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Sample records for queue dual bus

  1. Study on the Calculation Models of Bus Delay at Bays Using Queueing Theory and Markov Chain

    PubMed Central

    Sun, Li; Sun, Shao-wei; Wang, Dian-hai

    2015-01-01

    Traffic congestion at bus bays has decreased the service efficiency of public transit seriously in China, so it is crucial to systematically study its theory and methods. However, the existing studies lack theoretical model on computing efficiency. Therefore, the calculation models of bus delay at bays are studied. Firstly, the process that buses are delayed at bays is analyzed, and it was found that the delay can be divided into entering delay and exiting delay. Secondly, the queueing models of bus bays are formed, and the equilibrium distribution functions are proposed by applying the embedded Markov chain to the traditional model of queuing theory in the steady state; then the calculation models of entering delay are derived at bays. Thirdly, the exiting delay is studied by using the queueing theory and the gap acceptance theory. Finally, the proposed models are validated using field-measured data, and then the influencing factors are discussed. With these models the delay is easily assessed knowing the characteristics of the dwell time distribution and traffic volume at the curb lane in different locations and different periods. It can provide basis for the efficiency evaluation of bus bays. PMID:25759720

  2. Study on the calculation models of bus delay at bays using queueing theory and Markov chain.

    PubMed

    Sun, Feng; Sun, Li; Sun, Shao-Wei; Wang, Dian-Hai

    2015-01-01

    Traffic congestion at bus bays has decreased the service efficiency of public transit seriously in China, so it is crucial to systematically study its theory and methods. However, the existing studies lack theoretical model on computing efficiency. Therefore, the calculation models of bus delay at bays are studied. Firstly, the process that buses are delayed at bays is analyzed, and it was found that the delay can be divided into entering delay and exiting delay. Secondly, the queueing models of bus bays are formed, and the equilibrium distribution functions are proposed by applying the embedded Markov chain to the traditional model of queuing theory in the steady state; then the calculation models of entering delay are derived at bays. Thirdly, the exiting delay is studied by using the queueing theory and the gap acceptance theory. Finally, the proposed models are validated using field-measured data, and then the influencing factors are discussed. With these models the delay is easily assessed knowing the characteristics of the dwell time distribution and traffic volume at the curb lane in different locations and different periods. It can provide basis for the efficiency evaluation of bus bays. PMID:25759720

  3. Multiclass processes, dual points and M/M/1 queues

    E-print Network

    Pablo A. Ferrari; James B. Martin

    2005-09-20

    We consider the discrete Hammersley-Aldous-Diaconis process (HAD) and the totally asymmetric simple exclusion process (TASEP) in Z. The basic coupling induces a multiclass process which is useful in discussing shock measures and other important properties of the processes. The invariant measures of the multiclass systems are the same for both processes, and can be constructed as the law of the output process of a system of multiclass queues in tandem; the arrival and service processes of the queueing system are a collection of independent Bernoulli product measures. The proof of invariance involves a new coupling between stationary versions of the processes called a multi-line process; this process has a collection of independent Bernoulli product measures as an invariant measure. Some of these results have appeared elsewhere and this paper is partly a review, with some proofs given only in outline. However we emphasize a new approach via dual points: when the graphical construction is used to construct a trajectory of the TASEP or HAD process as a function of a Poisson process in ZxR, the dual points are those which govern the time-reversal of the trajectory. Each line of the multi-line process is governed by the dual points of the line below. We also mention some other processes whose multiclass versions have the same invariant measures, and we note an extension of Burke's theorem to multiclass queues which follows from the results.

  4. Radiation-Tolerant Dual Data Bus

    NASA Technical Reports Server (NTRS)

    Kinstler, Gary A.

    2007-01-01

    An architecture, and a method of utilizing the architecture, have been proposed to enable error-free operation of a data bus that includes, and is connected to, commercial off-the-shelf (COTS) circuits and components that are inherently susceptible to singleevent upsets [SEUs (bit flips caused by impinging high-energy particles and photons)]. The architecture and method are applicable, more specifically, to data-bus circuitry based on the Institute for Electrical and Electronics Engineers (IEEE) 1394b standard for a high-speed serial bus.

  5. Dual-fuel school bus demonstration: Final report

    SciTech Connect

    Not Available

    1986-10-01

    This report describes the results of a demonstration of the capabilities of compressed natural gas (CNG) as an alternate fuel source for school bus fleets. Three New York State school districts participated in the demonstration project by converting ten buses each to dual-fuel capability. The buses could use both CNG and gasoline or CNG and diesel fuel. Each district also installed a CNG refueling station to serve their buses. School bus fleets were chosen because of their large fuel use, advantageous usage patterns and the benefits which would accrue from reduced fuel costs. The report includes both quantitative and qualitative data summarizing bus fuel enonomy; bus maintenance costs; refueling station operating and maintenance costs; regulatory problems; safety; training and community acceptance. 41 figs., 29 tabs.

  6. Average Optimal Policies in a Controlled Queueing System with Dual Admission Control

    E-print Network

    Lewis, Mark E.

    on the number of customers in the queue and the service rate of the customer currently in service. The second which may or may not occur, occurs immediately prior to the customer receiving service. That is, after each service completion the customer in the front of the queue is assessed and the service rate

  7. A dual channel high speed fiber optics multiplex data bus system

    NASA Astrophysics Data System (ADS)

    Alber, H. J.; Thomas, W. A.

    This paper provides the framework for a candidate high speed data bus. The high speed data bus is intended for use with the next generation fighter and bomber aircraft. The bus system minimizes the transport delays, optimizes the efficiency of transporting data, and minimizes the control overhead. Manchester coding plus unique start and stop identifiers are used to minimize the complexity of the encoding and decoding electronics. The token passing and centralized bus management concepts provide a deterministic system that can rapidly respond to system faults. Fiber optic point-to-point links are used to minimize the risk in connector and transceiver development, while providing for a large number of users and relatively long distances between devices.

  8. 75 FR 52054 - Bus and Bus Facilities Discretionary Program Funds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-24

    ...DEPARTMENT OF TRANSPORTATION Federal Transit Administration Bus and Bus Facilities Discretionary Program Funds AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Bus and Bus Facilities Livability program announcement of...

  9. A software bus for thread objects

    NASA Technical Reports Server (NTRS)

    Callahan, John R.; Li, Dehuai

    1995-01-01

    The authors have implemented a software bus for lightweight threads in an object-oriented programming environment that allows for rapid reconfiguration and reuse of thread objects in discrete-event simulation experiments. While previous research in object-oriented, parallel programming environments has focused on direct communication between threads, our lightweight software bus, called the MiniBus, provides a means to isolate threads from their contexts of execution by restricting communications between threads to message-passing via their local ports only. The software bus maintains a topology of connections between these ports. It routes, queues, and delivers messages according to this topology. This approach allows for rapid reconfiguration and reuse of thread objects in other systems without making changes to the specifications or source code. A layered approach that provides the needed transparency to developers is presented. Examples of using the MiniBus are given, and the value of bus architectures in building and conducting simulations of discrete-event systems is discussed.

