电子政务身份认证技术解决方案(一)

本文对党政办公网络身份进行了系统的分析,解决了身份认证系统的各种应用环境的身份认证的安全问题,最后把各种系统强化的认证体系的用户身份统一到同用户身份同一的介质上,建立了跨系统和业务统一的身份认证和访问控制系统.既强化了各种应用的安全,又使各级领导使用方便,不失为政府办公网络理想的安全身份认证体系.     

网络安全“动静”结合

中国网通 i-DXnet——网络型 IDC 推出了新一代高可靠性网络安全系统,该系统将“静态”和“动态”安全技术进行了有机的结合,将为用户提供全方位的网络数据和系统方面的安全服务。此安全系统的最大特点在于能够在进行静态网络防护的同时,通过专用网络安全检测工具去主动检测网络系统中的易受攻击点和安全漏洞,并能够先于人工探测到各种“危险的行为”,从而将各种安全隐患和安全问题拒于数据中心之外,保     

电子政务身份认证技术解决方案(一)

本文对党政办公网络身份进行了系统的分析,解决了身份认证系统的各种应用环境的身份认证的安全问题,最后把各种系统强化的认证体系的用户身份统一到同用户身份同一的介质上,建立了跨系统和业务统一的身份认证和访问控制系统.既强化了各种应用的安全,又使各级领导使用方便,不失为政府办公网络理想的安全身份认证体系.     

日志管理要过三道"槛"

随着网络规模的不断扩大和网络结构的日益复杂,各种网络设备、安全设备及应用系统等数量的激增,使各种问题出现得越来越频繁。这些问题出在哪?如何才能避免类似事件的发生?     

TD-SCDMA系统业务QoS仿真分析

Qos问题是第三代移动通信系统的一个重要技术问题.本文主要研究TD-SCDMA系统的QoS问题.利用OPNET Modeler软件,根据无线接入网络的协议构建网络仿真模型,参照3GPP技术规范定义的业务要求,对各种业务的QoS性能和指标进行了比较和分析.     

网络信息安全浅析

本文分析了我国信息安全问题不容乐观的现状和网络管理系统存在的安全威胁,并提出了各种防范措施解决以上问题,从而对网络管理系统加以保护。     

网络监控平台的应用研究

信息化发展到今天,网络架构已日益成熟,随着网络应用逐渐普及,各种网络问题也随之出现,网络遭受黑客攻击、病毒破坏、误操作等都会影响到网络的正常运转。网络监控系统为提高网络管理水平,保证网络发挥最大作用提供了必经之路。网管系统的设计要重点解决两个主要技术问题:监控数据信息获取和传输模式与监控结果的可视化显示,现将前者加以详细说明。     

ControlNet网络在海上油气田开发中的应用

从技术应用背景分析ControlNet网络出现的时代背景及工业领域对该网络的需求状况,全面分析了ControkNet网络概况和系统原理,介绍了构建ControlNet网络的各种设备性能。本文结合工作中工程实例介绍了ControlNet网络的具体应用,探讨了ControlNet网络解决实际工程问题的可行性。     

浅谈网络报销系统

随着财务精细化管理的推进,财务报销信息化越来越被重视。以某企业实际需求为例,通过分析该企业当前报销模式的缺陷和由此产生的各种问题,提出了网络报销系统对这些问题的解决方式。对网络报销系统与帐务系统的集成模式进行了探讨,并针对每种集成模式导致的报销流程的变化进行了详细的分析。对企业开发或外购网络报销系统有参考意义。     

网络考试系统的研制

分析了传统考试中的各种不便，提出了计算机网络考试系统的设计、实施方案，解决了编程和使用中的许多问题，指出了系统的特点。     

机器人足球比赛截球策略设计

在机器人世界杯足球锦标赛(TheRobotWorldCup,简称RoboCup)中,截球效率直接影响到比赛的结果。通过足球截球模型,建立方程,从而求出截球位置。解方程的根是提高截球效率的关键,本文采用高效的弦割法来快速计算方程的根。试验发现方程曲线的变化对弦割法解方程根的效率有很大影响,曲线的形状直接影响了弦割法的收敛速度。为加速收敛性,对弦割法进行了优化。最后与优化前的弦割法以及二分法进行了比较,结果表明优化后整体性更为高效,很好地满足了比赛的要求。     

Analytic Controlling Reorientation of a Spacecraft Using a Combined Criterion of Optimality

