Abstract With the emerging of peer-to-peer (P2P) network in recent years, unsafety problems underlying becomes more obvious, such as dishonest recommendation, collusive cheat and complex strategic attack behavior. But the current trust model is able to process the above problems in a better way. Thus this study proposes a credit-based distributed trust management model for P2P, named RA Trust and applies... With the emerging of peer-to-peer (P2P) network in recent years, unsafety problems underlying becomes more obvious, such as dishonest recommendation, collusive cheat and complex strategic attack behavior. But the current trust model is able to process the above problems in a better way. Thus this study proposes a credit-based distributed trust management model for P2P, named RA Trust and applies it to quantify and evaluate credibility of peer. In construction of trust model, we use time interval to mark time property of experience and recommendation and describe the final trust level of peer using peer credibility, short-term trust and long-term trust as well as trust measurement of peer in a more accurate way by introducing trust deviation value and trust abuse value. Results suggest that, RA Trust has better dynamic adaptive ability and can effectively process strategic behavioral changes of dynamic malicious peer and attack of dishonest feedback on system. Read More Read Less

Abstract In recent years, because of anonymity and dynamics, P2P network have suffered from more and more security problems, which means that traditional trust management cannot be well adapted to P2P network environment, making dynamic trust a new research focus. Based on trust mechanism in P2P environment, this paper analyzes the trust of consumption node to service node, coming upon an... In recent years, because of anonymity and dynamics, P2P network have suffered from more and more security problems, which means that traditional trust management cannot be well adapted to P2P network environment, making dynamic trust a new research focus. Based on trust mechanism in P2P environment, this paper analyzes the trust of consumption node to service node, coming upon an advanced trust evaluation model pointing at information exchange among nodes to evaluate credit changes when service provider exchanging information. With risk mechanism, this paper also analyzes risks of information exchange among nodes in P2P network. It is proved that the model mentioned can effectively resist credit speculation and periodic deception. Read More Read Less

Abstract In today’s society, the internet was increasingly expanding the scale of the computer network, the structure of the network has become more and more complex, the network management system must have a higher intelligence. A large amount of data had been processed in the network management system, and the application rules on data processing are the two most basic elements, and the database... In today’s society, the internet was increasingly expanding the scale of the computer network, the structure of the network has become more and more complex, the network management system must have a higher intelligence. A large amount of data had been processed in the network management system, and the application rules on data processing are the two most basic elements, and the database had provided a technical solution to achieve the function of these basic elements. This paper discussed the network management system, the basic function of network protocols and network management MIB databases, the ERC plus method of database design are discussed, and the application example is given. The article also analyzed the adaptability of network management application on database. The design and maintenance of the network system is very useful. Read More Read Less

Abstract Cloud computing is consisted of physical data centers each of which including hundreds or thousands of computers. A key technology which has enabled cloud computing feasible, is virtualization. Virtualization allows us to separate virtual machines in a way that each of these so-called virtualized machines can be configured on a number of hosts according to the type of application of the user. It... Cloud computing is consisted of physical data centers each of which including hundreds or thousands of computers. A key technology which has enabled cloud computing feasible, is virtualization. Virtualization allows us to separate virtual machines in a way that each of these so-called virtualized machines can be configured on a number of hosts according to the type of application of the user. It is also possible to dynamically alter the allocated resources of a virtual machine. Different methods of energy saving in data centers can be divided to three general categories: 1) energy saving methods based on balancing the loads of resources; 2) scheduling by the help of hardware facilities; 3) reducing the consumption of energy through being aware of thermal characteristics of the environment. One of the most important challenges in terms of cloud computing is to maintain an optimized load balance in cloud environment on servers because this issue is critical for energy consumption. Since load balance algorithms depend on the current behavior of the system, they act dynamically. Important factors which should be taken into account while developing such types of algorithms include load estimation, load ratio, adaptability of different systems, performance of the system, interaction between nods, scheduling, nature of the transferred service, selecting nodes and etc. By taking a detailed look on previous methods and challenges of energy saving in cloud networks, we provide a hybrid method which enables us to save energy through finding a suitable configuration for placement of virtual machines and through being aware of special features of virtual environments for scheduling and balancing their dynamic loads by the help of live migration method. Read More Read Less