Showing papers on "Bus network published in 2012"

Synchronization of bus timetabling

Abstract: Timetable generation is a subproblem of bus network strategic planning, in which the departure time of each trip is determined. We study the bus network of Monterrey, Mexico, which is similar to those of other cities in Latin America. It is a large bus network where passenger transfers must be favored, almost evenly spaced departures are sought, and bus bunching of different lines must be avoided. We formulate the timetabling problem of this network with the objective of maximizing the number of synchronizations to facilitate passenger transfers and avoid bus bunching along the network. We define these synchronizations as the arrivals of two trips with a separation time within a time window to make a flexible formulation. This flexibility is a critical aspect for the bus network, since travel times vary because of reasons such as driver speed, traffic congestion, and accidents. By proving that our problem is NP-hard we answer a 10-year-old open question about the NP-hardness of similar problems present in literature. Next, we analyze the structural properties of the feasible solution space of our model. This analysis leads to a preprocessing stage that eliminates numerous decision variables and constraints. Moreover, this preprocessing defines feasible synchronization and arrival time windows that are used in a new metaheuristic algorithm. Empirical experimentation shows that our proposed algorithm obtains high-quality solutions for real-size instances in less than one minute.

Transit network design: A procedure and an application to a large urban area

Abstract: This paper describes a procedure for solving the bus network design problem and its application in a large urban area (the city of Rome), characterized by: (a) a complex road network topology; (b) a multimodal public transport system (rapid rail transit system, buses and tramways lines); (c) a many-to-many transit demand. The solving procedure consists of a set of heuristics, which includes a first routine for the route generation based on the flow concentration process and a parallel genetic algorithm for finding a sub-optimal set of routes with the associated frequencies. The final goal of the research is to develop an operative tool to support the mobility agency of Rome for the bus network design phase.

Hybrid Evolutionary Metaheuristics for Concurrent Multi-Objective Design of Urban Road and Public Transit Networks

Abstract: This paper addresses a bi-modal multi-objective discrete urban road network design problem with automobile and bus flow interaction. The problem considers the concurrent urban road and bus network design in which the authorities play a major role in designing bus network topology. The road network design deals with the decision making for new street constructions, lane additions to existing streets, lane allocations for two-way streets, and the orientations and locations of one-way streets. The bus network design is performed by keeping the terminal stations of the existing bus lines unchanged and redesigning the forth and back routes of each line. Four measures, namely user benefit, the demand coverage of the bus network, the demand share of the bus mode, and the average travel generalized cost of bus passengers, are used to evaluate the network design scenarios. The problem is formulated as a multi-objective optimization model in which a modal-split/assignment model is included to depict the mode and route choice behaviors of travelers. The model is solved by the hybrid genetic algorithm and the hybrid clonal selection algorithm. The performance of these algorithms is presented and investigated by solving a number of test networks.

A bus-following model with an on-line bus station

Abstract: In this paper, we developed a bus-following model with consideration of an on-line bus station based on the properties of each bus’s motion. The numerical results show that the proposed model can qualitatively describe the effects of an on-line bus station on each bus’s motion.

Timely Data Delivery in a Realistic Bus Network

Abstract: WiFi-enabled buses and stops may form the backbone of a metropolitan delay-tolerant network, which exploits nearby communications, temporary storage at stops, and predictable bus mobility to deliver non-real-time information. This paper studies the routing problem in such a network. Assuming that the bus schedule is known, we maximize the delivery probability by a given deadline for each packet. Our approach takes the randomness into account, which stems from road traffic conditions, passengers boarding and alighting, and other factors that affect bus mobility. In this sense, this paper is one of the first to tackle quasi-deterministic mobility scenarios. We propose a simple stochastic model for bus arrivals at stops, supported by a study of real-life traces collected in a large urban network. A succinct graph representation of this model allows us to devise an optimal (under our model) single-copy routing algorithm and then extend it to cases where several copies of the same data are permitted. Through an extensive simulation study, we compare the optimal routing algorithm with three other approaches: 1) minimizing the expected traversal time over our graph; 2) maximizing the delivery probability over an infinite time-horizon; and 3) a recently proposed heuristic based on bus frequencies. We show that our optimal algorithm shows the best performance, but it essentially reduces to minimizing the expected traversal time. When transmissions frequently fail (more than half of the times), the algorithm behaves similarly to a heuristic that maximizes the delivery probability over an infinite time horizon. For reliable transmissions and values of deadlines close to the expected delivery time, the multicopy extension requires only ten copies to almost reach the performance of the costly flooding approach.