We consider the problem of optimally controlling the reorientation of a spacecraft (SC) from an arbitrary initial angular state into a given final angular position. We study the case when the minimized functional joins, in the given proportion, the time spent and the integral of the squared modulus of the angular momentum on the reorientation of a SC. The problem is solved in a kinematic setting. We consider two versions of the problem of the optimal rotation of a SC, with bounded and unbounded control. Using the necessary optimality conditions in the form of the Pontryagin maximum principle and the quaternion method for solving control problems on the motion of spacecrafts, we obtain an analytical solution of the posed problem. The solution of the problem is based on the quaternionic differential equation relating the angular momentum vector of a SC with the orientation quaternion of the related coordinate system. We present formalized equations and give computational expressions for constructing the optimal control program. We state the control law as an explicit dependence of the control variables on the phase coordinates. Using the transversality condition as a necessary optimality condition, we determine the maximal value of the modulus of the angular momentum for the optimal motion. For a dynamically symmetric SC, the problem of reorientation in space is solved completely: we obtain the dependences for the optimal law of the change of the angular momentum vector as explicit time functions. We give the results of the mathematical modeling of the motion for optimal control which demonstrate the practical realizability of designed algorithm for controlling the spatial orientation of a SC.     

Application of a global model to the study of Arctic basin pollution: radionuclides,heavy metals and oil hydrocarbons

The status of pollution of the Arctic basin is studied in ecological terms, and the interactions of the Arctic ecosystem with the global system are estimated. A spatial simulation model for the kinetics of pollutants in the Arctic basin is proposed in which the ecological and spatial distribution of the hydrological parameters is taken into account. The model includes blocks describing the flows of pollutants in the trophic chains, the exchange between the water–ice system and the atmosphere and the interaction of the water ecosystem with the global biosphere–climate system. A global model controls the inputs of the simulation model and makes it possible to compute the dynamics of the distribution of pollutants between the Arctic aquatories, which include the Central basin and the peripheral seas. The model uses both published data and the data of the US/Russian expedition to Siberia accomplished in the summer of 1995. Climatic and anthropogenic processes are described in the form of scenarios. The results of computer experiments are given demonstrating the advantages of the simulation model to forecast and to estimate the dynamics of radionuclides, heavy metals and oil hydrocarbons in the Arctic Seas. The total and local pictures of the spatial distribution of pollutants in the Arctic basin are given as functions of various environmental and anthropogenic parameters. It is concluded that the use of the global biospheric model enables the consideration of the interactions between the Arctic basin environment and adjoining territories. This allows estimates to be made of the consequences of the anthropogenic impact on the Arctic ecosystem.     

OWA aggregation of intuitionistic fuzzy sets

We recall the concept of an intuitionistic fuzzy subset (IFS). Fundamental to an IFS is the fact that it is defined using two values, a degree of membership and degree of non-membership. The ordered weighted averaging (OWA) operator is introduced and several of its features are described. Particularly notable is the idea of the dual of an OWA operator. We next discuss the aggregation of a collection of IFS using a prescribed OWA operator. It is shown that while the aggregation of the degrees of membership is performed using the prescribed OWA operator, the aggregation of the degrees of non-membership requires use of the dual of the prescribed OWA operator. The Choquet integral aggregation operator is introduced and applied to the aggregation of IFSs. Here again the concept of the dual is needed to perform the aggregation of the degrees of non-membership. We also discuss the aggregation of IFSs using the Sugeno integral. Fundamental to this work is our realisation of the importance of the concept of the dual operators in dealing with the aggregation of IFS.     

Calculation of the parameters of Hidden Markov models used in the navigation systems of surface transportation for map matching: A review

This article provides an overview of the mathematical methods for calculating the parameters of Hidden Markov Models (HMM) used in conjunction with the map coordinates measured by the global positioning systems (GPSs) of mobile navigation systems. These methods are analyzed and compared. There is considered an example of calculating of emission probability of observations emissions and transition probabilities for the Hidden Markov Model of a road network. The example is accompanied by the construction of a states diagram of the HMM and a trellis diagram of the Viterbi algorithm. Using the example, there is estimated the influence of the choice of the value of the standard deviation for the probability density distribution of the minimum distances and the angles difference between the direction of the road element and the direction of the velocity of the vehicle on the probability of the path on the Viterbi trellis. It is proposed to use the functional dependence of the optimal path on the standard deviations and the orthogonal distances for the correction in the process of testing and the practical application of the algorithm of map matching based on the HMM.     

A model of the functional state of participants of laboratory markets

The dynamics of psycho-physiological characteristics of participants of laboratory markets in the process of making economical decisions in the decentralized control system is analyzed. For this purpose, the method based on the comparison of stabilographic data with the history of market actions recorded in the course of the experiment is used. The key tool for data analysis is the new segmentation algorithm, which provides efficient partitioning of the stabilographic time series into homogeneous fragments. The segmentation algorithm is obtained as the solution of the problem of estimation of the parameters of the hidden Markov model. The application of this algorithm on the level of individual decision making proves the hypothesis of connection of the stabilogram segmentation time instants of the participant with the time instants of signal actions on the laboratory market. On the level of group decisions, the effect of synchronization of stabilographic time series of participants at the time instant of auction culmination connected with revelation of private information is supported. The degree of synchronization is estimated using a proximity factor calculated based on the specially aggregated canonical correlation.     

