Abstract: Plagiarism in the sense of “theft of intellectual property ” has been around for as long as humans have produced work of art and research. However, easy access to the Web, large databases, and telecommunication in general, has turned plagiarism into a serious problem for publishers, researchers and educational institutions. In this paper, we concentrate on textual plagiarism (as opposed to plagiarism in music, paintings, pictures, maps, technical drawings, etc.). We first discuss the complex general setting, then report on some results of plagiarism detection software and finally draw attention to the fact that any serious investigation in plagiarism turns up rather unexpected side-effects. We believe that this paper is of value to all researchers, educators and students and should be considered as seminal work that hopefully will encourage many still deeper investigations.

In this dissertation I argue that modal type systems provide an elegant and practical means for controlling local resources in spatially distributed computer programs. A distributed program is one that executes in multiple physical or logical places. It usually does so because those places have local resources that can only be used in those locations. Such resources can include processing power, proximity to data, hardware, or the physical presence of a user. Programmers that write distributed applications therefore need to be able to reason about the places in which their programs will execute. This work provides an elegant and practical way to think about such programs in the form of a type system derived from modal logic. Modal logic allows for reasoning about truth from multiple simultaneous perspectives. These perspectives, called "worlds," are identified with the locations in the distributed program. This enables the programming language to be simultaneously aware of the various hosts involved in a program, their

Abstract. In this paper, we document our efforts at INEX 2007 where we participated in the Ad Hoc Track, the Link the Wiki Track, and the Interactive Track that continued from INEX 2006. Our main aims at INEX 2007 were the following. For the Ad Hoc Track, we investigated the effectiveness of incorporating link evidence into the model, and of a CAS filtering method exploiting the structural hints in the INEX topics. For the Link the Wiki Track, we investigated the relative effectiveness of link detection based on retrieving similar documents with the Vector Space Model, and then filter with the names of Wikipedia articles to establish a link. For the Interactive Track, we took part in the interactive experiment comparing an element retrieval system with a passage retrieval system. The main results are the following. For the Ad Hoc Track, we see that link priors improve most of our runs for the Relevant in Context and Best in Context Tasks, and that CAS pool filtering is effective for the Relevant in Context and Best in Context Tasks. For the Link the Wiki Track, the results show that detecting links with name matching works relatively well, though links were generally under-generated, which hurt the performance. For the Interactive Track, our test-persons showed a weak preference for the element retrieval system over the passage retrieval system. 1

Mobile devices become smaller and more powerful with each generation distributed. Because of the tiny enclosures the interaction with such devices offers limited input capabilities. In contrast there are hardly any mobile phones purchasable that do not have a built-in camera. We developed a concept of an intuitive interaction technique using optical inertial tracking on mobile phones. The key of this concept is the user moving the mobile device which results in a moving video stream of the camera. The direction of the movement can be calculated with a suitable algorithm. This paper outlines the algorithm Projection Shift Analysis developed to run on mobile phones. 1.

Abstract. Document retrieval techniques have proven to be competitive methods in the evaluation of focused retrieval. Although focused approaches such as XML element retrieval and passage retrieval allow for locating the relevant text within a document, using the larger context of the whole document often leads to superior document level ranking. In this paper we investigate the impact of using the document retrieval ranking in two collections used in the INEX 2008 Ad hoc and Book Tracks; the relatively short documents of the Wikipedia collection and the much longer books in the Book Track collection. We experiment with several methods of combining document and element retrieval approaches. Our findings are that 1) we can get the best of both worlds and improve upon both individual retrieval strategies by retaining the document ranking of the document retrieval approach and replacing the documents by the retrieved elements of the element retrieval approach, and 2) using document level ranking has a positive impact on focused retrieval in Wikipedia, but has more impact on the much longer books in the Book Track collection. 1

Abstract: There are various Knowledge Management Systems available currently and designed to support knowledge sharing and learning. An example of these are “Experiencebased Information Systems ” in the domain of Software Engineering, i.e., Information Systems designed to support experience management. Lately, these have become more and more sophisticated from a technical point of view. However, there are several shortcomings that appear to limit the input, the content of these systems and their usage. The problems identified in this paper relate to knowledge acquisition, learning issues, as well as to the users ’ motivation and trust. We introduce an approach meant to enhance the content of the experience base and improve learning from experiences within information spaces, namely weblogs that are maintained during daily work and serve as input for both an experience base and for an information element base. In order to enhance learning, a pedagogical information agent is envisaged for retrieving suitable experiences to be further enriched with additional information elements and produce micro-didactical learning arrangements. In addition we consider the relevance of motivation and trust issues. An empirical study demonstrates that using weblogs for such an approach is feasible. Keywords: Experience-based Information System, wiki, weblog, pedagogical information agent, information space, micro-didactical learning arrangement

One of the main challenges in today’s world of vastly distributed sources of information is to re-combine information sources to provide uniform access. In this work, we propose a distributed data management system that should provide the “glue ” for combining data sources. This system advocates services as a means to access data. New services are defined on demand and the creation of services is supported by a behaviorist approach that incorporates new service ideas provided by the user. Services can be based on data and/or based on the output of existing services. To increase the usability of services in our system we utilize two ontologies to denote relevant metadata. Service ontology structures existing services and helps in discovering services. Parameter ontology structures the parameters used in services and supports the creation of new services. Our proposal of a services-based data management system exhibits similarities to the newsgroup approach in that both “systems ” are examples of semantic search engines based on user interaction. By exploring these similarities and by looking at some statistics of newsgroup user/posting behavior, we validate our services-based approach. 1.

Hiermit versichere ich, dass ich die vorliegende Diplomarbeit selbstständig verfasst habe,

Using the Wikipedia as a corpus, the Link-the-Wiki track, launched by INEX in 2007, aims at producing a standard procedure and metrics for the evaluation of (automated) link discovery at different element levels. In this paper, we describe the preliminary procedure for the assessment, including the topic selection, submission, pooling and evaluation. Related techniques are also presented such as the proposed DTD, submission format, XML element retrieval and the concept of Best Entry Points (BEPs). Due to the task required by LTW, it represents a considerable evaluation challenge. We propose a preliminary procedure of assessment for this stage of the LTW and also discuss the further issues for improvement. Finally, an efficiency measurement is introduced for investigation since the LTW task involves two studies: the selection of document elements that represent the topic of request and the nomination of associated links that can access different levels of the XML document.

Abstract. No algorithm can of course solve the Halting Problem, that is, decide within finite time always correctly whether a given program halts on a certain given input. It might however be able to give correct answers for ‘most ’ instances and thus solve it at least approximately. Whether and how well such approximations are feasible highly depends on the underlying encodings and in particular the Gödelization (programming system) which in practice usually arises from some programming language. We consider BrainF*ck (BF), a simple yet Turing-complete real-world programming language over an eight letter alphabet, and prove that the natural enumeration of its syntactically correct sources codes induces a both efficient and dense Gödelization in the sense of [Jakoby&Schindelhauer’99]. It follows that any algorithm M approximating the Halting Problem for BF errs on at least a constant fraction εM> 0 of all instances of size n for infinitely many n. Next we improve this result by showing that, in every dense Gödelization, this constant lower bound ε to be independent of M; while, the other hand, the Halting Problem does admit approximation up to arbitrary fraction δ> 0byan appropriate algorithm M δ handling instances of size n for infinitely many n. The last two results complement work by [Lynch’74]. 1