  10. Queueing systems Renato Lo Cigno

    E-print Network

    Lo Cigno, Renato Antonio

    Chain (DT, or CT, or Semi-Markov) Queueing systems - Renato Lo Cigno - Queues definition and notation 2) (omitted if ) K: defines the total population size (omitted if ) SD: defines the serving discipline (omitted if FCFS) Queueing systems - Renato Lo Cigno - Queues definition and notation 3 #12;Kendall

  11. Session-level Queue Session-level Queue Scheduling

    E-print Network

    Chiba, Shigeru

    ( ) Web Web HTML Servlet #12;2 ( 2 ) Session-level Queue Scheduling Session-level Queue Scheduling Tomcat Servlet Session- level Queue Scheduling Servlet Session-level Queue Scheduling 2 3 4 5 6 2 Web Web [3-based Regulation 2 Web 3.2 #12;( 5 ) Vol. 0 No. 0 1983 5 3 4 3.3 Session-level Queue Scheduling Tomcat [6] ControlServlet

  12. Concurrent array-based queue

    DOEpatents

    Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2015-01-06

    According to one embodiment, a method for implementing an array-based queue in memory of a memory system that includes a controller includes configuring, in the memory, metadata of the array-based queue. The configuring comprises defining, in metadata, an array start location in the memory for the array-based queue, defining, in the metadata, an array size for the array-based queue, defining, in the metadata, a queue top for the array-based queue and defining, in the metadata, a queue bottom for the array-based queue. The method also includes the controller serving a request for an operation on the queue, the request providing the location in the memory of the metadata of the queue.

  13. Bus Training Handbook.

    ERIC Educational Resources Information Center

    Dorny, Audrea; Cole, ChiKay

    This manual presents guidelines for teaching students with disabilities necessary skills for safe and independent travel on public buses. Six guidelines for teachers include: (1) participate in bus training; (2) use wise and intelligent judgment; (3) utilize the bus checklist; (4) know and teach bus rules; (5) know bus routes; and (6) know bus

  14. A decentralized software bus based on IP multicas ting

    NASA Technical Reports Server (NTRS)

    Callahan, John R.; Montgomery, Todd

    1995-01-01

    We describe decentralized reconfigurable implementation of a conference management system based on the low-level Internet Protocol (IP) multicasting protocol. IP multicasting allows low-cost, world-wide, two-way transmission of data between large numbers of conferencing participants through the Multicasting Backbone (MBone). Each conference is structured as a software bus -- a messaging system that provides a run-time interconnection model that acts as a separate agent (i.e., the bus) for routing, queuing, and delivering messages between distributed programs. Unlike the client-server interconnection model, the software bus model provides a level of indirection that enhances the flexibility and reconfigurability of a distributed system. Current software bus implementations like POLYLITH, however, rely on a centralized bus process and point-to-point protocols (i.e., TCP/IP) to route, queue, and deliver messages. We implement a software bus called the MULTIBUS that relies on a separate process only for routing and uses a reliable IP multicasting protocol for delivery of messages. The use of multicasting means that interconnections are independent of IP machine addresses. This approach allows reconfiguration of bus participants during system execution without notifying other participants of new IP addresses. The use of IP multicasting also permits an economy of scale in the number of participants. We describe the MULITIBUS protocol elements and show how our implementation performs better than centralized bus implementations.

  15. The Bus Stops Here.

    ERIC Educational Resources Information Center

    Milshtein, Amy

    1999-01-01

    Explores some of the factors to consider before school planners decide to buy new school buses. Provides a checklist to help build and maintain a bus fleet. Concludes by addressing bus safety and advertising. (GR)

  16. Queueing Theory February 8, 2010

    E-print Network

    arrival rate #12;4 µ = Average customer service rate Recursive relationship: Wi = Wi-1 + Si-1 - Ai (9 server queueing system which consists of a server fulfilling a specific service to arriving customers who are waiting in a queue. The customer inter-arrival times are independent and identically distributed (IID

  17. Priority Queues for Computer Simulations

    NASA Technical Reports Server (NTRS)

    Steinman, Jeffrey S. (Inventor)

    1998-01-01

    The present invention is embodied in new priority queue data structures for event list management of computer simulations, and includes a new priority queue data structure and an improved event horizon applied to priority queue data structures. ne new priority queue data structure is a Qheap and is made out of linked lists for robust, fast, reliable, and stable event list management and uses a temporary unsorted list to store all items until one of the items is needed. Then the list is sorted, next, the highest priority item is removed, and then the rest of the list is inserted in the Qheap. Also, an event horizon is applied to binary tree and splay tree priority queue data structures to form the improved event horizon for event management.

  18. Hydrogen powered bus

    SciTech Connect

    2011-04-07

    Take a ride on a new type of bus, fueled by hydrogen. These hydrogen taxis are part of a Department of Energy-funded deployment of hydrogen powered vehicles and fueling infrastructure at nine federal facilities across the country to demonstrate this market-ready advanced technology. Produced and leased by Ford Motor Company , they consist of one 12- passenger bus and one nine-passenger bus. More information at: http://go.usa.gov/Tgr

  19. Hydrogen powered bus

    ScienceCinema

    None

    2013-11-22

    Take a ride on a new type of bus, fueled by hydrogen. These hydrogen taxis are part of a Department of Energy-funded deployment of hydrogen powered vehicles and fueling infrastructure at nine federal facilities across the country to demonstrate this market-ready advanced technology. Produced and leased by Ford Motor Company , they consist of one 12- passenger bus and one nine-passenger bus. More information at: http://go.usa.gov/Tgr

  20. From Waiting for the Bus to Storming the Bastille: From Sartrean Seriality to the Relationships that Form Classroom Communities

    ERIC Educational Resources Information Center

    Blenkinsop, Sean

    2012-01-01

    One of the tasks of Jean-Paul Sartre's later work was to consider how an individual could live freely within a free community. This paper examines how Sartre describes the process of group formation and the implications of this discussion for education. The paper begins with his metaphor of a bus queue in order to describe a series. Then, by means…

  1. Message passing with queues and channels

    DOEpatents

    Dozsa, Gabor J; Heidelberger, Philip; Kumar, Sameer; Ratterman, Joseph D; Steinmacher-Burrow, Burkhard

    2013-02-19

    In an embodiment, a reception thread receives a source node identifier, a type, and a data pointer from an application and, in response, creates a receive request. If the source node identifier specifies a source node, the reception thread adds the receive request to a fast-post queue. If a message received from a network does not match a receive request on a posted queue, a polling thread adds a receive request that represents the message to an unexpected queue. If the fast-post queue contains the receive request, the polling thread removes the receive request from the fast-post queue. If the receive request that was removed from the fast-post queue does not match the receive request on the unexpected queue, the polling thread adds the receive request that was removed from the fast-post queue to the posted queue. The reception thread and the polling thread execute asynchronously from each other.

  2. QUEUES IN LAW Ronen Perry*

    E-print Network

    Wintner, Shuly

    QUEUES IN LAW Ronen Perry* & Tal Z. Zarsky** INTRODUCTION the Allocator to Expand the Resource .......................39 F. Broader Social Benefits...............................................................................................57 * Professor, Faculty of Law, University of Haifa. ** Associate Professor, Faculty of Law

  3. Task allocation policies for State Dependent queues

    E-print Network

    Siew, Christine Chiu Hsia

    2011-01-01

    Consider a model of a dynamical queue with deterministic arrival and service rates, where the service rate depends on the server utilization history. This proposed queueing model occurs in many practical situations. for ...

