Archive for category Education
All Shall Be Well
Posted by Manfredas Zabarauskas in Education, Life on October 22nd, 2011
You step in the stream,
But the water has moved on.
This page is not here.
-- Internet Folkore
Rather surprisingly even for me, it has already been over five months since my last post. Writing a thorough and yet succinct account about everything that happened over that time is way beyond my literary abilities, so here's a bullet-point summary about a few things worth mentioning from that period.
1. Cambridge CST Part IB Exams Jennings Prize '11
Back in June 2012, folks at Computer Science Tripos Part IB (including me) had the opportunity to enjoy four consecutive days of exams. The structure of papers was straightforward: three hours, nine questions (one or two questions per course); five questions had to be answered.
If I could give a single advice to someone who is about to go through this process, it would be "time". Three hours will not be enough to answer five questions, and there will be almost no time to think about anything if you get stuck. Most likely, the bottleneck in your answers will be the speed of your writing, so don't make a huge mistake by thinking that you will be able to do less revision and figure out things "on the spot". You won't.
At the end of the day, of course, it's not the grades that matter, but... receiving the thing on the left was still nice.
2. Internship at Microsoft
My office at Microsoft (Redmond, WA, 2011)
Over the summer, I was working as a Software Development Engineer in Test in Microsoft Office team. In particular, I was writing a performance testing suite for the feature that is used across Office and Windows divisions when developing and updating over 50k+ pages of documentation on MSDN.
Microsoft Campus
Customized Xbox
Also, the perks that you get as an intern are incredible: paid flights, subsidized housing, free bike, two weeks of free rental car, gym plan (and if you're around Redmond, WA area - check out the Pro Sports Club). That, and all-you-can-drink soda at work! (OK, so you don't get free food as in some other places, but trust me, you will able to afford food from your intern compensation package).
Seattle Skyline, WA, 2011 Vancouver, BC, Canada
However, to make things even better, I have already received an offer for the summer of 2012! If there aren't any major changes, there is a good chance that I will spend my next summer working as a Program Manager intern at Microsoft Office team!
Microsoft Campus (Redmond, WA, 2011)
3. Vacation
This year me and Ada have decided to go to Turkey. We have spent two final weeks of September in a beautiful Alanya region: the weather (every single day above 30°C/86°F) justified the nickname of the region ("Where The Sun Smiles") and the Mediterranean Sea was simply magnificent. We were also very lucky with the choice of the hotel: two pools, five minutes away from the sea, extremely polite and courteous staff, and great all inclusive food and drinks!
Anyway, a picture is worth more than a thousand words, so here's a few of them. Enjoy!
P.S. Fact: it is possible to get a 500% discount when buying a leather jacket in Turkey. Verified. And it takes only a little bit over two hours of negotiating.
Backpropagation Tutorial
Posted by Manfredas Zabarauskas in Development, Education on April 18th, 2011
The PhD thesis of Paul J. Werbos at Harvard in 1974 described backpropagation as a method of teaching feed-forward artificial neural networks (ANNs). In the words of Wikipedia, it lead to a "rennaisance" in the ANN research in 1980s.
As we will see later, it is an extremely straightforward technique, yet most of the tutorials online seem to skip a fair amount of details. Here's a simple (yet still thorough and mathematical) tutorial of how backpropagation works from the ground-up; together with a couple of example applets. Feel free to play with them (and watch the videos) to get a better understanding of the methods described below!
Training a single perceptron (linear classifier) Training a multilayer neural network
1. Background
To start with, imagine that you have gathered some empirical data relevant to the situation that you are trying to predict - be it fluctuations in the stock market, chances that a tumour is benign, likelihood that the picture that you are seeing is a face or (like in the applets above) the coordinates of red and blue points.
We will call this data training examples and we will describe th training example as a tuple , where is a vector of inputs and is the observed output.
Ideally, our neural network should output when given as an input. In case that does not always happen, let's define the error measure as a simple squared distance between the actual observed output and the prediction of the neural network: , where is the output of the network.
