A Novel Practical Cooperative Diversity Method for the Power-Limited Wireless Sensor Network

A novel practical cooperative diversity method for power-limited wireless sensor network system was proposed. At first, the system model was presented and the cooperation problem is formulated under the minimum outage probability criterion, then the focus was put on the power efficiency of system, such as the relay selection, cooperation strategy and power allocation etc. At last the uniform procedure of the proposed method was given. The results of the simulation clearly demonstrate that our method not only has the properties of simple operation and wide applying scope, but also outperforms those of current classical methods on the aspect of outage probability under the basis of the same power limitation.     

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结合传统数据通信网络的QoS保障机制研究成果及无线传感器网络自身特点,针对青藏冻土地温自动监测的应用特点,提出能量的高效利用、数据的可靠传输和网络生存周期的有效延长是其QoS保障的主要需求和关键点。并以此关键点为目标,研究了青藏冻土地温监测的无线传感器网络QoS保障机制的能量优化策略,提出了非均匀分簇路由算法并进行了深入分析。最后,通过仿真验证及在青藏冻土地温自动监测的试点应用,验证非均匀分簇路由算法能有效提高网络的生命周期和数据传输可靠性。研究成果将为建立无线传感器网络相关应用系统提供理论支撑和模型参考。     

基于移动基站的动态无线传感器网络

针对无线传感器网络(WSN)中的“路由热点”问题,提出了在簇头移动的前提下基于事件驱动的基站簇头混合移动策略BS-CH HMS(base station-cluster head hybrid mobile strategy).该策略根据CH(cluster head)移动时的能量损耗确定CH的移动轨迹,制定基站的协作...     

基于工业现场的无线自组网设计与应用

从工业现场应用实际出发,以工业无线自组织网络高可靠、实时通信问题为研究对象,设计了一种更适合工业现场应用的轻量级无线自组织网络通信协议(TWRP),并通过仿真和现场运行数据验证了在提高通信可靠性、实时性方面具有有益效果。     

通用无线电数据链自动测试系统可靠性设计

介绍了通用无线电数据链自动测试系统的可靠性设计需求,并重点从硬件和软件两方面介绍了系统硬件电磁兼容设计和软件可靠性设计以及测试等.应用结果表明,通过较全面可靠性设计,系统工作稳定可靠,满足了自动测试的要求.     

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部署在铁路路基监测区域内的无线传感器网络（WSN）,由于节点能量和带宽等资源的限制,要求数据的采集、处理、传输满足低能耗、高效率和高可靠性. 本文提出面向智能监测的无线传感器网络分簇部署策略,在感兴趣的区域内部署尽量多的节点,并根据数量类型、环境特征等因素将网络以簇为单位进行划分. 以簇为单位,采用自适应加权数据融合处理技术,将采集的地温数据按照精度分别乘以权重值再进行平均值处理,有利于降低数据冗余度,提高数据准确度和采集效率. 仿真性能分析表明,该方法可以显著提高数据传输效率,降低网络能耗,延长网络生命周期.     

A Distributed Virtual Backbone Formation for Wireless Ad Hoc and Sensor Networks

The virtual backbone is an approach for solving routing problems in wireless ad hoc and sensor networks. A connected dominating set (CDS) was proposed as a virtual backbone to improve the performance of wireless networks. The quality of a virtual backbone is measured not only by approximation factor, which is the ratio of its size to that of minimum CDS, but also time complexity and message complexity. In this paper, a distributed algorithm is presented to construct a minimum CDS for ad hoc and sensor networks. By destroying triangular loops in the virtual backbone, the proposed algorithm can effectively construct a CDS with smaller size. Moreover, our algorithm, which is fully localized, has a constant approximation ratio, linear message and time complexity, and low implementation complexity. The simulation results and theoretical analysis show that our algorithm has better efficiency and performance than conventional approaches.     

Network lifetime global optimization for multi-source and single-sink topology in wireless sensor networks

The multi-source and single-sink (MSSS) topology in wireless sensor networks (WSNs) is defined as a network topology, where all of nodes can gather, receive and transmit data to the sink. In energy-constrained WSNs with such a topology, the joint optimal design in the physical, medium access control (MAC) and network layers is considered for network lifetime maximization (NLM). The problem of integrating multi-layer information to compute NLM, which involves routing flow, link schedule and transmission power, is formulated as a non-linear optimization problem. Specially under time division multiple access (TDMA) scheme, this problem can be transformed into a convex optimization problem. To solve it analytically we make use of the property that local optimization is global optimization in convex problem. This allows us to exploit the Karush-Kuhn-Tucker (KKT) optimality conditions to solve it and obtain analytical solution expression, i.e., the globally optimal network lifetime (NL). NL is derived as a function of number of nodes, their initial energy and data rate arrived at them.Based on the analysis of analytical approach, it takes the influence of data rates, link access and routing method over NLM into account. Moreover, the globally optimal transmission schemes are achieved by solution set during analytical approach and applied to algorithms in TDMA-based WSNs aiming at NLM on OMNeT<++> to compare with other suboptimal schemes.     

