Showing papers on "Bus network published in 2017"
TL;DR: In this paper, the authors present the structure and application of a model developed for optimizing the distribution of charging infrastructure for electric buses in the urban context, and test the model for the bus network of Stockholm.
Abstract: Charging infrastructure requirements are being largely debated in the context of urban energy planning for transport electrification. As electric vehicles are gaining momentum, the issue of locating and securing the availability, efficiency and effectiveness of charging infrastructure becomes a complex question that needs to be addressed. This paper presents the structure and application of a model developed for optimizing the distribution of charging infrastructure for electric buses in the urban context, and tests the model for the bus network of Stockholm. The major public bus transport hubs connecting to the train and subway system show the highest concentration of locations chosen by the model for charging station installation. The costs estimated are within an expected range when comparing to the annual bus public transport costs in Stockholm. The model could be adapted for various urban contexts to promptly assist in the transition to fossil-free bus transport. The total costs for the operation of a partially electrified bus system in both optimization cases considered (cost and energy) differ only marginally from the costs for a 100% biodiesel system. This indicates that lower fuel costs for electric buses can balance the high investment costs incurred in building charging infrastructure, while achieving a reduction of up to 51% in emissions and up to 34% in energy use in the bus fleet.
196 citations
TL;DR: This paper addresses upcoming challenges for transport authorities during the electrification process of the bus fleets and sharpens the focus on infrastructural issues related to the fast charging concept by developing a mixed-integer linear optimization model for charging infrastructure and battery capacity.
184 citations
TL;DR: This work proposes a prediction engine that, given a scheduled bus journey (route) and a 'source/destination' pair, provides an estimate for the traveling time, while considering both historical data and real-time streams of information that are transmitted by buses.
93 citations
TL;DR: In this article, a sensitivity analysis approach is used for selecting the buses for the placement of distributed generations operating at unity power factor, which is done in two ways i.e., non-sequential placement and sequential placement of DG in a distribution network.
Abstract: This paper presents the reconfiguration of the distribution network in the presence of distributed generations (DGs) by considering two bus types i.e., P bus and PQV bus (remotely voltage controlled bus). The ‘P’ bus is represented by active power specification only whereas the PQV bus is one whose voltage is remotely controlled by the P bus. A methodology is proposed to select the P bus for controlling the voltage magnitude of remotely located PQV bus. A sensitivity analysis approach is used for selecting the buses for the placement of DGs operating at unity power factor. The placement of DGs is done in two ways i.e., non-sequential placement and sequential placement of DG in a distribution network. Genetic algorithm (GA) technique is used for the optimization of DGs followed by network reconfiguration. The objective function for network reconfiguration in this paper is considered to be real power loss reduction. Effectiveness of the proposed method is demonstrated through examples of 33 bus and 69 bus distribution networks.
58 citations
TL;DR: In this paper, the authors proposed a hub and shuttle model consisting of a combination of a few high-frequency bus routes between key hubs and a large number of shuttles that bring passengers from their origin to the closest hub and take them from their last bus stop to their destination.
Abstract: The BusPlus project aims at improving the off-peak hours public transit service in Canberra, Australia. To address the difficulty of covering a large geographic area, proposes a hub and shuttle model consisting of a combination of a few high-frequency bus routes between key hubs and a large number of shuttles that bring passengers from their origin to the closest hub and take them from their last bus stop to their destination. This paper focuses on the design of the bus network and proposes an efficient solving method to this multimodal network design problem based on the Benders decomposition method. Starting from a mixed-integer programming (MIP) formulation of the problem, the paper presents a Benders decomposition approach using dedicated solution techniques for solving independent subproblems, Pareto-optimal cuts, cut bundling, and core point update. Computational results on real-world data from Canberra’s public transit system justify the design choices and show that the approach outperforms the MIP...
57 citations
TL;DR: A methodological framework that includes the elements of large-scale travel demand data processing and analysis, hierarchical clustering-based route origin-destination (OD) region division, route OD region pairing, and a route selection model is proposed for CB network design is proposed.
