University of Hildesheim
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Semantic Network Analysis of Ontologies
No full textA key argument for modeling knowledge in ontologies is the easy re-use and re-engineering of the knowledge. However, current ontology engineering tools provide only basic functionalities for analyzing ontologies. Since ontologies can be considered as graphs, graph analysis techniques are a suitable answer for this need. Graph analysis has been performed by sociologists for over 60 years, and resulted in the vivid research area of Social Network Analysis (SNA). While social network structures currently receive high attention in the Semantic Web community, there are only very few SNA applications, and virtually none for analyzing the structure of ontologies. We illustrate the benefits of applying SNA to ontologies and the Semantic Web, and discuss which research topics arise on the edge between the two areas. In particular, we discuss how different notions of centrality describe the core content and structure of an ontology. From the rather simple notion of degree centrality over betweenness centrality to the more complex eigenvector centrality, we illustrate the insights these measures provide on two ontologies, which are different in purpose, scope, and size
Pairwise Naive Bayes Classifier
No full textClass binarizations are effective methods that break multi-class problem down into several 2-class or binary problems to improve weak learners. This paper analyzes which effects these methods have if we choose a Naive Bayes learner for the base classifier. We consider the known unordered and pairwise class binarizations and propose an alternative approach for a pairwise calculation of a modified Naive Bayes classifier
Personal Reader Agent: Personalized Access to ConfigurableWeb Services
No full textThe Personal Reader Framework enables the design, realization and maintenance of personalized Web Content Reader. In this architecture personalized access to web content is realized by various Web Services - we call them Personalization Services. With our new approach of Configurable Web Services we allow users to configure these Personalization Services. Such configurations can be stored and reused at a later time. The interface between Users and Configurable Web Services is realized in a Personal Reader Agent. This Agent allows selection, configuration and calling of the Web Services and further provides personalization functionalities like reuse of stored configurations which suit the users interests
Ansätze zur Bestimmung von Locality für deutsche Webseiten
No full textDas geographische Information Retrieval (GeoIR) berücksichtigt bei Suchanfragen – insb. nach Webseiten – neben dem Inhalt von Dokumenten auch eine räumliche Komponente, um gezielt nach Seiten suchen zu können, die für eine spezifische Region bedeutsam sind. Dazu müssen GeoIR-Systeme den geographischen Kontext einer Webseite erkennen können und in der Lage sein zu entscheiden, ob eine Seite überhaupt regional-spezifisch ("lokal") ist oder einen rein informativen Charakter besitzt, der keinen geographischen Bezug besitzt. Im Folgenden werden Ansätze vorgestellt, Merkmale lokaler Seiten zu ermitteln und diese für eine Einteilung von Webseiten in globale und lokale Seiten zu verwenden. Dabei sollen insbesondere die sprachlichen und geographischen Eigenschaften deutscher Webseiten berücksichtigt werden
Pattern recognition of gene expression data on biochemical networks with simple wavelet transforms
No full textBiological networks show a rather complex, scale-free topology consisting of few highly connected (hubs) and many low connected (peripheric and concatenating) nodes. Furthermore, they contain regions of rather high connectivity, as in e.g. metabolic pathways. To analyse data for an entire network consisting of several thousands of nodes and vertices is not manageable. This inspired us to divide the network into functionally coherent sub-graphs and analysing the data that correspond to each of these sub-graphs individually. We separated the network in a two-fold way: 1. clustering approach: sub-graphs were defined by higher connected regions using a clustering procedure on the network; and 2. connected edge approach: paths of concatenated edges connecting striking combinations of the data were selected and taken as sub-graphs for further analysis. As experimental data we used gene expression data of the bacterium Escherichia coli which was exposed to two distinctive environments: oxygen rich and oxygen deprived. We mapped the data onto the corresponding biochemical network and extracted disciminating features using Haar wavelet transforms for both strategies. In comparison to standard methods, our approaches yielded a much more consistent image of the changed regulation in the cells. In general, our concept may be transferred to network analyses on any interaction data, when data for two comparable states of the associated nodes are made available
