机车空调逆变电源设计

本文讨论的是机车空调逆变电源系统的设计与研究。该电源系统主要是由DC/DC的BOOST升压部分和DC/AC三相逆变部分两部分组成。DC/DC部分所得直流电压通过DC/AC部分逆变成三相交流电,供给空调机组工作。同时,为使电源系统能更可靠的运行,也设计了相应的故障检测、保护等辅助电路。     

传输线信号完整性的反射分析

针对高速电路系统的传输线信号完整性问题,通过对高速电路PCB上传输线等效电路的分析,给出了信号传输时产生反射现象的原因;介绍了常用的消除反射的方法,即选择均匀传输线、采用合适的拓扑结构布线和阻抗匹配法,指出阻抗匹配法可解决信号传输的反射现象;阐述了源端阻抗匹配法和负载端阻抗匹配法消除反射的原理和适用条件。针对时钟电路中的反射问题,采用PADS/Hyperlynx软件对阻抗匹配法进行仿真,结果表明,阻抗匹配法能够改善信号传输的反射现象。     

Abstraction of levels of abstraction

The notion of level of abstraction (LoA) is one of the foundations of the Floridi's Philosophy of Information. It also serves for many practical purposes as in information ethics. But the notion of abstraction is not new; it has been given many different meanings in various fields, especially in scientific disciplines and, in particular, in computer science. Our purpose here is to examine the use of abstraction in Floridi's works in conjunction with some of the meanings of abstraction in computer science. The article is divided into five sections. After a general introduction to the Floridi's method of abstraction (MoA) in Section 1, Section 2 revisits Floridi's definition of abstraction and Section 3 gives the different senses of abstraction in computer science. The Section 4 compares them with the Floridi's LoAs and proposes to generalise the Floridi's approach to abstraction using an abstraction of the LoAs, while Section 5 concludes on what we think to be some new arguments in favour of MoA and LoA.     

The computation of zones of influence of linear geological structures

The concept of a zone of influence of a linear geological structure provides a method of quantifying the effect of the structure on the properties of its neighborhood. For example, a fault may exert some influence on the local roof conditions in a mine opening, or on the location of mineral deposits, where the influence at any given distance (up to the specified half-width of the zone of influence) from the fault is estimated by some postulated influence function. Any area of interest may be partitioned into a large number of cells, and the sum of the influences due to the nearby faults calculated for the midpoint of each cell. The program groups the cells, by midpoints, into sets comprising those cells affected by precisely 0,1,2,... faults, calculates the proportion each set constitutes of the area of interest, and the total of the midpoint sums of the cells in each set. Although the program was developed for a specific problem in a New South Wales colliery, the method is not specific to this problem and has application to many situations in rock mechanics, metallogenesis, seismicity, and in other fields in which the concept of a zone of influence may be relevant.     

支持向量机多类目标分类器的结构简化研究

由于支持向量机(SVM)在模式识别和回归分析中有着独特优势，因此成为近来研究的热点，其优势主要体现在处理非线性和高维数据问题方面。最初的SVM特别适合解决两类目标分类问题，而对于多类目标分类，则需将其转化为多个两类目标分类问题，相应地即可构造多个两类目标子分类器，但由于这种情况导致了分类器结构的过于复杂，从而导致判决速度的降低。为了快速地进行分类．提出了一种简化结构的多类目标分类器，其不仅使得子分类器数目大大减少，而且使分类速度明显提高；同时对其分类精度和复杂度进行了对比分析。实验结果证明。该分类器是有效的。     

Computational properties of networks of synchronous groups of spiking neurons

We demonstrate a model in which synchronously firing ensembles of neurons are networked to produce computational results. Each ensemble is a group of biological integrate-and-fire spiking neurons, with probabilistic interconnections between groups. An analogy is drawn in which each individual processing unit of an artificial neural network corresponds to a neuronal group in a biological model. The activation value of a unit in the artificial neural network corresponds to the fraction of active neurons, synchronously firing, in a biological neuronal group. Weights of the artificial neural network correspond to the product of the interconnection density between groups, the group size of the presynaptic group, and the postsynaptic potential heights in the synchronous group model. All three of these parameters can modulate connection strengths between neuronal groups in the synchronous group models. We give an example of nonlinear classification (XOR) and a function approximation example in which the capability of the artificial neural network can be captured by a neural network model with biological integrate-and-fire neurons configured as a network of synchronously firing ensembles of such neurons. We point out that the general function approximation capability proven for feedforward artificial neural networks appears to be approximated by networks of neuronal groups that fire in synchrony, where the groups comprise integrate-and-fire neurons. We discuss the advantages of this type of model for biological systems, its possible learning mechanisms, and the associated timing relationships.     

