Conversion of units of measurement

Algorithms are presented for converting units of measurement from a given form to a desired form. The algorithms are fast, are able to convert any combination of units to any equivalent combination, and perform dimensional analysis to ensure that the conversion is legitimate. Algorithms are also presented for simplification of symbolic combinations of units. Application of these techniques to perform automatic unit conversion and unit checking in a programming language is described     

多总线的采煤机齿轮箱试验台监控系统设计

针对采煤机齿轮箱试验台的分布和数据传输的要求,设计了一种多总线的采煤机齿轮箱试验台监控系统,详细介绍了该系统的拓扑结构和通信的实现。基于各种通信协议的特点,该系统采用Modbus,Profibus-DP,TCP/IP总线方式实时采集现场数据并传输到主控制器,实现了数据的远程监控;基于组态软件WinCC开发出系统的通信状态监测界面,实现了通信状态的实时在线监测,方便工作人员及时了解整个系统的通信状态。     

某矿区防雷改造措施分析

针对某矿区220kV线路根据雷电分布图采取的差异性防雷措施效果不理想的问题,分析了风速对线路绕击性能的影响;并结合风速风向和雷电分布图,对该矿区采取以下防雷改造措施:在与风向垂直的线路区的背风侧安装线路避雷器防绕击;对属于危险区域且线路与季风垂直的区域,采用防低接地电阻和安装线路避雷器防反击和绕击;对属于危险区域但受季风影响不是很大的区域,降低杆塔接地电阻防反击。实际运行效果表明,采取防雷改造措施后该矿区线路取得了较好的防雷效果。     

Complexity of families of learning algorithms and estimation of the nonrandomness of extraction of empirical regularities

The paper presents a general approach to the evaluation of the complexity of classes of algorithms, so-called pVCD-method. To develop this method, all the examined families of models of empiric generalization were restricted to classes implementable on computers and, wider, by examining their partially recursive representations. Within the framework of the algorithmic approach, the concept of Kolmogorov’ complexity of algorithms for the recognition of properties or the extraction of regularities is proposed. The method proposed to evaluate the nonrandomness of the extraction of empirical regularities is based on this concept.     

服务业专业化集聚与服务业内部结构演进

服务业结构升级是当下中国经济面临的主要问题之一。本文试图从服务业专业化集聚的角度提供新的动力解释,研究发现服务业专业化集聚对服务业内部结构演进有正的显著的影响,它推动着服务业内部结构的升级和转型。本文先构建一个非均衡的增长模型分析服务业专业化集聚如何影响资源在各个部门间的流动,接着采用省际面板数据分析两者间的关系,最后,针对地区间指标显著的差异,采用分位数回归方法来进一步验证,结果表明,服务业专业化集聚对服务业内部结构演进有着正的影响的结论稳健可靠。     

Automaton Modeling of Processes of Formation and Splitting of Collectives

The problem of determination of the conditions of formation and splitting of a collective (a team) and the problem of determination of the response of a dynamic automaton to specified input processes are shown to be equivalent. Based on this fact, an automaton model of a collective is constructed. The apparatus of continuous logic and logical determinants are used to analyze the model.     

Characterization of robust stability of a class of interconnected systems

We consider robust stability analysis of a class of large scale interconnected systems. The individual subsystems may be different but they are assumed to share a property that characterizes a set of interconnection matrices which lead to stable overall systems. The main contribution of the paper is to show that, for the case where the network interconnection matrix is normal, (robust) stability verification can be simplified to a low complexity problem of checking whether the frequency response of the individual subsystems and the eigenvalues of the interconnection matrix can be mutually separated using a class of quadratic forms. Most interestingly, it is shown that this criterion is also necessary, in the sense that if the criterion is violated, an interconnection matrix of the same eigenvalue distribution can be found to make the overall system unstable.     