Abstract: In recent years, an innovative public transportation (PT) mode known as the customized bus (CB) has been proposed and implemented in many cities in China to efficiently and effectively shift private car users to PT to alleviate traffic congestion and traffic-related environmental pollution. The route network design activity plays an important role in the CB operation planning process because it serves as the basis for other operation planning activities, for example, timetable development, vehicle scheduling, and crew scheduling. In this paper, according to the demand characteristics and operational purpose, a methodological framework that includes the elements of large-scale travel demand data processing and analysis, hierarchical clustering-based route origin-destination (OD) region division, route OD region pairing, and a route selection model is proposed for CB network design. Considering the operating cost and social benefits, a route selection model is proposed and a branch-and-bound-based solution method is developed. In addition, a computer-aided program is developed to analyze a real-world Beijing CB route network design problem. The results of the case study demonstrate that the current CB network of Beijing can be significantly improved, thus demonstrating the effectiveness of the proposed methodology.
55 citations
TL;DR: The alternative-fuel multiple depot vehicle scheduling problem is formally defined and formulated as an integer program, and a branch-and-price algorithm is proposed to solve the problem.
Abstract: Alternative-fuel vehicles are gaining popularity as a mode of transit, and research is being done into how current infrastructure can accommodate them. The problem of vehicle scheduling consists of assigning a fleet of vehicles to service a given set of trips with start and end times. Vehicle scheduling changes when alternative-fuel vehicles are used since the vehicles can carry only a limited amount of fuel and can refuel only at fixed locations. This paper presents the alternative-fuel multiple depot vehicle scheduling problem, a modification of the standard multiple depot vehicle scheduling problem where there is a given set of fueling stations and a fuel capacity for the vehicles. The problem is formally defined and formulated as an integer program, and a branch-and-price algorithm is proposed to solve the problem. A heuristic solution is also presented, and both are tested on randomly generated data and data on the Valley Metro bus network in the Phoenix, Arizona, metropolitan area.
52 citations
TL;DR: A multi-step methodology for mining smart card data is developed to analyse the spatial-temporal characteristics of bus travel demand and provides a practical set of visual analytics for transit trip characterisation.
48 citations
Patent•
20 Mar 2017
TL;DR: In this article, the authors implemented a cloud-based controller to control a Wi-Fi network with a plurality of access points, where the configuration comprises a topology of the network and the topology comprises the plurality of APs selectively interconnected to one another via backhaul links.
Abstract: Systems and methods implemented by a cloud-based controller to control a Wi-Fi network with a plurality of access points include obtaining measurements from the Wi-Fi network; determining a configuration of the Wi-Fi network based on the measurements, wherein the configuration comprises a topology of the Wi-Fi network and the topology comprises the plurality of access points selectively interconnected to one another via backhaul links; and providing the configuration to the Wi-Fi network for implementation thereof
38 citations
TL;DR: This work builds a community-based backbone by applying community detection techniques and proposes a two-level routing scheme which operates over the backbone, and develops a probabilistic model to analyze the message delivery latency of CBS.
Abstract: Compared to general vehicular systems, bus systems have advantages including wide coverage, fixed routes, and regular service. Inspired by these unique features of the bus systems, we propose to use the bus systems as routing backbones of VANETs. In this work, we present a Community-based Bus System (CBS) which consists of two components: a community-based backbone and a routing scheme over the backbone. The backbone construction is a one-off operation which is done offline while the routing is done online in individual buses. We build a community-based backbone by applying community detection techniques and propose a two-level routing scheme which operates over the backbone. The proposed routing scheme performs sequentially in the inter-community level and the intra-community level, and is able to support message delivery to both buses and specific locations/areas. We develop a probabilistic model to analyze the message delivery latency of CBS. The average error of the analytically-derived latency is shown to be 8.9 percent of the latency derived from the real traces. Extensive experiments are conducted on real-world traces from the Beijing bus system and the Dublin bus system and the results show that CBS can significantly lower the delivery latency and improve the delivery ratio, compared to the existing solutions. CBS is a general solution which is applicable to any bus-based VANETs.
35 citations
TL;DR: In this paper, a model of overall satisfaction based on level of satisfaction using a specific set of factors that take into account the individual characteristics of users and the differential effect of using different bus lines is presented.
TL;DR: In this article, the authors propose a synthesis procedure for designing the agents' state estimators and the event triggering thresholds, which is guaranteed to be stable and to satisfy a predefined estimation performance criterion.
