船用柴油机冗余CANopen过程数据对象可调度性与一致性问题研究

针对热冗余通讯在增加船用柴油机电子管理系统通讯可靠性时,默认及冗余总线在不同的抖动下存在数据接收方无法接收两路CAN总线报文的问题,提出以时间戳报文统一系统内所有节点的时间信息,以X+n/Y×TInhibit的偏移量作为异步通讯周期发送的起始时间,以X/Y×TInhibit为时间窗长度,将所有过程数据对象(PDOs)放入不同的时间窗内发送,降低瞬时负荷率,增强可调度性;提出最大延迟时间检测方法,提高两路数据的一致性。通过试验对比冗余CANopen的两种传输模式,结果表明,该方法能有效提高数据的可调度性和一致性。     

Standard color liquid crystal displays by a dimming technology

Dimming technologies have been used in liquid crystal display (LCD) products, especially for mobile applications, to reduce power consumption. It is widely known that dimming technologies tend to degrade the color accuracy. This article, however, presents that color performance of a dimmed LCD is better than a conventional one. We show a max method, one of dimming methods, converting an input digital data into higher values that have less color shift phenomenon. We propose how to compare the color performance of original and dimmed colors based on a modified standard. The average value of measured Δu′v′ of 25 dimmed colors was 0.0040, whereas that of the original colors was 0.0190. In addition, the average value of measured Δ of 25 dimmed colors was 2.40, whereas that of the original colors was 9.24. The measured results prove that the dimming technology can make LCD better in not only power consumption but also color performance. This article is the world's first report that breaks the usual stereotype on dimming technologies. This work proposes a dimmed LCD as a standard color display. © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 480–485, 2014     

布尔表达式匹配问题研究

提出了布尔表达式匹配问题,并给出了它的形式化定义;提出了一个解决布尔表达式匹配问题的通用算法框架,并在此框架上给出了一种算法及其改进;通过理论分析和实验数据给出了影响布尔表达式匹配算法性能的因素和它们之间的关系.     

三峡工程永久船闸单级闸室仿真系统制作简介

为整体展示三峡船闸闸室及输水系统结构,为船闸检修维护提供科学直观的依据,选用Autodesk公司开发的基于PC系统的三维动画渲染和制作软件3ds max以及基于3ds max的著名风景插件dreamscape进行三维模型的构建和表现,探讨了演示方案设计中对界面进行交互性设计以及通过美学法则的运用来增强画面艺术表现力的方法。     

绘制效果图是建筑设计人员必须具备的基本功

阐述设计人员绘制效果图的必要性、令人忧郁的现状以及学习效果图的途径，并结合两幅图例重点阐述绘制效果图的若干实用技巧。     

基于双子代数理论的网络建模与分析

本文研究了双子代数尤其是极大代数理论在计算机网络建模与性能分析中的应用.采用极大代数分析了令牌桶的输入输出特性,得到了(b,ρ)令牌桶在极大代数下的状态空间方程组与传输矩阵;提出了基于极大代数的网络演算,定义了极大到达曲线与极大服务曲线,利用这两个概念得出了极大代数下有关延迟以及输出流突发性的定理.最后采用基于极大代数...     

基于多方向二进小波变换的遥感图像特征提取方法

在分析不同分辨率图像空间特性的基础上，提出了一种基于多方向二进小波变换的图像特征提取方法．该方法首先对图像进行小波变换，然后由二进小波变换的模的局部极大值检测信号突变点位置及奇异性大小，实现图像的边缘特征提取．通过对遥感图像样本的仿真实验表明，基于多方向二进小波变换的图像边缘特征提取方法可以取得较好的边缘特征提取效果．     

供应链的效率与协调问题研究

目的 研究供应链总体行为最优的时候，供应链上各个利益主体的状态和他们之间的关系．方法 依据逆向思维的原则，从当前供应链协调研究的热点方法——供应链契约理论相反的方向出发，由供应链效率的定义开始，逐步推导．结果 给出了供应链协调的等效率原则、供应链协调的方向和范围及实现等效率原则的途径．结论 供应链协调的等效率原则使供应链管理难题和目标具有了量化指标和依据，有利于供应链契约的设计和对供应链的评价．可以作为供应链协调和供应链评价的目标和评价准则．     

蓄电池充电析气量试验

针对电动自行车用蓄电池的特点,使用阀控式铅酸蓄电池析气量收集试验装置,通过调整三阶段式充电器的恒压充电电压值参数进行试验,通过收集充电过程中蓄电池的析气量,分析蓄电池充电过程中充电电流、电压及析气量的关系。认识到三段式充电器的恒压充电电压值高低对蓄电池析气量影响最大,通过控制恒压充电电压值,可以降低充电过程对蓄电池寿命的影响。     

Score normalization in multimodal biometric systems

Multimodal biometric systems consolidate the evidence presented by multiple biometric sources and typically provide better recognition performance compared to systems based on a single biometric modality. Although information fusion in a multimodal system can be performed at various levels, integration at the matching score level is the most common approach due to the ease in accessing and combining the scores generated by different matchers. Since the matching scores output by the various modalities are heterogeneous, score normalization is needed to transform these scores into a common domain, prior to combining them. In this paper, we have studied the performance of different normalization techniques and fusion rules in the context of a multimodal biometric system based on the face, fingerprint and hand-geometry traits of a user. Experiments conducted on a database of 100 users indicate that the application of min–max, z-score, and tanh normalization schemes followed by a simple sum of scores fusion method results in better recognition performance compared to other methods. However, experiments also reveal that the min–max and z-score normalization techniques are sensitive to outliers in the data, highlighting the need for a robust and efficient normalization procedure like the tanh normalization. It was also observed that multimodal systems utilizing user-specific weights perform better compared to systems that assign the same set of weights to the multiple biometric traits of all users.