IDS、IPS技术研究

首先介绍了IDS、IPS两种网络安全技术的概念，在此基础上分析了两种技术的相同点、不同点，指出了它们的技术缺陷，并提出完善建议。     

Numerical study of internal flow field and flow passage improvement of an inlet particle separator

By performing gas flow field numerical simulations for several inlet Reynolds numbers Re (from 2 × 10⁵ to 9 × 10⁵) and byflow ratios x (from 10% to 20%), the present study has proposed to improve the flow passage of an inlet particle separator. An adjacent objective of the study is to lower pressure losses of the inlet particle separator (IPS). No particle has been included in the gas flow for a k-epsilon turbulence model. The velocity distribution in different sections and the pressure coefficient C_p along the duct have been analyzed, which indicates that there exist important low-velocity regions and vortices in the separation area. Therefore, the profile of streamlines along the original passage has been considered. This profile illustrated a vacuum region in the same area. All investigations suggest that the separation area is the most critical one for fulfilling the objective on pressure losses limitation. Then the flow passage improvement method has focused on the separation area. An improved shape has been designed in order to suit smoothly to the streamlines in this region. Similar numerical studies as those for the original shape have been conducted on this improved shape, confirming some considerable enhancements compared with the original shape. The significant vortices which appear in the original shape reduce in amount and size. Besides, pressure losses are greatly decreased in both outlets (up to 30% for high Reynolds number) and the flow is uniform at the main outlet. Subsequent engineering surveys could rely on expressions obtained for C_p in both outlets which extend the pressure losses for a wide range of inlet Reynolds numbers. As a result, the numerical calculations demonstrate that the flow passage improvement method applied in this study has succeeded in designing a shape which enhances the flow behavior.     

Reliability evaluation for an intermittent production system with stochastic number of normal machines

In an intermittent production system (IPS), a number of normal machines in a workstation may present multiple levels owing to maintenance, possibility of failure, etc. It means that the number of machines in each workstation is stochastic. This paper proposes a key performance index (KPI), which reflects the probability that an IPS can complete demand d within time constraint T. Such a probability is defined as system reliability. The IPS is modeled as a stochastic network, in which each arc is regarded as a workstation with stochastic number of normal machines, and each node is represented as a buffer. The concept of minimal machine vector (MMV), which indicates the minimal capacity required at each workstation to satisfy the demand and time constraints, is presented for evaluating the system reliability. In particular, a novel algorithm based on depth-first search is proposed to derive all MMVs. This algorithm avoids searching for unnecessary child nodes, and thus increases efficiency. Two practical examples, a printed circuit board and a footwear manufacturing systems, are used to illustrate the proposed algorithm. Such a KPI can provide information to production managers to understand the probability that an order can be completed on time.     

基于IPS的DNS协议解析引擎的设计

在对传统的网络安全技术进行研究的基础上,设计和实现了基于IPS的DNS协议解析引擎。阐述了DNS协议解析引擎的总体框架,建立了相关的模型。该引擎采用先进的NEL语言开发平台,实时地检测出异常流量,实现了实时、高性能的网络安全。     

IPS液晶取向膜表面光学各向异性DΔ的研究

针对共面转换IPS(In-Plane-Switching)液晶显示模式取向膜,利用反射椭偏消光法测量了取向膜表面的光学各向异性DΔ值。研究了在不同摩擦条件和亚胺化温度条件下,取向膜表面光学各向异性值DΔ值的变化。研究结果表明,随着亚胺化温度升高,DΔ值呈现下降趋势。在摩擦强度各因子中,压入量和转速对于DΔ值影响较大。DΔ值可作为一种定量化评价取向膜取向状态的方法,并可作为生产过程中对于液晶稳定性取向的管控方法使用。     

Effective allied network security system based on designed scheme with conditional legitimate probability against distributed network attacks and intrusions

Dependence on the Internet is increasing dramatically. Therefore, many researchers have given great attention to the issue of how to tighten Internet security. This study proposes a new scheme for the distributed intrusion prevention system (DIPS), in which the concept of ‘union’ is presented for satisfying the increasing requirements of Internet security issues. In this proposed design, the network intrusion detection system (NIDS) applies a misuse detection technique to detect well‐known intrusion behavior on the Internet. Meanwhile, for anomaly detection technique, a tool named ‘Scent’ (a network traffic sniffer) is combined with conditional legitimate probability to reveal previously undiscovered intrusion packets that do not match the intrusion signatures in NIDS. Moreover, blocking distributed denial‐of‐service (DDoS) attacks inside the protected allied network is also covered. To increase the detection accuracy, reduction of false positives and false negatives is also accomplished. Experimental results reveal that the suggested network security system scheme is effective and efficient in resolving the intrusion activity problem of real network environments. Copyright © 2011 John Wiley & Sons, Ltd.     

共面转换型42英寸液晶电视的发展

我们通过使用超级共面转换(SuperIn-Plane-Switching)模式和过驱动(Over-Driving)电路技术,开发出具有宽视角和快速响应的42英寸(1280×768,159)大尺寸液晶电视(LCD-TV)。通过使用膜超级共面转换技术获得了在任意方向的宽视角,通过优化液晶材料和液晶盒的设计,获得了更快的响应时间(12ms)。