[Advanced Databases]: Welcome to Advanced Database Systems

Welcome to ADS! This course will have a little bit of everything: traditional lectures, home work assignments (on a voluntary basis), a small (half a day) practicum assignment, a small project, and a written exam. You are going to learn how relational databases work in practice: what happens inside the system when an SQL query is executed? In the 2nd part of the course, we are going to discuss applications for which relational databases do not provide a perfect solution: object-oriented data, semi-structured data, distributed data and online analytical processing.

See you in September,
Djoerd.

[Information Retrieval]: Welcome to the course Information Retrieval

Next Wednesday, 5 September 2007, we start our full semester course Information Retrieval. I think we have put together and interesting course with a number of guest speakers with international reputation.

In November, we will switch from lectures to small research projects in which students participate actively in research done at the University of Twente. In this second part, the meetings will be used to set up a discussion forum in which all participants actively exchange their ideas, progress and problems encountered.

If you did not already do so, please buy the reader Information Retrieval.
We wish you a fruitful course!

Who is the center of the SIGIR universe?

Last year, in Seattle, Jon Kleinberg gave a keynote speech about social networks, incentives and search. In social networks, it is not about what you do, how much you do, or where you're from, it is about who you know. To celebrate SIGIR's 30th anniversary, we analysed all SIGIR proceedings and built a social network in which SIGIR authors are the nodes and edges are added between nodes if two authors co-authored a SIGIR paper together. The author that is most central in the network, is the one that has the shortest average distance to all other authors, where the distance is 1 if two authors wrote a SIGIR paper together, it is 2 if the first author wrote a paper with someone who wrote a paper with the second author, etc. It turns out that the center of the SIGIR universe is Wensi Xi from Google. Congrats Wensi! More info on: Search demo (See the Oracle of Xi)

Building Detectors to Support Searches on Combined Semantic Concepts

by Robin Aly, Djoerd Hiemstra, and Roeland Ordelman

Bridging the semantic gap is one of the big challenges in multimedia information retrieval. It exists between the extraction of low-level features of a video and its conceptual contents. In order to understand the conceptual content of a video a common approach is building concept detectors. A problem of this approach is that the number of detectors is impossible to determine. This paper presents a set of 8 methods on how to combine two existing concepts into a new one, using a logical AND operator. The scores for each shot of a video for the combined concept are computed from the output of the underlying detectors. The findings are evaluated on basis of the output of the 101 detectors including a comparison to the theoretical possibility to train a classifier on each combined concept. The precision gains are significant, specially for methods which also consider the chronological surrounding of a shot promising.

[download pdf]

SIGIR 30th Anniversary Search Demo

SIGIR will have its 30th conference this year. To celebrate this, we created some fun search applications that search the abstracts of 30 years of SIGIR proceedings at: http://www.sigir2007.org/search.

Enter your favorite IR topic to search in the abstracts of 30 years of SIGIR and find experts, periods and geographical locations associated with your search. The “mystery link” will be revealed at the conference in Amsterdam.

[XML & Databases 2]: Additional assignment opportunities

Due to the much larger number of students than we expected, we perhaps need to have additional assignments to accomodate everybody. This will be done on a per theme-basis, i.e. we will assign more project groups to a theme than there are assignments. On the first theme meeting, we will explain which other possible assignments can be done, so we can discuss what each group is going to do. If desired, there is the opportunity to switch assignment within the theme.