to estimate the values of the damping coefficient (even if bimodally distributed) as shown in the figure above.

Week links in review

2011-12-03T14:58:00.000-06:00

This week I stumble across quite a few fantastical links… most of which I already shared with the world via twitter. Here are a few things that I think are worthy of a second share or that never quite made it to twitter in the first place.

Political

Illustrated Guide to the Eurozone
Quite a comical (yet heavily biased toward the north) map of the Eurozone. Of course, we’re all aware of the sovereign depth crisis experienced in the south, but the extent of the widespread currency use across such varied nations is really the core of the problem… also why is Finland so creepy??

History

Rise of civilization and beer
I always thought this was more of a fringe theory than this documentary seems to indicate… then again, it is from the Discovery channel.

Art

The whiteboard as a canvas
I always wish I could use my whiteboard for something more than deriving dynamic equations and silly stick figures… this guy put me in my place.

Dragonborn Cover
Since part of my life recently has been spent in the realm of Tamriel, I figure I’d give some sort of shout out to the realm of the dragon-born.

Science

Build your own microbio Lab
I've always wish I could learn more about the biological sciences... just think, I could do some polymerase chain reaction analysis... I'd definitely check the surfaces in our basement lab... there would certainly be never discovered forms of life there... guarenteed!

Conspicuous lack of posts

2011-11-30T11:09:00.001-06:00

I figured I should update the blogosphere with some kind of acknowledgment since my blogging regularity recently plummeted. It has nothing to do with my health, in fact, I’m feeling my best in years (headaches are under control now it finally seems!). In reality my lack of posts has more to do with a perfect storm of laziness that swelled upon me. Hopefully in the next couple of weeks, I can crack some of these habits and get back on track with my writing.

Everything began about a month ago, when I started to record fewer and fewer daily journal entrees. Rather than spending my time on something productive instead, I would often just watch shows or drown endless hours into the internet. If something productive came from these wasted hours, I can show nothing of it. Research has become more and more time consuming, and a couple of recent hitches have caused me much anguish and sapped countless hours. Hopefully before this semester ends, most of these issues can be resolved…. I want to have a draft of the journal paper ready before the new year begins! This will pave the way for a painless PhD proposal presentation (hopefully).

Gaming has increasingly become a negative distraction in my life recently as well. With the release of Skyrim and a new found addiction to League of Legends, I find many hours in the evening eviscerated. One of the ways out of this lazy slump is to ramp down the game time and limit myself to perhaps an hour a night. So as you can plainly see, a whole slew of things serve to distract me and keep me from writing regularly. Hopefully like my last public declaration on this blog, I will reinvigorate my post writing and I’ll actually maintain some regularity again! I hope to write again soon!

Future brewing plans

2011-10-05T19:06:00.002-05:00

One of the more interesting hobbies that I picked up during my college years (there are a whole spectrum since I’m a chronic dabbler, and I’ve decided to slowly reveal a few at a time… something productive must come out of all that time spent reading random Wikipedia articles about chess openings!) is the art of brewing. I wouldn’t go as far to call myself a master brewer yet, but perhaps I can bestow the title of journeyman on myself. I’ve made several batches, with and without the help of friends, and all of what I’ve made thus far has turned out to be quite delectable! Since another one of my dilettante activities is the copious consumption of historical texts, I decided for my last brew to follow a recipe for a 1940’s style American IPA. The history of the IPA in general is quite fascinating, and the Wikipedia article (bear with me here!) does a fantastic job covering its inception. Anyhow, I digress…

Since my last brew was historical, I want to follow along that trend and perhaps experiment a bit more with the recipe. My last batches have more or less followed the recipes provided by Austin Homebrew, which have been so nice, that I’m weary of deviating from the literal instructions… but perhaps it is time! The next batch I’m planning on cooking up is a Wee Heavy style beer which at one point was my favorite style… and I anticipate this style will overtake the IPA in a year or two as the most popular beer amongst the snobs out there. Anyways, the Wee Heavy style is a prototypical Scottish beer with lots of malt plus a high hop level, essentially heaven in a bottle! If I get around to brewing in the next couple of weeks, I’ll post progress photos of the process (and perhaps some brief blurbs on what is actually going on)!

Approximating reality - Gaussian mixture modeling

2011-10-03T12:02:00.000-05:00

One of the hidden beauties of the field of statistics is the central limit theorem. When data from various different distributions is combined (summing, or averaging) the resulting distribution approaches the normal distribution. This is one of those near magical aspects of statistics when you first are introduced to the topic. However, with some thought and practice the concept becomes clear. (To help elucidate the concept, check out this java applet with various distribution sampling). As a contrast to the inherent trend to the normal distribution, if a sampling comes from entirely different sets of distributions of data, we end up with an overall nonlinear distribution which is difficult to deal with.

For instance (imagine the world is a line segment for ease of visualization) picture a robot traveling along a line with two sensors detecting the position of the robot. If these sensors are corrupted with normally distributed noise, then we cannot be certain where the robot is precisely. We just have a probabilistic notional sense of where we are. If we didn’t have a clue which sensor the data was arriving from, then we’d have a smear of data across the x-axis. The data would be clustered where each sensor thought the robot was, but viewing the data as a whole, we would just see lots of points. Ok, now where am I going with this? What if we want to determine which sensor contained which data found… we have to separate out the data points and find the individual distributions which resulted in the overall data stream generated.

One potential method of analysis of this data is the Gaussian mixture model. In a nutshell the mixture model technique determines which sets each of the data points is most likely to belong too and creates individual normal distributions (any distribution could be chosen though) to represent the data. Technically, the Gaussian mixture modeling algorithm relies on expectation maximization which places each data point with other that have the maximum expectation for a certain set. You can read more about this on Wikipedia or in this paper. Just to give you all a visual of the capabilities of the Gaussian mixture modeling technique, I created a basic simulation with three mixtures that are clustered out.

Weeks links in review

2011-09-26T23:55:00.002-05:00

Another new week is upon us, and this week I’ll be flying to Florida for an electric ship workshop. Anyhow, here are some links for you to peruse while I’m gone.
Science:

Faster than a speeding photon

Everyone and their brother on the blogosphere has been up in arms about the reported faster than light neutrinos. I’m opting to remain on the conservative side here… to much uncertainty remains for such a claim.

UARS falls to Earth

The UARS finally came down this week. People have been tracking the satellite for weeks now with anticipation of something interesting happening… it just fell into the Pacific!

Political:

Troy Davis executed

The Troy Davis execution went ahead without a stay from the Supreme court. I have to say that I wasn’t surprised since they had denied one earlier this year. However, the evidence against Davis was dubious at best making this whole ordeal very troubling.

Interesting:

Wing suit through cave

Incredible footage of a wing suit flight though a rock gateway formation in China… just unfathomable!

OMG puppy break!

If you need to view something cute… click here! Puppies!

Charity balloon release gone wrong!

Next time make sure you check the surrounding area for sharp pointy sticks… a charity balloon release gone wrong.

Breaking Bad - My Thoughts

2011-09-26T19:46:00.001-05:00

I’ve never significantly devoted much attention to regular tv viewing until fairly recently. Breaking Bad remains one of the only shows which has captivated me and kept me glued to the screen. The plot seizes me at a level that no television has ever managed to do before, and I often finish an episode with a hodgepodge of confused emotions. (This is coming from someone with a fairly detached personality) I just recently finished season three, and I’m still reeling from the plot arch… from what I’ve heard, season four continues this emotional rollercoaster.

Not only is the plot of the show (trying not to reveal any spoilers…) riveting, the acting and character development are phenomenal. Each of the characters has been developed to a point to where, as the viewer, we feel very connected to each of them. Their pains become ours, joy flows from the screen into the viewer. All of this would not be possible without the incredible abilities of Bryan Cranston and Aaron Paul (the leads) amongst others! Needless to say, if you haven’t already checked out Breaking Bad, you really should! Even if you’re not a fan of television! (If you’re already a fan… this post probably comes off as a the ramblings of a fellow fanboy!)

Interesting reads of the week:

2011-09-19T12:13:00.001-05:00

Since I’ve become a more active poster on my blog, I figured I should also actively give props out to some of the things I’ve been reading this week. If I have a chance, I’ll keep posting link updates each week of stories, editorials and videos which shape my opinions reflected in my other posts.

Science stories:

First confirmed observation of a “circumbinary planet”

Of course, all the media outlits were abuzz about the discovery of a planet orbiting a binary system. Everyone instantly jumps to the conclusion that we’ve found Tatooine, since hypothetically one could recreate the scenes from Star Wars.

Neutron star surface simulation

Given the recent supernova eruption in M101, I figured that a nod to simulation based analysis (much akin to what I do) of neutron star explosion.

Dr. Oz and idiotic analysis

Apparently several schools are beginning to pull apple juice from their cafeterias due to a “study” conducted by Dr. Oz which revealed the juice to have abnormally high levels of arsenic. What he didn’t investigate however, was what type of arsenic is actually poisonous to humans… inorganic counts of arsenic are evaluated for potential poisonings… not total arsenic.

Politics:

More on Michele

My god, will this never cease? Bachmann has again utterly blown my mind with stupidity on vaccines… not to mention the other slew of opinions she has.

Special elections to the Republicans

I know there is a potent anti-incumbent sensation in the country currently, but you would think that people would see the current state in Washington and take that attitude to the polls with them. Both parties are hated, especially the Republican congressional leaders… but somehow they pull ahead.

Interesting:

Stephen Wiltshire: The Human Camera

A nice little documentary about Stephen, who has a photographic memory and the ability to draw.

Ojai Valley Taxidermy

Speaks for itself!

Poster Blitz

2011-09-16T15:33:00.002-05:00

Last week I found out that I would be traveling to Florida at the end of the month for a conference. I also was informed that in addition to my attendance to the confenrence/workshop, I would have to present a poster. Nominally, construction of a poster takes about a day or two, so initially I wasn’t too worried. However, I soon found out that rather than a purely technical poster, the information would need to tend towards generality. The primary audience of the conference will be industry and political, so I had to take existing presentations and translate them into “simple English” (check Wikipedia translation choice – simple English!)

Of course the whole reason that I’m writing this post is to elucidate the point that explanation to laymen is deceivingly difficult. With the knowledge I have, it takes arduous effort to retrace my learning steps from the inception of the subject. And to make matters more difficult, not everyone learns with the same style or at the same rate. Since nearly every major university has a department of education where people learn to teach effectively, overcoming the curse of knowledge is anything but trivial.

Essentially my method for explanation of tedious topics of estimations and power systems was to illustrate them graphically if possible. I’ve also minimized text, though honestly I could remove more, and I incorporated many arrows to aid with concept flow. I’ve got some colleagues aiding the inspection of the poster, so hopefully the gist of my research comes across clearly!

The Covetous Class

2011-09-15T20:27:00.000-05:00

The recent outcry at the IPO of Groupon and the all-around discontent in the United States helped me to come to the realizations I will put forth in this post. I’m certain that what I say will not sit well with some, primarily because I attacked some basic premises of what it is to be an American… but I do believe that what I’m claiming tends toward truth. The basic idea boils down to this: all people are covetous, but the middle class tends to exemplify this. The rich, knowing of this fact, pit the middle class against itself to create political turmoil which upsets elections and sways opinion to whom the wealthy desire.

The evidence of this so called covetous class is fairly self-evident. Take my recent example of the Groupon IPO. Why is Groupon so overvalued?? Well, this overvalue stems from the American moral of the “good deal.” People love to save money whenever possible, which in its own right is an aspirational goal. However, the problem with a system like Groupon is that the noble goal of making a wise purchase for a good price becomes a witch-hunt for the lowest price, no exceptions. Deal seeking has become an epidemic especially given the dire state of the economy. Little to no care is given to the vendor, all that is important is the final price tag. Common human decency has failed yet again.

Now why though did I attack the middle class? Well, the premier deal-whores reside deep in the heart of the… you guessed it, the middle class. (Keep in mind that I’m attacking myself here, as well). Essentially since politicians are blissfully aware of the state of the middle class is, they are fully capable of exploiting it. Rather than a sense of unity, the middle class treats others in its ranks as alien… the group is fragmented. How can we plan to ever unit against the tyrants of society if we’re not even capable of treating one another with a since of common decency!

Marking a decade

2011-09-11T18:10:00.002-05:00

“The morning was bright and crisp..” or so begins much of the coverage of the events of September 11th. The temperatures for me, on the other hand, were already climbing into the upper 90’s with a chance to breach the centennial temperature mark. Bullets of sweat poured down my face as we marched our final practice set and began to walk back towards the high school. Marching band, to much of our chagrin, continued to be held from 6:15 am till 7:30am, right before school would begin. Sadly, our other option was to bare the scorching sun in the afternoon when temperatures were regularly over 100… many of us were willing to sacrifice for another hour of sleep in the morning. Since I was in the top band, we actually rehearsed immediately after marching band during the first period of school. As such, we were relaxed and chatted like any other day before school… until one of our band directors darted out from his office and turned on the television in the band hall. One of the towers had already been struck… soon after taking in the initial shock of what I saw, the other tower was struck.

None of us in that room could fully comprehend the magnitude of the event that now plays out in my head like an old friend. We were blissfully unaware of the scope of what was to come. After about 15 minutes of watching the flames erupt from the upper floors, someone suggested we form a prayer ring. Even at this point in high school, I was beginning to drift away from religion, but I felt a strong urge to join in… to replace the vortex of confusion and void that occupied my thoughts. Everyone went around the ring making a remark or thought for the crash victims and for the safety of those affected. What occurred next, I will never forget. After the ring disbanded, we all looked up to the television again, and before our eyes the south tower began to collapse. When I first witnessed this event, my mind only could interpret it as the upper most portion of the tower collapsing. Only after the smoke cleared did I realize that the tower had actually collapsed entirely… innocence had come to an end.

Hidden costs of libertarianism

2011-09-09T14:08:00.002-05:00

I know I’ve discussed similar topics before on this blog (see here and here), but seeing the current political discourse (especially some of the fallout due to the president’s job bill address) I figured I should post my current thoughts yet again. Also before I get started, I want the readers that are unfamiliar with my viewpoints to understand where I come from politically. In my late teens and early twenties, one could classify me as a staunch libertarian. I felt deeply (especially after reading all the classic libertarian texts: Austrian school works, Ayn Rand, and Goldwater) that each individual was deeply, at their core, responsible for his/her own destiny and thus should be independent from any political/governmental regulations. Of course, I quickly realized to make this system more practical (physically implementable), a limited form of government was necessary to preserve individual rights, and prevent others from oppressing them.

So my world view during my post-angst years was spent believing that the world could operate in a politically Sartre-ian way. All individuals have free reign over their destinies, and as such since oppression is the root of evil, society as a whole will transcend itself… of course, as a result, utopia. Government would be minimal, people could do as they pleased as they are personally responsible for their own actions. However, after a year or so of this thought, I made some stern realizations… people are… well human. As such, infallibility reigns, and a system, such as the one that I described, which relies on mutual respect of individual liberties, crumbles immediately. I reached a state of dilemma, unsure of a perfect system for governments. One striking realization that truly rattled the foundation of my psych is healthcare in general, and the idea of insurance.

For health insurance to make sense (and to be financially feasible without subsidies from the government), people must be required to enroll in insurance immediately after birth. Now why is this? The idea is to implement some source of certainty into the healthcare system. Rather than having people to elect into the system when they are already sick or visiting a hospital uninsured, insurance companies will know what their current assets and have a good rough estimate of the outgoing liabilities (a classic accounting problem). Not however, the system is so convoluted and bureaucratic, that the only solution is to raise rates! Not to mention that insurance encouraged people to opt for expensive treatments, rather than continuously practice preventative medicine (not profitable)!

Unscented Transformations

2011-09-07T15:40:00.003-05:00

Another method which I’ve been implementing for parameter uncertainty estimation is the unscented transformation (which as one might expect is the basis for the unscented Kalman filter). Since I’ve been recently discussing the inherent ineffectiveness of first order Taylor uncertainty propagation, you all should be well aware of the potential flaws in its predictions. For “hard” nonlinearities with jump discontinuities, we encounter strange linearizations which propagate though the calculations and effect the final answer. One method that I’ve been working on and discussing is another form of linearization (describing functions analysis), but the unscented transformation is an entirely different approach. Rather than linearizing the nonlinearities, we utilize these functions to capture the statistics of sigma points.

The above plot displays the general idea of the unscented transformation. A general function (f(x) = sin(x1) + cos(x2)) is given with the input variables having normal distributions. Since the variables are random variables, the output of this transformation is also going to be a random variable. If we assume that the output of the function will also be normal (a decent assumption in this case for small variance), we can propagate the uncertainty though the function and compute a normal output. The unscented transformation selects statistically significant “sigma points” (shown above as pink dots), and these points are all fed through the function, f(x). The output for each of the sigma points are then analyzed and the statistics for the outputs are computed (mean and variance for a normal distribution). The plots above show how the unscented transformation fairs against other prediction methods (the ellipsoids are centered on the mean of the prediction and the radii indicate the standard deviation prediction). As can be seen, the unscented transformation more readily approximates the actual statistics (as computed by Monte Carlo) and radically outperforms the Taylor first order prediction.

