Ondrej Skopek

TransportEditor (bachelor thesis project)

Fri, 20 Oct 2017 00:00:00 +0000

This June, I successfully defended my bachelor thesis at Charles University. During the spring semester, I spent countless hours working on my thesis on the topic “Planning for Transportation Problems”. Let me explain in several steps, what the thesis attempts to solve.

Picture: TransportEditor showing an example Transport problem.

Automated planning is a field of artificial intelligence, that deals with designing sequences of actions for intelligent agents with respect to some objective. Specifically, in my thesis, intelligent agents correspond to trucks delivering packages to their destinations in a road network (for a more precise definition, see Chapter 2). Planning (and scheduling) rely heavily on more theoretical fields like combinatorial optimization, reinforcement learning, or combinatorial search (Chapter 1).

Several variants of the mentioned problem were discussed and solutions to some were proposed. Specifically, we focused on datasets used at the International Planning Competition (IPC)) for the “Transport” planning problem. We propose several domain-specific (customized for the “Transport” problem) algorithms for devising plans, i.e. sequences of “drive”, “pick-up package”, and “drop package” actions for vehicles.

Leveraging knowledge about our problem, we managed to beat almost all competing domain-independent (not “Transport”-specific) planners. For detailed results, see Chapter 6. Our approach shows that such knowledge can be effectively incorporated into known planning techniques, and successfully used to create better plans, and create them faster.

To visualize our work, we developed TransportEditor, a desktop GUI application for viewing and creating Transport problems and solving them using external and embedded planners.

Video: Demo of an older version of TransportEditor.

TransportEditor was presented at the System Demonstrations and Exhibits track at the International Planning and Scheduling Conference (ICAPS) 2017 in Pittsburgh, USA. The paper can be read here.

In the meantime, I graduated from Charles University, and after a great summer that I spent interning at Google in Munich, I am now studying at ETH Zurich in Switzerland (more on that in a followup post).

Slides from the presentation.

How programming can help solve (almost) all your problems

Fri, 14 Oct 2016 00:00:00 +0000

Today I had a short talk with the students at my old high school in Slovakia.

We talked about informatics, data and the students’ views on its use in modern society. I strongly feel that programming will find its place in a lot of workplaces even outside of software engineering. We discussed their ideas, which I tried to illustrate by showing them some cool examples related to software popping up in unexpected places.

You can take a quick look at the slides, but unfortunately, they’re only in Slovak.

At the end, I presented my proof-of-concept idea of teaching a voluntary extra-curricular Intro to Computer Science course. I’ll post more information about this later, if someone signs up :)

P.S.: Check out the talk I did last year.

Microsoft Summer Internship in Oslo

Fri, 23 Sep 2016 00:00:00 +0000

Today is the last day of my summer internship at Microsoft. During the last 12 weeks, I met an insane amount of very interesting and intriguing people from all parts of the world.

Photo: Hackathon Science Fair.

Microsoft Developer Center Norway (previously FAST Search & Transfer, acquired in 2008) is a diverse group of talented and resourceful people that love what they do. This summer, I helped out with Continuous Delivery of the Search technology, developing an internal tool for better monitoring and quicker issue response.

Photo: Clubs near Grünerløkka on the Akerselva river.

Apart from the actual work, I got to explore Oslo, took a week long solo trip across South Norway, travelled together with the other interns for a Europe-wide Microsoft Internship Event to Dublin, got to know Norway and Norwegians as a society and had fun doing it!

Photo: View from the Oslo office after Lønningspils.

Take a short photo-tour of my trip through Stavanger, Preikestolen (Lysefjord), Hardangerfjord & Hardangervidda, Bergen and Flåm:

Photo: Preikestolen fjelstue.

Photo: Lysefjord from Preikestolen.

Photo: Trolltunga!

Photo: Torehytten and Harteigen.

Lubka and Juraj visited during their Scandinavian tour and we went to see the city.

Photo: Operahouse with Lubka, Juraj and Katka.

At the end of August, Microsoft flew all the interns in Europe to Dublin for a weekend of free beer, team-building events and Dublin nightlife. I really enjoyed the bar atmosphere in Dublin (The Porterhouse!) and had lots of fun meeting other like-minded people from all over Europe.

Photo: Almost all Norwegian interns on ready to board the plain to Dublin.

