A bit more then only studies

It’s been ages since the time when I posted something. Well “blog, blog, blog it all” its not my mantra. Anyway let start it all…

Studies – Background

As I written some time ago, I’m studying Computer Science and Mathematics. It’s a degree program that after 3 years I could be bachelor of Computer Science and then after 4th bachelor of Mathematics.

So why I choose that kind of studies? Computer Science was an obvious choice. Programming is in my blood and for me it’s something more than just a profession or a way of career. I write a first program when I was about seven, but I really pick it up when I was at 14 when I learned how to code in Pascal. I spend many hours studying mainly algorithms, linux system¹ and network protocols. Soon², I knew that it is what I loved to do. Mathematics is a different story. It learn me how to think effectively, solve problems and it’s sometime useful. I also put a lot of effort in it, but it wasn’t and it isn’t my aim itself. I like it, I was pretty skilled at it (at school level), but nothing more then that. So I list potential interesting studies for me:

• Warsaw University – Mathematics and Computer Science
• Warsaw University – Computer Science
• Wrocław University – Computer Science
• A few other options

I generally have a very simple criteria. Will it learn me something useful/interesting? Is it ambitious enough? So I excluded all universities that will force me to learn C language, that I already know. I also want to be taught things that I can’t learn myself, not only how to use XYZ library in ABC language. After that step most of universities of technology were out. Then it came the list above, which comes down to dilemma: do I want to one of the best in new university or be normal, but rather study among the most talented. When I want to be best, Cracow or Wrocław University were a good choice. Only a few students have probably similar achievements³. In other hand, to get into special degree program on Warsaw University⁴, finalist/laureate in Olympiad is just a requirement. There is about 30-40 students a year on that field, so it is a truly top level. It want to get out of studies as much as I can, so I decided to choose Warsaw University with its ambitious degree program.

Studies – real life

As I expected, hard work. I’ve got only four subjects, but quite a few lectures and classes in general. I give a few words about each of it:

Introduction to programming (functional approach)

It is an alternative subject who already know how to code and think in “normal” language like Pascal, C or C++. Instead of those well known language we learn ocaml. To give you a little bit of taste, imagine a language without a loops⁵ and variables, it’s how we mainly work. Because I’m already familiar to programming its relative the easy subject.

Mathematical analysis

A tough one. A lot of proofs, formulas and problems. In most cases if you think that something is obvious, it means that you don’t understand that.

Linear algebra and geometry

Less hard then analysis, but involves much more computations.

Foundations of Mathematics

Mostly logic, set theory, relations etc. Seems to be quite a nice subject, but I gave me final word after exams.

More then studies

Some of my activities: I regularly attend SKMA⁶ meetings. Plus some algorithm competitions just for fun. I also had to finished quite a few additional task related to my last internship job in ICM. By the way, I’ve coded a PHP back end, and translate image files design to HTML layout for a small website…

More to come on this blog

• A trip to Cracow.
• A series about some kind of programing tricks, first one about C/C++

1. I mean bash, commands, configuration, rather then exactly hacking linux kernel. [back]
2. In matters of years. [back]
3. I talk about algorithm competitions, were such a comparisons are possible. (mostly Olimpiad in Informatics) [back]
4. Jednoczesne Studia Informatyczno Matematyczne (translation: Simultaneously Studies of Computer Science and Mathematics href=”#fn1196968805184″>back]
5. and ugly gotos ;-). [back]
6. a catholic student organization [back]

After the exams

(this post was posted with a long delay (2 months); note that some of the time references might be broken )

This month I took several exams at the end of a high school. They are known as “Matura”¹ exams. This article aims to describe to foreigners (non-Polish) how they look like.

Polish education system²

Although, There are a few possible ways in pre-university education, one of it is followed by the vast majority. Most of Polish child start formal education with the age of seven and attend to three types of school:

• Primary school; 6 years; obligatory; Polish name “Podstaw�wka”
• Secondary school; 3 year; obligatory; Polish name “Gimnazjum”; often mistranslated as Gymnasium
• High school; 3 year; non-obligatory; Polish name “Szkoła Średnia”

Each of this school ends with a final exam, the most important one is that after high school because depending on its result you may or may not be enrolled to a state university. In Poland state universities are consider to be better than private ones³. Mainly because in order to get into a state university one need to have a really good results from your exams, in private ones just paying an entrance fee is enough in most of the cases.

Preparation to the “Matura” exams

Several months before high school final exams each student could⁴ choose which subjects is going to take on the following exam. The obligatory ones is Polish language (oral & written), foreign language (oral & written) and one other subject (written only). Each of this part of the exam could be selected on two different level of advance. Students could also take some additional subjects, however any additional subject could be chosen only on more advanced level. Personally, I decided to take following exams:

• Polish language – basic
• English language – advanced
• Mathematics – advanced
• Computer science – advanced

I don’t have to write computer science exam because of achieving a laureate in Olympiad in Informatics. I get maximum points from it. It’s a rare situation.

Most of the high school students choose a set of subjects that are required by university where they are planning to apply. Some of them also attend additional lessons and courses which prepare them for the exams.

The exam itself

Exam usually take place in May. Expect the oral ones, the date of the exams is fixed in whole country. All students are answering the same set of the questions and are graded within the same rules. The exam last from 1 to about 3 hours. Only a few of the exams are divided into modules. The exam difficulty usually vary over the years. However as long as you are well prepared there is nothing to worry. If you aren’t, the result is a matter of luck.

