The use of digital library services within the network and the external aspects, analysis of university library network security risks faced by the hardware, software, security risk, technical risk, management risk and the risk of external attacks and other major security risk. Combination of network security technologies, were put forward their own coping strategies. Focus on analysis of hacker attacks and network viruses control methods, including the use of anti-virus protection software, the use of firewall technology, encryption and authentication technology, intrusion detection, VLAN technology, content inspection and monitoring technology, and virtual honey pot technologies. Library network systems only to achieve security of the nature of the equipment, Network technology, professional and management standardization, in order to effectively avoid the risk of a variety of network security and ensure the normal operation of network systems, research on prevention and control of universities Digital library network security risks with a reference and guide.

The efficiency of the intrusion detection is mainly depended on the dimension of data features. By using the gradually feature removal method, 19 critical features are chosen to represent for the various network visit. With the combination of clustering method, ant colony algorithm and support vector machine (SVM), an efficient and reliable classifier is developed to judge a network visit to be normal or not. Moreover, the accuracy achieves 98.6249% in 10-fold cross validation and the average Matthews correlation coefficient (MCC) achieves 0.861161.

Analysis of PGP content of the protocol, the protocol there is a public key distribution protocol system loopholes, through analysis, the protocol could not resist the middle attack. In this paper proposed a method that security of cryptographic algorithms in the original basis of the above, from the protocol itself to strengthen security. Improved PGP cryptosystem from the point of view is difficult to break.

With the rapid development of computer networks, network security has become a hot topic of concern to people, not just a simple network security threat network needs normal people, but also the pursuit of networking technology in innovative source of power. To address this issue, this article on network security solution to the problem definition and further discussion, and propose how to establish network security management.

The paper deals with the shortest path problem with Constraints, and it is NP-complete problem. The problem is formulated as an optimization model. To solve this model Lagrangean relaxation algorithm is adopted. For the solution of the dual problem a subgradient method is used. The general algorithm steps for our problem are presented, and a numerical example on communication network is given to illustrate the effectiveness of the algorithm.

With my school of Information and Computer Science "Cryptography" course teaching practice, this mainly from the theoretical teaching, laboratory teaching two aspects of cryptography in some of the feasibility of teaching methods are discussed, and teaching content design. Teaching practice in recent years show that the method can receive better teaching results. Since 2004 our school opened, "Cryptography" course, in practice, found that each year thesis topics of time, there were many students choose the topics and cryptography-related topics as a graduation project, and can pass defense, which can also prove that the teaching methods discussed in this article can receive good results.

Over the past 20 years, IPv4 network development for the computer to make a great contribution, however, gradually revealed its flaws. IPv6 to replace IPv4 with its inevitability. However, because these two protocols are very different. And the transition to equipment and software with updates and upgrades, and how to minimize the cost to achieve the campus network from IPv4 to IPv6 transition is the key. This article focuses on the excessive cost of programs and methods to achieve the minimum.

With the development of medical imaging technology and the popularity of the hospital information network, in a modern hospital patients a day will produce a large number of physiological and pathological contain and anatomical information, For the difficulty of medical image watermarking, this paper presents a digital watermarking method based on SVD, the method was simple, clear principles from the experimental results, the method can meet the actual demand.

The facility location problems have been applied extensively in practice. We describe a facility location problem with stochastic demand based chance-constrained programming model, and formulate an approach to conversion of the chance constraints to their respective deterministic equivalents. A Lagrangian relaxation approach using subgradient algorithm is adopted and designed for the equivalent model. The performance of the proposed method is tested by a numerical experiment, and show the effectiveness of the proposed algorithm.