2. Perceptrons (building-blocks)
The simplest classifiers out of which we will build our neural network are perceptrons (fancy name thanks to Frank Rosenblatt). In reality, a perceptron is a plain-vanilla linear classifier which takes a number of inputs , scales them using some weights , adds them all up (together with some bias ) and feeds everything through an activation function .
A picture is worth a thousand equations:
Perceptron (linear classifier)
To slightly simplify the equations, define and . Then the behaviour of the perceptron can be described as , where and .
To complete our definition, here are a few examples of typical activation functions:
- sigmoid: ,
- hyperbolic tangent: ,
- plain linear and so on.
Now we can finally start building neural networks. Read the rest of this entry »
Halfway There
Posted by Manfredas Zabarauskas in Development, Education, Life on April 12th, 2011
Another term in Cambridge has gone by - four out of nine to go. In the meantime, here's a quick update of what I've been up to in the past few months.
1. Microsoft internship
Redmond, WA, 2011
In January I had the opportunity to visit Microsoft's headquarters in Redmond, WA, to interview for the Software Development Engineer in Test intern position in the Office team. In short - a great trip, in every aspect.
I left London Heathrow on January 11th, 2:20 PM and landed in Seattle Tacoma at 4:10 PM (I suspect that there might have been a few time zones in between those two points). I arrived in Mariott Redmond roughly an hour later, which meant that because of my anti-jetlag technique ("do not go to bed until 10-11 PM in the new timezone no matter what") I had a few hours to kill. Ample time to unpack, grab a dinner in Mariott's restaurant and go for a short stroll around Redmond before going to sleep.
On the next day I had four interviews arranged. The interviews themselves were absolutely stress-free, it felt more like a chance to meet and have a chat with some properly smart (and down-to-earth) folks. Top of the Space Needle. Seattle, WA, 2011
My trip ended with a quick visit to Seattle on the next day: a few pictures of the Space Needle, a cup of Seattle's Best Coffee and there I was on my flight back to London, having spent $0.00 (yeap, Microsoft paid for everything - flights, hotel, meals, taxis, etc). Even so, the best thing about Microsoft definitely seemed to be the people working there; since I have received and accepted the offer, we'll see if my opinion remains unchanged after this summer!
2. Lent term v2.0
TrueMobileCoverage group project
Well, things are still picking up the speed. Seven courses with twenty-eight supervisions in under two months, plus managing a group project (crowd-sourcing mobile network signal strength, the link is on the left), a few basketball practices each week on top of that and you'll see a reason why this blog has not been updated for a couple of months.
It's not all doom and gloom, of course. Courses themselves are great, lecturers make some decently convoluted material understandable in minutes and an occasional formal hall (e.g. below) also helps.
All in all, my opinion, that Cambridge provides a great opportunity to learn a huge amount of material in a very short timeframe, remains unchanged.
There will be more to come about some cool things that I've learnt in separate posts, but now speaking of learning - it's revision time... :-)
Me and Ada at the CompSci formal. Cambridge, England, 2011
CST Part 1A
Posted by Manfredas Zabarauskas in Education on October 9th, 2010
... otherwise known as Part 1A of Computer Science Tripos in University of Cambridge has officially ended.
All in all, a rather enjoyable year. From the introduction to ML by the brilliant Prof. Larry Paulson, to the realms of Discrete Mathematics II (with a wicked a proof of existance of ordinal numbers in the exam); from Algorithms to Software Design, from Digital Electronics to Operating Systems, from Floating-Point Computation to Regular Languages and Finite Automata; and everything in between.
A crash course, but the one that is definitely worth going through.
If you're just about to come to Cambridge (or just starting your part 1A), here are a few simple tips that proved to be helpful for me:
- Don't fall behind - in lectures, ticks, homeworks, supervision assignments - in Cambridge pace it's difficult to catch up.
- Do things in advance - it's usually a very good idea and pays off well.
