Firstly, a multilevel trust algorithm for MANET （mobile ad hoe networks） is presented in this paper and the trust level is defined as a three-tuple type in this multilevel trust algorithm. The paper introduces the m...Firstly, a multilevel trust algorithm for MANET （mobile ad hoe networks） is presented in this paper and the trust level is defined as a three-tuple type in this multilevel trust algorithm. The paper introduces the multilevel trust into MANET, thereby controlling restricted classified information flows among nodes that have different trust levels. Secondly, the infrastructure of MANET that suit to our multi-level trust is presented, Some conclusions are given at lastly.展开更多
In this paper, a new trust region algorithm for unconstrained LC1 optimization problems is given. Compare with those existing trust regiion methods, this algorithm has a different feature: it obtains a stepsize at eac...In this paper, a new trust region algorithm for unconstrained LC1 optimization problems is given. Compare with those existing trust regiion methods, this algorithm has a different feature: it obtains a stepsize at each iteration not by soloving a quadratic subproblem with a trust region bound, but by solving a system of linear equations. Thus it reduces computational complexity and improves computation efficiency. It is proven that this algorithm is globally convergent and locally superlinear under some conditions.展开更多
In this paper, we present a new line search and trust region algorithm for unconstrained optimization problems. The trust region center locates at somewhere in the negative gradient direction with the current best ite...In this paper, we present a new line search and trust region algorithm for unconstrained optimization problems. The trust region center locates at somewhere in the negative gradient direction with the current best iterative point being on the boundary. By doing these, the trust region subproblems are constructed at a new way different with the traditional ones. Then, we test the efficiency of the new line search and trust region algorithm on some standard benchmarking. The computational results reveal that, for most test problems, the number of function and gradient calculations are reduced significantly.展开更多
The trust in distributed environment is uncertain, which is variation for various factors. This paper introduces TDTM, a model for time-based dynamic trust. Every entity in the distribute environment is endowed with a...The trust in distributed environment is uncertain, which is variation for various factors. This paper introduces TDTM, a model for time-based dynamic trust. Every entity in the distribute environment is endowed with a trust-vector, which figures the trust intensity between this entity and the others. The trust intensity is dynamic due to the time and the inter-operation between two entities, a method is proposed to quantify this change based on the mind of ant colony algorithm and then an algorithm for the transfer of trust relation is also proposed. Furthermore, this paper analyses the influence to the trust intensity among all entities that is aroused by the change of trust intensity between the two entities, and presents an algorithm to resolve the problem. Finally, we show the process of the trusts＇ change that is aroused by the time＇s lapse and the inter-operation through an instance.展开更多
A trust region algorithm for equality constrained optimization is given in this paper.The algorithm does not enforce strict monotonicity of the merit function for every iteration.Global convergence of the algorithm i...A trust region algorithm for equality constrained optimization is given in this paper.The algorithm does not enforce strict monotonicity of the merit function for every iteration.Global convergence of the algorithm is proved under the same conditions of usual trust region method.展开更多
In the open network environment, malicious attacks to the trust model have become increasingly serious. Compared with single node attacks, collusion attacks do more harm to the trust model. To solve this problem, a co...In the open network environment, malicious attacks to the trust model have become increasingly serious. Compared with single node attacks, collusion attacks do more harm to the trust model. To solve this problem, a collusion detector based on the GN algorithm for the trust evaluation model is proposed in the open Internet environment. By analyzing the behavioral characteristics of collusion groups, the concept of flatting is defined and the G-N community mining algorithm is used to divide suspicious communities. On this basis, a collusion community detector method is proposed based on the breaking strength of suspicious communities. Simulation results show that the model has high recognition accuracy in identifying collusion nodes, so as to effectively defend against malicious attacks of collusion nodes.展开更多
This paper presents a scheme to perform QoS management and assure network security by using the trusted-router based on the Trust Management System.In this trusted-router,every IP packet is forwarded and queued by its...This paper presents a scheme to perform QoS management and assure network security by using the trusted-router based on the Trust Management System.In this trusted-router,every IP packet is forwarded and queued by its trust value,which is the quantification of the network's expectation for this packet's and its owner's behavior in the network.We outline the algorithms to calculate the trust value of the trusted-router and the IP packet.We also introduce the trust-based QoS management algorithm and the deployment of the trusted-routers which carry out this algorithm.The simulation results show that the least trusted IP packets will be dropped to save resources for those highly trusted IP packets.This will ecourage all the elements in the network to keep a good trust record.展开更多
