promees.es — a weekend’s experiment October 15, 2013Posted by CK in Networking, Research, Software.
Tags: Facebook, promees.es, promises
add a comment
There is this concept I have been thinking about for quite some time now, and this weekend I got around to kicking off its development. There are additional things I want to implement for it, but in its current form it is probably ok to publicize. So here’s the idea: People make promises constantly. “I’ll fix this for you”; “Sure, I’ll review your work”; “I’ll take you on a holiday”; you get the drill. People are judged by how good they are keeping their promises. Abiding to your promises is, in real life, one of the main reasons why others respect you.
Another thing happening in real life is that this respect is communicated in private conversations. But what would happen if people were able to advertise an index of their capability to hold on their promises? Would this be of value to their peers? This site is an experiment to figure out such questions, using Facebook as a platform.
Feel free to give it a try at promees.es and get back to me with thoughts/comments you may have (keeping in mind that it was built in 3 days or so, so dont’ be harsh!).
PuLP modeler June 12, 2010Posted by CK in Research, Software.
Tags: CBC, COIN-OR, CPLEX, GLPK, Gurobi, MILP, Optimization, PuLP, Pyomo, Python, SCIP
add a comment
I have to solve some optimization models, and looked out there for relevant tools. Solvers is one thing, and there’s a number of options depending on the money you can(not) spend, your requirements, etc. Modelers is another game though, and it took me some time to decipher the various options. What output (i.e. solver input) they can produce, by which solvers this input can be used, if there are converters, etc.
Eventually I went with PuLP, and do not regret it so far. It supports GLPK, COIN-OR, Gurobi and CPLEX. That’s basically all the solvers I wanted to test my models with (except for SCIP, which however I had terrible problems installing and I skipped it).
PuLP installation on the MacOS was as easy as “easy_install pulp”, and then it just worked. From a modeling perspective, I don’t find it to be very intuitive, but it does the work nevertheless, so I can’t complain. The fact that modeling is done in Python code is of course the greatest advantage. As a PuLP rookie, I had the first model ready and running in less than two hours today (including fixing a nasty bug in my code). There’s one more open-source, python-based modeler, Pyomo, but it supports less solvers (although I understand they’re working on it).
Finally, since we’re at the topic of optimization problems and solvers, maybe you’re interested in some recent benchmarks I came across. I was mostly interested in COIN-OR’s CBC, Gurobi and CPLEX, all for (mixed) integer linear problems. You can find them here and here.
Combinatorial Optimization May 24, 2010Posted by CK in Research.
Tags: Approximation Schemes, FPTAS, Papadimitriou, PTAS, Steiglitz
Although I’m not a huge fan of Papadimitriou’s and Steiglitz’ book, one has to appreciate the things that set this book apart from many others in the area. Looking at section 17.3 on approximation schemes, the intuitive description of the topic is excellent. Starting with the simplest definition of dynamic programming that I’ve ever encountered, and by far the best example ever (example 17.3 — why hasn’t anyone included something so clear in all the places I’ve looked?), then continuing to (F)PTAS so smoothly that one doesn’t even notice.
Bonus points for the last sentence before definition 17.3:
Such a favorable state of affairs naturally calls for a definition.
Too many “17.3” in this post.
Copyright form April 21, 2010Posted by CK in Research.
Tags: Publications, Springer, WIN
add a comment
I received a copyright submission request for a workshop paper that will be published in a book by Springer, and noticed the following at the end:
Please note that we also need you to compile the permission document (Permission.doc) for any material in your chapter (long quotes, figures, tables, etc) that has been published previously. Also if all the material in your chapter is original we need an email from you stating that.
Very interesting excerpt, that makes you think twice if you’re (self-) plagiarizing. Be it a publisher’s policy, or a workshop policy, I strongly hope others will follow.
Hateful reviewers October 25, 2009Posted by CK in Funny, Research.
Tags: Conferences, Hate, Papers, Reviews, Science
Sometimes, you submit a paper to a conference, and you know the chances are somewhat slim based on usual acceptance rates. So you are familiarized with the idea that your paper will be rejected, but don’t quite expect what happens then. You get your 4 reviews, and one reviewer is very happy with your paper. You get a 9/10 overall. Then the other two are posing some reasonable questions, but still they both give you a 7/10 overall. And then, then comes one who basically provides all kinds of completely useless, stupid, unjustified, plain wrong comments, and gives you a 2/10 — even on paper organization, that the others all marked with an almost perfect grade. Now I have a few ways to interpret this behavior, none of which can be elaborated without becoming too explicit. I mean, this just shows hate. If it wasn’t a blind review, I would seriously think it was personal. Don’t get me wrong, I’ve had papers rejected before, and I’m perfectly ok with that, when it comes with justified comments and useful advice. But when it happens without those, it’s just bothering me.
I hate hateful reviewers, and some times, I just hate my luck (or lack of luck, thereof).
What’s in a Service Level Agreement? March 17, 2009Posted by CK in IT, Research.
Tags: eContracting, QoS, Service Level Agreements, SLAs
add a comment
Here’s a link to a short post I wrote for the site of the project I am working on. Comments are welcome 😉
Remote Instrumentation at eScience’08 December 11, 2008Posted by CK in IT, Research.
Tags: DORII, eScience'08, OGF, Remote instrumentation, RISGE
add a comment
Today I had the pleasure to talk at IEEE eScience’08 about a Remote Instrumentation topic  — more specifically about reservation of instruments for remote use. I was very pleased to see how interested people are on the topic, which has been around for some time but clearly we have only scratched the surface. Remote access to instruments for data acquisition and/or control could have enormous impact on society, if done correctly. Just imagine how people in poorer countries would have the possibilities to do experimental science using facilities that they neither have in their countries nor can they even travel to use. Or the impact on business, in a system where companies could rent their equipment to others in such a scheme, much like today’s cloud computing. And don’t forget education! Students from one university could experiment remotely on equipment in other universities, possibly at the other end of the world. The possibilities are endless and include more or less all fields of societal activity.
There are many people working on the topic, such as ex-colleagues from the DORII project. Today I also found out about some very interesting work at the Ohio Supercomputer Center with its RICE project. Last but not least, there’s work taking place in the context of the RISGE Research Group of the OGF, so if you are interested in the topic, subscribe to the RISGE list and join at the next OGF event!
On EU’s ICT research agenda September 16, 2008Posted by CK in IT, Research.
Tags: EU, ICT, Spinellis
Diomidis Spinellis is an associate professor at the Athens University of Economics and Business, and a globally respected hacker. His blog is always interesting to read, and today’s post deserves to be mentioned. Diomidis argues that the central planning of ICT research in the European space delivers sub-optimal results, as the researchers participating in FP ICT efforts chase delivery dates for “micromanaged research projects planned to address yesterday’s needs in a 24 month timeframe” (sic). In contrast, he refers to Bell Labs and the unrestricted work carried out there in past decades, effectively resulting in six Nobel prizes. A short post worth your time.