Socio-demographic and built environment influences on the odds of being overweight or obese: The Atlanta experience

This paper explores the association of socio-demographic and built environment characteristics on the odds of being overweight and obese using data from the Atlanta SMARTRAQ travel survey. A new methodological framework based on a multinomial logit (MNL) model and an enhanced odds ratio plot is presented. The use of an MNL model overcomes limitations of many prior studies that employ a sequence of binary logit models to examine multiple weight categories. The use of an enhanced odds ratio plot provides important information into the relative importance of socio-demographic and built environment characteristics. Several new findings for the Atlanta area result from this study. Socio-demographic variables, including age and educational attainment, exhibit a non-linear relationship with the odds of being overweight or obese. Gender, age, ethnicity, and educational attainment are strongly associated with the odds of being overweight or obese, while income and number of students between 5 and 16 years old in the household have smaller effects. Built environment characteristics such as increased net residential densities and enhanced street connectivity are associated with reductions in the odds of being overweight and/or obese. Relative to socio-demographic variables, however, such built environment characteristics have a much smaller impact on describing the odds of being overweight or obese.     

基于LabVIEW的机舱自动化系统设计

重点研究基于LabVIEW的机舱监控系统设计的必要性、意义及其核心思想和实现过程。根据机舱自动化系统的要求,实现对船舶主机里的主机转速、滑油进机压力、冷却水出机温度、冷却水压力、主机滑油温度;发电机里的电压、电流、频率、功率、滑油进机压力、滑油温度、冷却水温度;离合器压力和油温,工作压力等船用设备的实时监控与报警、运行状态显示、历史数据与报警查询等。     

Assessing the CO2 impact of current and future rail track in the UK

This paper investigates the CO₂ impact of current and future UK rail track and estimates the material, process and transport emissions associated with construction, maintenance and end-of-life activities for designs at high and low traffic loads. Analysis shows that for current track configurations, track with concrete sleepers has the lowest CO₂ impact, followed by steel, hardwood and softwood. Several potential future rail track designs have been analysed including embedded rail and double and quadruple-headed rail. All future track designs have a lower impact than current designs, but this improvement is more marked at high traffic loads. Up to a 40% reduction in CO₂ impact could be achieved if the UK rail network was to move from conventional track design to a double-headed embedded rail design. Key levers for reducing the CO₂ impact of track are identified as service life extension, traffic load reduction and the selection of low impact track designs.     

深埋隧道施工组织及不良地质地段施工方法

结合某深埋隧道工程，分析了隧道工程的施工过程与方法；针对该隧道的不良地质情况，重点介绍了超前帷幕注浆的技术方案、注浆设计和注浆工艺。     

考虑稳健性的汽车结构耐撞性优化设计

本文中基于C-NCAP中40%重叠度的偏置碰撞工况对某轿车进行结构耐撞性优化。为提高输出响应的预测精度,使用基于粒子群算法优化的支持向量回归模型来拟合设计变量与输出响应之间的关系,并利用非支配排序多目标遗传算法Ⅱ获得该优化问题的Pareto前沿。在确定性优化的基础上,并考虑产品性能在不确定因素影响下的波动,对其进行稳健性优化设计。最后,对优化结果进行有限元仿真验证。结果表明:优化后,结构质量减轻,耐撞性能明显提升,同时保障了稳定的产品性能。     

厦门港口资源整合模式的探索

在分析厦门港口资源整合的背景及意义基础上,探讨了厦门港资源整合的成功经验,并对进一步推进厦门港港口资源整合提出针对性建议。     

TJ165架桥机机臂强度有限元计算

本文在详细地分析了TJ165铁路架桥机机臂的各种受力状况后,对机臂进行了强度有限元计算。结论是机臂的设计是合理的,安全度是有高度保证的。     

Comprehensive lateral driver model for critical maneuvering conditions

A new comprehensive driver model is presented for critical maneuvering conditions with more accurate dynamic control performance. In order to achieve a safe maneuvering mode, a new path planning scheme to maintain stability of the vehicle was designed. A new steering strategy, considering the errors of vehicle position and yaw angle between the real track and the planned path, was established to obtain the steering angle. Therefore, the vehicle can be adjusted to accurately follow the desired path with the driver model, and the stability of the vehicle and the smoothness of the steering angle input were comprehensively considered. Simulation results were used to validate the control performance in comparison with the optimal preview driver model proposed by Macadam.     

Parameter identification for a LuGre model based on steady-state tire conditions

The purpose of this study was to effectively identify parameters for a LuGre friction model based on experimental measures. In earlier work related to this study (Yang et al., 2009), which was based on the characters of polygonal wear (Sueoka and Ryu, 1997), we showed a frictional vibration model for a mass on a moving belt. This model reflected lateral vibrations caused by velocity and toe-in angle. An important aspect of the present study is the improved friction model. A previous friction model, which divided the process into four parts, expressed the sable excited vibration well but failed to reflect the hysteresis loop change when vehicles accelerated or decelerated continuously. A LuGre friction model can solve this problem, but several model parameters must be obtained experimentally. We measured contact width and length of tires as vertical pressure changed; this provided a theoretical basis for apparent stiffness of a unit of tire tread. Based on tire data from Bakker E’s article in a SAE paper from 1987, we identified the Stribeck exponent and Stribeck velocity in LuGre. Then, the results were implemented in a vibration system that verified the rationality of the data.     

无锡金匮桥主桥钢箱梁设计

介绍了无锡金匮桥主桁结构设计、桥面系设计、非机动车道及人行道设计、静力分析及主要施工方法;为解决非机动车道与机动车道纵坡不一致的问题创造性地提出了采用调整托架的高度方法,事实证明在该桥上的应用是成功的;对该桥进行了详细的静力分析和稳定计算,计算表明,大桥各构件受力性能满足要求,大桥具有较好的稳定性。