Abstract: In this work, a dynamic system is controlled by multiple sensor-actuator agents, each of them commanding and observing parts of the system's input and output. The different agents sporadically exchange data with each other via a common bus network according to local event-triggering protocols. From these data, each agent estimates the complete dynamic state of the system and uses its estimate for feedback control. We propose a synthesis procedure for designing the agents' state estimators and the event triggering thresholds. The resulting distributed and event-based control system is guaranteed to be stable and to satisfy a predefined estimation performance criterion. The approach is applied to the control of a vehicle platoon, where the method's trade-off between performance and communication, and the scalability in the number of agents is demonstrated.
TL;DR: This work gives Trojan channel circuitry specifics for AMBA AXI4 and advanced peripheral bus (APB), and creates an SoC design running a multiuser Linux OS to demonstrate how a Trojan channel can allow an unprivileged user access to root-user data.
Abstract: On-chip bus implementations must be bug-free and secure to provide the functionality and performance required by modern system-on-a-chip (SoC) designs. Regardless of the specific topology and protocol, bus behavior is never fully specified, meaning there exist cycles/conditions where some bus signals are irrelevant, and ignored by the verification effort. We highlight the susceptibility of current bus implementations to Hardware Trojans hiding in this partially specified behavior, and present a model for creating a covert Trojan communication channel between SoC components for any bus topology and protocol. By only altering existing bus signals during the period where their behaviors are unspecified , the Trojan channel is very difficult to detect. We give Trojan channel circuitry specifics for AMBA AXI4 and advanced peripheral bus (APB), then create a simple system comprised of several master and slave units connected by an AXI4-Lite interconnect to quantify the overhead of the Trojan channel and illustrate the ability of our Trojans to evade a suite of protocol compliance checking assertions from ARM. We also create an SoC design running a multiuser Linux OS to demonstrate how a Trojan communication channel can allow an unprivileged user access to root-user data. We then outline several detection strategies for this class of Hardware Trojan.
TL;DR: The event-based design is shown to emulate the performance of a centralised state observer design up to guaranteed bounds, but with reduced communication.
Abstract: An event-based state estimation approach for reducing communication in a networked control system is proposed. Multiple distributed sensor agents observe a dynamic process and sporadically transmit their measurements to estimator agents over a shared bus network. Local event-triggering protocols ensure that data is transmitted only when necessary to meet a desired estimation accuracy. The event-based design is shown to emulate the performance of a centralised state observer design up to guaranteed bounds, but with reduced communication. The stability results for state estimation are extended to the distributed control system that results when the local estimates are used for feedback control. Results from numerical simulations and hardware experiments illustrate the effectiveness of the proposed approach in reducing network communication.
13 Dec 2017-Canadian Journal of Electrical and Computer Engineering-revue Canadienne De Genie Electrique Et Informatique
TL;DR: A novel zone detection method has been used where a large power network is divided into optimal number of zones with manageable number of buses and lines to reduce the computational burden in dealing with a large volume of waveform data.
Abstract: This paper presents a waveform analysis-based approach for detection and classification of short-circuit faults in large power networks. To reduce the computational burden in dealing with a large volume of waveform data, a novel zone detection method has been used where a large power network is divided into optimal number of zones with manageable number of buses and lines. A first module of the artificial neural network-based classifier has been developed to perform an “exploratory global search” to find the faulty zone, which is then refined to a “local search” within a zone, by a second module of classifier for determination of exact fault location and fault type. The elementary waveform data are being captured by disturbance recorders placed at strategic buses, termed as “monitoring locations.” Feature extraction, which is typically the underlying principle of any waveform analysis-based fault detection approach, is implemented by the extended Kalman filter. The proposed method has been successfully tested on the IEEE 57 bus network with encouraging results.
TL;DR: Ordinal optimization (OO) technique has been applied to estimate the transformer tap position for the first time in an unbalanced three-phase distribution network model and it is demonstrated that OO performs better than weighted least square as it provides higher accuracy of the loss calculation.
