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Showing papers on "Bus network published in 2019"


Journal ArticleDOI
TL;DR: It is demonstrated that energy storage systems are a potential remedy for high demand charges from fast-charging, by explicitly considering the electricity demand charges in the optimal deployment problem of fast- charging stations for battery electric bus systems.

115 citations


Journal ArticleDOI
TL;DR: This work shows with billions of vehicle observations, how road and bus network topology explains around 90% of the empirically observed critical point variation, making it therefore predictable, and finds a sublinear relationship between network size and critical accumulation emphasizing decreasing marginal returns of infrastructure investment.
Abstract: Traffic in an urban network becomes congested once there is a critical number of vehicles in the network. To improve traffic operations, develop new congestion mitigation strategies, and reduce negative traffic externalities, understanding the basic laws governing the network's critical number of vehicles and the network's traffic capacity is necessary. However, until now, a holistic understanding of this critical point and an empirical quantification of its driving factors has been missing. Here we show with billions of vehicle observations from more than 40 cities, how road and bus network topology explains around 90% of the empirically observed critical point variation, making it therefore predictable. Importantly, we find a sublinear relationship between network size and critical accumulation emphasizing decreasing marginal returns of infrastructure investment. As transportation networks are the lifeline of our cities, our findings have profound implications on how to build and operate our cities more efficiently.

114 citations


Journal ArticleDOI
TL;DR: A rule-based method for systematically generating and integrating alternative lining options into the frequency and resource allocation problem by considering the dual objective of reducing passenger waiting times at stops and reducing operational costs is proposed.
Abstract: Urban public transport operations in peak periods are characterized by highly uneven demand distributions and scarcity of resources. In this work, we propose a rule-based method for systematically generating and integrating alternative lining options, such as short-turning and interlining lines, into the frequency and resource allocation problem by considering the dual objective of (a) reducing passenger waiting times at stops and (b) reducing operational costs. The bus allocation problem for existing and short-turning/interlining lines is modeled as a combinatorial, constrained and multi-objective optimization problem that has an exponential computational complexity and a large set of decision variables due to the additional set of short-turning/interlining options. This constrained optimization problem is approximated with an unconstrained one with the use of exterior point penalties and is solved with a Genetic Algorithm (GA) meta-heuristic. The modeling approach is applied to the bus network of The Hague with the use of General Transit Feed Specification (GTFS) data and Automated Fare Collection (AFC) data from 24 weekdays. Sensitivity analysis results demonstrate a significant reduction potential in passenger waiting time and operational costs with the addition of only a few short-turning and interlining options.

56 citations


Journal ArticleDOI
TL;DR: In this article, the authors focus on the potential impact of various options for decarbonization of public bus transport in Stockholm, with particular attention to electrification, using a life cycle perspective and various implementation scenarios.

48 citations


Journal ArticleDOI
TL;DR: This study allows to evidence potential vulnerabilities of the urban networks, that must be considered to support the planning process into the creation of resilient structures, and implements a topological approach, using a multi-graph to model public transportation networks and analyse vulnerabilities.
Abstract: This paper presents some results devoted to providing network analysis functionalities for vulnerability assessment in public transportation networks with respect to disruptive events and/or targeted attacks to stations. The results have been obtained on two public transportation networks: the bus network in Florence, Italy, and the transportation network in the Attika region, Greece. The analysis implements a topological approach, based on graph theory, using a multi-graph to model public transportation networks and analyse vulnerabilities with respect to the removal of one or more of their components. Both directed attacks and cascading failures are considered. While the first type of disruptive events is related to a static analysis, where nodes are removed according to a rank related to some centrality measures, the second type is related to a dynamic analysis, where a failure cascade is simulated making unavailable the node with the highest betweenness value. Vulnerability measures are computed as loss of connectivity and efficiency, with respect to both the two different types of disruptive events considered. This study allows to evidence potential vulnerabilities of the urban networks, that must be considered to support the planning process into the creation of resilient structures.

