Showing papers on "Bus network published in 2014"

Enhancing metro network resilience via localized integration with bus services

Abstract: This paper advances the field of network disruption analysis by introducing an application to a multi-modal transport network, capitalizing on the redundancies and improved connectivity of an integrated metro-bus network. Metro network resilience to disruptions can be enhanced by leveraging on public bus services. To ensure better acceptance among operators and commuters, we focus on introducing localized integration with bus services instead of designing an entirely new bus network to achieve the desired resilience to potential disruptions. This is accomplished by increasing the capacity of bus services that run in parallel with affected metro lines as well as those connecting to different metro lines. Our analysis starts with a network representation to model the integrated metro and bus system. A two-stage stochastic programming model is further developed to assess the intrinsic metro network resilience as well as to optimize the localized integration with bus services. The approach is applied to a case study based on the Singapore public transit system and actual travel demand data. The results show that the metro network resilience to disruptions can be enhanced significantly from localized integration with public bus services.

Network device and network system

Abstract: A network device connected via a bus with a plurality of network devices includes: an authentication unit that executes authentication based upon message authentication information included in data transmitted, via the bus, by one of the plurality of network devices acting as a sender device; and a processing unit that invalidates the data upon determining that unauthorized data have been transmitted by the sender device impersonating another network device among the plurality of network devices if the authentication fails.

Solving a discrete multimodal transportation network design problem

Abstract: This paper investigates the multimodal network design problem (MMNDP) that optimizes the auto network expansion scheme and bus network design scheme in an integrated manner. The problem is formulated as a single-level mathematical program with complementarity constraints (MPCC). The decision variables, including the expanded capacity of auto links, the layout of bus routes, the fare levels and the route frequencies, are transformed into multiple sets of binary variables. The layout of transit routes is explicitly modeled using an alternative approach by introducing a set of complementarity constraints. The congestion interaction among different travel modes is captured by an asymmetric multimodal user equilibrium problem (MUE). An active-set algorithm is employed to deal with the MPCC, by sequentially solving a relaxed MMNDP and a scheme updating problem. Numerical tests on nine-node and Sioux Falls networks are performed to demonstrate the proposed model and algorithm.

Continuum approximation approach to bus network design under spatially heterogeneous demand

Abstract: A methodological framework is formulated so that continuum approximation techniques can be used to design bus networks for cities where travel demand varies gradually over space. The bus-route configurations that result consist of (i) a main, possibly city-wide grid with relatively large physical spacings between its parallel routes and the stops along those routes; together with (ii) one or more local grids with more closely-spaced routes and stops that serve neighborhoods of higher demand densities. The so-called power-of-two concept is borrowed from the field of inventory control, and is enforced so that local grids can be inserted seamlessly within the main one. The resulting heterogeneous route configurations can reduce the costs to the bus users and the operating agency combined, as compared against the costs of homogeneous bus-route grids. Differences of as much as 8% are observed for numerical examples that cover wide-ranging patterns in spatially-varying demand. Much of the savings are due to the diminished access costs that users enjoy when high-demand neighborhoods are served by local grids with closely-spaced routes and stops.

Asymmetrical universal serial bus communications

Abstract: In some embodiments a Universal Serial Bus cable includes a first differential pair to transmit bus signals, and a second differential pair to transmit bus signals in a same direction as the bus signals transmitted by the first differential pair. In this manner, a bandwidth of the Universal Serial Bus cable is doubled in that same direction. Other embodiments are described and claimed.

