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Composition and Inversion of Schema Mappings  [PDF]
Marcelo Arenas,Jorge Perez,Juan Reutter,Cristian Riveros
Computer Science , 2009,
Abstract: In the recent years, a lot of attention has been paid to the development of solid foundations for the composition and inversion of schema mappings. In this paper, we review the proposals for the semantics of these crucial operators. For each of these proposals, we concentrate on the three following problems: the definition of the semantics of the operator, the language needed to express the operator, and the algorithmic issues associated to the problem of computing the operator. It should be pointed out that we primarily consider the formalization of schema mappings introduced in the work on data exchange. In particular, when studying the problem of computing the composition and inverse of a schema mapping, we will be mostly interested in computing these operators for mappings specified by source-to-target tuple-generating dependencies.
Extended P-Schema and Its Implementation in Mapping from XML Schema to Relational Schema
扩展P-Schema及其在XML Schema到关系模式映射中的应用*

MAO Yu-jie,GU Ming,

计算机应用研究 , 2005,
Abstract: According to the limitedness of P-Schema in the mapping from XML schema to relational schema,this paper brings forward extended P-Schema and presents a mapping method from XML schema to relational schema based on the extended P-Schema. The method brings forward solutions to some difficult problems such as multi-value mapping,recursion mapping,constraints mapping about key and uniqueness,etc.
An XML transfer schema for exchange of genomic and genetic mapping data: implementation as a web service in a Taverna workflow
Trevor Paterson, Andy Law
BMC Bioinformatics , 2009, DOI: 10.1186/1471-2105-10-252
Abstract: We have developed a simple generic XML schema (GenomicMappingData.xsd – GMD) to allow export and exchange of mapping data in a common lightweight XML document format. This schema represents the various types of data objects commonly described across mapping datasources and provides a mechanism for recording relationships between data objects. The schema is sufficiently generic to allow representation of any map type (for example genetic linkage maps, radiation hybrid maps, sequence maps and physical maps). It also provides mechanisms for recording data provenance and for cross referencing external datasources (including for example ENSEMBL, PubMed and Genbank.). The schema is extensible via the inclusion of additional datatypes, which can be achieved by importing further schemas, e.g. a schema defining relationship types. We have built demonstration web services that export data from our ArkDB database according to the GMD schema, facilitating the integration of data retrieval into Taverna workflows.The data exchange standard we present here provides a useful generic format for transfer and integration of genomic and genetic mapping data. The extensibility of our schema allows for inclusion of additional data and provides a mechanism for typing mapping objects via third party standards. Web services retrieving GMD-compliant mapping data demonstrate that use of this exchange standard provides a practical mechanism for achieving data integration, by facilitating syntactically and semantically-controlled access to the data.Data integration across disparate datasources is a common problem, not limited to the sphere of bioinformatics, and has been addressed in many ways [1,2]. Cross indexing and hypertext linking of resources has historically been used for accessing bioinformatics data (e.g. SRS [3]) but is curation intensive and does not adequately address different datatypes found in the distributed datasources. However, cross referencing is widely used and forms the b
S_Schema and it''''s Relation-Based Mapping Method

You ZhongSheng,

计算机科学 , 2005,
Abstract: According to the XML Schema specification published recently by W3C, this paper presents a data model named S_Schema that is equivalent to XML Schema. At the same time, the mapping algorithm from S_Schema to relational Schema and the loading algorithm from XML document to relational database are completed in this paper. By experiment, it proves that S_Schema mapping is better than other methods such as TEXT and Xparent on information maintaining and data querying and updating.
The Schema Mapping Technology in the Integration of Heterogeneous Data Source

YANG Xue-Mei,DONG Yi-Sheng,WANG Yong-Li,QIAN Jiang-Bo,QIAN Gang,

计算机科学 , 2006,
Abstract: Schema mapping is the key technology for the implementation of query reformulation in heterogeneous data source integration. First, centralized and uncentralized integration architecture of schema mapping are introduced, and then three basic forms of schema mapping are summarized, such as GAV, LAV, GLAV. Two core technologies of schema mapping, schema matching and mapping generation, are deeply discussed. Finally, new research issues of schema mapping technology are also mentioned.
Schema Mapping Based on Semantic Similarity of Data Instances Sets