论网络中心战理论对我军军事斗争准备的启示

网络中心战是新军事变革的产物,是信息技术与军事装备相结合的产物。它是通过扁平化的网络,把信息优势转变为作战行动优势,最终实现"发现即摧毁"的作战目标。网络中心战理论自产生以来就受到广泛关注,并在阿富汗、伊拉克战争中得到了实战检验,达到了预期效果。网络中心战从理论到实践的发展历程表明:信息优势是夺取战争胜利的重要前提,要始终注意各类信息资源的开发利用;先进的军事技术是夺取战争胜利的物质基础,要加速武器装备的信息化改造与升级;高素质的人才是依然是夺取战争胜利的决定性因素,要充分发挥人的主观能力性。     

物联网感知层局域按需簇维护模型与算法

基于无线传感网的物联网感知层传统的“全网”、“周期性”重新成簇的簇维护模式因超范围过度维护,存在维护成本高、能量浪费严重、服务全面中断、响应不及时等缺点.局域按需簇维护方法(local and on-demand maintenance of clusters,简称LDMC)将簇维护操作控制在簇受损的时间和空间范围内,通过设置触发源、预处理和维护动作分别解决簇维护启动、簇维护方式和簇维护范围问题,不仅能够克服簇更新周期确定的困难,而且可在节点失效和新节点加入时对网络拓扑和路由变化及时进行响应,减小突发事件对网络功能的影响,改善网络的稳定性并降低其维护开销.基于NS2仿真平台,分别从能量消耗、数据传输、负载平衡和突发事件响应等角度对该方法进行了测试对比,仿真结果表明,该方法能够明显减少簇维护的能量消耗、延长网络生存时间,并增加传输数据包的 总量.     

中小企业计算机网络的构建

该文针对如何构建中小企业网络的问题,给出了一个方法,还就如何解决网络过程中的设备选型,网络速度,防毒防黑等问题,给出了一些自己的想法。     

面向工科学生创新能力培养的实验室开放体系建设

构建科学合理的实验室开放体系,对于培养工科大学生的创新精神和实践能力至关重要。从如何开放实验内容、将学生吸引到实验室、采取何种方式激励教师投入等角度,对实验室开放体系的建设进行探讨。     

A study of the effect of different types of noise on the precision of supervised learning techniques

Machine learning techniques often have to deal with noisy data, which may affect the accuracy of the resulting data models. Therefore, effectively dealing with noise is a key aspect in supervised learning to obtain reliable models from data. Although several authors have studied the effect of noise for some particular learners, comparisons of its effect among different learners are lacking. In this paper, we address this issue by systematically comparing how different degrees of noise affect four supervised learners that belong to different paradigms. Specifically, we consider the Naïve Bayes probabilistic classifier, the C4.5 decision tree, the IBk instance-based learner and the SMO support vector machine. We have selected four methods which enable us to contrast different learning paradigms, and which are considered to be four of the top ten algorithms in data mining (Yu et al. 2007). We test them on a collection of data sets that are perturbed with noise in the input attributes and noise in the output class. As an initial hypothesis, we assign the techniques to two groups, NB with C4.5 and IBk with SMO, based on their proposed sensitivity to noise, the first group being the least sensitive. The analysis enables us to extract key observations about the effect of different types and degrees of noise on these learning techniques. In general, we find that Naïve Bayes appears as the most robust algorithm, and SMO the least, relative to the other two techniques. However, we find that the underlying empirical behavior of the techniques is more complex, and varies depending on the noise type and the specific data set being processed. In general, noise in the training data set is found to give the most difficulty to the learners.     

Sliding Planning of Development of Macroeconomic System

Consideration was given to (i) planning development of a macroeconomic system and (ii) stimulating producers to follow the plans. Sliding mode of planning was shown to be advisable owing to the fundamental features of planning. The required stimulation can be carried out using the proposed method of taxation.     

