关于副本定位数据复制新技术的设计

随着计算机网络技术的不断发展,数据网格中副本定位对于网络性能的改进逐渐被人们所认识。本文基于对副本定位数据复制技术的研究,确定了副本创建网格环境后,建立了新技术的域内副本定位机制,提出了动态均衡映射技术域间动态均衡副本定位的方法,完成了系统副本定位模块功能的设计。测试表明,改进的技术数据网格中,域间定位数据元的增加对宿主节点的负载分配没有太大的影响。这一结论对发展大规模网格系统具有重要意义。     

比例差分修正的RSSI测距WSN节点定位研究

在无线传感器网络中节点定位技术占据着核心地位。基于传统RSSI的多边定位算法,提出了差分修正的井下无线传感器网络RSSI节点定位算法,通过不同锚节点之间的相互关系得到比例差分系数,将其应用在测量节点定位。目标未知节点首先读取在信标节点信息,利用卡尔曼滤波法除去信号中的噪声,获得更加精确的距离值,通过锚节点构建差分模型,利用比例差分的方法对RSSI测距进行修正,并对改进算法进行了仿真实验。结果表明,比例差分系数修正的RSSI测距定位算法的定位精度要远远高于传统RSSI测距定位算法,能够为井下的节点定位提供理论依据。     

无线传感器网络节点定位算法的研究综述

作为一种全新的信息获取和处理技术,无线传感器网络（WSN）可以在广泛的应用领域内实现复杂的大规模监测和追踪任务,而节点定位是大多数无线传感器网络应用的基础。介绍了无线传感器网络节点定位的概念和原理、节点定位计算的一般过程,讨论了现有的传感器网络节点定位算法的分类方法,着重综述了近年来该领域具有代表性的算法的原理和特点,简要介绍了节点定位算法的最新发展。在对现有算法进行了分析比较的基础上,通过归纳和总结,提出了基于移动锚节点的定位算法将成为以后研究热点的看法。     

基于移动信标的无线传感器网络混合节点定位算法

节点定位是无线传感器网络中的关键技术之一。本文在采用装备有GPS装置的移动信标的基础上,提出了加权质心定位方法和Unscented—KF滤波组合定位算法。算法首先利用加权质心定位方法,获得无线传感器网络未知节点的初步位置,再用Unscented—Kalman filter进一步提高定位精度。算法可以实现传感节点的低成本定位,容易达到很高的定位精度、可实现分布式定位计算。仿真结果显示,与算法较常用的极大似然估计相比,未知节点的定位精度有较大的提高。本算法定位过程中节点间无通信开销,计算量小,节省了宝贵的节点能量。在本文中算法是基于RSSI测距方式,它还可应用于TDOA,TOA等基于测距的定位算法中,具有较普遍的应用意义。     

无线传感器网络中节点定位算法的研究

在无线传感器网络中,节点定位是实现许多无线传感器网络应用的基础和支撑技术。现有传感器节点定位方法使用数量较多参考节点进行定位,而由于参考节点的成本、功耗、尺寸等原因使其难以大量使用。本文提出了一种基于三个移动参考节点的节点定位方法;同时,给出了以完成定位花费时间最小化为目标的优化算法。     

多目标遗传算法的应用研究

针对多目标优化问题,应用免疫遗传算法的基本思想,提出了一种求解满足带宽-时延约束问题的多目标遗传算法。在算法中设计了一种基于节点连接路径的具有树状结构的染色体表示方法并构造了路由选择的网络拓扑结构图。数值实验结果表明,文中提出的算法整体适应度和最优路径均符合该算法推断的理想结果。     

无线传感网大空间定位测量算法及精度评估

无线传感网结构参数对移动节点定位精度有重要影响。面对基于无线传感网大空间定位测量过程中的共性问题:测量距离约束和信号覆盖范围约束,提出了一种选择性大空间定位算法。面对移动节点特定的定位空间要求以及定位精度要求,采用蒙特卡罗方法研究了测距误差、信标网络参数配置对移动节点定位精度以及可定位空间的作用关系,提出的仿真算法模式对于设计评估满足一定精度要求的无线传感网络可定位空间探索具有一定的指导意义。     

农田环境无线传感器网络无锚节点定位算法

无锚节点定位算法不需要添加额外硬件,无需锚节点或少量参考节点,仅利用自身的无线收发器即可实现整个网络的节点定位,使定位成本大大降低,是解决由大量廉价节点组成大规模网络定位问题的较好方法.以农田应用为背景,提出一种无锚节点定位算法.该算法从普通节点中选取基准节点以形成坐标系,其他未知节点根据自己到基准节点的距离计算出自身坐标,最终得到所有节点的相对位置.还以实测求平均方法解决了无锚节点定位算法的累积误差问题.算法具有分布式特点,实现过程简单,实用性强.     

