The Experts below are selected from a list of 418206 Experts worldwide ranked by ideXlab platform

Mengchu Zhou - One of the best experts on this subject based on the ideXlab platform.

  • constraint aware approach to web service Composition
    Systems Man and Cybernetics, 2014
    Co-Authors: Pengwei Wang, Changjun Jiang, Zhijun Ding, Mengchu Zhou
    Abstract:

    The creation of value-added services by automatic Composition of existing ones is gaining significant momentum as the potential silver bullet in service-oriented computing. A large number of Composition Methods have been proposed, and most of them are based on the matching of input and output parameters of services only. However, most services in the real world are not universally applicable, and some applicable conditions or restrictions are imposed on them by their providers. Such constraints have a great impact on service Composition, but have been largely ignored by the existing Methods. In this paper, they are discussed and defined, and a simple formal expression is adopted to describe them. Two novel concepts, called service intension and service extension, are presented, which allow one to divide the basic elements of a web service definition into two parts. Consequently, their use allows us to propose a constraint-aware service Composition Method in which service constraints are well taken care. The proposed solution includes a graph search-based algorithm and two novel preprocessing Methods. A publicly available test set from ICEBE05 is used to evaluate and analyze the proposed Methodology.

  • automatic web service Composition based on horn clauses and petri nets
    Expert Systems With Applications, 2011
    Co-Authors: Xianfei Tang, Changjun Jiang, Mengchu Zhou
    Abstract:

    This paper introduces an automatic Web service Composition Method based on logical inference of Horn clauses and Petri nets. The Web service Composition problem is transformed into the logical inference problem of Horn clauses by exploring the dependency relations among services. An algorithm is presented, to determine whether the composite service exists in time that is linear in the size of the knowledge base. It can also return the rule set necessary for the Composition. Petri nets are chosen to model the rule set and its structural analysis techniques are used to obtain the composite service.

Chiawen Lin - One of the best experts on this subject based on the ideXlab platform.

  • motion vector refinement for high performance transcoding
    IEEE Transactions on Multimedia, 1999
    Co-Authors: Jeongnam Youn, Mingting Sun, Chiawen Lin
    Abstract:

    In transcoding, simply reusing the motion vectors extracted from an incoming video bit stream may not result in the best quality. In this paper, we show that the incoming motion vectors become nonoptimal due to the reconstruction errors. To achieve the best video quality possible, a new motion estimation should be performed in the transcoder. We propose a fast-search adaptive motion vector refinement scheme that is capable of providing video quality comparable to that can be achieved by performing a new full-scale motion estimation but with much less computation. We discuss the case when some incoming frames are dropped for frame-rate conversions, and propose motion vector Composition Method to compose a motion vector from the incoming motion vectors. The composed motion vector can also be refined using the proposed motion vector refinement scheme to achieve better results.

  • Motion vector refinement for high-performance transcoding
    Institute of Electrical and Electronics Engineers Inc., 1999
    Co-Authors: Jeongnam Youn, Mingting Sun, Chiawen Lin
    Abstract:

    [[abstract]]©1999 Institute of Electrical and Electronics Engineers-In transcoding, simply reusing the motion vectors extracted from an incoming video bit stream may not result in the best quality. In this paper, we show that the incoming motion vectors become nonoptimal due to the reconstruction errors. To achieve the best video quality possible, a new motion estimation should be performed in the transcoder. We propose a fast-search adaptive motion vector refinement scheme that is capable of providing video quality comparable to that can be achieved by performing a new full-scale motion estimation but with much less computation. We discuss the case when some incoming frames are dropped for frame-rate conversions, and propose motion vector Composition Method to compose a motion vector from the incoming motion vectors. The composed motion vector can also be refined using the proposed motion vector refinement scheme to achieve better results[[fileno]]2030144010005[[department]]電機工程學

Jeongnam Youn - One of the best experts on this subject based on the ideXlab platform.

  • motion vector refinement for high performance transcoding
    IEEE Transactions on Multimedia, 1999
    Co-Authors: Jeongnam Youn, Mingting Sun, Chiawen Lin
    Abstract:

    In transcoding, simply reusing the motion vectors extracted from an incoming video bit stream may not result in the best quality. In this paper, we show that the incoming motion vectors become nonoptimal due to the reconstruction errors. To achieve the best video quality possible, a new motion estimation should be performed in the transcoder. We propose a fast-search adaptive motion vector refinement scheme that is capable of providing video quality comparable to that can be achieved by performing a new full-scale motion estimation but with much less computation. We discuss the case when some incoming frames are dropped for frame-rate conversions, and propose motion vector Composition Method to compose a motion vector from the incoming motion vectors. The composed motion vector can also be refined using the proposed motion vector refinement scheme to achieve better results.

  • Motion vector refinement for high-performance transcoding
    Institute of Electrical and Electronics Engineers Inc., 1999
    Co-Authors: Jeongnam Youn, Mingting Sun, Chiawen Lin
    Abstract:

    [[abstract]]©1999 Institute of Electrical and Electronics Engineers-In transcoding, simply reusing the motion vectors extracted from an incoming video bit stream may not result in the best quality. In this paper, we show that the incoming motion vectors become nonoptimal due to the reconstruction errors. To achieve the best video quality possible, a new motion estimation should be performed in the transcoder. We propose a fast-search adaptive motion vector refinement scheme that is capable of providing video quality comparable to that can be achieved by performing a new full-scale motion estimation but with much less computation. We discuss the case when some incoming frames are dropped for frame-rate conversions, and propose motion vector Composition Method to compose a motion vector from the incoming motion vectors. The composed motion vector can also be refined using the proposed motion vector refinement scheme to achieve better results[[fileno]]2030144010005[[department]]電機工程學

Ahmed Karmouch - One of the best experts on this subject based on the ideXlab platform.

