WorldCat Identities

Amann, Bernd

Works: 20 works in 24 publications in 3 languages and 65 library holdings
Roles: Author, Opponent, Thesis advisor, Other
Classifications: HD7179, 005.7
Publication Timeline
Most widely held works by Bernd Amann
Die Sozialisierung individueller Risiken : eine Public-Choice Analyse staatlicher Sozialversicherungssysteme by Bernd Amann( Book )

3 editions published in 1993 in German and held by 45 WorldCat member libraries worldwide

Informatique cycle probatoire, cours B7, 1ère partie : systèmes de gestion de bases de données by Michel O Scholl( Book )

2 editions published between 1998 and 1999 in French and held by 2 WorldCat member libraries worldwide

ROSES : Un moteur de requêtes continues pour l'aggrégation de flux RSS à large échelle by Jordi Creus Tomas( Book )

2 editions published in 2012 in English and held by 2 WorldCat member libraries worldwide

RSS and Atom are generally less known than the HTML web format, but they are omnipresent in many modern web applications for publishing highly dynamic web contents. Nowadays, news sites publish thousands of RSS/Atom feeds, often organized into general topics like politics, economy, sports, culture, etc. Weblog and microblogging systems like Twitter use the RSS publication format, and even more general social media like Facebook produce an RSS feed for every user and trending topic. This vast number of continuous data-sources can be accessed by using general-purpose feed aggregator applications like Google Reader, desktop clients like Firefox or Thunderbird and by RSS mash-up applications like Yahoo! pipes, Netvibes or Google News. Today, RSS and Atom feeds represent a huge stream of structured text data which potential is still not fully exploited.In this thesis, we first present ROSES -Really Open Simple and Efficient Syndication-, a data model and continuous query language for RSS/Atom feeds. ROSES allows users to create new personalized feeds from existing real-world feeds through a simple, yet complete, declarative query language and algebra. The ROSES algebra has been implemented in a complete scalable prototype system capable of handling and processing ROSES feed aggregation queries. The query engine has been designed in order to scale in terms of the number of queries. In particular, it implements a new cost-based multi-query optimization approach based on query normalization and shared filter factorization. We propose two different factorization algorithms: (i) STA, an adaption of an existing approximate algorithm for finding minimal directed Steiner trees [CCC+98a], and (ii) VCA, a greedy approximation algorithm based on efficient heuristics outperforming the previous one with respect to optimization cost. Our optimization approach has been validated by extensive experimental evaluation on real world data collections
Système de gestion de bases de données : codes NFP 107 et 107 J : cours et exercices dirigés by Bernd Amann( Book )

1 edition published in 2005 in French and held by 1 WorldCat member library worldwide


1 edition published in 1999 in Undetermined and held by 1 WorldCat member library worldwide

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1 edition published in 2007 in English and held by 1 WorldCat member library worldwide

Informatique cycle probatoire, cours B6 et B7 : systèmes de gestion de bases de données by Michel O Scholl( Book )

1 edition published in 1997 in French and held by 1 WorldCat member library worldwide

Approches hybrides pour la recherche sémantique de l'information : intégration des bases de connaissances et des ressources semi-structurées by Yassine Mrabet( )

1 edition published in 2012 in French and held by 1 WorldCat member library worldwide

Semantic information retrieval has known a rapid development with the new Semantic Web technologies. With these technologies, software can exchange and use data that are written according to domain ontologies describing explicit semantics. This ``semantic'' information access requires the availability of knowledge bases describing both domain ontologies and their instances. The most often, these knowledge bases are constructed automatically by annotating document corpora. However, while these knowledge bases are getting bigger, they still contain much less information when comparing them with the HTML documents available on the surface Web.Thus, semantic information retrieval reaches some limits with respect to ``classic'' information retrieval which exploits these documents at a bigger scale. In practice, these limits consist in the lack of concept and relation instances in the knowledge bases constructed from the same Web documents. In this thesis, we study two research directions in order to answer semantic queries in such cases. The first direction consists in reformulating semantic user queries in order to reach relevant document parts instead of the required (and missing) facts. The second direction that we study is the automatic enrichment of knowledge bases with relation instances.We propose two novel solutions for each of these research directions by exploiting semi-structured documents annotated with concept instances. A key point of these solutions is that they don't require lexico-syntactic or structure regularities in the documents. We position these approaches with respect to the state of the art and experiment them on several real corpora extracted from the Web. The results obtained from bibliographic citations, call-for-papers and geographic corpora show that these solutions allow to retrieve new answers/relation instances from heterogeneous documents and rank them efficiently according to their precision
Informatique : bases de données relationnelles, exercices dirigés by Michel O Scholl( Book )