- Make sure that you keep your work/life balance: do a bit of sports (many choices in University of Cambridge Societies website) and go out once in a while. Paradoxically, having a few hours off in a week will help you to stay on top of things.
- Finally, keep an eye on these subjects: Discrete Mathematics II, Operating Systems II, Floating-Point Computation, HW ticks (sorted by the effort they took from me, in decreasing order). They might be different for you, but these particular ones are worth being aware of.
But most importantly - enjoy what you're doing.
Good luck and have fun.
"The Hard Way is the Right Way"
Posted by Manfredas Zabarauskas in Education, Life, Music on April 17th, 2010
While the Europe is paralyzed by the volcanic ash and I am restrained from coming back to Cambridge, here is a quick recap of what I have been doing for the past couple of months.
1. Guitar
It looks like it is becoming a tradition - another vacation ends with a guitar video. This time - a short slow blues in Stefan Grossman's style. The usual apologies for the sound, video and playing quality apply.
2. Professional
I was accepted as a student member to the Chartered Institute for IT (former British Computer Society). For the next two years (at least) I should be reachable through this e-mail: manfredas.zabarauskas@bcs.org.
3. Studies
Without getting into the gory details, the outcomes of the Lent (read: second) term in Cambridge can be summarized by: Conway's Game of Life Mandelbrot set (1280x1024)
- a wallpaper "spit out" by ML depicting a rather standard Mandelbrot set fractal (on the right),
- an animation "spit out" by Java depicting eight-hundred generations of the spacefiller pattern in the Conway's Game of Life (further on the right),
- and an insane amount of material to prepare for the upcoming exams; both broad and not as shallow as I expected.
I am still extremely enjoying it, even though the amount of my spare-time has decreased. (As an afterthought - I still had time to play basketball for Blues, Lions and my college, so maybe it was not that bad).
4. Internship
Over the summer I will be working as a Technology Analyst for Morgan Stanley, in their Innovative Data, Environments, Analytics & Systems (IDEAS) group. Sunrise over Canary Wharf
During the interviews Morgan Stanley really left a very good impression both at the level of knowledge of the people working there and the communication and culture inside the company. We will see if that applies in day-to-day situations. In any case, I have nothing against spending the summer in Canary Wharf and seeing the investment banking industry from inside.
It will surely give me more things to write about in this blog, so be sure to check back once in a while.
Competition: internship offer packs from Morgan Stanley and Citigroup.
Conway's Game of Life
Posted by Manfredas Zabarauskas in Development, Education on April 4th, 2010
Description
In 1970s John Horton Conway (British mathematician and University of Cambridge graduate) opened a whole new field of mathematical research by publishing a revolutionary paper on the cellular automaton called the Game of Life. Suffice it to say that the game which he has described with four simple rules has the power of a universal Turing machine, i.e. anything that can be computed algorithmically can be computed within Conway's Game of Life (outlines of a proof for given by Berlekamp et al; implemented by Chapman as a universal register machine within the Game of Life in 2002). Glider in the Game of Life
The Game of Life is a zero-player game, i.e. the player interacts only by creating an initial configuration on a two-dimensional grid of square cells and then observing how it evolves. Every new generation of cells (which can be either live or dead) is a pure function of the previous generation and is described by this set of rules:
- Any live cell with fewer than two live neighbours dies, as if caused by underpopulation.
- Any live cell with more than three live neighbours dies, as if by overcrowding.
- Any live cell with two or three live neighbours lives on to the next generation.
- Any dead cell with exactly three live neighbours becomes a live cell.
For more information, patterns and current news about the research involving Game of Life check out the brilliant LifeWiki at conwaylife.com.
Implementation
The following applet visualising the Game of Life has been developed as part of the coursework for Object-Oriented Programming at the University of Cambridge, all code was written and compiled in Sun's Java SE 1.6.
Click on any of the screenshots or the button below to launch the Game of Life (and if nothing shows up, make sure that you have the Java Runtime Environment (JRE) installed).
