Fiddling with CGI to really understand how it works, I hit an annoying problem. It is not with CGI but with Elvis.

When preparing for my oral exam on the subject of Data Structure in the final year of my undergraduate study two years ago, I got the interest to perform an in-depth analysis on the different sorting algorithms presented on Schaum's Outline of Data Structures with C++, which was the textbook for the course, to really see how the sorting algorithms differ.

One frustrating point that I encountered twice during my course in using JavaScript is that a dynamic modification of a table leaves traces on the screen like missing background color. Googling for the solution was not that easy. But, at the end I found this good forum thread: http://www.dynamicdrive.com/forums/showthread.php?t=25139. Basically, you need to repaint the element yourself.

Before I worked on the service publishing AP project and having the course in massively distributed systems, I had never taken JavaScript seriously. In fact, I always tried to omit the use of JavaScript whenever possible preferring heavy UI interaction with the server (i.e., the server manages every single button that the user clicks) because each browser has its own quirks and it breaks accessibility. Moreover, the language is pretty much lenient unlike C so that combined with the quirks, I really didn't like to do JavaScript programming. And, I had the sense of insecurity in using JavaScript because it could be modified by a malicious user to send invalid data. But, through the project, I came to appreciate the use of JavaScript.

Having a programming project for a service publishing wireless access point running OpenWRT Kamikaze 8.09.1 in which I decide to use sqlite3 as the data backend, my first attempt in cross-compiling and running the service inquiry handler daemon that was fully tested on my laptop was greeted with a hang.

Throughout my undergraduate study, I only heard about Functional Programming but had never been deep inside it. Then, I had the chance to dive into it for one semester at RWTH Aachen: http://verify.rwth-aachen.de/fp09/. In short, the course was totally fun to get to know Functional Programming! Moreover, it improved my mathematical proficiency as well :-)

Source:
(1) Knowledge Representation and Reasoning by Ronald Brachman and Hector Levesque
(2) Artificial Intelligence: A Modern Approach (2nd Edition) by Stuart Russell and Peter Norvig

As a final assignment in my Languages for Scientific Computing class, I develop a Razz Simulator (http://github.com/eus/razz_simulation). Basically Razz is the inverse of Poker in which you try to come up with the worst hand (http://en.wikipedia.org/wiki/Razz_(poker)). The game is well explained in the slide for the first and second lectures and in the sixth assignment foud in http://www.cs.utexas.edu/users/pauldj/lectures.html. The first problem on Razz was at the end of the first assignment: given A, 2 and 3 to start with, what is the probability of getting a hand with rank exactly 7? Well, no one answered that correctly until the professor showed an elaborate calculation in Mathematica that resulted in 0.143008. One important message is that people don't do such an elaborate calculation in reality. Rather they use a simulation (i.e., play as many Razz games as possible with the given starting cards and count the number of times you score 7). So, the last assignment is about developing the simulator that can simulates as many games as possible in the shortest time possible. The most interesting thing about the assignment is that the program is neat enough to show some interesting software engineering principles in action beside telling you that Razz is not as simple as it seems to be.

Last week I got a question that asks me to show that the following statement about Y combinator (http://en.wikipedia.org/wiki/Fixed_point_combinator#Y_combinator) in LaTeX is correct:

Y z \leftrightarrow^{*}_{\beta} z (Y z)

where \leftrightarrow{\beta} = \rightarrow{\beta} \bigcup \leftarrow{\beta}

Last Friday the morning session of my Languages for Scientific Computing class was about Makefile. Well, largely there was nothing interesting since I know how Makefile works already. But, still the teaching assistant could surprise me with: make mrproper.

The other day a friend of mine asked me to code a decimal-to-hex-converter in MASM using DOS ISRs (Interrupt Service Routine) for I/O. Well, I just gave her the equivalent C code since I am not into proprietary software. But, anyway I googled for some materials related to MASM syntax and DOS ISRs for I/O [0]. Upon reading some examples of using DOS ISR 21h, I stumbled upon the use of LEA dx, var and MOV dx, OFFSET var. So, I decide to have a look into them and come up with the following conclusion.

I've bought a LED head light some time ago. Battery turned to be absolutely useless. It runs only 15 minutes instead of 12 hours. It has two holes inside, but there’s no liquid. Maybe all went off, and thus there’s no power… Even if had something, I don’t know what to put there, acid, alkali, water?..

Recently discovered, that it is possible to monitor "Smart Array" controllers under solaris 10 OS. You need to install HPQacucli solaris package, which can be downloaded from hp.com site, read carefully "RELEASE NOTES" about support of your server hardware and controllers, also make sure that you have a recent version of CPQary3 driver installed (2.1.0 or later). Here's an example output:

Free software does not mean public distribution. Free software means that the licensees have all of the four essential freedoms (http://www.fsf.org/licensing/essays/free-sw.html) with the software. Selling free software means that you license the software with a fee to a buyer under a free software license.

About some weeks ago I got the chance to fiddle with Android (http://www.android.com) that is used in mobile service discovery research in Mobile Communication System Engineering Lab (http://ds.informatik.rwth-aachen.de/teaching/ws0910/mcse/). The assignment was to create a simple ToDo list (http://github.com/eus/android_todo). But, it turned out that programming Android's ListActivity to highlight a ToDo item was not that simple.