用数控电子——液压振动台

本文简述运输环境和试验条件的制订对模拟运输试验的各种方法作了简单评述,尤其是对利用电子－－液压振动台对大型整体产品在悬臂梁状态的试验作了介绍。最后说明一种能模拟带有高峰值随机振动的试验技术,以改进现有数控设备的不足。     

水质管理规划中BOD5响应矩阵的一种改型模式

本文推导对水质管理规划中经典BOD5响应矩阵的一种改型模式,并对数值例加以阐述.该模式以BOD5总量为控制对象,任一河流断面的BOD5输入量在此响应矩阵中仅出现一次,从而使响应关系由下三角矩阵改变为每一行均含三个变量的稀疏矩阵。这一改型不仅提高了计算速度,更重要的是,由于改型模式具有运输问题类型良好的特殊结构,可以方便地判断一个水质管理规划问题是否可行和给出可行的充分必要条件,这一特性具有较大的实际经济意义.改型模式与经典模式所需数据完全相同。      

Regional economic conditions and crash fatality rates--a cross-county analysis

INTRODUCTION: Most studies that evaluate the relationship between economic conditions and traffic fatalities focus on the time-series relationship between the two factors. This analysis considers the cross-sectional perspective by estimating the cross-county correlation between per capita income and fatalities per vehicle mile traveled (VMT) in Ohio. METHOD: The empirical model employed in this analysis allows for interaction effects between per capita income and highway usage, in the determination of fatality rates. RESULTS: The resultant least squares estimates indicate that a significant interaction effect exists between per capita income and the percentage of highway VMT, indicating a nonlinear correlation between per capita income and fatality rates. This correlation rises as the proportion of VMT on highways rises, such that there is an inverse relationship with fatality rates when the highway share of county VMT is low and a direct relationship with fatality rates when the highway share of county VMT is high. Additionally, population density, the presence of interstate highways in rural counties, the prior prevalence of severe alcohol abuse, and the proportion of teen drivers all proved to be significant correlates with county fatality rates. CONCLUSIONS: These observations suggest factors that state and federal policy makers should consider when allocating resources that impact (whether directly or indirectly) traffic fatalities.     

How does the presence of HOV lanes affect plug-in electric vehicle adoption in California? A generalized propensity score approach

Policymakers have sought to spur consumer adoption of advanced clean vehicles by granting them single-occupancy access to high-occupancy vehicle (HOV) lanes. We offer the first evaluation of these policies that accommodates geographic variability in the magnitude of this policy's treatment effect. Focusing on the outcome of plug-in electric vehicle (PEV) adoption in California, we employ a generalized propensity score approach that allows for continuous, rather than binary, treatment effects. We estimate a state-wide dose-response curve to show that access to 6, 20, and 100 miles of nearby HOV lanes leads to 1, 3, and 10 additional PEV registrations in a census tract. The lower end of our 95% confidence interval implies that at least one quarter of California PEV registrations during 2010–2013 were a result of the HOV lane policy. We identify geographically-specific marginal policy effects that are smaller in Los Angeles, but relatively larger in San Diego and Sacramento.     

吸收法和吸附法油气回收技术的联合应用

介绍了吸收法、吸附法、冷凝法及膜法回收轻质油品蒸发排放出来的油气的回收机理和关键工艺设计数据，分析了在工程应用时存在的一些关键问题、回收效果影响因素。综合比较工业应用时的优缺点和适用范围，认为常压常温吸收法和活性炭吸附法回收技术可在工业实践中联合运用。应用油气回收装置将带来明显的社会效益、环境效益及经济效益。     

Switching to alternative transit: combining bicycle safety improvements with parking regulations

Smart growth policies advocate for economically viable, environmentally conscientious, and socially equitable solutions for urban development. These policies were developed largely in response to issues rooted in the automobile-oriented culture: air pollution, high greenhouse gas emissions, traffic congestion, and sedentary lifestyles. In urban settings, a good transportation alternative is cycling, since it is able to serve the travel needs of nearly half of city dwellers’ daily trips. Many European and Canadian cities have successfully increased cycling rates by creating safer bicycle environments and restricting or discouraging automobile use. To evaluate the potential effects of the above measures on American urban areas, this paper examines case studies of cycle tracks and bicycle boulevards implemented in American cities, and how these facility improvements have changed how safe cyclists feel on the road and overall bicycle usage. Results show the two methods are indeed effective in increasing bicycle usage rates. Ultimately, increasing cycling rates needs policies to discourage people from driving, the greatest mode share in nearly all urban areas. Parking policy has major impacts on people’s decision to use the automobile. Currently, parking is oversupplied and underpriced in many cities, making it irresistible for people to drive. Decreasing the number of parking spaces available and increasing their price will increase pressure on drivers to drive less, especially for short trips, and to bike instead. It is important for planners and policy makers to realize that solutions from both directions, making biking more enjoyable and making parking, and hence driving, less affordable, should be used in tandem. The complementary nature of the two approaches makes it so the effect of the combination is greater than the sum of the two.     

Road safety in China: Analysis of current challenges

Introduction

China has the world's largest population, and is the second largest automobile market. China's economy is booming, resulting in a rapid increase in both the road infrastructure and access to private vehicles. Along with economic growth, the ownership of motorized vehicles has almost quadrupled in the past 10 years, from 42.2 million in 1997 to 159.7 million in 2007. However, at the same time, China also has a very high number of road fatalities compared to other countries, with about 100,000 reported fatalities each year.

Method

This study analyzes the Chinese road-fatality situation to identify areas in which the total harm caused by crashes can be substantially and readily reduced. It provides a comprehensive analysis of the current road-fatality situation in China using conventional indices and the likely future trends.

Results

Four areas were identified in which countermeasures have the most potential to substantially reduce fatalities in China: pedestrians and other non-motorists, nighttime driving, vehicle passengers, and motorcycles.

Conclusion

While China faces unprecedented road safety issues, this report identifies major areas in which there are opportunities to greatly reduce total harm.     

闽南地区酸沉降来源特征的模拟研究

设计了一个二维长距离硫传输Lagrangian模型,模拟了闽南地区酸沉降的来源特征?结果表明:闽南地区硫沉降中外来源与局地源的相对贡献存在着明显的季节变化;由年均贡献看,闽南地区硫沉降主要由外来源的长距离输送造成      

Inventory routing for dynamic waste collection

We consider the problem of collecting waste from sensor equipped underground containers. These sensors enable the use of a dynamic collection policy. The problem, which is known as a reverse inventory routing problem, involves decisions regarding routing and container selection. In more dense networks, the latter becomes more important. To cope with uncertainty in deposit volumes and with fluctuations due to daily and seasonal effects, we need an anticipatory policy that balances the workload over time. We propose a relatively simple heuristic consisting of several tunable parameters depending on the day of the week. We tune the parameters of this policy using optimal learning techniques combined with simulation. We illustrate our approach using a real life problem instance of a waste collection company, located in The Netherlands, and perform experiments on several other instances. For our case study, we show that costs savings up to 40% are possible by optimizing the parameters.