面向智能内河航运通信的无线信道测量与典型信道特征

为了明确新一代移动通信技术服务智能内河航运的作用机理,基于内河航运无线通信发展现状和通信环境特殊性,搭建了4G和5G临时无线通信网络,分别对以长江武汉段为例的典型内河通信场景开展了实际信道测量活动,以探寻内河航运无线通信特性的影响因素;利用高精度无线信道测量仪采集了信道传输函数、信号接收强度、时延等信道参数;基于无线传播理论和抽头延迟线模型,提取了传输路径损耗、功率时延分布、时延扩展、多普勒扩展等典型无线信道特征;基于信道典型特征参数,预测了4G和5G无线传播信号在内河场景下的有效覆盖范围及信号传输速率,探究了内河航运无线通信的多径来源和时延分布。测量和分析结果表明：内河航运无线通信中,桥梁、岸边建筑、过往大型船舶等均为无线传播信号多径效应的主要来源;桥梁可以造成最大18.0 dB的衍射损耗,岸边建筑和过往船舶遮挡会分别造成25.0、10.6 dB的能量衰减;4G无线通信的最大测量速率为95.32 Mb·s^-1,而5G通信测量速率最高可达0.72 Gb·s^-1;大型过往船舶还会造成均方根时延扩展增大约754.94 ns。可见,根据内河通信特殊环境构建合适的新一代移动通信专网,可以更好地为智能航运提供通信保障服务。     

交通运输网络中两个结点间有流量约束的最小费用最大流算法

对交通运输网络最小费用最大流的分配是在满足容量限制条件和流量守恒条件下,基于总费用最低的原则进行的,但在实际应用中,通常对交通运输网络中两个结点之间的流量有具体的要求和约束限制条件.针对交通运输网络中两个结点之间有流量约束的最小费用最大流问题进行了分析,总结了两个结点之间的流量不能超过限制值、不能低于限制值以及在一定范围内的3种约束条件.基于连续最短路算法中构造伴随增流网络的思路,设计了这3种约束限制条件下的最小费用最大流分配算法.利用这个算法,可以解决交通运输网络中两个结点之间有流量约束的最小费用最大流分配问题.在交通运输领域,两个结点之间有流量约束的最小费用最大流问题普遍存在,这些算法也为解决实际的运输问题提供了应用基础.     

基于BP神经网络的分销商绩效指标评价及应用

针对当前评价分销商绩效的方法所存在的不足,提出一种基于BP神经网络的分销商绩效评价方法.首先建立分销商绩效评价指标体系,然后根据指标体系,设计BP神经网络模型,并给出了可行的评价程序.在计算方法上,用神经网络工具箱进行计算.通过学习样本的训练和测试,使模型的误差达到预定的范围内.最后,利用该模型对江苏某动力机械厂的分销商绩效指标进行了评价,同时探讨了BP神经网络在分销商绩效指标评价中的特点和适用性.     

基于路网拓扑结构和标志性地物的指路标志设计

指路标志是一种标识路网、传递道路信息的重要交通流管控执行设施。为使指路标志携带有效信息并实现快捷诱导功能,在路网拓扑结构的基础上利用聚类分析、圈层覆盖和层次分析三种方法对基于标志性地物的指路标志设计过程进行建模,将获取的所有标志性地物数据和与之对应的道路网拓扑数据进行聚类分析,选取具有代表性的标志性地物作为指路标志的标示内容。将道路网和地物的影响范围划分为三个层次,利用圈层覆盖法确定所得标志性地物的影响范围,并将其作为标示内容的标示方向。运用层次分析法进行标示建模,确定在指路标志携带能力有限的情况下标示内容的选取优先权。最后通过算例分析验证模型的有效性。     

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在对概率神经网络(PNN)的分类机理、输入向量选取和网络设置分析的基础上，建立了用于识别两类事件模式(无事件模式和有事件模式)的事件检测PNN模型。采用高速公路路段Ⅰ-880实地线圈数据集和事件数据集验证模型，通过比较PNN模型与多层前向神经网络(MLF)模型的结果，发现无论对于向北、向南或混合方向的高速公路事件检测,PNN模型的检测率(DR)比MLF模型高；平均检测时间(MTD)比MLF模型短；但误报率(FAR)较高。概率神经网络是高速公路事件检测的一种有效算法，其在理论基础、算法和学习速度等方面比多层前向神经网络具有优势。     

