数据库审计在三层架构医院信息系统中的应用

目的:达到对三层网络架构数据库访问、操作、来源等行为进行审计。方法:遵从数据库产生、数据流程和数据通信原理,对数据经过交换机时抓取针对数据库访问的数据包来进行分析。结果:结合医院的实际业务情况,从而设计出切实可用的数据库审计应用系统。结论:数据库审计系统的应用能保障数据库安全,监控医院信息系统中的统方事件,对医院数据安全具有非常重要的作用,且能适用于各类型医院及其他行业的数据库安全应用。

Integrating Factors and Conservation Laws of Generalized Birkhoff System Dynamics in Event Space

In this paper, the conservation laws of generalized Birkhoff system in event space are studied by using the method of integrating factors. Firstly, the generalized Pfaff-Birkhoff principle and the generalized Birkhoff equations are established, and the definition of the integrating factors for the system is given. Secondly, based on the concept of integrating factors, the conservation theorems and their inverse for the generalized Birkhoff system in the event space are presented in detail, and the relation between the conservation laws and the integrating factors of the system is obtained and the generalized Killing equations for the determination of the integrating factors are given. Finally, an example is given to illustrate the application of the results.

Study on the Calibration Function of Local Earthquake Magnitude in the Gansu Region

To calculate the deviations between single station magnitudes and average ones by the magnitude residual statistical method,the paper selects 13086 seismic events recorded by the Gansu broadband digital seismic network from January 2009 to December 2012. The frequency distribution and quantitative statistics of the deviations of earthquake magnitude are analyzed. The MLcalibration function is modified and a uniform local magnitude system characteristic of the Gansu region,is obtained.

Handling epistemic uncertainties in PRA using evidential networks

In order to overcome the limitations of traditional methods in uncertainty analysis, a modified Bayesian network(BN), which is called evidence network(EN), was proposed with evidence theory to handle epistemic uncertainty in probabilistic risk assessment(PRA). Fault trees(FTs) and event trees(ETs) were transformed into an EN which is used as a uniform framework to represent accident scenarios. Epistemic uncertainties of basic events in PRA were presented in evidence theory form and propagated through the network. A case study of a highway tunnel risk analysis was discussed to demonstrate the proposed approach. Frequencies of end states are obtained and expressed by belief and plausibility measures. The proposed approach addresses the uncertainties in experts' knowledge and can be easily applied to uncertainty analysis of FTs/ETs that have dependent events.

A Concurrent Security Monitoring Method for Virtualization Environments

Recently,virtualization technologies have been widely used in industry.In order to monitor the security of target systems in virtualization environments,conventional methods usually put the security monitoring mechanism into the normal functionality of the target systems.However,these methods are either prone to be tempered by attackers or introduce considerable performance overhead for target systems.To address these problems,in this paper,we present a concurrent security monitoring method which decouples traditional serial mechanisms,including security event collector and analyzer,into two concurrent components.On one hand,we utilize the SIM framework to deploy the event collector into the target virtual machine.On the other hand,we combine the virtualization technology and multi-core technology to put the event analyzer into a trusted execution environment.To address the synchronization problem between these two concurrent components,we make use of Lamport's ring buffer algorithm.Based on the Xen hypervisor,we have implemented a prototype system named COMO.The experimental results show that COMO can monitor the security of the target virtual machine concurrently within a little performance overhead.

Critical Contingencies Ranking for Dynamic Security Assessment Using Neural Networks

A number of contingencies simulated during dynamic security assessment do not generate unacceptable values of power system state variables, due to their small influence on system operation. Their exclusion from the set of contingencies to be simulated in the security assessment would achieve a significant reduction in computation time. This paper defines a critical contingencies selection method for on-line dynamic security assessment. The selection method results from an off-line dynamical analysis, which covers typical scenarios and also covers various related aspects like frequency, voltage, and angle analyses among others. Indexes measured over these typical scenarios are used to train neural networks, capable of performing on-line estimation of a critical contingencies list according to the system state.

On the Rebuilding of Cultural Identity and Orthodoxy： A Brief Socio-historical Analysis of China＇s Social Transformation since the Ming and Qing

The socio-historical analysis of ＂Chinese Modernity＂ and ＂Chinese Cultural Identity＂ within the context of social transformation, by restoring the origin of modernity as a ＂historical event＂ since late Qing, leads to the finding that ＂the Deng Zheng-lai Problem＂ pinpoints the current crisis of cultural identity and the loss of Orthodoxy（daotong） which infects contemporary China. It is necessary to build and shape the mode of cultural identity in response to the pressure of rightness, creating ＂the identity of hybridity＂ by negotiating the classic tradition with the socialist tradition and a partial western tradition. By observing ＂the Deng- Hui frameworks＂ （the frameworks formulated by Deng Zheng-lai, Wang Hui, Deng Xiao-mang and Qin Hui）, we should neither blindly return to the classic tradition nor uncritically resort to the Western resources in our attempt at rebuilding cultural identity; instead, one mode of a ＂New Civilization＂ might arise in the sense of what Liang Qi-chao regards as cutting across both China and the West.

OBSERVABILITY OF EXTENDED TIMED EVENT GRAPH

In this paper, we study some results of extended timed event graph (ETEG)by using graph theory's methods in the dioid framework. A necessary and sufficient con-dition for the observability of ETEG is obtained and ETEG's standard structure is alsoestablished.