便携式地空导弹脱靶量仿真研究

为了能够快速计算便携式地空导弹脱靶量,对导弹作战能力做一个初步判断,本文建立了便携式地空导弹脱靶量计算模型,并运用Simulink软件对其进行了仿真编程。编程所得Simulink模块可以清晰显示导弹与目标运动图形,并且得出弹目交会时弹脱靶量大小,为初步评价武器系统作战效能提供依据。     

数字方位仪设计与实现

根据实际需求,设计了一种新型的数字方位仪,并详细地介绍了数字方位仪的原理、硬件设计、软件设计和使用安装方法。     

浅谈集装箱装卸设备绿色节能设计

水路运输的迅猛发展,对集装箱装卸设备的技术创新提出了越来越高的要求。分别阐述了集装箱装卸设备进行绿色设计、节能改造和智能化设计的一些做法和成果。可以为集装箱装卸设备设计、购买和改造提供参考。     

天津城市立交车辆进出匝道的行驶状况

司机驾车在立交行驶远比在道路路段行驶复杂许多,甚至会对心理、生理造成较大的影响.尤其是司机驾车出入匝道的行驶状况,不仪对主线交通造成影响,甚至会造成交通安全事故.该文结合天津立交的实际,特对司机驾车进出匝道行驶状况进行测定,为今后的匝道设计、交通管理提供分析参考.     

中小跨径混凝土桥梁结构优化

针对公路高架桥上部结构常用的结构形式,选择墩梁连接方式、温度梯度、桥墩高度等参数进行了平面有限元静力分析,得出了一些优化建议。     

基于成本迭代与需求迭代的四阶段交通模型双重反馈算法研究

四阶段交通模型作为最流行的交通需求预测模型理论,其计算结果存在不一致性的缺陷,反馈算法被引入模型结构中来解决不一致性的问题。研究提出了成本迭代与需求迭代的双重迭代反馈算法,并使用案例比较了它与既有反馈算法的差异。研究结果表明：成本迭代＋需求迭代的双重迭代模型结构能够在不影响预测结果的前提下减少迭代次数和系统运行时间,收敛过程更加稳定且能够适用于不同规格的交通网络。     

高桩承台大体积混凝土裂缝控制探讨

文章结合厦门港海沧港区12#泊位液体化工码头工程实例,通过理论计算,研究在不同施工条件下,温度应力的数值和分布位置,从而科学指导确定施工中的底膜厚度和选择合适的配筋率;对于类似高桩墩式结构承台裂缝控制具有借鉴意义。     

Incentive subsidy scheme design with elastic transport demand

Huge public transport subsidies caused by deficits have become a heavy financial burden on some local governments due to the decline of bus passenger numbers. It is essential to apply the performance‐based contract to bus services considering maximization of social welfare. This paper constructs an incentive subsidy contract considering the decision‐making powers of the service level and calculating the proper frequency elasticity aiming at two problems of performance‐based contracts. Meanwhile, we consider a role of bus operators ignored by most researchers. Under the scheme, the decision‐making power of the service level is discussed based on five assumptions, and meanwhile, bus operators are motivated to reduce cost and improve service level in the scheme. The case of the bus service of Arao city indicates that the optimal frequency equals to zero when bus operators decide frequency. If bus operators determine efforts, the optimal effort also equals to zero with the goal of maximizing the profit. Also, bus operators can play their roles in lessening cost and improving service level to help bus operators and the local government achieve a win‐win situation, which maximizes the social benefit in this subsidy scheme when all factors are decided by the government. Copyright © 2013 John Wiley & Sons, Ltd.     

轮对安装偏角对高速铁道车辆动力学性能的影响

为了考察轮对初始安装偏角对高速铁道车辆动力学性能的影响,本文先从理论上分析了初始安装偏角下轮对的受力情况以及安装偏角对轮对行进过程所产生的影响,并通过多刚体动力学分析软件SIMPACK建立了我国高速铁道车辆的动力学模型,分别对车辆第一位轮在不同安装偏下的直线和曲线通过情况进行了仿真研究,研究表明：第一位轮对的初始安装偏角将使车辆的第一和第二位轮对的平衡位置偏离轨道中心线,且发生反向偏转,降低行车安全性;小偏角对平稳性影响不大,但偏角超过1 mrad后将对平稳性造成较大影响;安装偏角将对车辆曲线通过性能造成一定的负面影响,且影响随偏角的增大而增大,因此对于高速列车还应尽量减小轮对的初始安装偏角,尽量将其控制在1 mrad以内。     

Adaptive robust sliding mode control for ship straight-line tracking in random waves

Since complex controllers do not suit for application,we design a simple controller with robustness in changeable sea state.The characteristics of ship motion are large inertia,strong nonlinearity and large time delay.This paper employs adaptive sliding mode technique.We focus on a class of underactuated ship systems with parametric uncertainties and wave efects.Random wave efects are seldom considered in former studies.Various simulations validate the adaptive characteristics and robustness of the proposed controller.The closed-loop system is stable and tracking error can be arbitrarily small by Lyapunov approach.