Nebulas Data Exchange Interface Technology And Achieved

With the development of scientific research and technology, more and more scientific research institutions aware of the sharing of their data, to provide their existing services can be greater promotion of scientific research process, but such a heterogeneous distributed service invocation and data acquisition is a challenge to scientists. Scientific workflow management system can shield the bottom of the computer implementation details and through a graphical user interface to calls service on heterogeneous systems and data investigation process style.Nebulas is a lightweight scientific workflow management system, which by Computer Technology Application Key Laboratory independent research and development and is mainly used in astronomy field. Scientific workflow system in the astronomical field in china has not been widely used. If there a stable and reliable scientific workflow system to help solve the facing data access and data processing problems, it will greatly enhance the astronomy work efficiency. The Nebulas system's ultimate goal is to design and implementation of a field in astronomy for astronomers using the scientific workflow system.The Nebulas data transfer is more complex part of the system. This thesis research and design the Nebulas for data exchange interface technology, to complete the transfer of data in the system. This study included the following aspects:First, this thesis research, design and realization of a data definition, the definition of the data includes metadata information and data information:metadata description of the object in the format of the data encoding, and semantic markup information; data information include the scientific data. Nebulas need a data definition to receive and description of the data in the process defined. Through the data definition, Nebulas can manage the data definition.Second, in order to call the network-based heterogeneous resources, Nebulas designs and implements the processors packaging these resources. This paper implements processor's port structure. First of all, the data definition in the implementation can be effective incoming and outgoing of the processors; and followed by port structure identification and management well defined data analysis process, and scientists can share and repeated calls to them. Nebulas the call package of resources to the corresponding processor, processor requires a valid receive data, return data to complete the calculation, and the execution unit can effectively identify and manage through this feature, scientists have defined validation the implementation process can be repeated use and share among scientists.Third, Nebulas package service call into a form of processor, and it needs to pass data between the processors. This thesis designed and realized the connection and control structure between the processor. Through the structure, Nebulas can implements data type matching between the processors and service performed in parallel. Data analysis of scientific experiments, they may need call multiple services on a network to perform a continuous process. In Nebulas it needs to define a data execution process, through the connection and control structure, the different processors of the experimental process data is defined in the implementation process the transfer of data through the execution definition.Technological achievements discuss above has been used in Nebulas. By the results of this thesis, the Nebulas you can achieve data transfer of data in the calculation process in system execution. The data exchange interface technology in this paper can not only used in Nebulas, the research results can provide a solution for other scientific workflow management system or system call heterogeneous resources of data transfer interface.