Hybrid Artificial Bee Colony Algorithm for Transit Network Design

Abstract: A hybrid enhanced artificial bee colony algorithm (HEABC) is proposed for solving the problem of bus network design. The algorithm is intended to reduce the weighted sum of the number of transfers and the total travel time of the users through restructured bus routes and new frequencies without increased fleet sizes. The HEABC relies mainly on the enhanced artificial bee colony algorithm to determine the route structure, and the frequency is determined by the frequency-setting heuristic during the fitness evaluation. For an illustration of its performance, the HEABC was compared with a hybrid generic algorithm and a variant of the HEABC. The results indicated that the HEABC could produce better solutions than the other two algorithms could. Moreover, the HEABC could produce a design that was better than the existing design for maximum intermediate stops, total travel time, number of transfers, maximum headway, and total fuel cost. The design should be acceptable to the public and to bus operators.

Two-wire communication system for high-speed data and power distribution

Abstract: Various embodiments of the present invention provide a two-wire (e.g., unshielded twisted pair) bus system that is simple (e.g., no microcontroller required in slave devices), synchronous with embedded clock information, inexpensive, automotive EMC compliant, and has sufficient speed and bandwidth for a large number of slave devices/peripherals, and also provides various protocols that can be used in various communication systems such as a two-wire bus system. The two-wire bus optionally may be self-powered, i.e., the master device may provide power to the slave devices over the two-wire bus. Various embodiments of the present invention methods for discovery, configuration, and coordinating data communications between master and slave devices in a communication system. Exemplary embodiments are described with reference to a two-wire point-to-point bus system, although the method can be used in other communication systems. Provisions are included for controlling the sequential powering of the bus and slave devices.

Bus pin reduction and power management

Abstract: A reduced-pin bus system includes a bus having one or more signal lines that are coupled to a bus power supply through a current limiting device. A master unit is coupled to the bus and is arranged to transmit communications across the bus during an active period of the bus and to initiate communications during (and/or at the end of) a quiescent period of the bus. A slave unit is coupled to the bus and is arranged to couple power from the one or more signal lines to a capacitor during the quiescent period of the bus and to consume power from the capacitor during the active period of the bus.

Direct Evaluation of IEC 61850-9-2 Process Bus Network Performance

Abstract: This letter presents a technique to assess the overall network performance of sampled value process buses based on IEC 61850-9-2 using measurements from a single location in the network. The method is based upon the use of Ethernet cards with externally synchronized time stamping, and characteristics of the process bus protocol. The application and utility of the method is demonstrated by measuring latency introduced by Ethernet switches. Network latency can be measured from a single set of captures, rather than comparing source and destination captures. Absolute latency measures will greatly assist the design testing, commissioning and maintenance of these critical data networks.

Topology discovery in a hybrid network

Abstract: Systems and methods provide a discovery protocol allowing nodes that are interested in knowing a network topology to discover other nodes in the network topology. The discovery protocol includes two message types, topology discovery messages and topology query messages. A node issues topology discovery messages upon powering up, at periodic intervals, or upon detecting a change in network topology. The topology discovery messages are broadcast to all nodes on a network and identify the issuing node to the network. A topology query message is sent to a particular node and requests a response from the receiving node regarding the neighboring nodes of the receiving node. The querying node can use the response data to discover other nodes and to send the discovered nodes query messages such that the node can determine a network topology to a desired level of depth within the network.

A bus network design procedure with elastic demand for large urban areas

Abstract: The paper deals with a procedure for solving the bus network design problem with elastic demand in a large urban area and its application in a real context (city of Rome). The solution procedure consists of a set of heuristics, which includes a first routine for route generation based on the flow concentration process and a genetic algorithm for finding a sub-optimal set of routes with the associated frequencies. The design criteria are addressed to develop an intensive rather than extensive bus network in order to improve efficiency, integration among direct routes and effective transfer points that strongly affect service quality and ridership. The performances of the transportation system are estimated on a multimodal network taking into account the elasticity of the demand. The final goal of the research is to develop a design framework aiming at shifting the modal split towards the public transport.

Exploiting Modbus Protocol in Wired and Wireless Multilevel Communication Architecture

Abstract: This paper proposes an architectural improvement for the Modbus RTU protocol to integrate equipments in industrial automation networks, employing hybrid communication with wired Modbus RTU and wireless IEEE 802.15.4. These environments have different electromagnetic interferences, requiring protocols with noise immunity to varied equipments such as motors and generators. Modbus RTU is a simple and robust master-slave protocol that accepts the integration of a master with up to 247 slaves into a bus topology. In addition, the IEEE 802.15.4 protocol emerged recently as a wireless solution to industrial environments since it allows electromagnetic spectrum evaluation, and the choice of avoiding communications in noise frequencies and decreasing the error rate between packets. The proposed hybrid communication protocol increases control and topological limits imposed by Modbus RTU by enabling a wired/wireless tree-bus topology and master multiplexing. Moreover, the academy-industry cooperation resulted in features implemented in a gateway, whose efficiency is evaluated with practical experiments in different topologies.