Sensitivity of hard nonlinearities

2011-09-04T16:07:00.002-05:00

As I discussed the other day, I’ve been working on some techniques to help improve the solutions to my energy uncertainty estimates. I’ll go into a little more detail on to why these solutions often produce erroneous results and my next steps to decrease the errors in the predictions. To recap quickly, what I’m working on currently is an online robotic energy estimation system which will calculate the remaining energy on the system given all the uncertainties in the robotic system. So we have load uncertainties (terrain effects on actuators, whether or not a sensor is activated, or the load on the on board computer), parameter uncertainties (each robot is different, no two wheels is alike on an extremely accurate scale), and source uncertainty (when know approximately the remaining charge on the robots battery). Given all the sources of uncertainty, I want to predict (and reconfigure) the system such that we can conserve the battery life to ensure the robot completes its objective.

Unfortunately for me, in a baseline first principles model case, I’ve been running into algorithmic issues due to the large errors contributed by a nonlinearity in the calculation. In an attempt to calculate the energy consumed by an actuator with no regeneration capabilities, the variance estimator requires a linearized form of the absolute value of a bilinearity (or more straitforward, P = |F(t)v(t)|). The Taylor linearization of this function quickly loses accuracy with larger input variances. To prove that, shown above is the error the first order variance estimate with changing input variances. Since the axes are all given in logarithmic units, the error increase with slight increase in variance is drastic. As such, I hopefully will find a drastic reduction in error with describing function analysis… else first order approximations are out altogether. From there I’ll have to opt for more computationally complex algorithms, such as unscented transformations or particle filtering.

Describing nonlinear functions rigorously

2011-08-30T22:17:00.002-05:00

Lately I’ve been working a lot on simulations of uncertainty propagation in nonlinear dynamic systems. As a first principles test case, I was evaluating several of the uncertainty propagation techniques (Monte Carlo, Taylor approximation, unscented transformations, etc.) on a simple mass spring damper test case. The ultimate goal was to evaluate the performance of the mechanism and estimate the energy consumed (both the energy mean and variance, assuming Gaussian distribution…more on that later). However, even though the system itself is linear, bilinearities appear due to the uncertainty associated with multiplicative parameters. The damping coefficient forms a bilinear relationship with the velocity of the system (b*v) and as such we have a nonlinearity in terms of the uncertainty. Another nonlinearity is introduced when you attempt to calculate the mean squared power draw… essentially an absolute value function. This function is a much “harder” nonlinearity when compared to the bilinearity (which can be linearized via Taylor series quite easily).

There are a plethora of techniques for nonlinear analysis, but not all are created equally. Some techniques, such as Taylor linearization, are typically fantastic, but on occasion produce wonky answers. This occurs most often in functions which contain points which are not differentiable (in the case of |x|, x=0). Since we have a system with many zero crossings, we’ll run into the inaccurate approximation twice every period of oscillation. Another way which attempts to describe a nonlinear function more rigorously is describing function theory. Needless to say, I’ve been acquainting myself intimately with this subject matter… so I’ll attempt to explain the basic gist in a paragraph now and I’ll come back in more detail in another post.

To derive a describing function of a given nonlinear element of a system, we essentially either: (i) find another (linear) function which equates the convolution of a linear function and the input with the cross correlation of the input and output, or (ii) minimize the mean squared error of the function and describing function (statistically). While each of these methods is fundamentally derived differently, we can actually combine the two to model deterministic inputs with noise as applied to nonlinear systems. The figure I created above illustrates nicely the concept… my next post on this topic, we’ll discuss the actual application.

Posthumous Vacation Posts

2011-07-30T11:02:00.000-05:00

We those of you that know me personally (as in real life, and not through creeper internet stalking!!) know that I’ve been back in Texas for near a week now. I figured that I should go ahead a brief heads up that I plan on recapping my south west epic journey with Stephanie on the blog over the next couple of weeks (when I get a chance of course, since I’m always busy!). Hopefully by putting this pledge where other can (potentially) witness it, I stay true to the promise! Again though, due to the amount of work that I’ve been swamped with recently, this oath only might be partially filled!

I will give a brief teaser on the road trip, to get potential readers excited about the posts. Overall the journey was phenomenal and I am eternally grateful to all the folks we ran into and encountered which shaped the trip into a fantastic memory that I will cherish and cite when I’m old. There, of course, were ups and downs, as any good journey would have (provides the seems that hold the memory tight in the mind!)… but on the whole, again, the trip was remarkable! Hopefully, this will peak your interest a bit, dear reader, and you’ll stick around to find out more!

Side note:

Since I want to keep my posts in order and, for posterities sake, on the correct date (so that when I look back in the future and read them, I remember the dates correct!), I will be posting from the past. To make it easier to find these posts, I will tag them all as road trip and vacation which should make them more accessible!

Minimizing uncertainty in estimates

2011-07-29T16:56:00.002-05:00

Today I want to address an interesting problem, the estimation of values of a “system” (such as speed of a car, etc.) given measurements. This problem as it is posed is truly a fascinating one for controls engineers, notably since it mirrors the concept of control design. At the cores, designing a controller and an estimator (also known as an observer) are intrinsically related, and many interested problems which arise in control design also curiously reappear when designing an observer. What I want to introduce (albeit quite briefly) today is the concept of the Kalman filter and what exactly one can accomplish by employing one.

Although the namesake of the filter, Kalman, derived the concepts of the filter about fifty years ago, the Kalman filter is still frequently used and studied to this day. One might wonder how such an archaic concept (in terms of today breakneck pace of innovation) remains such a useful tool with applications ranging from the space program (Martian rovers, shuttle, etc.) to the oil industry. The Kalman filter remains important due to the first principles (I’ve used this phrase before. Essentially, what I mean is concepts arising from basic knowledge) derivation. Rather than minimizing the error of the estimate as in the case of least squares estimation, we strive to minimize the Bayesian variance estimation of the estimate. Wow, that is a ton of jargon, so I’ll try to explain the gist of it all! Here we go!

Starting with the word Bayesian… what does that mean? Well, essentially there are two (main) competing views in the world of probability. The frequentest approach and the Bayesian approach. Frequentests look at probability as a field of categorization in a sense. Given a bunch of measurements for a single event, we can categorize the probabilities of that event. However, frequenter argue that these probabilities are only valid for exactly the same circumstances! For example, imagine that we know the daily rain fall measurements for an entire month. We can statistically analyze the data, but we cannot predict using our statistics the chance of rain the following day. Why? Since the day of the week is different, and the weather patterns are different. The only way, according to a frequentest, that we could predict the rainfall the next day, is that if history repeated itself, so to speak, and exactly the same weather patterns occurred. Bayesian, on the other hand, takes a more approximate approach. We can assume that “similar” events have occurred, comparisons can be made. Engineers like to take a Bayesian viewpoint for modeling because we can thus model probabilities!

Moving on to the variance… if you’ve taking a statistics course, this term should come flooding back. Variance is just the magnitude square of the standard deviation. Essentially the variance is a way of measuring how uncertain we are of a value. An estimate with a high variance is highly uncertain, while a low variance estimate is more precise. Putting the concepts together… we want to minimize the Bayesian variance estimation. For each estimate the observer gives, we attempt to minimize the variance of the estimation such that the answer is as precise as possible! Of course, as in any detailed subject matter, I’ve shaved off a good number of details… but I’d be glad to explain more at a future date!

Day Fourteen: Caving and return to normalcy

2011-07-22T21:16:00.000-05:00

The final day of our vacation... it is hard to believe that we’ve driven so far and experienced so much! The experience took us from central Texas cross the desert southwest and into southern California… and then back again. We met some fantastic people and caught up with old friends, and overall, this is a vacation that I will recall for the rest of my life. Stephanie and I, turns out, make even better travel partners that I ever imagined! Further proof of our perfection for one another! I guess I should stop raving about the trip and actually discuss the final day (albeit most of it was spent driving through gargantuan Texas).

Other than driving, we did visit Carlsbad Caverns in the morning, which is another one of those places that I’ve always dreamt of traveling too. I remember during my childhood that I envied many friends who traveled there at one point or another when I was growing up. Stephanie had been to the caverns before, but it had been so long (and she was quite young at the time) so the caves were a novel experience for her too! We opted for cave access through the natural entrance… but nearly turned back due to all the warning signs. With all the warnings we found in the Grand Canyon, we really didn’t want to take any chances, but it turned out that the signs were to warn non-physically fit folks from venturing down the natural abyss. While the decent did take a toll on the knees, it was nothing compared to what we encountered in the Grand canyon! On top of that, the natural entrance contained some fascinating structures and cave ins which were not to be seen in the Grand gallery proper.

The cave proper was also incredible and beautiful. We both found the sheer size and number of intricate geological formations fascinating. All the other karst caverns that I’ve been to in Texas are dwarfed in comparison to Carlsbad, and we were just in the tourist/well known areas… phenomenal! And to even begin to think of the epic lengths required to form some of the speleothems especially the columns! After begin put in our geological time place, we embarked on the journey back into Texas and arrived quite late in the evening. All good things must come to an end, and here we are back in the comforts of home.

Day Thirteen: Land of UFOs

2011-07-21T21:10:00.001-05:00

The land of Breaking Bad (Albuquerque) seemed quite pleasant, but we needed to get back onto the road to make the final journey through a state other than Texas. Our path though New Mexico today took up though Roswell on the way to Carlsbad where we’d visit our final destination of interest. Since we made the call not to attempt to make the final entrance time for the caverns, we had ample extra time and decided to spend some of it in Roswell. The city itself is quaint and pleasant, but we were more apt to visit one of the UFO museums and see what other things we could find in town. Turns out, the best part of Roswell was the winery that we found downtown! We did our second New Mexico wine tasting event, and I have to admit that I’m a fan! The museums devoted to the Roswell incident are interesting, but certainty only worth visiting once while passing though… far from a paranormal mecca as one might expect.

The remaining drive from Roswell to Carlsbad took us through some desolate areas. The terrain went from somewhat rugged to pure plains for quite some time. We started to see oil derricks every once and awhile, and we knew that we were closing in on the West Texas border. By the late afternoon, we had made it into Carlsbad, but we were quite famished. A quick yelp search revealed that Carlsbad had a limited selection of foodstuffs (primarily on the fast food end of the spectrum). There was, however, one exception to this, the Trinity restaurant. After so much driving, I’m always craving a fantastically prepared meal, and we definitely found that here!

Day Twelve: Native land of Beauty

2011-07-20T23:01:00.001-05:00

Although the temperature was considerably higher than our camping experience in California, we were both so exhausted that the night’s rest was incredible. We both felt rejuvenated and ready to experience more canyons! The Canyon de Chelly was jaw dropping and one of the most incredible sights that I’ve ever witnessed. The further we drove into the canyon away from Chinle, the more spectacular and steep the canyon became. About half way down the south canyon road, we were able to hike down in the canyon to see some Puebloan ruins (aptly named the white house, also this was the only place where anyone not Navajo could venture down). Oddly enough the hike into the Grand Canyon was actually cooler than the hike into de Chelly. Today, we were subjected to the intense desert sun. At the base of the canyon, we also encountered vendors with some really fascinating handmade products. Stephanie bought a double dream catcher!

The other site, one that I will never forget, was the sacred Spider rock. A towering behemoth of a stone jutting from the canyon floor… just incredible. The rock was actually over a thousand feet tall with no supporting stone from the canyon wall itself. While we were entranced with the views, we met a Navajo couple who explained the meaning and sacredness of the stone. If we had more time to spend in the area, they also informed us of many of the other sites and views nearby. Apparently there are some plateaus further to the east which look like a native American chief and a woman (pareidolia). After our final canyon adventure, we departed for the four corners and fulfilled a little bit of touristness!

Day eleven: Painted landscapes and craters

2011-07-19T23:22:00.001-05:00

We were definitely still sore from the hike yesterday, even with the extra rest and sleep. Unfortunately, we still had to get back on the road since we planned on visiting the Barringer crater, the Petrified wood national park, and the Painted desert before making our way over to camp near Canyon de Chelly. Since we spent the majority of the journey on I-40, the drive to each of these locations passed quickly, and by the late morning we had made it to the meteor crater. The crater was one of those spots that I always wanted to visit since childhood, and our visit did not disappoint! On top of the impressive sight of the crater itself, there was a neat little museum and a fantastic tour guide… we were both glad we stopped.

Further down I-40 we toured the Petrified Wood national park. The night before, I had read that the amount of petrified wood has been decreasing and so we were both honestly expecting a dearth of stone… but to both our surprise, there were stones abound! I can’t even imagine what the park looked like in the past with so much more petrified wood. Because of the tendency for people to steal the stones, they actually had a station which supposedly would check the contents of the vehicle… though we didn’t get stopped. Joined with the Petrified Wood national park was the Painted desert, which was also beautiful. But since the sun was getting low in the sky, and because we had quite a drive to our campsite outside of Canyon de Chelly, we had to get back onto the road. The drive north from I-40 took us deep into Navajo land and before we knew it, we had pitched our tent and were set for another canyon.

Day ten: The real deal

2011-07-18T22:47:00.002-05:00

After the embarrassment of yesterday, we were looking to really capture the essence and the beauty of the Grand Canyon in its entirety. I’ve had the fortune to have visited the canyon more than once in the past due to the nearby proximity of family relatives. Out of all the visitations though, I never had the opportunity to travel into the canyon… even more than a step… and as such I had always wanted to venture forth into the belly of the beast. Although the two of us initially wanted to travel to the base of the canyon and camp the night, we did not apply for a back country permit or a ranch stay (which by the way are difficult to come by) and decided to only hike down about half way. Rather than the more straightforward Bright Angel trail, we opted for the more rugged South Kaibab trail.

The initial descent into the canyon was surprisingly steep. The trail contained ample hairpin curves and at points seemed to have grades as much as fifteen degrees. Once we hiked down about half a mile, the trail started to level out a bit more, and our knees started to take less of a beating. Normally as you descend into the canyon, the temperature begins to climb rapidly (as high as 120 degree at the base). Fortunately for us, rather than having to deal with the scorching sun deep in the canyon, we avoided the extreme heat due to the wondrous overcast. After several hours of hiking, we reached our desired destination, Skeleton Point. Although we felt as if we could travel further… the return trip was all up hill and quite daunting… so we turned back.

On the way down, we always would greet those already on the return journey, and they would nearly always be out of breath. Once we begin hiking upwards, we quickly realized why. Although the hike down was rough on the knees, the return was arduous on both the heart and the lungs. The air became noticeably thinner near the ridge of the canyon. The celebration began once we crested the ridge and placed our feet on level ground again. To celebrate our feat we each treated ourselves to something from the gift shop… I got a vintage style poster of the national park and Stephanie got herself a book on deaths in the canyon. I will admit that I’m looking forward to reading the book as well though!

Day nine: Nadir

2011-07-17T01:10:00.004-05:00

All vacations have to have point of minimum excitement. A few events today has set the bar absurdity and disgust, sadly overshadowing the other fantastic happenings of the day. Let me begin with the good, seeing as sequentially, the day began quite well. After a night of fun in Vegas, we got up and had breakfast before embarking on the journey back into Arizona. Our route was to take us across the Hoover dam and towards the Grand Canyon. Both of us had always wanted to visit the Hoover dam, seeing as it is one of the iconic monuments of America. Everything we encountered at the dam was fascinating, ranging from the museum on the construction, to the actual dam itself! We were both entirely fascinated by the construction process and the people that gave up their lives for such a monument of engineering.

After crossing over into Arizona, we embarked towards a goal that we thought would be another great addition to our trip, the Grand Canyon Skywalk. Turns out that after missing the turn off, driving for miles on dirt roads, and paying a small fortune, I feel as if we wasted part of our existence. The whole experience was a shame. The roads were incomplete for miles with miniscule speed limits. Once we actually arrived, we felt as if there were constant hints from employees to turn back… get out of there! But alas, we persisted and paid the massive lumped sum to walk on a slate of glass, nowhere near the actual historical Grand Canyon. All in all, a horrific incinerator of tourist money…

Day eight: Departing the west and LV

2011-07-16T23:19:00.002-05:00

Bright and early, we thanked our friends for being such gracious hosts and for all that we got to experience with them, and then we quickly got onto the road. Since it was already past ten in the morning and we were going against the traffic, everything was smooth sailing. Once we made it out of the heart of the city, we stopped for lunch at a Wendys before finishing the journey to Las Vegas. Thankfully, this stretch of road was well developed and not terribly long. We were in Las Vegas before dinner time!

Getting to Vegas before dinner was key for us, as we wanted to try one of the many legendary buffets in town. After much review perusing, we decided that the Bellagio buffet was the place to be. Unfortunately for us, since dinner time was fast approaching, there was already a significant line waiting for us by the time we walked there from our hotel. To no avail, we waited around an hour and then embarked on a feast pilgrimage. Although we were impressed with the quantity of food, the quality was severely lacking… we both agreed on this point. My god, the beef wellington was atrocious… anyhow, there were some redeeming factors: the fish, the desserts and the crab… but honestly not worth the money.

After dinner, we walked the strip and stopped by the MGM for a little gambling. Working our way up in the slot machine world (notably video poker and black jack), we ultimately stopped at a $10 black jack table and eventually walked away with $40! The under $10 loss on slots was recovered with interest! Plus plenty of free drinks! Neither of us thought we would have this much fun here, but I think we might make our way back eventually.

Day seven: Art and more

2011-07-15T23:16:00.002-05:00

After all our driving adventures, we craved a location which we could explore without a car. Our friends informed us of the metro system in LA and the gold line which ran from Pasedena to the downtown area. Along this line, our friends let us know, was the Little Tokyo stop which contained a little treasure trove of activities. In a one mile radius, there was of course Little Tokyo, the Museum of Contemporary Art (MOCA), the Disney Concert Hall by Frank Gehry, and some fantastic restaurants.