1 edition published in 2000 in French and held by 1 WorldCat member library worldwide

Informatique cycle B, cours B7 exercices dirigés : systèmes de gestion de bases de données by Michel O Scholl( Book )

1 edition published in 2001 in French and held by 1 WorldCat member library worldwide

Optimisation des requêtes skyline multidimensionnelles by Patrick Kamnang Wanko( )

1 edition published in 2017 in French and held by 1 WorldCat member library worldwide

Dans le cadre de la sélection de meilleurs éléments au sein d'une base de données multidimensionnelle, plusieurs types de requêtes ont été définies. L'opérateur skyline présente l'avantage de ne pas nécessiter la définition d'une fonction de score permettant de classer lesdits éléments. Cependant, la propriété de monotonie que cet opérateur ne présente pas, rend non seulement (i) difficile l'optimisation de ses requêtes dans un contexte multidimensionnel, mais aussi (ii) presque imprévisible la taille du résultat des requêtes. Ce travail se propose, dans un premier temps, d'aborder la question de l'estimation de la taille du résultat d'une requête skyline donnée, en formulant des estimateurs présentant de bonnes propriétés statistiques(sans biais ou convergeant). Ensuite, il fournit deux approches différentes à l'optimisation des requêtes skyline. La première reposant sur un concept classique des bases de données qui est la dépendance fonctionnelle. La seconde se rapprochant des techniques de compression des données. Ces deux techniques trouvent leur place au sein de l'état de l'art comme le confortent les résultats expérimentaux.Nous abordons enfin la question de requêtes skyline au sein de données dynamiques en adaptant l'une de nos solutions précédentes dans cet intérêt
Recherche top-k pour le contenu du Web by Raphaël Bonaque( )

1 edition published in 2016 in English and held by 1 WorldCat member library worldwide

Social networks are increasingly present in our everyday life and are fast becoming our primary means of information and communication. As they contain more and more data about our surrounding and ourselves, it becomes vital to access and analyze this data. Currently, the primary means to query this data is through top-k keyword search: you enter a few words and the social network service sends you back a fixed number of relevant documents. In current top-k searches in a social context the relevance of a document is evaluated based on two factors: the overlapping of the query keywords with the words of the document and the social proximity between the document and the user making the query. We argue that this is limited and propose to take into account the complex interactions between the users linked to the document, its structure and the meaning of the words it contains instead of their phrasing. To this end we highlight the requirements for a model integrating fully structured, semantic and social data and propose a new model, called S3, satisfying these requirements. We introduce querying capabilities to S3 and develop an algorithm, S3k, for customizable top-k keyword search on S3. We prove the correctness of our algorithm and propose an implementation for it. We compare this implementation with another top-k keyword search in a social context, using datasets created from real world data, and show their differences and the benefits of our approach
A Pattern Model and Algebra for Representing and Querying Relative Information Completenes by Fatma-Zohra Hannou( )

1 edition published in 2019 in English and held by 1 WorldCat member library worldwide

L'incomplétude des données est un problème majeur de qualité qui s'amplifie par la quantité croissante de données collectées par des sources peu fiables. L'évaluation de l'exhaustivité des données est cruciale pour déterminer leur qualité mais aussi la validité des réponses de requêtes qui en découlent. Dans le contexte de l'information relative, la complétude d'une base de données est évaluée en comparaison à une base référence. Nous apportons deux principales contributions à ce domaine: un modèle de motifs produisant des couvertures minimales résumant l'étendue des partitions de données complètes et manquantes, ainsi qu'une algèbre de motifs permettant de dériver des couvertures minimales pour l'analyse de la validité des réponses des requêtes. Ce modèle de motifs offre une opportunité intéressante pour réaliser de nombreuses applications, en particulier celles visant à améliorer la qualité des tâches affectées par les données manquantes. Nous adoptons une technique de réécriture de requêtes à base de règles pour imputer les réponses des requêtes d'agrégation manquantes ou présentant des valeurs incorrectes. Nous étudions également la généralisation de notre modèle de motifs pour effectuer la synthèse des fragments de données. Les résumés peuvent être interrogés pour analyser et comparer les fragments de données de manière synthétique et flexible
Evaluation de requêtes top-k continues à large-échelle by Despoina Vouzoukidou( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

