The goal of web service composition is to choose an optimal scheme according to Quantity of Service （QoS） which selects instances in a distributed network. The networks are clustered with some web services such as o...The goal of web service composition is to choose an optimal scheme according to Quantity of Service （QoS） which selects instances in a distributed network. The networks are clustered with some web services such as ontologies, algorithms and rule engines with similar function and interfaces. In this scheme, web services acted as candidate service construct a distributed model which can＇t obtain the global services＇ information. The model is utilized to choose instances according to local QoS information in the progress of service composition. Some QoS matrixes are used to record and compare the instance paths and then choose a better one. Simulation result has proven that our ~pproach has a tradeoff between efficiency and ~quality.展开更多
E-commerce systems for construction material procurement are becoming increasingly important in Hong Kong. These E-commerce systems are non-interoperable and create problems for the buyers who use these systems to pur...E-commerce systems for construction material procurement are becoming increasingly important in Hong Kong. These E-commerce systems are non-interoperable and create problems for the buyers who use these systems to purchase construction materials. This paper presents the mobile agent-based approach and Web services-based approach for enabling interoperation of these systems in the E-Union environment.展开更多
This paper proposes a policy driven and multi-agent based model to enhance the fault tolerance and recovery capabilities of Web services in distributed environment. The evaluation function of fault specifications and ...This paper proposes a policy driven and multi-agent based model to enhance the fault tolerance and recovery capabilities of Web services in distributed environment. The evaluation function of fault specifications and the corresponding handling mechanisms of the services are both defined in policies, which are expressed in XML. During the implementation of the services,the occurrences of faults are monitored by the service monitor agent through the local knowledge on the faults. Such local knowledge is dynamically generated by the service policy agent through querying and parsing the service policies from the service policies repository. When the fault occurs, the service process agent will focus on the process of fault handling and service recovery, which will be directed with the actions defined in the policies upon the specific conditions. Such a policy driven and multi-agent based fault handling approach can address the issues of flexibility, automation and availability.展开更多
Recent emergence of diverse services have led to explosive traffic growth in cellular data networks. Understanding the service dynamics in large cellular networks is important for network design, trouble shooting, qua...Recent emergence of diverse services have led to explosive traffic growth in cellular data networks. Understanding the service dynamics in large cellular networks is important for network design, trouble shooting, quality of service(Qo E) support, and resource allocation. In this paper, we present our study to reveal the distributions and temporal patterns of different services in cellular data network from two different perspectives, namely service request times and service duration. Our study is based on big traffic data, which is parsed to readable records by our Hadoop-based packet parsing platform, captured over a week-long period from a tier-1 mobile operator's network in China. We propose a Zipf's ranked model to characterize the distributions of traffic volume, packet, request times and duration of cellular services. Two-stage method(Self-Organizing Map combined with kmeans) is first used to cluster time series of service into four request patterns and three duration patterns. These seven patterns are combined together to better understand the fine-grained temporal patterns of service in cellular network. Results of our distribution models and temporal patterns present cellular network operators with a better understanding of the request and duration characteristics of service, which of great importance in network design, service generation and resource allocation.展开更多
Rapid developments in network systems of business service have resulted in more reliance on distributed computing, typified by “subscriber/push” architectures. Unfortunately, frequent and unexpectable network failur...Rapid developments in network systems of business service have resulted in more reliance on distributed computing, typified by “subscriber/push” architectures. Unfortunately, frequent and unexpectable network failures were routine, and downtime was not in hours, but in days. High availability has become the most important factor decreasing business risk and improving Quality of Service. Cluster technology has solved the non-stop problem on Local Area Network. However, most technologies including cluster today fail to ensure the non-stop Internet service based on Routers. With good performance on high availability and fault tolerance, quorum systems are very suitable for application to distributed business service networks. In this work, we modeled and developed a non-stop Internet service system based on a new quorum system, circle quorum system, for Boston Mutual Fund Broker, US. With five protocols, it provided highly available data services for clients on Internet.展开更多
基金National Natural Science Foundation of China，Major National Science and Technology Projects of New Generation Broadband Wireless Mobile Communication Network，the National High Technology Research and Development Program of China (863 Program)
文摘The goal of web service composition is to choose an optimal scheme according to Quantity of Service （QoS） which selects instances in a distributed network. The networks are clustered with some web services such as ontologies, algorithms and rule engines with similar function and interfaces. In this scheme, web services acted as candidate service construct a distributed model which can＇t obtain the global services＇ information. The model is utilized to choose instances according to local QoS information in the progress of service composition. Some QoS matrixes are used to record and compare the instance paths and then choose a better one. Simulation result has proven that our ~pproach has a tradeoff between efficiency and ~quality.
文摘E-commerce systems for construction material procurement are becoming increasingly important in Hong Kong. These E-commerce systems are non-interoperable and create problems for the buyers who use these systems to purchase construction materials. This paper presents the mobile agent-based approach and Web services-based approach for enabling interoperation of these systems in the E-Union environment.
文摘This paper proposes a policy driven and multi-agent based model to enhance the fault tolerance and recovery capabilities of Web services in distributed environment. The evaluation function of fault specifications and the corresponding handling mechanisms of the services are both defined in policies, which are expressed in XML. During the implementation of the services,the occurrences of faults are monitored by the service monitor agent through the local knowledge on the faults. Such local knowledge is dynamically generated by the service policy agent through querying and parsing the service policies from the service policies repository. When the fault occurs, the service process agent will focus on the process of fault handling and service recovery, which will be directed with the actions defined in the policies upon the specific conditions. Such a policy driven and multi-agent based fault handling approach can address the issues of flexibility, automation and availability.
基金supported by the National Basic Research Program of China (973 Program: 2013CB329004)
文摘Recent emergence of diverse services have led to explosive traffic growth in cellular data networks. Understanding the service dynamics in large cellular networks is important for network design, trouble shooting, quality of service(Qo E) support, and resource allocation. In this paper, we present our study to reveal the distributions and temporal patterns of different services in cellular data network from two different perspectives, namely service request times and service duration. Our study is based on big traffic data, which is parsed to readable records by our Hadoop-based packet parsing platform, captured over a week-long period from a tier-1 mobile operator's network in China. We propose a Zipf's ranked model to characterize the distributions of traffic volume, packet, request times and duration of cellular services. Two-stage method(Self-Organizing Map combined with kmeans) is first used to cluster time series of service into four request patterns and three duration patterns. These seven patterns are combined together to better understand the fine-grained temporal patterns of service in cellular network. Results of our distribution models and temporal patterns present cellular network operators with a better understanding of the request and duration characteristics of service, which of great importance in network design, service generation and resource allocation.
文摘Rapid developments in network systems of business service have resulted in more reliance on distributed computing, typified by “subscriber/push” architectures. Unfortunately, frequent and unexpectable network failures were routine, and downtime was not in hours, but in days. High availability has become the most important factor decreasing business risk and improving Quality of Service. Cluster technology has solved the non-stop problem on Local Area Network. However, most technologies including cluster today fail to ensure the non-stop Internet service based on Routers. With good performance on high availability and fault tolerance, quorum systems are very suitable for application to distributed business service networks. In this work, we modeled and developed a non-stop Internet service system based on a new quorum system, circle quorum system, for Boston Mutual Fund Broker, US. With five protocols, it provided highly available data services for clients on Internet.
