Energy-efficient cooperative data aggregation for wireless sensor networks

Recently, cooperative communication mechanism is shown to be a promising technology to improve the transmit diversity only by a single transceiver antenna. Using this communication paradigm, multiple source nodes are able to coordinate their transmissions so as to obtain energy savings. As data aggregation is one of the most important operations in wireless sensor networks, this paper studies the energy-efficient data aggregation problem through cooperative communication. We first define the cooperative data aggregation (CDA) problem, and formally prove that this problem is NP-Hard. Due to the difficult nature of this problem, we propose a heuristic algorithm MCT for cooperative data aggregation. The theoretical analysis shows that this algorithm can reach the approximate performance ratio of 2. Moreover, the distributed implementation DMCT of the algorithm is also described. We prove that both centralized and distributed algorithms can construct the same topology for cooperative data aggregation. The experimental simulations show that the proposed algorithms will decrease the power consumption by about 12.5% and 66.3% compared with PEDAP and PEGASIS algorithms respectively.     

高速突发模式误码测试仪的FPGA实现方案

突发模式误码测试仪与一般连续误码测试仪不同,其接收端在误码比对前要实现在十几位内,对具有相位跳变特点的信号进行时钟提取和数据恢复,并且在误码比对时须滤除前导码和定界符,仅对有效数据进行误码统计。本文提出一种基于FPGA实现的高速突发模式误码测试仪设计方案,并介绍该方案的总体设计过程,以及FPGA中主要功能逻辑模块的工作原理和控制系统的设计。该测试仪应用于1.25GHz GPON系统突发式光接收模块的误码测试中,具有较好的性能和实际意义。     

融合通信系统中分布式存储引擎的研究

融合通信是当今计算机应用领域研究热点之一,人们对融合通信系统中应用服务的要求也越来越高.在数据存取方面,基于传统关系型数据库或者基于传统文件系统的存储方式已经越来越不能满足应用的需求.随着Hadoop技术以及相关子系统的发展,分布式存储的优势日渐明显.因此,本文在分析HBase、Hive各自特点及其体系结构的基础上,结合融合通信具体项目提出了基于HBase-Hive集成设计的存储引擎设计方法,以此来解决融合通信系统中数据安全性、数据获取效率等方面不满足的情况.通过对比实验表明,该设计方案提高系统数据查询获取效率,也为后续数据挖掘方面的开发做好准备.     

基于ARM—Linux系统与组态王Modbus／TCP通讯的研究与实现

Modbus／TCP工业以太网是运行在TCP／IP协议栈上的Modbus报文传输协议,组态王（Kingview）是国内组态软件龙头。分析了Modbus／TCP的协议构成及其体系结构和组态王中的莫迪康Modbus／TCP协议,在嵌入式ARM9和Linux操作系统平台上实现了Modbus／TCP协议与组太王6．55的通讯。方案能有效实现工业现场的Arm—Linux系统与组态王的Modbus／TCP通信功能。     

沼光一体化发电测控系统

分析了沼光一体化系统结构和工作原理,设计了以Atmega88为主控制器,以GSM无线通信模块为远程控制媒介的沼光一体化发电测控系统.并详细阐述了系统硬件电路设计的结构、原理图、元件选型和技术指标等,然后给出了系统软件设计实现的工作流程等.     

网络编码调度算法的研究

近年来,网络编码作为提高通信系统吞吐量一种手段。在多播的通信网络,网络中各个传送节点结合动态变化的网络情况,对不同信息流的数据包进行编码处理,从而减轻局部节点的阻塞,提高了整个通信系统的性能。文章主要工作要体现在典型无线通信网络中,引入动态网络编码调度算法,提高无线通信系统的网络编码增益和系统吞吐量;探讨在自适应无线通信系统下,如何适当的使用自适应技术,使得动态网络编码调度算法的作用发挥到最大。各个节点间的发送端更应选取适合的自适应技术,来提高无线通信系统性能。通过MATLAB仿真显示,带有自适应技术的无线网络,在动态网络编码调度算法作用下,对改进系统性能有着更加重要的现实意义。     

Win CE平台下嵌入式故障诊断专家的设计

针对高科技产品专业性强、系统结构复杂、故障分析困难等问题,本设计以故障诊断的理论和方法为基础,提出了一种基于专家系统的故障诊断设计方案。设计构造了故障诊断专家系统的整体框架,探讨了专家系统中知识库的建立、推理机制以及人机界面设计等问题。     

QoS Filtering and Resource Reservation in an Internet Environment

Multimedia group applications often operate in an environment where the various participants are located on systems and communication links with different capabilities. Mechanisms are required that ensure full-quality media for high-performance workstations but lower-quality media for playout at low-end systems. QoS filters have been proposed as a way to adapt QoS to the user specified level by changing the structure of a media stream in a well defined way. Resource reservation and QoS filter instantiation should be closely integrated since both represent one particular aspect of the provision of individualistic QoS for heterogeneous users in multipeer communications. The Internet reservation protocol RSVP is receiver oriented and allows each receiver to specify its resource requirements. However, no actual mechanisms are defined that adapt the data stream to the receiver specified QoS requirements.In this paper we present an enhanced version of RSVP (called RSVP++) that integrates resource reservation and QoS filter control. In order to achieve this integration we extend the RSVP functional model and define a new QoS service class. RSVP++ can coexist with common RSVP systems, thus, openness and interoperability of the system are ensured.     

Systems programming for data communications on minicomputers

This paper examines some of the special considerations which apply to the development of such software for minicomputers. These are treated under the following general categories:

• loading and throughput
• the external interfaces of the system software
• the internal structure of the system software
• developing the software

.     

美国弹道导弹防御C2BMC系统发展综述

指挥控制、作战管理和通信（command and control,battle management and communications,c2BMC）系统是美国弹道导弹防御的核心。通过详细分析C2BMC系统的功能、目标和研制进展,找出了其薄弱环节,在此基础上提出了一些对策与思考,对弹道导弹的发展建设具有重要指导意义。