32 citations


Journal ArticleDOI
TL;DR: The grid-interactive operation of electric buses is first time integrated within a dynamic market frame using the Distribution Locational Marginal Price algorithm for load congestion management.

29 citations


Journal ArticleDOI
TL;DR: A multi-objective framework for an optimal mix of different types of distributed energy resources (DERs) under different load models to maximize environmental, technical, and economic benefits by minimizing various objective functions subject to different power system constraints and uncertainty of renewable energy sources is offered.
Abstract: This article offers a multi-objective framework for an optimal mix of different types of distributed energy resources (DERs) under different load models. Many renewable and non-renewable energy resources like photovoltaic system (PV), micro-turbine (MT), fuel cell (FC), and wind turbine system (WT) are incorporated in a grid-connected hybrid power system to supply energy demand. The main aim of this article is to maximize environmental, technical, and economic benefits by minimizing various objective functions such as the annual cost, power loss and greenhouse gas emission subject to different power system constraints and uncertainty of renewable energy sources. For each load model, optimum DER size and its corresponding location are calculated. To test the feasibility and validation of the multi-objective water cycle algorithm (MOWCA) is conducted on the IEEE-33 bus and IEEE-69 bus network. The concept of Pareto-optimality is applied to generate trilateral surface of non-dominant Pareto-optimal set followed by a fuzzy decision-making mechanism to obtain the final compromise solution. Multi-objective non-dominated sorting genetic (NSGA-III) algorithm is also implemented and the simulation results between two algorithms are compared with each other. The achieved simulation results evidence the better performance of MOWCA comparing with the NSGA-III algorithm and at different load models, the determined DER locations and size are always righteous for enhancement of the distribution power system performance parameters.

25 citations


Journal ArticleDOI
21 Jun 2019
TL;DR: This paper investigates implicit components, including waiting and riding time, in multiple transportation systems in multiple Transportation systems under the impact of urban anomalies, and designs a learning-based model for travel time component prediction with anomalies.
Abstract: Urban anomalies have a large impact on passengers' travel behavior and city infrastructures, which can cause uncertainty on travel time estimation. Understanding the impact of urban anomalies on travel time is of great value for various applications such as urban planning, human mobility studies and navigation systems. Most existing studies on travel time have been focused on the total riding time between two locations on an individual transportation modality. However, passengers often take different modes of transportation, e.g., taxis, subways, buses or private vehicles, and a significant portion of the travel time is spent in the uncertain waiting. In this paper, we study the fine-grained travel time patterns in multiple transportation systems under the impact of urban anomalies. Specifically, (i) we investigate implicit components, including waiting and riding time, in multiple transportation systems; (ii) we measure the impact of real-world anomalies on travel time components; (iii) we design a learning-based model for travel time component prediction with anomalies. Different from existing studies, we implement and evaluate our measurement framework on multiple data sources including four city-scale transportation systems, which are (i) a 14-thousand taxicab network, (ii) a 13-thousand bus network, (iii) a 10-thousand private vehicle network, and (iv) an automatic fare collection system for a public transit network (i.e., subway and bus) with 5 million smart cards.