From my personal experience, not only raw knowledge and skills is important. Some of the exam aspects like knowing how to do your work in time, transfer knowledge to paper or how to find mistakes quickly are crucial. One of the helpful exercise is to write exams from the previous years in the similar conditions. The another good advice is to not study in a few days before the exam. Concentration is much more needed then a few more training (as long as you are already well prepared).

The results

Exam:	Part:	Result:	Statistics:
Polish language basic	oral	100%	11% of candidates score 100% points
	written	67%	23% of candidates score above 63%
English language advanced	oral	95%	12% of candidates score 95%, 11% score 100% points
	written	84%	23% score 79% or higher, note that most of the candidates take basic level(~ 83%)
Mathematics advanced	written	98%	4% of candidates score above 90%
Computer Science advanced	written and pratice	100%	4% of candidates score above 85%

⁵

I’m really proud of my Maths result, but English one shows that I still not good enough in English grammar (that is were I lose the a lot of points). Anyway, the result are really good, so I was able to publish them, without being ashamed.

1. the name “matura” came from Latin, like English word “mature” [back]
2. by the year 2007 [back]
3. with a few exceptions [back]
4. it isn’t obligatory, but almost all high school students decide to take this exam [back]
5. Statistics source: CKE [back]

Audio books – first impression

A few weeks ago, I have heard about audio books and their popularity. For me the idea seems somewhat strange. I’ve been used to reading a book for ages and, at first, I haven’t seen any reasons for giving it a try. Most of books were “designed” for paper medium, so putting it in sound may give strange results. For example, some philosophical disputes require more time to think then trivial conversations. Because the reader usually recite with constant speed, listener have the same amount of time to process text regardless its content.

On the other hand, I love to listen some kinds of radio broadcast services. My favourite ones are BBC programmes. So maybe other voice pieces could also be interesting. Anyway, Having little to lose¹ and a lot to gain², I decided to give it a whirl.

(e)Shopping

Happily, Polish e-shops with audio books already exist. Despite offering only a small subset of books, I found one that I would like to read. The audio books are available as simple MP3 files. It was a pleasant surprise for me, because I suppose to have them in semi-functional format with DRM. Within usage of my bank account I was able to download them soon after after making a transfer.

Hearing

Thanks to MP3 format, I copied audio book into my portable player. My first reaction after pressing “play” was “It’s different”. Listening a book is like going to the same place at nights. Trees, buildings, sites etc. are the same, but the general impression is other. The same is with audio books. The voice emphasise things which reader could easily miss and vice verse.

Conclusion

If you are still wondering whether audio books are worth hearing, you should definitely try them. They are especially handy when conducting or just waiting for someone. Within them, anyone could increase the number of read/heard books without too much effort.

1. time + a few $ [back]
2. find a new interesting thing [back]

Debugging printing – CUPS

Some time ago I noticed that printing works somewhat strange on my desktop. It ran smoothly in most of the cases, but rarely it refuse to produce output. The really weird thing is that I didn’t know why it behaved in such a strange manner. As it is stated Murphy’s laws, it seem to fail when I was in a time-pressure situations. “Luckily”, One day, when my printer produced an error instead of doing its job, I had a time to solve the problem.

Analysis – user part

First of all, I needed to work out what is the real problem. I tried printing a few different documents. I selected those problematic and checked whether they are printable with other programs or configuration. The basic rules are:

1. Repeatability and reproducibility – in what kind of situation does problem occur? Am I able to reproduce errors within doing the same steps? Does the problem repeat while using certain applications or it is document/configuration specific?
2. Isolation – what kind of programs are involved? Pinpoint all of the programs and configuration files that could cause the problem.

My answers to this questions:

1. Repeatability and reproducibility – the problem seems to be document specific. I found that it occur only within a small number of PDF and ps files.
2. Isolation – printing program related to CUPS such as ghostscript, pnm2ppa, foomatic and CUPS itself.

Analysis – debugging

At first I looked up for logs (“/var/log/cups/error_log”). It wasn’t useful at all, however It suggested turning on the debugging mode. So I look into CUPS config (“/etc/cups/cupsd.conf”) and changed LogLevel to debug.
[code lang="bash"]
#LogLevel info
LogLevel debug
[/code]
I tried printing one of those baffling documents. I looked at errors and saw:
[code lang="bash"]
(...)
D [17/Apr/2007:22:15:56 +0200] [Job 151] GPL Ghostscript 8.54 (2006-05-17)
D [17/Apr/2007:22:15:56 +0200] [Job 151] Copyright (C) 2006 artofcode LLC, Benicia, CA. All rights reserved.
D [17/Apr/2007:22:15:56 +0200] [Job 151] This software comes with NO WARRANTY: see the file PUBLIC for details.
D [17/Apr/2007:22:15:56 +0200] [Job 151]
D [17/Apr/2007:22:15:56 +0200] [Job 151] Closing renderer
D [17/Apr/2007:22:15:56 +0200] [Job 151] Error: /VMerror in --stringwidth--
(...)
[/code]
So it is definitely a ghostscript error. I googled VMerror and found that it is a postscript error which means that my RIP (ghostscript in this case) doesn’t have enough memory. Because I have a lot of free RAM, it is probably a bug of ghostcript.

Solution

I simple searched for ghostscript alternatives in the portrage(“eix ghostscript”). I decided to switch from “ghostscript-GPL” to “ghostscript-esp” so I entered:
[code lang="bash"]
emerge --unmerge app-text/ghostscript-GPL
emerge app-text/ghostscript-esp
/etc/init.d/cups restart # restarting cups service
[/code]
After these steps printing services work properly.