System-Level Tests of Transformer Differential Protection Using an IEC 61850 Process Bus

Abstract: The IEC 61850 family of standards for substation communication systems was released in the early 2000s and includes IEC 61850-8-1 and IEC 61850-9-2 that enable Ethernet to be used for process-level connections between transmission substation switchyards and control rooms. This paper presents an investigation of process bus protection performance, since the inservice behavior of multifunction process buses is largely unknown. An experimental approach was adopted that used a Real Time Digital Simulator and “live” substation automation devices. The effect of sampling synchronization error and network traffic on transformer differential protection performance was assessed and compared to conventional hard-wired connections. Ethernet was used for all sampled value measurements, circuit breaker tripping, transformer tap-changer position reports, and precision time protocol synchronization of sampled value merging unit sampling. Test results showed that the protection relay under investigation operated correctly with process bus network traffic approaching 100% capacity. The protection system was not adversely affected by synchronizing errors significantly larger than the standards permit, suggesting that these requirements may be overly conservative. This “closed loop” approach, using substation automation hardware, validated the operation of protection relays under extreme conditions. Digital connections using a single shared Ethernet network outperformed conventional hard-wired solutions.

Designing large-scale bus network with seasonal variations of demand

Abstract: Creating a bus network that covers passenger demand conveniently is an important ingredient of the transit operations planning process. Certainly determination of optimal bus network is highly sensitive to any change of demand, thus it is desirable not to consider average or estimated figures, but to take into account prudently the variations of the demand. Many cities worldwide experience seasonal demand variations which naturally have impact on the convenience and optimality of the transit service. That is, the bus network should provide convenient service across all seasons. This issue, addressed in this work, has not been thoroughly dealt with neither in practice nor in the literature. Analyzing seasonal transit demand variations increases further the computational complexity of the bus-network design problem which is known as a NP-hard problem. A solution procedure using genetic algorithm efficiently, with a defined objective-function to attain the optimization, is proposed to solve this cumbersome problem. The method developed is applied to two benchmarked networks and to a case study, to the city of Mashhad in Iran with over 3.2 million residents and 20 million visitors annually. The case study, characterized by a significant seasonal demand variation, demonstrates how to find the best single network of bus routes to suit the fluctuations of the annual passenger demand. The results of comparing the proposed algorithm to previously developed algorithms show that the new development outperforms the other methods between 1% and 9% in terms of the objective function values.

System and method for mapping a service-level topology to a service-specific data plane logical topology

Abstract: An embodiment method includes receiving service parameters for a service and locating logical network nodes for a service-specific data plane logical topology at respective physical network nodes among a plurality of physical network nodes according to the service parameters, a service-level topology, and a physical infrastructure of the plurality of physical network nodes. The method also includes defining connections among the logical network nodes according to the service parameters, the service-level topology, and the physical infrastructure, and defining respective connections for a plurality of UEs to at least one of the logical network nodes according to the service parameters, the service-level topology, and the physical infrastructure. The method further includes defining respective functionalities for the logical network nodes.

Point-to-multipoint path computation for wide area network optimization

Abstract: In some examples, a controller for a network includes a path computation module configured for execution by one or more processors to obtain configuration information for at least one point-to-multipoint label switched path (P2MP LSP); obtain, from the network via at least one protocol, network topology information defining a network topology for the network; determine, based on the network topology, a first solution comprising first respective paths through the network for the at least one P2MP LSP; determine, after generating a modified network topology based on the network topology, a second solution comprising second respective paths through the network for the at least one P2MP LSP. The controller also includes a path provisioning module configured for execution by the one or more processors to configure the network with the solution of the first solution and the second solution having the lowest total cost.

Variable bus stops across a bus route in a regional transportation network

Abstract: Disclosed are a method and a system of variable bus stops across a bus route in a regional transportation network, according to one embodiment. A method of a bus server includes analyzing a current geospatial location of a mobile device responsive to a pick up request of a prospective bus passenger, associating a closest street intersection with the current geospatial location of the mobile device, and determining if a bus route traverses the closest street intersection associated with the current geospatial location of the mobile device. A message may be communicated to the mobile device based on the determination of whether the bus route traverses the closest street intersection. A bus associated with the bus route may be instructed to pick up the prospective bus passenger when the bus route traverses the closest street intersection associated with the current geospatial location of the mobile device.

