Most transactional memory (TM) research focused on multi-core processors, and others investigated at the clusters, leaving the area of non-uniform memory access (NUMA) system unexplored. The existing TM implementation...Most transactional memory (TM) research focused on multi-core processors, and others investigated at the clusters, leaving the area of non-uniform memory access (NUMA) system unexplored. The existing TM implementations made significant performance degradation on NUMA system because they ignored the slower remote memory access. To solve this problem, a latency-based conflict detection and a forecasting-based conflict prevention method were proposed. Using these techniques, the NUMA aware TM system was presented. By reducing the remote memory access and the abort rate of transaction, the experiment results show that the NUMA aware strategies present good practical TM performance on NUMA system.展开更多
The conflict detection and resolution in collaborative design is a key issue to maintain multi disciplinary design consistency. This paper proposes a new method for conflict detection and resolution based on constrain...The conflict detection and resolution in collaborative design is a key issue to maintain multi disciplinary design consistency. This paper proposes a new method for conflict detection and resolution based on constraint satisfaction technique. The representation of design constraint, the interval arithmetic of the constraint satisfaction problem CSP and the conflict resolution strategy based on constraint relaxation and adjustment are introduced. A constraint satisfaction based conflict detection and resolution tool CSCDR is then developed. It can help collaborative designers to detect and resolve the conflicts in time in the early stage of the design process so that the unnecessary design iteration and repeated negotiation are avoided and the design efficiency is then much improved. A design case illustrates the effectiveness of CSCDR.展开更多
This paper analyzes conflict features in architecture pipe routing,and builds a pipe routing design conflict model by taking into account of discrete nominal internal diameter selection of pipes,material costs,and con...This paper analyzes conflict features in architecture pipe routing,and builds a pipe routing design conflict model by taking into account of discrete nominal internal diameter selection of pipes,material costs,and conflict solution sequence.Considering pipe routing as an assembling process,a conflict detection approach for pipe routing in collaborative architectural design is proposed based on an aforementioned model.Constraint network is used to describe the relationship among pipe routing design parameters and constraints;design conflicts are detected by matching designers' input and constraint network;and detected design conflicts are reordered according to the number of pipe parameters in conflicts.In order to support the collaborative requirement of pipe routing design,a prototype system using browser/server architecture is developed.An illustrative example of water pipe routing in a room is used to show the effectiveness and efficiency of the approach.展开更多
Engineering-oriented constraint of harness technology has much information and project information presents progressive changes along with the design. Therefore, how to handle conflict resolution quickly is a problem ...Engineering-oriented constraint of harness technology has much information and project information presents progressive changes along with the design. Therefore, how to handle conflict resolution quickly is a problem to be solved. Process model of con- flict detection is put forward according to characteristics of harness technology design engineering-oriented constraint, and then two problems of how to conduct conflict positioning and judgment of constraint rules are introduced in this paper. Afterwards in this pa- per, constraint information directed acyclic graph is established by classified project constraint information to solve the conflict posi- tioning problem; solution of constraint satisfaction problem is applied to realize judgment problem of constraint rules. Finally, exam- ple is used to analyze the method in this paper to further verify the correctness and effectiveness of this method.展开更多
Policy conflicts may cause substantial economic losses.Although a large amount of effort has been spent on detecting intra-domain policy conflict,it can not detect conflicts of heterogeneous policies.In this paper,con...Policy conflicts may cause substantial economic losses.Although a large amount of effort has been spent on detecting intra-domain policy conflict,it can not detect conflicts of heterogeneous policies.In this paper,considering background knowledge,we propose a conflict detection mechanism to search and locate conflicts of heterogeneous policies.First,we propose a general access control model to describe authorization mechanisms of cloud service and a translation scheme designed to translate a cloud service policy to an Extensible Access Control Markup Language(XACML)policy.Then the scheme based on Multi-terminal Multi-data-type Interval Decision Diagram(MTMIDD)and Extended MTMIDD(X-MTMIDD)is designed to represent XACML policy and search the conflict among heterogeneous policies.To reduce the rate of false positives,the description logic is used to represent XACML policy and eliminate false conflicts.Experimental results show the efficiency of our scheme.展开更多