22 citations


Journal ArticleDOI
TL;DR: In this paper, a structural equation approach, with both numeric and ordinal Probit models, was employed to assess whether critical variables from the bus network reform affect users' satisfaction significantly.
Abstract: Before enduring a substantial network reform in a system, it is of utmost importance to understand if, how, and why the users’ perception of the system will be affected. In the PT literature, we find evidence about what drives users’ satisfaction. Still, past studies have utilised data that has been mostly retrieved from user surveys during periods where the network and its services were quite stable, or during an economic downturn, in contrast to facing a structural network transformation. Barcelona public bus company (TMB) reformed into a transfer based-network, the NXB (Nova Xarxa de Bus) since 2012. This reform allows discerning which operative, travel, and sociodemographic characteristics affect the users’ satisfaction and their priorities, during a major network reform. We use a three-year customer satisfaction survey (n = 12,511), for our study. Employing a structural equation (SEM) approach, with both numeric and ordinal Probit models, we assess whether critical variables from the bus network reform affect users’ satisfaction significantly. Following a two step-approach, initially an SEM-MIMIC model for the whole population, then a Multi-Group Analysis (MGA), we appraise for different satisfaction models across subpopulations. We propose a reflective latent variable to measure the socioeconomic status (SES), which resulted in significant and negative estimates towards satisfaction, as expected, in all models. Our most important result confirms that users value reliability over other latent satisfaction constructs. Besides the satisfaction constructs, users give an additional relevance to the NXB lines, indicating that intrinsically the users perceive added-value from these lines. Most of the transfers between buses and other transport modes do not affect bus-users satisfaction. Our results imply that efficiently designed transfer-based networks may be a suitable solution from users’ perspective.

21 citations


Journal ArticleDOI
TL;DR: A model based on betweenness and its solution method was developed to improve the public transportation network’s sustainability and discuss the possibility of optimizing the sustainability by network analyzing methods.
Abstract: Urban public transportation contributes greatly to sustainable urban development. An urban public transportation network is a complex system. It is meaningful for theory and practice to analyze the topological structure of an urban public transportation network and explore the spatial structure of an urban transportation network so as to mitigate and prevent traffic congestion and achieve sustainability. By examining the Xi’an bus network, the degree distribution, average path length, aggregation coefficient, and betweenness centrality of the bus station network were computed using models in complex network theory. The results show that the node degrees of the Xi’an bus network are unevenly distributed and present a polarization diagram with long average path length and high aggregation. A model based on betweenness and its solution method was developed to improve the public transportation network’s sustainability and discuss the possibility of optimizing the sustainability by network analyzing methods.

21 citations


Journal ArticleDOI
TL;DR: A new perspective to improve the reliability of a network is introduced, which aims at finding cost-effective portfolios of Prognostics and Health Management systems to be installed throughout the network.

Journal ArticleDOI
TL;DR: A cooperative control based algorithm using a vehicle to grid (V2G) technology based on a fuzzy logic approach is proposed to prevent cascading failures without loss incurrence to improve the accuracy of taking necessary actions to compensate these CFEs.
Abstract: The previously proposed algorithms for preventing cascading failures, which lead to a blackout event, involve specific load shedding schemes, which introduce incurring losses in the power system network. In this paper, a cooperative control based algorithm using a vehicle to grid (V2G) technology based on a fuzzy logic approach is proposed to prevent cascading failures without loss incurrence. The algorithm is implemented on a standard IEEE-30 bus system, and it uses mathematical combinations heuristically to identify the critical nodes through the use of a self-propagation graph to dispatch the optimum power from V2G. For the enhancement of computational speed, a network operator considers only those vulnerable nodes, which are identified by a self-propagating graph. Through this, a network operator can easily detect critical nodes by rooting straight to the vulnerable transmission lines in the IEEE-30 bus network. The probabilistic modeling in this paper is performed in such a way that network operators will mitigate cascading failures events (CFEs) after the occurrence of (N -1) and (N -1-1) contingencies/blackout events without performing load shedding. The detailed experimental analysis provides better visualization of the impact of CFEs on power grids to the power network operators and therefore significantly improves the accuracy of taking necessary actions to compensate these CFEs.

Journal ArticleDOI
TL;DR: A methodology for assessment of large-scale public transport network overhauls, building upon the previous development in service-equity assessment methods, based on the use of open timetable data and reveals the disaggregate effects of the network overhaul from a three-level spatial perspective.

