Key Technologies Research Of Shipping Information Service Grid

Shipping information service platform is one of main sign of modern shipping service mode, based on the network information technology. It takes shipping information interaction, sharing and system integration as goal, stresses on achieving dynamic information exchange for ship, cargo and sea-route etc, and finally build an information service platform facing to management, organization and service. The architecture of shipping information service platform must consider the effective utilization of existing system and resource, need to integrate heteroid systems for different periods, type and fields, eliminate isolated information resources and achieve cooperation, interaction and sharing among systems, react rapidly to dynamic business requirements, improve system expansibility and openness and make loose coupling system, etc. Grid provides the effective approach to research and resolve the issues above. Grid integrates high-speed Internet, high performance computers, large database, sensors, remote equipments and other shipping resources and achieves the sharing and interoperability within the system. Service Grid, combining Web Service architecture and Grid, proposes the concept of "Grid Service" and apply to service discovery, dynamic service creation and service life-cycle management etc. which are related to temporary services. This ensures the Service Grid to respond to and handle various kinds of requirements for shipping information, provide a safe and effective sharing mechanism for shipping resources, make various heteroid and isolate resources work cooperatively, in order to provide service to different applications as a whole and achieving resource sharing and integration among organizations.The emphasis of this paper is to discuss how to apply Service Grid in shipping information system, and establish flexible, effective, reliable and extendible shipping information service platform. Based on this Shipping Information Service Grid architecture, the paper analyzes and researches the key technologies including task scheduling and resource allocation of Service Grid and provides new direction and solid foundation for further research of applying Service Grid in shipping information system.Firstly, the paper analyzes characters of current shipping information system such as mass data and missing information sharing and cooperation among heteroid system, etc, investigates current Service Grid and propose to build Shipping Information Service Grid architecture based on OGSA and WSRF. This architecture integrates service model into Grid and make nodes in Grid based on service, so that applications are divided into more granular module and improve loose-couple capability among Grid nodes. Since modules on each node are based on service, it is easy to establish communication among nodes and cooperators and achieves flexible, distributed and unrestricted communicated architecture. This architecture completely considers service discovery, strategy, security, resource management and scheduling mechanism of Grid, to ensure Grid users discover required services quickly, cooperate with other users within Grid, optimize services according to his authority and utilize the best matched service to satisfy the user's requirement. This resolves the sharing and cooperation issues among heteroid systems in shipping system. Also the paper investigates deeply on how to integrate Grid Service layer with shipping information system in this architecture and to describe whole process of how shipping system to provide services in this architecture according to one of cases.Secondly, the paper analyses goal of task scheduling of Service Grid, investigates and compares existing task scheduling algorithms. Based on this, the paper considers Shipping Information Service Grid to need to support QoS of complex and multiple objectives and the character of tasks related, then to propose a integrated utility of multiple QoS attributions scheduling algorithm based on correlative tasks, referring to Buyya's scheduling strategy and computing economic scheduling. This algorithm describes multiple QoS attributions of users as utility function. Since it cannot satisfy multiple QoS attributes at the same time, even some services objectives have conflicts, the paper trades off among multiple utility functions and get an integrated general utility function, take this general utility function as optimized objective function for task scheduling to drive dynamic resource scheduling, finally find the task scheduling with maximum utility. This paper utilizes GridSim to simulate the algorithm, compares with classic DBC-T algorithm, DBC-C algorithm and DBC-CT algorithm. The result shows that this algorithm can balance multiple QoS attributes but not only a single optimized objective. This can reflect best requirements of users and has higher execution performance, comparing with current task scheduling. Finally, the paper investigates the resource allocation of Shipping Information Service Grid. This paper takes further research for resource allocation of Service Grid by utilizing game theory and microeconomic method. Based on the research of existing Service Grid resource allocation methods, according to the dynamic character of information of Shipping Information Service Grid and the correlative dependent and compete each other characters of different service requests for the resource occupation and utilization, the paper designs a bi-modes resource allocation model. This model applies compete price mechanism, when there are plenty of Grid resources, it applies proportional sharing mechanism pattern based on sequential game, make optimalizing resource allocation based on Nash equilibrium and provide optimal selling price for resource provider; when Grid resources are absent, it allocate resources by utilizing compete price pattern and based on the maximum utility function, which ensure Service Grid resources are allocated among multiple service requests. The paper also takes further discussion about some key points of this model such as maximumly utilizing Grid resources. This provides a good solution for how to effective resource allocation and a solid foundation for further research.The paper provides a new thought and a new direction of research of shipping information system, which is to introduce Service Grid and build a Shipping Information Service Grid. Integrating Service Grid and some other intelligent methods, this model can resolve key issues in shipping information system, such as handling complex mass data, heteriod system and information sharing, etc. But since the limited time and energy, this paper only did preliminary research on integration of shipping information system and Service Grid, it mainly focuses on research on Shipping Information Service Grid architecture, task scheduling and resource allocation. There are still more detail works need to be further researched and discussed in the future that are indicated in the last of paper.Please point them out if there are deficiencies in this paper.