共识算法是一种用于确保区块链网络中所有节点达成一致的方法,常见的有工作量证明(Proof-of-Work,PoW)和权益证明(Proof of Stake,PoS)等,共识机制的优劣影响着区块链系统的性能。为了解决现有区块链共识算法存在的吞吐量较小、时延较...共识算法是一种用于确保区块链网络中所有节点达成一致的方法,常见的有工作量证明(Proof-of-Work,PoW)和权益证明(Proof of Stake,PoS)等,共识机制的优劣影响着区块链系统的性能。为了解决现有区块链共识算法存在的吞吐量较小、时延较长等问题,对区块链中实用拜占庭容错(PBFT)算法进行改进,引入基于Bayes理论的动态信任模型(Dynamic Trust Model),通过节点信任机制改变节点在共识轮中的信任度,并按照信任度进行分组等操作,在保证PBFT稳定性的同时提高了系统可扩展性,且完善了网络节点的加入退出机制,使得网络可拓展性得到提高。通过实验测试,相比传统PBFT,改进后的算法在吞吐量上有25%的提升,在节点数量达到50的情况下时延只有PBFT的一半,所提方法的这两项指标相比HotStuff算法和Paxos算法也有20%~30%的提升。展开更多
In this paper we present a filter-trust-region algorithm for solving LC1 unconstrained optimization problems which uses the second Dini upper directional derivative. We establish the global convergence of the algorith...In this paper we present a filter-trust-region algorithm for solving LC1 unconstrained optimization problems which uses the second Dini upper directional derivative. We establish the global convergence of the algorithm under reasonable assumptions.展开更多
Trust is an important aspect of the design and analysis of secure distributed systems. It is often used informally to designate those portions of a system that must function correctly in order to achieve the desired o...Trust is an important aspect of the design and analysis of secure distributed systems. It is often used informally to designate those portions of a system that must function correctly in order to achieve the desired outcome. But it is a notoriously diffcult notion to formalize. What are the properties of trust? How is it learned, propagated, and utilized successfully? How can it be modeled? How can a trust model be used to derive protocols that are effcient and reliable when employed in today's expansive networks? Past work has been concerned with only a few of these issues, without concentrating on the need for a comprehensive approach to trust modeling. In this paper, we take a first step in that direction by studying an artificial community of agents that uses a notion of trust to succeed in a game against nature. The model is simple enough to analyze and simulate, but also rich enough to exhibit phenomena of real life interactive communities. The model requires agents to make decisions. To do well, the agents are informed by knowledge gained from their own past experience as well as from the experience of other agents. Communication among agents allows knowledge to propagate faster through the network, which in turn can allow for a more successful community. We analyze the model from both a theoretical and an experimental point of view.展开更多
基金Supported by the National Natural Science Foun-dation of China (60372107) Doctoral Innovative Foundation ofJiangsu Province(46666001) .
文摘Firstly, a multilevel trust algorithm for MANET （mobile ad hoe networks） is presented in this paper and the trust level is defined as a three-tuple type in this multilevel trust algorithm. The paper introduces the multilevel trust into MANET, thereby controlling restricted classified information flows among nodes that have different trust levels. Secondly, the infrastructure of MANET that suit to our multi-level trust is presented, Some conclusions are given at lastly.
文摘In this paper, a new trust region algorithm for unconstrained LC1 optimization problems is given. Compare with those existing trust regiion methods, this algorithm has a different feature: it obtains a stepsize at each iteration not by soloving a quadratic subproblem with a trust region bound, but by solving a system of linear equations. Thus it reduces computational complexity and improves computation efficiency. It is proven that this algorithm is globally convergent and locally superlinear under some conditions.
文摘In this paper, we present a new line search and trust region algorithm for unconstrained optimization problems. The trust region center locates at somewhere in the negative gradient direction with the current best iterative point being on the boundary. By doing these, the trust region subproblems are constructed at a new way different with the traditional ones. Then, we test the efficiency of the new line search and trust region algorithm on some standard benchmarking. The computational results reveal that, for most test problems, the number of function and gradient calculations are reduced significantly.
基金Supported by the National Natural Science Foun-dation of China (60403027) Natural Science Foundation of HubeiProvince (2005ABA258) Open Foundation of State Key Labora-tory of Software Engineering (SKLSE05-07)
文摘The trust in distributed environment is uncertain, which is variation for various factors. This paper introduces TDTM, a model for time-based dynamic trust. Every entity in the distribute environment is endowed with a trust-vector, which figures the trust intensity between this entity and the others. The trust intensity is dynamic due to the time and the inter-operation between two entities, a method is proposed to quantify this change based on the mind of ant colony algorithm and then an algorithm for the transfer of trust relation is also proposed. Furthermore, this paper analyses the influence to the trust intensity among all entities that is aroused by the change of trust intensity between the two entities, and presents an algorithm to resolve the problem. Finally, we show the process of the trusts＇ change that is aroused by the time＇s lapse and the inter-operation through an instance.
