The Experts below are selected from a list of 45 Experts worldwide ranked by ideXlab platform

Bettina Schnor - One of the best experts on this subject based on the ideXlab platform.

  • Service replication in grids ensuring consistency in a dynamic failure prone environment
    International Parallel and Distributed Processing Symposium, 2008
    Co-Authors: Andre Luckow, Bettina Schnor
    Abstract:

    A major challenge in a Service-oriented environment as a Grid is fault tolerance. The more resources and Services involved, the more complicated and error-prone becomes the system. Migol (Luckow and Schnor, 2008) is a Grid middleware, which addresses the fault tolerance of Grid applications and Services. Migol's core component is its Registry Service called application information Service (AIS). To achieve fault tolerance and high availability the AIS is replicated on different sites. Since a Registry is a stateful Web Service, the replication of the AIS is no trivial task. In this paper, we present our concept for active replication of Grid Services. Migol's Replication Service uses a token-based algorithm and certificate-based security to provide secure group communication. Further, we show in different experiments that active replication in a real Grid environment is feasible.

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

  • A Semantic Registry Method Using Sensor Metadata Ontology to Manage Heterogeneous Sensor Information in the Geospatial Sensor Web
    ISPRS International Journal of Geo-Information, 2016
    Co-Authors: Changjiang Xiao, Nengcheng Chen, Xiaolei Wang, Zeqiang Chen
    Abstract:

    Efficient information management and precise discovery of heterogeneous sensors in the Geospatial Sensor Web (GSW) are a major challenge. Intelligent sensor management requires a Registry Service to store and process sensor information efficiently. In this paper, we propose a Sensor Metadata Ontology (SMO) to achieve a unified semantic description for heterogeneous sensors that is used to express sensor semantics. Through mapping between the sensor Registry information model and the SMO, the sensor metadata could be stored with semantic information for the Registry. The framework of a Sensor Semantic Registry Service (SSRS) has been successfully implemented for the registration and discovery of heterogeneous sensors. The results of GEOSENSOR-SSRS experiments show that the proposed semantic Registry method can be used to enable sharing in an open distributed sensor network as well as to promote accuracy and efficiency of discovery.

  • a direct Registry Service method for sensors and algorithms based on the process model
    Computers & Geosciences, 2013
    Co-Authors: Nengcheng Chen, Xiaolei Wang, Xunliang Yang
    Abstract:

    To characterize and monitor environmental quality in real time, significant efforts must be made to make sensors accessible on the Web. Although a number of Services have shown great potential to improve the accuracy and reliability of sensor Registry, comprehensive methods that register sensors and algorithms in a catalogue Service based on a process model are lacking. This paper addresses the Registry of processes, including physical and non-physical processes, by using the OGC catalogue Service. To provide more information on sensors and algorithms, the process catalogue information model extends the ebXML Registry information Model. The mapping between the metadata encoded in SensorML and the extended model includes more information for all types of processes. Moreover, the mapping includes the relationship among processes and their categories based on the properties of sensors and algorithms. The effectiveness of the improved model is registered and implemented in GEOSENSOR CSW, following the OGC "transaction" interface. Flooding experimental results demonstrate that the Service can effectively and directly register sensors and algorithms so that processes can be flexibly executed according to users' demands. A Registry method for sensors and algorithms based on the Process Model was proposed.The ebXML Registry Information Model was extended to fully support the Process Model.SensorML to ebRIM mappings included all types of processes and the relationships.The GEOSENSOR CSW prototype application was designed and implemented.Flood experiment case studies demonstrated effectiveness of the proposed method.

Xiaolei Wang - One of the best experts on this subject based on the ideXlab platform.