  4. Web Page-level Queue Scheduling

    E-print Network

    Chiba, Shigeru

    -level Queue Scheduling Web Web Web 1 Web (HTML) Servlet JSP Web Page-level Queue Scheduling Servlet Java API Servlet 2 Web 3 4 5 6 7 2 Web Web Web CGI ­1­ #12;J2EE Web Web Web CPU Web I/O bound CPU I/O 1 50 1 0 1000 Scheduling Page-level Queue Scheduling Web 4 ­3­ #12;( ) 4 Page-level Queue Scheduling Java Servlet Java API

  5. MARKOV CHAINS AND QUEUEING THEORY HANNAH CONSTANTIN

    E-print Network

    May, J. Peter

    MARKOV CHAINS AND QUEUEING THEORY HANNAH CONSTANTIN Abstract. In this paper, we introduce queueing processes and find the steady- state solution to the M/M/1 queue. A brief background in Markov chains, Poisson processes, and Birth-Death processes is also given. Contents 1. Introduction to Markov Chains 1 1

  6. 7. YOSEMITE VALLEY SHUTTLE BUS AT SENTINEL BRIDGE SHUTTLE BUS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. YOSEMITE VALLEY SHUTTLE BUS AT SENTINEL BRIDGE SHUTTLE BUS AND PARKING LOT AREA. LOOKING WNW. GIS: N-37 40 36.2 / W-119 44 45.0 - Yosemite National Park Roads & Bridges, Yosemite Village, Mariposa County, CA

  7. Multipurpose satellite bus (MPS)

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Naval Postgraduate School Advanced Design Project sponsored by the Universities Space Research Association Advanced Design Program is a multipurpose satellite bus (MPS). The design was initiated from a Statement of Work (SOW) developed by the Defense Advanced Research Projects Agency (DARPA). The SOW called for a 'proposal to design a small, low-cost, lightweight, general purpose spacecraft bus capable of accommodating any of a variety of mission payloads. Typical payloads envisioned include those associated with meteorological, communication, surveillance and tracking, target location, and navigation mission areas.' The design project investigates two dissimilar missions, a meteorological payload and a communications payload, mated with a single spacecraft bus with minimal modifications. The MPS is designed for launch aboard the Pegasus Air Launched Vehicle (ALV) or the Taurus Standard Small Launch Vehicle (SSLV).

  8. Personal Computer Monitors Instrumentation Bus

    NASA Technical Reports Server (NTRS)

    Conroy, Bruce L.

    1994-01-01

    IBM-compatible personal computer used instead of logic analyzer or other special instrument to monitor IEEE-488 interface data bus that interconnects various pieces of laboratory equipment. Needed is short program for computer, commercial general-purpose interface bus circuit card, and adapter cable to link card to bus. Software available in Ada or Quick Basic language.

  9. Bus-Programmable Slave Card

    NASA Technical Reports Server (NTRS)

    Hall, William A.

    1990-01-01

    Slave microprocessors in multimicroprocessor computing system contains modified circuit cards programmed via bus connecting master processor with slave microprocessors. Enables interactive, microprocessor-based, single-loop control. Confers ability to load and run program from master/slave bus, without need for microprocessor development station. Tristate buffers latch all data and information on status. Slave central processing unit never connected directly to bus.

  10. "Ruggedized" Microcomputer Bus

    NASA Technical Reports Server (NTRS)

    Budney, T. J.; Stone, R. W. J.

    1982-01-01

    "Ruggedized" version of the STD microcomputer bus withstands rigors of space-flight. Could be used as a basis for microcomputers in other hazardous environments, including those at high and low temperatures, those in vacuum, or those subject to extreme shock and vibration.

  11. Universal Serial Bus Specification

    E-print Network

    Borgonovo, Flaminio

    Universal Serial Bus Specification Compaq Hewlett-Packard Intel Lucent Microsoft NEC Philips Technologies Inc, Microsoft Corporation, NEC Corporation, Koninklijke Philips Electronics N.V. All rights Corporation Nobuo Furuya NEC Corporation Toshimi Sakurai NEC Corporation Moto Sato NEC Corporation Katsuya

  12. SCHOOL BUS GARAGE.

    ERIC Educational Resources Information Center

    PALLIDINO, STEVE; STRIPLING, CHARLES W.

    COUNTY BOARDS, COUNTY SUPERINTENDENTS, SCHOOL PERSONNEL, AND ARCHITECTS PLANNING BUS GARAGE FACILITIES WILL FIND THIS PUBLICATION USEFUL. DECISIONS NEED TO BE MADE IN REGARD TO WHO WILL USE THE GARAGE, WHAT PURPOSE IT SHOULD SERVE, AND WHAT KIND OF SPACES ARE NEEDED. SITE SELECTION FACTORS TO BE CONSIDERED ARE LOCATION, PARKING SPACE, MANEUVERING…

  13. Augmented Thermal Bus

    NASA Technical Reports Server (NTRS)

    Schrage, Dean S. (Inventor)

    1996-01-01

    The present invention is directed to an augmented thermal bus. In the present design a plurality of thermo-electric heat pumps are used to couple a source plate to a sink plate. Each heat pump is individually controlled by a model based controller. The controller coordinates the heat pumps to maintain isothermality in the source.

  14. Bully on the Bus

    ERIC Educational Resources Information Center

    Harrison, Mary M.

    2005-01-01

    Across the U.S., more than 24 million students begin and end their school days on buses. In most cases, the driver is the only adult on board. To transport students safely, the driver must watch the road, not the riders, during most of the trip. Although bus drivers have mirrors and usually see fights, they can easily miss pushing, shoving, and…

  15. Message passing with queues and channels

    DOEpatents

    Dozsa, Gabor J; Heidelberger, Philip; Kumar, Sameer; Ratterman, Joseph D; Steinmacher-Burow, Burkhard; Wisniewski, Robert W

    2013-09-24

    In an embodiment, a send thread receives an identifier that identifies a destination node and a pointer to data. The send thread creates a first send request in response to the receipt of the identifier and the data pointer. The send thread selects a selected channel from among a plurality of channels. The selected channel comprises a selected hand-off queue and an identification of a selected message unit. Each of the channels identifies a different message unit. The selected hand-off queue is randomly accessible. If the selected hand-off queue contains an available entry, the send thread adds the first send request to the selected hand-off queue. If the selected hand-off queue does not contain an available entry, the send thread removes a second send request from the selected hand-off queue and sends the second send request to the selected message unit.

  16. Stabilization of Branching Queueing Networks

    E-print Network

    Brázdil, Tomáš

    2011-01-01

    Queueing networks are gaining attraction for the performance analysis of parallel computer systems. A Jackson network is a set of interconnected servers, where the completion of a job at server i may result in the creation of a new job for server j. We propose to extend Jackson networks by "branching" and by "control" features. Both extensions are new and substantially expand the modelling power of Jackson networks. On the other hand, the extensions raise computational questions, particularly concerning the stability of the networks, i.e, the ergodicity of the underlying Markov chain. We show for our extended model that it is decidable in polynomial time if there exists a controller that achieves stability. Moreover, if such a controller exists, one can efficiently compute a static randomized controller which stabilizes the network in a very strong sense; in particular, all moments of the queue sizes are finite.

  17. 75 FR 74134 - State of Good Repair Bus and Bus Facilities Discretionary Program Funds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-30

    ...TRANSPORTATION Federal Transit Administration State of Good Repair Bus and Bus Facilities Discretionary Program Funds AGENCY: Federal...Administration (FTA), DOT. ACTION: State of Good Repair Bus and Bus Facilities program announcement of project...

  18. Evaluation of bus emissions generated near bus stops

    NASA Astrophysics Data System (ADS)

    Yu, Qian; Li, Tiezhu

    2014-03-01

    The purpose of this research is to demonstrate a methodology for quantification of bus emissions generated near bus stops based on the real-world on-road emissions data collected by the Portable Emission Measurement System (PEMS). Data collection was carried out on an urban diesel bus throughout a bus line under normal operation condition on four work days. Stop influence zone is defined as the area in which the normal bus driving is interrupted by bus stops. The second-by-second data were screened out within the stop influence zone. And the bus running state near a stop was classified into three driving modes, deceleration, idling, and acceleration. Then emission characteristics were analyzed for each mode. Under the idling condition, the emission rates (g s-1) were not constant all the time. The NOX emission rate decreased in the first 4-6 s while the corresponding emission rates of CO2, CO, NOX, and HC increased in the last 4 s of idling. Besides, the influence of bus stop characteristics on emissions was investigated using statistical methods. Platform type, length and location of bus stops showed significant effects on the length of the stop influence zone. However, there were no significant effects on distance-based emission factors.

