8 research outputs found
Онтології у контексті інтеграції інформації: представлення, методи та інструменти побудови
У даному огляді розглядається використання онтологій для підтримки задач інтеграції в
семантично гетерогенних інформаційних системах. Представлені основні поняття та визначення
онтологій, причини та приклади побудови. Розглядаються моделі і мови для представлення онтологій
та використання відображень між ними. Досліджуються методи й інструментальні засоби для інженерії
онтологій і підтримки інтеграції інформації. Також наводяться приклади візуалізації, побудови та
злиття двох онтологій за допомогою сучасних інструментів
Benchmarking Bottom-Up and Top-Down Strategies to Sparql-To-Sql Query Translation
Many researchers have proposed using conventional relational databases to store and query large Semantic Web datasets. The most complex component of this approach is SPARQL-to-SQL query translation. Existing algorithms perform this translation using either bottom-up or top-down strategy and result in semantically equivalent but syntactically different relational queries. Do relational query optimizers always produce identical query execution plans for semantically equivalent bottom-up and top-down queries? Which of the two strategies yields faster SQL queries? To address these questions, this work studies bottom-up and top-down translations of SPARQL queries with nested optional graph patterns. This work presents: (1) A basic graph pattern translation algorithm that yields flat SQL queries, (2) A bottom-up nested optional graph pattern translation algorithm, (3) A top-down nested optional graph pattern translation algorithm, and (4) A performance study featuring SPARQL queries with nested optional graph patterns over RDF databases created in Oracle, DB2, and PostgreSQL
S2ST: A Relational RDF Database Management System
The explosive growth of RDF data on the Semantic Web drives the need for novel database systems that can efficiently store and query large RDF datasets. To achieve good performance and scalability of query processing, most existing RDF storage systems use a relational database management system as a backend to manage RDF data. In this paper, we describe the design and implementation of a Relational RDF Database Management System. Our main research contributions are: (1) We propose a formal model of a Relational RDF Database Management System (RRDBMS), (2) We propose generic algorithms for schema, data and query mapping, (3) We implement the first and only RRDBMS, S2ST, that supports multiple relational database management systems, user-customizable schema mapping, schema-independent data mapping, and semantics-preserving query translation
Knowledge-Based Task Structure Planning for an Information Gathering Agent
An effective solution to model and apply planning domain knowledge for deliberation and action in probabilistic, agent-oriented control is presented. Specifically, the addition of a task structure planning component and supporting components to an agent-oriented architecture and agent implementation is described. For agent control in risky or uncertain environments, an approach and method of goal reduction to task plan sets and schedules of action is presented. Additionally, some issues related to component-wise, situation-dependent control of a task planning agent that schedules its tasks separately from planning them are motivated and discussed
Organización de la información mediante el uso de lenguajes de modelado : viejos recursos para nuevas necesidades
First, the context in which the need to develop an ontology appears is defined. Then, we discuss the concepts of “model” and ”ontology”, and justify our bet for an intensional concept. In the same way, we discuss the differences between ontologies design and business processes re-engineering. Finally, the IDEF5 method and languages to create ontologies are explained in a more detailed way, refering to some examples of associated softwarePrimero, se establece el contexto en el que nace la necesidad de elaborar una ontología. Después, se discuten los conceptos de modelo y de ontología, y se justifica la selección de un concepto intensional. Se discute de igual modo la diferencia entre el diseño de ontologías y la reingeniería de procesos. Finalmentelican con más detalle el método y los lenguajes IDEF5 para la creación de ontologías. Se refieren algunos ejemplos de software relevante. (a
Exploitation dynamique des données de production pour améliorer les méthodes DFM dans l'industrie Microélectronique