Photo: Liberty Hell at the Porterhouse.

Photo: Most of Microsoft’s 2016 Europe Interns.

Silvia came to visit and we rented a car and went to see Gaustatoppen with Anca and Matei.

Photo: Gaustatoppen ascent.

Photo: View from (almost) the top.

While Zuzka came to visit in September, we had a hackathon at work. Me and Jonas designed and implemented a tool to load balance Oslo’s City Bike stations for greater availability.

Photo: No more arguing over too few bikes!.

Photo: An example of a prediction.

Photo: Our Hackathon presentation.

Photo: Fun in the office during the Hackathon.

For the rest of my internship, I tried to finish up and hand over any remaining work and hand over what I built, explore the remaining coffee places I wanted to and worked on my school project.

Photo: Coffee at Tim Wendelboe’s with Karolina and Matei.

Photo: Intern goodbye grill party at the beach in Huk.

One of the things I regret is that I didn’t have enough time and/or will power to finish my individual software project at school, so I’ll probably have to finish it next semester. My third year at Matfyz starts in bit more than a week.

I really enjoyed this summer - it was a wonderful new experience, at Microsoft and outside it. The best part were definitely my wonderful colleagues - the culture and coherency at FAST was exhilarating and I wish them all the best while facing new challenges in the future. Especially, I want to thank my team, my buddy Grant and my manager Manolis for the extensive help, support and knowledge they gave me during my short stay.

Thanks for the amazing summer!

StudyGuide

Mon, 15 Aug 2016 00:00:00 +0000

Planning and verifying tool for all the requirements of your studies

As part of a two semester Java course last year, I designed and implemented a simple JavaFX desktop app for keeping your studies on track.

It can import data from SIS, an integrated school information system that my university uses, but you can also enter your course data yourself: either manually in the app, or create a valid JSON (see README on how to do that) and import it.

The app will verify any constraints you place want to check your study plan for (minimum credit number, etc.). Give it a try now!

If you encounter any issue or have question, feel free to open a new issue on GitHub.

Happy ~~studying~~ planning!

It's summer again!

Wed, 22 Jun 2016 00:00:00 +0000

Another few months went by fast and it’s already summer break again. All my exams are finished, all that’s left are the two programs I have to write in order to get the last few credits.

A lot happened during the last few months:

a couple of friends and me took part in the Volkswagen Prague Marathon 2016 Relay as part of the University Cup run
I got accepted into Microsoft’s summer internship program and I’ll be working full-time at MSFT during the summer in Oslo, Norway!
My adviser and me agreed on my bachelor thesis topic and I’m slowly starting to work on that too
Matej and me started to write down a short summary of last year’s biking trip from Bratislava to Salzburg, which I’ll add a link to here shortly

The past few months have been very hectic and I’m excited to take few days off and go hiking with Lukas, Tom and Matej into Krkonose. Next academic year, there will be less exams for me and more work on my bachelor thesis and other projects (and hopefully more free time). Have a nice summer!

End of the fall semester 2015

Fri, 26 Feb 2016 00:00:00 +0000

Well, technically, it’s already the spring semester here in the Czech Republic.. but so much stuff happened a few weeks back that I didn’t have time to write about it then.

First of all, I passed all 7 of my exams! Think I’m getting the hang of this slowly. Also, during that, I managed to attend DevConfCZ 2016, which was just a blast.

As a reward, we went skiing to South Tyrol/Northern Dolomites/Northern Italy. Technically, it was a university course – but (thankfully) only on paper. Four days of pure skiing and hanging out with cool people of all ages, most of them from Matfyz. Take a look at some of my pictures and all the GPS data I collected.

Regarding my plans for the future:

Studying, d’oh! The spring semester is going to be tough (9 courses, 8 exams)
A major research/software project at school (trying to come up with a topic that would accentuate or even be followed up by my bachelor thesis next year)
Look for some summer employment/internship opportunities!

DevConfCZ 2016

Fri, 05 Feb 2016 00:00:00 +0000

Whoah, this conference just keeps getting bigger and better. The organizers counted about 1200 people just in the first day. I remember attending about 5-6 years ago, there were about 120 people in total. Also, check out my post from last year’s DevConfCZ.

Just check out the #DevConfCZ Twitter hashtag for proof. Also, the coffee from Kofi Kofi was just amazing.

