A hybrid distributed virtual environment （DVE） architecture is presented by importing a peer-to-peer （P2P） idea into the traditional client/server （C/S） architecture to improve the DVE system＇s scalability. The...A hybrid distributed virtual environment （DVE） architecture is presented by importing a peer-to-peer （P2P） idea into the traditional client/server （C/S） architecture to improve the DVE system＇s scalability. The mathematical model of the overload of the center server was built and a series of simulation experiments were performed to validate the conclusions. When the client number increases to a certain value, the hybrid architecture can reduce server overload with some special clients （temp servers） selected with a certain heuristic strategy. With this architecture, the DVE system can support more system clients with the same server hardware than the C/S architecture can. The server overload ＂pulse＂ phenomena causing by the exiting of the temp server can be resolved by adopting a more optimized temp server selecting strategy and by reducing the child client capability of the temp server. By combining the advantages of the C/S architecture and the P2P architecture, the hybrid DVE architecture can effectively improve the scalability of the DVE system. This is validated by theoretical analysis and simulation experiments.展开更多
In this article,the progress of marine geographic information system(MGIS) in China during 2006?2010 is reviewed with emphases on generic MGIS,advanced MGIS and MGIS-based applications.Generic MGIS can be divided into...In this article,the progress of marine geographic information system(MGIS) in China during 2006?2010 is reviewed with emphases on generic MGIS,advanced MGIS and MGIS-based applications.Generic MGIS can be divided into two categories:data-oriented MGIS and user-oriented MGIS,recent achievements of which by Chinese researchers are summarized respectively.Advanced MGIS mainly involves the establishment of 3D virtual marine environment and 'Digital Ocean'.An overview of the 3D MGIS based simulations in the context of ocean phenomena,ocean engineering and ocean battlefield is also presented.Several sug-gestions for future development of MGIS in China are proposed,and trends of development are addressed.展开更多
This paper studies the multiuser diversity with constellation selection based on a virtual representation of realistic Multiple Input Multiple Output （MIMO） correlated channels. To realize multiuser diversity in slo...This paper studies the multiuser diversity with constellation selection based on a virtual representation of realistic Multiple Input Multiple Output （MIMO） correlated channels. To realize multiuser diversity in slow fading channels, random beamforming is adopted. Random beamforming matrix exploiting virtual channel representation is constructed, which can match the channel matrix of the desired user better. Sirnultaneously, adaptive coded modulation is applied to each sub-channel of the selected user to improve the system performance further.展开更多
Remote data monitoring system which adopts virtual instrument usually applies data sharing, acquisition and remote transmission technology via internet. It is able to finish concurrent data acquisition and processing ...Remote data monitoring system which adopts virtual instrument usually applies data sharing, acquisition and remote transmission technology via internet. It is able to finish concurrent data acquisition and processing for multi-user and multi-task and also build a personalized virtual testing environment for more people but with fewer instruments. In this paper, we＇ 11 elaborate on the design and implementation of information sharing platform through a typical example of how to build multi-user concurrent virtual testing environment based on the virtnal software LabVIEW.展开更多
This paper puts forward sharing teaching resources based on cloud computing solutions, through the use of architecture means virtualization technology based on KVM on the server side, the infrastructure layer manage t...This paper puts forward sharing teaching resources based on cloud computing solutions, through the use of architecture means virtualization technology based on KVM on the server side, the infrastructure layer manage the underlying physical hardware equipment. In the realization of the infrastructure layer using Libvirt virtualization management suite that provides a common API development Web, through the RDP protocol, and finally access to the remote virtual desktop browser by the graphical user interface （GUI） and traditional Web B/S architecture, to simulate and access to low-level resources and sharing of teaching resources, teaching resources can be achieved education informatization in the process of teaching.展开更多
文摘A hybrid distributed virtual environment （DVE） architecture is presented by importing a peer-to-peer （P2P） idea into the traditional client/server （C/S） architecture to improve the DVE system＇s scalability. The mathematical model of the overload of the center server was built and a series of simulation experiments were performed to validate the conclusions. When the client number increases to a certain value, the hybrid architecture can reduce server overload with some special clients （temp servers） selected with a certain heuristic strategy. With this architecture, the DVE system can support more system clients with the same server hardware than the C/S architecture can. The server overload ＂pulse＂ phenomena causing by the exiting of the temp server can be resolved by adopting a more optimized temp server selecting strategy and by reducing the child client capability of the temp server. By combining the advantages of the C/S architecture and the P2P architecture, the hybrid DVE architecture can effectively improve the scalability of the DVE system. This is validated by theoretical analysis and simulation experiments.
基金supported by the Natural Science Foundation of China under projects 40730530 and 41076115the National Basic Research Program of China under project 2009CB723903the National High-Tech Research and Development Program of China under project 2008AA121701
文摘In this article,the progress of marine geographic information system(MGIS) in China during 2006?2010 is reviewed with emphases on generic MGIS,advanced MGIS and MGIS-based applications.Generic MGIS can be divided into two categories:data-oriented MGIS and user-oriented MGIS,recent achievements of which by Chinese researchers are summarized respectively.Advanced MGIS mainly involves the establishment of 3D virtual marine environment and 'Digital Ocean'.An overview of the 3D MGIS based simulations in the context of ocean phenomena,ocean engineering and ocean battlefield is also presented.Several sug-gestions for future development of MGIS in China are proposed,and trends of development are addressed.
基金Supported by the National Natural Science Foundation of China(No.60496311).
文摘This paper studies the multiuser diversity with constellation selection based on a virtual representation of realistic Multiple Input Multiple Output （MIMO） correlated channels. To realize multiuser diversity in slow fading channels, random beamforming is adopted. Random beamforming matrix exploiting virtual channel representation is constructed, which can match the channel matrix of the desired user better. Sirnultaneously, adaptive coded modulation is applied to each sub-channel of the selected user to improve the system performance further.
文摘Remote data monitoring system which adopts virtual instrument usually applies data sharing, acquisition and remote transmission technology via internet. It is able to finish concurrent data acquisition and processing for multi-user and multi-task and also build a personalized virtual testing environment for more people but with fewer instruments. In this paper, we＇ 11 elaborate on the design and implementation of information sharing platform through a typical example of how to build multi-user concurrent virtual testing environment based on the virtnal software LabVIEW.
文摘This paper puts forward sharing teaching resources based on cloud computing solutions, through the use of architecture means virtualization technology based on KVM on the server side, the infrastructure layer manage the underlying physical hardware equipment. In the realization of the infrastructure layer using Libvirt virtualization management suite that provides a common API development Web, through the RDP protocol, and finally access to the remote virtual desktop browser by the graphical user interface （GUI） and traditional Web B/S architecture, to simulate and access to low-level resources and sharing of teaching resources, teaching resources can be achieved education informatization in the process of teaching.