La conception pour la fabrication ou DFM (Design for Manufacturing) est une méthode maintenant classique pour assurer lors de la conception des produits simultanément la faisabilité, la qualité et le rendement de la production. Dans l'industrie microélectronique, le Design Rule Manual (DRM) a bien fonctionné jusqu'à la technologie 250nm avec la prise en compte des variations systématiques dans les règles et/ou des modèles basés sur l'analyse des causes profondes, mais au-delà de cette technologie, des limites ont été atteintes en raison de l'incapacité à sasir les corrélations entre variations spatiales. D'autre part, l'évolution rapide des produits et des technologies contraint à une mise à jour dynamique des DRM en fonction des améliorations trouvées dans les fabs. Dans ce contexte les contributions de thèse sont (i) une définition interdisciplinaire des AMDEC et analyse de risques pour contribuer aux défis du DFM dynamique, (ii) un modèle MAM (mapping and alignment model) de localisation spatiale pour les données de tests, (iii) un référentiel de données basé sur une ontologie ROMMII (referential ontology Meta model for information integration) pour effectuer le mapping entre des données hétérogènes issues de sources variées et (iv) un modèle SPM (spatial positioning model) qui vise à intégrer les facteurs spatiaux dans les méthodes DFM de la microélectronique, pour effectuer une analyse précise et la modélisation des variations spatiales basées sur l'exploitation dynamique des données de fabrication avec des volumétries importantes.The DFM (design for manufacturing) methods are used during technology alignment and adoption processes in the semiconductor industry (SI) for manufacturability and yield assessments. These methods have worked well till 250nm technology for the transformation of systematic variations into rules and/or models based on the single-source data analyses, but beyond this technology they have turned into ineffective R&D efforts. The reason for this is our inability to capture newly emerging spatial variations. It has led an exponential increase in technology lead times and costs that must be addressed; hence, objectively in this thesis we are focused on identifying and removing causes associated with the DFM ineffectiveness. The fabless, foundry and traditional integrated device manufacturer (IDM) business models are first analyzed to see coherence against a recent shift in business objectives from time-to-market (T2M) and time-to-volume towards (T2V) towards ramp-up rate. The increasing technology lead times and costs are identified as a big challenge in achieving quick ramp-up rates; hence, an extended IDM (e-IDM) business model is proposed to support quick ramp-up rates which is based on improving the DFM ineffectiveness followed by its smooth integration. We have found (i) single-source analyses and (ii) inability to exploit huge manufacturing data volumes as core limiting factors (failure modes) towards DFM ineffectiveness during technology alignment and adoption efforts within an IDM. The causes for single-source root cause analysis are identified as the (i) varying metrology reference frames and (ii) test structures orientations that require wafer rotation prior to the measurements, resulting in varying metrology coordinates (die/site level mismatches). A generic coordinates mapping and alignment model (MAM) is proposed to remove these die/site level mismatches, however to accurately capture the emerging spatial variations, we have proposed a spatial positioning model (SPM) to perform multi-source parametric correlation based on the shortest distance between respective test structures used to measure the parameters. The (i) unstructured model evolution, (ii) ontology issues and (iii) missing links among production databases are found as causes towards our inability to exploit huge manufacturing data volumes. The ROMMII (referential ontology Meta model for information integration) framework is then proposed to remove these issues and enable the dynamic and efficient multi-source root cause analyses. An interdisciplinary failure mode effect analysis (i-FMEA) methodology is also proposed to find cyclic failure modes and causes across the business functions which require generic solutions rather than operational fixes for improvement. The proposed e-IDM, MAM, SPM, and ROMMII framework results in accurate analysis and modeling of emerging spatial variations based on dynamic exploitation of the huge manufacturing data volumes.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF
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HealthCyberMap: Mapping the Health Cyberspace Using Hypermedia GIS and Clinical Codes
HealthCyberMap () is a Semantic Web service for healthcare professionals and librarians, patients and the public m general that aims at mappmg parts of medical/ health information resources in cyberspace in novel ways to improve their retrieval and navigation. The Semantic Web ( and ) aims to be the next-generation World Wide Web by giving machine-readable semantics and context to the currently presentation-based Web pages. HealthCyberMap features an unconventional use of GIS (Geographic Information Systems) to map conceptual spaces occupied by collections of medical/ health information resources. Besides mapping the semantic and non-geographical aspects of these resources using suitable spatial metaphors, HealthCyberMap also collects and maps the geographical provenance of these resources. Some of HealthCyberMap Web interfaces are visual (maps for browsing resources by clinical/ health topic, by provenance and by type), while others are textual (multilingual interfaces for browsing resources by language, and a directory of topical resource categories, besides HealthCyberMap Semantic Subject Search Engine that goes beyond conventional free-text and keyword-based search engines, and supports synonyms, disease variants, subtypes, as well as some semantic relationships between terms).