Abstract: This paper has discussed transformer tap position estimation with continuous and discrete variables in the context of three-phase distribution state estimation (SE). Ordinal optimization (OO) technique has been applied to estimate the transformer tap position for the first time in an unbalanced three-phase distribution network model. The results on 129 bus system model have demonstrated that the OO method can generate a reliable estimate for transformer exact tap position with discrete variables in distribution system SE and also in short period of time. In this paper, the node voltages and power losses are calculated for 129 bus network. It is also demonstrated that OO is much faster than other accurate methods such hybrid particle swarm optimization. The losses obtained with OO are much accurate. In view of this, OO performs better than weighted least square as it provides higher accuracy of the loss calculation. In a distribution network where about 5–6% of electricity generated is lost, accurate estimation of this loss has significant technical and commercial value. The authors believe the technique proposed will help realize those benefits.
TL;DR: In this paper, the authors model part of a public transport network (PTN), specifically, a bus route, as a small-size multi-agent system (MAS) and apply it to a case study considering a real world bus line within the PTN in Auckland, New Zealand.
Abstract: This paper models part of a public transport network (PTN), specifically, a bus route, as a small-size multi-agent system (MAS). The proposed approach is applied to a case study considering a ‘real world’ bus line within the PTN in Auckland, New Zealand. The MAS-based analysis uses modeling and simulation to examine the characteristics of the observed system – autonomous agents interacting with one another – under different scenarios, considering bus capacity and frequency of service for existing and projected public transport (PT) demand. A simulation model of a bus route is developed, calibrated and validated. Several results are attained, such as when the PT passenger load is not close to bus capacity, this load has no effect on average passenger waiting time at bus stops. The model proposed can be useful to practitioners as a tool to model the interaction between buses and other agents.
TL;DR: In this article, the authors proposed an evaluation framework to guide the selection of an appropriate reliability measure and applied regression analysis to determine the factors that exhibit a statistically significant relationship with transit reliability and speed at both the route and segment levels.
Abstract: Reliability and speed are arguably the most important indicators of surface transit performance for both operators and passengers. They can be influenced by a variety of factors, including service characteristics of bus routes, physical infrastructure, signal settings, traffic conditions and ridership patterns. These factors have often been analyzed individually for their impact on transit reliability or speed. Studies considering more than one factor tend to use one or two transit routes to explore their effects. The study that is the subject of this paper proposed an evaluation framework to guide the selection of an appropriate reliability measure. Regression analysis was applied subsequently to determine the factors that exhibit a statistically significant relationship with transit reliability and speed at both the route and segment levels. Automated vehicle location data of a bus route sample that is representative of the entire bus network in the City of Toronto, Ontario, Canada were used. Features s...
TL;DR: A new photovoltaic (PV) farm is proposed to be integrated in GHARDAIA bus distribution network (Gh-17 bus), the optimal location of this PV farm in the distribution network is studied.
Abstract: A new photovoltaic (PV) farm is proposed to be integrated in GHARDAIA bus distribution network (Gh-17 bus), this paper studies the optimal location of this PV farm in the distribution network. The study is done in IEEE-14 bus then it is validated in Gh-17 bus network, the constraints considered for the choice of the optimal location are the stability margin, power loss and critical clearing time (CCT) in case of line fault. The simulation results are given using the PSAT.
Patent•
25 Jan 2017
TL;DR: In this paper, a star of integration carries integration electronic system, which includes the space-borne computer module, observes and controls module, data transfer module, power control module, and data transmission module are connected.
Abstract: The utility model provides a star of integration carries integration electronic system, it includes that integration electronic unit summation passes the transmitter, the integration electronic unit includes the spaceborne computer module, observes and controls module, data transfer module, power control module, the spaceborne computer module includes star affair administrative unit, gesture and orbit controlling unit and thermistor( -ter) reason unit, it is connected with the spaceborne computer module through bus network respectively to observe and control module, data transfer module, power control module, power control module passes through bus network and observing and controlling module, data transfer module are connected, data transfer module passes the transmitter with the number and is connected Adopt the technical scheme of the utility model, have advantages such as small, light in weight, function density height, can realize the platform device function of satellite, realize the purpose that the cable reduces, the satellite is miniaturized on the star, can satisfy well low orbit, long -life, highly reliable, the satellite task requirement more than the 100kg level
TL;DR: The previously proposed synthetic power grid modeling has been enhanced with a direct search procedure for the best bus type assignments in a specific N -bus grid topology, saving the mandatory, but most of the time unattainable, requirement of a set of realistic grid data with a comparable network size for identifying the search target.
