Exploiting Hierarchy in Text Categorization

With the recent dramatic increase in electronic access to documents, text categorization—the task of assigning topics to a given document—has moved to the center of the information sciences and knowledge management. This article uses the structure that is present in the semantic space of topics in order to improve performance in text categorization: according to their meaning, topics can be grouped together into meta-topics, e.g., gold, silver, and copper are all metals. The proposed architecture matches the hierarchical structure of the topic space, as opposed to a flat model that ignores the structure. It accommodates both single and multiple topic assignments for each document. Its probabilistic interpretation allows its predictions to be combined in a principled way with information from other sources. The first level of the architecture predicts the probabilities of the meta-topic groups. This allows the individual models for each topic on the second level to focus on finer discriminations within the group. Evaluating the performance of a two-level implementation on the Reuters-22173 testbed of newswire articles shows the most significant improvement for rare classes.     

Interoperabilit?t für Informationssysteme im Gesundheitswesen auf Basis medizinischer Standards

Eine Vernetzung der Dienstleister im Gesundheitswesen wird aus Effizienzgründen immer wichtiger. Schwierigkeiten bereitet jedoch die Interoperabilität, womit die korrekte Kommunikation von beteiligten Softwaresystemen verschiedener Herkunft gemeint ist. Dieser Beitrag konzentriert sich auf die Interoperabilitätsproblematik auf der Ebene der Anwendungsarchitekturen. Mit Hilfe von Standards und Integrationstechniken bemühen sich verschiedene Lösungsansätze die Heterogenität zu überwinden, die einer umfassenden Interoperabilität im Wege steht. Die Frage, die sich uns in diesem Zusammenhang nun stellt ist, ob diverse Standards im Gesundheitswesen sinnvoll kombiniert werden können bzw. zwischen ihnen vermittelt werden kann. In diesem Artikel stellen wir die Grundzüge einer Architektur vor, die auf der Basis von Standards eine institutionsübergreifende Interoperabilität im Gesundheitswesen ermöglichen soll. Die Strukturen der relevanten Standards werden einheitlich als Instanzen des Meta-Object Facility (MOF) spezifiziert und dann geeignet zueinander in Beziehung gesetzt. Die resultierenden Modelle und Metamodelle bilden einen Leitfaden zur Strukturanalyse der Standards und helfen so beim Entwurf der Transformationen zwischen den verschiedenen Standards. Architektur und Metamodelle dienen als Grundlage für eine prototypische Implementierung am Beispiel des Epidemiologischen Krebsregisters Niedersachsen zur Evaluation des vorgestellten Konzeptes.     

Competitive Research Grants and Their Impact on Career Performance

The role of competitive funds as a source of funding for academic research has increased in many countries. For the individual researcher, the receipt of a grant can influence both scientific production and career paths. This paper focuses on the importance of the receipt of a research grant for researchers’ academic career paths utilizing a mixed methods approach that combines econometric analysis with in-depth qualitative interviews. The analysis has novel elements both in terms of its subject (impact of funding grants on individuals’ academic career paths) and approach. The results of this study indicate that while research grants have a positive impact on the research performed under the grant itself, there are very important secondary effects on research performance through positive effects on academic career advancement. The probability of obtaining a full professorship for grant recipients is almost double that for rejected applicants, 16 percent compared to 9 percent. The probability for career advancement in general is about 9 percentage points higher for grant recipients. Qualitative interviews support these quantitative results by providing insights into how grants impact research careers, through heightened status, recognition, networking and other factors.     

Knowledge flows through informal contacts in industrial clusters: myth or reality?

The role of informal networks in the development of regional clusters has recently received a lot of attention in the literature. Informal contact between employees in different firms is claimed to be one of the main carriers of knowledge between firms in a cluster. This paper examines empirically the role of informal contacts in a specific cluster. In a questionnaire survey, we asked a sample of engineers in a regional cluster of wireless communication firms in Northern Denmark a series of questions on informal networks. We analyze whether the engineers actually acquire valuable knowledge through these networks. We find that the engineers do share even quite valuable knowledge with informal contacts. This shows that informal contacts represent an important channel of knowledge diffusion.