Considering the deviation in content of community detection resulting from the tow accuracy of resource relevance, an algorithm based on the topology of sites and the similarity between their topics is proposed. With topic content factors fully considered, this algorithm can search for topically similar site clusters on the premise of inter-site topology. The experimental results show that the algorithm can generate a more accurate result of detection in the real network.
The intrinsic routing policy of NS2—a network simulation tool— based on flat or hierarchical address has the disadvantage such as small topology scale,high resource consumption,low efficiency and so on.This paper proposes an IP based hierarchical routing strategy in network simulation to extend the topology scale and improve performance in simulating.Firstly,a stratification mechanism to identify IP address of nodes is described.Then,an algorithm of packet transmitting method(PTM) is presented for packet forwarding in the same subnet.Finally,algorithms of region partition(RP),routing computation based on region division(RCBRD) and routing distribution(RD) is proposed to implement regional segmentation,route calculation and route distribution for forwarding packets in different subnets respectively.The experiment results show that under the same condition,compared with plane address,the topology scale of the network simulation is extended two times and the consumption of time and memory during simulation is reduced by approximately 73%and 45.8% respectively.Compared with hierarchical address,the topology scale of the network simulation is expanded by more than 50%,and the consumption of time and memory is reduced by about 59.2% and 25% respectively.In addition,along with the growth of the node size,the proportion of reducing total simulation time and memory consumption would gradually increase.
针对DNS可解析性量化评估问题,提出了基于命题逻辑的DNS可解析性量化评估方法。该方法通过对域名解析依赖关系的分析建立域名解析依赖关系图,结合命题逻辑将域名对DNS服务器的依赖性转换为逻辑图,进而将域名的可解析性问题转换为数理逻辑中的命题公式的可满足性问题;通过对命题公式进行析取范式的转换和对命题变项数最少的简单合取范式的分析,获取域名可解析的最小DNS服务器组合,从而指导DNS服务器的布置和规划;通过对命题公式进行合取范式的转换和对命题变项数最少的简单析取范式的分析,获取域名不可解析的最小DNS服务器组合,从而对这些DNS服务器进行重点防护。以Alex Top 1000域名为例分析了解析依赖关系,经统计计算发现,Alex Top 1000域名解析平均依赖DNS数量为5.58个;域名解析依赖的最小服务器组合在[1,4]区间内,平均值为1.41个;破坏域名解析的最小服务器组合在[1,6]区间内,平均值为2.44个。
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.