Several minor problems occured to me during the weekend:

Lack of recycling trash bins
8 parallel sessions, anyone? – during some time slots, I’ve definitely been in need of Hermione’s time turning thing. How can you attend 3 talks at the same time? (Answer: YouTube live stream + archive!)

Here’s a short summary of talks I attended. Most of them you can find in Red Hat’s YouTube channel.

Friday, February 5th

JW: Keynote: Teach organizations open source methodology (The Open Source Way!)
MS: Microservices and KIE (Knowledge is Everything)
MV: SilverWare intelligent house systems + handling IoT intelligently
SB: JBoss Forge + JBoss Tools rock!
MF: CI/CD on Jenkins + OpenShift
JF: FeedHenry + Red Hat Mobile Platform
AK: Arqullian Cube
BG: Wildfly Swarm
JC: Elytron

Saturday, February 6th

Docker4JEE: Fabric8!
jzb talks community
MW: .NET Core workshop (Omnisharp, VIM c# code completion)
VJ: From big data to fast data: Apache spark (lazy evaluation), Samza, Storm, Flink… Infinispan
JK: RxProgramming: Principles of Reactive Programming
OracleGuy: Graal + Truffle instead of your own compiler
LVH: JMH, value types in Java (Valhalla project)
MS: Transitioning from Java to Go
Security: Everything is on fire
.NET Core

Sunday, February 7th

MH: Cython
SELinux
Quantum crypto
Devs, QEs of themselves
Code Auditor
TryStack
Dev Evangelist talk

All of them were very good, some were indeed great. The best are highlighted in the list.

Linux Days 2015

Sun, 11 Oct 2015 00:00:00 +0000

This weekend I attended the LinuxDays conference at FIT CVUT in Prague. In between studying, I got to see some talks, most of which were quite good. The ones I liked most were:

Grafy a datová analýza v Gnuplotu by Ondřej Guth
Poor Man’s Cloud by Jan Baier
Kubernetes - úklid mezi kontejnery by Tomáš Kukrál

Good morning from #LinuxDays! Photo by: me

A big thank you to the organizers, looking forward to next year!

TriExpert Cup 2015

Fri, 02 Oct 2015 00:00:00 +0000

This week, my internship at Red Hat ended. During the summer, I’ve worked part-time as a Software Engineering Intern at Red Hat’s office in Brno, Czech Republic. Coincidentally, a lot of the people there are avid cyclists and runners - which I am, too!

It was they who told me about TriExpert Cup, a weekly amateur running league in and around Brno. Every Wednesday, a group of 5-10 colleagues car-pool to the venue and race against each other (and against 200 other people!) out of fun and love of running. I was thrilled to join, even though the league was already in full swing and half of the races have already been run.

As I found out after one or two races, a good placement overall in the Men’s Junior category (where I belong according to my age) is quite possible for me this year! So I made a promise to myself that I would at least try to run my best and see how it turns out. But more about that later. Here’s a short recap of all the races I attended, with pictures.

Pisarky

My first TriExpert cup race! I was excited, but didn’t know what to expect. The course was short, just 6K: uphill for 1.5K, then downhill for 1.5K and back again. It was really hot - 36°C in the shade. I got through pretty much ok, in 26:07, which gives a 4:21 min/km average pace. That was just enough for 2nd place in my category.

Palackeho vrch

The course was just behind Red Hat’s new office where I work, so the warm up consisted of actually commuting to the registration booth. Unfortunately, I positioned myself too far back at the start, and lost quite some time because of the very narrow trail for the first two kilometers. After that, we hit a gravel road I regularly train on, and gained some time back. Overall, 7.1K in 31:05 with very steep hill before the finish line made for a 4:22 min/km average pace and 3rd place in my category.

Obrany

A totally foreign course to me: straight along a river for 4.4K, then back. Didn’t know what to expect, so held back at the beginning and let the second half roll - in total, 37:54 for a 4:18 min/km average pace and 3rd place in my category. Also, I beat Honza just before the finish line!

5K track

Track day! 5K was on the menu today. The problem was, I had to race the first heat, because I had some errands later

and it was very hot. Wanted to go below 20 minutes, which didn’t quite work out. Finished in 20:15 with an average pace of 4:02 min/km and got a feel-well present for my failed goal: I won my category!

