有线无线一体化通信系统在煤矿的应用

介绍了矿用行政通信系统、调度通信系统、无线通信系统,提出了煤矿有线无线一体化通信系统解决方案,并介绍了该系统的组成、主要设备及功能特点。应用结果表明,该系统实现了矿井有线无线通信系统的有效融合,达到了统一调度指挥的目的。     

基于云计算技术的地铁自动售检票系统研究

针对地铁线网规模的不断扩大, 原有地铁自动售检票系统出现建设成本高、资源利用率低、后期维护工作困难等问题, 设计了一个基于云计算技术的地铁自动售检票系统（CAFC系统）。构建了系统的整体架构、物理拓扑结构、软件体系结构和云架构, 精简了原有系统的架构、减少了系统容量、降低了系统投资; 分析了系统各层次之间、系统与系统用户之间、系统与外部接口之间的业务逻辑关系; 提出了基于防火墙、入侵检测系统、数据备份和PKI的系统安全解决方案。该系统能够完成地铁自动售检票和票务运营管理等功能, 而且降低了投资成本、提高了资源利用率, 为实现地铁低碳运营、绿色运营提供支持。     

GPS车辆追踪系统的实现

依据珠海１２０系统的实际研制、开发,介绍了ＧＰＳ系统在汽车监控领域的一种应用──车辆自动追踪系统,重点介绍了系统的整体结构、系统原理、系统功能、系统的优点及系统的技术指标。     

神东矿区净水厂自控系统设计

分析了神东矿区净水厂水处理工艺对自控系统的要求,构建了由上位机系统、PLC系统、仪表检测系统、电气控制系统组成的自控系统,并详细介绍了系统硬件构成、上位机软件和PLC软件设计。实际应用表明,该自控系统实现了水处理各工艺阶段的自动控制,保证了水处理系统运行的稳定性和可靠性,具有自动化程度高、操作简单等特点。     

基于多媒体技术的产品协同设计交流系统

该文叙述了协同设计的概念及模式、介绍了CSCW技术,设计开发了一套基于多媒体技术的产品协同设计交流系统,它包含远程网络共享的白板设计系统、协同设计交流室系统、文件传输系统、远程应用程序共享系统及音频、视频系统。     

铁路站场通信系统的研究与设计

对某铁路站场通信系统进行了系统性设计,该系统包括IP软交换系统、VSAT卫星通信系统、视频监控、周界报警系统、安防监控系统、通信电源系统和综合布线系统5个部分,并对6个系统的功能和技术指标进行了分析,为工程设计提供参考.     

室外移动机器人的视觉临场感系统

本文介绍了我们所建立的室外移动机器人的视觉临 场感系统,由摄像机云台系统、头盔系统、通讯系统、视频显示系统组成,集成的系统取得 了令人满意的效果．     

动态电子商务平台的构建

本文提出了一个由网络系统、软件系统、安全系统、产品配送系统、资金结算系统、客户服务系统等六大系统组成的动态电子商务平台网站的整体模型,给出了它的软硬件体系结构,并对系统的有关技术进行了较详细的介绍。     

基于全数字调节的矿井提升机电控系统的改造

针对平煤集团八矿副井提升机采用V-M电控系统存在设备多、噪声高、电控复杂、可靠性低等缺点,文章提出了一种由SCR-D系统代替V-M电控系统的改造方案,介绍了SCR-D系统的结构,分析了主要设备的选型,详细阐述了全数字调节系统的工作原理,并给出了系统的安装与调试。实际运行表明,改造后的提升机电控系统具有保护完善、控制精度高、节能效果好等优点,达到了预期目标。     

巴音郭楞管理局水利信息化系统建设探索

结合巴音郭楞管理局对水利信息化系统的需求,首先介绍了信息化系统的建设背景以及原有系统的局限性;围绕以智慧水利建设推动组织机构调整的总体建设目标阐述了信息化系统的设计思路、总体框架、网络结构,详细介绍了系统的建设内容,包括现地监测监控系统、网络与安全系统、支撑平台系统、一体化管控平台应用系统、智能应用系统;组织机构调整的目标、具体设置、调整时或可存在的问题及对策,以期对类似水利工程的信息化建设提供参考。     

Estimating the Attraction Domain for the Boost Inverter

This work presents an approach for estimating the domain of attraction for polynomial systems with state and control‐signal constraints, including saturation. In many problems, it is possible to derive global stability properties for such systems, neglecting constraints. Consideration of the constraints usually makes the problem much more complicated. In this paper, the stability analysis performed for the unconstrained case is used for the problem as a whole. For application of the method, there are powerful computational tools that can be employed in cases of polynomial systems. The technique is not only valid for the analysis of equilibrium points, but also for other attractors, such as limit cycles. As examples, the domain of attraction for given control laws is estimated for both a nonlinear DC‐DC boost converter and for a boost inverter.     