The global view of firewall policy conflict is important for administrators to optimize the policy.It has been lack of appropriate firewall policy global conflict analysis,existing methods focus on local conflict dete...The global view of firewall policy conflict is important for administrators to optimize the policy.It has been lack of appropriate firewall policy global conflict analysis,existing methods focus on local conflict detection.We research the global conflict detection algorithm in this paper.We presented a semantic model that captures more complete classifications of the policy using knowledge concept in rough set.Based on this model,we presented the global conflict formal model,and represent it with OBDD(Ordered Binary Decision Diagram).Then we developed GFPCDA(Global Firewall Policy Conflict Detection Algorithm) algorithm to detect global conflict.In experiment,we evaluated the usability of our semantic model by eliminating the false positives and false negatives caused by incomplete policy semantic model,of a classical algorithm.We compared this algorithm with GFPCDA algorithm.The results show that GFPCDA detects conflicts more precisely and independently,and has better performance.展开更多
To the issues of low efficiency of conflict resolution method in collaborative design, we proposed a method, which is conflict resolution about collaborative design based on grid services.It uses the grid services fro...To the issues of low efficiency of conflict resolution method in collaborative design, we proposed a method, which is conflict resolution about collaborative design based on grid services.It uses the grid services from the current design points, uses the method of retrospective thinking to find the conflict point by detecting, and then uses the corresponding method to resolve the conflict point according to the conflict characteristic, after that carried on the conflict detection again. If there is still the conflict, resolve the conflict point again, until the conflict no longer exists. This method combines various traditional resolution methods, makes full use of the grid idle high-performance large-scale sharing resources. With this method the collaborative design conflict resolution cost reduced and the conflict resolution efficiency was raised. And then the problem which is not handled completely was then solved, so that the conflict resolution Quality was guaranteed.展开更多
Modern day products are usually designed cooperatively by groups of experts, each with his own areas of expertise. Because of different viewpoint, evaluation standard and domain knowledge of these design groups in col...Modern day products are usually designed cooperatively by groups of experts, each with his own areas of expertise. Because of different viewpoint, evaluation standard and domain knowledge of these design groups in collaborative design system, conflict is unavoidable. In this paper, an integration conflict management system (ICMS) was presented from the aspect of all life cycle. A hierarchical constraint network was introduced to detect the conflicts. Three conflict types were classified in ICMS and different type of conflict was submitted to different resolution strategy, constraint relaxation to data conflict and knowlegdge based reasoning to knowledge conflict or schema conflict. To those conflicts hard to be resolved with the above two strategies, an arbitration was used for the conflict resolution. ICMS also provided interface with other collaborative systems such as CAE, CAD to improve the efficiency of collaborative design system.展开更多
随着区块链技术应用的普及,联盟链Hyperledger Fabric(简称Fabric)已成为知名区块链开源平台,并得到广泛关注.然而Fabric仍受困于并发事务间冲突问题,冲突发生时会引发大量无效交易上链,导致吞吐量下降,阻碍其发展.对于该问题,现有面向...随着区块链技术应用的普及,联盟链Hyperledger Fabric(简称Fabric)已成为知名区块链开源平台,并得到广泛关注.然而Fabric仍受困于并发事务间冲突问题,冲突发生时会引发大量无效交易上链,导致吞吐量下降,阻碍其发展.对于该问题,现有面向块内冲突的方案缺乏高效的冲突检测和避免方法,同时现有研究往往忽略区块间冲突对吞吐量的不利影响.提出了一种Fabric的优化方案Fabric-HT(fabric with high throughput),从区块内和区块间2方面入手,有效降低事务间并发冲突和提高系统吞吐量.针对区块内事务冲突,提出了一种事务调度机制,根据块内冲突事务集定义了一种高效数据结构——依赖关系链,识别具有“危险结构”的事务并提前中止,合理调度事务和消除冲突;针对区块间事务冲突,将冲突事务检测提前至排序节点完成,建立以“推送-匹配”为核心的冲突事务早期避免机制.在多场景下开展大量实验,结果表明Fabric-HT在吞吐量、事务中止率、事务平均执行时间、无效事务空间占用率等方面均优于对比方案.Fabric-HT吞吐量最高可达Fabric的9.51倍,是最新优化方案FabricSharp的1.18倍;空间利用率上相比FabricSharp提升了14%.此外,Fabric-HT也表现出较好的鲁棒性和抗攻击能力.展开更多
基金Projects(61003075, 61170261) supported by the National Natural Science Foundation of China
文摘Most transactional memory (TM) research focused on multi-core processors, and others investigated at the clusters, leaving the area of non-uniform memory access (NUMA) system unexplored. The existing TM implementations made significant performance degradation on NUMA system because they ignored the slower remote memory access. To solve this problem, a latency-based conflict detection and a forecasting-based conflict prevention method were proposed. Using these techniques, the NUMA aware TM system was presented. By reducing the remote memory access and the abort rate of transaction, the experiment results show that the NUMA aware strategies present good practical TM performance on NUMA system.