Spacefiller (Game of Life applet)
Read the rest of this entry »
Unplugged in G
Posted by Manfredas Zabarauskas in Education, Life, Music on January 8th, 2010
Another vacation, another video - as usual, apologies for the sound, webcam and playing quality. Three days left 'till the journey back to Cambridge.
Gel electrophoresis of Senecio vulgaris, S. squalidus and S. cambrensis DNA strands.
Post-vacation status update: apparently I did have to discuss plant evolution through polyploidy in my exam! What were the odds...
Anyway, here's the video. Oh, yes, and while we're at it - happy New Year to you all. Eric Clapton - Wonderful Tonight (0:00/3:50),
Guns N' Roses - Wild Horses (3:54/6:16).
It Literally Pays Off to Do Homework in Cambridge
Posted by Manfredas Zabarauskas in Development, Education, Life on November 24th, 2009
"Well done! - joint shortest traditional (and practical :-) sort for the OS1a prize tick". Cambridge, 2009.
45 minutes, 28 MIPS instructions and £25.
Computer Science FTW.
# Copyright Manfredas Zabarauskas, 2009.
# MIPS routine that reads an array of ten integers
# and prints the sorted array to console.
.text
main: sub $t7, $sp, 40
l_read: li $v0, 5
syscall
sw $v0, 0($t7)
add $t7, $t7, 4
bne $t7, $sp, l_read
l_out: sub $t8, $sp, 36
sub $t7, 40
l_inn: add $t8, $t8, 4
lw $t2, -8($t8)
lw $t3, -4($t8)
ble $t2, $t3, no_swp
sw $t2, -4($t8)
sw $t3, -8($t8)
move $t7, $sp
no_swp: bne $t8, $sp, l_inn
beq $t7, $sp, l_out
l_prnt: li $v0, 11
li $a0, 10
syscall
li $v0, 1
lw $a0, 0($t7)
syscall
add $t7, $t7, 4
bne $t7, $sp, l_prnt
li $v0, 10
syscall
White Man's Blues
Posted by Manfredas Zabarauskas in Education, Music on September 24th, 2009
Due to the fact that I have found time to record these videos, I'm starting to suspect that my vacations have prolonged quite a bit... And I still have more than a week left.
A status update: apparently I have been awarded the Simon Gray prize by the Department of Philosophy at the University of Edinburgh. That, a KAL industrial scholarship, a couple of other prizes... I almost regret having to leave.
Anyway, here's the video. Try to figure out which is worse: my playing or my webcam's video quality.
Edinburgh University, Computer Science and Artificial Intelligence, Semester II
Posted by Manfredas Zabarauskas in Education on September 6th, 2009
Labs @ Edinburgh University
As I have promised earlier, here's the second part of my impressions about the individual courses in the first year of Computer Science and Artificial Intelligence at the University of Edinburgh. Hopefully you will find it useful, e.g. when choosing your outside courses, preparing for the exams or simply getting a taste of the CS undergraduate life in the University of Edinburgh.
Once again, please bear in mind that all what is written below represents only my personal opinion.
Innovation and Enterprise for Scientists and Engineers
Professor: Khaled Benkrid
Lectures: a brilliant introduction to the main components and aspects of modern entrepreneurship, definitely one of the most interesting business courses that I’ve been to so far. Not only will you get the basic theoretic concepts of the modern business (like industry, marketing, operational, financial analyses, risk assessment), but you’ll also put them into practice while writing a business plan for your own idea, which will then account for 50% of your final grade.
What’s more, you’ll get the guest talks of local entrepreneurs (either spin-offs from the university, or related in some other way), an overview of the legal system regarding UK start-ups and businesses (PLCs, sole-traders, etc) and on top of that – it will all be related to the science and engineering (with Dr. Benkrid being a computer scientist himself!).
All in all – a highly inspiring, exciting and recommended course!
Exam: well… it all can’t be that interesting. Read the rest of this entry »