A Comparison of the Bibliometric Indicators of Several Laboratories of a Scientific Institute of the Russian Academy of Sciences

Bibliometric studies using relevant databases are not only in demand in research institutes, universities, and libraries, but are also widely used in the management of science. A model of bibliometric analysis of the publication flow of specific laboratories is considered. Particular attention is paid to the results of the bibliometric analysis, which was carried out taking the developed criteria into account. The important role that is played by libraries in the dissemination of bibliometric data at the request of users is emphasized.     

Synthesis of subminimum-time bounded control of system of rigid bodies

An algorithm of control of a system of rigid bodies in a form of feedback in special coordinates is discussed. The control is bounded, and it is also subminimum-time in the sense that it coincides with the optimal in linear approximation and in the case of a system with one degree of freedom. It is shown that the controller endows the unperturbed motion of the system with the property of asymptotic stability in large and is also robust. The results of numerical experiments, demonstrating the closeness of the trajectories to the time-optimal ones, are presented.     

Modifications of the method of variation of parameters

In spite of being a classical method for solving differential equations, the method of variation of parameters continues having a great interest in theoretical and practical applications, as in astrodynamics. In this paper we analyse this method providing some modifications and generalised theoretical results. Finally, we present an application to the determination of the ephemeris of an artificial satellite, showing the benefits of the method of variation of parameters for this kind of problems.     

Classifying the subjects of the Russian Federation on the basis of analysis of results of Gallup polling

The problem of processing of Gallup poll results by cluster analysis methods is considered. The aim of these polls, performed in different subjects of the Russian Federation, is to extract main characteristics of the regions. Demyanov Egor A. Born 1982. Graduated from the Moscow State University in 2004. Post-graduate student of the same university. Scientific interests: discrete mathematics and mathematical methods of pattern recognition. Author of two publications. Djukova Elena V. Born 1945. Graduated from the Moscow State University in 1967. Received candidate’s degree in Physics and Mathematics in 1979, Doctoral degree in Physics and Mathematics in 1997. Dorodnicyn Computing Center, Russian Academy of Sciences, leading researcher. Moscow State University, lecturer. Moscow Pedagogical University, lecturer. Scientific interests: discrete mathematics and mathematical methods of pattern recognition. Author of 76 papers. Peskov Nikolai V. Born 1978. Graduated from the Moscow State University in 2000. Received candidate’s degree in Physics and Mathematics in 2004. Dorodnicyn Computing Center, Russian Academy of Sciences, junior researcher. Scientific interests: discrete mathematics and mathematical methods of pattern recognition. Author of 17 papers. Inyakin Andrey S. Born 1978. Graduated from the Moscow State University in 2000. Received candidate’s degree in 2006. Dorodnicyn Computing Center, Russian Academy of Sciences, junior researcher. Scientific interests: discrete mathematics and mathematical methods of pattern recognition. Author of 16 papers.     

物联网应用现状及发展机遇

近来,物联网已成为生活中炙手可热的名词,物联网技术的应用已成为推动信息化发展和产业变革的重要力量。物联网技术涉及众多领域,文章介绍了物联网的概念和基本特征,分析了物联网应用的现状,探讨了物联网发展的关键技术,并指出了未来物联网未来的发展机遇,为物联网的发展和建设提供参考。     

The role of internal and external evaluation of properties of methods for the inductive formation of knowledge

The hypothesis is advanced that external evaluation of properties in the inductive formation of knowledge (IFK) method reflects, to greater extent, the degree of separation of object classes in the object domain and, to a lesser extent, the properties of the IFK method itself, while internal evaluation, in contrast, reflects the property of the IFK method and is related, to a lesser degree, to the separability of object classes in the object domain. The experimental confirmation of this hypothesis is presented.     