基于花授粉算法的曲面薄壁件定位布局优化

优化定位布局是减小薄壁件装夹变形的重要手段,现有研究大多以节点法向变形最小为优化目标而忽略其他方向上的变形,为此提出了一种新的基于花授粉算法的夹具布局优化方法。针对曲面薄壁件,在建立法向约束定位模型的基础上,通过应变能来描述所有方向上的变形,以薄壁件的整体应变能最小为目标,结合花授粉算法和基于Python语言的参数化有限元分析,实现薄壁件的定位布局寻优。最后以飞机蒙皮定位布局优化为例验证方法的有效性,并通过与遗传算法的对比表明,花授粉算法在优化薄壁件的定位布局时具有更优的性能。     

基于RSSI的无线传感网络协同定位算法及其应用

为了解决传统无线传感网络(WSN)中定位方法精度不高的问题,将协同定位的技术应用到无线传感网络的定位中。首先,通过对盲节点与参考节点的距离关系的分析,初步确定了盲节点区域;然后利用接收信号强度指示(RSSI)测距技术建立了盲节点之间的相对位置关系,并应用盲节点的相对位置关系多次迭代缩小盲节点区域,精确盲节点位置;在此基础上,提出了基于RSSI的无线传感网络协同定位算法。在Zigbee平台上对该算法进行了技术评价,与传统定位方法进行了对比实验,实验结果表明,基于RSSI的无线传感网络协同定位算法具有一定的精度优势,特别是当参考节点数目较少时,这种优势比较明显,具有良好的应用前景。     

On-demand QoS routing protocol based on energy and bandwidth requirement in Ad Hoc networks

Along with the emergence of real-time muhi-media, interactive service, real-time voice and other services calling for high quality of service, there should be a good network to support those services. Most present route algo-rithms with computational complexity hardly consider the restriction of node energy, so it degrades the whole capabil-ity of network. Bandwidth guarantee is one of the most crucial factors in real-time application, and this paper brings forward a distributed on-demand QoS routing protocol based on energy and bandwidth requirement. This QoS routing protocol makes use of bandwidth calculation algorithm and analyzes its route mechanism. The simulation results veri-fy its validity. The QoS routing protocol improves the packet delivery fraction and average end-to-end delay, prolongs the network lifetime, enhances the network performance and satisfies the route requirement for ad hoc networks.     

Reinforcement learning algorithms for robotic navigation in dynamic environments

The purpose of this study was to examine improvements to reinforcement learning (RL) algorithms in order to successfully interact within dynamic environments. The scope of the research was that of RL algorithms as applied to robotic navigation. Proposed improvements include: addition of a forgetting mechanism, use of feature based state inputs, and hierarchical structuring of an RL agent. Simulations were performed to evaluate the individual merits and flaws of each proposal, to compare proposed methods to prior established methods, and to compare proposed methods to theoretically optimal solutions. Incorporation of a forgetting mechanism did considerably improve the learning times of RL agents in a dynamic environment. However, direct implementation of a feature-based RL agent did not result in any performance enhancements, as pure feature-based navigation results in a lack of positional awareness, and the inability of the agent to determine the location of the goal state. Inclusion of a hierarchical structure in an RL agent resulted in significantly improved performance, specifically when one layer of the hierarchy included a feature-based agent for obstacle avoidance, and a standard RL agent for global navigation. In summary, the inclusion of a forgetting mechanism, and the use of a hierarchically structured RL agent offer substantially increased performance when compared to traditional RL agents navigating in a dynamic environment.     

采埃孚针对中巴推出的独立悬架

随着全新开发的采埃孚独立悬架RL55EC面世,汽车制造商现可为中巴配备来自采埃孚的前桥系统。针对中巴开发的独立悬架采用双叉臂设计,这种设计多年来一直广泛运用于低地板巴士、低入口双层巴士和公路客车中。RL55EC可实现更高舒适度、转向半径更小、侧倾更少,并且还减少了非簧载质量。     

网格环境下多服务质量约束的复合服务调度机制

目前,由于没有一个动态、可扩展的服务组合模型,在服务网格环境中缺乏满足多性能目标约束的、复合服务的调度机制。为此,在分析动态服务调度机制基础上,将服务质量约束引入到状态图工作流模型中,提出一种多服务质量约束的动态组合服务模型,给出了在服务组合过程中保持服务组件之间服务质量一致性的方法,并将复合服务的调度问题（即执行路径的动态选择问题）归结为多属性决策问题。采用简单加权法,以保证组合后的服务满足综合服务质量约束。通过实现的服务调度组件验证了该机制的可行性和有效性。     

Study on manufacturing grid resource service QoS modeling and evaluation

Current research on manufacturing grid (MGrid) systems has mainly concentrated on its concept, architecture, application prototype platform, and application foreground. Absent from the trend is the quality of service (QoS) of MGrid, such as QoS modeling, QoS evaluation, and QoS-based scheduling, which play a very important role in MGrid resource management. The related topics about MGrid and QoS are investigated in this study. The characteristics of QoS associated with its management requirements in MGrid are then further studied. Classification and modeling of MGrid QoS are investigated from three different perspectives: QoS whole-lifecycle management, MGrid architecture view, and QoS attribute parameters. The measurement and evaluation models of QoS parameters in MGrid are presented. A simple case study is described to illustrate how the proposed works can be applied to MGrid resource service management.     

