基于CAN总线的船舶声纳数据采集系统分析

声纳上传的数据需要高速的具有合适采集频率的数据采集系统才能够实现对船舶声纳数据的提取和分析,文章设计了基于CAN总线的声纳数据采集系统,完整的给出了数据采集系统的总体结构和采集节点的硬件构成,在此基础上重点分析了数据采集系统采样频率和CAN总线接口电路的设计,对于船舶声纳数据采集系统的研究具有一定的借鉴意义。     

基于最大匹配法的中文分词技术改进

在简介最大匹配法(MM)分词算法的基础上,指出了MM算法存在的不足,分析了MM改进分词算法的需求及过程设计,研究了MM改进分词算法以及过程处理原则,研究了改进算法过程中的歧义检测与切分、未登录词识别等问题,提出了消除策略和处理原则.     

快速测定铝／氧化银电池电解液中碱浓度的方法

用传统化学分析方法测量铝／氧化银电池电解质溶液组分浓度耗时长。针对这一弊端,本文提出通过测量电解质溶液密度、温度,然后结合计算出的铝酸盐浓度,再对照在不同温度下电解质溶液密度与铝酸盐浓度关系曲线图,快速确定电解质溶液中碱的浓度的方法。在电池实际放电过程中证明该方法行之有效。     

竖向接缝对连续刚构桥长期变形的影响分析

结合施工因素讨论连续刚构桥竖向接缝对成桥后期挠度的影响,同时分析不同施工质量下竖向接缝剪切徐变对后期挠度的贡献．对提高接缝质量具有重要意义。     

Mechanism of Tunnel Water Inflow Caused by Bending Failure of a Waterproof Dike Based on a Circular Thin Plate Mechanical Model北大核心CSCD

Water bursts during tunnel construction endanger construction, and it is therefore necessary to reserve a waterproof dike with the required thickness to avoid water bursts and to take reinforcement of the dike and treatment of the structure liable to trigger a water burst. Using the water burst at K5+398 of the Mingyueshan tunnel of the Shanghai-Chengdu expressway as an example, and considering the type of tunnel section and the upright mudstone of the dike, the waterproof dike at the work face is simplified as a round thin plate. A formula for the calculation of a minimum safety thickness for the critical waterproof dike is deduced by analyzing the force applied on the water-proof dike, and the minimum safety thickness for the water burst section at K5+398 of the Mingyueshan tunnel is cal-culated. The numerical simulation analysis demonstrates the critical thickness of waterproof dike at K5+398 of the Mingyueshan tunnel is 1.4-1.55 m, and the calculated water inflow and water burst basically agree with the actual condition. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

Mathematically calculating the transit time of cargo through a liner shipping network with various trans-shipment policies

This paper derives the mathematical expressions for the transit time of cargo through a liner shipping network. Main efforts are devoted to deriving the calculation expressions of the connection time of cargo during trans-shipment. For the forward and many-to-one trans-shipment policies, we conduct a minor correction towards the expressions in existing studies to improve the completeness. Meanwhile, we propose an alternative but more straightforward calculation method for connection time which bypasses the complicated inductive argument in existing studies. Then we introduce two new trans-shipment policies: backward trans-shipment and one-to-many trans-shipment, and mathematically calculate the corresponding connection times. Numerical experiments also deliver some managerial insights into the effectiveness of backward trans-shipment in transit time control.     

城市道路双层隧道交通监控系统设计探讨

本文介绍了城市道路双层隧道交通组织方案和交通诱导方案,分析了双层隧道与单层隧道的区别,阐明了双层隧道交通监控系统的特点。提出了双层隧道不同交通组织情况下的交通监控方案、现场控制网络设计要点、视频监控系统优化方案以及交通安全和设施安全方面需要考虑的问题,可作为同类工程监控方案设计的参考。     

基于遗传算法的BP神经网络短时交通流预测

对BP神经网络模型、方法及遗传算法的基本原理进行了分析,将遗传算法与标准BP神经网络算法相结合构建了基于遗传算法的神经网络算法;建立了基于BP神经网络的短时交通流预测模型,对BP神经网络算法及基于遗传算法的BP神经网络算法进行设计,并将其应用于短时交通流预测模型的仿真计算,仿真结果表明基于遗传算法的BP神经网络算法具有更快的计算速度及更好的适应能力,该方法可以较好地应用于短时交通流预测。     

不同驾驶操作行为对车辆燃油消耗量的影响分析

针对车辆驾驶员普遍存在盲目换挡、急加速等不良驾驶行为的现象,研究采用发动机台架试验和道路试验相结合的方法,对汽车起步、换挡时机的选择、加速、减速、车速控制等典型的驾驶操作行为展开研究,通过对不同驾驶操作行为燃油消耗的分析,规范了汽车驾驶操作行为。     

“天鲲”号超大型自航绞吸挖泥船总体设计技术

结合国内外超大型绞吸挖泥船的特点和发展趋势,对我国自主研发设计的"天鲲"号超大型自航绞吸挖泥船的船型、主尺度和总布置等总体设计要点进行详细论述,形成了大型绞吸式挖泥船船型论证分析的总体思路,为超大型自航绞吸式挖泥船的总体设计提供参考,提升了国内整体绞吸船的设计和建造水平。