Meme Media for Clipping and Combining Web Resources

The publication and reuse of intellectual resources using the Web technologies provide no support for us to clip out any portion of Web pages, to combine them together for their local reuse, nor to publish the newly composed object as a new Web page for its reuse by other people. This paper shows how the meme-media architecture is applied to the Web to provide such support for us. This makes the Web work as a shared repository not only for publishing intellectual resources, but also for their collaborative reediting. We will propose a general framework for clipping arbitrary Web contents as live objects, for defining IO ports on such a clip, and for the recombination and linkage of such clips based on both the original and some user-defined relationships among them. In our previous works, we proposed two separate frameworks for these three purposes; one works for the first two, and the other for the last. Here we will propose a unified framework for these three purposes, as well as its detailed internal mechanisms. Then we show how it can be easily applied to various legacy Web applications to develop innovative services.     

The boundaries for joint angles of isocomfort for sitting and standing males based on perceived comfort of static joint postures

This study presents data for the joint angles of isocomfort (JAI) in sitting and standing males based on perceived comfort ratings for static joint postures maintained for 60 s. The JAI value was defined as a boundary indicating joint deviation (an angle) from neutral posture, within which the perceived comfort for different body joint postures is expected to be the same. An experiment for quantifying perceived comfort ratings was conducted using the free modulus method of magnitude estimation. Based on experimental results, regression equations were derived for each joint posture, to represent the relationships between different levels of joint deviation/joint posture and corresponding normalized comfort scores. The JAI values were developed for nine verbal categories of joint comfort. The JAIs with the marginal comfort levels, one of the nine verbal categories used, for most joint postures around the wrist, elbow, neck and ankle were similar to the maximum range of motion (ROM) values for these joints. However, the JAIs with the marginal comfort category for back and hip postures were much smaller than the maximum ROM values for these joints. There were no significant differences in JAI expressed in terms of the percentage of the corresponding maximum ROM values between sitting and standing postures. The relative 'marginal comfort index', defined as the percentage of JAIs for the marginal comfort relative to the corresponding maximum ROM values, for the hip was the smallest among all joints. This was followed, in an increasing order of the marginal comfort index, by the lower back and shoulder, while the marginal comfort index for the elbow joint was the largest. The results of this study suggest that static postures maintained for 60 s cause greater discomfort for the hip joint than for the other joints studied, and less discomfort for the elbow than for the other joints. The data about JAIs can be used as guidelines for enhancing postural comfort when designing a variety of human-machine tasks where static postures cannot be eliminated.     

Worst-case response time analysis of real-time tasks under fixed-priority scheduling with deferred preemption

Fixed-priority scheduling with deferred preemption (FPDS) has been proposed in the literature as a viable alternative to fixed-priority pre-emptive scheduling (FPPS), that obviates the need for non-trivial resource access protocols and reduces the cost of arbitrary preemptions. This paper shows that existing worst-case response time analysis of hard real-time tasks under FPDS, arbitrary phasing and relative deadlines at most equal to periods is pessimistic and/or optimistic. The same problem also arises for fixed-priority non-pre-emptive scheduling (FPNS), being a special case of FPDS. This paper provides a revised analysis, resolving the problems with the existing approaches. The analysis is based on known concepts of critical instant and busy period for FPPS. To accommodate for our scheduling model for FPDS, we need to slightly modify existing definitions of these concepts. The analysis assumes a continuous scheduling model, which is based on a partitioning of the timeline in a set of non-empty, right semi-open intervals. It is shown that the critical instant, longest busy period, and worst-case response time for a task are suprema rather than maxima for all tasks, except for the lowest priority task. Hence, that instant, period, and response time cannot be assumed for any task, except for the lowest priority task. Moreover, it is shown that the analysis is not uniform for all tasks, i.e. the analysis for the lowest priority task differs from the analysis of the other tasks. These anomalies for the lowest priority task are an immediate consequence of the fact that only the lowest priority task cannot be blocked. To build on earlier work, the worst-case response time analysis for FPDS is expressed in terms of known worst-case analysis results for FPPS. The paper includes pessimistic variants of the analysis, which are uniform for all tasks, illustrates the revised analysis for an advanced model for FPDS, where tasks are structured as flow graphs of subjobs rather than sequences, and shows that our analysis is sustainable.     