Interference and Spectral Efficiency Analysis in Two-hop Cellular Network with Fixed Relays in FDD Mode

IntroductionRelaying is well known for its potential of ex-tending the high data rate coverage of a single basestation and reducing infrastructure deploymentcosts. Moreover, it is efficient in solving the cov-erage problem behind the obstacles and eliminatingblack spots, which even can not be solved by intro-ducing smart antenna technology[1,2]. Some dumbrelays (analog repeaters) have been adopted[1]in2 G and 3 G systems. But in such scenarios, thesignals received are forwarded without any si…     

A Statistical Parameter Analysis and SVM Based Fault Diagnosis Strategy for Dynamically Tuned Gyroscopes

Gyro's fault diagnosis plays a critical role in inertia navigation systems for higher reliability and precision. A new fault diagnosis strategy based on the statistical parameter analysis (SPA) and support vector machine (SVM) classification model was proposed for dynamically tuned gyroscopes (DTG). The SPA, a kind of time domain analysis approach, was introduced to compute a set of statistical parameters of vibration signal as the state features of DTG, with which the SVM model, a novel learning machine based on statistical learning theory (SLT), was applied and constructed to train and identify the working state of DTG. The experimental results verify that the proposed diagnostic strategy can simply and effectively extract the state features of DTG, and it outperforms the radial-basis function (RBF) neural network based diagnostic method and can more reliably and accurately diagnose the working state of DTG.     

交通运输网络能力限制路段分析及扩能优化研究

交通运输网络是交通运输系统的重要组成部分,确定交通运输网络中的能力限制路段,设计合理的路网扩能优化方案都是交通运输部门需要面临的问题。本文依据最大流理论制订了路网能力限制路段的确定方法,建立了以换算扩能费用最小为目标的扩能优化模型并设计了相应的求解算法。算例表明,本文研究的模型及算法是有效的,且扩能优化方案中的扩能路段与路网能力限制路段基本上是一致的。     

公路网建设规模与经济发展协调性分析

基于2000—2012年太仓市的相关数据,运用主成分分析法,计算太仓市公路网规模与经济发展的主成分得分,并进行排序、等级差和相关性分析,对太仓市公路网建设与经济发展水平的协调性进行实证分析。在此基础上,提出进一步促进太仓市公路网建设和经济协调发展的对策。     

Analysis of the pencil of conics with double complex contact and its application to camera calibration

In this paper,we introduce a novel class of coplanar conies,the pencil of which can doubly contact to calibrate camera and estimate pose.We first analyze the properties of con-axes and con-eccentricity ellipses, which consist of a natural extending pattern of concentric circles.Then the general case that two ellipses have two repeated complex intersection points is presented.This degenerate configuration results in a one-parameter family of homographies which map the planar pattern to its image.Although it is unable to compute the complete homography,an indirect 3-degree polynomial or 5-degree polynomial constraint on intrinsic parameters from one image can also be used for camera calibration and pose estimation under the minimal conditions.Furthermore, this nonlinear problem can be treated as a polynomial optimization problem(POP) and the global optimization solution can be also obtained by using SparsePOP(a sparse semidefinite programming relaxation of POPs). Finally,the experiments with simulated data and real images are shown to verify the correctness and robustness of the proposed technique.     

Refrigeration Performance Analysis and Its Applicability of a New Metal Hydride Couple in Auto Air-conditioning

With COP and dynamic characteristics in refrigeration cycle as criteria,a new metal hydride couple--LaNi4.61Mn0.26Al0. 13/La0.6Y0.4Ni4.8Mn0.2 was selected by establishing calculation procedure and metal hydride selection model. The experimental results show that the refigeration cycle of the selected couple is good in the performance. The recovered waste heat and refrigeration power from exhaust gas of several kinds of automobile are calculated by waste-heat formula ,coefficient RQ and COP. Refrigeration cycle of the new couple can satisfy the air-conditioning requirement of truck and car and is not enough in passenger car,according to the respective cooling load.     

车载Ad Hoc网络中位置服务机制研究与设计

作为移动Ad Hoc网络具体应用之一的车载Ad Hoc网络具有许多自身特征,如车辆节点处于十字路口时存在许多等待绿灯的静止节点以及通行速度相对缓慢的通行节点。在考虑了上述特征之后,提出了一种适用于车载Ad Hoc网络的新的位置服务设计方案,该设计方案将位置服务与基于位置的路由协议如无状态路由协议GPSR进行融合。在城市场景下的仿真结果表明:通过与GLS和HLS相比,ILSV获得相当高的查询成功率并具有较优的可缩放性。