In this paper, we propose a retrospective filter trust region algorithm for unconstrained optimization, which is based on the framework of the retrospective trust region method and associated with the technique of the...In this paper, we propose a retrospective filter trust region algorithm for unconstrained optimization, which is based on the framework of the retrospective trust region method and associated with the technique of the multi-dimensional filter. The new algorithm gives a good estimation of trust region radius, relaxes the condition of accepting a trial step for the usual trust region methods. Under reasonable assumptions, we analyze the global convergence of the new method and report the preliminary results of numerical tests. We compare the results with those of the basic trust region algorithm, the filter trust region algorithm and the retrospective trust region algorithm, which shows the effectiveness of the new algorithm.展开更多
从信任的一般涵义出发,引申出电子商务环境下信任的内涵及特点。在此基础上,对常见的三种电子商务模式(B to B、B to C、C to C)的信任状况进行了分析,得出B to B电子商务的信任状况较好,而其他两种模式的信任状况较差的结论,并进一步对...从信任的一般涵义出发,引申出电子商务环境下信任的内涵及特点。在此基础上,对常见的三种电子商务模式(B to B、B to C、C to C)的信任状况进行了分析,得出B to B电子商务的信任状况较好,而其他两种模式的信任状况较差的结论,并进一步对B to C、C to C的信任机制进行了讨论。根据B to C、C to C交易模式的特点,剖析了其信任体系的构成及交易过程中信任机制的作用机理,以期为电子商务信任体系的实证分析做好铺垫,为更好地解决B to C、C to C中存在的信任问题打好基础。展开更多
针对无线传感器网络中节点的安全性及覆盖问题,提出基于节点信任度的三维覆盖算法(three dimensional coverage algorithm based on node trust,NTA3D)。该算法依据虚拟力、网格划分及节点信任度的思想,引入吸引源联合信任度。将待监测...针对无线传感器网络中节点的安全性及覆盖问题,提出基于节点信任度的三维覆盖算法(three dimensional coverage algorithm based on node trust,NTA3D)。该算法依据虚拟力、网格划分及节点信任度的思想,引入吸引源联合信任度。将待监测区域划分成网格,并在每个网格中心部署吸引源。吸引源可以根据网格中的活跃节点计算该网格的联合信任度,并根据联合信任度调度节点,调度结束后工作节点根据其所受合力的大小和方向重新部署。通过实验仿真,证明了该算法能够在保证安全性的前提下有效地提高覆盖率,降低网络能耗。展开更多
In the last few years, cloud computing as a new computing paradigm has gone through significant development, but it is also facing many problems. One of them is the cloud service selection problem. As increasingly boo...In the last few years, cloud computing as a new computing paradigm has gone through significant development, but it is also facing many problems. One of them is the cloud service selection problem. As increasingly boosting cloud services are offered through the internet and some of them may be not reliable or even malicious, how to select trustworthy cloud services for cloud users is a big challenge. In this paper, we propose a multi-dimensional trust-aware cloud service selection mechanism based on evidential reasoning(ER) approach that integrates both perception-based trust value and reputation based trust value, which are derived from direct and indirect trust evidence respectively, to identify trustworthy services. Here, multi-dimensional trust evidence, which reflects the trustworthiness of cloud services from different aspects, is elicited in the form of historical users feedback ratings. Then, the ER approach is applied to aggregate the multi-dimensional trust ratings to obtain the real-time trust value and select the most trustworthy cloud service of certain type for the active users. Finally, the fresh feedback from the active users will update the trust evidence for other service users in the future.展开更多
文摘In this paper, we propose a retrospective filter trust region algorithm for unconstrained optimization, which is based on the framework of the retrospective trust region method and associated with the technique of the multi-dimensional filter. The new algorithm gives a good estimation of trust region radius, relaxes the condition of accepting a trial step for the usual trust region methods. Under reasonable assumptions, we analyze the global convergence of the new method and report the preliminary results of numerical tests. We compare the results with those of the basic trust region algorithm, the filter trust region algorithm and the retrospective trust region algorithm, which shows the effectiveness of the new algorithm.
文摘从信任的一般涵义出发,引申出电子商务环境下信任的内涵及特点。在此基础上,对常见的三种电子商务模式(B to B、B to C、C to C)的信任状况进行了分析,得出B to B电子商务的信任状况较好,而其他两种模式的信任状况较差的结论,并进一步对B to C、C to C的信任机制进行了讨论。根据B to C、C to C交易模式的特点,剖析了其信任体系的构成及交易过程中信任机制的作用机理,以期为电子商务信任体系的实证分析做好铺垫,为更好地解决B to C、C to C中存在的信任问题打好基础。
文摘针对无线传感器网络中节点的安全性及覆盖问题,提出基于节点信任度的三维覆盖算法(three dimensional coverage algorithm based on node trust,NTA3D)。该算法依据虚拟力、网格划分及节点信任度的思想,引入吸引源联合信任度。将待监测区域划分成网格,并在每个网格中心部署吸引源。吸引源可以根据网格中的活跃节点计算该网格的联合信任度,并根据联合信任度调度节点,调度结束后工作节点根据其所受合力的大小和方向重新部署。通过实验仿真,证明了该算法能够在保证安全性的前提下有效地提高覆盖率,降低网络能耗。
基金supported by National Natural Science Foundation of China(Nos.71131002,71071045,71231004 and 71201042)
文摘In the last few years, cloud computing as a new computing paradigm has gone through significant development, but it is also facing many problems. One of them is the cloud service selection problem. As increasingly boosting cloud services are offered through the internet and some of them may be not reliable or even malicious, how to select trustworthy cloud services for cloud users is a big challenge. In this paper, we propose a multi-dimensional trust-aware cloud service selection mechanism based on evidential reasoning(ER) approach that integrates both perception-based trust value and reputation based trust value, which are derived from direct and indirect trust evidence respectively, to identify trustworthy services. Here, multi-dimensional trust evidence, which reflects the trustworthiness of cloud services from different aspects, is elicited in the form of historical users feedback ratings. Then, the ER approach is applied to aggregate the multi-dimensional trust ratings to obtain the real-time trust value and select the most trustworthy cloud service of certain type for the active users. Finally, the fresh feedback from the active users will update the trust evidence for other service users in the future.