  19. Queueing Analysis of Wireless Network Coding Jasper Goseling

    E-print Network

    Boucherie, Richard J.

    connections to transmit, i.e., queues are saturated. Initial results on queueing models that are not basedQueueing Analysis of Wireless Network Coding Jasper Goseling j.goseling@utwente.nl Richard J as a relay for two connections. We analyze a two-dimensional continuous-time queueing model of the system

  20. Tennessee Minimum School Bus Standards.

    ERIC Educational Resources Information Center

    Tennessee State Board of Education, 2004

    2004-01-01

    The School Bus Specifications and Procedures adopted by the 2000 National Conference on School Transportation and the Federal Motor Vehicle Safety Standards (FMVSS) were used as guides by the Tennessee State Board of Education Pupil Transportation Advisory Committee in developing the revised minimum specifications for school bus chassis and school…

  1. The robotics bus: a local communications bus for robots

    NASA Astrophysics Data System (ADS)

    Gomez-Ibanez, Daniel; Stump, Ethan; Grocholsky, Benjamin P.; Kumar, Vijay; Taylor, Camillo J.

    2004-12-01

    We address the development of a local bus architecture for robot systems that facilitates modular development, and increases the reliability of systems composed of heterogeneous sensors and actuators. The communications bus is based on Control Area Network (CAN), and supports distributed processing in physically separate nodes. Modular cabling and a modular software interface facilitate assembly and modification, and all bus communication is browseable for configuration and troubleshooting. We demonstrate two implementations of this system, and discuss its performance and capabilities compared to alternate communication architectures, with specific emphasis on mobile robots.

  2. Hybrid Electric Transit Bus

    NASA Technical Reports Server (NTRS)

    Viterna, Larry A.

    1997-01-01

    A government, industry, and university cooperative is developing an advanced hybrid electric city transit bus. Goals of this effort include doubling the fuel economy compared to current buses and reducing emissions to one-tenth of current EPA standards. Unique aspects of the vehicle's power system include the use of ultra-capacitors as an energy storage system, and a planned natural gas fueled turbogenerator developed from a small jet engine. Power from both the generator and energy storage system is provided to a variable speed electric motor attached to the rear axle. At over 15000 kg gross weight, this is the largest vehicle of its kind ever built using ultra-capacitor energy storage. This paper describes the overall power system architecture, the evolution of the control strategy, and its performance over industry standard drive cycles.

  3. Preventing messaging queue deadlocks in a DMA environment

    DOEpatents

    Blocksome, Michael A; Chen, Dong; Gooding, Thomas; Heidelberger, Philip; Parker, Jeff

    2014-01-14

    Embodiments of the invention may be used to manage message queues in a parallel computing environment to prevent message queue deadlock. A direct memory access controller of a compute node may determine when a messaging queue is full. In response, the DMA may generate and interrupt. An interrupt handler may stop the DMA and swap all descriptors from the full messaging queue into a larger queue (or enlarge the original queue). The interrupt handler then restarts the DMA. Alternatively, the interrupt handler stops the DMA, allocates a memory block to hold queue data, and then moves descriptors from the full messaging queue into the allocated memory block. The interrupt handler then restarts the DMA. During a normal messaging advance cycle, a messaging manager attempts to inject the descriptors in the memory block into other messaging queues until the descriptors have all been processed.

  4. 75 FR 74134 - State of Good Repair Bus and Bus Facilities Discretionary Program Funds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-30

    ... Federal Transit Administration State of Good Repair Bus and Bus Facilities Discretionary Program Funds AGENCY: Federal Transit Administration (FTA), DOT. ACTION: State of Good Repair Bus and Bus Facilities... Transit Administration (FTA) announces the selection of projects funded with Section 5309 Bus and...

  5. 76 FR 68819 - State of Good Repair Bus and Bus Facilities Discretionary Program Funds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-07

    ... Federal Transit Administration State of Good Repair Bus and Bus Facilities Discretionary Program Funds AGENCY: Federal Transit Administration (FTA), DOT. ACTION: State of Good Repair Bus and Bus Facilities... Transit Administration (FTA) announces the selection of projects funded with Section 5309 Bus and...

  6. Design, analysis, and testing of a precision guidance, navigation, and control system for a dual-spinning Cubesat

    E-print Network

    Wise, Evan Dale

    2013-01-01

    The Microsized Microwave Atmospheric Satellite (MicroMAS) combines two traditional control approaches: a dual spinner and a three-axis gyrostat. Unlike typical dual spinners, the purpose of MicroMAS 's 2U bus and spinner ...

  7. High-Speed Ring Bus

    NASA Technical Reports Server (NTRS)

    Wysocky, Terry; Kopf, Edward, Jr.; Katanyoutananti, Sunant; Steiner, Carl; Balian, Harry

    2010-01-01

    The high-speed ring bus at the Jet Propulsion Laboratory (JPL) allows for future growth trends in spacecraft seen with future scientific missions. This innovation constitutes an enhancement of the 1393 bus as documented in the Institute of Electrical and Electronics Engineers (IEEE) 1393-1999 standard for a spaceborne fiber-optic data bus. It allows for high-bandwidth and time synchronization of all nodes on the ring. The JPL ring bus allows for interconnection of active units with autonomous operation and increased fault handling at high bandwidths. It minimizes the flight software interface with an intelligent physical layer design that has few states to manage as well as simplified testability. The design will soon be documented in the AS-1393 standard (Serial Hi-Rel Ring Network for Aerospace Applications). The framework is designed for "Class A" spacecraft operation and provides redundant data paths. It is based on "fault containment regions" and "redundant functional regions (RFR)" and has a method for allocating cables that completely supports the redundancy in spacecraft design, allowing for a complete RFR to fail. This design reduces the mass of the bus by incorporating both the Control Unit and the Data Unit in the same hardware. The standard uses ATM (asynchronous transfer mode) packets, standardized by ITU-T, ANSI, ETSI, and the ATM Forum. The IEEE-1393 standard uses the UNI form of the packet and provides no protection for the data portion of the cell. The JPL design adds optional formatting to this data portion. This design extends fault protection beyond that of the interconnect. This includes adding protection to the data portion that is contained within the Bus Interface Units (BIUs) and by adding to the signal interface between the Data Host and the JPL 1393 Ring Bus. Data transfer on the ring bus does not involve a master or initiator. Following bus protocol, any BIU may transmit data on the ring whenever it has data received from its host. There is no centralized arbitration or bus granting. The JPL design provides for autonomous synchronization of the nodes on the ring bus. An address-synchronous latency adjust buffer (LAB) has been designed that cannot get out of synchronization and needs no external input. Also, a priority-driven cable selection behavior has been programmed into each unit on the ring bus. This makes the bus able to connect itself up, according to a maximum redundancy priority system, without the need for computer intervention at startup. Switching around a failed or switched-off unit is also autonomous. The JPL bus provides a map of all the active units for the host computer to read and use for fault management. With regard to timing, this enhanced bus recognizes coordinated timing on a spacecraft as critical and addresses this with a single source of absolute and relative time, which is broadcast to all units on the bus with synchronization maintained to the tens of nanoseconds. Each BIU consists of up to five programmable triggers, which may be programmed for synchronization of events within the spacecraft of instrument. All JPL-formatted data transmitted on the ring bus are automatically time-stamped.

  8. Randomized Scheduling Algorithm for Queueing Networks

    E-print Network

    Shah, Devavrat

    2012-01-01

    There has recently been considerable interest in design of low-complexity, myopic, distributed and stable scheduling algorithms for constrained queueing network models that arise in the context of emerging communication ...