文摘A trust region algorithm for equality constrained optimization is given in this paper.The algorithm does not enforce strict monotonicity of the merit function for every iteration.Global convergence of the algorithm is proved under the same conditions of usual trust region method.
基金supported by the National Natural Science Foundation of China(6140224161572260+3 种基金613730176157226161472192)the Scientific&Technological Support Project of Jiangsu Province(BE2015702)
文摘In the open network environment, malicious attacks to the trust model have become increasingly serious. Compared with single node attacks, collusion attacks do more harm to the trust model. To solve this problem, a collusion detector based on the GN algorithm for the trust evaluation model is proposed in the open Internet environment. By analyzing the behavioral characteristics of collusion groups, the concept of flatting is defined and the G-N community mining algorithm is used to divide suspicious communities. On this basis, a collusion community detector method is proposed based on the breaking strength of suspicious communities. Simulation results show that the model has high recognition accuracy in identifying collusion nodes, so as to effectively defend against malicious attacks of collusion nodes.
基金supported by National Key Basic Research Program of China(973 Program)under Grant No.2007CB310704National Natural Science Foundation of China under Grant No.90718001,60973146
文摘This paper presents a scheme to perform QoS management and assure network security by using the trusted-router based on the Trust Management System.In this trusted-router,every IP packet is forwarded and queued by its trust value,which is the quantification of the network's expectation for this packet's and its owner's behavior in the network.We outline the algorithms to calculate the trust value of the trusted-router and the IP packet.We also introduce the trust-based QoS management algorithm and the deployment of the trusted-routers which carry out this algorithm.The simulation results show that the least trusted IP packets will be dropped to save resources for those highly trusted IP packets.This will ecourage all the elements in the network to keep a good trust record.
文摘共识算法是一种用于确保区块链网络中所有节点达成一致的方法,常见的有工作量证明(Proof-of-Work,PoW)和权益证明(Proof of Stake,PoS)等,共识机制的优劣影响着区块链系统的性能。为了解决现有区块链共识算法存在的吞吐量较小、时延较长等问题,对区块链中实用拜占庭容错(PBFT)算法进行改进,引入基于Bayes理论的动态信任模型(Dynamic Trust Model),通过节点信任机制改变节点在共识轮中的信任度,并按照信任度进行分组等操作,在保证PBFT稳定性的同时提高了系统可扩展性,且完善了网络节点的加入退出机制,使得网络可拓展性得到提高。通过实验测试,相比传统PBFT,改进后的算法在吞吐量上有25%的提升,在节点数量达到50的情况下时延只有PBFT的一半,所提方法的这两项指标相比HotStuff算法和Paxos算法也有20%~30%的提升。
基金Supported by CERG: CityU 101005 of the Government of Hong Kong SAR, Chinathe National Natural ScienceFoundation of China, the Specialized Research Fund of Doctoral Program of Higher Education of China (Grant No.20040319003)the Natural Science Fund of Jiangsu Province of China (Grant No. BK2006214)
文摘In this paper we present a filter-trust-region algorithm for solving LC1 unconstrained optimization problems which uses the second Dini upper directional derivative. We establish the global convergence of the algorithm under reasonable assumptions.
文摘Trust is an important aspect of the design and analysis of secure distributed systems. It is often used informally to designate those portions of a system that must function correctly in order to achieve the desired outcome. But it is a notoriously diffcult notion to formalize. What are the properties of trust? How is it learned, propagated, and utilized successfully? How can it be modeled? How can a trust model be used to derive protocols that are effcient and reliable when employed in today's expansive networks? Past work has been concerned with only a few of these issues, without concentrating on the need for a comprehensive approach to trust modeling. In this paper, we take a first step in that direction by studying an artificial community of agents that uses a notion of trust to succeed in a game against nature. The model is simple enough to analyze and simulate, but also rich enough to exhibit phenomena of real life interactive communities. The model requires agents to make decisions. To do well, the agents are informed by knowledge gained from their own past experience as well as from the experience of other agents. Communication among agents allows knowledge to propagate faster through the network, which in turn can allow for a more successful community. We analyze the model from both a theoretical and an experimental point of view.