MWGen: A Mini World Generator

Abstract: Moving objects representing movement in all real world environments (e.g., road network, bus network, indoor) should be managed in a database system, for the reason that a person's trip can cover several environments rather than one. GMOD (Generic Moving Objects Database) is a database system to manage moving objects that (1) travel through different environments, (2) contain multiple transportation modes such as \textit{Car} $\right arrow$ \textit{Walk} $\right arrow$ \textit{Indoor}. To evaluate the performance of GMOD, one needs a comprehensive and scalable dataset consisting of all available environments and moving objects. Due to the difficulty of gaining real datasets, in this paper we present a tool called MWGen that creates the overall space for moving objects, composed of the following environments: road network, bus network, metro network, pavement areas and indoor. Based on roads, all outdoor environments are created. The indoor environment consisting of a set of buildings is established from public floor plans. Moving objects are generated based on trip planning where a navigation algorithm through different environments is developed. We are able to produce moving objects integrated with multiple transportation modes. In addition, trip planning in a single environment is also available, e.g., shortest path for pedestrians, indoor navigation. The generated data, including all infrastructures and moving objects, are managed by GMOD. We conduct an extensive performance study to evaluate MWGen on two real road datasets and a set of public floor plans.

The design of interurban bus networks in city centers

Abstract: This paper proposes a bilevel formulation for solving the Bus Network Design Problem (BNDP) of interurban services entering a major city. It is focused in interurban services because it is a growing problem in most of major cities, yet new in the literature. The layout of interurban bus routes and the locations of transfer stations in the main city are the key factors to provide a competitive public transportation service to commuters in a metropolitan area. The number of commuters in huge urban concentrations is growing due to the difficulties of living near the city center. The objective function of the first level is defined with the aim of reducing user and agency costs. In the second level the performance of users is addressed. Furthermore, a local search method based on the Tabu Search algorithm was carried out to guide the exploration in the solution domain. The results obtained in a set of test problems have demonstrated that the restart parameters of the algorithm play a significant role in the efficiency of the algorithm. Finally, implementation in the large network of Barcelona (Spain) reduces the total cost by 5% with regard to the present situation.

Bus clock frequency scaling for a bus interconnect and related devices, systems, and methods

Abstract: Bus clock frequency scaling for a bus interconnect and related devices, systems, and methods are disclosed. In one embodiment, the bus interconnect comprises an interconnect network configurable to connect a master port(s) to a slave port(s). A bus interconnect clock signal clocks the interconnect network. The controller is configured to receive bandwidth information related to traffic communicated over the master port(s) and the slave port(s). The controller is further configured to scale (e.g., increase or decrease) the frequency of the bus interconnect clock signal if the bandwidth of the master port(s) and/or the slave port(s) meets respective bandwidth condition(s), and/or if the latency of the master port(s) meets a respective latency condition(s) for the master port(s). The master port(s) and/or slave port(s) can also be reconfigured in response to a change in frequency of the bus interconnect clock signal to optimize performance and conserve power.

Network storage target boot and network connectivity through a common network device

Abstract: The present disclosure includes systems and techniques relating to booting to a network storage target In general, in one implementation, a bus-to-network device driver is loaded during a machine boot, where the bus-to-network device driver is capable of sending machine bus commands over a network, providing access to the network for a network device driver, and distinguishing between received responses to the machine bus commands and other network traffic corresponding to the network device driver Loading of the bus-to-network device driver can occur in response to an operating system load of bus drivers For example, the bus-to-network device driver can be an iSCSI driver, and the operating system load of bus drivers can be the operating system load of SCSI drivers

Optimizing power usage by processor cores based on architectural events

Abstract: A method and apparatus to monitor architecture events is disclosed The architecture events are linked together via a push bus mechanism with each architectural event having a designated time slot There is at least one branch of the push bus in each core Each branch of the push bus may monitor one core with all the architectural events All the data collected from the events by the push bus is then sent to a power control unit