  9. FiniteSource Retrial Queues with Applications

    E-print Network

    Sztrik, János

    Queues ... Underlying Markov Chain g TwoDimensional Continuous Markov Chain (CTMC): g X(t) = (C(t), N at time t. g Graphical Representation of CTMC for K=4: Parameters: K=4 Sources : Arrival Rate : Service

  10. Computing Permutations with Double-Ended Queues, Parallel Stacks and Parallel Queues

    E-print Network

    Billey, Sara

    Computing Permutations with Double-Ended Queues, Parallel Stacks and Parallel Queues Vaughan R, rather than of a multiset of them. It is convenient to visual- ize a switchyard network as a circuit distinct) OUT. Figure I gives some familiar circuits, whose operation should be transparent. Edges

  11. The WorkQueue project - a task queue for the CMS workload management system

    NASA Astrophysics Data System (ADS)

    Ryu, S.; Wakefield, S.

    2012-12-01

    We present the development and first experience of a new component (termed WorkQueue) in the CMS workload management system. This component provides a link between a global request system (Request Manager) and agents (WMAgents) which process requests at compute and storage resources (known as sites). These requests typically consist of creation or processing of a data sample (possibly terabytes in size). Unlike the standard concept of a task queue, the WorkQueue does not contain fully resolved work units (known typically as jobs in HEP). This would require the WorkQueue to run computationally heavy algorithms that are better suited to run in the WMAgents. Instead the request specifies an algorithm that the WorkQueue uses to split the request into reasonable size chunks (known as elements). An advantage of performing lazy evaluation of an element is that expanding datasets can be accommodated by having job details resolved as late as possible. The WorkQueue architecture consists of a global WorkQueue which obtains requests from the request system, expands them and forms an element ordering based on the request priority. Each WMAgent contains a local WorkQueue which buffers work close to the agent, this overcomes temporary unavailability of the global WorkQueue and reduces latency for an agent to begin processing. Elements are pulled from the global WorkQueue to the local WorkQueue and into the WMAgent based on the estimate of the amount of work within the element and the resources available to the agent. WorkQueue is based on CouchDB, a document oriented NoSQL database. The WorkQueue uses the features of CouchDB (map/reduce views and bi-directional replication between distributed instances) to provide a scalable distributed system for managing large queues of work. The project described here represents an improvement over the old approach to workload management in CMS which involved individual operators feeding requests into agents. This new approach allows for a system where individual WMAgents are transient and can be added or removed from the system as needed.

  12. Ring Buffered Network Bus

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This report describes the research effort to demonstrate the integration of a data sharing technology, Ring Buffered Network Bus, in development by Dryden Flight Research Center, with an engine simulation application, the Java Gas Turbine Simulator, in development at the University of Toledo under a grant from the Glenn Research Center. The objective of this task was to examine the application of the RBNB technologies as a key component in the data sharing, health monitoring and system wide modeling elements of the NASA Aviation Safety Program (AVSP) [Golding, 1997]. System-wide monitoring and modeling of aircraft and air safety systems will require access to all data sources which are relative factors when monitoring or modeling the national airspace such as radar, weather, aircraft performance, engine performance, schedule and planning, airport configuration, flight operations, etc. The data sharing portion of the overall AVSP program is responsible for providing the hardware and software architecture to access and distribute data, including real-time flight operations data, among all of the AVSP elements. The integration of an engine code capable of numerically "flying" through recorded flight paths and weather data using a software tool that allows for distributed access of data to this engine code demonstrates initial steps toward building a system capable of monitoring and modeling the National Airspace.

  13. Maximally Stabilizing Task Release Control Policy for a Dynamical Queue

    E-print Network

    Savla, Ketan

    In this technical note, we introduce a model of dynamical queue, in which the service time depends on the server utilization history. The proposed queueing model is motivated by widely accepted empirical laws describing ...

  14. Wishbone bus Architecture - A Survey and Comparison

    E-print Network

    Sharma, Mohandeep; 10.5121/vlsic.2012.3210

    2012-01-01

    The performance of an on-chip interconnection architecture used for communication between IP cores depends on the efficiency of its bus architecture. Any bus architecture having advantages of faster bus clock speed, extra data transfer cycle, improved bus width and throughput is highly desirable for a low cost, reduced time-to-market and efficient System-on-Chip (SoC). This paper presents a survey of WISHBONE bus architecture and its comparison with three other on-chip bus architectures viz. Advanced Micro controller Bus Architecture (AMBA) by ARM, CoreConnect by IBM and Avalon by Altera. The WISHBONE Bus Architecture by Silicore Corporation appears to be gaining an upper edge over the other three bus architecture types because of its special performance parameters like the use of flexible arbitration scheme and additional data transfer cycle (Read-Modify-Write cycle). Moreover, its IP Cores are available free for use requiring neither any registration nor any agreement or license.

  15. Forecast analysis of optical waveguide bus performance

    NASA Technical Reports Server (NTRS)

    Ledesma, R.; Rourke, M. D.

    1979-01-01

    Elements to be considered in the design of a data bus include: architecture; data rate; modulation, encoding, detection; power distribution requirements; protocol, work structure; bus reliability, maintainability; interterminal transmission medium; cost; and others specific to application. Fiber- optic data bus considerations for a 32 port transmissive star architecture, are discussed in a tutorial format. General optical-waveguide bus concepts, are reviewed. The electrical and optical performance of a 32 port transmissive star bus, and the effects of temperature on the performance of optical-waveguide buses are examined. A bibliography of pertinent references and the bus receiver test results are included.

  16. Cycle time variability for a network under two queueing disciplines 

    E-print Network

    Vasquez Pariente, Marta Irene

    1996-01-01

    A network of three single-server queues is investigated. Performance of two queueing disciplines is compared on the basis of the mean and variance of the network cycle time. The two queueing disciplines are first-in-system first-out (FISFO...

  17. L14: Dynamic L14: Dynamic Task Queues

    E-print Network

    Hall, Mary W.

    run on larger system L14: Dynamic Task Queues 7CS6963 Sources for Today's Lecture ·"On Dynamic Load3/28/11 1 CS6963 L14: Dynamic Scheduling L14: Dynamic Task Queues 2CS6963 Administrative ·STRSM due April 25) - Final report, May 4 L14: Dynamic Task Queues 3CS6963 Design Reviews ·Goal is to see a solid

  18. Finite queues at the limit of saturation Miklos Telek

    E-print Network

    Telek, Miklós

    Finite queues at the limit of saturation Mikl´os Telek Budapest University of Technology Email: vecsei@webspn.hit.bme.hu Abstract--A wide range of real life systems are modeled by queueing of these queueing models when the load is lower or higher than the system capacity, but these numerical methods

  19. Inferring Queue Sizes in Access Networks by Active Measurement

    E-print Network

    Claypool, Mark

    of millisec- onds experience degraded Quality of Service when large access queues become saturated with otherInferring Queue Sizes in Access Networks by Active Measurement Mark Claypool, Robert Kinicki at Worcester Polytechnic Institute Worcester, MA, 01609, USA Abstract. Router queues can impact both round

  20. Controlling Internet Queue Dynamics using Recursively Identified Models

    E-print Network

    Gustafsson, Fredrik

    in amplitude until the queue saturates, which inevitably decreases performance, so a stabilizing con- trollerControlling Internet Queue Dynamics using Recursively Identified Models Frida Gunnarsson, Fredrik rate before the queue becomes full and hard drops of packets are nec- essary. State of the art

  1. NETWORK PERFORMANCE OPTIMIZATION USING A QUEUEING NETWORK MODEL

    E-print Network

    Bierlaire, Michel

    NETWORK PERFORMANCE OPTIMIZATION USING A QUEUEING NETWORK MODEL Carolina Osorio and Michel. Our an- alytic queueing network model captures this correlation and can therefore explicitly model a detailed description of congestion and analytical tractability. The model is derived from the queueing

  2. Approximate Solution of Multiclass Queueing Networks with Region Constraints

    E-print Network

    Anselmi, Jonatha

    1 Approximate Solution of Multiclass Queueing Networks with Region Constraints Jonatha Anselmi, queueing networks with "finite capacity regions" have largely proven to be effective in characterizing push. Queueing network models with finite capacity regions impose upper bounds on the number of jobs that can

  3. SIMPLE ALGORITHMS FOR ROUTING ON BUTTERFLY NETWORKS WITH BOUNDED QUEUES #

    E-print Network

    Maggs, Bruce M.