After a surprisingly quick trip from Pasadena to the downtown area, we departed from the train station and headed across the street to MOCA. The museum was deeply fascinating with street art ranging from its inception in war graffiti to the modern works of Banksy and Shepard Fairly. Stephanie and I spent many hours here perusing the works and admiring the commissioned works specifically made for the museum! So amazing! On top of everything, the museum was the correct size, not too big, not too small, and as such we felt like we got our money’s worth, but didn’t feel tired by the end.

After spending our time in the museum, we were about ready for lunch. Our friends had informed us about a brewery (Angel City Brewery) nearby, but unfortunately it was closed for lunch today. The other suggested place, Wurstküche, was open and turned out to be phenomenal! As one might expect, the main dish would be sausage, and a plethora of sausage at that! I ended up having a rattlesnake and rabbit sausage and Stephanie went for an alligator Andouille Wow, just wow! What a great lunch!

Once we finished our delicious lunch, we departed for Little Tokyo. The area was surprisingly tiny and was filled with little souvenir shops and a few restaurants. Very much a tourist trap of sorts. After walking through the entire area, we walked through downtown to see the Disney Concert Hall since both of us are interested in architecture. Frank Gehry up close is interesting, to say the least…

Returning back to Pasedena, we decided that we should make it to a showing of the latest Harry Potter film. Since we are in LA however, we decided to make our way back to Grauman’s to view the movie in the historic Hollywood theater. Before departing for the theater, we stopped by Green Street Tavern for dinner. We went in knowing the meal should be good, but we left with the best meal of the trip thus far. Quick note about a site we saw on the way to the theater… we saw Kingston Café from Kitchen Nightmares! Once we arrived, we found the theater even more impressive during a film! The crowd was animated, and I felt like the money spent versus a DVD rental was exponentially better spent! What a fantastic way to end our stay in Los Angeles.

Day six: Studios and sightseeing

2011-07-14T23:13:00.001-05:00

One of the primary goals of this road trip for Stephanie was to experience the studios of Hollywood in some fashion. Accordingly, with some research, we decided the best studio to tour would the Warner Brothers. We fortunately lucked out when we arrived at the studio. Since we didn’t reserve a studio tour time, we feared a long wait time when we saw the hordes of people mulling around. However, when we bought our tickets, we were able to squeeze in the immediately next tour time! The tour was entertaining and informative. We saw lots of original props and costumes from movies and also many of the studios where television and movies are filmed.

After the studio tour, we traversed the Hollywood hills and made our way over to the Hollywood area. I had always heard the immediate vicinity around Hollywood was run down, but I was a bit surprised just at how run down it was! Another goal of our was to take a tour of Grauman’s Chinese theater. Eventually after wading through hordes of people, we made our way there and signed up to take a tour. Due to an “interview” and screening inside, our tour took place entirely outdoors… but due to the circumstances, we were able to essentially join another tour group to see the entire theater for the same price. The theater was gorgeous, though a tad gaudy… and of course seeing the handprints in front of the theater was a must!

Since were in the Hollywood area, we impulsively decided to take a brief drive along Muholland drive. Of course, traffic was after us again, and it took what seemed like an eternity just to get there! Once we eventually made our way there, however, the views were pretty phenomenal. We could essentially see the entire San Fernando valley! From up in the hills, we had to make our way back down into LA so that we could visit Korea town. Unfortunately for us, rush hour was upon us… so driving was slow, yet again! Once we made our way down the hills and into town, however, things picked up and we were able to quickly make our way to Mr. Pizza, our primary destination for the evening. Although Stephanie had her reservations over whether or not I would enjoy Mr. Pizza, the food turned out to be fantastic! Both of us enjoyed our pizzas and I almost wish we could’ve had more!

Day five: Day at the beach

2011-07-13T23:09:00.004-05:00

After all of the driving, we really craved some rest and relaxation. Our friends in Pasadena suggested a beach excursion, and we seized on the opportunity after a long nights rest. Just our luck as well, we had an acquaintance in Santa Monica and were able to park for free for the day! We’re lucky to have such awesome friends! Another tidbit worthy of mention, we had Baja Fresh for lunch! I haven’t been there since the place closed down in Austin five years ago or so. It was momentous event for me, and the food was better than I remembered.

Typically, I’m not a beach kind of guy, but after so much traveling the relaxation was fantastic. And the swimming! Swimming in the ocean is one of the activities that I do desire every now and then. As I knew, the water was more frigid than expected but I was quickly able to acclimate to the temperatures. Throughout the day, I ended up swimming for three thirty minute sessions… so worth it! Unfortunately for us, my desire to relax got the best of us… I foolishly suggested we stay a bit longer, but really found myself regretting the extension once we got back on the road. The traffic had already escalated around 4pm, and it took over an hour to return. Needless to say, I need to learn to accommodate my life around the traffic when here.

Once we did make it back to Pasadena, we went out for sushi at Matsuri with our friends. The sushi out here did taste more fresh that what I’ve grown accustom to in Texas. Quite delicious!

Day four: Beautiful weather and traffic

2011-07-12T22:34:00.001-05:00

We started off the day bright and early, waking up in the frigid cold of the California mountains. Packing up the tent and our other belongings, we got on the road before 8am hoping to beat San Diego traffic on the way to downtown. Fortunately for us, the road was relatively clear and we made it to Balboa park before most of the shops opened.

Before actually making our way to the historic and memorable portion of the park, we got a bit sidetracked. It was at this point we ran into the now infamous “hobo with a claw” which just turned out to be a park employee with a grasping arm for litter clean up. After the brief detour, we made our way to the actual sites in the park. We toured the area with a quite informative park guide, and he gave us a fantastic overview of the historical and botanical aspects of the park. From there, we departed for lunch and found an In-and-Out burger shop. For a classic burger joint, the food was good, but compared too many of the fast food options, the food there paled.

The post lunch adventure in San Diego consisted of scaling the Cabrillo national monument along the Pacific. Exploration of the old San Diego light house and sighting the city from afar was incredibly relaxing and beautiful. From there, we departed for Los Angeles hoping to beat some of the afternoon traffic. Unfortunately for us, that did not happened and we spent a good two hours (plus) in traffic on the way to Pasadena. Although we were disgusted with the traffic, we had a phenomenal time with our friends in Pasadena. They really helped improve our moods with great food at a place called Daisy Mint (an Asian fusion restaurant). After dinner, exhaustion set in and we collapsed for the night!

Day three: Cacti and long drives

2011-07-11T22:31:00.000-05:00

Another early morning with a stop! Today we began with a drive through the Saguaro National Park to see some cacti. While we were impressed overall, it was sad to see that a long term drought has significantly reduced the number of cacti. Hopefully one day the cacti will make their resurgence! Once we passed through Saguaro, we got back on the road.

Today’s drive along I-8 (we branched off from I-10 to swing into San Diego on the way) turned out to be one of the more destitute drives I’ve ever done. For stretches of hundreds of miles there were little to no signs of inhabitation, and more dust storms than gas stations! When we finally made it to Yuma (on the border between Arizona and California, we were ecstatic to finally pass through a town with more than a couple hundred residents! From there, we made our way into California past the Sonoran sand dunes.

We settled down in Cuyamaca Rancho state park and set up our tent for the night. A quick hike into the wilderness only wet my appetite for hiking! Of course, the more astute reader might wonder how I composed this blog post… posthumously!

Day two: White sands and the open road

2011-07-10T22:16:00.000-05:00

We began today bright and early thanks to the time zone shift from Texas, and rightly so due to our tireless traveling plans. After a quick continental breakfast (still avoiding the caffeine for a few days even though I had a significant caffeine headache last night), we got on the road towards White sands in the Tularosa basin! Interestingly enough, the road out of Las Cruces to White sands passed between the White sands missile range, so technically we couldn’t pull off the road! Also a side note, I found out that we wouldn’t be able to visit the Trinity site, even if we had decided the extra several hundred miles was worth it. Access is only allowed twice a year! Ah well, some day I will make the pilgrimage!

When we arrived (arrival here was quite startling since the dunes appear out of nowhere!), we quickly started with a brief stop by the gift store to rent a sled for the dunes! From there we drove our way into the dunes. As we progressed further down the road into the dunes, the mounds became larger and the road quality became dismal! Eventually we found a spot where we could sled down the dunes with little interruption! The picture says it all! One thing that really caught my attention as soon as we arrived was the dearth of sound! We could only hear the wind and I could actually listen to my heart!

From the sands, we got back on the road making our way through New Mexico with a brief stop at a winery. By the mid-afternoon, we had made our way into Arizona and decided to turn in for the night before Tucson (in Benson). Thank goodness for Yelp yet again! We found a delicious local diner spot (Apple Farm) and had a cheap fantastic meal! Turning in early (again due to time shifts and early morning driving!), so take care till tomorrow!

Day one: The lonely stretch

2011-07-09T22:11:00.003-05:00

We began the first leg of our journey bright and early today. After bidding my parents and brother farewell (they had visited to help with the transition into the house), we embarked with El Paso as our destination for the evening! Feeling fresh and free, Stephanie and I talked for nearly four hours straight about completely detached topics. Because of the great conversation, the morning leg of the journey quickly passed by! Before we knew it, we had driven hundreds of miles through Fredericksburg and the hill country and into west Texas.

A quick stop in Ozona for lunch let us recharge for what we thought would be one of the more daunting drives of the trip. Unfortunately for us, the buffalo chicken lunch meet that we had brought along for sandwiches was already cloying when the cooler was opened… this would only get worse! I digress though! Thankfully we were able to switch off driving responsibilities often enough that neither of us would get totally exhausted. As such, we made such great time while driving that we made the decision to drive another hour to Las Cruces, NM after grabbing dinner in El Paso (a delicious place called Julios Café Corona which I’ll probably review on yelp!).

Monte Carlo, etc.

2011-07-02T17:06:00.001-05:00

Seems fairly appropriate to have a brief little discussion on the concepts of Monte Carlo simulations especially due to the royal wedding going on in Monaco today. Honestly, it is more important given the discussion that I started in the previous post. I mentioned this concept of the probability box for numeric pdf propagation as being more computationally efficient than that of the Monte Carlo techniques… but never mentioned what those actually are… how foolish of me! Anyways, I plan on rectifying that mistake now!

The concept of the Monte Carlo simulation (having really nothing to do with the casinos or anything of the sort) essentially boils down to computing the results of thousands of simulations with random effects in them. A very simple way of envisioning the simulations is to think of box on the ground that you have to push. Imagine that the weight of many boxes vary between 10 to 100 pounds with a majority of them having a weight around 50 pounds. Now imagine having to push each of these boxes a certain distance (say 1 mile). Let us say that we can measure the force you need to push each box… the Monte Carlo simulation takes the measurements for each of these required forces (how much effort required to push the boxes) and plots them in a histogram type graph… we can essentially generate the probability density function for the forces required to push this range of boxes. That is the full Monte Carlo case. A few other numerical uncertainty methods are out there too, so here it goes!

Much akin to the general Monte Carlo, the quasi-Monte Carlo uses randomness to generate simulation cases. However, unlike the general case, we attempt to speed up the process by deviating randomly about several chosen points. Thinking back to the box example, rather than selecting boxes purely at random from the range… we have a grid structure from which we randomly deviate such as to ensure the entire range of boxes are sampled. As such, we can drastically reduce the amount of boxes that we need to push! Huzzah!

Of course, some of the probability density propagation techniques which I’ve been looking into for dynamic systems actually further reduce computational complexity, but in an entirely different manner. Stick around to find out more about these techniques, which I should hopefully refine and discuss soon!

Intervals of probability for concise propagation

2011-07-01T16:36:00.000-05:00

Whoa, so I’ve been a tad busy this week with both visitations from Stephanie (the weekend till Thursday, which was awesome BTW) and then parents (Thursday till now) so my research has been on a hiatus until today essentially! With a sneak of reading here and there, I’ve more or less gotten little done that isn’t directly related to my class. I was hoping to finish the homework for the stochastic class as well as make significant headway into the research… but alas, we always hope for more than is physically possible. Anyways, I did manage to read a bit more about some of the derivative concepts from Dempster-Shafer evidence theory… leading to the ideas of probability boxes and the propagation of such objects through dynamic systems. Hopefully I can succinctly get a couple of these concepts across…

Computationally, there has been some interest in the use of intervals for simulation of systems as opposed to standard progressions (your Euler/Runge-Kutta types). Using intervals computationally can be more efficient for initial value problems, or so at least I have read. The idea basically is that rather than calculating deterministically the range of IVPs, we can just propagate singularly the interval and come up with the solution numerically efficiently. Naturally extending this concept of intervals into the statistical domain… we come up with this idea of a known interval of probability distribution functions. Rather than strictly a deterministic propagation of a probability density function, we can propagate an interval of functions… essentially forming an upper and lower bound of distributions. The interval of distributions is referred to as a probability distribution variable (kind of a strange choice for jargon..)

The concept of the probability box (p-box) follows from the discussion above simply. Rather than looking at the probability distribution variable (the interval of pdfs), we look at the cumulative probability functions… of which, you guessed it, we have a pair! In a nutshell, the propagation of the range of variances is propagated… The beauty of this entire procedure is that we ignore the necessity for thousands of simulations required by more standard Monte Carlo techniques!

Ultimately with the work of my dissertation, I hope to develop a straightforward early stage design technique which relies on the propagation of probabilities. Of course there are some other details that I’m currently hashing out…. I don’t want to quite disclose those quite yet, since this will in due course contribute to the discourse of knowledge.

Uncertainty, how uncertain

2011-06-24T16:07:00.003-05:00

Well, here we go! I decided that I would update my audience on essentially what I managed to look over today covering uncertainty in dynamic systems. Of course, I’ve discussed model uncertainty before, but I’ve never really delved into the potential sources of this misinformation. Looking into the types of parametric uncertainty that could potentially exist in a model of an uncertain system, we find that two primary types exist. In this post, I’ll refer to the types of uncertainty as aleatory and epistemic. Note, depending on which field of research you select literature from, the chosen vocabulary differs, but the formal concepts essentially remain the same. Anyhow, hopefully I can get these concepts across in a fairly straightforward manner!

Figure from Ref: The Value of using Imprecise Probabilities in Engineering Design. Aughenbaugh, Paredis.

As an engineer (especially one specializing in the area of dynamic system/control), we tend to model systems mathematically such that we can study them in great detail without having to spend a fortune on thousands of physical experiments (unless you’re the government or a large corporation, that is!). Of course attempting to model something accurately is not a trivial exercise. The process of trying to capture every aspect of something mathematically (imagine down to the level of each atom…) is beyond the capability of humanity (currently!) and thus we make simplifications to the modeling. Or if a process is not well understood, we could model things incorrectly! Well, the introduction of these simplifications/unknowns are what we term as epistemic uncertainty. Epistemic uncertainty can theoretically be eliminated if we’re capable of infinitely refining our knowledge of the system. We measure every angle, length, electron spin, etc…. Needless to say, there is a point of diminishing returns… investment net essentially zero returns!

The other type of uncertainty, aleatory, is irreducible. Basically this would taken into account the natural tendency of some devices/components to introduce uncertainty into the system. A prime example of this is a pressure sensor which records the pressure of a fluid thousands of times a second. Pressure transducers are notoriously noisy (meaning that the pressure reading fluctuates up and down erratically) such that uncertainty will always exist in a system with this type of measurement. Well... one could argue that one could purchase a more accurate sensor, improving the readings and lowering the noise… and one could draw a conclusion from this assessment that theoretically a perfect sensor could be developed to perform precise measurement sans noise! Problem solved, right? Eh, probably not (see Heisenberg uncertainty principle).

Research goals and more frequent updates

2011-06-22T13:49:00.001-05:00

Greetings my fellow netizens! Well the past few days have infused my life with a state of constant flux. A brief list of changes might provide a sense of what has been occurring over the past week. My sister had been through surgery twice (once planned and then another for complications) and has been in the ER on four separate occasions. I’ve moved my residence from an apartment to an actual house, of which it seems that I will be the principle caretaker. My two yearlong residence in the ETC basement lab has ended and I now reside in a comparatively upscale (windows!) cubical farm. My experiences so far have been extremely positive. Potentially the largest flux in my life is the ground shaking shift in my research. Rather than continuing my esoteric work on energy storage mechanisms and optimal synthesis techniques, I’ll now be addressing the propagation of uncertainty in the design of systems.

The primary question arises when one begins to ponder the effects of architecture design in the early stage iterations. Can we (given a design) predict the required energy for an operational time frame with some bounds of certainty? Rather than the traditional deterministic approach, I’ll be going about this estimation procedure somewhat differently. We’re going to have both parameter uncertainty and load/ source uncertainty. Given some knowledge of these uncertainties, we can model everything with certain probability density functions and thus observe how the uncertainty propagates through the system. The end result is the required energy (or conversely, the predicted remaining battery life) for a system (robotic ground vehicle/electric ship are my motivation).

With this new research project, I’ve been scanning the literature nearly nonstop while on campus. Of course, I am running into numerous topic of which I am little acquainted such that I’ve lots to learn. I want to (somewhat) guarantee readers of this blog that I will attempt to make regular (nearly daily if possible) updates focusing on my research. This will further motivate me to synthesize the material in my mind and explain it in more of a lay sense since I realize my typical readers are family/friends. Anyways, hold me to this promise readers!

Building confidence

2011-06-16T23:38:00.003-05:00

This summer, I’m taking a course (or rather a guinea pig for an actual future course) on estimation and control of stochastic systems. My advisor is considering offering this course in the future for graduate students, but wanted beta test this whole thing before publically offering it. Essentially the course is an extension of linear models, estimation (Luemberg, least squares etc.) and control to the probabilistic domain. Rather than designing a system which is robust to all deterministic uncertainty (worst case design), we account for the probabilistic nature of the system. Since the “worst-case” could nearly never occur, why design for it? Or if we do, can’t we ensure that the system doesn’t operate as if it remains in worse-case operation for all time.

