Solving Nonlinear Differential Equation Governing on the Rigid Beams on Viscoelastic Foundation by AGM

In the present paper a vibrational differential equation governing on a rigid beam on viscoelastic foundation has been investigated. The nonlinear differential equation governing on this vibrating syst...     

Factors Affecting Knowledge,Perceptions, and Attitudes Regarding North Carolina Coastal Reserve Management

During the period May 25–October 28, 2007, we collected data in face-to-face interviews on four sites in the North Carolina Research Reserve system. We subsequently conducted analyses on the effects of education, income, length of visitation, and frequency of visitation on visitor knowledge, perceptions, and attitudes regarding management. Visitors to the sites were well-educated, listed incomes above the state median, and were racially homogeneous. At the overall level, the majority (63%) knew who owned the sites, but only 43% correctly identified the managing agency. The majority also believed that overall conditions at the sites were stable, although those that had been visiting longer perceived conditions as deteriorating. Education was positively correlated with knowledge of ownership and management, and with support for additional rules and enforcement. Neither income, nor frequency of visitation showed any correlation with any of the dependent variables at the overall level. Some site-specific findings differed from the overall findings and varied from site to site. These differences were addressed individually.     

采用单电压源逆变器双异步电动机结构提高机车传动系统的性能

介绍了一种特殊的多电机多变流器系统(MMS)结构,即专为轨道牵引设计的单逆变器双电机结构.牵引设备必须具有良好的转矩响应,为了控制两台电动机的转矩,可以采用基于传统磁场定向控制(FOC)的协调控制结构.单逆变器双异步电动机传动系统可以提高机车性能,降低由内部和外部干扰产生的不良影响,对其系统性能与传统的机车传动控制系统的性能进行了比较.机车制造商已对仿真模型进行了确认.根据结果对这2种控制方式进行了性能分析,而且考虑了该牵引系统中的4种特性干扰.     

An application of the CUSUM algorithm to freeway incident detection based on two contiguous detectors

The CUSUM (cumulative sum of log‐likelihood ratio) algorithm is a detection algorithm that shows potential for the improvement of incident detection algorithms because it is designed to minimize the mean detect delay for a given false alarm constraint and it can also detect changes with different patterns. In this study, the CUSUM algorithm was applied to freeway incident detection by integrating traffic measurements from two contiguous loop detectors and the non‐stationarity of traffic flows. The developed algorithm was tested based on incident data from the PATH program, with consideration given to the impact of different geometric conditions on algorithm performance. It was also compared with two existing algorithms, in order to address the influence of traffic patterns. The evaluation results show that the CUSUM incident detection algorithm can perform equally well in comparison with the selected algorithms.     

Évaluation de mesures d’urgence potentielles en cas de pic de pollution atmosphérique en Alsace

Ten years after their implementation, the Alsatian prefectorial orders concerning emergency measures applied in case of exceedance of alert thresholds for ozone, nitrogen dioxide and, a pioneer feature of the French region, the PM, required an update. In 2007, the ASPA was mandated by the Bas-Rhin and the Haut-Rhin Prefectures to define and assess new emergency measures. The Alsatian emissions inventory first identified the activity sectors which would be potentially targeted by the measures, and then calculated the associated emission reductions. In association with the transportation agency, 3 scenarios were retained for concentration simulation: limitation of the speed limit at 70 km/h on freeways and major urban roads, alternated traffic in towns, and a combination of both measures. Then, an integrated modelling chain, including the CHIMERE and ADMS-Urban models, was allowed to simulate, for the three scenarios, the variation of ozone during the heat wave of 2003, and the variation of nitrogen dioxide and the PM during wintry episodes, for the cities of Strasbourg, Colmar and Mulhouse. Finally, the urban cartographies of the impact of the scenarios on the concentrations were crossed with the georeferenced residence data to estimate the population affected by threshold exceedances in each case. A weak impact was obtained for speed limit reduction, while it was significant for the alternated traffic; for the PM, the concentrations fell about 10 μg/m³ and the population exposed to threshold exceedance fell by a factor 4; for nitrogen dioxide, the concentrations were lowered by several dozen μg/m³ and the exposed population fell by a factor 2; whereas for ozone, we noted a slight increase in the concentration and the exposed population. At the same time as the implementation of the newly developed emergency measures, the evolution of knowledge and modelling shows that it would be technically justified to differentiate the measures, pollutant by pollutant.     

Exploring the distances people walk to access public transport

ABSTRACT

A shift from private motorised transport to more active transportation can, among other things, deliver significant health benefits. The main disadvantage of active transport (in particular walking) for most people compared to private motorised transport is the limited range. Public transport (PT) can complement the use of active modes and extend their range. Therefore, there might be potential to increase physical activity through an increase in PT use. This article takes a closer look at how walking relates to the use of PT by examining existing literature on the topic. It aims to study how far people walk to and from PT and what key factors influence this. Scopus, Transport Research International Documentation and Web of Science have been searched systematically for relevant articles, conference papers and books. After screening of titles and abstracts, 41 relevant publications were identified. Studies were included if they quantified the amount of walking (measured as either distance or time) that is directly related to the use of PT. Studies that quantified walking using general measures of daily physical activity or daily walking or that used stated preference designs were excluded. The PT systems considered in this paper are mass transport systems in urban areas, either road- or rail-based, with fixed schedules and stops. Demand responsive transport services, which can offer door-to-door travel, are not considered, as these systems can to a large extent eliminate the need to walk. In the identified publications, a large variety of walking distances and times have been reported, and these seem to be highly context-specific. The paper establishes the evidence for the wide range of factors that influence walking related to PT, which have been categorised as personal, PT-related, environmental, and journey-related. The different methods that have been used are discussed by critically analysing their advantages and limitations. Only a limited number of these methods used allow for an accurate assessment of the walking distances to and from PT. The paper concludes with suggestions for future research, such as a need for more accurate measurement of walking and research in different geographical areas to shed light on underlying influences of culture and climate.     

Addressing the joint occurrence of self-selection and simultaneity biases in the estimation of program effects based on cross-sectional observational surveys: case study of travel behavior effects in carsharing

Transportation - We estimate the effect of carsharing on travel behavior (specifically, household vehicle holdings, frequency of transit usage, and frequency of biking and walking) using data from...     

Representing heterogeneity in structural relationships among multiple choice variables using a latent segmentation approach

Transportation - Travel model systems often adopt a single decision structure that links several activity-travel choices together. The single decision structure is then used to predict...     

Integral Recrystallization Modelling

1.IntroductionAlthoughmancanproducemetallicmaterialssincemorethan5(X)0yearsitisafundamentalfindingofonlythiscenturythatthePropertiesofamaterialarenotdeterminedbyanymacroscopicquantity,likeoverallcomposition,dimensions,strainortemperature,ratherthanbyitsmicrostructure,i.e.thespatialdistributionofelements,phases,orientationsanddefects.Thismicrosmicture,however,isliabletOchangeduringprocessingofamaterialfromtheliquidstatetothefinalproduct,anditcanbesubstantiallyaffectedbychangingtheprocessingcon…