Journal ArticleDOI
TL;DR: In this article, a detailed flow chart of a customized bus (CB) network planning methodology, including individual reservation travel demand data processing, CB line origin-destination (OD) area division considering quantity constraints of demand in areas and distance constraints based on agglomerative hierarchical clustering (AHC), an initial set of CB lines generating quantity constraints on each line and line length constraints, and line selection model building, striking a balance between operator interests, social benefits, and passengers' interests.
Abstract: With the advantages of congestion alleviation, environmental friendliness, as well as a better travel experience, the customized bus (CB) system to reduce individual motorized travel is highly popular in increasing numbers of cities in China. The line planning problem is a key aspect of the CB system. This paper presents a detailed flow chart of a CB network planning methodology, including individual reservation travel demand data processing, CB line origin–destination (OD) area division considering quantity constraints of demand in areas and distance constraints based on agglomerative hierarchical clustering (AHC), an initial set of CB lines generating quantity constraints of the demand on each line and line length constraints, and line selection model building, striking a balance between operator interests, social benefits, and passengers’ interests. Finally, the impacts of the CB vehicle type, the fixed operation cost of online car-hailing (OCH), and the weights of each itemized cost are discussed. Serval operating schemes for the Beijing CB network were created. The results show that the combination of CB vehicles with 49 seats and 18 seats is the most cost-effective and that CBs with low capacity are more cost-effective than those with larger capacity. People receive the best service when decision-makers pay more attention to environmental pollution and congestion issues. The CB network’s service acceptance rate and the spatial coverage increase with the fixed operating cost per OCH vehicle per day c 0 C . The CB vehicle use decreases as c 0 C c c increases. The results of this study can provide technical support for CB operators who design CB networks.

Journal ArticleDOI
TL;DR: A new DOCR coordination method based on the dynamic model of DOCR is presented to consider the effect of network topology change during the short circuit, formulated as a linear programming (LP) problem.

Proceedings ArticleDOI
01 Mar 2019
TL;DR: The research on the typical fault of the Profibus is carried out in a targeted manner, and the method of troubleshooting the fault point and fault type under the field Profibus fault condition of the converter station is summarized.
Abstract: Fieldbus (Profibus) systems are widely used in HVDC transmission projects. By monitoring the bus station activity status and bus electrical signal quality, it is possible to grasp the health status of the bus network, perform early identification and troubleshooting existing faults and potential problems, and deal with them in time to prevent the accumulation and further development of bus fault anomalies. The research on the typical fault of the Profibus is carried out in a targeted manner, and the method of troubleshooting the fault point and fault type under the field Profibus fault condition of the converter station is summarized. Through the longitudinal fault diagnosis research of the converter station, the field bus system of the high-end group control system 1 of the Sennan converter station is taken as the simulation object, and the faults of different types of fieldbus faults are diagnosed. the data interaction of the converter station control system is mastered, so that the status of each station device on the bus can be assisted at the data level, and the converter station control system can be directly grasped.

Journal ArticleDOI
TL;DR: An extended vehicle scheduling model is developed taking into account the interests of passengers and operators in attaining optimization of timetable synchronization integrated with vehicle scheduling and considering the passenger waiting cost, showing that both the fleet size of bus operators and the waiting cost of passengers are minimized.
Abstract: In the operational planning process of public transport, the time a passenger spends on waiting is a very critical element for judging passenger service. Schedule synchronization is a useful strategy for reducing bus waiting time and improving service connectivity. This paper develops an extended vehicle scheduling model, taking into account the interests of passengers and operators in attaining optimization of timetable synchronization integrated with vehicle scheduling and considering the passenger waiting cost. Deficit functions at terminals are formulated. Deadheading (DH), shifting departure time (SDT), and network flow technique are used for vehicle scheduling with the consideration of passenger waiting times. An experimental study in Beijing is conducted and three important bus lines are selected as a regional bus network to demonstrate the methodology developed. Results show that both the fleet size of bus operators and the waiting cost of passengers are minimized. For example, the minimum fleet size can be reduced from 28 vehicles to 24 ones while the passenger times are less than 20 minutes in this multidepot network.