基于交通流模型的预约电梯群控算法研究

针对传统电梯群控系统乘客乘梯时间的不可知性及随之导致的梯群服务效率低、能耗大等问题,对电梯群控系统的结构、呼梯方式、派梯算法等方面进行了研究,提出了一种含有目的层预约设备的电梯群控系统,目的层预约设备可得到含有目的层信息的确定呼梯信号,利用交通流作为输入,构建并训练了模糊神经网络,实现了交通流模型的识别。最后,基于VB和Matrix VB编写了电梯群控系统的仿真系统,并进行了仿真计算。研究结果表明,基于交通流模型的目的层预约电梯群控算法能在不同交通模式下采用不同的群控策略,实现了不同交通模式下电梯群的优化控制,提高了系统的运行效率和性能,验证了算法的有效性与可行性。     

面向服务质量的交互式Web服务选择

在大量相似服务共存竞争环境下,为了实现面向服务质量的Web服务选择,分析了Web服务质量综合、模糊、动态和可配置特征,指出了当前服务描述和查找标准在服务质量信息描述和应用方面的不足。提出了Web服务的服务质量语义描述模型;设计了基于综合模糊评价系统的柔性可配置Web服务的服务质量需求语义描述模型;提出了改进的服务描述、查找和集成过程,利用基于合同网的交互协议规范的服务提供方、中介服务和服务用户3方协作,实现了面向服务质量的交互式Web服务选择。     

Quality of service in manufacturing networks: a service framework and its implementation

Due to the continuous growth in the application of networks in manufacturing, quality of service (QoS) has become an important issue. In this paper, the concept of QoS for manufacturing networks is discussed. To provide overall performance assurance for manufacturing networks, a service framework integrating the QoS mechanisms of the networked resource service management function and the communication networks is proposed. The novel framework maps an application to resource services and then to communication networks, adopts an intelligent optimisation algorithm for QoS management of resource services, and provides QoS schemes for data transfer across communication networks. A prototype implementation has been realised and a set of simulation experiments conducted to evaluate the validity of the framework. The results obtained demonstrate the ability of the framework to satisfy the various performance requirements posed by such applications and provide efficient overall performance assurance for manufacturing networks.     

MULTIPLE ELECTRONIC CONTROL UNITS CALIBRATION SYSTEM BASED ON EXPLICIT CALIBRATION PROTOCOL AND J1939 PROTOCOL

The rising number of electronic control units （ECUs） in vehicles and the decreasing time to market have led to the need for advanced methods of calibration. A multi-ECU calibration system was developed based on the explicit calibration protocol （XCP） and J1939 communication protocol to satisfy the need of calibrating multiple ECUs simultaneously. The messages in the controller area network （CAN） are defined in the J1939 protocol. Each CAN node can get its own calibration messages and information from other ECUs, and block other messages by qualifying the CAN messages with priority, source or destination address. The data field of the calibration message is designed with the XCP, with CAN acting as the transport layer. The calibration sessions are setup with the event-triggered XCP driver in the master node and the responding XCP driver in the slave nodes. Mirroring calibration variables from ROM to RAM enables the user to calibrate ECUs online. The application example shows that the multi-ECU calibration system can calibrate multiple ECUs simultaneously, and the main program can also accomplish its calculation and send commands to the actuators in time. By the multi-ECU calibration system, the calibration effort and time can be reduced and the variables in ECU can get a better match with the variables of other ECUs.     

A reverse logistics diagnostic tool: the case of the consumer electronics industry

The consumer electronics (CE) industry has high turnovers and a growing demand, such as on the home entertainment segment. At the same time, it generates e-waste of the order of a dozen million tons, about one quarter of the world's total. With the purpose of improving the environmental performance of businesses, the Waste Electrical and Electronic Equipment (WEEE) Directive was put in place in Europe. Given the high competitive environment of this industry, WEEE could be a clue for competitive edge. To create an environmental and economic win-win situation, however, companies have to master reverse logistics (RL). This is particularly challenging in fast clockspeed environments, as it is the case for the CE industry. In this paper, we develop a theoretically and empirically grounded diagnostic tool for assessing a CE company's RL practices and identifying potential for RL improvement, from a business perspective. To theoretically ground the tool, we combine specific CE literature with general theory on reverse logistics management and performance improvement. To empirically ground the tool, we collect field data by combining quantitative (a multiactor survey) with qualitative (interviews and company visits) methods. We demonstrate how our tool can be used to create awareness at senior management about the reverse logistics maturity state.