包头西车辆段检修工艺改造设计

结合既有车辆段改扩建设计的特殊性,详细论述了工艺改造设计过程中的工程特点、能力适应情况、检修工艺布置等技术环节的原则和特点,为后续设计提供了参考和依据。     

干道协调控制相位差模型及其优化方法

通过对协调控制系统进行相位优化设计,综合考虑各路段的平均车速、车流的离散性、相交道路的转弯车流以及车辆到达的不均匀性等各种影响干道协调控制方案实施效果的主要因素后,建立了一种新的干道协调控制相位差模型.以干道控制系统的总延误与总停车次数作为相位差模型的输出,对上、下行车队在交叉口的延误规律进行了分析,并利用Matlab编程计算来实现相位差的优化.结果表明:该优化模型为解决干道协调控制相位差优化问题提供了一种新方法.     

New applications of EXIT chart for iterative decoding systems

Applications on iterative control and multiple input multiple output （MIMO） system were developed. Two new charts derived from extrinsic information transfer （EXIT） chart were employed as the designing tools, which are called as output mutual information chart with defined iterative degree （DID） chart and near optimum output mutual information （NOMI） chart respectively. Different from the EXIT chart, they can show the iterative performance on the whole signal-to-noise ratio range with one single curve, whereas computation complexity is greatly reduced compared with conventional bit error ratio （BER） performance curve. The iterative control was implemented according to a near-optimum iterative degree vector determined by NOMI chart, the reasonability of uncertain parameters was analyzed in one MIMO system. The concepts were illustrated based on bit-interleaved coded modulation with iterative decoding （BICM-ID）.     

Eco-design of transportation in sustainable supply chain management: A DEA-like method

This study addresses the issue of eco-design for transportation in sustainable supply chain management (SSCM). Data envelopment analysis (DEA) is adopted and extended to construct a model for this application. This proposed model, together with the tractable algorithm developed in this research, can provide stakeholders with a Pareto Optimal transportation strategy. This derived transportation strategy can help stakeholders realize certain transportation goals with less resource consumption and pollution emission. The discussion presented leads to a heuristic Joint Transportation Policy and concludes with two useful suggestions for putting the strategy into practice. The proposed model was used in an empirical study of design sustainable transportation mechanism for one air-condition manufacturer in China to transport its products as well, the analysis further demonstrating the theoretical and practical value of this research.     

应用Excel绘制试验图表

结合实例,介绍Excel在试验中的应用情况,说明应用Excel绘制试验图表,要透彻分析试验规程中数据计算的要求,才能保证结果的高精度。     

地铁运行图质量指标评价研究

通过对地铁运行图质量指标体系的研究分析,以广州地铁为例,阐述了三大指标对列车运行图的评价意义,期望给同行提供借鉴.     

墨卡托海图特性分析

墨卡托海图占目前航用海图的95%以上,在航海中起着重要的作用。本文从墨卡托投影的数学原理出发,借助地图学投影的知识,推导了墨卡托投影的公式和变形。在此基础上,进一步讨论了墨卡托投影的主要特性和墨卡托海图的特征及用途。     

基于GMDSS的电子海图定位仿真研究

通过墨卡托投影,将船舶所处位置地理坐标转换平面坐标,再由平面坐标转换为屏幕坐标,同时将海图按Inmarsat系统作用区域进行划分,推导出每块区域边缘曲线公式,从而可以判断出该船所在的洋区以及与卫星之间的距离,以选择对应卫星进行通信.经测试,上述算法可准确满足GMDSS的需求,可方便的得以使用.     

基于DGPS、AIS、GPRS的船舶导航与监控系统

为了保障海上人命安全,特别是在能见度不良情况下有效地保障船舶航行安全,综合应用高精度差分GPS定位技术、GPRS数据传输等技术实现了船舶导航与监控系统。该系统具有形势监控、本船监控、他船监控等功能。     

不同方法对南黄海重现波高计算值的影响

采用SWAN波浪模型对江苏南黄海地区1979~2018年共40 a的波况进行模拟及验证,将模拟结果与实测资料进行比对,吻合良好。百年重现波高分布通过基于年极值和月极值的广义极值分布函数(GEV)和超阈值取值方法(POT)的广义帕累托分布模型(GP)计算得出。计算结果表明,不同方法的计算结果在辐射沙洲北部地区差别最大,采用月极值所得重现波高偏小,采用年极值计算的重现波高在辐射沙洲南北外围地区最大,其余地区则以POT方法为大值。在分别采用不同数据长度计算重现波高的试验中得出,取月极值的GEV分布计算结果对时间跨度的改变不敏感,而取年极值受之影响最大,POT方法介于两者之间。