A hierarchical clustered BitTorrent （CBT） system is proposed to improve the file sharing perior-mance of the BitTorrent system, in which peers are grouped into clusters in a large-scale BitTorrent-hke underlying ove...A hierarchical clustered BitTorrent （CBT） system is proposed to improve the file sharing perior-mance of the BitTorrent system, in which peers are grouped into clusters in a large-scale BitTorrent-hke underlying overlay network in such a way that clusters are evenly distributed and that the peers within the cluster are relatively close to each other. A fluid model is developed to compare the performance of the proposed CBT system with the BitTorrent system, and the result shows that the CBT system can effectively improve the performance of the system. Simulation results also demonstrate that the CBT system improves the system scalabihty and efficiency while retaining the robustness and incentives of the original BitTorrent paradigm.展开更多
This paper introduces the architecture and implementation of an industrial robot control system based on Windows NT. This robot control system, which is based on a single-processor structure, can run on general indust...This paper introduces the architecture and implementation of an industrial robot control system based on Windows NT. This robot control system, which is based on a single-processor structure, can run on general industrial computers. Owing to using Windows NT's real-time extension RTX, the control system can achieve good realtime performance and friendly user interface in one general-purpose operating system. A three layer hierarchical architecture of control software is proposed to make the system more scalable and flexible. Furthermore a communication and configuration system is implemented to enable modules to communicate with each other, which make the control system scalable and flexible.展开更多
Due to the substantial role of bridges in transportation networks and in accordance with the limited funding for bridge management, remediation strategies have to be prioritised. A conservative bridge assessment will ...Due to the substantial role of bridges in transportation networks and in accordance with the limited funding for bridge management, remediation strategies have to be prioritised. A conservative bridge assessment will result in unnecessary actions, such as costly bridge strengthening or repairs. On the other hand, any bridge maintenance negligence and delayed actions may lead to heavy future costs or degraded assets. The accuracy of decisions developed by any manager or bridge engineer relies on the accuracy of the bridge condition assessment which emanates from visual inspection. Many bridge rating systems are based on a very subjective procedure and are associated with uncertainty and personal bias. The developing condition rating method described herein is an important step in adding more holism and objectivity to the current approaches. Structural importance and material vulnerability are the two main factors that should be considered in the evaluation of element structural index and the causal factor as the representative of age, environment, road class and inspection is implemented as a coefficient to the OSCI （overall structural condition index）. The AHP （analytical hierarchy process） has been applied to evaluate the priority vector of the causal parameters.展开更多
The paper shows a proposition of metrics for measuring the complexity of the business organization and business software. The metrics is based on a subjective estimation of complexity of the elements from a part of th...The paper shows a proposition of metrics for measuring the complexity of the business organization and business software. The metrics is based on a subjective estimation of complexity of the elements from a part of the structure of business organization or business software in relation to other elements from the observed part. Estimation is performed based on the measuring scale for comparison of complexity of elements, and reaching a final conclusion on the complexity of elements in relation to other elements, through the Analytic Hierarchy Process （AHP）. Defined in this manner, the metrics represents a unique metrics for measuring the complexity of elements of business organization and business software, which enables their comparison. The paper also presents a short overview of existing metrics for measuring the complexity of business organization and business software.展开更多
基金the National High Technology Research and Development Programme of China(No2004AA104280,2006AA01Z172)
文摘A hierarchical clustered BitTorrent （CBT） system is proposed to improve the file sharing perior-mance of the BitTorrent system, in which peers are grouped into clusters in a large-scale BitTorrent-hke underlying overlay network in such a way that clusters are evenly distributed and that the peers within the cluster are relatively close to each other. A fluid model is developed to compare the performance of the proposed CBT system with the BitTorrent system, and the result shows that the CBT system can effectively improve the performance of the system. Simulation results also demonstrate that the CBT system improves the system scalabihty and efficiency while retaining the robustness and incentives of the original BitTorrent paradigm.
基金Supported by National Natural Science foundation of China (No. 69975014)
文摘This paper introduces the architecture and implementation of an industrial robot control system based on Windows NT. This robot control system, which is based on a single-processor structure, can run on general industrial computers. Owing to using Windows NT's real-time extension RTX, the control system can achieve good realtime performance and friendly user interface in one general-purpose operating system. A three layer hierarchical architecture of control software is proposed to make the system more scalable and flexible. Furthermore a communication and configuration system is implemented to enable modules to communicate with each other, which make the control system scalable and flexible.
文摘Due to the substantial role of bridges in transportation networks and in accordance with the limited funding for bridge management, remediation strategies have to be prioritised. A conservative bridge assessment will result in unnecessary actions, such as costly bridge strengthening or repairs. On the other hand, any bridge maintenance negligence and delayed actions may lead to heavy future costs or degraded assets. The accuracy of decisions developed by any manager or bridge engineer relies on the accuracy of the bridge condition assessment which emanates from visual inspection. Many bridge rating systems are based on a very subjective procedure and are associated with uncertainty and personal bias. The developing condition rating method described herein is an important step in adding more holism and objectivity to the current approaches. Structural importance and material vulnerability are the two main factors that should be considered in the evaluation of element structural index and the causal factor as the representative of age, environment, road class and inspection is implemented as a coefficient to the OSCI （overall structural condition index）. The AHP （analytical hierarchy process） has been applied to evaluate the priority vector of the causal parameters.
文摘The paper shows a proposition of metrics for measuring the complexity of the business organization and business software. The metrics is based on a subjective estimation of complexity of the elements from a part of the structure of business organization or business software in relation to other elements from the observed part. Estimation is performed based on the measuring scale for comparison of complexity of elements, and reaching a final conclusion on the complexity of elements in relation to other elements, through the Analytic Hierarchy Process （AHP）. Defined in this manner, the metrics represents a unique metrics for measuring the complexity of elements of business organization and business software, which enables their comparison. The paper also presents a short overview of existing metrics for measuring the complexity of business organization and business software.