Journal ArticleDOI
TL;DR: In this article, the authors integrate a dynamic transit assignment model into the tactical planning phase to determine frequency and vehicle capacity at the network level while accounting for the impact of service variations on users and operator costs.
Abstract: We integrate for the first time, to our knowledge, a dynamic transit assignment model into the tactical planning phase. The settings of service frequencies and vehicle capacities determine line capacity and have significant consequences for level-of-service and operational costs. The objective of this study is to determine frequency and vehicle capacity at the network level while accounting for the impact of service variations on users and operator costs. To this end, we propose a simulation-based optimization approach. The proposed model allows accounting for variations in service headways and crowding as well as their consequences for passenger flows distribution, all of which have not been accounted for in the tactical planning so far. Practical benefits of the model are demonstrated by an application to a bus network in the Amsterdam metropolitan area. This study contributes to the development of a new generation of methods that integrate reliability into the tactical planning phase to improve service quality.

Journal ArticleDOI
TL;DR: This paper introduces the TNDP as a many-objective optimization problem that generates a diverse set of alternative solutions and finds $\theta $ -DEA to be the most robust among the employed algorithms.
Abstract: In many cities around the world, private vehicles are increasingly causing severe traffic congestion, pollution, and accidents. Public transports have been widely recognized as an effective way to improve urban life. To dissuade citizens from using private vehicles, it is necessary to design a practical, efficient, and economical public bus network. The transit network design problem (TNDP) determines the transit network (i.e., public bus network) for a city. It involves different stakeholders with diverse interests and values. To capture their conflicting expectations, numerous optimization objectives arise naturally. This paper introduces the TNDP as a many-objective optimization problem that generates a diverse set of alternative solutions. We apply several state-of-the-art many-objective evolutionary algorithms for the newly formulated TNDP. To efficiently explore the high-dimensional objective space of the TNDP, we develop problem-specific genetic operators for the evolutionary algorithm. We rigorously tested our approach on several benchmark datasets. The simulation results exhibit the effectiveness of the approach in addressing the challenges of a modern city. Based on the obtained results, we found $\theta $ -DEA to be the most robust among our employed algorithms. In addition, we observed the usefulness of the crossover operator, which randomly combines two solutions into one, and a simple mutation scheme, which is not biased to any objective function, to handle the many-objective nature of the TNDP.

Journal ArticleDOI
TL;DR: In this paper, an incentive subsidy scheme based on the Laffont-Tirole model is designed to motivate bus operators to endeavor to reduce deficits so as to obtain a premium, thus minimizing the total amount of subsidies and maximizing social benefit.
Abstract: Large public transport subsidies necessitated by operating deficits have become a heavy financial burden on some local governments. However, the present subsidy scheme lacks incentives to encourage bus operators to reduce deficits to lessen subsidies. In order to motivate bus operators to exert their roles in reducing these subsidies to ensure sustainable finance, this paper designs an incentive subsidy scheme based on the Laffont–Tirole model. This scheme is designed to motivate bus operators to endeavor to reduce deficits so as to obtain a premium, thus minimizing the total amount of subsidies and maximizing social benefit. The case of the bus network in Kumamoto, Japan, shows how, with this subsidy scheme, bus operators can play roles in lessening subsidies, allowing a win-win situation for both bus operators and the local government, and maximizing social benefit to realize the sustainability of the city. Finally, findings of our sensitivity analysis with imperfect information suggest that the length of bus lines in a network should be shortened in order to avoid cost waste to lessen subsidies.