Real Time Bus Monitoring System Using GPS

Abstract: The Real Time Bus Monitoring and Passenger Information bus tracking device will serve as a viable notification system that will effectively assist pedestrians in making the decision of whether to wait for the bus or walk. This device is a standalone system designed to display the real-time location(s) of the buses in Mumbai city. The system will consist of a transmitter module installed on the buses, receiver boards installed on the bus stops, LED embedded map of the BEST bus transportation routes at the centralized controller. It will also have passenger information system software installed at the bus stops and which will provide user the relevant information regarding all the bus numbers going for his source to destination along with the route details and the cost. Assembly of these modules will enable the tracking device to obtain GPS data of the bus locations, which will then transfer it to centralized control unit and depict it by activating LEDs in the approximate geographic positions of the buses on the route map. It will also transmit its bus numbers and route names continuously as soon as the bus comes within the range of the receiver at the bus stop. In addition, the device will be portable and sustainable; it will not require an external power source, which will eliminate long-term energy costs.

CAN (Controller Area Network) and LIN (Local Interconnect Network) bus network based vehicle control system

Abstract: The invention discloses a CAN (Controller Area Network) and LIN (Local Interconnect Network) bus network based vehicle control system which comprises a local area network connecting all electric control units in the vehicle control system, wherein all the electric control units communicate with one another through the local area network. The local area network comprises a power high-speed CAN, a vehicle body high-speed CAN, a first LIN and a second LIN. In the invention, A double-high-speed CAN and two-LIN topological structure is adopted, and reasonable nodes with terminal resistors are used, therefore the expansibility of the whole network is strengthened; timeliness of the network is improved through the definition of ID, cycle and the like; the wakeup from sleep of the whole network is ensured through the application of complicated network management, therefore the effect of coordinative and orderly network operation can be achieved.

Hierarchical Network-on-Chip and Traffic Compression for Spiking Neural Network Implementations

Abstract: The complexity of inter-neuron connectivity is prohibiting scalable hardware implementations of spiking neural networks (SNNs). Traditional neuron interconnect using a shared bus topology is not scalable due to non-linear growth of neuron connections with the neural network size. This paper presents a novel hierarchical NoC (H-NoC) architecture for SNN hardware which addresses the scalability issue by creating a 3-dimensional array of clusters of neurons with a hierarchical structure of low and high-level routers. The H-NoC architecture also incorporates a spike traffic compression technique to exploit SNN traffic patterns, thus reducing traffic overhead and improving throughput on the network. In addition, adaptive routing capabilities between clusters balance local and global traffic loads to sustain throughput under bursting activity. Simulation results show a high throughput per cluster (3.33x109 spikes/second), and synthesis results using 65-nm CMOS technology demonstrate low cost area (0.587mm2) and power consumption (13.16mW @100MHz) for a single cluster of 400 neurons, which outperforms existing SNN hardware strategies.

D-BUS high-speed bus technology based on ring type Ethernet and auxiliary network

Abstract: The invention provides a D-BUS high-speed bus technology based on a ring type Ethernet and an auxiliary network, which belongs to the technical field of industrial control. The D-BUS high-speed bus technology is characterized in that a D-BUS (Dual-BUS) high-speed bus network consists of a high-speed ring type Ethernet ReBUS and an auxiliary network MB+, wherein the ReBUS bus utilizes the physical layer specification of Ethernet IEEE802.3, a main station is connected with slave stations in series to form a ring type topological structure, the wiring mode for the main station and the slave stations is same with that of the slave stations with the slave stations, a receiving terminal of each equipment is connected with a transmitting terminal of the former equipment, the transmitting terminal of the equipment is connected with a receiving end of a latter terminal, the receiving terminals are sequentially connected with the transmitting terminals in the mode to form a ring type network structure, I/O equipment are connected with the slave stations through RS485 serial ports and serve as the expansion I/O of the slave stations, and failure detection comprising failure diagnosis, failure location and communication redundancy is realized by the MB+ bus. The invention has the beneficial effects that the ring type wiring cost is low, the data exchange of all network nodes is realized by one message, the communication efficiency is high, a failure detection and failure recovery mechanism is provided, and the reliability is high.

