舰载火箭炮在登陆作战中的应用研究

舰载火箭炮射程远、射速快、火力猛,是水面舰艇对岸火力支援的利器,分析了登陆作战各阶段火力需求,研究了舰载火箭炮在登陆作战中的火力任务,论证了舰载火箭炮在登陆作战中的火力运用,为舰载火箭炮的作战运用提供了科学依据.     

船用空气压缩机故障诊断分析与试验研究

活塞式空气压缩机的主要功能由往复运动完成, 振动是其主要故障标志之一。针对往复式空气压缩机各部件运动引起的复合振动激励信号,对各部件建立振动信号模型并提取冲击响应信号特征,在时域与频域里进行综合分析,提取各故障特征参数和判据从而诊断压缩机常见故障。     

集对-层次耦合法在崩塌区危险性评价中的应用

有效预测崩塌灾害致灾区域及其危险性,为合理规划土地资源、实施崩塌防灾减灾提供重要指导借鉴。遴选斜坡坡形、坡度、坡高、下垫面岩土性质、落石质量、落石形状和落石的岩性条件等7个因子作为崩塌区域致灾危险性评价指标;通过指标量化,采用广义集对分析法和层次分析法相结合,确定了崩塌区域致灾危险性评价指标权重;采用同、异、反联系测度提出了落石停积在各承灾区的可能性评价模型,并根据落石停积位置的预期概率将崩塌致灾危险性分为极高危险、高危险、中危险、低危险和极低危险等5个危险性等级。最后通过现场落石试验,验证了危岩崩塌区域危险性广义集对-层次耦合评价方法的合理性     

基于ANSYS的几种不同消声器的数值仿真

设计了一种由旁支管和扩张式消声器组合而成的消声器,利用ANSYS的动力学及声学模块,对其进行模态分析和声学分析,得到该组合消声器的固有频率和消声插入损失曲线。对旁支管和扩张式消声器分别进行声学分析,得到它们的消声插入损失曲线。仿真分析发现:组合消声器在发动机基频排气噪声及低频谐次波处有很好的消声效果,与单独的旁支管和抗性消声器相比,其消声效果有明显提高,达到了设计要求。该仿真结果可用于预测消声器的性能,并判断其结构设计是否符合要求。     

基于滑移率的ABS粒子群优化PID仿真控制研究

通过对车辆制动过程的分析以及ABS工作原理的分析,在MATLAB/Simulink环境下,建立单车轮ABS仿真模型,并对基于滑移率为控制对象的常规PID控制的汽车ABS系统以及PSO优化PID控制的汽车ABS系统进行仿真与研究。研究和仿真表明,PSO优化PID控制的ABS系统与常规PID控制的ABS系统相比具有更好的滑移率效果和制动距离。运用模拟驾驶仪开展的仿真试验结果与理论分析相吻合。     

崩塌灾害危险性评价方法及应用

基于RocFall数值模拟软件,划定落石威胁范围。危岩的自稳能力和致灾能力是导致崩塌具有危险性的两个先决条件,据此遴选崩塌灾害危险性评价指标,通过计算各指标的灰色关联系数,进行相对重要性排序,结合层次-集对分析法求解评价指标的权重值,基于综合指标评价法建立崩塌灾害危险性评价方法,并根据最危险原则法将崩塌区分为极高危险、高危险、中危险和低危险4个等级。将此方法应用于巫山望霞危岩,评价得出望霞危岩属于高危险,与实际情况吻合良好。     

A new lost time estimation method for right‐turn traffic in Japan considering signal phasing and sneakers

Precise estimation of the capacity for right‐turn traffic (comparable to left‐turn traffic in the USA) is of great importance to determine signal phasing schemes at signalized intersections in Japan, where the left‐hand driving rule is valid. However, in most signal timing procedures across the world, the lost time of right‐turn traffic is simply determined by the duration of intergreen intervals and thus lacks considerations of various signal phasing and driver behavior. Meanwhile, sneakers per cycle are usually applied to account for the number of drivers completing right turns during the effective red portion of the clearance‐and‐change intervals. As a result, an initial cycle length must be hypothesized in order to assess the total number of sneakers within the analysis period. Consequently, a time‐consuming iterative calculation process often becomes necessary. Therefore, the present study aims to develop a new lost time estimation method for right‐turn traffic to overcome the aforementioned drawbacks. Lost times of right‐turn traffic under three conventional phasing plans are theoretically formulated on the basis of a time–space diagram and shock‐wave theory. The new method is validated using field data, with case studies of its application in the signal timing procedure. Results indicated that the proposed method is capable of offering more accurate estimation than conventional approaches, which leads to shorter cycle length and simplifies signal timing process by eliminating an iterative check to determine the number of sneakers. Copyright © 2012 John Wiley & Sons, Ltd.     

Relationships among service quality,corporate image,customer satisfaction,and behavioral intention for the elderly in high speed rail services

Since the Taiwan High Speed Rail operations, Taiwan's transportation market entered into a new era. Because of its competitive service of speed, convenience, environmental concerns and comfort, the High Speed Rail has not only made significant changes but has played a significant role in Taiwan's transportation. However, Taiwan now is an aging society. Due to the physical constraints among the elderly, demands to redesign the traffic system and maintain transportation safety are essential considerations. In the current market, Taiwan's transportation construction is facing fewer barriers; however, it must still improve, especially considering the health of the elderly. Thus, this study investigates elderly passengers' demands and further examined the relationships among service quality, corporate image, customer satisfaction, and behavioral intention. According to empirical analytical results based on structural equation modeling (N = 341), satisfaction directly affected travel behaviors, while service quality and corporate image played indirect roles. In addition, service quality plays a significant role on the effect of satisfaction. This study provides empirical evidence to indicate the quality of the accessible environment affects not only the effectiveness and efficiency of service quality, but also, the corporate image. The results provide valuable references for critically managing the elderly's usage of the high speed rail transportation service. Copyright © 2011 John Wiley & Sons, Ltd.     

Short-term work team scheduling models for effective road repair and management

Abstract

In this study, we focus on the development of work team routing/scheduling models incorporating stochastic travel and repair times. Robust and expected optimization concepts, combined with a time–space network technique, are used to develop the models. We perform numerical tests based on operational data for Taoyuan County in Taiwan. The test results show the good performance of the models.     

西安地铁四号线沿线地裂缝活动趋势预测及危险性评价

西安地铁四号线是西安市轨道交通线网中的十字骨架,是线网中的骨干线路,它穿越了14条活动的地裂缝带.为进一步研究西安地裂缝,给地铁线路沿线地裂缝的防灾减灾提供科学依据,本文通过野外地质环境和地质灾害调查,着重查明了西安地铁四号线沿线的14条地裂缝的发育特征;并根据近些年的监测成果资料对地裂缝的活动性进行了分析总结,预测了其活动趋势;采用定量计算的方法确定了地裂缝对地铁线路的影响范围,并在综合分析地铁线路危害特点的基础上确定了地裂缝与线路相交段的危险性等级,最终将与地铁四号线相交的地裂缝划分为Ⅰ级、Ⅱ级、Ⅲ级三个等级.地裂缝灾害是西安主要的地质灾害,在地铁建设中要给予高度重视.