Again however, we are modeling the system. With statistics and probability we can establish confidence intervals… but as I have discussed before, even these confidence intervals are models of reality. Given measurements over time, we can begin to establish the underlying structure of the population space for a given process. However, since systems are continuous entities (such as the number of decimals between zero and one), we run into a problem facing the frequentist approach to statistics… the probability density function which we construct itself contains a probabilistic nature. We can only establish a level of confidence that our modeled distribution represents an accurate model of the population space. And to make matters worse, we’d have to run an infinite number of experiments at every point in time… which there are infinite of!

However, I shouldn’t just bash the frequentist approach. Typically, the analysis and control of stochastic systems takes on the Bayesian worldview. From this stand point, the probability distributions are only a tool. A tool, aptly named the Bayesian inference, allows us to “pear” into the future via an inference. We infer from existing distribution what the future is “likely” to hold. Again, here we devolve into approximations of probability distribution… probability of a probability. Seems like you ultimately have an infinite recursion of uncertainty and probability. So… what does this all mean? Can we use these tools at all?

Of course we can! Just as in a similar manner we can use dynamic simulations of systems to predict the performance and develop necessary control algorithms. A certain level of confidence is necessary to establish confidence in the model… just as in stochastic systems, a certain level of confidence is required for our trust in our confidence intervals! We can take a similar take on reality… when can we ever be 100% confident in the nature of reality?

Graduate school and stress/anxiety

2011-06-07T17:01:00.004-05:00

Rather than my typical post format about my latest readings (research or otherwise) and my opinions on various topics, I’d like to address something close to home for me (and certainly a multitude of others). One of my current devotions of chunks of time is my graduate education. Those who know me, or follow this blog regularly know that I’ve been in graduate school for mechanical engineering for nearly three years now. Most of this time has been gratifying and I’m pleased with my decision to enroll! However, over the nearly three years, a silent agony has accumulated and has recently started to take its toll. Stress/anxiety.

Due to the constant nature of the graduate school experience, there is never a clear demarcation between school and free time. As such, someone devoted to research and studies becomes lost in the everlasting fields of knowledge… and it is hard to let go. Because of the pressure and anxiety I face constantly, I experienced several bouts of depression and felt unable to cope. Thankfully these experiences have passed. I have recently started some therapy to help me manage my stress and to help me reengage myself in other areas of my life that are also important.

I know there are probably many others out there with stories similar to mine, especially in the graduate environment. I gathered some resources to help anyone that is also in a similar predicament, and feel free to contact me or share your story as well.

Here are some links to help that I’ve found:

Fundamental Nature of Reality

2011-05-26T14:27:00.003-05:00

One of those persisting questions, beginning with the early great philosophers such as Democratis who spawned the concept of the indivisible atom as a basic unit to the modern science philosophers who delve into the repercussions of quantum physics on reality itself, remains as what forms the fundamental nature of reality. At the heart of what we experience and detect, what lies at the base of all of this. Science of course (through the ideas of radical empiricism), states that the nature of reality remains only what we can empirically test and observe. Theoretical models of reality only become actual scientific theories with the justification of data, and as such what we see is only an approximation of actuality.

Of course in the above statements, there is nothing radical or new. Essentially I’ve just restated problems encountered by humans in their attempts to further the understanding of what we encounter. One of the primary issues which persists to this day, is the concepts of objective reality. As a scientist, I have been train to model objective reality. But my “objective” reality is built up from the reality of certain particles which form cells which form me. But I, myself, am not a creature capable of comprehension of objectivity as I’ve been raised in a certain society and with a certain intellectual footprint. As such, each of these layers when pealed back remove part of my ability to detect what everything is at the base… like removal of silly putty from a newspaper, some of the text is lost. My gaps and holes in reality can only be filled in by other which have had different exposure.

We run into gapping maw of an issue here. The fundamental nature of reality can only ever be approximated to increasing orders of accuracy, but we can never establish say a metaphysics of reality. Why is this? Well, the issues becomes that with each creature that has perished, we’ve lost ability to grasp an aspect of reality. The arrow of time is unidirectional, and with the passage of time our fleeting glance at the fabric of reality locally slides. Only a local perturbation approximation is possible, and as a result complete comprehension of reality can only be just that… a model. As any engineer will cheerfully inform you though, a model of reality provides great insights and as such should be strived to obtain!

On Rain

2011-05-19T15:45:00.002-05:00

The rain inspires and delights some, but also distresses and irritates others. Nowadays I can firmly plant myself in the rain camp. I’m certain this wasn’t always the case for myself. However, with several years of fluctuating drought in central Texas, downpour days trigger a primal sense of enjoyment. A conjecture that has come to me in times of reflection is the need for further appreciation across the board of rain, and with that water. If society as a whole were to appreciate rain, and in conjunction nature itself, global empathy for the human existence would improve.

In modern times, our reliance on rain for nourishment has diminished severely and as such, so has our appreciation for it. Whereas the rain once was a sign from the gods, it is now an inconvenience at best. Only during the most severe droughts when the man-made reservoirs begin to dry and rations cause us to adjust our lifestyle do we begin to take notice. Rain and the weather more generally are one of the last bastions of nature that can regularly influence the modern citizen. Even deep within our fortresses of concrete and streaming media, weather pierces through and continues to persist. As such, we view this non-human controlled element as a nuisance and disregard it if at all possible. By retreating from even the weather element, we eliminate the last touch of nature and as such the last touch of natural empathy.

I believe that a full embracement of the cycle of the planet will lead to more empathy for the planet and by induction for all the life bearing elements, including humans. With modern culture, we’ve introduce a more open and free culture that has ever existed (to our knowledge) but in the process we have become withdrawn from our roots. This isolation could threaten the dynamic achievements of our species and result in the loss of the ledge on which we have scaled. A dual embrace of the benefits and our static roots are necessary for the preservation of our species… else we may experience a descent…

Imagine a cave (ok, totally stealing from Plato here, guys) with humanity as the residents. In this cramped space with humanity is a nourishing stream from which life has poured. Of course through blood, sweat, and tears over millennia humanity crawled from the depths of the cave and emerged into a cavernous space. In this space there are many possibilities that were never before possible, some of humanity is finally free from the confined cavity from which no options were allowed. However, if humanity were to forget the stream of the cave which they have known for eternity, they could just as well end up in the depths once again. Led astray by the new found freedom of the open cavern. We’re still animals, people like to forget that.

Engagement

2011-05-03T15:44:00.003-05:00

Although I am certain that all readers are already well aware of my current circumstances, I will announce this exciting news publically, as I am still overjoyed! Stephanie and I are officially engaged as of the second of May! I proposed to her in Fredericksburg, Texas after surprise get away in the hill country involving vineyards and a cabin retreat! She did say “yes!”, and I will never forget the look on her face when I got down on the knee and followed through with the question!

We’re still deciding on the ultimate date, but it appears as if the wedding will be sometime in April or November about 1.5 to 2 years away… although there is always the option of this fall! Hopefully within the next couple of weeks, we can sort this all out and hammer out the final date. Since neither of us is particularly drawn towards one month or the other, we might just ultimately decide via the price differences of the seasons. From there we can begin the real planning process! Of course, I will be keeping in touch with everyone about the process and will be sure to let everyone know what ultimately happens!

One last insult in the process

2011-04-29T13:36:00.008-05:00

It took years, but congress ultimately passed the First Responders bill, which provides the folks that provided the initial search and rescue for the Trade Center with healthcare. You would think that for such brave men and women, the healthcare issue would be straight forward (much akin to the military and healthcare!). But of course, the standard partisan politics got in the way of sanity and delayed the passage of this no brainer legislation for nine years! Finally culminating with the signature from the president in January, I thought the nightmare was over.

Boy, could I not be further from the truth! To further fester the wound of delay, it turns out that the people that apply for this program will have a background check to ensure that they’re not on the terrorist watch list… First responders to the 9/11 towers are going to be checked to ensure they’re not known terrorist, just let that sink in! John Stewart on the Daily Show illustrated the absurdity of this requirement just a few days ago. The whole idea that they should be cross checked seems to just come from a grand conspiracy. I’m still flabbergasted by the insanity that is this provision…

Essentially, by requiring this check, we are furthering the efficacy of terrorism. If people can sporadically attack us and then cause us to over-react such that we effectively change our way of life, then terrorism wins. I think we should take more cues from the Japanese recovery from the earthquake. They have shown resilience in the face of terror, and as such illustrated the capacity for human will!

On meditation

2011-04-25T18:45:00.002-05:00

Over the past couple of months, I have restarted regular (well, pseudo-regular) personal meditation. There are a lot of connotations attached with the concept of meditation, but I can assure you that there are myriad meditation techniques from which these subtexts arise. Of course, there is spiritual meditation, internal meditation, etc. What I have become somewhat interested in is the concept of singular focus. Meditation is one method through which focus can be sharpened and honed.

My thoughts are almost always jumbled and scattered, rushing from subject to subject. As such, I’m often caught off guard in conversations due to the needless chatter preventing me from focusing. After one too many “brain farts” resulting from thinking about other things at inopportune times, I decided to research potential concentration aids. One of the more promising solutions appeared to be meditation. Two common forms of self-meditation in the west are the concentrative and mindfulness forms. I’ve attempted both with moderate success.

While practicing concentrative meditation, one focuses intently on a single thing. Oftentimes, one begins with the breath. You can count each breath, in and out, until you reach ten. Then repeat. In addition to the counting, you should be well aware of the breath as it flows in and out, filling the lungs. The pressure should be apparent. Other thoughts drift in when focus is broken, but you just let the thought run its course, and then start over. By focusing intently on breathing only, the focus overall can be sharpen! I can vouch for the efficacy of the method. Although I would only consider myself an amateur, I’ve noticed marked improvement in concentration.

The random thoughts that are present while meditating have definitely decreased since I began the whole process. I find myself having to restart the count less and less and as a dual, I’ve found the chatter in the mind to subside when I focus intently. Essentially this is a risk free investment (other than time – 15 minutes a day) which I have found to have a positive influence in my life! At least that is what I keep telling Stephanie, haha!

Control, for control sake

2011-04-22T21:01:00.002-05:00

On one of my previous posts, I discussed the general idea of what control engineering is and what devices a control engineer might have helped to design. This time around, I am gearing this post more toward fledgling controls engineers (as if I'm not one myself) to discuss more philosophically what the field at the core represents. Of course, this is more of an opinion post that an absolute proof, but
that in essence is my point as well!

I've met many people that are interested in control theory and employing feedback in physical systems, but I am always surprised at the severity of the concern people have for absolute proofs of controller stability. So we have several ways to approach the concept of stability for control systems. We can analyze a system deterministically (usually worse-case parameter analysis) or stochastically (have to make some kind of probabilistic distribution assumption) and determine what the bounds of stability are for a given system and parameter perturbations. This can of course be conducted with linear or nonlinear systems without the loss of generality. However, note that in all of this analysis, we still rely on the model of the system and a model of the uncertainty of the plant! We always are physically modeling something, and thus when applying these system to reality, we cannot guarantee with absolute certainty that
something will be stable. Never.

I think people often forget that second part of control engineering. That we are still engineers. We establish confidence in designs and systems up to a point. Whether the tolerance is 0.1 certainty or 1e-10 certainty, there is still room for uncertainty. Likewise for a physically implemented system, we can establish confidence on the stability and performance of a controller, but not utmost absolute certainty as we can only approach that asymptotically. Like the Fukushima-Daiichi plants in Japan, they were designed to be externally robust against earthquakes of close to 0.5 g, but the unmodeled uncertainty was the large tsunami which struck soon thereafter.

The moral of the post is that while proofs of stability are all well and good, and often times very elegant. There is no such thing as an absolute guarantee! As an engineer we can just improve the confidence interval, but of course we ultimately reach a point of diminishing returns and settle with an established confidence.

One nation under tax

2011-04-20T18:43:00.003-05:00

Well since tax session has just passed us, and with all the political fire burning on this subject, I figured I would add my two cents on the matter. I think most citizens in this country are aware that the governmental budget really needs some repair to redirect the country on a stronger recovery into this century. The deficit is certainly an issue, and one can go about repairing problems in several ways. Of course as a constitutional democracy, we have historical reasons for governmental inefficiency and bureaucracy. The framers of the document having been scarred by the actions of the throne in the late 18th century, wanted to essentially create a a government that would only "just" work. They avoided creating a strong central government such that drastic changes could not be put into effect with every new candidate.

This is certainly self-evident with how presidential handovers are felt. No president enters office and directly influences us immediately. These effects are attenuated and delayed drastically such that the country can be viewed as a massive tanker ship. Each president and congress maintains control of the rudder for a minute. Of course after about a minute the effect of the rudder is finally felt by the ship overall, but that is when the next ship director takes over. Small deflections can only accomplish so much! I digress though, back to the tax discussion.

We can address the deficit in a simplified way by conducting two things: raise taxes (increase revenue), or cut spending. And in classic Washington style, we have a dichotomy down party lines with each side demanding the extreme. Quite clearly the solution to this deficit involves both methods of trim. Bush tax cuts cannot be extended anymore, they will bankrupt the country! And honestly, they should be eliminated across the board, not just on the rich. Tax loopholes should be eliminated as well, but that is easier said than done. As for spending cuts, there are many things that should be addressed. Entitlement programs need reform, certainly. But I am not convinced that eliminating these safety net programs altogether is ideal. By the time I am old enough to acquire social security, I hope the program takes on a new form all together. It is doubtful that I will have any funds there, so I save independently.

Well, I managed to create a post that is super idealized and probably means nothing. But for me, the idea is that career politicians and partisan bigotry will not solve the country’s problems. With the political system we have, it is already hard enough to accomplish anything, don't make it all the more difficult!

Back to the grind, difficult sometimes

2011-02-21T12:44:00.002-06:00

Do you ever have one of those weekends where you have sensory overload due to the levels of excitement and fun, and afterwards it’s hard to get back to work? Well, I believe I am experiencing the aftermath of BWE* syndrome. Since Stephanie can hardly visit Austin these days, the times she does have become so exciting and action filled. Even if we have to spend time working together, it is always better with her company!

This past weekend was filled with adventure all-around, stand-up comedy, drinks, hanging out with my sister and roomie, lots of cycling and amazing dogs! If only I had the time and space for a dog, we would have totally brought two home this time. A young dachshund-mix named Bordeaux was one of the best dogs we’d ever met at the shelter and it was hard to leave without adopting him right away… and to top it all off, we found an equally amazing older german shepherd who was so friendly and well-behaved… if only!

Of course, now I’m back to the PhD grind as usual and Stephanie is back in Houston dealing with the inextricable stresses of optometry school. I can only hope for another fantastic weekend like the one we just had!

*Best weekend ever

Civil unrest procures short term strain, long term

2011-02-11T12:42:00.000-06:00

Climaxing today with the resignation of Hosni Mubarak, the fall of a dictatorship demonstrates the continued human interest in self-rule. In the US, there seems to be some division between support and concern over the fall of an authoritarian figure, which seems to be unfounded looking at history through a statisticians lens. Pin-pointing one or two examples of authoritarian governmental collapse (the Iranian revolution seems to be a popular example) as an end all proof for the concern of a rising enemy are really unjustified. Looking though the peaceful revolutions of the past several hundred years, almost all of them end with stable peaceful self-governing democracies, or at least constitutional monarchies. Successful peaceful resistance, such as what we have witnessed in both Tunisia and Egypt, should almost certainly, via statistics, lead to peaceful self-governing countries.

Unfortunately for the US, we’ve had national interests in the Middle East for decades which has pushed politicians here to move for regional stability over regional encouragement for real democratization. The Soviets, Chinese, Europeans, and others have all dealt with similar repercussions which seem like they are the norm in global affairs. As disappointing as it might seem, the lack of real push for self-governance will probably always persist as long as autocrats have things we want.

Of course, through out the ages, we can pinpoint pseudo-democratic societies and attempt to trace a lineage from ancient peoples to the current era, but I believe that this only serves as a source for debate which really contributes little to the current debates. Of far greater importance to democratic societies are the practicalities and nuances that come with self-governance. While we could go into a detailed discussion of political theory and discourse harkening back to Locke and Montesquieu, I’m an engineer at heart and am much more interested in the realization of a working nation-state. Constructive democratic state-building relies heavily on technocrats in the modern era, which means that the mass of Egyptian educated have a large task of reshaping the country to guide it for decades to come.

On Control System

2011-01-22T22:32:00.002-06:00

One of my passions lies in the field of control theory. While the theory can be interesting from just a pure mathematical stand point, I find that the field truly shines in applications. When I introduce myself and inform people that I’m an engineer, or more informatively a mechanical engineer, people often imagine cars, airplanes and oil. All of which are true for many MEs, but for me and a handful of other mechanicals, we are interested in the control of systems (notably ones that move). Once I explain that far, people often think I work exclusively on robots… well, I have done some work on legged locomotion for robotic, but I would certainly not consider myself a roboticist.

The field of control systems is the study of making systems (be it natural or man-made) behave in a fashion that you want. This could range from an almost trivial example of maintaining the temperature in a room, to complex stabilizing controls on modern jet fighters. Control engineers make things operate properly. Now this might either seem simple or complex depending on who you are. And I would wholeheartedly agree with both parties. Controls can be very simple (in the case of very linear systems with little disturbance) or frightening complex (nonlinear or non-minimum phase systems). But most of the time, controls shouldn’t be taken for granted.