Bus signal priority strategies for Multi-directional bus routes

Abstract: Though the Bus Signal Priority (BSP) system is well known as an effective way to enhance the service quality of bus travel, the effectiveness of the BSP system significantly depends on the traffic and network conditions. Particularly, most previous use of the BSP system were applied as a corridor-based strategy targeting a few bus lines moving on a corridor; hence existing BSP systems cannot guarantee the service quality of all of the buses in a complex and congested network conflicted by numerous bus lines. Therefore, an appropriate signal priority strategy should be identified before the introduction of a BSP system according to the network conditions. As an alternative to the corridor-based signal priority strategy, this study proposes a Multi-directional Bus Signal Priority (MBSP) approach and analyzes the effectiveness of different priority strategies given various network conditions using the simulation tool Paramics. In addition, to manage conflicting and competing requests, a priority-based rule is proposed and compared with the First-In-First-Service (FIFS) rule. The simulation results showed that a corridor-based BSP was effective for a concentrated bus network, whereas it might deteriorate other traffic flows with little improvement of the bus service for a diverse bus network. For a diverse bus network, other strategies apart from the priority-based MBSP strategy cannot be expected to improve the reliability of bus service.

Managing and revoking power allocated through bus interfaces

Abstract: The disclosed embodiments provide a system that manages power allocated through a set of bus interfaces on a computer system. During operation, the system obtains a first request for revocable current beyond a reserved current for a first bus interface from the set of bus interfaces, wherein the request is associated with a first device connected to the first bus interface. Next, the system allocates the revocable current to the first bus interface from an extra-current budget for the set of bus interfaces. Upon detecting a connection of a second device that requires non-revocable current over the extra-current budget to a second bus interface from the set of bus interfaces, the system transmits a first notification to the first device to relinquish the revocable current. Finally, the system allocates the non-revocable current to the second device from the relinquished revocable current.

Communication method, communication system, and energy storage system including the same

Abstract: There is provided a battery system including a system bus, a system controller coupled to the system bus and configured to transmit one or more first system frames on the system bus, and one or more battery subsystems coupled to the system bus and configured to transmit one or more second system frames on the system bus, wherein at least one of the one or more battery subsystems including a storage system for storing power, and a storage system controller for controlling charging and discharging of the storage system, for receiving storage system data, and for transmitting the one or more second system frames including the storage system data on the system bus, wherein at least one of the system controller or the storage system controller is configured to apply a system frame division signal on the system bus between the system frames.

New method for monitoring voltage stability condition of a bus of an interconnected power system using measurements of the bus variables

Abstract: The study presents a new method for monitoring the voltage stability condition of a bus using measurements of the bus variables. For this purpose, bus real power, bus reactive power and bus voltage of a target/selected bus have to be measured (sampled) for two consecutive time frames. These measured values are used to monitor the voltage stability condition of a bus using the mathematical basis developed in this study. The validity and applicability of the proposed method has been established through simulation on IEEE 30 and IEEE 118 bus system.

Clustering and association rules in analyzing the efficiency of maintenance system of an urban bus network

Abstract: Maintenance has always been considered as an important part of both manufacturing and service systems and yet a costly practice. The purpose of this study is to analyze the efficiency of the maintenance activities in a maintenance system comprising of independent components, using the collected data in process. For this purpose, a three-stage method was followed. First, at the initial data preprocessing stage, after the data purification, new operating fields were defined. The data was integrated in a final matrix which was used as an input for the modeling phase. At this stage, using one of the clustering algorithms i.e. k-means, the maintenance data was clustered so that homogenous clusters of the components i.e. buses, were formed. Then using the Euclidean distance, the distances of the clusters from the ideal status were found and clusters were categorized and named accordingly. In the last part of the modeling stage, while having the clusters as target, Apriori algorithm was used to identify the rules (conditions) which had caused each record to be placed in each specific cluster and thereby to find a way to assess the efficiency of the maintenance system and activities. At the 3rd stage and on the basis of the extracted rules, necessary steps were proposed to eliminate the conditions which lead records to be placed in the clusters comprising records of bad conditions. The method is explained in a case study of the maintenance system of an urban transportation bus network.

Optimisation of a Bus Network Configuration and Frequency Considering the Common Lines Problem

Abstract: Public transportation network reorganisation can be a key measure in designing more efficient networks and increasing the number of passengers To date, several authors have proposed models for the “transit route network design problem” (TRNDP), and many of them use a transit assignment model as one component However, not all models have considered the “common lines problem,” which is an essential feature in transit network assignment and is based on the concept that the fastest way to get to a destination is to take the first vehicle arriving among an “attractive” set of lines Thus, we sought to reveal the features of considering the common lines problem by comparing results with and without considering the problem in a transit assignment model For comparison, a model similar to a previous one was used, formulated as a bi-level optimisation problem, the upper problem of which is described as a multi-objective problem As a result, although the solutions with and without considering the common lines showed almost the same Pareto front, we confirmed that a more direct service is provided if the common lines problem is considered whereas a less direct service is provided if it is not With a small network case study, we found that considering the common lines problem in the TRNDP is important as it allows operators to provide more direct services