一种多功能智能拐杖的设计

本次设计的系列老年人专用拐杖,内置GPS定位,红外线语音提示,求助,报警,人性化互动等多项功能,使具有同样爱好的老年人在相遇时拐杖间能产生共鸣,并专为老年人设计符合其手部人机曲线的把手,通过视觉,听觉,触觉等多感官提示,使其不但能助于老年人行走,亦能成为老年人实用贴身的好帮手。     

基于窗口按钮的用户权限管理

比较现有MIS中常见的权限管理解决方法，提出了一种新颖的数据库设计方案，记录用户对其授权菜单对应窗口的权限值，并设计了以窗口中按钮的操作权限为目标，给用户分配权限的系统管理模块，成功地解决了细化到窗口按钮的用户权限管理问题。     

物联网技术在智慧校园建设中的应用

在信息化的时代背景下,信息技术在各行各业中广泛应用,并取得了较好的成效。目前,信息技术在校园生活中广泛渗透,特别是物联网的快速发展为智慧校园的建设提供了重要的技术支持。文章从物联网与智慧校园入手,分析了智慧校园建设中的主要物联网技术,并进一步阐述了物联网技术在智慧校园建设中的应用及发展方向。     

物联网安全综述

随着智能家居、数字医疗、车联网等技术的发展,物联网应用越发普及,其安全问题也受到越来越多研究者的关注.目前,物联网安全的相关研究尚在起步阶段,大部分研究成果还不能完善地解决物联网发展中的安全问题.首先对物联网3层逻辑架构进行了介绍,阐述了每个层次的安全问题与研究现状重点;然后分析并讨论了物联网的主要应用场景(智能家居、智能医疗、车联网、智能电网、工业与公共基础设施)中需要特别关注的隐私保护、入侵检测等安全问题;再次,归纳分析了现有研究工作中的不足与安全问题产生的主要原因,指出物联网安全存在的五大技术挑战：数据共享的隐私保护方法、有限资源的设备安全保护方法、更加有效的入侵检测防御系统与设备测试方法、针对自动化操作的访问控制策略、移动设备的跨域认证方法;最后,通过详尽分析这五大技术挑战,指出了物联网安全未来的研究方向.     

液压支架电液控制系统软件在线升级方案设计

针对现有液压支架间架控制器与端头控制器的软件升级需要技术人员在井下对控制器逐一拆装操作,且耗时长、效率低的问题,提出了一种液压支架电液控制系统软件在线升级方案,详细介绍了液压支架电液控制系统组成、代码存储空间变化及在线升级的相关程序流程,并给出了实验数据及分析。该方案实现了对间架控制器和端头控制器的远程在线升级,升级过程简单方便,且升级速度快。     

手腕骨X线片兴趣区域图像分割的研究

提出了一种准确分割骨骺兴趣区域边缘位置的方法。针对手腕骨X线片图像的特征,采用Gibbs 随机场对兴趣区域进行初始分割,将骨从图像中分割出来;针对骨与软组织的灰度值相差不大,Gibbs 随机场正确分割困难的问题,再进一步利用主动轮廓法对初始轮廓进行改善,将软骨与软组织准确分割开,从而得到了正确的骨的边缘位置。实验验证了该方法对分割出的底部区域骨的轮廓线有较大的改善,同时这种联合的方法具有较强的抗噪声能力。     

电力物联网下无线传感器网络位置隐私保护方法研究

首先对无线传感器网络的概念及其在电力物联网中的应用进行了简单的介绍,指出了无线传感器网络中存在的隐私问题;其次针对位置隐私保护进行了概述,并给出了攻击者模型;接下来,分别介绍了几种源节点位置隐私保护和汇聚节点位置隐私保护技术,并对它们的性能进行了分析和比较;最后,我们对电力物联网中的无线传感器网络位置隐私保护技术所需考虑的问题提出了见解和建议.     

中国古典园林设计中心理学应用分析

对中国传统园林设计中的曲廊、漏窗、堆山、叠石、园林植物配置、园路进行了简要概述,研究中国传统园林中所存在的人的心理、行为活动因素,抓住人的微妙的心理活动,对于现代园林环境的创造起到十分重要的借鉴作用。