Information dissemination in a multi-technology communication network

Abstract: A method for information dissemination in a multi-technology communication network wherein network nodes are equipped with first communication means for operating via a long range communication network and with second communication means for performing short-range communication includes performing, by a central entity, the steps of determining coverage areas of the network nodes; establishing dissimilarity relations between network nodes with respect to the coverage areas of the network nodes such that a dissimilarity relation index value is larger for two network nodes covering less similar areas; and selecting, subject to configurable constraints, network nodes with a highest dissimilarity relation index value as mobile infrastructure nodes that are intended to act as relay and/or forwarder nodes for supporting optimal information penetration in a given destination dissemination area.

Power-line communication coupling

Abstract: In some embodiments, a system includes a power system coupled to a power bus, and a power line communication (PLC) gateway coupled in series with the power bus. In other embodiments, a system includes first and second power circuits coupled in series with a power bus, and first and second power-line communication circuits coupled in series with the power bus. In additional embodiments, a system includes a power converter coupled to a power bus and having one or more switching frequencies, and a power-line communication circuit coupled to the power bus and having one or more communication frequencies, where at least one of the switching frequencies is substantially greater than at least one of the communication frequencies.

Methods and systems for server power line communication

Abstract: A server system includes a common power bus, a power supply to provide direct current (DC) power through the common power bus, at least one node including a processor to receive the DC power through the common power bus, a transmitter capacitive coupled to the common power bus to transmit a power information signal from the power supply through the common power bus, and at least one receiver capacitive coupled to the common power bus to receive the power information signal transmitted by the transmitter and to provide the received power information signal to the at least one node. A plurality of buffers respectively coupled between the common power bus and each of the power supply and the at least one node provide path separation for high frequency and low frequency currents.

Hybrid Method for Bus Network Design with High Seasonal Demand Variation

Abstract: Seasonal demand variation is a somewhat neglected aspect of transit demand. Many cities worldwide experience seasonal variation of passenger demand that deserves not only changes of service frequency, but also and often more importantly, changes in the transit network of routes. Literature dealing with optimal bus networks shows that it is an non polynomial (NP)-hard complexity problem with the demand being the most important variable affecting the network. Thus, the bus network of concern should be robust from the optimization perspective when a new demand arises. This paper introduces a model and a solution algorithm to take into account the variation of passenger demand in the design of bus networks. The solution algorithm developed is a hybrid method that optimizes the design of a bus network at the route and network levels. The model was applied to the city of Mashhad in Iran with a population of over 3.2 million and 20 million visitors annually. The results are promising and demonstrate how ...

Smart, public buses information system

Abstract: Lack of appropriate information system for transportation, particularly for passengers who use public transport, specifically buses for commuting is causing lot of anxiety among the commuter. Passengers wait for long time at the bus terminus expecting the bus to arrive as per the schedule. At present there is no such system in place for the benefit of the passengers who take buses for commuting. It would be good to have such a system like in railway stations which provide information about the arriving and departing trains. We propose a system which could track the current position of buses and the dynamic arrival and departure time and inform the passengers via display boards at the terminus or through an App installed in the smart phone. It has a GPS system that tracks the position of a particular bus and the data is transmitted by a GSM modem to the bus terminus. The receiver part of the system which is installed at the bus terminus processes the received data and calculates the arrival time and delay time of a particular bus. The initial testing shows that it will be a boon for the commuters who often meet with boredom and anxiety without knowing when the buses will arrive.

Network topology optimization

Abstract: In some examples, a controller for a multi-layer network comprising a network layer and an underlying transport layer is configured to obtain abstract link data describing a plurality of candidate links; determine, based at least on the abstract link data, a first solution comprising a network topology for the network layer that includes a first selected subset of the candidate links; determine, after generating a modified network topology based at least on the network topology and the abstract link data, a second solution comprising the modified network topology for the network layer that includes a second selected subset of the candidate links; and output, for configuring the multi-layer network, topology data for one of the first solution or the second solution having a lowest total cost, the lowest total cost including a total resource cost to the network for the one of the first solution or the second solution.