文摘The conflict detection and resolution in collaborative design is a key issue to maintain multi disciplinary design consistency. This paper proposes a new method for conflict detection and resolution based on constraint satisfaction technique. The representation of design constraint, the interval arithmetic of the constraint satisfaction problem CSP and the conflict resolution strategy based on constraint relaxation and adjustment are introduced. A constraint satisfaction based conflict detection and resolution tool CSCDR is then developed. It can help collaborative designers to detect and resolve the conflicts in time in the early stage of the design process so that the unnecessary design iteration and repeated negotiation are avoided and the design efficiency is then much improved. A design case illustrates the effectiveness of CSCDR.
基金Supported by the National High Technology Research and Development Programme of China(No.2006AA04Z112)the National Natural Science Foundation of China(No.51175287)the National S&T Major Program(No.2009ZX02001-003)
文摘This paper analyzes conflict features in architecture pipe routing,and builds a pipe routing design conflict model by taking into account of discrete nominal internal diameter selection of pipes,material costs,and conflict solution sequence.Considering pipe routing as an assembling process,a conflict detection approach for pipe routing in collaborative architectural design is proposed based on an aforementioned model.Constraint network is used to describe the relationship among pipe routing design parameters and constraints;design conflicts are detected by matching designers' input and constraint network;and detected design conflicts are reordered according to the number of pipe parameters in conflicts.In order to support the collaborative requirement of pipe routing design,a prototype system using browser/server architecture is developed.An illustrative example of water pipe routing in a room is used to show the effectiveness and efficiency of the approach.
基金Supported by Chinese national Science Foundation (No.61070124)the Fundamental Research Funds for the Central Universities(No.2012HGBZ0195)
文摘Engineering-oriented constraint of harness technology has much information and project information presents progressive changes along with the design. Therefore, how to handle conflict resolution quickly is a problem to be solved. Process model of con- flict detection is put forward according to characteristics of harness technology design engineering-oriented constraint, and then two problems of how to conduct conflict positioning and judgment of constraint rules are introduced in this paper. Afterwards in this pa- per, constraint information directed acyclic graph is established by classified project constraint information to solve the conflict posi- tioning problem; solution of constraint satisfaction problem is applied to realize judgment problem of constraint rules. Finally, exam- ple is used to analyze the method in this paper to further verify the correctness and effectiveness of this method.
基金This work has been funded by the National Natural Science Foundation of China(No.U1836203)the Shandong Provincial Key Research and Development Program(2019JZZY20127).
文摘Policy conflicts may cause substantial economic losses.Although a large amount of effort has been spent on detecting intra-domain policy conflict,it can not detect conflicts of heterogeneous policies.In this paper,considering background knowledge,we propose a conflict detection mechanism to search and locate conflicts of heterogeneous policies.First,we propose a general access control model to describe authorization mechanisms of cloud service and a translation scheme designed to translate a cloud service policy to an Extensible Access Control Markup Language(XACML)policy.Then the scheme based on Multi-terminal Multi-data-type Interval Decision Diagram(MTMIDD)and Extended MTMIDD(X-MTMIDD)is designed to represent XACML policy and search the conflict among heterogeneous policies.To reduce the rate of false positives,the description logic is used to represent XACML policy and eliminate false conflicts.Experimental results show the efficiency of our scheme.