Nature has been quite effective at perfecting control over the millennia, as numerous impressive feedback systems exist in our bodies alone. Ion channels in neurons use feed forward control to transmit a signal across the neuron synapse. Our eyes have complex tracking mechanisms that rely on discrete control of movement due to the neurological delays in the processing. When we attempt to control a system, we apply the concepts of differential equations and linear algebra in various ways to achieve a desired control algorithm. Once we know, via simulation, that the controller is ready. Then we can actually deploy the controller. Control really shines when you have disturbances or unknown model uncertainties which prevent a design from just measuring input to output effects and just creating a map.

Next time you use a device that works, you can thank an engineer. And certainly a control engineer while you’re at it!

Powertrain control course

2010-12-11T13:45:00.000-06:00

In conjunction with my other commitments this past semester, I decided to take a course on advanced powertrain control. The course covered, in a broad sense, the transmission of power from sources to loads in various mobile and stationary powertrain applications. Of course, one of the primary focuses of the course was applications to automotive powertrains, but we did look at many other applications, such as wind turbines and ships. The professor for the course came in with a lot of industry experience and was able to give us a fair amount of insight into what kind of control is actually used (notably in the automotive industry).

Since there is a lot of current interest in hybrid vehicles, one of the pushes of the course was the hybrid electric vehicle. We discussed the overall powertrain architectures of these vehicles and how one would go about modeling them. We took a physics based approach to this course as opposed to data driven, and derived models for dynamics of the vehicle, ICEs, transmission, and the battery. For some in the class, these models would play an important role in coup de grace of the course, the final project. We also covered hydrogen fuel cell modeling for both supervisory control and servo level control, as well as wind turbine powertrains. Although we didn’t cover in depth control theory in this course (LMI controller synthesis, structure singular value robust analysis, passivity based controller, etc.), but rather focused on refining the basics (linear control theory, decoupling MIMO systems for single control, LQR optimal control).

As I already mentioned, a major focus of this course was the final project. My partner and I took a vastly different take on the project when compared to our colleagues. Rather than modeling a vehicle, we decided to go with a ship based project as we both had research experience on ship based power systems. Our project was a feasibility analysis on a hybrid propulsion system for model ship. In conjunction with the traditional propeller propulsion, we coupled a Flettner rotor wind based system which operates using the Magnus effect. We optimized the system using dynamic programming given real world wind cycles, and it turned out that hybridizing the vessel could result in energy savings overall. In an attempt to validate the simulation results, we began to construct a Flettner rotor, but ended up scrapping the build due to time constraints.Overall, I’d recommend this class to anyone considering it. Though as a prerequisite, I’d recommend having a fairly strong grasp of basic control concepts.

On Heavy Rain

2010-12-06T00:54:00.002-06:00

My girlfriend’s family recently bought a PS3 with a few games. One of the games that they eventually ended up purchasing was Heavy Rain. I had my reservations on initially hearing about the game. During my gaming history, I’ve never encountered a game were cut scenes are numerous and enjoyed the game! The newer Final Fantasy games were like this and always perturbed the hell out of me! I would find myself walking a few steps in the game and then I’d be loading then watching another cut scene. Of course, these comment perhaps paint me as a non-story driven gamer… however, that could not be further from the truth. I’ve always desired games with excellent story driven plot lines, such as Chrono Trigger or X, where the story is experienced as you play the game as to something inherently separate from the game itself. Heavy Rain is close to bridging that gap for me, and perhaps a couple of game iterations down the road, we’ll have perfect game in my eyes.

I don’t really want to reveal too much about the storyline of the game, as that is an intrinsic feature of the feel to the game and I don’t want to detract from it. The general plot is that you take control of four different characters in a mystery/crime genre plot. All of your choices and actions in the game propagate through the storyline and ultimately result in different possible endings. The controls are interesting. PS games have been adopting the interactive cut scenes where elements in a cut scene require reaction from the player through specific button combos, and Heavy Rain continues down this path. In this way, you feel more connected to the cut scene. However, the third person game play feels force most of the time, and the camera angles (like most 3d third person games) can at times become aggravating. I’ve always wondered why so many developers have such animosity towards the first person camera mode. Not only do you feel more connected, but you also eliminate the nuisance of idiotic camera angles which detract from the gaming experience. Had the game been first player during the standard game mode, I actually wouldn’t have much negative to remark about the game!

Overall, watching the game makes me wish that I had a PS3 to experience more of the varied endings of the game. Perhaps one day, it’ll be released to the PC where all games should be played anyways!

Qualified!

2010-12-01T19:28:00.000-06:00

As of a few weeks ago, I can officially refer to myself as a PhD candidate as opposed to the more lackluster title of PhD student. It is set in stone now, I’ve passed my qualifying exams and I’m now ready to move on to the meat of the doctoral degree… proposing research and then the final defense! The whole process took a good five months to complete in its entirety. Beginning with the oral exams, which involves complete knowledge of undergraduate mechanical engineering curriculum, we finished out with a mini-research project which lasted another couple of months. I spent a good chunk of the summer solidifying engineering concepts in my mind. A group of several of us were taking the exam at the end of the summer and thus we spent many days and nights reviewing concepts and discussing problems. From nearly relearning some concepts in thermal fluid systems, to going crazy with three dimensional multi-body dynamical equations, I actually felt like the review of engineering concepts was beneficial to me in the long run. I ultimately passed the exam and then moved on to the research portion.

The research portion was more of an agonizing experience in my opinion than the oral exam. Even though there was an initial intimidation factor involve with the oral examination, working problems on the board in front of the faculty, once the momentum of the exam built up, by Netwon’s first law, I felt unstoppable! On the other hand, the research was a drawn out process of confusion. One of the main aggravating factors of the research portion of the exam is the isolation of the project. For any other research I had ever conducted prior to the qualifying exams, I was able to bounce ideas off of colleges and faculty members. However, for the research portion, we were required to work completely solo on this exam for the entire two month period. A sense of worry instilled itself in me during this process due to my aggrandized views of faculty expectations. I doubted my research project’s depth (turns out that a simple example is ideal, no need to dabble in the complex details for such a short project), and I fretted that my overall results were not addressing my hypothesis to the extent that all the members of my committee desired (turns out that I nailed it pretty much spot on…). All my doubts were abated, and I found out, to my delight, that my work was fine, and all the doubting was for nothing!

My word of advice to all those that will follow in my footsteps is to not over-analyze everything, since that only leads to unnecessary worries. Focus on your studies for the oral portion of the exam, and know the basics like the back of your hand. For the research portion, select a manageable project and the faculty will help you flesh out the details of the hypothesis. Then ensure that you know your references inside and out, and don’t quote anything without knowing for sure if it is true. The faculty will ask you where you found your claims and how (even if it is a journal paper) you know for certain that the results are sound. Essentially, use your best judgment and don’t report anything that you do not understand! If you follow that basic advice and can stomach the five months that this all takes, congrats… you’re on your way to becoming a PhD candidate too!

Houston and the Electric Car

2010-11-21T19:23:00.001-06:00

Honestly, Houston is probably one of the best places to start with an electric car infrastructure. Over 80% of the people there commute on the highways, so converting even a small percentage of these drives would result in a reduction of thousands of ICE cars.

Houston Gets Private Electric Car Charging Network - GOOD

Houston, Texas, may end up being the first American city with a great electric car charging infrastructure. A company with the phonically awkward name of NRG Energy is rolling out "the world's first privately funded comprehensive electric vehicle ecosystem." The system (or "ecosystem," in their overwrought marketing speak) is called eVgo and it employs a very interesting business model. NRG is...

Rejection of universal appeal

2010-11-20T19:26:00.000-06:00

Rhetoric... oh how letting a law expiring can be framed in various ways to benefit politicians! Just like the expiration of the START treaty... it's also being framed as an Obama action. Apparently rushing the inspectors back to Russia is a crime against America according to Kyl... how about some interest in our own country for once. Current politicians solidify in my head that libertarianism in certain incarnations is completely impossible. Self interest can be completely detrimental to a country as a whole. E.g. Hannible's invasion of Rome during the second Punic war could have resulted in a dramatic victory for the Carthaginians, but he held back. History has all but forgotten the existence of the northern african empire. So it goes...

Against A Payroll Tax Holiday - The Daily Dish | By Andrew Sullivan

Bruce Bartlett hates the idea. It seemed like a decent one to me, until I read:
What are the odds that Republicans will ever allow this one-year tax holiday to expire?
They wrote the Bush tax cuts with explicit expiration dates and then when it came time for the law they wrote to take effect exactly as they wrote it, they said any failure to extend them permanently would constitute the biggest tax increase in history. Sadly, Obama allowed himself to fall into the Republican trap, but that's another story. My point is that if allowing the Bush tax cuts to expire is the biggest tax increase in history, one that Republicans claim would decimate a still-fragile economy, then surely expiration of a payroll tax holiday would also constitute a massive tax increase on the working people of America. And what are the odds that the economy won't still be fragile a year from now? Zero, I would say.

History will remember...

2010-11-16T22:29:00.000-06:00

But he's a maverick!! Seriously though, studies conducted by the military in the past (Korean war era) found that there would not be a breakdown in "cohesion" of the forces if the military was integrated... just one more stone to step forward on toward full integration. We're losing valuable military resources in rejecting people because of who they are....

Just Your 19th Flip Flop - Talking Points Memo

Rachel Maddow rips John McCain apart for now deciding that we probably shouldn't repeal DADT even if the military's internal study -- which he earlier said should settle the matter -- determines there's no harm to repealing the policy.

Upcoming 100km ride!

2010-10-31T22:15:00.002-05:00

Next Saturday, Stephanie and I will be biking from Austin to New Braunfels, TX during the Wurst ride. The two of us have progressively gotten more serious about cycling since I bought a low-end road bike last year for commuting. I upgraded my bike recently and Stephanie decided to get one as well! Ever since we’ve both had bikes, our rides have gotten progressively longer and more enjoyable! Whenever she visits Austin, getting away from school for a weekend, we try to ride at least a couple of times. One of our rides at the Veloway (a closed off paved area for bikes and roller blading only) in southern Austin helped us to stumble upon the Wurst ride.

After riding for an hour or so at the Veloway, Stephanie and I met a guy who claimed to have a “Pee-wee Hermann bike” as it had all the “bells and whistles.” We chatted with him for a while about cycling and bike maintenance, and then he informed us of the “Wurst ride” which was actually his first serious sanctioned ride. At that point, the two of us decided to prep for that ride and vowed to finish! The two of us are quite involved with our studies right now, so hopefully our marginal preparation will see us through the ride!

Perturbed Politics

2010-10-27T18:14:00.000-05:00

The current global political playing field has taken an interesting form since beginning of the great global recession. In comparison to the structure of communication during the great global depression during the 1930’s, media coverage of the severity of the recession could potentially saturate the 24/7 news cycle. However, the fixation of the media machine on trivial matters often overshadows the real issues at hand. We’ve been focusing too much on congressional failures, balloon boys and the like… the real focus of the country should be recovery. We should insure that given these tough times, we pull together and make the best of them. I’m sick of the disrespectful political bantering that continues to go on daily… and I’m afraid that it won’t just go away come November 2^nd.

In this time of instantaneous communication, one would think that I would be more aware of the hard times encountered around our own country. Most parts of Texas have weathered the recession fairly well with unemployment rates stabilized around 6-7%. It almost seems like the pockets of relative job stability are insulated from the pain felt where the job markets have collapsed. I wish the media would take the time and put on specials about the actual suffering going on in this country. Yes, it would be depressing, and yes, perhaps the ratings would suffer… but perhaps though the realization of the difficulty our country is in, people would be willing to re-embrace the American spirit. Ben Franklin’s “Unite or die” is in need of real revival.

Writer's Block

2010-10-19T00:10:00.002-05:00

Have you ever had one of those days where you can seem to place words in your writing? Or one of those days where what you write seems mangled and forced? I’m having one of those days right now…. I take that back, I am not having a bad writing day as is evident by the fact that I’m able to hash this post out right now. My issues is my topic… unfortunately, my current research topic is not too my liking. This whole project has felt forced and I’ve been worried the entire time about satisfying multiple faculty personalities. Every sentence I write for this short paper feels as if a prisoner still shackled to a ball and chain is given a chance to run for freedom. I frantically attempt to write as much as possible, but as much as I write, I’m going nowhere. At this point in the game, however, I still have time…. the prisoner still can clamor for freedom… I am truly hoping that given a few days’ time, that my writing clarity and quality will improve and I can begin worrying about other issues facing me currently, like how to get this ball and chain off…

Day 2 - Post Sinus Op

2010-07-30T11:12:00.002-05:00

I had my sinus surgery yesterday morning. After much nerve wracking anticipation, I was prepped and underwent the concha bullosa resection procedure with additional repair of my deviated septum. Everything during the procedure went flawlessly, and I'm already feeling much better! I've spent the past day and a half recovering, but compared to my wisdom teeth removal, this recovery seems more rapid! Hmm, perhaps this is because I can still eat anything I want, rather than a restricted soft diet after the wisdom teeth!! Eating/drinking after the surgery was especially reinvigorating, due to the mandatory midnight fasting. Subways tasted delicious, even with added noise juices!

After the surgery, I spent most of the day relaxing and watching movies or playing video games... and switching out nose gauze to capture all the noise drainage. (Boy, am I glad that is over with!) Honestly, the whole ordeal was not too bad at all, oozing nose with some pain that was never worse than with the concha. Perhaps since I am young, the recovery process is more straightforward? Props to my sister for helping me through the day, I really appreciated the help Renee! :)

Today, I woke up with a dry nose and promptly irrigated it with saline solution. The oozing from the day before had ceased, and now my nose has only been invested with blood boogers. I started the medications for the antibacterial and the anti-inflammatory along with occasional painkillers to mitigate the pain. All in all, the pain has ceased and I've pretty much stopped the painkiller usage. I was able to venture outside for awhile today, to pay rent and go to Wheatsville. If only my nose wasn't still so stuffy... smells today were a bit off (tinged with blood??) All in all though, great day of recovery!

Hoping to spend some time tomorrow studying for quals! Perhaps a bit ambitious, but a little ambition never hurts now and then! I can't wait till next weekend too! I miss Stephanie so much and she hopefully will make it up here next weekend! <3

Concha Prelims

2010-07-16T10:00:00.003-05:00

So I'm finally biting the bullet and having surgery on my sinuses, specifically to correct my concha bullosa. After nearly 5 months of near constant pressure and pain in my face, I went to another doctor and he noted that since the medication that I was prescribed really did not provide long term relief, that the only real next options are surgical correction or continued dosage increase of a corticoid steroid until I have relief. Since my concha is fairly sizable (apparently resulting from facial trauma from childhood), I should experience noticeable relief.

Fortunately this corrective surgery is relatively minor as far as surgeries are concerned. The procedure is less minor than having wisdom teeth removed, which I've already had done. Plus, it is an entirely non-invasive procedure which is performed entirely through the nostrils via a guided endoscope. I should be in and out within an hour or two! Yay modern medicine! I kind of hope I can see the procedure on film! (I already watched some on the youtubes!) Of course I am slightly worried about possible complications, but hopefully all will go well!

If all goes well, I should be in and out. Then I'll get right back to studying for my qualifying exams which loom just over the horizon. Over the past couple of weeks, I've divided my time between both research and studying. However, with the exam a little over a month away, I've begun to focus nearly exclusively on studying. Dang this exam! Anyhow, I figure after the surgery, I will try to document my symptoms and my overall moral. Perhaps that will be useful to others out there with a similar problem.

Stephanie will be here this afternoon! :D

Camping adventure - Spoilers, it fails

2010-06-16T17:11:00.006-05:00

For the first time since some time in high school, I went camping. Having been in the boy scouts for most of my childhood, I experienced quite a range of camping experiences, but in some ways, those experiences did not prepare me for this most recent camping experience (loud peoples). Stephanie and I went for an over night stay at Pace Bend park which is about an hour away from Austin. For our first camping experience together, we were actually wanting to hike to a primitive site and set up in the wilderness, but unfortunately (or perhaps not) the primitive sites in Pace Bend are all right next to roads. The sites themselves were very nice though!

This easy access to the campsites wasn’t really the main disappointment for this trip. In fact, mostly this camping experience was great and we had a fantastic time. The main issue were the talkative peoples that would randomly talk for 5-10 minutes at night till around 3 am in the morning and the humidity that never dissipated. By the time the guys finally stopped their erratic chatter, I had all but given up on sleeping. Stephanie and I left early in the morning so that we could return and properly sleep without talkative people and humidity.

Well, with the bad stuff out of the way… Stephanie and I had a great time other than the lack of sleep! We were able to swim in Lake Travis, which was literally 20 feet from our tent and probably contributed considerably to the humidity there! We were also able to make Smores, tell scary stories, look at the stars and explore the nearby terrain. Ah, we also acquainted ourselves with the quaint latrine at the site. I hadn’t see one of those since high school, and that is a good thing.

Probably one of the most random aspects of this trip was the great German food we had for dinner. On the way out to Pace Bend on 71, we saw a Bavarian food restaurant and we decided that we must have German food for dinner. I had a bratwurst sample plate with various mustards, latkes, paprika rice, and a pretzel. Stephanie had the fleishpflanzl, which was ground beef/pork with onions and a white wine sauce… she won! Overall, awesome camping trip other than the lack of sleep!