Shared domains of competence of approximate learning models using measures of separability of classes

In this work we jointly analyze the performance of three classic Artificial Neural Network models and one Support Vector Machine with respect to a series of data complexity measures known as measures of separability of classes. In particular, we consider a Radial Basis Function Network, a Multi-Layer Perceptron, a Learning Vector Quantization, while the Sequential Minimal Optimization method is used to model the Support Vector Machine.We consider five measures of separability of classes over a wide range of data sets built from real data which have proved to be very discriminative when analyzing the performance of classifiers. We find that two of them allow us to extract common behavior patterns for the four learning methods due to their related nature. We obtain rules using these two metrics that describe both good or bad performance of the Artificial Neural Networks and the Support Vector Machine.With the obtained rules, we characterize the performance of the methods from the data set complexity metrics and therefore their common domains of competence are established. Using these domains of competence the shared good and bad capabilities of these four models can be used to know if the approximative models will perform well or poorly or if a more complex configuration of the model is needed for a given problem in advance.     

《数据结构》上机作业难完成的成因分析

通过对保山学院计科系2005~2010届的学生难以完成《数据结构》上机作业的情况分析，从教学方法的角度寻找原因，根据实际情况提出上机实训教学改革的具体措施，以促使学生顺利完成作业，提高用计算机解决问题的能力。     

《数据结构》上机作业难完成的成因分析

通过对保山学院计科系2005~2010届的学生难以完成《数据结构》上机作业的情况分析,从教学方法的角度寻找原因,根据实际情况提出上机实训教学改革的具体措施,以促使学生顺利完成作业,提高用计算机解决问题的能力。     

时态类型集的封闭集

好的数据库逻辑设计目标是消除数据冗余以及插入和删除异常。对于时态数据库，可以利用具有多时间粒度的时态函数依赖（TFDs）约束对时态数据库进行规范化。要进行有效的数据库设计，需要解决有限属性闭包和成员籍等一些有关TFD的问题。为了方便计算机对时态类型的处理和找到有效的解决TFD的相关问题的算法，该文提出了封闭时态类型集的概念，并且给出了一个求给定TFD集的封闭集的算法。     

Linux进程管理体系的研究与分析

Using an opened source system, Linux, as the supported OS is more and more appealing to many developers. So it is attractive to many developers to understand the designing philosophy of Linux and more importantly, improve its performance to satisfy the specific requirements. This paper analyzes process management of Linux ,and the schedule algorithm of Linux is alsopresented.     

Translation separability of sets of polygons

We consider the problem of separating a set of polygons by a sequence of translations (one such collision-free translation motion for each polygon). If all translations are performed in a common direction the separability problem so obtained has been referred to as the uni-directional separability problem; for different translation directions, the more general multi-directional separability problem arises. The class of such separability problems has been studied previously and arises e.g. in computer graphics and robotics. Existing solutions to the uni-directional problem typically assume the objects to have a certain predetermined shape (e.g., rectangular or convex objects), or to have a direction of separation already available. Here we show how to compute all directions of unidirectional separability for sets of arbitrary simple polygons.The problem of determining whether a set of polygons is multi-directionally separable had been posed by G.T. Toussaint. Here we present an algorithm for solving this problem which, in addition to detecting whether or not the given set is multidirectionally separable, also provides an ordering in which to separate the polygons. In case that the entire set is not multi-directionally separable, the algorithm will find the largest separable subset.Research supported by NSERC under grant No. A9173 and A0392, respectively     

An analysis of the use of virtual delivery of undergraduate lectures

Educators and technologists have been wrestling with the most appropriate way in which to use information technology in teaching and in learning, for some years. We have seen online course notes, both linear, hypertext and hypermedia format, lecturer/student communication via electronic bulletin boards or via e-mail, multimedia courseware with student-directed learning and many others. All of these approaches have had limited impact on mainstream teaching in our universities and colleges and we believe one of the reasons for this is that these attempts all represent a significant shift in the normal student–lecturer relationship and an enormous amount of effort on the part of the lecturer. In our work we have addressed this by using technology to replicate the traditional mode of delivery of lectures to a class. The presentation of lecture material was digitally recorded, both audio and synchronised visuals, and made available for students to take in their own time. In addition we provided 3 orthogonal means to access this material. The present paper describes our analysis of the use of these `virtual lectures' by a class of over 100 students. Our analysis includes log files of all accesses to the online material, pre-course and post-course questionnaires and anonymous questionnaire feedback, some of this is compared to exam performance. Results indicate that mode of delivery, student usage and a student's technical bias have no impact on overall exam performance.