基金supported by the National Nature Science Foundation of China under Grant No.61170295 the Project of National ministry under Grant No.A2120110006+2 种基金 the Co-Funding Project of Beijing Municipal Education Commission under Grant No.JD100060630 the Beijing Education Committee General Program under Grant No. KM201211232010 the National Nature Science Foundation of China under Grant NO. 61370065
文摘The global view of firewall policy conflict is important for administrators to optimize the policy.It has been lack of appropriate firewall policy global conflict analysis,existing methods focus on local conflict detection.We research the global conflict detection algorithm in this paper.We presented a semantic model that captures more complete classifications of the policy using knowledge concept in rough set.Based on this model,we presented the global conflict formal model,and represent it with OBDD(Ordered Binary Decision Diagram).Then we developed GFPCDA(Global Firewall Policy Conflict Detection Algorithm) algorithm to detect global conflict.In experiment,we evaluated the usability of our semantic model by eliminating the false positives and false negatives caused by incomplete policy semantic model,of a classical algorithm.We compared this algorithm with GFPCDA algorithm.The results show that GFPCDA detects conflicts more precisely and independently,and has better performance.
基金the National High Technology Research and Development Program of China (863 Program) (2002AA414060, 2001AA411310)the Key Science and Technology Program of Shaanxi Province (2006K05- G10)
文摘To the issues of low efficiency of conflict resolution method in collaborative design, we proposed a method, which is conflict resolution about collaborative design based on grid services.It uses the grid services from the current design points, uses the method of retrospective thinking to find the conflict point by detecting, and then uses the corresponding method to resolve the conflict point according to the conflict characteristic, after that carried on the conflict detection again. If there is still the conflict, resolve the conflict point again, until the conflict no longer exists. This method combines various traditional resolution methods, makes full use of the grid idle high-performance large-scale sharing resources. With this method the collaborative design conflict resolution cost reduced and the conflict resolution efficiency was raised. And then the problem which is not handled completely was then solved, so that the conflict resolution Quality was guaranteed.
文摘Modern day products are usually designed cooperatively by groups of experts, each with his own areas of expertise. Because of different viewpoint, evaluation standard and domain knowledge of these design groups in collaborative design system, conflict is unavoidable. In this paper, an integration conflict management system (ICMS) was presented from the aspect of all life cycle. A hierarchical constraint network was introduced to detect the conflicts. Three conflict types were classified in ICMS and different type of conflict was submitted to different resolution strategy, constraint relaxation to data conflict and knowlegdge based reasoning to knowledge conflict or schema conflict. To those conflicts hard to be resolved with the above two strategies, an arbitration was used for the conflict resolution. ICMS also provided interface with other collaborative systems such as CAE, CAD to improve the efficiency of collaborative design system.
文摘随着区块链技术应用的普及,联盟链Hyperledger Fabric(简称Fabric)已成为知名区块链开源平台,并得到广泛关注.然而Fabric仍受困于并发事务间冲突问题,冲突发生时会引发大量无效交易上链,导致吞吐量下降,阻碍其发展.对于该问题,现有面向块内冲突的方案缺乏高效的冲突检测和避免方法,同时现有研究往往忽略区块间冲突对吞吐量的不利影响.提出了一种Fabric的优化方案Fabric-HT(fabric with high throughput),从区块内和区块间2方面入手,有效降低事务间并发冲突和提高系统吞吐量.针对区块内事务冲突,提出了一种事务调度机制,根据块内冲突事务集定义了一种高效数据结构——依赖关系链,识别具有“危险结构”的事务并提前中止,合理调度事务和消除冲突;针对区块间事务冲突,将冲突事务检测提前至排序节点完成,建立以“推送-匹配”为核心的冲突事务早期避免机制.在多场景下开展大量实验,结果表明Fabric-HT在吞吐量、事务中止率、事务平均执行时间、无效事务空间占用率等方面均优于对比方案.Fabric-HT吞吐量最高可达Fabric的9.51倍,是最新优化方案FabricSharp的1.18倍;空间利用率上相比FabricSharp提升了14%.此外,Fabric-HT也表现出较好的鲁棒性和抗攻击能力.