Camping 101

2010-06-16T17:11:00.005-05:00

This easy access to the campsites wasn’t really the main disappointment for this trip. In fact, mostly this camping experience was great and we had a fantastic time. The main issue were the talkative peoples that would randomly talk for 5-10 minutes at night till around 3 am in the morning and the humidity that never dissipated. By the time the guys finally stopped their erratic chatter, I had all but given up on sleeping. Stephanie and I left early in the morning so that we could return and properly sleep without talkative people and humidity.

Well, with the bad stuff out of the way… Stephanie and I had a great time other than the lack of sleep! We were able to swim in Lake Travis, which was literally 20 feet from our tent! (This probably contributed considerably to the humidity there!) We were also able to make Smores, tell scary stories, look at the stars and explore the nearby terrain. Ah, we also acquainted ourselves with the quaint latrine at the site. I hadn’t see or used one of those since high school, and that, I assure you, is a good thing. No latrine nostalgia necessary!

Probably one of the most random aspects of this trip was the great German food we had for dinner. On the way out to Pace Bend on 71, we saw a Bavarian food restaurant (Ilsa's Kitchen), and we decided that we must have German food for dinner. I had a bratwurst sample plate with various mustards, latkes, paprika rice, and a pretzel. Stephanie had the fleishpflanzl, which was ground beef/pork with onions and a white wine sauce… you won, Stephanie! Overall, awesome camping trip other than the lack of sleep!

Next Steps

2010-06-09T23:19:00.002-05:00

This upcoming summer is loaded with graduate school activities! Hopefully fairly soon, I will be able to shift my focus from research and writing to focus more on studying for my qualifying exams. Next week, my final version of my ASME DSC conference paper is due. Additionally, the past couple of weeks have involved copious amounts of literature reading and comprehension. Of course, these activities drain lots of energy and require lots of concentration. To top it off, a lot of times I feel like I’m running in circles with parts of my research which can sap motivation like nothing else!

However, more recently, I have been tending toward a more over arching analytical design technique which might optimally divide energy storage needs in a system between dynamic and switched storage. This also requires consideration of the system controller. I need to hash out this technique quite a bit, but the end result could be relatively interesting. Perhaps even a PhD dissertation!

I’m starting to worry more and more about my upcoming qualifying exams. Even though these exams are in mid-August some time, we’re essentially tested over the vast majority of undergraduate engineering knowledge (see last post). I’ve begun to review certain bits of material, but have yet to begin truly working out problems. Hopefully, that will begin to happen soon.

With all this school related stuff, I still manage to squeeze some fun in here and there! Stephanie and I have a great time every time she visits Austin. Likewise when I visit Houston! She is going to be here this coming weekend, and I am already super stoked! Our tentative plans include camping! Hopefully I’ll update and inform everyone how this weekend is!

Qualifiers Time - Route to Candidacy

2010-06-03T23:00:00.003-05:00

More or Less What I need to Know:

1. Thermal Fluids
1.1. Control Volume Analysis
A) Reynold’s Transport Theorem
B) Continuity Equation
C) Linear Momentum Equation
D) Angular Momentum Equation
E) Energy Equation
i. Bernoulli’s Equation
1.2. Differential Analysis
A) Continuity Equation
B) Linear Momentum
i. Euler’s Equation (Inviscid flow)
ii. Navier Stokes (Newtonian fluid)
C) The Heat Equation
1.3. Dimensional Analysis, Similarity
A) Dimensional Homogeneity
B) Rules for Nondimensionalizing Equations
C) Standard nondimensional numbers
i. Reynold’s—laminar/transition/turbulent
ii. Mach—incompressible/compressible
1.4. Fluids
A) Hydrostatics
i. Barometer
ii. Manometry
iii. Forces on a plane, submerged surface
iv. Forces on a curved, submerged surface
v. Buoyancy and stability of floating objects
vi. Uniform linear acceleration
vii. Rigid body rotation
B) Boundary Volume Flows
i. Linear Momentum
ii. Angular Momentum
iii. Bernoulli’s Equation
C) Pipe Flow
i. Laminar flow solution
ii. Turbulent flow qualitative difference
iii. Flow between two plates (Couette flow)
D) Boundary Layer Flow
i. Flat Plate
ii. Drag
E) Inviscid Incompressible Flow
i. Continuity Equation
ii. Momentum Equation
iii. Boundary Conditions
iv. Elementary Plane-Flow Solutions and their Superposition
v. Flow Past a Cylinder with Circulation
vi. Kutta-Joukowski Lift Theorem
F) Compressible Flow
i. Perfect Gas State Equations
ii. Adiabatic Isentropic Process
iii. Diffuser and Nozzle Flow
G) Open Channel Flow
1.5. Heat Transfer
A) The Heat Equation
B) Boundary Conditions
C) Conduction with Equivalent Electrical Circuits
D) Lumped Capacitance
E) PDE Solutions
F) Pipe Flow
1.6. Thermodynamics
A) State diagrams
B) Enthalpy
C) Quality
D) Ideal Gas relations
E) 1st Law of Thermodynamics
F) 2nd Law of Thermodynamics
G) Entropy
H) 3rd Law of Thermodynamics
I) Gibbs Equation
J) Isentropic Process for an Ideal Gas
K) Power Cycles
i. Otto
ii. Diesel
iii. Brayton
iv. Rankine
v. Refrigerator
vi. Heat Pump

2. Dynamics and Controls
2.1. Area/Volume Properties
A) 1st Moment (Centroids)
B) 2nd Moment (Inertia)
i. Parallel Axis Theorem
C) Polar Moment of Inertia
D) Principle Axes
E) Inertia Tensor
F) 2nd Order Tensor Transformation
2.2. Dynamics (formulating the differential equation)
A) Vibrations of mass, spring, damper systems
B) Kinematics of a Particle
i. Velocity and Acceleration on a path
ii. Translational relative velocity and acceleration
C) Linear and Angular Momentum
D) Rigid Body Kinematics
E) Rigid Body Dynamics
2.3. Laplace Transform
2.4. Partial Fraction Expansion
2.5. 2nd Order Response
A) Peak Time
B) Settling Time
C) % Overshoot
D) Affect of adding a pole or a zero (preview of PD and PI control)
2.6. Stability
A) Routh-Hurwitz Stability Criterion and the Routh Table
2.7. Steady-State Error
A) Step, Ramp, Parabola
2.8. Root Locus
A) PD, Lead, PI, Lag, PID, Lead-Lag Control
2.9. Frequency Response
A) Bode Plot
B) Lead, Lag, Lead-Lag Control

3. Mechanics of Materials
3.1. Hooke’s Law in tension and shear
3.2. Axially loaded members
3.3. Strain Energy
3.4. Dynamic Loading
3.5. Fatigue
3.6. Torsion
3.7. Shear and Moments in Beams
3.8. Stresses in Beams
3.9. Deflections of Beams
3.10. Buckling of Columns
3.11. Plain Stress
A) Principle Stresses and Mohr’s Circle
3.12. 3D Stress
A) Principle Stresses and Mohr’s Circle
3.13. Machine Elements
3.14. Trusses
3.15. Cables and Chains
3.16. Friction
A) Belts
B) Threads
C) Rolling Resistance
3.17. Pulley Systems

Gradient from the City

2010-05-28T15:58:00.002-05:00

During my most recent journey from Houston to Austin, conceivably due to an atypical state of lucidity, I happened to notice dramatically more wildlife in the areas surrounding the highway. Perhaps this heightened state of nature awareness actually detracted from my driving ability, but not only did I make it to Austin in one piece, my travel time was excellent. I write this post not as a boastful gesture about my innate ability for multitasking while driving, which I don’t really posses, but as a statement of concern for the other voiceless inhabitants of Texas and their diminishing habitat.

Our cities are ever expanding and populations growing. This is a sign of economic growth and prosperity and should be encouraged. However, as much as want to encourage economic growth, I would like to see more concern over the preservation of existing nature. Much like American culture, American cities have a tendency to grow out and not grow up. We expand out due to the relative cheapness of land here and not upwards even though American innovators are responsible for the skyscraper as we know it.

Furthermore, the American tendency and reliance for personal transportation is only further intensified with urban sprawl. For some reason, even though a majority of people commute in the same general direction in American cities, most of the large metropolitan centers, with some exceptions, lack reliable mass transportation from suburb to urban. A new generation of infrastructure improvement could remedy this situation, but for new modes of transportation to become a mainstay, the culture must change too.

For the sake of the silent ones, we must begin to change. A restructuring of both land and culture must occur within the next century for the preservation of both the animal and human way of life. We must realize that the American dream is not necessarily becoming a homeowner with land, that is the past. The true dream is the opportunity to pursue dreams and the ability to care for the ground on which we all stand.

The strengths of the free market… and weaknesses

2010-05-17T00:39:00.002-05:00

I am a proponent of the free market in many areas of the economy. Free market economies encourage healthy competition and eliminate ineffective and wasteful components of businesses. For many types of business, this form of interaction is not only good, but an optimal method of economic transaction. Examples of great free market businesses are the construction industry, the restaurant industry (and many other types of small service industry businesses), and entrepreneurialism in general. In industries like these, the free market spurs growth for the entire economy by rewarding those with good ideas and hard work.

However, unlike some free market fan-boys, I do not think that the free market is 100% applicable across the board. There are many types of business which require some form of regulation since the free market almost always encourages short-cuts and shoddy work (see my last post). Examples, in my opinion of these types of economies, are the health care industry, the financial industry and industries which are intertwined with the environment. Since I have more or less addressed the environmental issues in my last post, I’ll tackle the other too issues for now and will most likely elaborate in the future.

I know I have mentioned many things about the health care industry and the reforms in the past, but I want to again touch on the importance of early and preventative health care. To procure an example of a free market health care system, one needs to look no further than the United States. We have some of the best medical technologies in the world and we pay exorbitant amounts of money for access to this technology and science. However, even with this advanced technologies, many countries with far less have citizens that live considerably longer with less health defects. Rather than focusing on the “flat of the curve” technologies, we should avoid free market health care, and focus on preventative care. Preventative care does not have nearly the profit of free market care, but the results for the health of the nation would be drastic.

Another area in which I feel that the free market does not perform adequately is the financial industry. I don’t believe that we should completely remove the market aspect of finances, but too often the careless gambles of some investors are rewarded and cause large pains for many others. The stock market itself is a free market gem, meant for corporations for sell stock to investors for capital for growth. This free market ideal has crumbled into a buy/sell orgy of derivatives trading and hedging which defeat many of the original ideals of the markets. I’ll probably agree with many and say that many of these issues across with the passage of the Glass-Stegall act which allowed financial and investment banks to combine. Banks where people take business loans could now invest in mortgages and stocks, increasing the risk for everyone. Until these bank shrink in size, the free-market in the financial industry deals with too much of too many people’s money.

Scapegoat for a spill

2010-05-13T21:12:00.004-05:00

If you are not appalled by the recent spill in the Gulf of Mexico, than I am pretty sure you're not human. This disaster is a horrible, yet completely preventable mess that could have been stopped had a company headed the warnings of the faults of the Deepwater Horizon platform. Or is this disaster purely the fault of irresponsible actions of a corporation? Who is BP serving?

The answer is simple. People. BP is serving the demands of people and especially the citizens of the US. Our insatiable demand for inexpensive crude has encouraged sloppy work and cheap solution for oil production. If BP had taken all precautions to prevent this disaster, they would have been put at a competitive disadvantage against the other major oil producing companies.

The apparent carelessness of the oil companies is only a response to the increasing demand for cheap gasoline and oil products. When gas prices rise, people complain and blame oil companies for artificially inflating prices. Unfortunately, this is typically not the case, as rising prices beyond the expected price of consumers could result in decreased sales. The companies are bound inexplicably to us. (or US)

When we look for a scapegoat for a huge problem like the current oil spill, it's easy to blame the company at fault, like BP. What we should really do is look inside ourselves and see the connection between us and this spill. It is closer to home than you might think.

Woah, Masters?

2010-05-12T19:30:00.002-05:00

Well, I haven't had terribly much time lately to update my blog seeing as both a final project and a master's thesis all piled up there for a bit. However, as of today I have officially completed all my tasks to earn a Masters of Science in Engineering! Of course you would think this would be cause for celebration, and in some ways, it is. But unfortunately, most of us that are continuing for a PhD really don't feel too much relief as of yet.

Actually, we'll probably feel no relief until we're finished with everything! This upcoming summer will be filled with a multitude of activities. First and foremost, I will be beginning my study marathon preparing for my PhD qualifying exams. Starting with dynamics/controls, then thermodynamics, and finally machine design. This studying ordeal will most likely take the majority of the summer.

Another task that I will likely face over the summer is writing a journal paper. I've written a couple of conference papers on my research, and the next step for my research that I did for my masters is to put everything into a journal paper for publication. I'm not terribly sure when this process will begin, but I surmise that paper writing will begin this summer as well.

I've got to find time for relaxation as well! Who knows how things will turn out!

Applied Religion

2010-04-22T15:01:00.002-05:00

I’ve read many articles advocating for the purging of television from your life. They argue that the average American watches a few hours of tv a day, which could be constructively utilized elsewhere improving the community or personal development. I am going to suggest, hopefully not offending, that religious services should take place not in a closed religious setting but rather as a community improvement session.

In a similar manner to television viewing, many religions spend time every week in a service of worship. Rather than one hour or so a week of religious service, shouldn’t the members of a religion apply the teachings in real life for their worship by having volunteer sessions rather than a service. I have met so many people that essentially separate what they hear in the services from what actually happens in their lives. I would call that a hypocrite. Though this isn’t always the case, I feel that services encourage that type of behavior. Why not practice rather than preach??

I am heavily reminded of my undergraduate education in engineering when I think of this problem. You learn some theory in class, but the true learning takes place while doing homework and working in the labs. In a similar manner, real morals and ideals are learned in your daily life rather than a one hour weekly service which may or may not benefit you.

For a true reinvigoration of religion/morality, I advocate for applied religion. Rather than meeting once a week for a service, meet once a week and volunteer. Communities across the United States are in dire need for volunteers. Flying to Africa or South America is great, but we have so many problems that need sorting out here, why not start at home.

Life and Boredom

2010-04-08T00:14:00.000-05:00

The past couple of years due to my significant work load increase due to graduate school, I have felt as if there is always something to finish or to begin. What people say about advanced education is very true in a sense. You finish high school feeling like college will just round out what you’ve already learned (which for some reason seems like a lot at the time). Then during and after college, you feel good having learned (at least in the case of engineering) a knowledge basis for a career. For me, the completion of college definitely did not provide a sense of invulnerability. Now that I am in graduate school, I learn new material and concepts daily but even within my field there is always more to learn!

I guess the whole reason of this post is that sometimes I wonder how people experience so much boredom. Of course, back in high school I remember encountering boredom every so often, but even in college there was always so much going on (course work, social, exercise, video games, etc.). My advice to someone that feels bored… find something…anything, that you enjoy and pour your heart into it! Even if what you like doing can only amount to a hobby, be the best hobbyist you can be! You only have a single life with which to devote your time, and wasting time is wasting life!

Time as Transient

2010-03-31T15:40:00.002-05:00

Why does time seem to continue to speed up more and more as time goes by? I swear, this sometimes confuses me to no end. Even though many days seem long and difficult, on the whole time seems shorter now. Is this because of decreased attention spans or becoming less mindful as I age? Potentially.

Days that seem to last forever and that are enjoyable are the days that I savor every moment of. When Stephanie is here in Austin, I tend to enjoy my time considerably more and tend to recall every moment with ease. On the other hand, a week of grinding out thousands of words for my thesis will fly by in a blink of an eye. Not only will that surprise me, but also I don’t seem to appreciate the magnitude of work accomplished during that week.

I have a feeling that if I am able to persistently increase my mindfulness during my daily life, time might seem more worth savoring. I think over the next few weeks as the pressure of the thesis ramps up, I will attempt to be more mindful and pay attention to things I normally do not. Here is a list of my ideas:

Different bike routes to campus, not only that but actually pay attention during the ride to scenery and people. Note what is going on, while still avoiding accidents.
Make and effort to take more pictures. Stopping to take a picture not only increases the recollection of a moment, but also provides a digital memory for much later.
Put forth an effort to go over achievements of the day. I think this is especially important since I often dismiss my own good work due to my familiarity with it.

Concha Bullosa, Allergies and Me

2010-03-24T19:24:00.002-05:00

Allergens combined with a known anatomical concha bullosa are a pain in the neck! The past week I have been having allergenic flare ups which have caused on and off sinus congestion and pain. Unlike the typical allergic rhinitis sufferer, I typically do not have a runny nose or watery eyes, but rather I have sinus pain and post nasal drip. These symptoms results from a fairly common anatomical abnormality that causes my middle turbinate in my sinus cavity to actually develop an interior sinus of its own, called a concha bullosa. My case is more atypical since I actually developed symptoms from the enlarged turbinate as was revealed in a CT scan of my sinuses.

In all actuality, I almost never notice any symptoms of the concha bullosa, but when allergens catch me off guard, the little bit of swelling that does occur prevents proper drainage and causes sinus pressure and pain. Anti-histamines and nasal decongestants work quite well in prevention, but I want to avoid medication if at all possible. Additionally, your standard NSAIDs such as ibuprofen and naproxen work well to damping any pain that results.

The reason I am writing this post as of now is that today has been especially annoying since I did not take any medication and I have had on and off facial pressure throughout the day. I am pretty sure that as soon as I get home, I will take some form of anti-histamine. When the flare ups are especially bad, I begin to find it hard to concentrate or think critically. Some times I feels as if my vision on the right side (concha side) even blurs a bit when things are especially bad. I wonder if anyone else out there has any condition similar to this and has any advice. These conditions do not seem to be worsening, just only cropping up during allergy seasons...fall and spring.

