Resilience assessment model for urban public transportation systems based on structure and function

Urbanization and the increasing frequency of extreme climates affect the sustainability of urban public transportation systems,and improving resilience is one of the primary directions for sustainable development.To scientifically assess the resilience of urban public transportation systems,a resilience assessment model based on structure and function is established in this study.This model mathematically quantifies and simulates the structural and functional changes in public transportation systems under disruption scenarios and provides a comprehensive assessment of six abilities:1)structural resistance,2)structural recoverability,3)functional resistance,4)functional recoverability,5)passenger adaptability,and 6)management adaptability.Depending on the initial failure stations,this model can simulate the resilience of a public transportation system under various scenarios.This model is applied to assess the resilience of public transportation systems in a provincial capital city under an equipment failure scenario.The results show that the impact of equipment failure on resilience varies according to the metro lines,and improvement strategies for functional recoverability and management adaptability are proposed.The weaknesses in the resilience of urban public transportation systems can be identified using the proposed model,which helps provide strategies for improving the capacity to face perturbations.

QoE-based video segments caching strategy in urban public transportation system

With the rapid development of vehicle-based applications, entertainment videos have gained popularity for passengers on public vehicles. Therefore, how to provide high quality video service for passengers in typical public transportation scenarios is an essential problem. This paper proposes a quality of experience(QoE)-based video segments caching(QoE-VSC) strategy to guarantee the smooth watching experience of passengers. Consequently, this paper considers a jointly caching scenario where the bus provides the beginning segments of a video, and the road side unit(RSU) offers the remaining for passengers. To evaluate the effectiveness, QoE hit ratio is defined to represent the probability that the bus and RSUs jointly provide passengers with desirable video segments successfully. Furthermore, since passenger volume change will lead to different video preferences, a deep reinforcement learning(DRL) network is trained to generate the segment replacing policy on the video segments cached by the bus server. And the training target of DRL is to maximize the QoE hit ratio, thus enabling more passengers to get the required video. The simulation results prove that the proposed method has a better performance than baseline methods in terms of QoE hit ratio and cache costs.

Fuzzy Analysis and Evaluation of Public Transport Service Quality: A Case Study of Dar es Salaam City, Tanzania

Urban public transport plays a critical role in stimulating economic development of any nation since most of the revenues come from cities. The majority of the city dwellers of any country use public transport. The evaluation of public transport service quality provides a valuable feedback to commuter operators to ensure continuous improvement of level of service and to the government to take appropriate measures for enhancing the quality of public transport service. This paper analyses and evaluates service quality of Road Public Transport (RPT) (i.e. minibuses and buses) and Urban Rail Transport (URT) in Dar es Salaam City, Tanzania. Since service quality and its attributes are intangible and vague, a fuzzy evaluation model is developed and applied. The formulated model is composed of Fuzzy Entropy Method (FEM) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). The overall evaluation procedure is as follows: initially, an intensive literature search and experts’ opinions are employed to establish criteria for evaluating the service quality of public transport in Dar es Salaam City. The developed FEM is used to obtain criteria weight. Lastly, the formulated TOPSIS is used to provide an overall ranking of urban public transport service quality. The overall evaluation shows that urban rail transport outperforms road public transport in terms of service quality. Nevertheless, the urban rail transport service in Dar es Salaam City is currently not well developed as it is provided on very limited routes. Thus, the Tanzania government, the rail transport operator i.e. Tanzania Railway Limited (TRL) and the agency responsible for the provision of rail infrastructure i.e. Reli Assets Holding Company (RAHCO) are advised to design and employ Public-Private-Partnership (PPP) schemes i.e. concession contracts to invest more in rolling stocks, locomotives and rail wagons so that the rail transport service is available on many routes of the road public transport to bring fair competition between the two operators.

Research on Public Traffic Vehicles Dispatch Based on Improved Adaptive Genetic Algorithm

Bus dispatching has been studied,and also the bus dispatching model is set up.Then,Genetic Algorithm is adaptively improved in order to avoid premature problem and the slow convergence,and then the keeping optimal strategy is used to the Genetic Algorithm,so formed the Improved Adaptive Genetic Algorithm,namely IAGA. Finally,the IAGA is used to optimizing the bus dispatching model,and the results of the simulation indicate IAGA has the higher efficiency than simple GA and is one effective way to optimizing the bus dispatching.

Hanoi Public TransportmTransformation by Management Using Action Research and Behavior Setting Theory

After the economic reforms in Vietnam, the number of motorbikes surged while public transport lost its passengers. No funds for investment available TRAMOC （Transport Management and Operation Centre）, the Transport Management and Operation Center started the experiment of transforming Hanoi Public Transport by management based on action research, introducing some interventions, which had shown to be effective in Europe. Phase I of the experimental approach was carried out with the smallest company that operated Line 32. The number of daily passengers surged from 1,700 to 8,000. In Phase II, the experiment was extended to the whole net. In 2001, there were 35,000 passengers per day, in 2010, there were 1 million; this is an increase of 3,000%. The result surpassed by far the expectations. The key for understanding the surprising results is the mode choice. 53% of the users are riders by choice; they have access to a car or motorbike. Simulation of the decisions as rational choice based on time needed for trips was proved to be quite accurate. Behavior was analyzed in the frame of behavior setting theory, which brings together urban structure and the design of the transport system. Success with introducing public transport needs a self-reliant leadership, which works with people in their real life situation. An urban transport system is part of the organized behavior of the people, who make use of the technical opportunities offered.

SUSTAINABILITY ON THE URBAN SCALE:‘GREEN URBANISM’—MARK Ⅱ

In the essay entitled‘Towards a Sustainable City Centre’(published in JGB Summer 2006),the author reflected on principles how to best integrate ecologically sustainable development(ESD)into urban design.This second paper reports on his continuing research in the area of‘Green Urbanism’.1 Among the most significant environmental challenges of our time are global climate change,excessive fossil fuel de-pendency and the growing demand for energy—all likely to be major challenges of the 21st century and one of the great-est problems facing humanity.In this context,urban design and the fundamental principles of how to shape our cities has barely featured in the greenhouse debate.Much of the debate in related areas has so far circled around ideas about active technology for‘eco-buildings’.This is surprising,since almost half the energy consumed is used in cities and urban built-up areas,and given that avoiding mistakes in urban design at early stages could genuinely lead to more sustain-able cities and less greenhouse gas emission.This article reflects upon practical strategies focused on increasing sustain-ability beyond and within the scope of individual buildings.The paper deals with cross-cutting issues in architecture and urban design and addresses the question of how we can best cohesively integrate all aspects of energy systems,transport systems,waste and water management,passive and active strategies,climatisation and so on,into contemporary urban design and improved environmental performance of our cities.It provides a context for a general debate about the regeneration of the city centre,and discusses how urbanism is affected(and can be expected to be even more affected in future)by the paradigms of ecology.The significance of the research is found in the pressing need for an integration of sustainability principles in the urban design process of cities in South East Asia and the general need for a sustainable city development.It will be of particular relevance to the rapid urban growth of developing cities that have,in the past,frequently been poorly man-aged.Research in sustainable urban design recommends increased harnessing of the energies manifested in the existing fabrics—for instance,through the adaptive re-use of former industrial(brownfield)sites and the upgrade and extension of existing building structures.It is less environmentally damaging to stimulate growth within the established city cen-tre rather than sprawling into new,formerly un-built areas.Two recent examples for the application of such urban de-sign principles are the author’s proposals for the Australian city of Newcastle:the‘City Campus’and‘Port City’projects.