Lisen

Total downpour, all day long. We were wet even before it all began. 11K of puddle hopping and mud stomping seemed like quite a bad outlook, but wasn’t after the heat waves of the weeks before. The course unwinded itself for 5.25K and then back along a river, in the shade of a forrest. Managed to win my category again - in 46:35, with an average pace of 4:26 min/km (I was saving myself for a hike I had planned for the weekend, but the better guys didn’t come).

Popuvky

Probably my favorite course - starts with a brutal uphill and basically stays uphill for 4K, then downhill for 4K to complete the loop. Most of it was in the forrest - which was great, given that it started to get hotter again. Although I got stuck in traffic at the beginning, managed to get back and win the race - in 33:45 with a 4:16 min/km average pace. Also, for the first time in my life, I managed to be faster than all the women in the race.

10K track

Back to the track, this time for 10K. Vlado and Jirka didn’t run today, so they cheered us on from the stands. Wanted to beat my PB from last year from Branik in Prague (41:55) - which I managed to do, by more than 30 seconds! There were way too many people in my heat, so came in at 41:24 on the clock with an average pace of 4:08 min/km

which was just enough to win my category!

Over the weekend, I raced another 10K on the road in Myjava in a better pace (4:07 min/km)

the problem was, in the end, it was just a 9.6K.

Lisen (again)

Back to Lisen, this time for an 11K. I ran the first half with Honza, after which he told me that he doesn’t feel well and I should go if I wanted to. So I picked up the pace, eventually caught on to the first woman in the race. With about 2K to go I passed her, and also another colleague, Pavel. Saw Tomas in the finish, but couldn’t run him down. Vlado was 10th overall and won his category! I won mine too, in 45:42 with an average pace of 4:09 min/km.

Pisarky - Anthropos (again)

The last race on the traditional TriExpert courses. The weather was better than last time I was here (my first TriExpert race!). Also, I knew what to expect this time. I felt tired from the 110K hike I did over the weekend, and also had some lingering Achilles heel and knee pain from that. Nevertheless, the race turned out nice - even though I was 4th in my category I ran a solid time of 24:19, which is 4:03 min/km.

Blazovice - St. Wenceslav run

The last race (actually not organized by TriExpert) took place in Blazovice on Monday, October 28th, which is a national holiday in the Czech Republic. My biggest rival in the cup turned out to be Petr - we had a 30 point difference in our total scores. That meant, that if one of us failed to turn up today, the other one would win. Unfortunately for me, I was the one down 30 points and we both showed up. I tried to hang on to him for about 6 kilometers, but felt the pace was too fast for me. After slowing down, I knew had had enough. Hurting for the rest of the race, even people that I beat regularly plowed past me. The 11K course had to come to an end and did - it took me 46:52 with an average pace of 4:16 min/km. Petr (after today, the winner of TriExpert Cup in the junior category) beat me by more than 2 minutes today.

Final summary and ceremony

The final ceremony took place in a school in Brno on Wednesday, October 30th – with a double podium for Red Hat JBoss Middleware!

Vlado placed 3rd in Men’s B category (40+), and I placed 2nd in the Men’s Junior category. We both enjoyed the ceremony and were very grateful for the prizes.

Overall, the cup was very exciting, a great experience and race. I hope I’ll be able to try my luck next year too!

Summer Internship at Red Hat - Part 2

Thu, 01 Oct 2015 00:00:00 +0000

Yesterday was my last day at Red Hat (for now). It was a wonderful 2.5 months and a brand new experience for me, and I’m quite sad it all ended so soon. New things await me - my second year at Matfyz starts in less than a week.

Photo: My first day at Red Hat

First of all, I want to thank Geoffrey for contacting me in the spring about such a position being opened, and for all the support, feedback, criticism, ideas and concepts he shared with me.

Second, my manager, Shelly for hiring me in the first place, and for her support during the whole course of my internship. I have to mention Petr for helping me with my first days at Red Hat and for all technical and non-technical help during my stay.

Lastly, I can’t forget the whole KIE Group

the developement team and the QE team - which I sat next to in the Brno office. More specifically, thanks to all contributors of OptaPlanner.

Thank you Red Hat for being such an awesome company. Let’s see what next year has in store for me!

P.S.: Read my blog post on the impact of random seeds on OptaPlanner!

P.P.S.: Here is a lengthy report, of what I actually did during my internship!