基于安全隔离的边界防护体系的设计与实现

本文针对电子政务信息系统的特点,设计了基于安全隔离的边界防护体系。将安全隔离技术应用到电子政务中,实现了数据的安全高效实时传输,形成了多方位的安全边界防护体系架构。     

计算机网络的安全防范技术分析

近年来,随着我国科学技术的日益发展进步,计算机的应用越来越普及,在人们日常生活和工作中发挥着重要作用,影响着人们的生活质量和社会的发展。而且计算机的使用人群很广泛,不论是教师、公务员、医生或者农民、工人等等,都在逐渐接触它,无疑将是人类生存的重要助手。但正是如此,在使用计算机的过程中暴露了许许多多的问题,给人类带来了伤害,我们应该主动去防范,本文正是对此进行研究。     

用于局域网的网络嗅探器的设计

目前,世界上主流的嗅探器都是以捕获数据包为其核心技术,而对于抓包过程有两种常见的机制,第一种是常见的UNIX／LINUX内核本身所具有的抓包功能。第二种是使用第三方软件和抓包驱动来实现抓包功能。本文根据网络嗅探的技术、原理、方法做出详细的论述,同时,讨论了现在使用较为广泛的嗅探软件与技术,然后,通过进行软件功能需求分析,我们论述了一个嗅探技术的新思路,用它来帮助网络管理人员对局域网进行监控。     

A comparison of some approaches to classification problems,and possibilities to construct optimal solutions efficiently

We consider sequential linear (binary) classifiers for the case of many classes along with the linear classifiers based on determining the maximum discriminant function. It is shown that the capabilities of sequential binary classifiers are wider than those of linear classifiers. For the case of linearly non-separable training samples there are considered approaches based on minimizing the margin of misclassification and minimizing empirical risk. It is shown that problem of minimizing the margin of misclassification is polynomially solvable for a certain choice of the norm in the feature space. A refined model of the empirical risk minimization problem and its continuous relaxation are considered, a comparison with the mathematical model of SVM is done. The results of numerical experiments comparing different approaches are discussed.     

Fast Simulation of the Functional Failure of an s – t-Network with Repair

An s – t-network with highly reliable edges with repair and variable external load is considered. A fast simulation method is proposed to evaluate the probability of functional failure when the real capacity of the network is less than the required capacity. It is proved that under some conditions the estimate has a bounded relative error as edges reliability increases. The numerical example illustrates the efficiency of the method.     

Optical elements for focusing of terahertz laser radiation in a given two-dimensional domain

Binary silicon-based diffractive optical element (DOE)—Gaussian-to-Square focuser (diameter of aperture is 30 mm) for the terahertz spectral range has been designed and characterized using terahertz radiation of the Novosibirsk Free Electron Laser (NovoFEL) at the wavelength of 141 μm. The preliminary experiments have demonstrated feasibility of application of binary silicon DOE for focusing of terahertz radiation into pre-given focal domain.     

基于Web网的高校安全管理系统的设计与开发

为了解决高校安全保卫工作办公方式落后、管理水平低下等问题,开发了一套基于Web网的高校安全管理系统。介绍了系统设计和架构框图,并对系统功能做了进一步的实现,最后展示了运行效果。     

浅谈计算机管理信息系统的发展及其经济效益

在社会各行各业竞争日趋激烈的形势下,有效、科学的管理是企业生存的必备条件.其中以信息管理为重要手段,数据的收集处理的快速准确化,为企业降低成本,带来更好的经济收益,也使得企业在生产过程中对组织内部进行更合理有效的调整,对组织外部的各类企业有更好的交流,而本身的重大决策,也有了更加科学的依据.本文介绍了信息系统的发展,以及如何带来经济收益.     

管窥立体电影反应技术发展

随着电影行业的不断发展,数字3D立体电影的应用日益广泛。本文从立体电影的原理出发,在对传统立体电影的应用技术进行了阐述后,着重分析了现今电影行业应用最为广泛的几种数字3D电影应用技术,集中探讨了不同放映技术的工作原理及其优缺点。最后就数字3D技术的发展前景进行了探讨,为数字3D电影的长远发展提供理论支持。     

On wind turbine blade design optimization

A wind turbine with a horizontal rotation axis is considered in the stationary airflow. A problem of choosing the law of change of the setting angle of the cross section of the wind turbine blade and the value of the angular speed so that the wind energy utilization coefficient is maximal is discussed. Maximization of the respective functional is considered as a variational problem with a priori unknown parameter. Once it is solved numerically or analytically, the optimal value of this parameter is determined, with the sought variables given by rather simple formulas. The results are analyzed on a qualitative level. In particular, the setting angle is found to change monotonically along the blade, which is confirmed by practical wind turbine design. Examples of using the proposed approach to wind turbine blade design are considered.