A method of defuzzification based on the approach of areas' ratio

The new method of defuzzification of output parameters from the base of fuzzy rules for a Mamdani fuzzy controller is given in the paper. The peculiarity of the method is the usage of the universal equation for the area computation of the geometric shapes. During the realization of fuzzy inference linguistic terms, the structure changes from the triangular into a trapezoidal shape. That is why the universal equation is used. The method is limited and can be used only for the triangular and trapezoidal membership functions. Gaussian functions can also be used while modifying the proposed method. Traditional defuzzification models such as Middle of Maxima − MoM, First of Maxima − FoM, Last of Maxima − LoM, First of Suppport − FoS, Last of Support − LoS, Middle of Support − MoS, Center of Sums − CoS, Model of Height − MoH have a number of systematic errors: curse of dimensionality, partition of unity condition and absence of additivity. The above-mentioned methods can be seen as Center of Gravity − CoG, which has the same errors. These errors lead to the fact that accuracy of fuzzy systems decreases, because during the training root mean square error increases. One of the reasons that provokes the errors is that some of the activated fuzzy rules are excluded from the fuzzy inference. It is also possible to increase the accuracy of the fuzzy system through properties of continuity. The proposed method guarantees fulfilling of the property of continuity, as the intersection point of the adjustment linguistic terms equals 0.5 when a parametrized membership function is used. The causes of errors and a way to delete them are reviewed in the paper. The proposed method excludes errors which are inherent to the traditional and non- traditional models of defuzzification. Comparative analysis of the proposed method of defuzzification with traditional and non-traditional models shows its effectiveness.     

Design of characteristics of air-pressure-controlled hydraulic shock absorbers in an intercity bus

The air-pressure-controlled shock absorber is capable of changing its damping force depending on the air pressure in the air springs. Due to the possibility of improving dynamic properties of all vehicles that use the axles’ air suspensions, BRANO Inc. (the Czech producer of shock absorbers) started to develop semi-active air-pressure-controlled hydraulic telescopic shock absorbers. The SOR C 12 intercity bus is the reference vehicle for which the research and development of controlled shock absorbers is done and on which the shock absorbers are verified. Force–velocity characteristics of the controlled shock absorbers of the axles’ air suspension were designed on the basis of results of computer simulations with the bus multibody models created in the alaska simulation tool. Multibody models of an empty vehicle, a fully loaded vehicle and three variants of a partly loaded vehicle were created. For each weight of the bus two multibody models of various levels of complexity were created. Since the bus multibody models should be used especially for designing force–velocity characteristics of air-pressure-controlled shock absorbers, great attention (in the framework of the possibilities of multibody dynamics) was paid to the correct interpretation of the real behaviour of hydraulic shock absorbers and air springs of the axles’ suspension. As a criterion for the design of the optimum force–velocity characteristics of the controlled shock absorbers, the maximum similarity of the dynamic responses of multibody models of the bus of all the considered weights to dynamic response of the reference multibody model of the bus with the same load as during the experimental measurements on the real vehicle (approx. 71.5% of the maximum loaded vehicle weight) was chosen. In the course of the measurements the non-controlled shock absorbers’ characteristics were optimally tuned for that vehicle weight. Time histories of relative deflections of the axles’ air springs determined during the simulations of the vehicle running over the vertical artificial obstacle were compared. The approach based on the evaluation of the correlation coefficient of two time series was used for the evaluation of the dynamic responses accordance.     

人工免疫在未知木马检测中的应用研究*

针对传统木马检测技术比较被动这一缺陷,提出一种基于人工免疫原理的木马检测方法。利用人工免疫具有自适应以及免疫学习能力的特点,将人工免疫原理应用到木马检测中。分析了数据来源特征,给出了计算抗体与抗原或抗体与抗体之间相似度以及抗体的适应度公式,建立了一个木马检测系统模型;实验测试了利用人工免疫的方式检测木马能有效提高木马检测的检测率,减少误报率。     

Choice of optimal strategy of tumor chemotherapy in Gompertz model

A mathematical model of tumor growth dynamics based on the Gompertz model is considered. It is assumed that tumor cells are affected by a chemotherapeutical agent capable of killing these cells. The degree of action is characterized by the therapy function. Two types of therapy functions are studied: the monotonic and the threshold ones. In the first case, the action of the chemotherapeutical agent is the larger, the higher its concentration. In the second case, the degree of action decreases if the concentration exceeds some threshold value. It is assumed that the concentration of the chemotherapeutical agent is controlled using the control function; the maximum value of this function is limited. The problem of synthesis of optimal control for minimization of the number of tumor cells at the end of the process is formulated. The problem is solved using the dynamic programming method. Exact solutions to the corresponding Hamilton-Jacoby-Bellman equations, which make the synthesis of optimal control possible, are obtained. The results of calculations for optimal therapy strategies are presented.