Power swtiching in a two-wire conductor system

Abstract: In an example embodiment, a power switching circuit of an automobile audio bus (A 2 B) chip is provided in a bi-directional, multi-node two-wire conductor system that includes a plurality of A 2 B chips interconnected on a twisted wire pair bus (A 2 B bus), with at least one A 2 B chip functioning as a master and the remaining A 2 B chips functioning as slaves. The power switching circuit of the A 2 B chip powers up a next downstream A 2 B chip in the A 2 B bus sequentially according to a power switching procedure, and the power switching circuit is configured to detect faults in the A 2 B bus before, during, and after the power switching procedure. Each A 2 B chip enables power to the next downstream A 2 B chip without risk of damage to any components in the system due to line faults on the downstream A 2 B bus, or collapse of the power supply at the local A 2 B chip.

A Review of Immediate Bus Architecture: A System Perspective

Abstract: Three basic intermediate bus architectures are reviewed for electronic power distribution system and components developers from a system perspective. Salient features for each system are discussed in detail. They cover input power stage, bus voltage level, output power stage, output regulation, multiple outputs, thermal property, system stability, and output impedance. Design tradeoffs are also presented to guide practical designs. It is concluded that the double regulated intermediate bus architecture has the best efficiency, regulation, thermal, and stability performances. Engineering hardware achieved a record efficiency of 99%, validating the superiority of the double regulated intermediate bus architecture.

Method for generating urban bus route network based on segmented splicing

Abstract: The invention discloses a method for generating an urban bus route network based on segmented splicing. The method comprises the following steps that first, urban bus stations are used as network nodes, and a user balancing distribution method is used for acquiring the passage point traffic of all the bus stations; a bus center point determining method is used for acquiring a bus center node set, and a bus network route section set of bus single center nodes among bus center nodes is generated; accordingly, an initial line network generation method is used for setting the departure frequency of all bus routes, and an initial bus line network planning scheme is obtained; then, a simulated annealing algorithm is used for optimization; a novel bus line network planning scheme is formed through a line network adjusting method and a frequency adjusting method every time, and a strategy balancing distribution method based on effective frequencies is used for simulation and evaluation until an optimized urban bus line network is acquired. The method for generating the urban bus route network based on segmented splicing has the advantages that the steps are simplified, the practicability is high, standardized implementation can be achieved, and the planning routes are reasonable and scientific.

Analysis of feeder bus network design and scheduling problems.

Abstract: A growing concern for public transit is its inability to shift passenger's mode from private to public transport. In order to overcome this problem, a more developed feeder bus network and matched schedules will play important roles. The present paper aims to review some of the studies performed on Feeder Bus Network Design and Scheduling Problem (FNDSP) based on three distinctive parts of the FNDSP setup, namely, problem description, problem characteristics, and solution approaches. The problems consist of different subproblems including data preparation, feeder bus network design, route generation, and feeder bus scheduling. Subsequently, descriptive analysis and classification of previous works are presented to highlight the main characteristics and solution methods. Finally, some of the issues and trends for future research are identified. This paper is targeted at dealing with the FNDSP to exhibit strategic and tactical goals and also contributes to the unification of the field which might be a useful complement to the few existing reviews.

Methods for sharing bandwidth across a packetized bus and systems thereof

Abstract: A system, method, and computer readable medium for sharing bandwidth among executing application programs across a packetized bus for packets from multiple DMA channels includes receiving at a network traffic management device first and second network packets from respective first and second DMA channels. The received packets are segmented into respective one or more constituent CPU bus packets. The segmented constituent CPU bus packets are interleaved for transmission across a packetized CPU bus.

A power line communication on DC bus with photovoltaic strings

Abstract: In this paper, an innovative topology performing a Power Line Communication on DC bus, with series connected photovoltaic modules, is presented. The circuit ensures the transmission on the DC bus even if the transceivers cannot share the same reference voltage. Moreover, a circuit solution avoiding that the operating point of the photovoltaic string can be affected is proposed. The circuit is provided with an effective energy harvesting supply stage, which completely eliminates the need for external supply or batteries. Experimental results achieved by means of a commercial power line transceiver demonstrate both robustness and reliability of the proposed topology.