    SIMPLE ALGORITHMS FOR ROUTING ON BUTTERFLY NETWORKS WITH BOUNDED QUEUES # BRUCE M. MAGGS on butterfly networks with bounded queues. We show that for any greedy queuing protocol, a routing problem from each input to randomly chosen outputs on a butterfly with bounded­size queues in O(log N) steps

  4. Simple Algorithms for Routing on Butterfly Networks with Bounded Queues

    E-print Network

    Maggs, Bruce M.

    Simple Algorithms for Routing on Butterfly Networks with Bounded Queues (Extended Abstract) Bruce M for rout­ ing packets on butterfly networks with bounded queues. We show that for any pure queuing protocol a new algorithm for routing a random problem on a fully­ loaded butterfly with bounded­size queues in O

  5. Some Questions to Ask about Your School Bus Program.

    ERIC Educational Resources Information Center

    Balousek, Marvin

    1980-01-01

    Questions based on observations of a Chicago (Illinois) school bus program deal with driver capability, procedures for bus evacuation in an emergency, bus comfort for passengers, safety, fuel efficiency, and creative use of students' bus time. (MLF)

  6. 49 CFR 605.19 - Approval of school bus operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Approval of school bus operations. 605.19 Section 605.19 Transportation...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.19 Approval of school bus...

  7. Preliminary Flight Results of the Microelectronics and Photonics Test Bed: NASA DR1773 Fiber Optic Data Bus Experiment

    NASA Technical Reports Server (NTRS)

    Jackson, George L.; LaBel, Kenneth A.; Marshall, Cheryl; Barth, Janet; Seidleck, Christina; Marshall, Paul

    1998-01-01

    NASA Goddard Spare Flight Center's (GSFC) Dual Rate 1773 (DR1773) Experiment on the Microelectronic and Photonic Test Bed (MPTB) has provided valuable information on the performance of the AS 1773 fiber optic data bus in the space radiation environment. Correlation of preliminary experiment data to ground based radiation test results show the AS 1773 bus is employable in future spacecraft applications requiring radiation tolerant communication links.

  8. How to Computerize School Bus Scheduling.

    ERIC Educational Resources Information Center

    Creighton, Roger L.

    1986-01-01

    School systems will soon be using microcomputers to design their school bus routes and aid in the management of transportation programs. Offers guidelines to bring microcomputer bus management to school systems. (MLF)

  9. Efficiency and robustness of different bus network designs

    NASA Astrophysics Data System (ADS)

    Pang, John Zhen Fu; Bin Othman, Nasri; Ng, Keng Meng; Monterola, Christopher

    2015-07-01

    We compare the efficiencies and robustness of four transport networks that can be possibly formed as a result of deliberate city planning. The networks are constructed based on their spatial resemblance to the cities of Manhattan (lattice), Sudan (random), Beijing (single-blob) and Greater Cairo (dual-blob). For a given type, a genetic algorithm is employed to obtain an optimized set of the bus routes. We then simulate how commuter travels using Yen's algorithms for k shortest paths on an adjacency matrix. The cost of traveling such as walking between stations is captured by varying the weighted sums of matrices. We also consider the number of transfers a posteriori by looking at the computed shortest paths. With consideration to distances via radius of gyration, redundancies of travel and number of bus transfers, our simulations indicate that random and dual-blob are more efficient than single-blob and lattice networks. Moreover, dual-blob type is least robust when node removals are targeted but is most resilient when node failures are random. The work hopes to guide and provide technical perspectives on how geospatial distribution of a city limits the optimality of transport designs.

  10. An improved bus signal priority system for networks with nearside bus stops 

    E-print Network

    Kim, Wonho

    2005-02-17

    .............................................27 3.1 Study Site Selection and Description....................................................27 3.2 Data Collection.....................................................................................30 3.2.1 Bus Dwell Time Data... ..............................................................................................................Page Table 2-1 Typical bus passenger boarding and alighting service times for selected bus types and door configurations (41)......................................22 Table 3-1 Scheduled bus headway...

  11. The NASA bus communications listening device software

    NASA Technical Reports Server (NTRS)

    Allen, M. A.

    1979-01-01

    The development of the bus listener is presented. Special software was developed to control the 'bus interface units' (BIU) connecting each of these devices to a communications cable to form the bus communication network. The code used in the BTU is described.

  12. Queue length analysis for multicast: Limits of performance and achievable queue length with random linear coding

    E-print Network

    Cogill, Randy

    In this work we analyze the average queue backlog at a source node serving a single multicast flow consisting of M destination nodes. In the model we consider, the channel between the source node and each receiver is an ...

  13. Pybus -- A Python Software Bus

    SciTech Connect

    Lavrijsen, Wim T.L.P.

    2004-10-14

    A software bus, just like its hardware equivalent, allows for the discovery, installation, configuration, loading, unloading, and run-time replacement of software components, as well as channeling of inter-component communication. Python, a popular open-source programming language, encourages a modular design on software written in it, but it offers little or no component functionality. However, the language and its interpreter provide sufficient hooks to implement a thin, integral layer of component support. This functionality can be presented to the developer in the form of a module, making it very easy to use. This paper describes a Pythonmodule, PyBus, with which the concept of a ''software bus'' can be realized in Python. It demonstrates, within the context of the ATLAS software framework Athena, how PyBus can be used for the installation and (run-time) configuration of software, not necessarily Python modules, from a Python application in a way that is transparent to the end-user.

  14. HERMES travels by CAN bus

    NASA Astrophysics Data System (ADS)

    Waller, Lewis G.; Shortridge, Keith; Farrell, Tony J.; Vuong, Minh; Muller, Rolf; Sheinis, Andrew I.

    2014-07-01

    The new HERMES spectrograph represents the first foray by AAO into the use of commercial off-the-shelf industrial field bus technology for instrument control, and we regard the final system, with its relatively simple wiring requirements, as a great success. However, both software and hardware teams had to work together to solve a number of problems integrating the chosen CANopen/CAN bus system into our normal observing systems. A Linux system running in an industrial PC chassis ran the HERMES control software, using a PCI CAN bus interface connected to a number of distributed CANopen/CAN bus I/O devices and servo amplifiers. In the main, the servo amplifiers performed impressively, although some experimentation with homing algorithms was required, and we hit a significant hurdle when we discovered that we needed to disable some of the encoders used during observations; we learned a lot about how servo amplifiers respond when their encoders are turned off, and about how encoders react to losing power. The software was based around a commercial CANopen library from Copley Controls. Early worries about how this heavily multithreaded library would work with our standard data acquisition system led to the development of a very low-level CANopen software simulator to verify the design. This also enabled the software group to develop and test almost all the control software well in advance of the construction of the hardware. In the end, the instrument went from initial installation at the telescope to successful commissioning remarkably smoothly.

