A novel polygonal finite element method （PFEM） based on partition of unity is proposed, termed the virtual node method （VNM）. To test the performance of the present method, numerical examples are given for solid m...A novel polygonal finite element method （PFEM） based on partition of unity is proposed, termed the virtual node method （VNM）. To test the performance of the present method, numerical examples are given for solid mechanics problems. With a polynomial form, the VNM achieves better results than those of traditional PFEMs, including the Wachspress method and the mean value method in standard patch tests. Compared with the standard triangular FEM, the VNM can achieve better accuracy. With the ability to construct shape functions on polygonal elements, the VNM provides greater flexibility in mesh generation. Therefore, several fracture problems are studied to demonstrate the potential implementation. With the advantage of the VNM, the convenient refinement and remeshing strategy are applied.展开更多
The number of IPv6 routes in todays backbone routers has grown rapidly,which has put tremendous pressure on route lookup and storage.Based on the analysis of IPv6 address prefix length and distribution characteristics...The number of IPv6 routes in todays backbone routers has grown rapidly,which has put tremendous pressure on route lookup and storage.Based on the analysis of IPv6 address prefix length and distribution characteristics,this paper proposes an IPv6 route lookup architecture called LPR-Trie.The core idea of the algorithm is to utilize more spaces and accelerate routing lookup.Moreover,we put forward the concept of virtual nodes,and leverage the link between virtual nodes and ordinary nodes to accelerate routing lookup.We provide the longest prefix routing entry(LPR)calculation algorithm to achieve the longest prefix match.The experimental results show that the virtual node mechanism increases the search speed up to 244%,and the virtual nodes have better stability by setting an appropriate keep-alive time according to the characteristics of actual traffic.This paper shows that our design improves the routing lookup speed and have better memory utilization.展开更多
A virtual node placement strategy based on service-aware is proposed for an information acquisition platform. The performance preferences and types of services in the information acquisition platform are analyzed as w...A virtual node placement strategy based on service-aware is proposed for an information acquisition platform. The performance preferences and types of services in the information acquisition platform are analyzed as well as a comparison of the running time of services both in virtual node centralized and decentralized placing. All physical hosts are divided into different sub-clusters by using the analytic hierarchy process( AHP),in order to fit service of different performance preferences. In the sub-cluster,both load balance and quality of service are taken into account. Comparing with the heuristic algorithm,the experiment results show that the proposed placement strategy is running for a shorter time. And comparing with the virtual node placement strategy provided by OpenStack,the experiment results show that the proposed placement strategy can improve the execution speed of service in the information acquisition platform,and also can balance the load which improves resources utilization.展开更多
This paper proposed a multi-domain virtual network embedding algorithm based on multi-controller SDN architecture. The local controller first selects candidate substrate nodes for each virtual node in the domain. Then...This paper proposed a multi-domain virtual network embedding algorithm based on multi-controller SDN architecture. The local controller first selects candidate substrate nodes for each virtual node in the domain. Then the global controller abstracts substrate network topology based on the candidate nodes and boundary nodes of each domain, and applies Particle Swarm Optimization Algorithm on it to divide virtual network requests. Each local controller then embeds the virtual nodes of the divided single-domain virtual network requests in the domain, and cooperates with other local controllers to embed the inter-domain virtual links. Simulation experimental results show that the proposed algorithm has good performance in reducing embedding cost with good stability and scalability.展开更多
Concepts for a virtual 3D space and a hyper-sphere are proposed and the formulae for determining the computable nodes of the mesh are derived.Then a new optimization design method('Virtual Mesh Method'or V.M.M...Concepts for a virtual 3D space and a hyper-sphere are proposed and the formulae for determining the computable nodes of the mesh are derived.Then a new optimization design method('Virtual Mesh Method'or V.M.M)is developed.Three examples are given,showing that the method proposed is especially suitable for the optimized design of complex structures,and that the global approximate optimal solution can be searched with remarkably reduced computational work.展开更多
Based on the analysis of characteristic of cable harness planning in virtual environment,a discrete control node modeling (DCNM) method of cable harness in virtual environment and the cable harness assembly routing te...Based on the analysis of characteristic of cable harness planning in virtual environment,a discrete control node modeling (DCNM) method of cable harness in virtual environment and the cable harness assembly routing technique based on it are proposed. DCNM converts a cable harness into continuous flexed line segments connected by a series of section center points,and the design can realize cable harness planning through controlling those control nodes. This method of cable harness routing in the virtual environment breaks the status that virtual assembly process planning is just suitable for the rigid components at present,and impulse the virtual assembly process planning to be more practical. Relation algorithms have been verified in a self-developed system named virtual cable harness assembly planning (VCHAP) system,and this VCHAP system has been applied in assembly process planning of aerospace-related products.展开更多
文摘A novel polygonal finite element method （PFEM） based on partition of unity is proposed, termed the virtual node method （VNM）. To test the performance of the present method, numerical examples are given for solid mechanics problems. With a polynomial form, the VNM achieves better results than those of traditional PFEMs, including the Wachspress method and the mean value method in standard patch tests. Compared with the standard triangular FEM, the VNM can achieve better accuracy. With the ability to construct shape functions on polygonal elements, the VNM provides greater flexibility in mesh generation. Therefore, several fracture problems are studied to demonstrate the potential implementation. With the advantage of the VNM, the convenient refinement and remeshing strategy are applied.
