Differences in cause-specific patterns of unintentional injury mortality among 15-44-year-olds in income-based country groups

OBJECTIVES: The aim of the present study was to investigate the cause-specific patterns of unintentional injury mortality among 15-44-year-olds in various income-based country groups, and to analyze which specific causes contribute the most to the unintentional injury mortality in each country group. MATERIALS AND METHODS: Cross-sectional data on the five most common causes of unintentional injury mortality by age-sex specific subgroups were compiled for 57 countries from the World Health Statistics Annuals for the year 1993 (1991-1994 if information for 1993 was unavailable). Data were categorized into four income-based country groups according to their gross national product (GNP) per capita for the year 1993. The differences between means and rate ratios of low, lower-middle, and upper-middle income countries were calculated by comparing them with those of the high-income countries. Regression analysis was performed to determine the trends in the direction of income for each specific cause of unintentional injury mortality by age-sex. RESULTS: For any of the specific causes of unintentional injury mortality there was an inverse relationship between mortality rates and GNP per capita except for motor vehicle traffic (MVT) among the 15-24-year-old age group. MVT accidents were the most common cause and contributed 26-77% of all unintentional injury mortality. The second most common cause was poisoning in all country groups except low-income countries where drowning dominated for males and mixed causes for females. Upper-middle income countries represented the highest MVT mortality in all age-sex subgroups except among 15-24-year-old females for which high-income countries displayed the highest rate. For other causes, lower-middle income represented the highest rates with a few exceptions. In the 15-24-year age group, the rate ratio of motor vehicle traffic mortality was higher in high-income countries compared to low-income countries, while in the 35-44-year age group, all other country groups showed a higher rate ratio than high-income countries. Drowning for males and burns for females in the low and middle-income countries were significantly higher than in high-income countries.     

CONSTRAINING HEAT INPUT BY TRAJECTORY OPTIMIZATION FOR MINIMUM‐FUEL HYPERSONIC CRUISE

Unsteady heat input effects are considered for the range cruise of a future hypersonic vehicle equipped with a turbo/ram jet engines combination. A realistic mathematical model for describing the unsteady heat effects has been developed. It is coupled to the model for the dynamics of the vehicle. To compute the heat load in hypersonic flight, several points on the vehicle surface are treated simultaneously. A two‐step technique consisting of an efficient optimization algorithm and an ordinary differential equations (ODE) solver is applied to generate a solution. The results show that the heat load can be significantly reduced, with only a small increase in fuel consumption.     

无人机操纵模拟训练中的VR技术

本文介绍了VR技术的基本概念,阐述了虚拟现实技术的核心思想,给出了用虚拟现实技术创建无人机操纵模拟训练系统的基本方法,具体说明了其中系统的整体构成,最后给出了系统将来的扩展情况.     

基于CAN／LIN总线的汽车通信网络设计

随着人们对汽车各方面要求的不断提高，汽车上的电控系统数量越来越多，随之产生诸如电路复杂性增加、可靠性下降、生产成本增加等问题。为解决上述问题文中提出了一种基于CAN总线和LIN总线技术的现代汽车通信网络的低成本设计方案。设计中将CAN总线技术用于高速的驱动系统中，将LIN总线技术（其节点成本是CAN的1／3～1／2）用于低速的车身系统中，在器件选型上采用了PHILIPS和FREESCALE的典型汽车电子芯片，既实现了应有的网络控制功能，同时也降低了车辆电子系统的开发、生产和服务成本，具有较高的实用性。     

主动轮廓模型在车牌识别算法中的应用研究

提出了一种识别机动车辆牌照的算法。该算法首先利用车牌的纹理特征和区域形状特征检测车牌区域。为提高区域检测的正确性，利用新的改进的主动轮廓模型，利用先验知识确定精确的车牌边界。在精确确定车牌区域基础上，可以准确切割出车牌中的字符，从而提高识别率。     

基于CAN总线的车流检测系统

介绍了一种车流检测系统的硬件、软件设计和实现过程。该系统采用热释电红外传感器检测是否有车辆通过，以AT89C51单片机为核心对传感器信号进行计数，同时控制CAN总线控制器构成CAN总线通信系统进行数据传输，从而实现了多车道、多路口的车流统计和监控。该系统可靠性高，监控范围广，成本低廉。     

基于整车配送的多仓库开路VRPTW问题的研究与实现

以整车销售物流为背景，探讨多仓库带时窗约束的车辆路线安排问题的解决方法．提出了更为复杂的基于现实的细节性要求的多配送中心开路VRPTW问题模型，并将遗传算法产生部分解和评估完整解的优化解决方法和涌现交叉算子MX1引入到带时窗的多仓库VRP问题优化中，实现了快速全局优化．提出的开路混合配送方法有利于提高车辆满载率，降低回程空载率．同时实现了运输资源的优化配置，提高车辆利用率．计算机仿真实验证明了算法的可行性．     

基于整数规划的多UCAV任务分配问题研究

在深入分析多UCAV任务分配问题的特点的基础上，提出了求解多UCAV协同任务分配的整数规划方法．通过设计决策变量和灵活地对各种约束条件形式化，建立了多UCAV任务分配问题的形式化模型．并以典型的UCAV任务SEAD为想定，进行了仿真验证与分析．仿真结果表明该模型可以较好地解决多UCAV协同作战的任务分配问题．     

应用ADAMS/CAR二次开发模块研究汽车操纵稳定性

为了实现汽车产品的虚拟开发,利用ADAMS/CAR二次开发模块建立了国产某小客车的整车多体系统动力学仿真模型。按照国家相关整车操纵稳定性的试验评价方法和标准,重复进行了整车稳态、转向回正等几种典型工况的仿真试验与分析。对比实车试验测试结果,主要参数项的最大仿真误差均控制在10%以内。对于实车试验测试和仿真试验测试结果均不理想的性能指标,经过参数调整可以得到比较理想的仿真结果。     

2005：乘用车需求有所回升 车价继续下跌

总结了2004年乘用车市场供求及价格状况。对2005年乘用车市场供求形势及价格走势进行了预测，指出2005年销量增幅有所回升，但供大于求的态势仍将保持，乘用车市场整体价格将继续下降，但降幅较2004年会有所减少。针对预测状况，对我国乘用车产业的发展提出政策建议。