  15. University of Minnesota Crookston Registration Queue

    E-print Network

    Minnesota, University of

    the new registration system. Tools for how to navigate through the new system are forthcoming. PleaseUniversity of Minnesota Crookston Registration Queue Summer Session and Fall Semester 2015 Students non-degree students April 24 ONLINE COURSE REGISTRATION PRIORITY Online degree-seeking students who

  16. Electrical system architecture having high voltage bus

    DOEpatents

    Hoff, Brian Douglas (East Peoria, IL); Akasam, Sivaprasad (Peoria, IL)

    2011-03-22

    An electrical system architecture is disclosed. The architecture has a power source configured to generate a first power, and a first bus configured to receive the first power from the power source. The architecture also has a converter configured to receive the first power from the first bus and convert the first power to a second power, wherein a voltage of the second power is greater than a voltage of the first power, and a second bus configured to receive the second power from the converter. The architecture further has a power storage device configured to receive the second power from the second bus and deliver the second power to the second bus, a propulsion motor configured to receive the second power from the second bus, and an accessory motor configured to receive the second power from the second bus.

  17. PinBus Interface Design

    SciTech Connect

    Hammerstrom, Donald J.; Adgerson, Jewel D.; Sastry, Chellury; Pratt, Richard M.; Pratt, Robert G.

    2009-12-30

    On behalf of the U.S. Department of Energy, PNNL has explored and expanded upon a simple control interface that might have merit for the inexpensive communication of smart grid operational objectives (demand response, for example) to small electric end-use devices and appliances. The approach relies on bi-directional communication via the electrical voltage states of from one to eight shared interconnection pins. The name PinBus has been suggested and adopted for the proposed interface protocol. The protocol is defined through the presentation of state diagrams and the pins’ functional definitions. Both simulations and laboratory demonstrations are being conducted to demonstrate the elegance and power of the suggested approach. PinBus supports a very high degree of interoperability across its interfaces, allowing innumerable pairings of devices and communication protocols and supporting the practice of practically any smart grid use case.

  18. 76 FR 68819 - State of Good Repair Bus and Bus Facilities Discretionary Program Funds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-07

    ...program information on the Bus and Bus Facilities program contact Samuel Snead, Office of Program Management, at (202) 366-1089, email: Samuel.Snead@dot.gov, or Kimberly Sledge, Office of Program Management, at (202) 366-2053, email:...

  19. Theoretical description of metabolism using queueing theory.

    PubMed

    Evstigneev, Vladyslav P; Holyavka, Marina G; Khrapatiy, Sergii V; Evstigneev, Maxim P

    2014-09-01

    A theoretical description of the process of metabolism has been developed on the basis of the Pachinko model (see Nicholson and Wilson in Nat Rev Drug Discov 2:668-676, 2003) and the queueing theory. The suggested approach relies on the probabilistic nature of the metabolic events and the Poisson distribution of the incoming flow of substrate molecules. The main focus of the work is an output flow of metabolites or the effectiveness of metabolism process. Two simplest models have been analyzed: short- and long-living complexes of the source molecules with a metabolizing point (Hole) without queuing. It has been concluded that the approach based on queueing theory enables a very broad range of metabolic events to be described theoretically from a single probabilistic point of view. PMID:25142745

  20. The Modular Building Block data bus

    SciTech Connect

    Not Available

    1987-05-01

    This document presents a generic description of the Modular Building Block data bus which also includes the bus control processor. The data bus uses coaxial cable as the physical communication medium and employs frequency division multiplexing to accommodate audio, digital, and video signals from a wide variety of computers, radios, telephones, PBXs, cryptos, and other mission equipment. Other documents generated as part of the design definition for specific applications will provide details on subjects such as power levels, power consumption, and frequency allocations.

  1. The Average Velocity in a Queue

    ERIC Educational Resources Information Center

    Frette, Vidar

    2009-01-01

    A number of cars drive along a narrow road that does not allow overtaking. Each driver has a certain maximum speed at which he or she will drive if alone on the road. As a result of slower cars ahead, many cars are forced to drive at speeds lower than their maximum ones. The average velocity in the queue offers a non-trivial example of a mean…

  2. Cost performance satellite design using queueing theory

    NASA Technical Reports Server (NTRS)

    Hein, G. F.

    1975-01-01

    The Poisson arrival model was used to determine the effects of limiting the number of channels for a disaster warning satellite. State probabilities and delay probabilities were estimated for several values of the number of channels (C) for arrival and service rates obtained from disaster warnings issued by the National Weather Service. The results predicted by the queueing model were compared with the results of a digital computer simulation.

  3. 49 CFR 374.317 - Identification-bus and driver.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false Identification-bus and driver. 374.317 Section 374.317 Transportation...Service § 374.317 Identification—bus and driver. Each bus and driver providing service shall be identified in a...

  4. 49 CFR 374.317 - Identification-bus and driver.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false Identification-bus and driver. 374.317 Section 374.317 Transportation...Service § 374.317 Identification—bus and driver. Each bus and driver providing service shall be identified in a...

  5. 49 CFR 374.317 - Identification-bus and driver.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Identification-bus and driver. 374.317 Section 374.317 Transportation...Service § 374.317 Identification—bus and driver. Each bus and driver providing service shall be identified in a...

  6. 49 CFR 374.317 - Identification-bus and driver.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Identification-bus and driver. 374.317 Section 374.317 Transportation...Service § 374.317 Identification—bus and driver. Each bus and driver providing service shall be identified in a...

  7. Road safety issues for bus transport management.

    PubMed

    Cafiso, Salvatore; Di Graziano, Alessandro; Pappalardo, Giuseppina

    2013-11-01

    Because of the low percentage of crashes involving buses and the assumption that public transport improves road safety by reducing vehicular traffic, public interest in bus safety is not as great as that in the safety of other types of vehicles. It is possible that less attention is paid to the significance of crashes involving buses because the safety level of bus systems is considered to be adequate. The purpose of this study was to evaluate the knowledge and perceptions of bus managers with respect to safety issues and the potential effectiveness of various technologies in achieving higher safety standards. Bus managers were asked to give their opinions on safety issues related to drivers (training, skills, performance evaluation and behaviour), vehicles (maintenance and advanced devices) and roads (road and traffic safety issues) in response to a research survey. Kendall's algorithm was used to evaluate the level of concordance. The results showed that the majority of the proposed items were considered to have great potential for improving bus safety. The data indicated that in the experience of the participants, passenger unloading and pedestrians crossing near bus stops are the most dangerous actions with respect to vulnerable users. The final results of the investigation showed that start inhibition, automatic door opening, and the materials and internal architecture of buses were considered the items most strongly related to bus passenger safety. Brake assistance and vehicle monitoring systems were also considered to be very effective. With the exception of driver assistance systems for passenger and pedestrian safety, the perceptions of the importance of other driver assistance systems for vehicle monitoring and bus safety were not unanimous among the bus company managers who participated in this survey. The study results showed that the introduction of new technologies is perceived as an important factor in improving bus safety, but a better understanding of their actual effectiveness and related risk factor avoidance must be developed to permit their useful implementation in bus fleets. PMID:23850401

  8. Modeling Energy Consumption of Lock-Free Queue Implementations

    E-print Network

    Tsigas, Philippas

    Modeling Energy Consumption of Lock-Free Queue Implementations Aras Atalar, Anders Gidenstam, Paul Renaud-Goud and Philippas Tsigas Chalmers University of Technology, 412 58 G¨oteborg; Email: name of modeling the energy behavior of lock-free concurrent queue data structures. Our main contribution is a way

  9. Work Queue + Python: A Framework For Scalable Scientific Ensemble Applications

    E-print Network

    Thain, Douglas

    Work Queue + Python: A Framework For Scalable Scientific Ensemble Applications Peter Bui, Dinesh Work Queue, a flexible master/- worker framework for building large scale scientific ensemble ap- plications that span many machines including clusters, grids, and clouds. In this paper, we describe Work

  10. A queueing network model of Oracle Parallel Uli Harder

    E-print Network

    Imperial College, London

    A queueing network model of Oracle Parallel Server Uli Harder and Peter Harrison September 18 and parallel server versions. A modified queueing network is used which is extended to include traditional saturation point for the number of concurrent transactions executing, as is observed in many systems

  11. A POPULATION-MIX DRIVEN APPROXIMATION FOR QUEUEING

    E-print Network

    Anselmi, Jonatha

    regions and shared constraints. The approach is based on Norton's theorem for queueing networks, in which each region is replaced by a Flow Equivalent Service Center (FESC). We propose a population-mix driven queueing network, nite capacity region, ow-equivalent server 1. INTRODUCTION Among existing modeling

  12. SIMPLE ALGORITHMS FOR ROUTING ON BUTTERFLY NETWORKS WITH BOUNDED QUEUES

    E-print Network

    Maggs, Bruce M.