Journal ArticleDOI
TL;DR: The authors find that the bus network in Hanoi, Vietnam is robust against random failure but sensitive to targeted attack, in agreement with its scale-free character.
Abstract: Many complex networks exist to facilitate the transport of material or information. In this capacity, the authors are often concerned with the continued flow of material or information when a fraction of the links in the complex network is disrupted. In other words, the authors are interested in the robustness of the complex network. In this paper, the authors survey measures of robustness like the average path length, the average clustering coefficient, the global efficiency, the size of largest cluster and use these to analyze the robustness of the bus network in Hanoi, Vietnam. The authors find that the bus network is robust against random failure but sensitive to targeted attack, in agreement with its scale-free character. By examining sharp drops in the average path length within the largest cluster of the Hanoi bus network under successive targeted attack, the authors identify five nodes whose loss lead to the fragmentation of the network into five or six disconnected clusters. These isolated clusters represent geographically the Central, Western, Southern, and Northwestern districts of Hanoi. Special considerations must therefore be given to these five nodes when planners wish to expand the bus network, or make it more robust.

Journal ArticleDOI
TL;DR: This study investigated the spatial characteristics of an urban bus service system by using the complex network approach and found that the P-space method can provide insights into the statistical laws and distinct convenient areas in a bus service network, and consequently aid in optimizing the allocation of bus stops and routes.
Abstract: The urban bus service system is one of the most important components of a public transport system. Thus, exploring the spatial configuration of the urban bus service system promotes an understanding of the quality of bus services. Such an understanding is of great importance to urban transport planning and policy making. In this study, we investigated the spatial characteristics of an urban bus service system by using the complex network approach. First, a three-step workflow was developed to collect a bus operating dataset from a public website. Then, we utilized the P-space method to represent the bus service network by connecting all bus stop pairs along each bus line. With the constructed bus network, a set of network analysis indicators were calculated to quantify the role of nodes in the network. A case study of Shenzhen, China was implemented to understand the statistical properties and spatial characteristics of the urban bus network configuration. The empirical findings can provide insights into the statistical laws and distinct convenient areas in a bus service network, and consequently aid in optimizing the allocation of bus stops and routes.

Journal ArticleDOI
TL;DR: In this article, the authors used Extended Convergent Cross Mapping (ECCM) to assess the causal relationship between two variables without modelling and found that increasing BK attracted more public transit passengers during the period 2007 to 2010.
Abstract: To create a sustainable urban transportation environment, transportation authorities often implement incentive strategies to attract new public transportation users. Various studies have shown that increasing bus revenue vehicle-kilometers (BK) is a key factor for increasing bus ridership (BR). In this situation, BK affects BR. However, an increase in BR may lead to an increase in BK. Then, BR affects BK. The existence and directions of causal effects between BK and BR are the research questions addressed in this study. Since 2007, the Taichung City Government has been adding and adjusting bus routes to build a dense bus network. In 2011, it implemented a free fare bus policy. BR grew from ca. 2 million per month in 2007 to 10 million per month in 2015. Moreover, BK increased by ca. 3 times during that same period. This provides an opportunity to understand the causal effects between BK and BR. Extended convergent cross mapping (ECCM) can be used to assess the causal relationship between two variables without modelling. We adopted this method to distinguish the influences of BK and BR. According to the results, increasing BK attracted more public transit passengers during the period 2007 to 2010. However, there was no effect of BR on BK. After implementation of free fare bus policy in 2011, increases in BK led to increases in BR and increases in BR drove incremental growth of BK. The result was a virtuous cycle of mutual influence between BK and BR. In conclusion, increasing BK, such as route length or number of scheduled runs, can promote the usage of public transportation. Moreover, authorities can implement free fare bus policy to attract potential users and force incremental growth of BK.