  • qos based Composition of service specific overlay networks
    IEEE Transactions on Computers, 2015
    Co-Authors: Yousif Al Ridhawi, Ahmed Karmouch
    Abstract:

    Optimization of service Compositions represents a challenging area of research in mobile networks. The use of formal semantic descriptions of service interfaces and functionalities enable automated reasoning over service Compositions. The growing challenge of finding effective Methods to satisfy non-functional QoS requirements of customers exacerbates the Composition problem. Fuzzy reasoning provides an effective means to represent QoS concepts that are vague or approximate thus providing a flexible best-match service query scheme. This paper presents a new fuzzy-induced, semantic-similarity-based service-specific overlay network Composition over a hybrid service overlay network. The presented Composition Method allows for efficient, accurate, and QoS-aware component service discovery, Composition, and execution. We demonstrate that our approach provides better performance and reduced Composition delay when compared to other service-Composition solutions.

  • Decentralized Plan-Free Semantic-Based Service Composition in Mobile Networks
    IEEE Transactions on Services Computing, 2015
    Co-Authors: Yousif Al Ridhawi, Ahmed Karmouch
    Abstract:

    The inefficiency of one-to-one matching of user requirements to a single service has given rise to service Composition. Service Composition allows simple services to be dynamically combined into more complex services. In mobile environments, service discovery and integration involves cooperation between various service nodes where reliance on a centralized service registry introduces efficiency and single point of failure problems. Plan- and workflow-based Composition solutions restrict service discovery to defined abstract models. Semantic similarity measurements play an important role in service integration. In this paper we introduce a semantic similarity and semantic nearness service Composition Method. The objective of our work is to free service nodes from adherence to restrictive Composition plans. Our work also enables Compositions to succeed in dynamic environments through a decentralized solution even when nodes are unaware of nearby service nodes. This paper presents a service Composition solution that semantically advances Composition paths towards users' needs with each service hop while guaranteeing a user-acceptable QoS level. Simulation results showcase the effectiveness of the presented solution and its compatibility with underlying service discovery Methods.

  • an adaptive vertical handover in service specific overlay networks
    Symposium on Applications and the Internet, 2012
    Co-Authors: Yousif Al Ridhawi, Ismaeel Al Ridhawi, Nancy Samaan, Ahmed Karmouch
    Abstract:

    This paper proposes a new vertical handover (VHO)-enhanced mobile service discovery and Composition Method over a hybrid service overlay network (H-SON). The overlay considers the dynamic characteristics of mobile nodes in the decision for node placement as well as the types of services provided and Quality of Service (QoS) levels. The mobile nature of media clients provokes a necessity to consider VHO operations to meet the requirements of offered service level agreements (SLAs). The integrated framework continuously derives optimal VHO configuration policies with respect to handover initiation and network selection for service specific overlay network (SSON) node migration. The VHO-enhanced service Composition Method allows for efficient, accurate, and QoS-aware component service discovery, Composition, and execution. We demonstrate that our approach provides better performance and reduced Composition delay in heterogeneous network environments when compared to other service-Composition solutions.

Jinjun Chen - One of the best experts on this subject based on the ideXlab platform.

  • A QoS-aware Composition Method supporting cross-platform service invocation in cloud environment
    Journal of Computer and System Sciences, 2012
    Co-Authors: Wanchun Dou, Xuyun Zhang, Jinjun Chen
    Abstract:

    With the increasing popularity of cloud computing technologies, more and more service Composition processes are enacted and executed in could environment. Compared with the various and approximately infinite application requirements from end users, the web services held by a cloud platform are usually limited. Therefore, it is often a challenging effort to develop a service Composition, in such a situation that only part of the functional qualified candidate services could be found inside a cloud platform. In this situation, the absent services will be invocated in a cross-platform way outside the cloud platform. In view of this challenge, a QoS-aware Composition Method is investigated for supporting cross-platform service invocation in cloud environment. Furthermore, some experiments are deployed to evaluate the Method presented in this paper.

  • combining local optimization and enumeration for qos aware web service Composition
    International Conference on Web Services, 2010
    Co-Authors: Lianyong Qi, Ying Tang, Jinjun Chen
    Abstract:

    Web service Composition, i.e., WSC, has emerged as a promising way to integrate various distributed computing resources for complex application requirements. However, much computation time is needed to determine the optimal composite solution, which embarrasses the popularity of WSC in actual real time applications. In view of this challenge, in this paper, a heuristic service Composition Method, named LOEM (Local Optimization and Enumeration Method, LOEM), is proposed. It aims at filtering the candidates of each task to a small number of promising ones by local selection, and then enumerates all the composite solutions to pursue a near-to-optimal one. The experiment results demonstrate the feasibility of LOEM in dealing with the WSC problems.