In this thesis, we are interested in efficient evaluation techniques of continuous top-k queries over text and feedback streams featuring generalized scoring functions which capture dynamic ranking aspects. As a first contribution, we generalize state of the art continuous top-k query models, by introducing a general family of non-homogeneous scoring functions combining query-independent item importance with query-dependent content relevance and continuous score decay reflecting information freshness. Our second contribution consists in the definition and implementation of efficient in-memory data structures for indexing and evaluating this new family of continuous top-k queries. Our experiments show that our solution is scalable and outperforms other existing state of the art solutions, when restricted to homogeneous functions. Going a step further, in the second part of this thesis we consider the problem of incorporating dynamic feedback signals to the original scoring function and propose a new general real-time query evaluation framework with a family of new algorithms for efficiently processing continuous top-k queries with dynamic feedback scores in a real-time web context. Finally, putting together the outcomes of these works, we present MeowsReader, a real-time news ranking and filtering prototype which illustrates how a general class of continuous top-k queries offers a suitable abstraction for modelling and implementing continuous online information filtering applications combining keyword search and real-time web activity
Améliorer l'interopérabilité sémantique : applicabilité et utilité de l'alignement d'ontologies by Fayçal Hamdi( )

1 edition published in 2011 in French and held by 1 WorldCat member library worldwide

Dans cette thèse, nous présentons des approches d'adaptation d'un processus d'alignement aux caractéristiques des ontologies alignées, qu'il s'agisse de caractéristiques quantitatives telles que leur volume ou de caractéristiques particulières liées par exemple à la façon dont les labels des concepts sont construits. Concernant les caractéristiques quantitatives, nous proposons deux méthodes de partitionnement d'ontologies qui permettent l'alignement des ontologies très volumineuses. Ces deux méthodes génèrent, en entrée du processus d'alignement, des sous ensembles de taille raisonnable des deux ontologies à aligner en prenant en compte dès le départ l'objectif d'alignement dans le processus de partitionnement.Concernant les caractéristiques particulières des ontologies alignées, nous présentons l'environnement TaxoMap Framework qui permet la spécification de traitements de raffinement à partir de primitives prédéfinies. Nous proposons un langage de patrons MPL (the Mapping Pattern Language) que nous utilisons pour spécifier les traitements de raffinement.En plus des approches d'adaptation aux caractéristiques des ontologies alignées, nous présentons des approches de réutilisation des résultats d'alignement pour l'ingénierie ontologique. Nous nous focalisons plus particulièrement sur l'utilisation de l'alignement pour l'enrichissement d'ontologies. Nous étudions l'apport des techniques d'alignement pour l'enrichissement et l'impact des caractéristiques de la ressource externe utilisée comme source d'enrichissement. Enfin, nous présentons la façon dont l'environnement TaxoMap Framework a été implémenté et les expérimentations réalisées : des tests sur le module d'alignement TaxoMap, sur l'approche de raffinement de mappings, sur les méthodes de partitionnement d'ontologies de très grande taille et sur l'approche d'enrichissement d'ontologies
Ingénierie et intégration informatique B7 : systèmes de gestion de bases de données by Michel O Scholl( Book )

1 edition published in 1996 in French and held by 1 WorldCat member library worldwide

Systèmes de gestion de bases de données B7 by Michel O Scholl( Book )

1 edition published in 2000 in French and held by 1 WorldCat member library worldwide

Informatique : cycle B : cours B7 : code 19786 : systèmes de gestion de bases de données by Michel O Scholl( Book )

1 edition published in 2004 in French and held by 1 WorldCat member library worldwide

Informatique cycle B, cours B7, 2eme partie : systèmes de gestion de bases de données by Michel O Scholl( Book )

1 edition published in 2002 in French and held by 1 WorldCat member library worldwide

Die Sozialisierung indivueller Risiken : e. Public-Choice Analyse staatl. Sozialversicherungssysteme by Bernd Amann( Book )

1 edition published in 1993 in Undetermined and held by 0 WorldCat member libraries worldwide

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Audience level: 0.91 (from 0.89 for Die Sozial ... to 1.00 for Die Sozial ...)

French (13)

English (6)

German (3)