Modelling shared space users via rule-based social force model

The promotion of space sharing in order to raise the quality of community living and safety of street surroundings is increasingly accepted feature of modern urban design. In this context, the development of a shared space simulation tool is essential in helping determine whether particular shared space schemes are suitable alternatives to traditional street layouts. A simulation tool that enables urban designers to visualise pedestrians and cars trajectories, extract flow and density relation in a new shared space design, achieve solutions for optimal design features before implementation, and help getting the design closer to the system optimal. This paper presents a three-layered microscopic mathematical model which is capable of representing the behaviour of pedestrians and vehicles in shared space layouts and it is implemented in a traffic simulation tool. The top layer calculates route maps based on static obstacles in the environment. It plans the shortest path towards agents’ respective destinations by generating one or more intermediate targets. In the second layer, the Social Force Model (SFM) is modified and extended for mixed traffic to produce feasible trajectories. Since car movements are not as flexible as pedestrian movements, velocity angle constraints are included for cars. The conflicts described in the third layer are resolved by rule-based constraints for shared space users. An optimisation algorithm is applied to determine the interaction parameters of the force-based model for shared space users using empirical data. This new three-layer microscopic model can be used to simulate shared space environments and assess, for example, new street designs.     

Airline competition and market frequency: A comparison of the s-curve and schedule delay models

We compare two common ways of incorporating service frequency into models of airline competition. One is based on the so called s-curve, in which, all else equal, market shares are determined by frequency shares. The other is based on schedule delay—the time difference between when travelers wish to travel and when flights are available. We develop competition models that differ only with regard to which of the above approaches is used to capture the effect of frequency. The demand side of both models is an approximation of a nested logit model which yields endogenous travel demand by including not traveling in the choice set. We find symmetric competitive equilibrium for both models analytically, and compare their predictions concerning market frequency with empirical evidence. In contrast to the s-curve model, the schedule delay model depicts a more plausible relationship between market share and frequency share and accurately predicts observed patterns of supply side behavior. Moreover, the predictions from both models are largely the same if we employ numerical versions of the model that capture real-world aspects of competition. We also find that, for either model, the relationship between airline frequency and market traffic is the same whether frequency is determined by competitive equilibrium, social optimality, or social optimality with a break-even constraint.     

Evaluating the social cost of cruise ships air emissions in major ports of Greece

Detailed NO_x, SO₂ and PM_2.5 emissions have been estimated for cruise ships in the five busiest Greek ports (i.e. Piraeus, Santorini, Mykonos, Corfu and Katakolo) for year 2013. The emissions were analyzed in terms of gas species, seasonality and activity. The total in-port inventory of cruise shipping accounted to 2742.7 tons: with NO_x being dominant (1887.5 tons), followed by SO₂ and PM_2.5 (760.9 and 94.3 tons respectively). Emissions during hotelling corresponded to 88.5% of total and have significantly outweighed those produced during ships’ maneuvering activities (11.5% of total). Seasonality was found to play a major role, as summer emissions and associated impacts were significantly augmented. The anticipated health impacts of ship emissions can reach to €24.3 million or to €5.3 per passenger proving the necessity of control of the emissions produced by cruise ships in port cities or policy and measures towards a more efficient cruise industry.     

The factors influencing bicycling in the Bangalore city

Bicycling, in an urban context, have many benefits, compared with motorized transports, like reduced carbon footprint, and lower maintenance, health, social and infrastructural costs. The present paper analyses the various factors contributing to a low percentage of bicycling in the Bangalore city and elicits certain policy aspects to improve the attractiveness of bicycling. The study focuses mainly on the behavioral aspects of commuters pertaining to their childhood and current scenario, and uses a face-to-face questionnaire survey for data collection. These behavioral aspects indicated a commuter’s perception about social expectation, convenience and bicycling infrastructure using a 5-point Likert scale measurement. Information is also collected about factors that might motivate bicycling, and about demographic variables like age, gender, income, etc. The study used a statistical z-test to identify the most influential attitudinal factors and to check whether the various factors are significantly different. The results gave a clear picture about the most dominant attitudinal factors that resulted in the stoppage of bicycling during a commuter’s childhood, and that acted as a deterrent to their bicycle usage in a current scenario. The study determined a need for changing the attitude of people towards cycling by programs that would create a positive image for cycling. There was also a need for segregated cycle lanes and signals at intersections so that people could feel safe while travelling on cycles.     

Exploring transportation equity: Development and application of a transportation justice framework

Recent efforts to emphasize social equity in transportation are emerging as local, regional and national governments have set initiatives to identify, existing and potential, disproportionate impacts to low-income and minority populations, also referred to as transportation justice (TJ). Currently, there are suggested methods for identifying transportation justice areas; however, there is no streamlined method instituted across transportation agencies. Each jurisdiction identifies transportation justice (or environmental justice) areas based on their own methodology, typically based on either average regional thresholds, graduated thresholds, or a more unique in-house index methodology. This research explores and evaluates existing methods and develops a rigorous and comprehensive method called the Transportation Justice Threshold Index Framework (TJTIF) using Geographic Information Systems (GIS), as well as factors based on demographics, socio-economics, and transportation/land use. The framework is applied to a case study region in Pennsylvania reflective of the Marcellus Shale impact area, highlighting Sullivan County, PA. The methodology and the case study application serve as an example for how transportation agencies throughout the country can promote social sustainability and enhance transportation equity.     

对新媒体环境下把握高校突发事件舆论主导权的因素与路径分析

当前,我国正处在经济社会剧烈转型的多元时代,矛盾问题集中凸显,突发事件易发高发,特别是在新媒体环境下,舆情应对任务日益艰巨繁重。高校作为大量人群集中和文化社会群体的特殊性,很容易引发突发事件,并成为社会媒介炒作的题材和人们关注的焦点,处置不当必然将严重影响学校和社会的安全稳定。     

教育应与区域社会经济协调发展

区域教育结构和教育体系已经不能适应区域社会经济的发展,也不能适应社会主义新农村的建设,必须按科学发展观的要求,重新定义区域教育的发展方向、结构和体系。区域教育的首要目标是促进和服务区域社会经济的协调发展。     

基于流媒体技术的网络视频监控系统设计

介绍流媒体技术基本原理、流媒体传输方式及传输过程。根据移动基站实际情况及用户需求,提出一种基于流媒体技术的网络视频监控系统设计方案,阐述视频监控系统的结构以及各组成部分的功能,并从多个方面分析系统的性能。该方案结构合理,功能完善,具有较强的实用性。     

基于社会剩余最大化的铁路繁忙线路货运定价策略研究

分析得出货主对运输成本的错误感知及部分支付是导致铁路繁忙线路需求拥挤的原因之一,按照个人边际成本确定的个人最优货运需求会导致社会剩余的流失,并未达到社会最优。提出通过收取需求拥挤费用,把拥挤效应的外部不经济性内部化,把货运需求调控在按照社会边际成本确定的社会最优货运量,以合理调节铁路繁忙线路货运供需均衡,达到社会剩余最大化,实现帕累托最优。     

铁路道碴瞬态电磁散射特性分析

引用离散随机媒质结构来模拟铁路道碴的分布情况，采用在ＦＤＴＤ法的差分网格中进行随机填充来实现铁路道碴的计算模拟模型，并求解其瞬态电磁散射场。通过对该散射场的处理，提取出道碴的非相关散射场，然后再对该非相关场进行分析，得出了可描述道碴分布状况的电磁参量。数值分析结果显示，该参量与道碴空隙率之间在一定范围内具有指数关系。这表明，用电磁方法来探测铁路道碴的空隙率是可能的。