  • A Semantic Registry Method Using Sensor Metadata Ontology to Manage Heterogeneous Sensor Information in the Geospatial Sensor Web
    ISPRS International Journal of Geo-Information, 2016
    Co-Authors: Changjiang Xiao, Nengcheng Chen, Xiaolei Wang, Zeqiang Chen
    Abstract:

    Efficient information management and precise discovery of heterogeneous sensors in the Geospatial Sensor Web (GSW) are a major challenge. Intelligent sensor management requires a Registry Service to store and process sensor information efficiently. In this paper, we propose a Sensor Metadata Ontology (SMO) to achieve a unified semantic description for heterogeneous sensors that is used to express sensor semantics. Through mapping between the sensor Registry information model and the SMO, the sensor metadata could be stored with semantic information for the Registry. The framework of a Sensor Semantic Registry Service (SSRS) has been successfully implemented for the registration and discovery of heterogeneous sensors. The results of GEOSENSOR-SSRS experiments show that the proposed semantic Registry method can be used to enable sharing in an open distributed sensor network as well as to promote accuracy and efficiency of discovery.

  • a direct Registry Service method for sensors and algorithms based on the process model
    Computers & Geosciences, 2013
    Co-Authors: Nengcheng Chen, Xiaolei Wang, Xunliang Yang
    Abstract:

    To characterize and monitor environmental quality in real time, significant efforts must be made to make sensors accessible on the Web. Although a number of Services have shown great potential to improve the accuracy and reliability of sensor Registry, comprehensive methods that register sensors and algorithms in a catalogue Service based on a process model are lacking. This paper addresses the Registry of processes, including physical and non-physical processes, by using the OGC catalogue Service. To provide more information on sensors and algorithms, the process catalogue information model extends the ebXML Registry information Model. The mapping between the metadata encoded in SensorML and the extended model includes more information for all types of processes. Moreover, the mapping includes the relationship among processes and their categories based on the properties of sensors and algorithms. The effectiveness of the improved model is registered and implemented in GEOSENSOR CSW, following the OGC "transaction" interface. Flooding experimental results demonstrate that the Service can effectively and directly register sensors and algorithms so that processes can be flexibly executed according to users' demands. A Registry method for sensors and algorithms based on the Process Model was proposed.The ebXML Registry Information Model was extended to fully support the Process Model.SensorML to ebRIM mappings included all types of processes and the relationships.The GEOSENSOR CSW prototype application was designed and implemented.Flood experiment case studies demonstrated effectiveness of the proposed method.

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

  • A Semantic Registry Method Using Sensor Metadata Ontology to Manage Heterogeneous Sensor Information in the Geospatial Sensor Web
    ISPRS International Journal of Geo-Information, 2016
    Co-Authors: Changjiang Xiao, Nengcheng Chen, Xiaolei Wang, Zeqiang Chen
    Abstract:

    Efficient information management and precise discovery of heterogeneous sensors in the Geospatial Sensor Web (GSW) are a major challenge. Intelligent sensor management requires a Registry Service to store and process sensor information efficiently. In this paper, we propose a Sensor Metadata Ontology (SMO) to achieve a unified semantic description for heterogeneous sensors that is used to express sensor semantics. Through mapping between the sensor Registry information model and the SMO, the sensor metadata could be stored with semantic information for the Registry. The framework of a Sensor Semantic Registry Service (SSRS) has been successfully implemented for the registration and discovery of heterogeneous sensors. The results of GEOSENSOR-SSRS experiments show that the proposed semantic Registry method can be used to enable sharing in an open distributed sensor network as well as to promote accuracy and efficiency of discovery.

Andre Luckow - One of the best experts on this subject based on the ideXlab platform.

  • Service replication in grids ensuring consistency in a dynamic failure prone environment
    International Parallel and Distributed Processing Symposium, 2008
    Co-Authors: Andre Luckow, Bettina Schnor
    Abstract:

    A major challenge in a Service-oriented environment as a Grid is fault tolerance. The more resources and Services involved, the more complicated and error-prone becomes the system. Migol (Luckow and Schnor, 2008) is a Grid middleware, which addresses the fault tolerance of Grid applications and Services. Migol's core component is its Registry Service called application information Service (AIS). To achieve fault tolerance and high availability the AIS is replicated on different sites. Since a Registry is a stateful Web Service, the replication of the AIS is no trivial task. In this paper, we present our concept for active replication of Grid Services. Migol's Replication Service uses a token-based algorithm and certificate-based security to provide secure group communication. Further, we show in different experiments that active replication in a real Grid environment is feasible.