Abstract: This paper presents our study results on the correlated assignment of generation, load, or connection buses in a given grid topology and the development of an optimized search algorithm to improve the proposed synthetic grid model, called RT-nestedSmallWorld . A numerical measure, called “bus type entropy”, was proposed in an initial study on this subject to characterize the correlation of bus type assignments in realistic grids. In this paper, its definition has been redefined and improved with the help of some newly obtained data of realistic grids so that the scaling property of a real-world grid's entropy value versus the network size can be effectively captured with a curve-fitting approach. With the help of the derived scaling function, we will be able to determine an appropriate target entropy value that a correlated bus type assignment should assume in a specific N -bus grid network. Therefore, our previously proposed synthetic power grid modeling has been enhanced with a direct search procedure for the best bus type assignments in a specific N -bus grid topology, saving the mandatory, but most of the time unattainable, requirement of a set of realistic grid data with a comparable network size for identifying the search target. Finally, the performance of the proposed approach is examined based on some available grid data including the IEEE test cases, the NYISO-2935, the ERCOT-5633, and the WECC-16994 systems.
01 Jan 2017
TL;DR: A mandatory BLIP lane-changing rule is developed to analyze special asymmetric lane- changing behaviors and setting conditions for deployment of BLIP under the V2V environment such as reasonable departure interval, clear distance, and traffic density are obtained.
Abstract: Bus lane with intermittent priority (BLIP) is an innovative method to improve the reliability of bus services while promoting efficient usage of road resources. Vehicle-to-vehicle (V2V) communication is an advanced technology that can greatly enhance the vehicle mobility, improve traffic safety, and alleviate traffic jams. To explore the benefits of BLIP operation under a connected environment, this study proposed a three-lane cellular automata (CA) model under opening boundary condition. In particular, a mandatory BLIP lane-changing rule is developed to analyze special asymmetric lane-changing behaviors. To improve the simulation accuracy, a smaller cell size is used in the CA model. Through massive numerical simulations, the benefits and influences of BLIP are explored in this paper. They include impacts on neighborhood lanes such as traffic density increasing and average speed decreasing, lane-changing behaviors, lane usage, and the impacts of bus departure interval and clear distance on the road capacity of BLIP. Analysis of traffic flow characteristics of BLIP reveals that there is a strong relationship among bus departure interval, clear distance, and road capacity. Furthermore, setting conditions for deployment of BLIP under the V2V environment such as reasonable departure interval, clear distance, and traffic density are obtained.
TL;DR: The results of the analysis showed that both the data model of the bus network and classifying runs into time periods affect the accuracy of predictions of bus arrival times at bus stops.
TL;DR: In this article, an interdisciplinary approach was applied to the bus network of an urban public transport provider to evaluate the local environmental relief potential of electric busses, and the results showed that due to their specific line characteristics and the frequency of service, two bus lines out of 28 are particularly suitable for the introduction of electromobility in Dresden, Germany.
Abstract: The urban transport sector offers a noteworthy potential for the reduction of national greenhouse gas emissions as well as local pollutant emissions such as nitrogen oxides and particulate matter if electric drive systems are increasingly used. Owing to the fact that electric busses are still in the development phase, higher investment costs have evolved for public transport providers. Hence, decision making about where to introduce electric bus lines is mainly characterized by economic as well as technological considerations. The integration of local or regional ecological aspects is often neglected. An interdisciplinary approach was applied to the bus network of an urban public transport provider. By combining spatial-analytical techniques and statistical methods, the local environmental relief potential of electric busses has been evaluated. The results show that due to their specific line characteristics and the frequency of service, two bus lines out of 28 are particularly suitable for the introduction of electromobility in Dresden, Germany. The presented scientific work contributes to the extension of environmental assessments and decision making tools by including the spatial dimension of environmental impacts. It increases the practical relevance, especially for management decisions of political and entrepreneurial stakeholders by providing a sensible decision basis for local or regional infrastructure projects.
