When one wants to use the services on the Belgian Federal Government web site, one needs to create an account. therefore, one needs a login and (obviously) a pasword. Now, the rules state that the pasword must only consist of letters and numbers. So, no punctuation characters. How does one generate a strong pasword? One needs to ensure that brute force attacks are not worth the effort, by using a password that contains a lot of characters, and such that each character comes from as large a set as possible. And such that the password cannot be looked up in any dictionary, i.e., it is not an existing word. So, excluding a large portion of the readable ASCII set is not a good thing IMO.
Archive for May, 2007
Password security
Friday, May 25th, 2007Technorati claim post
Thursday, May 24th, 2007A clean ride
Tuesday, May 15th, 2007There has been much ado the last days about a bus built by Van Hool. The vehicle uses an engine that uses hydrogen to generate electricity, emits water, and uses energy captured when breaking to charge batteries it can later use when accelerating again.
I must admit that this seems like a very good thing, until one starts to think a bit further. First the plus points. If all cars use this system, we would not have all the filthy emissions of exhaust fumes in our cities. Second, we might save some energy, because of the break-energy-capture system. But what about the drawbacks? The media seem to focus only on these benefits. However, the hydrogen needs to be acquired somewhere, right?
There are several ways to do this. One of them is electrolysis, but that does not seem to be the most efficient technique around. Even if it is, you need to generate that electricity somewhere. For example using wind. The question then remains if it would not be better to directly use that electricity instead of ‘storing’ the energy in hydrogen that is to be used later. Afaik, storing energy in some intermediate carrier always causes the loss of some portion of said energy.
Another way is by tranforming gas, which is the technique employed right now to acquire hydrogen for the hybrid bus. Methane can be split into carbon monoxide and hydrogen, using a bit of water. But the temperatures required for this are high (700 – 1100 degrees celsius), so a bit of methane must be burned, yielding, indeed, carbon dioxide. The carbon monoxide can be further processed at a lower temperature, again reacting with water, to form carbon dioxide (well, well … did we not try to avoid this?) and hydrogen and some left over energy.
So either way, if we think that going hybrid on hydrogen is going to solve all the issues, we’re very wrong, and the media should do a better job of reporting not only the benefits, but also the drawbacks. That said, I am in favour of cleaner forms of energy, and I’m quite certain that reducing smog is a benefit that is not ot be underestimated.
Using HPM-Sampling to Drive Dynamic Compilation
Saturday, May 12th, 2007The following paper has been acepted for publication at OOPSLA 2007.
Using HPM-Sampling to Drive Dynamic Compilation, Dries Buytaert, Andy Georges, Michael Hind, Matthew Arnold, Lieven Eeckhout, and Koen De Bosschere.
The paper abstract reads as follows.
All high-performance production JVMs employ an adaptive strategy for program execution. Methods are first executed unoptimized and then an online profiling mechanism is used to find a subset of methods that should be optimized during the same execution. This paper empirically evaluates the design space of
several profilers for initiating dynamic compilation and shows that existing online profiling schemes suffer from several limitations. They provide an insufficient number of samples, are untimely, and have limited accuracy at determining the frequently executed methods. We describe and comprehensively evaluate HPM-sampling, a simple but effective profiling scheme for finding optimization candidates using hardware performance monitors (HPMs) that addresses the aforementioned limitations. We show that HPM-sampling is more accurate; has low overhead; and improves performance by 5.7\% on average and up to 18.3\% when compared to the default system in Jikes RVM, without changing the compiler.
Montréal, here we come. October 21st – October 25th it is!
This paper has quite a long history behind it. Dries and I conceived the idea while attending the ACACES summerschool in July 2006. After a long talk with Mike, we decided to launch some preliminary measurements with the system Dries had already built into Jikes RVM using the HPM interface I had adapted from Steve Blackburn‘s perfctr patch for Jikes RVM. We intially targetted PLDI 2007, when some matters were brought to our attention, that questioned our original idea on the current state of the art. Submission was postponed, extra experiments were conducted and we targetted VEE instead, where our paper was rejected. Based on the reviews we received there, it seems like it was a border case, but a rejection nonetheless. So, we figured, why not submit to OOPSLA. Worst case scenario: we get additional reviews to improve our paper. I turns out that the Best Case Scenario was visited upon us instead. You can get a preprint version.
Reaper's Gale
Friday, May 11th, 2007Dispatched on Monday, May 7th. Arrived at my doorstep on Thursday, May 10th. One box from Amazon. Contents: The next installment in the Malazan Books of the Fallen series.