Controller Area Network for fault tolerant small satellite system design

Abstract: The Controller Area Network (CAN) is a message based event triggered communication bus mostly used in the automotive industry. In this paper, however, the CAN bus is tested for being applicable to small satellite systems in order to provide better fault-tolerance. The CAN bus connects several independent CAN modules and allows them to communicate and work together asynchronously and/or synchronously. The CAN modules were designed to decrease weight and cost while improving stability and power consumption compared to current small satellite systems. We present advantages to using the CAN bus over existing satellite bus systems, design and propose a CAN protocol for CubeSats.

Methods and apparatus for multi-drop digital bus

Abstract: Apparatus and methods for digital bus operation, in one embodiment, the digital bus is a bidirectional, time-division multiplexing (TDM) audio bus operation, and a bus technology is described that enables multi-drop (e.g., multiple device, multiple node, etc.) connectivity for real-time audio over a small form factor interface (e.g., as few as two (2) wires). Specifically, an exemplary tri-level signaling scheme provides bidirectional functionality, real-time clock edges, audio data, in a multi-drop topology in one implementation.

Continuum Approximation Approach to Bus Network Design under Spatially Heterogeneous Demand

Abstract: A methodological framework is formulated so that continuum approximation techniques can be used to design bus networks for cities where travel demand varies gradually over space. The bus-route configurations that result consist of (i) a main, possibly city-wide grid with relatively large physical spacings between its parallel routes and the stops along those routes; together with (ii) one or more local grids with more closely-spaced routes and stops that serve neighborhoods of higher demand densities. The so-called power-of-two concept is borrowed from the field of inventory control, and is enforced so that local grids can be inserted seamlessly within the main one. The resulting heterogeneous route configurations can reduce the costs to the bus users and the operating agency combined, as compared against the costs of homogeneous bus-route grids. Differences of as much as 8% are observed for numerical examples that cover wide-ranging patterns in spatially-varying demand. Much of the savings are due to the diminished access costs that users enjoy when high-demand neighborhoods are served by local grids with closely-spaced routes and stops.

A Bus Lane Reservation Problem in Urban Bus Transit Network

Abstract: This work studies a new variant of lane reservation problem called a bus lane reservation problem. It aims to optimally select some road segments to be reserved for buses in a predetermined bus transit network such that bus travelers can be rapidly transited. Two realistic assumptions are made in this work: 1) the total travel time on each bus route should be completed within a given deadline; 2) a lane on a road segment can be reserved for buses only when the bus volume on it exceeds a given level. The former guarantees bus travel time in order to improve the service level of a bus transit system. The second ensures minimum bus utilization on a reserved lane. However, private vehicles are not allowed to pass the bus exclusive lanes. Such a bus lane reservation strategy causes negative traffic impact on private vehicles. The objective of the problem is to minimize the negative traffic impact of reserved lanes. For the problem, the authors first construct an integer linear programming model and demonstrate its complexity to be NP-hard. Then, the authors propose a cut-and-solve algorithm to obtain its optimal solution. The computational results on randomly generated instances show that the proposed method is more efficient than the optimization software CPLEX 12.4.

Increasing security in inter-chip communication

Abstract: An apparatus for increasing security in inter-chip communication includes a sending control module, a communication bus, and a receiving control module. The communication bus is coupled between the sending control module and the receiving control module. The sending control module operates to send data on the communication bus, disable the communication bus when threats are detected, or both.

Encoding for partitioned data bus

Abstract: A data bus (206) is split into partitions (218, 216) and encoding (214, 212) is independently applied to data transmitted over each bus partition to improve power and/or throughput efficiency. The encoding can be data bus inversion or any other suitable type of encoding. An encoding indicator symbol (226) transmitted in conjunction with the data indicates which bus partition is encoded, if any. In some implementations, encoding is selectively applied to each bus partition during each data transfer cycle of a parallel data bus. In some implementation, the encoding indicator symbol is a multi-level signal where each level of the multi-level signal represents at least two bits of information indicative of, for a corresponding bus partition, whether encoding is applied to the data to be transmitted over the bus partition. Advantageously, the encoding indicator symbol can be transmitted over a single, dedicated bus line.