国内外码头岸电系统技术应用及发展综述

从2000年开始,欧美等发达国家就将码头岸电系统技术应用在各种类型的港口码头,甚至与混合动力船舶联合使用。我国2009年才首次采用岸电系统,随着岸电系统写入“十二五”规划,并作为防治城市大气污染的措施之一,码头岸电系统成为建设绿色、智慧港口的重要组成部分。对岸电技术近20年来在国内外的应用和发展进行比较,对岸电系统的组成和配置方案进行总结,在综合分析的基础上对岸电技术的发展方向进行预测。     

欧标体系下码头打入桩施工前期策划及工作流程

码头打入桩施工前期的策划主要包括选择打桩设备、制定沉桩控制标准和现场试验等,是打入桩设计施工能否顺利实施的关键.而中、欧标准的差异会让熟悉国内标准的中国工程师对欧标体系下打入桩施工前的策划工作感到困扰.从规范条文出发,介绍欧标体系下码头打入桩施工前期的主要策划工作,并通过与中国规范相关内容的对比,总结中、欧标准的异同以...     

Switching between antenna subset selection and quasi-orthogonal space-time block code in presence of correlation

We address the problem of adaptive modulation and coding scheme (AMCS) for a multi-input multioutput (MIMO) system in presence of time-varying transmitting correlation. Antenna subset selection and quasiorthogonal space-time block code (QOSTBC) have different error performances with different signal-to-noise ratios (SNRs) and in different spatial correlation scenarios. The error performance can be improved by selecting an appropriate transmission scheme to adapt to various channel conditions. The maximum distance criterion is the simplest and very effective algorithm for the antenna subset selection without needs of complex calculation and channel state information at transmitter (CSIT). The minimum error performance criteria and the simplified linear decision strategy are developed for constant transmission rate traffic to select the optimal transmission scheme. It can dramatically decrease algorithm complexity for obtaining error probability according to the known quantities comparing with using instant CSIT. Simulation results show that, remarkable performances including low SNR and weak spatial correlation at the expense of simple calculation and almost no bandwidth loss by adopting AMCS can be achieved. The proposed AMCS improves robustness of slowly varying spatial correlated channels.     

机车配件检修质量与跟踪管理信息系统的研究

机车配件检修质量与跟踪管理信息系统集成计算机信息技术、设备检测和条码等技术对机车配件进行管理,该系统主要由配件检测试验、配件寿命、配件跟踪、配件质量控制和配件质量寿命跟踪分析子系统构成.提出系统的功能模块,详细阐述各功能模块的主要程序流程及实现方法.实际运用中取得良好的效果.     

An Improved Group Space-Time Block Code Through Constellation Rotation

A new improved group space-time block code （G-STBC） based on constellation rotation for four transmit antennas was proposed. In comparison with the traditional G-STBC coding scheme, the proposed space-time code has longer code length and adopts proper rotation-based symbols, which can increase the minimum distance of space-time codes and thereby improve code gain and achieve full diversity performance. The simulation results verify that the proposed group space-time code can achieve better bit error performance than both the traditional group space-time code and other quasi-orthogonal space-time codes. Compared with Ma＇s full diversity full rate （FDFR） codes, the proposed space-time code also can achieve the same excellent error performance. Furthermore, the design of the new space-time code gives another new and simple method to construct space-time codes with full diversity and high rate in case that it is not easy to design the traditional FDFR space-time codes.     

宽带噪声干扰对M码接收机的影响分析

在介绍M码信号的特点和接收原理的基础上,根据载波跟踪环的门限所确定的等效载噪比建立了宽带噪声干扰下的M码信号模型,从而分析得到干扰有效时的最小入射功率。通过建立干扰信号链路方程得出干扰源距离与干扰功率的关系,最后进行了仿真验证表明宽带噪声干扰对M码信号是一种有效的干扰方式。     

宇通客车气压ABS原理及检测

介绍宇通客车气压ABS的组成,每个元件的功能、测试方法以及ABS的闪码诊断程序和故障码含义.     

管道检测中伪随机码技术应用研究

将伪随机码技术引入管道检测,通过对伪随机码信号的分析,提出根据接收信号幅频特性中的幅度相差23 dB的频率点及环境的其他参数,计算出管道绝缘电阻的参数,从而确定管道腐蚀状况的一种新方法,经过仿真和实验验证了伪随机码在管道检测中应用的可行性。     

基于多维关联规则和RFID的地铁施工实时动态监控研究

从地铁施工灾害风险源入手,采用多维关联规则数据挖掘方法甄选出关键警兆指标;EPC编码标签和监控看板对关键警兆指标信息进行标识;RFID射频识别技术实现信息的自动识别和远程监控.以期达到地铁施工现场各类分散风险信息的准确采集、实时监控和动态跟踪.     

ITU-T G.975.1中EFECI.7算法的研究与实现

光通信技术向着长距离、高速度的方向发展,具有更加强大纠错能力的EFEC算法正逐渐成为人们研究的热点.本文结合BCH码的特点,对EFEC算法1.7中描述的正交级联的BCH码的帧结构进行了研究,通过MATLAB编程实现了BCH码的编码以及基于BM算法的迭代译码,并分析了不同结构的BCH码的误码性能.实验结果表明:在相同的误码信道中,1.7中介绍的基于正交级联的BCH码的帧结构相此普通的BCH码具有更加优秀的纠错能力.分析结果对进一步研究通信可靠性具有一定的参考价值.