From Personal Memories to Sharable Memories
No full textThe exchange of personal experiences is a way of supporting decision making and interpersonal communication. In this article, we discuss how augmented personal memories could be exploited in order to support such a sharing. We start with a brief summary of a system implementing an augmented memory for a single user. Then, we exploit results from interviews to define an example scenario involving sharable memories. This scenario serves as background for a discussion of various questions related to sharing memories and potential approaches to their solution. We especially focus on the selection of relevant experiences and sharing partners, sharing methods, and the configuration of those sharing methods by means of reflection
GeoCLEF 2006: Cross-linguales geographisches Information Retrieval
No full textDer speziellen Behandlung geographischer Suchanfragen wird im Information Retrieval zunehmend mehr Beachtung geschenkt. So gibt der vorliegende Artikel einen Überblick über aktuelle Forschungsaktivitäten und zentrale Problemstellungen im Bereich des geographischen Information Retrieval, wobei speziell auf das Projekt GeoCLEF im Rahmen der crosslingualen Evaluierungsinitiative CLEF eingegangen wird. Die Informationswissenschaft der Universität Hildesheim hat in diesem Projekt sowohl organisatorische Aufgaben wahrgenommen als auch eigene Experimente durchgeführt. Dabei wurden die Aspekte der Verknüpfung von Gewichtungsansätzen mit Booleschem Retrieval sowie die Gewichtung von geographischen Eigennamen fokussiert. Anhand erster Interpretationen der Ergebnisse und Erfahrungen werden weiterer Forschungsbedarf und zukünftige, eigene Vorhaben wie die Überprüfung von Heuristiken zur Query-Expansion aufgezeigt
Die Suchmaschine SENTRAX : Grundlagen und Anwendungen dieser Neuentwicklung
No full textThis article introduces an automatic "essence-extractor-engine" which works both on structured and inhomogenous document collections and supports interactive searching.Es wird eine intelligente Suchmaschine für den bequemen Zugriff auf strukturierte und unstrukturierte Informationen vorgestellt. Grundlage bilden 4 verschiedene Ähnlichkeitsmaße auf den Datensorten in der Datenbasis gemäß den jeweiligen Aufgaben: Schreibweisentolerante Suche, Kontextähnliche Suche, Zugriff auf Dokumententreffer, Doublettensuche
Crime Pattern Detection Using Data Mining
No full textCan crimes be modeled as data mining problems? We will try to answer this question in this paper. Crimes are a social nuisance and cost our society dearly in several ways. Any research that can help in solving crimes faster will pay for itself. Here we look at use of clustering algorithm for a data mining approach to help detect the crimes patterns and speed up the process of solving crime. We will look at k-means clustering with some enhancements to aid in the process of identification of crime patterns. We will apply these techniques to real crime data from a sheriff’s office and validate our results. We also use semi-supervised learning technique here for knowledge discovery from the crime records and to help increase the predictive accuracy. We also developed a weighting scheme for attributes here to deal with limitations of various out of the box clustering tools and techniques. This easy to implement machine learning framework works with the geo-spatial plot of crime and helps to improve the productivity of the detectives and other law enforcement officers. It can also be applied for counter terrorism for homeland security
Aspekte des Qualitätsmanagements bei der Implementierung einer Suchmaschine
No full textIn diesem Aufsatz soll die geplante Implementierung von Suchmaschinentechnologien im Fachportal Pädagogik zum Anlass genommen werden, um sich mit den damit verbundenen neuen Anforderungen an ein Qualitätsmanagement auseinanderzusetzen. Im Zentrum stehen die Fragen, welche Zusammenhänge die Recherche- Situationen formen und welche Schlussfolgerungen sich daraus für ein Evaluationsdesign ergeben. Als analytisches Instrumentarium soll dabei eine soziotechnische Sichtweise auf das Information- Retrieval-System (IR) dienen