HealthCyberMap adopts a clinical metadata framework built upon a clinical coding scheme (vocabulary or ontology—ICD-9-CM* clinical classification in the current pilot service). Clinical coding schemes serve as a reliable common backbone for topical resource indexing, automated topical classification, topical visualisation and navigation of coded resource pools (using suitable metaphors), and enhanced information retrieval and linking. A resource metadata base based on Dublin Core metadata set with HealthCyberMap’s own extensions holds information about selected high-quality resources. HealthCyberMap then uses GIS spatialisation methods to generate interactive navigational cybermaps from the metadata base. These visual cybermaps are based on familiar metaphors for image-word association to give users a broad overview and understanding of what is available in this complex conceptual space of medical/ health Internet resources and help them navigate it more efficiently and effectively.
HealthCyberMap cybermaps can be considered as semantically-spatialised, ontology-based browsing views of the underlying resource metadata base. Using a clinical coding scheme as a metric for spatialisation (“semantic distance”) is unique to HealthCyberMap and is very much suited for the semantic categorisation and navigation of medical/ health Internet information resources. HealthCyberMap also introduces a useful form of cyberspatial analysis for the detection of topical coverage gaps in its resource pool using choropleth (shaded) maps of human body systems. The project features a cost-effective method for serving Web hypermaps with dynamic metadata base drill-down functionality. It also demonstrates the feasibility of Electronic Patient Record to Online Information Services (like HealthCyberMap) Problem to Knowledge Linking using clinical codes as crisp problem-knowledge linkers or knowledge hooks.
The Semantic Subject Search Engine queries the same HealthCyberMap resource metadata base. Explicit concepts in resource metadata map onto a brokering domain ontology (ICD-9-CM) allowing the search engine to infer implicit meanings (synonyms and semantic relationships) not directly mentioned in either the resource or its metadata. Similarly, user queries would map to the same ontology allowing the search engine to infer the implicit semantics of user queries and use them to optimise retrieval.
A formative evaluation study of HealthCyberMap pilot service using an online user evaluation questionnaire, in addition to analysis of HealthCyberMap server transaction log, has been conducted during the period from 18 April 2002 to 1 June 2002 with very encouraging results. This two-method evaluation approach was guided by methodologies described in NIH Web Site Evaluation and Performance Measures Toolkit among other resources.
Many exciting future possibilities have been also investigated by the author, including the further development of HealthCyberMap as a customisable, location-based medical/ health information service
Efficient Management of Very Large Ontologies
This paper describes an environment for supporting very large ontologies. The system can be used on single PCs, workstations, a cluster of workstations, and high-end parallel supercomputers. The architecture of the system uses the secondary storage of a relational data base system, efficient memory management, and (optionally) parallelism. This allows us to answer complex queries in very large ontologies in a few seconds on a single processor machine and in fractions of a second on parallel super computers. The main contribution of our approach is the open architecture of the system on both the hardware and the software levels allowing us easily to translate existing ontologies for our system's use, and to port the system to a wide range of platforms. Introduction Ontologies have been a part of research in AI for a long time, for example, ontology-based thesauri have been an important part of research in Natural Language Processing. In the last few years, however, ontologies have beco..