Journal ArticleDOI
TL;DR: Based on this successful experience of reforming the urban bus system, the authors analyzed the structural change in bus ridership time series over a period of more than a decade, which can be used to continue to formulate or adjust public transportation policies.
Abstract: Since 2001, the Taichung City Government has launched several policies to stimulate public transit ridership. Based on this successful experience of reforming the urban bus system, the aims of this study are to analyze the structural change in bus ridership time series over a period of more than a decade. The major objectives are to determine effective policies and explore critical factors. According to monthly ridership from 2001 to 2014, five regimes of bus ridership and three effective bus policies were defined. Important elements of successful policies include complete bus network, high frequency of buses and mileage subsidy. These policies have brought high growth to once very low bus ridership in Taichung City. This type of research process helped to provide an understanding of actual outcomes of past policies, as well as to obtain key factors, which can be used to continue to formulate or adjust public transportation policies. The results of this study may serve not only as a reference for formulating bus strategy in Taichung City, but also for providing direction in the development of public bus service in similar-sized cities.

Journal ArticleDOI
TL;DR: The big global positioning systems (GPS) trajectory data is used to analyzed the headway stability of bus system from the perspective of network and a statistical method is proposed to analyze the operational vehicle performance of bus network.
Abstract: The operational stability of public transport is significant for both passengers and operators. Affected by many stochastic factors, such as traffic congestion, traffic signals and passenger demand at stops, the headway always become uneven, which greatly reduces the service quality. This paper used the big global positioning systems (GPS) trajectory data to analyze the headway stability of bus system from the perspective of network. A statistical method is proposed to analyze the operational vehicle performance of bus network. The GPS trajectory data of Jinan is used to test the model. The results show that the average dwell time, actual headway, and headway stability index of stations follow lognormal distributions with obvious right tails. Moreover, the seriously unstable situations do not appear in the peak hours, but in the time periods before peak hours. In addition, the stations with most unstable headway are located in the suburbs and the fringe area of downtown. The outcomes suggest that operators should pay more attention to the suburbs and the fringe area of downtown, and the time periods before peak hours to efficiently improve the service quality.

Journal ArticleDOI
TL;DR: Metropolitan Sydney has a transport system that is substantial and robust, and appears to offer relatively similar spatial accessibility for all socioeconomic groups, an example of great urban planning.
Abstract: Objective The aim of this study was to examine the spatial accessibility of the aged and older adult population of the greater Sydney region to the bus public transport network, and the proximity of this transportation route to public and private dental services. Methods This study used geographic information systems (GIS) to examine, at a population level, the spatial accessibility of the public transport network and dental provider locations. The prime focus of the present study was on the aging population residing within 50 km of the General Post Office of metropolitan Sydney. Retirees (aged ≥65 years) and older adults (aged ≥85 years) were the two subsets of the aging population. Results Sydney's bus network is currently supplying bus transport to both older and disadvantaged groups, facilitating the needs of more than half a million older people. Regardless of socioeconomic status, 12% of the entire population, 11.5% of retirees and 10.8% of older adults resided 500 m away from accessible medium-frequency bus stops. Approximately 40% of the overall population consisted of people of lower socioeconomic status living within 500 m of a medium-frequency bus stop, whereas 60% of the population were of a high socioeconomic status and lived within 500 m of a medium-frequency bus stop. Conclusion Metropolitan Sydney has a transport system that is substantial and robust, and appears to offer relatively similar spatial accessibility for all socioeconomic groups. This system is an example of great urban planning, where the distribution of bus stops is evenly positioned in both high-density areas and areas of low socioeconomic status. What is known about the topic? Older adults and disadvantaged people suffer from higher levels of dental disease compared with the rest of the population. Older adults and disadvantaged people are more likely to rely on public transport to access healthcare services, including dental care. The Australian population is aging rapidly. What does this paper add? Although a previous study examined the accessibility to services via the train network, this is the first analysis of the spatial accessibility to dental services via the bus network in Sydney. Most older adults and disadvantaged people in Sydney enjoy acceptable spatial access to the public transport network, and thereby to dental practices. Urban planning, in terms of determining healthcare service locations and the public transport network, needs to consider the distribution of older adults and disadvantaged populations. What are the implications for practitioners? Practitioners are more likely to attract older adult patients to their practices or clinics if these are located within easy access to the public transport network.