基金support from the National Natural Science Foundation of China (61872252)National Key Research and Development Program of China (2018YFB1800403)+1 种基金the Beijing Natural Science Foundation (4202012)the Science and Technology Project of Beijing Municipal Commission of Education in China (KM201810028017)
文摘The number of IPv6 routes in todays backbone routers has grown rapidly,which has put tremendous pressure on route lookup and storage.Based on the analysis of IPv6 address prefix length and distribution characteristics,this paper proposes an IPv6 route lookup architecture called LPR-Trie.The core idea of the algorithm is to utilize more spaces and accelerate routing lookup.Moreover,we put forward the concept of virtual nodes,and leverage the link between virtual nodes and ordinary nodes to accelerate routing lookup.We provide the longest prefix routing entry(LPR)calculation algorithm to achieve the longest prefix match.The experimental results show that the virtual node mechanism increases the search speed up to 244%,and the virtual nodes have better stability by setting an appropriate keep-alive time according to the characteristics of actual traffic.This paper shows that our design improves the routing lookup speed and have better memory utilization.
基金Supported by the National Natural Science Foundation of China(No.61100189,61370215,61370211,61402137)the National Key Technology R&D Program(No.2012BAH45B01)the Open Project Foundation of Information Security Evaluation Center of Civil Aviation,Civil Aviation University of China(No.CAAC-ISECCA-201703)
文摘A virtual node placement strategy based on service-aware is proposed for an information acquisition platform. The performance preferences and types of services in the information acquisition platform are analyzed as well as a comparison of the running time of services both in virtual node centralized and decentralized placing. All physical hosts are divided into different sub-clusters by using the analytic hierarchy process( AHP),in order to fit service of different performance preferences. In the sub-cluster,both load balance and quality of service are taken into account. Comparing with the heuristic algorithm,the experiment results show that the proposed placement strategy is running for a shorter time. And comparing with the virtual node placement strategy provided by OpenStack,the experiment results show that the proposed placement strategy can improve the execution speed of service in the information acquisition platform,and also can balance the load which improves resources utilization.
基金supported by "the Fundamental Research Funds for the Central Universities" of China University of Petroleum (East China) (Grant No. 18CX02139A)the National Natural Science Foundation of China (Grant No. 61471056)
文摘This paper proposed a multi-domain virtual network embedding algorithm based on multi-controller SDN architecture. The local controller first selects candidate substrate nodes for each virtual node in the domain. Then the global controller abstracts substrate network topology based on the candidate nodes and boundary nodes of each domain, and applies Particle Swarm Optimization Algorithm on it to divide virtual network requests. Each local controller then embeds the virtual nodes of the divided single-domain virtual network requests in the domain, and cooperates with other local controllers to embed the inter-domain virtual links. Simulation experimental results show that the proposed algorithm has good performance in reducing embedding cost with good stability and scalability.
基金Project supported by the Natural Science Foundation of Henan Province,China(No.0311010400).
文摘Concepts for a virtual 3D space and a hyper-sphere are proposed and the formulae for determining the computable nodes of the mesh are derived.Then a new optimization design method('Virtual Mesh Method'or V.M.M)is developed.Three examples are given,showing that the method proposed is especially suitable for the optimized design of complex structures,and that the global approximate optimal solution can be searched with remarkably reduced computational work.
基金Sponsored by the National Natural Science Foundation,China(No.50475162)
文摘Based on the analysis of characteristic of cable harness planning in virtual environment,a discrete control node modeling (DCNM) method of cable harness in virtual environment and the cable harness assembly routing technique based on it are proposed. DCNM converts a cable harness into continuous flexed line segments connected by a series of section center points,and the design can realize cable harness planning through controlling those control nodes. This method of cable harness routing in the virtual environment breaks the status that virtual assembly process planning is just suitable for the rigid components at present,and impulse the virtual assembly process planning to be more practical. Relation algorithms have been verified in a self-developed system named virtual cable harness assembly planning (VCHAP) system,and this VCHAP system has been applied in assembly process planning of aerospace-related products.
