排序方式: 共有35条查询结果,搜索用时 15 毫秒
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Ben Said Ahmed Erradi Abdelkarim Neiat Azadeh Ghari Bouguettaya Athman 《Mobile Networks and Applications》2019,24(3):1120-1133
Mobile Networks and Applications - This papers presents a deep learning-based framework to predict crowdsourced service availability spatially and temporally. A novel two-stage prediction model is... 相似文献
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T.‐S. Kang B.S. Harrison M. Bouguettaya T.J. Foley J.M. Boncella K.S. Schanze J.R. Reynolds 《Advanced functional materials》2003,13(3):205-210
Near‐infrared‐emitting electroluminescent (EL) devices using blue‐light‐emitting polymers blended with the Yb complexes Yb(DBM)3phen (DBM = dibenzoylmethane), Yb(DNM)3phen (DNM = dinaphthoylmethane), and Yb(TPP)L(OEt) (L(OEt) = [(C5H5)Co{P(O)Et2}3]–) have been studied. EL devices composed of Yb(DNM)3phen blended with PPP‐OR11 showed enhanced near‐IR output at 977 nm when compared to those fabricated with Yb(DBM)3phen/PPP‐OR11 blends. The maximum near‐IR external efficiencies of the devices with Yb(DBM)3phen and Yb(DNM)3phen are, respectively, 7 × 10–5 (at 6 V and at 0.81 mA mm–2) and 4 × 10–4 (at 7 V, and 0.74 mA mm–2). The optimal blend composition for EL device performance consisted of PPP‐OR11 blended with 10–20 mol‐% Yb(DNM)3phen. A device fabricated using Yb‐(TPP)L(OEt)/PPP‐OR11 showed significantly enhanced near‐IR output efficiency, and future efforts will focus on devices fabricated using porphyrin‐based materials. 相似文献
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The Web offers a single user interface to data sharing across heterogeneous and autonomous databases, but it was not designed to handle the rigid DBMS protocols and data formats used by relational and object-oriented databases. WebFindIt is an ongoing project to develop the database equivalent of the World Wide Web-namely, a World Wide Database-through a middleware infrastructure for describing, locating, and accessing data from any kind of Web-accessible database. A special-purpose language, Web-Tassili, supports the definition and manipulation of middleware constructs for organizing the information space. An implementation of WebFindIt combines Java, CORBA and database technologies 相似文献
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A two-phase framework for quality-aware Web service selection 总被引:1,自引:0,他引:1
Qi Yu Manjeet Rege Athman Bouguettaya Brahim Medjahed Mourad Ouzzani 《Service Oriented Computing and Applications》2010,4(2):63-79
Service-oriented computing is gaining momentum as the next technological tool to leverage the huge investments in Web application
development. The expected large number of Web services poses a set of new challenges for efficiently accessing these services.
We propose an integrated service query framework that facilitates users in accessing their desired services. The framework
incorporates a service query model and a two-phase optimization strategy. The query model defines service communities that
are used to organize the large and heterogeneous service space. The service communities allow users to use declarative queries
to retrieve their desired services without worrying about the underlying technical details. The two-phase optimization strategy
automatically generates feasible service execution plans and selects the plan with the best user-desired quality. In particular,
we present an evolutionary algorithm that is able to “co-evolve” multiple feasible execution plans simultaneously and allows
them to compete with each other to generate the best plan. We conduct a set of experiments to assess the performance of the
proposed algorithms. 相似文献
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Query Processing and Optimization on the Web 总被引:2,自引:0,他引:2
The advent of the Internet and the Web and their subsequent ubiquity have brought forth opportunities to connect information sources across all types of boundaries (local, regional, organizational, etc.). Examples of such information sources include databases, XML documents, and other unstructured sources. Uniformly querying those information sources has been extensively investigated. A major challenge relates to query optimization. Indeed, querying multiple information sources scattered on the Web raises several barriers for achieving efficiency. This is due to the characteristics of Web information sources that include volatility, heterogeneity, and autonomy. Those characteristics impede a straightforward application of classical query optimization techniques. They add new dimensions to the optimization problem such as the choice of objective function, selection of relevant information sources, limited query capabilities, and unpredictable events. In this paper, we survey the current research on fundamental problems to efficiently process queries over Web data integration systems. We also outline a classification for optimization techniques and a framework for evaluating them. 相似文献
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Brahim?MedjahedEmail author Athman?BouguettayaEmail author 《Distributed and Parallel Databases》2005,17(2):179-206
The combination of Web services and ontologies is gaining momentum as the potential silver bullets for tomorrows Web, i.e., the Semantic Web. We propose an architectural foundation for managing semantic Web services in dynamic environments. We introduce the concept of community to cater for an ontological organization of Web services. We develop an ontology called community ontology that serves as a template for describing communities of Web services. We also propose a peer-to-peer approach for managing communities in dynamic environments. 相似文献
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M-services provide mobile users wireless access to Web services. In this paper, we present a novel infrastructure for supporting M-services in wireless broadcast systems. The proposed infrastructure provides a generic framework for mobile users to look up, access, and execute Web services over wireless broadcast channels. Access efficiency is an important issue in wireless broadcast systems. We discuss different semantics that have impact on the access efficiency for composite M-services. A multiprocess workflow is proposed for effectively accessing composite M-services from multiple broadcast channels based on these semantics. We also present and compare different broadcast channel organizations for M-services and wireless data. Analytical models are provided for these channel organizations. Practical studies are presented to demonstrate the impact of different semantics and channel organizations on the access efficiency. 相似文献
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An aspect-oriented programming (AOP) based approach is proposed to perform context-aware service composition on the fly. It realises context-aware composition by semantically weaving context into Web service composition. The context weaver algorithm is implemented and illustrated. The proposed semantic weaving allows Web services to be composed as the context changes. 相似文献