TL;DR: A theoretical framework that provides the basic link between structural controllability of network systems and the topology design problem is developed and the results shed light on how new nodes can be added to the network system without having to introduce new control nodes.
Abstract: In network systems with a huge number of nodes, it is not possible to apply input signals to all network nodes to control them. In this paper, we show that this issue can be addressed by designing a network topology so that the nodes in the network system are controllable by a few nodes in the system. A theoretical framework that provides the basic link between structural controllability of network systems and the topology design problem is developed. The results also shed light on how new nodes can be added to the network system without having to introduce new control nodes. Hence, the results are useful in dealing with topology design to obtain a controllable network. Moreover, the results also show under what circumstances a network system with multiple identical nodes is uncontrollable. In many applications, groups of identical nodes are connected to each other which is called network of groups. Here, we address the structural controllability problem for multiple groups of network systems which provides information on proper topology design at both network level (i.e., interconnection of groups) and node level (i.e., interconnection of nodes within a group).
01 Dec 2017
TL;DR: The entire system simulation shows that voltage stability of the system is getting improved and power flow through the system with UPFC is enhanced.
Abstract: The power system is overwhelmed with the load demand during peak hours. The Flexible AC Transmission Systems (FACTS) have better control on the power flow in an interconnected system. Unified Power Flow Controller (UPFC) is a FACTS device can improve the control of power flow in a transmission system. The IEEE 5 bus network is a benchmark system taken in this paper in order to check the response of UPFC on the power flow enhancement. UPFC is modeled in different ways to analyze power flow and voltage improvement at each bus. In this paper UPFC is modeled as a Voltage Source Model (VSM) and that will generate reference bus voltage and phase angle at different load conditions on the receiving end of UPFC. The variation between the voltage generated by VSM and actual voltage profile in the bus is injected in the line through an injection transformer. The entire system simulation shows that voltage stability of the system is getting improved and power flow through the system with UPFC is enhanced.
TL;DR: In this article, the authors study patterns of entry and exit in the German interurban bus industry in the first three years after its deregulation in January 2013 and find that the industry grew much quicker than originally expected, with particularly new entrants being most successful in quickly extending their route networks from regional to national coverage.
TL;DR: This combinatorial optimization problem is formulated in the form of a multi-objective bi-level programming model that minimizes system travel time, total pollutant emission, and bus operating cost simultaneously simultaneously.
Abstract: Transit priority is considered as an effective way to relieve traffic congestion. As an efficient measure of executing transit priority, the exclusive bus lane design problem has become a research ...
16 May 2017
TL;DR: This paper proposes to study the worst-case delay performance of IEC 61850-9-2 process bus networks, which generally carry non-feedforward traffic patterns, through the combination of measurements and network-calculus-based analysis.
Abstract: In power substation automation systems (SASs) based on IEC 61850, conventional hardwired process connections are being replaced by switched Ethernet To ensure system reliability and responsiveness, transmission of critical information required by protection and control tasks must satisfy hard delay constraints at all times Therefore, delay performance conformance should be taken into consideration during the design phase of an SAS project In this paper, we propose to study the worst-case delay performance of IEC 61850-9-2 process bus networks, which generally carry non-feedforward traffic patterns, through the combination of measurements and network-calculus-based analysis As an Ethernet switch supports dedicated interconnections between its multiple interfaces, our proposed approach converts a non-feedforward network into feedforward ones by introducing service models for its individual output interfaces instead of modeling it in its entirety with a single service model To derive practical delay bounds that can be validated against measurement results, our approach not only constructs traffic models based on the idiosyncrasies of process bus network and switched Ethernet, but also establishes service models of networking devices by taking measurements Results from our case studies of both feedforward and non-feedforward process bus networks show that the proposed combination of network calculus and measurement-based modeling generates accurate delay bounds for Ethernet-based substation communication networks (SCNs) The proposed approach can thus be adopted by designers and architects to analytically evaluate worst-case delay performance at miscellaneous stages of SAS design
TL;DR: A mixed logical dynamical model of a single loop bus transport system which involves both continuous and binary states is proposed, and a hybrid model predictive control scheme with actuation via bus speeds is developed, which can regularize headways and improve bus service quality.