Journal ArticleDOI
TL;DR: This paper shows a reduced wiring technology for CAN to enhance the network scalability and the cost efficiency and shows how to reduce networking material in a car and develop a sustainable society by establishing more scalable CAN networks.
Abstract: Controller area network (CAN) has been widely adopted as an in-vehicle communications standard. CAN with flexible data-rate (CAN FD) is defined in the ISO standards to achieve higher data rates than the legacy CAN. A number of CAN nodes can be connected by a single transmission medium, i.e. CAN enables us to constitute cost-effective bustopology networks. CAN puts carrier sense multiple access with collision resolution (CSMA/CR) into practice by using bit-wise arbitration based on wired logical AND in the physical layer. The most prioritized message is delivered without interruption if two or more CAN nodes transmit messages at the same time due to the bit-wise arbitration. However, the scalability of CAN networks suffers from ringing caused by the signaling mechanism establishing the wired logical AND.We need to reduce networking material in a car in order to reduce the car weight, save the fuel and the cost, and develop a sustainable society by establishing more scalable CAN networks. In this paper, we show a reduced wiring technology for CAN to enhance the network scalability and the cost efficiency. key words: CAN, CAN FD, bus topology, CSMA/CR, wired logical AND, bit-wise arbitration, ringing, reduced wiring

Journal ArticleDOI
16 Feb 2019
TL;DR: Techniques used in order to obtain parameters for a standard IEEE – 30 bus and IEEE-57 bus network are presented and a comparison into the differences with regard to computational time and effectiveness of each solver is made.
Abstract: Load flow studies are carried out in order to find a steady state solution of a power system network. It is done to continuously monitor the system and decide upon future expansion of the system. The parameters of the system monitored are voltage magnitude, voltage angle, active and reactive power. This paper presents techniques used in order to obtain such parameters for a standard IEEE – 30 bus and IEEE-57 bus network and makes a comparison into the differences with regard to computational time and effectiveness of each solver

Proceedings ArticleDOI
01 Dec 2019
TL;DR: The genetic algorithm method is applied to obtain optimal locations of these wind turbines in the grid to maximize the load margin while taking into account all constraints.
Abstract: In this article, we have proposed to maximize the voltage stability of an electrical grid by integrating several wind turbines. For this purpose, we have applied the genetic algorithm method to obtain optimal locations of these wind turbines in the grid. This optimization aims to maximize the load margin while taking into account all constraints. The proposed optimization method was applied on the modified IEEE 30 bus network.

Patent
01 Mar 2019
TL;DR: In this article, a customized bus line opening optimization method based on real-time requirements is proposed, which comprises the following steps of: establishing a bus network system, comprising the selection of a network node, the determination of a route path and the choice of a parking node; customizing the bus lines opening conditions, including: realtime demand user information acquisition and demand response time determination; a method for customize a bus networks model and passenger classification comprising that steps of establishing a spatio-temporal road network, determining a spatiotemporal window of passengers and classify passengers;
Abstract: The invention relates to a customized bus line opening optimization method based on real-time requirements, which comprises the following steps of: establishing a customized bus network system, comprising the selection of a network node, the determination of a network path and the selection of a parking node; customizing the bus line opening conditions, including: real-time demand user informationacquisition and demand response time determination; a method for customize a bus network model and passenger classification comprise that steps of: establishing a spatio-temporal road network, determining a spatio-temporal window of passengers and classify passengers; Initial customization of bus route generation model, including establishing a Route Optimization Model with Minimum Total passenger-Operator Cost; Initial customized bus route generation algorithm is to use column generation algorithm to determine the initial customized bus route; Optimize customized bus routes that have been opened. The invention can greatly improve the flexibility of the customized bus, so that the customized bus has more advantages in the travel mode selection, thereby improving the present situation of low seating rate of the customized bus, and finally improving the share rate of the customized bus travel mode.