Epic dinner, Bike fail

2010-03-17T20:43:00.004-05:00

My roommate and I decided to set out today for a biking excursion to South Congress today so that we could grab some grub from some of the trailer eateries for dinner. Before the journey, we decided to preform quick maintenance on our bikes. Each of us pumped up our tires to insure proper inflation. Once the bikes were all prepped, we departed!

The ride to South Congress was quick and fairly effortless other than the absurd amounts of traffic. Once downtown, the pedestrian and automobile traffic drastically increased. A couple of factors contributed to this fact... rush hour standard traffic in addition to the SXSW traffic. So many hipsters!!! The largest crowd of people by far was the line that wrapped clear around the Paramount Theater.

After a quick jaunt onto the sidewalk to literally walk faster than the buses, we were able to quickly make it up South Congress to a crepe trailer. Crepes Mille was pretty awesome and the savory crepe that I ordered really hit the spot. I got the pork chop chipotle crepe which was fantastic! The pork was cooked just right and was still nice and moist and the spices in the sauce on top were stupendous. Everything about this crepe was made of win!

The second stop was a grill trailer which I already forgot the name of! We got chili fries here which were also good! Soon after finishing up, we began the return journey. Unfortunately, the return ride is almost entirely up hill. To top everything off, as we started the ride back my tire began to flatten before my eyes. The grand finale of the awesome dinner run was a long defeated bus ride home due to a destroyed rear bike tire tube.

How to enjoy cheap wines

2010-03-03T23:49:00.005-06:00

One of my many interest that I like to cultivate when I have the time is my interest in wine. Note, I am also extremely interested in beer and have even brewed my own in the past, but I'll save my discussion on that libation for a later date. My interest in wine began fairly early and has spurred into an on an off hobby of sorts. Ultimately, one of my dream scenarios would be to retire to a vineyard and manage operation at some point in my life! However, this seems like only a dream and for all I know my opinion might very well change!

Rather than ramble on about how I cam to like wine and why I appreciate subtle complexities of the drink, I would rather talk about a simple way to improve most wines! As a graduate student, I live on a constrained budget and thus typically limit my spending on wine to less than $8 a bottle. Simple tricks improve the quality and enjoyability of even cheap wines.

A simple rule of thumb for wine temperatures:
1) Red wines - typically these wines would come directly from the cellar for serving. You want to cool a bottle of red for a brief time before consumption to replicate this cellar temperature which unlocks other aromas and flavors. Just 5-10 minutes in the refrigerator should do the trick!

2) White wines - although you want to serve your white much colder than reds, you do not want to chill them too long too! Rather than leaving a bottle in the refrigerator overnight, try chilling for two hours. This will bring the wine to a more appropriate temperature.

Keep in mind that cooling the wine too much is not the end of the world. Just allow the wine to slowly warm up in the glass as you consume, the flavors will emerge! These steps are extremely simple and radically improve even a $5 bottle of wine!

Qualms with Hypocrites

2010-02-24T21:40:00.003-06:00

The past year, I have increasingly noticed the depth and magnitude of hypocrisy in politics especially in DC. I am certain this force has remained ever present for decades and I have only become more aware recently due to my age and increased attention to politics. Despite that, there should be little tolerance of political hypocrisy in representative government.

I'm not talking about the personal hypocrisies, such as sex scandals and questions of character, smeared across the mainstream media. These personal hypocrisies often conflict blatantly with the politician's core ideals, but these aggressions tend to be of the private life and do not personally affect me. The more vicious hypocrisies I am referring to affect everyone in the country and are a disgrace to our political system.

When politicians are elected to office with grand promises, I often wonder how much of what he/she says for election vernacular only. Many officials get into office with national ambitions, and then narrowly focus on their personal district with "pork" spending to ensure reelection. While a representative needs to represent his/her constituents, they should not "bribe" them with government hand outs and national deception. I've already touched on this topic in Lifelong Politicians and their Effect.

Another recent problems that has arisen in the past months is the hypocrisy of certain politicians about what is socialist and what is not. Recently many politicians have spread horror stories of socialism resulting in corruption and mooching. However, they oddly tend to protect social security and medicare, both socialist programs. As I said before, some form of coverage (especially preventative) is needed. I will soon touch on the topic of why basic health care for everyone is essential and difficult to encourage in an unregulated free market.

Repercussions of the Second Law

2010-02-11T23:14:00.000-06:00

The topic of second law of thermodynamics formulates the basis for the concept of entropy which describes the amount of "disorder" in a system. In a closed system such as a wine glass on a table, the wine glass exists in a state of relatively low entropy or "disorder". The glass remains intact and the crystalline structure that composes the glass itself is an ordered composition. However, if the glass were to be bumped and fall, the shattering of the glass would rapidly change the glass from a state of low entropy to a state of high entropy or disorder.

The state of shattered glass represents a higher state of entropy since there exist many possible ways for the wine glass to shatter or break, but there is only one state of a single solid crystalline structure. In a similar manner, the entropy in the universe as a whole must increase over time. Although this might sound as if wine glasses would have to shatter randomly to satisfy this condition, the entropy can potentially remain constant for a given isolate system (like the wine glass). However, as a whole the planet and the universe tend toward disorder.

In the field of engineering, we often use the concept of entropy to assist in the modeling and design of thermodynamic systems. Such systems, such as a car engine or a power plant, have a physical peak efficiency which cannot be exceeded. This theoretical peak efficiency describes a device which does not generate any entropy. A perpetual motion machine on the other hand (which is not physically realizable) would actually generate negative entropy and have an efficiency greater than 100%.

The thermodynamic applications for engineering systems derive from the classical laws of thermodynamics. However, if you approach these laws using a different lens such as statistical thermodynamics, the concept of entropy can yield some unconventional results. Depending on the initial state of the universe, whether it be a low entropy state or high, radically alter the statistical probability of our existence now. This may seem daunting, so I'll saw the rest of this post for a later date!

Lifelong Politicians and their Effect on Modern Government

2010-02-03T00:08:00.001-06:00

One thing that bothers me about modern politicians is the tendency for most elected officials to be lifelong governmental members. Lifelong politicians are members of the elected body who remain in service for the majority of their life, continuously being reelected for the same or similar positions. Not only does this create governmental representatives that are more concerned about retaining office than governing, but also produces detached politicians that are more aware of DC than their constituents.

The framers of the constitution had reelection in mind when formulating the outlines of our government. The two houses of Congress have different election cycles: 2 years for the House and 6 years for the Senate. The framers also left the capability to be reelected in the constitution as well. However, the framers did not intend for lifelong politicians either. Citizens could be reelected a couple of times to serve their country and then return to their profession and home. This seems to make sense when you consider that most of early elected officials had professions on the side that they maintained while in office (be it medicine, law, agriculture, etc.).

Now with politicians worried about their job security much akin to everyone else, they become cautious and defensive. The Republicans have been hostile to any initiative put forward by the Democrats since Obama has come to office which at this point has potentially destroyed any chance of bipartisan cooperation. If a Republican begins to constructively engage in lawmaking with Democratic support after all the harsh words, their job could be at stake. Likewise, the Democrats have been biding their time on many issues, rather than making decisions. (Note: a lot of good has been accomplished. The bailouts among other things, although not visibly effective, are certainly what kept the country/world out of depression which would have put the unemployment rate even higher)

I am not for the creation of laws to prevent lifelong politicians, but I do feel that precedent should be established so that people would not feel “right” remaining in a position after more than a couple of terms, just like the presidency once was until the constitution was altered. Once this new culture of short term politicians becomes norm, I believe the country can truly show initiative and rejuvenate not only the government but the citizens that elect them.

Vacuum Fluorescent Display Tube Clock

2010-01-26T14:31:00.009-06:00

Recently I just completed the construction of my vacuum fluorescent display (VFD) tube clock which Stephanie gave me for Christmas. I was so excited when I found out that I would receive this from her, and I just couldn't wait to begin the construction. However, due to the popularity of the kit, the availability was initially limited so that the package did not arrive until well after Christmas. Patience is a virtue! (That really proved to be true with the ridiculous amount of soldering that had to be done!

Eventually after the kit was hand deliver by Stephanie :D , I was able to begin soldering the kit. Rather than use my desk at my apartment as a soldering surface, I relocated everything to my lab at the university. Everything just felt more scientific that way! After sorting through all the pieces and ensuring the the bill of material was fully at my disposal, I began the solder mess!

All in all, there were over a hundred solders that had to be secured. While not difficult, this just turned out to be a test of patience and steady hands! Fortunately, the printed circuit board was neatly laid out and even contained a surface layout grid indicating the component locations. No other solder job felt so secure!

After soldering the most ever in my life and struggling with all the VFD tube wires which had to be feed through individual holes, I completed the clock! I am very pleased with the results! Thanks again Stephanie! :D

Another semester awaits!

2010-01-19T20:59:00.002-06:00

Today was the first day of a new semester! My first thoughts as I biked into campus today were of the dramatic increase in the student population. The undergrads had returned again! Of course, at the beginning of every semester, the campus is excessively busy and the population dramatically decreases after the first couple of weeks. I like that part of the year!

I've got quite a load for this semester and that has nothing really to do with my courses. I'm taking a multi variable control theory course from which I am looking forward to learning a lot. Any course with "control theory" in the title is an attention grabber in my book. Other commitments involve paper writing, thesis writing, continuation of electric ship research, helping undergrad research, and ASEE. Whew, now I am afraid.

Actually, while this may seem daunting, I'm quite confident that I will get a lot accomplished! Hopefully, I will continue to update this blog as well! If I manage to update one more time this semester, even that might qualify as a record!

Thoughts on Education Reform

2010-01-05T20:19:00.003-06:00

Although America has one of the best university systems in the world, the quality of the primary and secondary school educations is a sad sight. Don't get me wrong, there are a lot of fantastic public schools in the country, but those lie primarily in the suburb areas of larger cities. Other schools across the country have an extremely difficult task of teaching kids that could care less about learning all while retaining the teachers in these much needed environments.

I know a few people that have decided to teach after going to university, and everything I hear from them about the school environment indicates that many students do not want to learn a vast majority of the current curriculum. In my eyes, this creates a huge problem. We have students that stigmatize learning, especially math and science, into something that is not worth their time. What this creates is apathetic citizens. We are spending money on a system that attempts to educates but fails. Again don't get me wrong, the system works for many people especially those people that ultimately end up at a university, but the system fails for many others. We should not pay for failure!

What I suggest is that over time a system more akin to Germany's primary and secondary educational system. At some point in a students career, a decision is made about what type of school the student wants to ultimately go to. There are trade school bound, potential trade school or university bound, or university bound. For the different students, there are different educational programs.

I think that a modified version of the German system could be highly effective here in the United States. Rather than a single university oriented curriculum, students could choose or be assigned to a specific curriculum track. These tracks would have to be flexible so that students could switch between them while they were younger (say middle school to early high school years) to allow for corrections for mistakes in curriculum choice. There could be many options for curriculum paths. Students that could care less about education could choose a more practical education to prep them for trade school (which they should be able to start early, so they can get into the workforce). Potential paths would provide a more personalized education.

Although a reform of this type would most certainly be a hefty investment, I feel the result would be a generally better informed public on many issues! I think we would produce many more graduates that would be much better prepared for their respective industry of choice as well as individuals that are more confident in education in general. Finally, we would produce students that do not stigmatize education and learning. Science and math in particular would not be view by many as horrors from high school but rather exciting classes from elementary school.

Issue to Discuss - Immigration

2010-01-01T11:08:00.003-06:00

I find myself often frustrated with the lack of mutual understanding in the United States between citizens and recent immigrants. One of the dominating features of this country since signing of the Constitution/ Bill of Rights has been the reliance on the steady influx of immigrants to make this country great. Nowadays, it seems as if more and more people are opposed to not only illegal immigration, but constricting totally immigration on legal immigrants. I have heard many radio shows and politicians proclaim that immigration leads to terrorism.

While immigrants could potential perform terrorist acts, there are already many citizens that terrorize this country with heinous acts (see serial killers or Timothy McVeigh) Immigrants are usually more interested in conducting what they came to the country to do, work. Of all the influx of immigrants, the goal of all but a very very small minority is to provide for themselves and their families, just like everyone else.

Unfortunately, immigration has always been a hotbed issue in any country that has any significant influx of citizens. The Europeans have been dealing with these issues for centuries, even with immigration amongst themselves. Even the original German immigrants to the United States were eyed with suspicion. Many of the British-Americans thought that the Germans would never integrate and would divide the country. Now nearly 3 of 4 people in the United States can trace some German heritage.

Even if a group is more slow to adopt a culture, the effects are not necessarily detrimental! Historically, societies that would adopt other cultural ideals always fared better than the resistive societies. Plus, adopting some aspects of new cultures is often rewarding (and delicious in the case of food!) After all, this country has always been known as a "melting pot".

To those that oppose immigration (especially if you oppose new legal immigrants that did everything the right way), you should think for a second on why you deny someone that happens to come from somewhere else the ability to become an American. The United States is a land of opportunity and people from around the world want a chance to experience the freedoms available here. Allow yourself to accept the fact that the "American dream" is a shared dream, and can only be had by anyone if we stamp out the greed and share.

Snowboarding!

2009-12-30T11:05:00.004-06:00

For the second time in my life, I went snowboarding! And the results from this snowboarding adventure were much better than the last. Last year, I skied a few times and then decided to try snowboarding a single time. Unfortunately for me, the snow was hard as ice on the day I decided to attempt and I fell square on my tailbone a few too many times. My butt hurt for a week after that potentially from damage to my coccyx.

However, this time around, the snow was fresh and they were in the process of creating more with the snow blowers. Additionally, we decided to night board since my brother and I had never tried that before. So once five o'clock came, we loaded up the car with our gear and my brother's new snowboard and hit the road.

Although the snow was ideal, the weather was harsh! There were frostbite warning signs everywhere and the wind was wiping up snow on and off all night! The first ride up the ski lift was especially bad. Neither of us had our goggles on and I didn't even have a mask. The snow was blinding and really stung as it whipped past the face.

Once we begun the snowboarding though, there was no turning back. Although I started off a bit rough, I have begun to improve significantly over my abilities last year. Perhaps when we go snowboarding again I can hit the blue slopes rather than sticking only to greens! We plan on going again tonight, so we'll see!

What happened to the time?

2009-12-16T18:25:00.000-06:00

Well, the fall semester has drawn to a close and I have yet to update my blog. I figure I should at least attempt to update this blog near the beginning and after the end of semesters when I feel the most fresh and relaxed! At this point, I can probably keep up with blogging fairly regularly over the break. If not, you can always follow my twitter: http://twitter.com/jonsage

For some reason, microblogging is easy to keep up with rather than posting once a week. I suppose it has to do with the simplicity and the fact that some updates really have no contribution to anything. Such as, “Detour to the campus computer store, need another copy of windows 7”, I could not imagine posting a blog entry about that! Typically I don’t tweet such mundane things though, so it might actually be worth following me!

Ugh, major twitter sidetrack there! Anyhow, my semester ended on a high note. I did quite well in my class this semester even though we did more proofs in three months that I have done in my entire life! This more theoretical approach to systems theory was a nice alternative approach to the applied stance that I am familiar with. Perhaps the theory will come in handy some day!

Another success of this semester has been my research progress. Although there were some major hurdles, I made some significant breakthroughs. I am pretty hopeful that over the winter break I can make some major progress on my master’s thesis!
I am super excited since Stephanie finished her finals today! She did really well and will be coming up to Austin tomorrow! We have a lot we want to do, so I will try to update about all the fun we have!

Engineers and Politics in the United States, Part II

2009-11-01T22:36:00.001-06:00

Engineering interest in political office has dwindled since the 70’s. The current professions that most politicians identify with are overwhelmingly law and business. While lawyers and businessmen are apt at making decisions on many diverse issues, the addition of an engineering perspective would introduce completely different assessments. Since engineers learn how to become effective problem solvers during their education, an engineering assessment might be more focused and logical. Engineers might introduce constraints on possibilities and could effectively produce requirements for potential legislative solutions.

As history and outcomes from other countries show, the involvement of engineers in government and politics has the ability to spur national interest in engineering beyond representation from corporate engineering firms with lobbyists. Corporate lobby groups tend to be interested in the welfare of the firm alone and not of the engineering profession as a whole. A side effect of a renewed national interest in science and engineering would potentially be an upturn in interest in math and science in primary school. The expansion in science and math interest from the public would stimulate public awareness of key issues such as global warming and limited natural resources.

Of course, engineers in congress and in politics generally are not going to solve problems alone. Continued involvement from a majority of engineers in the country in both politics and education are a necessity to maintain the profession as a whole. Science and engineering issues will affect the engineering profession over the next decade and proper representation is needed to ensure that the engineer’s voice is heard.

Engineers and Politics in the United States

2009-10-30T22:24:00.000-05:00

American society loves the by-products of science and engineering such as the latest gadget or the ample supply of low priced gasoline. Furthermore, there is not a day that goes by without the mentioning of health care, renewable energy or climate change on the media circus. With so much focus from the nation and the government on the products of engineers, the lack of strong local and national engineering representation is just short of alarming. Not only is legislation regarding engineers pushed through congress unbeknownst to most engineers, the lack of engineering representation does not provide national leadership with different engineering perspectives of problem solving.

Engineers in politics are not unheard of in the world. In fact, many other countries in the world have ample representation from the engineering community. In the People’s Republic of China, a significant portion of the government has engineering representatives including the president Hu Jintao, a hydraulics engineer. In Iran, President Mahmoud Ahmadinejad is a civil engineer. Engineering/scientist representation in the United States congress is minimal by comparison. As of 2009, less than ten representatives identify themselves as a scientist or engineer.

