Numerical Analysis of Particle Dispersion Characteristics at the Near Region of Vehicles in a Residential Underground Parking Lot

The study analyzed the transient air flow and particle dispersion at the near region of vehicles under idling conditions in an underground parking lot. It was found that the exhaust jet and particle dispersion behind the vehicles could be treated as a “nearly static” process from 20 seconds after the vehicle started. During the nearly static process, the particle dispersion behind the vehicle could be simplified to be exponentially upward. The particle concentration decreased logarithmically after 0.5 m behind the vehicle. The curvature of the particle streamline behind the vehicle under high exhaust temperature conditions is larger compared with that under low exhaust temperature conditions. When the vehicle exhaust temperature is high enough (318 K or higher in the study), the relationship between time and particle concentration above 3 m remains constant.     

Parking buses in a depot with stochastic arrival times

Given buses of different types arriving at a depot during the evening, the bus parking problem consists of assigning these buses to parking slots in such a way that they can be dispatched adequately to the next morning routes without moving them between their arrivals and departures. In practice, the bus arrival times deviate stochastically from the planned schedule. In this paper, we introduce for this problem two solution approaches that produce solutions which are robust to variations in the arrival times. The first approach considers that each arrival can deviate from its planned arrival order (sooner or later) by at most k positions, where k is a predefined parameter. In the second approach, the objective aims at minimizing the expectation of a function positively correlated with the number of buses that make the planned solution infeasible because they arrive too late or too early. In both approaches, the problem is modeled as an integer linear program that can be solved by a commercial mip solver. Computational results obtained on instances derived from a real-world dataset are reported.     

婴幼儿营养方便食品的研制

本文初步探讨了婴幼儿的营养特点，并分析了的婴幼儿的摄食特点，在此基础上结合国外部分婴儿食品的设计思路，充分开发利用我区优质的肉、奶、水果、蔬菜资源，针对性地开发研制了4种符合婴幼儿生理需要，并易于消化吸收的婴幼儿断奶食品或辅助食品。     

基于物联网技术的小区智能停车系统设计

根据小区对智能化停车的需要,设计了一种基于物联网技术的小区智能停车管理系统,能够实现车辆识别、车位预约、停车引导等功能。该系统以无线传感网、RFID、2．5G/3G通信为核心,通过射频识别技术（RFID）完成车辆信息识别,通过分布无线传感节点组成无线传感网完成模块间信息传输。实践证明：本系统可以有效地对小区车位进行智能管理,大大提高了小区物业部门的管理水平和工作效率。     

地磁车辆检测器抗邻车位干扰的磁场角度关系分析应用

利用地磁车检器进行停车位检测时,车检器检测轴方向、停车位方向以及地磁场方向之间的角度关系,影响车检器不同轴向的峰值与灵敏度,随意设置会产生邻车位干扰或对磁场扰动的灵敏度低等问题。本研究基于双轴向地磁车检器,在不同停车位方向下,对车检器各个轴向进行测试,找出的最佳指向在保证正向轴高峰值高灵敏度的同时,使侧向轴低峰值低灵敏度,在提高检测精度的同时,减少邻车位干扰问题。研究给出了经验公式,在各地实践中,均得到了良好的效果。     

磁助器在准分子激光器中的应用

介绍磁助器的设计原则和方法，并成功地应用于准分子激光放电电路中，实验结果表明，设计的磁助器能在不显著影响激光输出能量情况下，减少高压快放电中开关器件─—闸流管的能量损耗，减小反向电流。     

基于Web的智能停车诱导系统的方案设计

经过对停车诱导系统现状的研究,结合智能交通系统,设计了一个功能全面的智能停车诱导系统。系统采用分区诱导的策略,主要功能模块包括停车场数据采集、停车场数据处理与分析、管理中心数据发布及停车场数据接收等几个模块。采用比较流行的B/S模式对智能停车诱导系统进行管理,课题研究重点为车载诱导终端及停车场内停车诱导。     

Low-thrust trajectory optimization in a full ephemeris model

The low-thrust trajectory optimization with complicated constraints must be considered in practical engineering. In most literature, this problem is simplified into a two-body model in which the spacecraft is subject to the gravitational force at the center of mass and the spacecraft＇s own electric propulsion only, and the gravity assist （GA） is modeled as an instantaneous velocity increment. This paper presents a method to solve the fuel-optimal problem of low-thrust trajectory with complicated constraints in a full ephemeris model, which is closer to practical engineering conditions. First, it introduces various perturbations, including a third body＇s gravity, the nonspherical perturbation and the solar radiation pressure in a dynamic equation. Second, it builds two types of equivalent inner constraints to describe the GA. At the same time, the present paper applies a series of techniques, such as a homotopic approach, to enhance the possibility of convergence of the global optimal solution.     

多目的地多停车场系统动态停车分配模型

在一个多目的地多停车场系统中,每个目的地附近有多个停车场可供选择,每个停车场也可供多个目的地的停车需求停车。每个目的地的停车需求在各停车场的停车量即为停车分配问题. 本文定义了停车量分配均衡原则:各目的地的驾驶员总是首选最低费用(包括在停车场内的停车费用以及停车时间、步行时间转换后的货币成本,其中停车费用及在停车场内的车位找寻时间都正相关于该停车场当前时刻停车饱和度)的停车场停车;由于停车场具有容量限制,当费用最低的停车场已满则再选择费用次低的停车场,以此类推;所有没被使用的停车场或者比被使用的停车场具有更高的费用或者停车位已满。考虑停车需求和各停车场内空余泊位数的实时动态特性,提出了与该均衡原则等价的数学规划模型,证明了其解的唯一性并设计了求解算法。通过两个算例对模型进行了验证,并再现了目的地附近各停车场内车位占用变化规律,从而为动态停车收费、停车选址规划等提供依据。     

半超结VDMOS的研究

为了改善功率器件导通电阻与击穿电压的折中关系,提出了半超结理论及其设计方法.在原胞部分研究了各个器件结构参数的深度和浓度的优化,在终端部分提出了一种平面结终端技术;提出了实现半超结VDMOS的工艺实现方法,并利用2-D仿真软件Medici进行仿真验证.结果表明,利用该优化方案,可以得到特征导通电阻为40 mΩ·cm2的600 V半超结VDMOS器件.