LI Rong-rong,WANG Hui,CHEN Ran,

计算机科学 , 2011,
Abstract: Schema mapping, as the important issue in Web integrated information management and application, has been widely concerned and researched in recent years. Most schema mapping methods have been implemented based on schema information,and schema mapping methods based on data instances are rare. There are many cases in which schema information is insufficient or conflict, and incorrect schema mapping method may be got. In order to improve the performance of schema mapping,a measure was proposed to evaluate semantic similarity between attributes,also the semantic difference between two semantic similarattributes in the same schema was analyzed. Further, a mapping approach based on weighted bipartite was proposed. hhe mapping method proposed was evaluated with experiments and was verified to be efficient and effective to obtain the more complete and accurate schema mapping in situations where schema information is incomplete or conflicting.
Mechanism of Indirect Taxation in Ukraine: Establishment and Development Механизм непрямого налогообложения в Украине: становление и развитие  [PDF]
Pasechnyy Nikolay D.
Business Inform , 2013,
Abstract: The article conducts analysis of foreign experience of the role of indirect taxes in formation of the revenue part of the budget, reveals tendencies of development of indirect taxation in the end of XIX – ХХ centuries, identifies specific features of establishment and development of the domestic mechanism of indirect taxation under conditions of economic transformations and performs assessment of fiscal efficiency of indirect taxes. It reveals approaches to institutional foundations of establishment of the mechanism of indirect taxation, identifies main factors that influence the level of indirect tax proceeds and effectiveness of the budget and taxation policy. It analyses the structure of value added tax proceeds in the context of types of economic activity and excise tax in the context of groups of excisable goods. It identifies priority directions of the taxation system development in the sphere of indirect taxes. В статье проведен анализ зарубежного опыта роли косвенных налогов в формировании доходной части бюджета, выявлены тенденции развития косвенного налогообложения в конце XIX – ХХ вв., определены особенности становления и развития отечественного механизма косвенного налогообложения в условиях экономических преобразований, осуществлена оценка фискальной эффективности косвенных налогов. Раскрыты подходы к институциональным основам становления механизма косвенного налогообложения, определены основные факторы, которые влияют на уровень косвенных налоговых поступлений, результативность бюджетно-налоговой политики. Проанализирована структура поступлений налога на добавленную стоимость в разрезе видов экономической деятельности, акцизного налога в разрезе групп подакцизных товаров. Определены приоритетные направления развития налоговой системы в сфере косвенных налогов.
The SPARQL2XQuery Interoperability Framework. Utilizing Schema Mapping, Schema Transformation and Query Translation to Integrate XML and the Semantic Web  [PDF]
Nikos Bikakis,Chrisa Tsinaraki,Ioannis Stavrakantonakis,Nektarios Gioldasis,Stavros Christodoulakis
Computer Science , 2013,
Abstract: The Web of Data is an open environment consisting of a great number of large inter-linked RDF datasets from various domains. In this environment, organizations and companies adopt the Linked Data practices utilizing Semantic Web (SW) technologies, in order to publish their data and offer SPARQL endpoints (i.e., SPARQL-based search services). On the other hand, the dominant standard for information exchange in the Web today is XML. The SW and XML worlds and their developed infrastructures are based on different data models, semantics and query languages. Thus, it is crucial to develop interoperability mechanisms that allow the Web of Data users to access XML datasets, using SPARQL, from their own working environments. It is unrealistic to expect that all the existing legacy data (e.g., Relational, XML, etc.) will be transformed into SW data. Therefore, publishing legacy data as Linked Data and providing SPARQL endpoints over them has become a major research challenge. In this direction, we introduce the SPARQL2XQuery Framework which creates an interoperable environment, where SPARQL queries are automatically translated to XQuery queries, in order to access XML data across the Web. The SPARQL2XQuery Framework provides a mapping model for the expression of OWL-RDF/S to XML Schema mappings as well as a method for SPARQL to XQuery translation. To this end, our Framework supports both manual and automatic mapping specification between ontologies and XML Schemas. In the automatic mapping specification scenario, the SPARQL2XQuery exploits the XS2OWL component which transforms XML Schemas into OWL ontologies. Finally, extensive experiments have been conducted in order to evaluate the schema transformation, mapping generation, query translation and query evaluation efficiency, using both real and synthetic datasets.
Two-Dimensional Mechanism Design and Implementability by an Indirect Mechanism  [PDF]
Naoki Kojima
Theoretical Economics Letters (TEL) , 2017, DOI: 10.4236/tel.2017.76107
Abstract: This paper studies the problem on two-dimensional mechanism design where the buyer’s taste and budget are his private information. The paper investigates the problem by the method of dimension-reduction, i.e., by focusing only on the buyer’s budget and constructing an indirect mechanism: function of one variable, the buyer’s budget. It is an approach quite antipodal to that by Kojima [1] where he focused on the buyer’s taste instead of his budget. It is shown that the seller does not lose any money by adopting the indirect mechanism of this paper. In other words, the seller’s revenue-maximizing direct mechanism is implemented by such an indirect mechanism
A Query Discovery Algorithm Based on Schema Mapping

LI You,LIU Dong-Bo,ZHANG Wei-Ming,

计算机科学 , 2006,
Abstract: With the rapid development of Internet, integration of diverse data sources becomes a more and more important issue. However,it is a difficult problem due to heterogeneous data structure and semantics of these data sources. This paper introduces a query discovery algorithm based on schema mapping. It can automatically construct query plans according to the target queries and data source schema by exploiting the mappings among data sources. It also guarantees that the target result satisfies the target structure and reference constraints.
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