The disparity of engineering representation in politics has not always been such an issue in the United States. After the Second World War, representation was greater from the engineering/science community. Not only were there successful engineering political action groups, but also famous figures such as Robert Oppenheimer and Carl Sagan to spearhead the movement for engineering and science needs. As a result of these efforts, many engineering achievements such as the space program, interstate highways, and the electronics revolution were realized during this time period.

Thoughts on New Life

2009-10-28T01:29:00.001-05:00

You know what bothers me? Fundamentalist extreme anti-abortionists. The fact is abortions have been going one for essentially the duration of human history. If you look in any text about nearly all ancient societies, with the exception of the Egyptians oddly, you will find that these societies performed infanticide. I guess you could say that in those cases the fetus had moved beyond the third trimester but was “aborted”. I know that this practice is barbaric by modern standards, but my point is that people will want/need abortions not matter what the law says. Might as well make the process legal for most cases and regulate the procedure to minimize the risk.

The vast majority of people that have abortion procedures, especially the late term abortions, have the procedure due to health risks or due to irreversible developmental damage. Somehow there is this idea out there that people just get pregnant to have abortions. Or that they have sex not caring about giving birth knowing that an abortion clinic is just right around the corner.

The only reason stories like this ever occur is the lack of knowledge and education to kids about safe sex. We need to inform kids that of course abstinence is good to a point, but if things happen safe sex is the way to go. There are so many options for preventing unwanted pregnancies, that abortion of non-medical emergency fetuses should be a thing of the past. I wish I would see stronger support from the right for safe sex practice, which would solve so many problems and appease so many crazy fundamentalists!

I completely support pro-choice for the reason that no one should be subjected to pain or suffering that could be avoided. In the case of rape or health risks this should be obvious, but for some reason for so many the reasoning is not clear. (I also find it odd that those that support pro-life and denounce abortion as murder can also be so vehemently for the death penalty…which is more so murder, but that is for another post)

A Wavin' Flag

2009-10-16T00:46:00.001-05:00

Over the past couple of weeks, I have been listening to this new release by K’naan, called Wavin’ Flag. I think his story is inspiring. He was born in Mogadishu, Somalia, which for all intensive purposes has no centralized government. From this horrifying background, he was able to emigrate to Canada and produced music about the trials of his life and growing up.

I admit, I have been listening to this song several times over the past few weeks. I think the overall message resonates strongly within me. Rather than the standard message of a lot of popular music currently in America which is promoting a materialistic society, this song promotes just plain survival. In a sense, we are all in this life for survival. Some of us, myself included, are so very fortunate to be born in a first world country that we should pour efforts into making the world a better place, rather than polarizing our out society.

After listening to this song again, I just felt like making a little note on my blog about the need for people to empathize with others more so. Even though everyone comes from various backgrounds from different parts of the world, we are all human and feel the same emotions. Whether you believe it or not, we can all feel pain and suffering in a similar manner. Why spread the pain?

Why health care?

2009-10-14T16:59:00.002-05:00

With all the debate about the health care situation currently in the United States, I figure I would give my two cents on the justification for universal health care as a human right. I know the issue is complex and involve a multibillion dollar industry that spans many fields, so I cannot expect to solve the issue in a single post, let alone my lifetime! However, I do think that the idea of universal health care is justified for several reasons. With the correct policy and cooperation between insurers and health care providers, health care reform can happen within the next few years!

Some may claim by granting citizens universal health care to every citizen, we are decreasing the motivation for hard work due to the guarantee of health care. I think this viewpoint could not be further from the truth. The issue is that whether someone works hard and is motivated or not, typically health care is not the first item on the list for expenses. People want to make money for a slew of reasons but paying for large health care premiums is not one of them! My girlfriend, Stephanie, is in optometry school currently and tells me all the time how much people take their vision for granted. Not only do people take vision for granted, but they also want exams, medication and glasses for next to nothing. Hence, people in general want either free or extremely discounted (coupon mongers) health care services. However, if quality slips due to anything, the American consumer is voraciously demanding and will complain to no end. Something must be done!

Another aspect of health care is the notion that it is a privilege not a right. I have to disagree with that statement. If you are an American citizen, you are guaranteed many rights under the Constitution and famously from the Declaration of Independence that "all men are created equal." Of course, that quote must be taken in a sense that politically all men are created equal as everyone comes from a different background. Having a different origin with different views and ideologies can skew people into different directions. Additionally, people are not created equally in immune systems and risk of disease. No matter how hard one might work to prevent disease, there is always a possibility of sickness. Sickness can be completely random as well; a perfectly healthy individual can quickly succumb to cancer or an aneurysm.

Since sickness and disease can affect anyone indeterminately, it destroys the competition scale of capitalism in a way. Even the strongly motivated could succumb to disease and fall well behind both in career and in monetary standing. I wish that more Republicans would see health care in this light and they could seize the opportunity to forge change. In Taiwan, the conservative party essentially "stole" health care reform from the liberal party and now represents a majority. Something as essential as medical care should be guaranteed to all citizens of this country and I fully support health care reform to make this change.

Study time out of Austin

2009-10-12T21:50:00.004-05:00

After such an exciting Friday in Houston, Stephanie and I needed to crack down and actually begin out studies. We did manage to catch up on sleep over the night as well, which was much needed for both of us! The two of us prepared for a tough study session and then grabbed lunch over at Panera Bread where I was able to satisfy my cravings for the black bean soup and whole grain bread. Seriously an awesome combination.

After lunch, we settled down for studying at Minuti's coffee shop. This was the first time for us to visit and I must say that we were impressed. The service was great and the drinks were delicious. Since I am used to the caliber to the independent joints in Austin, I have to say that this place could compete. (I hope it kills a Starbucks) I got a mocha and Stephanie got an italian hot chocolate which is essentially hot chocolate pudding! We managed to study proficiently for about four solid hours. This was a relief for me due to the back log of work that I had!

That evening, we decided to try a different thai restaurant in Houston with some of Stephanie's cousins and her sister. The place, Nidda thai, was actually quite good. I got the drunken noodle which was a mix of noodles, chicken and veggies with a spicy sauce. Stephanie got a duck curry, which she unfortunately didn't like. The curry was milky with a mix of sweetness and spiciness which amounted to a creepy flavor.

Along with more studying on Sunday, this weekend was great for catching up on work and having an absolute blast with my Stephanie! I can't wait for another weekend like this or the weekend before!

Weekend Jaunt to Houston

2009-10-10T21:34:00.002-05:00

Even though I have a daunting systems exam this week, I made the three hour journey to Houston to visit Stephanie for the weekend. After spending some time in my lab preparing a review of information for the exam, I took off early at about 2pm to get on the road by 3. I ate a quick lunch at P. Terrys and picked up a bunch of cookies for Stephanie and her family, and I was out of town by 3:10.

Due to the cold front that came through, the sky was overcast and dreary for the entire drive. I encountered the occasional drizzle, but overall the drive was nice and smooth. By the time I arrived in Sugar Land, my stomach was informing me constantly of my hunger. I suppressed that need easily due to my excitement to see Stephanie. She was excited to see me once I arrived too! Since we were all hungry, we quickly left for Freebirds to get some dinner.

Freebirds was delicious. I packed my burrito with just about everything that could fit in a tortilla, including habanero sauce. Stephanie mistakenly asked for the "hottest" sauce, which implies habanero. She regretted that mistake a bit, as her burrito has some areas of intense burn!

After the dinner extravaganza, Stephanie and I went to see the movie "The Informant". That movie won out over Paranormal Activity by only a small margin, but I think we made a good choice. I really enjoyed the movies subtle comedy and just overall confusion of Mark Whitacre's story. Overall, I would rate the first day of this weekend as a great success!

Time at Torchy's

2009-10-08T22:52:00.000-05:00

As is our custom on Thrusday, I met with my friend Jesse from undergrad engineering over at Torchy’s Tacos for dinner. We rotate where we eat every week, but my stomach indicated an urge for the Torch. I should note that the Guadalupe location parking lot is located right off the street which can cause many difficulties in both parking and leaving. Jesse was nearly victim to a three car pile-up when some idiot tried to turn maniacally across the street. Needless to say, I think I will bike there from now on!

Anyhow, we were slightly disappointed as we anticipated the October taco of the month sign would advertise a delicious new taco, but apparently they did not feel like coming up with a taco. I wasn’t too disappointed though since essentially all of their tacos are amazingly delicious. (If you have not been to Torchy’s yet, please take leave of this post and go eat some right away!) I went with one of my mainstay tacos, the trailer park, and one of the more “mysterious” taco, the fried avocado. Also since my lunch was miniscule, I ordered some queso to tide me over. My stomach was caving in on itself by dinner time!

Jesse has been persistently trying to persuade me to eat the baja shrimp taco nearly every time we go. One of these days, I will definitely get the taco but I guess I have to be in the right mood, haha. Overall, I have to say that Torchy’s is near the top of my rankings of Austin eateries. Other than minor issues of parking and limited seating, the service and food is top notch for a good price!

Another blog return

2009-10-07T19:39:00.004-05:00

The vicious cycle of my blogging habits astounds me sometimes. I managed to post fairly regular updates over the summer which for me is pretty amazing. Then Stephanie and I took our trip to Europe and the entire cycle of posting collapsed like a Ponzi scheme! (By the way, the trip was incredible, and Stephanie and I had a ton of fun. I'll have to post about it soon) I will attempt again to update at the very least weekly, but who knows how long that will truly last!

As of lately, I have been pretty consumed with my research. Though, I admit that I am not so overworked that I couldn't post a blog entry once a week. That is due to laziness. Anyways, all this effort into my research has paid off and I will have papers in two conferences and also possibly a third! I am pretty excited about these publications.

Another interesting side note is that I finally finished my personal academic website which I have been working on for a little while. If you are interested you can find the site here:

https://webspace.utexas.edu/jrl462/

Check it out and let me know what you think! I am always open to suggestions. Hopefully there will be another more real blog post soon. I will add a deadline to my calendar...maybe that will encourage me.

Productive yet Exciting Day

2009-07-22T22:16:00.002-05:00

As a weekday, I usually feel inclined to spend the majority of my day working on research, especially since I will be in Europe for two weeks. I have been trying hard to gain a surplus on my research so as to relax and not worry while enjoying myself over seas. Today, however, I accomplished both work and leisure.

I had an early start to this morning and spent the bulk of my time on research. The vast majority of my time was spent on my matlab code which calculates the transmission matrices of any given system formulated in bond graph terms. The code then performs impedance synthesis to produce a desired frequency response. All quite fun!

After a reasonable amount of time devoted to research, Stephanie suggested that we go on a bike ride. Of course, I found this idea extremely captivating. Time spent on my bike with Stephanie is time well spent! We decided to venture from my apartment to the snow cone/lemonade stand near Barton Springs.

The path we took runs directly along Shoal Creek, from 38th street to Town Lake. Even though today was slight overcast, midway through the trek, the sun beat down on us. Needless to say, Stephanie was not too keen about the head. Eventually we did make it to enjoy out sour apple snow cone and lemonade.

To top it all off, we took a ride on the Zilker Zypher, the small train that circumnavigates the park. Other than a few hop ons which cause the train to have to stop, the ride was fun. I have not waved at that many people in quite some time! Although the return ride was all up hill, the bike ride was totally worth it.

American Political Parties - My Take

2009-07-19T16:03:00.008-05:00

One of the most frustrating aspects of modern American politics to me is the polarization of parties in the two party system. If the Democrats support pro-choice, you can sure be that the Republicans take the opposite stance. I know there are always dissenters of opinion in each party, but these dissenters are always in the minority.

I feel that the lack of diverse parties often snuffs out the moderate opinions and puts forth the more extreme and partisan ideas. Not only does this breed hostility between parties, but also between American citizens. With a polarized political system, many people debate as if they are either on the left or on the right, with all the defining features of the corresponding tag.

The idea of the "red" state and "blue" state is extremely polarizing as well. Not only is the political scene altered, but the cultural norms may change as well. Again, the trouble becomes the difference between "us" and "them". If politics became more moderate overall, maybe this attitude would dwindle away.

Many other democracies have multiparty systems, such as all the European parliamentary governments. These systems of government often encounter quagmires of stale voting due to the lack of collaboration between the five or so parties in power. I strongly advocate against a system of government like this, as the bureaucracy that four or more parties can cause is frightening. What I advocate is a strong third party.

What can come of a strong third party you may ask? Well, when third parties played major roles in elections such as with Ross Perot in 1992 and 1996, many of the debates shifted toward very moderate stances from all parties. I believe that if a major third party were to ever rise, the country as a whole would be in a better state. Rather than voting for one extreme or the other, the playing field would be leveled and all parties would become more moderate to attract potential voters.

With the Republican party sharply divided between the Limbaugh nutcases and the conservative businessmen, perhaps a third party is viable. I guess the Libertarian party could be viable too, but they need to moderate some of their stances if they ever want to hold higher offices.

Hamilton Pool - A swimming adventure

2009-07-17T22:24:00.001-05:00

Today was quite a fun adventure. As had been planned for a week, I went to Hamilton pool with Stephanie, Kayla and Steph. What made this especially fun is my love of swimming and the unique location. I have swam in many natural springs before, but this one is by far the most unique. If the reader is unfamiliar with Hamilton pool, the swimming hole is a natural spring pool surrounded by an outcrop cave structure.

We woke up fairly early to set out for the pool, since the drive there took about thirty minutes. Another reason for heading out early is that the operators of the pool limit the parking to 75 cars. Once the lot is full, the pool is essentially closed until someone decides to head out.

After arriving, we took the quarter of a mile hike to the pool which is tucked away in the nearby forest. Due to the spring water, the aired landscape surrounding the spring transformed into an almost marsh-like environment. At a certain point, we could here hearty laughter and cheering and at that point we knew the pool was right around the bend.

The swimming hole was a lot of fun and many people were there to enjoy the sun and swimming. Unlike Barton Springs, the pool is not significantly below ambient temperature so it feels more like a normal pool. Normal is relative though since there are tons of little rocks that are pretty harsh on tender feet. Stephanie had some trouble getting in and out of the water due to the sharp nature of the rocks!

After swimming for a few hours, we decided to head out. On the return journey, we unanimously decided that Sonic happy hour would top the day off. The cherry limeade was a great peak in the day!

Europa Universalis Series - My Thoughts

2009-07-14T22:16:00.005-05:00

One of the video games that I would call my favorite is the Europa Universalis series by Paradox Entertainment. I have enjoyed this series for years and started with the first game in early high school. Although the graphics of Europa Universalis are not striking (looking like a glorified Risk board), the depth of the game is captivating. The beauty of these games is that you can play as any country in the world at any time period from the medieval times up until right after the French revolution.

I have to admit that another personal draw towards these games is the shear depth of the game play. As the leader of the nation, you have control over the government, the military, the economy, external trade, research, and colonizations among other things. You must ensure the stability of your nation, the reputation of the nation amongst the neighbors, and ensure that you do not go broke due to low taxes.

Another interesting tidbit about this game series is that there is no ultimate goal. There is a degree of flexibility and creativity that goes with this game. If you are playing as France, you "victory" condition can be to fully conquer your long time enemies, the English! Or if you are playing as the Incas, you can attempt to colonize all of South America before the Europeans (or someone else) reaches the new world.

Although there are historical events that can shape the outcome of the game, overall the games can be quite unhistorical. I have had games where Venice has large colonial assets in North America! One could only imagine the historical consequences of a Doge controlling aspects of American life!!

Needless to say as a fan of history, this game keeps me entertained with both the sprinkling of historical facts as well as the shear hilarity of the results sometimes. I highly recommend Europa Universalis III with the expansions to any fans of history!

Qualms with End Time Beliefs

2009-07-12T21:55:00.002-05:00

One of the most perturbing aspects of all the world’s major religions is the belief in an end of times or armageddon. While many people would argue that this belief is harmless and worthy of preaching due to the implications of a “judgment” on their life, I completely disagree. All the major religions with belief in an afterlife have a form of judgment occurring during the end times. Although the initial goal of this teaching is to bewilder people into proper and moral behavior, I think in many ways that the belief in the end times encourages reckless behavior.

How can a belief that motivates moral behavior for admittance to the afterlife cause problems at all? If you give this question a little thought, several things may jump to mind. First of all, if admittance to the afterlife is a tedious process and only granted to the most devout, why bother with religion at all. Unless you are the most pious person you know, then you are screwed and well, that leads to quite a dilemma. I will touch on the fact that religion and morals are mutually exclusive in another post, which this first qualm with the end days touches on.

Secondly, if one feels there is a chance for admittance during the end times, there is a possibility that religion is put before everything else. I am sorry if some are offended, but personal health, the environment, family, humanity, and preserving our future all outrank religion in my book. (Spirituality, on the other hand is a different matter…in this sense I refer to it as being in touch with your inner self) I hate to think of all the relationships out there that are destroyed due to the devotion to a religion that ultimately is joined for improving life.

A final point that I want to make is that the belief in end days destroys the need to put the future as a priority. If the world will be destroyed at some point, then why care about the environment or world peace. In fact, I know that some out there feel that armageddon will be brought about by human activities. That is a frightening thought as it can be fully prevented!

I ask all of the members of religions with end times beliefs to question and keep an open mind. Humans will go extinct at some point; it is a certainty as the universe will ultimately end too. The true tragedy will be extinction by our own hands, especially if we could have prevented the entire atrocity.