Key Technologies For Smart City Information System

As human gathering centers and trade centers, cities are the signs of human civilization progress. Urbanization is an inevitable trend of urban development, The way towards urbanization is coupled with a string of social problems, which is exemplified by the low efficiency of urban management model, crowded traffic system, emergency system without actual effect, and incomplete environmental monitoring system, etc. Digital cities collect, analyse and deal with urban management problems based on various technical means such as GPS, GIS, RS, computers, network communication and so on. Significant results are obtained by implement of grid management and urban component management in urban order, traffic, sanitation and planning. Smart cities’information systems must have enhanced computing power, sensory ability and data application. The development of cloud computing, internet of things and semantic net is the matter of feasibility to the construction of smart cities. The research of cloud computing, Internet of Things and the Semantic Web application infrastructure and key technology has important theoretical significance and practical value.This article had a depth studied on three key technologies including cloud computing resource schedule of urban data center, framework of urban sensor network and designs of middlewares, and organization and application of urban linked date, which are on the basis of demands, planning, implementation and operation of Wuhan Smart City and its major project municipal administrative service center. On the basis of analyzing smart city information system demand. Firstly, it establishes scheduling mode of cloud computing virtual resource based upon evolutionary algorithm. Secondly, it presents repertoire and implementation method of urban sensor networks. Finally, it states organization and application of government Linked data on face of a mass of sensor data. Researched theory and key technology will, on the one hand, possess import theory significance on planning, designs, implementation and evaluation of smart city information system, and, on the other, have important practical value on improving urban public service and maintaining urban sustainable development in the future.This article possesses the following contribution and innovation on key technologies and application proposals: (1) Allocation method of cloud computing virtual machines on the base of multiple-objective evolutionary algorithmAccording to the data center cloud computing resources scheduling model, strategy and goal, the article puts forward the first distribution of virtual machine resources and self-adaptive dynamic scheduling method, meanwhile, because of virtual machines with characteristics of multidimensional vector, it proposes allocation algorithm of resource virtual machines based on multi-objective evolutionary algorithm and it comes out comprehensive load capacity evaluation strategy based on performance vector, trigger migration strategy based on the historical load data, positioning strategy implementation based on migration traffic, and selection strategy of migration physical target machines based on the optimum matching. Therefore, with respect to the maintaining of application service, virtual machine migration frequency can be more effectively reduced, as well as the migration’s influence on overall performance of the cloud computing center, at the same time, fewer physical servers are equipped, the server resources can be used effectively, and energy saving achieves better effect.(2) To urban sensor network repertoire and frame works of middlewares under ubiquitous serviceSmart city converges isomerism, multiple dimensions and time phase, and a great deal of ubiquitous information, so a unified data access and collection mechanism needs to build. Based on the calculation framework of internet of things, the article puts forward the data acquisition and transmission of urban sensor network, and the repertoire of calculation service. In view of the functional requirements of the internet of things’gateway, the construction method of software system and hardware system is proposed, and the article also presents the middleware structure of urban sensor network as required by M2M, namely, the structure can not only realize dynamic management of sensor resources, but also support ubiquitous service through HTTP protocol. This has important significance in providing intelligent service by solver, controller and computing terminal under diversity conditions.(3) The organization and application method of Linked government dataLinked semantic data are widely used in semantic search and personalized recommend intelligent service. Resources released by Linked data technology with the characteristics of share, reusability, structurization and normalized are in favor of integrating isolated government data. The article presents a technology automatically generating high quality Linked data through jointly infering attribute items, table element values and the relationship between attribute items. This technology builds links among the same and different fields of government resources, and realize the query across both platform and system. It possess great theoretical significance to network knowledge management and knowledge serving science problem solving and the network resource semantic level Internet sharing has prospect widely application.To sum up, this article studies how to enhancing smart city operational capability, sensory ability and data application capability in the following three steps.The first step is to present allocation method of cloud computing virtual machines on the base of multiple-objective evolutionary algorithm. The second step is to establish urban sensor networks and frame works of middlewares. The last step is to research on generation technology and application of Linked government data. Finally, all the above research results are fed into projects of Wuhan smart city and urban administrative service center and they turn out to be valuable both in theoretical model and technical proposal.