Geometric algorithms for digitized pictures on a mesh-connected computer

Although mesh-connected computers are used almost exclusively for low-level local image processing, they are also suitable for higher level image processing tasks. We illustrate this by presenting new optimal (in the O-notational sense) algorithms for computing several geometric properties of figures. For example, given a black/white picture stored one pixel per processing element in an n × n mesh-connected computer, we give ?(n) time algorithms for determining the extreme points of the convex hull of each component, for deciding if the convex hull of each component contains pixels that are not members of the component, for deciding if two sets of processors are linearly separable, for deciding if each component is convex, for determining the distance to the nearest neighboring component of each component, for determining internal distances in each component, for counting and marking minimal internal paths in each component, for computing the external diameter of each component, for solving the largest empty circle problem, for determining internal diameters of components without holes, and for solving the all-points farthest point problem. Previous mesh-connected computer algorithms for these problems were either nonexistent or had worst case times of ?(n2). Since any serial computer has a best case time of ?(n2) when processing an n × n image, our algorithms show that the mesh-connected computer provides significantly better solutions to these problems.     

Compact disc standards: an introductory overview

The success of the compact disc (CD) as a storage medium for digital audio has, over the last ten years, resulted in a number of initiatives to use the CD for other applications as well, e.g., as read-only memory for computers, as a storage medium for audio-visual material for multimedia applications, and as a storage medium for photographs. Each of these applications poses additional requirements on how the corresponding information is stored and retrieved, resulting in a range of different CD standards. The functional specifications of these standards are each given a specific color for ease of reference: the Red Book for CD-DA, the Yellow Book for CD-ROM, the Green Book for CD-I, etc. This paper aims at giving an overview of the various CD standards by explaining what is specified in each of the colored books and by indicating how they relate to one another.     

A stress-strength interference model for predicting CTD probabilities

A model for predicting the incidence rate of carpal tunnel syndrome (CTS) for a given job, was developed using known biomechanical data, mechanical properties of human tendons and reliability engineering techniques to simplify the problem. In addition, time-dependent stress-strength interference theory was used to quantify the stress on the tendons during a job cycle, based on wrist position and grip strength and to estimate the tendon failure rate (or CTS incidence) for a given job. Higher failure probabilities were predicted for greater wrist deviations, for higher grasp forces, for females as compared to males, for wrist extension as compared to wrist flexion, and for two-fingered pinches as compared to four-fingered grasps. The predictions closely matched previously reported CTS incidence rates for a poultry thigh boning task.     

Numberings optimal for learning

This paper extends previous studies on learnability in non-acceptable numberings by considering the question: for which criteria which numberings are optimal, that is, for which numberings it holds that one can learn every learnable class using the given numbering as hypothesis space. Furthermore an effective version of optimality is studied as well. It is shown that the effectively optimal numberings for finite learning are just the acceptable numberings. In contrast to this, there are non-acceptable numberings which are optimal for finite learning and effectively optimal for explanatory, vacillatory and behaviourally correct learning. The numberings effectively optimal for explanatory learning are the K-acceptable numberings. A similar characterization is obtained for the numberings which are effectively optimal for vacillatory learning. Furthermore, it is studied which numberings are optimal for one and not for another criterion: among the criteria of finite, explanatory, vacillatory and behaviourally correct learning all separations can be obtained; however every numbering which is optimal for explanatory learning is also optimal for consistent learning.     

Static Analysis of Object References in RMI-Based Java Software

Distributed applications provide numerous advantages related to software performance, reliability, interoperability, and extensibility. This paper focuses on distributed Java programs built with the help of the remote method invocation (RMI) mechanism. We consider points-to analysis for such applications. Points-to analysis determines the objects pointed to by a reference variable or a reference object field. Such information plays a fundamental role as a prerequisite for many other static analyses. We present the first theoretical definition of points-to analysis for RMI-based Java applications, and we present an algorithm for implementing a flow- and context-insensitive points-to analysis for such applications. We also discuss the use of points-to information for corrupting call graph information, for understanding data dependencies due to remote memory locations, and for identifying opportunities for improving the performance of object serialization at remote calls. The work described in this paper solves one key problem for static analysis of RMI programs and provides a starting point for future work on improving the understanding, testing, verification, and performance of RMI-based software     

The strategic value of supply chain visibility: increasing the ability to reconfigure

To understand the role of supply chain visibility in creating strategic value, this study uses the dynamic capabilities view to uncover the nature of supply chain visibility. The study identifies four important constructs of supply chain visibility that are helpful in driving supply chain reconfigurability and thus improving supply chain strategic performance. They are visibility for sensing, visibility for learning, visibility for coordinating, and visibility for integrating. The results show that visibility for sensing has direct impact on supply chain strategic performance. Empirical evidence also supports that visibility for learning, visibility for coordinating, and visibility for integrating are important for enhancing supply chain reconfigurability, thus creating strategic value in supply chains. Supply chain visibility therefore enables firms to reconfigure their supply chain resources for greater competitive advantage. Implications of the results regarding the nature and the role of supply chain visibility in enhancing supply chain strategic performance are provided.