I disliked the cover when I first saw it, but I’ve come round, and in fact, right now, I sort of like the image of Rhulad (I think) sitting on his throne. I still dislike the font used for the author and title.
I am forcing myself not to start reading right away, because I’ve got a ton of other stuff to do, and once I start, there will be no stopping. But hey, it’s mine 
My own very personal 128 bit key.
Tuesday, May 8th, 2007I have just obtained all the rights to the following key 128-bit key: “4A 69 BA 36 BF 5D 02 28 4C BA B0 DA 80 E8 2C 9C”. I’ve been handed the rights to this key for encrypting and decrypting the haiku you can find here. So it’s mine and mine alone. I’ll be scanning every single binary on every system I encounter and if I even sniff a hint of my key, I’ll be suing whoever authored that binary.
WordPress 2 drupal
Thursday, May 3rd, 2007I used to have a wordpress blog at Ghent University, but since acquiring the itkovian.net domain, I decided to move to drupal. However, every tool I found to port my posts over was targetting drupal < 5.0.
A darcs repository is available for a Python script that takes out posts from a wordpress database and injects them into drupal. The code is licensed under the GPL-2, so feel free to extend it.
At the moment this script will only transfer posts, without comments. To transfer the wordpress categories, it requires a free tagging vocabulary, and you need to know its ID in your drupal install (you can find this at ‘admin/content/taxonomy’ and selecting list terms for the chosen vocabulary). It also requires a minor patch to the drupal blogapi module, to allow the wordpress post dates to be taken along. You need a configuration file with a [wordpress] and [drupal] section, detailing the hostname, database, login info, etc. Example configuration files are provided.
You can get the required files by
darcs get http://itkovian.net/darcs/wordpress2drupal
If you choose to extend the code, you can email the darcs patches to itkovian drats gmail drots com.
Resume
Thursday, May 3rd, 2007Personal Information
| Name: | Andy Georges |
| Address: | Onafhankelijkheidsstraat 6 |
| 8400, Oostende | |
| Belgium | |
| Sex: | Male |
| Date of birth: | October 7th, 1977 |
| Marital status: | Married to Veerle Hanssens |
| Children: | Elias and Nathan |
Publications
-
Statistically Rigorous Java Performance Evaluation[pdf]
Accepted for publication at the 22th ACM SIGPLAN Conference on Object-Oriented Programming Systems, Languages and Applications
October 21-25, 2007
Montreal, Canada- Using HPM-Sampling to Drive Dynamic Compilation
Accepted for publication at the 22th ACM SIGPLAN Conference on Object-Oriented Programming Systems, Languages and Applications
October 21-25, 2007
Montreal, Canada- Performance Prediction based on Inherent Program Similarity.
Proceedings of the Fifteenth International Conference on Parallel Architectures and Compilation Techniques (PACT). ACM.
2006.
pp. 114-122- Comparing Low-Level Behavior of SPEC CPU and Java Workloads.
Proceedings of the Advances in Computer Systems Architecture: 10th Asia-Pacific Conference, ACSAC 2005. Springer-Verlag GmbH. Lecture Notes in Computer Science. Vol. 3740.
2005.
pp. 669-679- Towards an extensible context ontology for Ambient Intelligence.
Proceedings of the 2nd European Symposium on Ambient Intelligence. Springer. LNCS. Vol. 3295.
2004.
pp. 148-159- Method-Level Phase Behavior in Java Workloads.
Proceedings of the 19th ACM SIGPLAN Conference on Object-Oriented Programming Systems, Languages and Applications. ACM Press.
2004.
pp. 270-287- Bottleneck Analysis in Java Workloads using Hardware Performance Monitors.
Companion of the Proceedings of the 19th ACM SIGPLAN Conference on Object-Oriented Systems, Languages and Applications. ACM Press.
2004.
pp. 172-173- JaRec: a portable record/replay environment for multi-threaded Java applications.
Software – Practice and Experience. John Wiley & Sons, Ltd.. Vol. 34 (6).
2004.
pp. 523-547- Selecting a Reduced but Representative Workload.
OOPSLA 2003 Workshop on Middleware Benchmarking: Approaches, Results and Experiences- How Java Programs Interact with Virtual Machines at the Microarchitectural Level.
Proceedings of the 18th Annual ACM SIGPLAN Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA 2003). ACM.
2003.
pp. 169-186- A Taxonomy of Execution Replay Systems.
International Conference on Advances in Infrastructure for Electronic Business, Education, Science, Medicine, and Mobile Technologies on the Internet
2003.
pp. CDROM paper 59 - Using HPM-Sampling to Drive Dynamic Compilation