    SIMPLE ALGORITHMS FOR ROUTING ON BUTTERFLY NETWORKS WITH BOUNDED QUEUES BRUCE M. MAGGS AND RAMESH K­1003 Abstract. This paper examines several simple algorithms for routing packets on butterfly networks to randomly chosen outputs on a butterfly with bounded-size queues in O(log N) steps, with high probability

  13. Interprocessor bus switching system for simultaneous communication in plural bus parallel processing system

    DOEpatents

    Atac, R.; Fischler, M.S.; Husby, D.E.

    1991-01-15

    A bus switching apparatus and method for multiple processor computer systems comprises a plurality of bus switches interconnected by branch buses. Each processor or other module of the system is connected to a spigot of a bus switch. Each bus switch also serves as part of a backplane of a modular crate hardware package. A processor initiates communication with another processor by identifying that other processor. The bus switch to which the initiating processor is connected identifies and secures, if possible, a path to that other processor, either directly or via one or more other bus switches which operate similarly. If a particular desired path through a given bus switch is not available to be used, an alternate path is considered, identified and secured. 11 figures.

  14. Interprocessor bus switching system for simultaneous communication in plural bus parallel processing system

    DOEpatents

    Atac, Robert (Aurora, IL); Fischler, Mark S. (Warrenville, IL); Husby, Donald E. (DeKalb, IL)

    1991-01-01

    A bus switching apparatus and method for multiple processor computer systems comprises a plurality of bus switches interconnected by branch buses. Each processor or other module of the system is connected to a spigot of a bus switch. Each bus switch also serves as part of a backplane of a modular crate hardware package. A processor initiates communication with another processor by identifying that other processor. The bus switch to which the initiating processor is connected identifies and secures, if possible, a path to that other processor, either directly or via one or more other bus switches which operate similarly. If a particular desired path through a given bus switch is not available to be used, an alternate path is considered, identified and secured.

  15. Architectural Power Optimization by Bus Splitting

    E-print Network

    Pedram, Massoud

    size Lower power consumption Lower noise problems #12;5 Probabilistic Power Model of Driver o in oe Vp1 Architectural Power Optimization by Bus Splitting Cheng-Ta Hsieh Verplex System Massoud Pedram-to-Point Connection Power Model and Examples Algorithm Summary #12;2 Prior Work Low Voltage Swing [Nakagome, `93] Bus

  16. Priority Queuing On A Parallel Data Bus

    NASA Technical Reports Server (NTRS)

    Wallis, D. E.

    1985-01-01

    Queuing strategy for communications along shared data bus minimizes number of data lines while always assuring user of highest priority given access to bus. New system handles up to 32 user demands on 17 data lines that previously serviced only 17 demands.

  17. California's Bus Driver's Training Course. Instructor's Manual.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento.

    This instructor's manual was designed to help graduates of the California Bus Driver Instructor Course provide effective instruction to school bus driver trainees. It contains enough material for 20-30 hours of classroom training. The information is organized in 12 instructional units that cover the following topics: introduction to the course;…

  18. Hidden Savings in your Bus Budget

    ERIC Educational Resources Information Center

    Newby, Ruth

    2005-01-01

    School transportation industry statistics show the annual average costs for operating and maintaining a single school bus range from $34,000 to $38,000. Operating a school bus fleet at high efficiency has a real impact on the dollars saved for a school district and the reliability of transportation service to students. In this article, the author…

  19. Connecting Separate Computers to a Common Bus

    NASA Technical Reports Server (NTRS)

    Agrawan, A. K.; Mullen, P. G.; Vadakan, V. V.

    1984-01-01

    Network bus adapter (NBA) handles protocols for computer-tocomputer communications. NBA does all protocol handling and communications with bus for its host computer, that processor of different speeds sends data to each other continuously at maximum speed. Any host can communicate with any other, or several or with all.

  20. School Bus Maintenance. Bulletin, 1948, No. 2

    ERIC Educational Resources Information Center

    Featherston, E. Glenn

    1948-01-01

    This bulletin is one in the series on pupil transportation issued by the Office of Education. Its purpose is to furnish information and guidance for local school administrators and others who are concerned with school bus maintenance. Programs of school bus maintenance vary among the 48 States. Presumably all contract vehicles are maintained by…

  1. Worstcase and Nash Routing Policies in Parallel Queues with Uncertain Service Allocations

    E-print Network

    ­sum game analysis yields that the optimal strategy for the router is `join the shortest queue', while. Games/group decisions, stochastic games: controlled queueing systems. Introduction We consider two. The queues are attended by several servers which are free to move between the queues. Fixed servers which

  2. A surrogate model for traffic optimization of congested networks: an analytic queueing network approach

    E-print Network

    Bierlaire, Michel

    A surrogate model for traffic optimization of congested networks: an analytic queueing network queueing network model that resorts to finite capacity queueing theory to account for congested conditions. Existing analytic queueing models for urban networks are formulated for a single intersection, and thus do

  3. A Queueing Model for Evaluating the Transfer Latency of Peer to Peer Systems

    E-print Network

    Sikdar, Biplab

    1 A Queueing Model for Evaluating the Transfer Latency of Peer to Peer Systems Krishna Kumar Ramachandran and Biplab Sikdar Member, IEEE Abstract--This paper presents a queueing model to evaluate a queueing model that models the nodes or peers in such systems as M/G/1/K processor sharing queues

  4. NASA TM 109025 (Revision 1) -1 A Comparison of Queueing, Cluster and

    E-print Network

    Nelson, Michael L.

    NASA TM 109025 (Revision 1) - 1 A Comparison of Queueing, Cluster and Distributed Computing Systems management and queueing systems: COmputing in DIstributed Networked Environments (CODINE), Condor, CONNECT:Queue (formerly NQS/Exec), Distributed Job Manager (DJM), Distributed Queueing System (DQS), Load Balancer, Load

  5. On the Saturation Rule for the Stability of Queues Francois Baccelli

    E-print Network

    Foss, Serguei

    On the Saturation Rule for the Stability of Queues Franc¸ois Baccelli and Serguei Foss February 1 region is given by the following saturation rule: `saturate' the queues which are fed by the external queueing systems can be obtained as follows: `saturate' the queues which are fed by the external arrival

  6. Weighted scheduling based on queue length and delay for AOPS

    NASA Astrophysics Data System (ADS)

    Chen, Qianbin; Pang, Junyu; Liu, Huanlin

    2007-11-01

    Packet scheduling plays an important role in the asynchronous optical switched networks for node performance. A weighted scheduling algorithm based on the queue length associated with waiting delay was proposed to solve the packet starvation of queue length weighted scheduling for the length variable OPS. The contention is resolved either in wavelength domain by limited range wavelength converters and in time domain by fiber delay lines. The work has contributed with a very powerful scheduling mechanism which reduces resource contention at the asynchronous OPS core nodes and guarantees a reasonable packet delay thanks to its weighted scheduling algorithm based on queue length and waiting delay for variable length OPS network. The scheduler calculates every input ports with N×K virtual output queue (VOQ) weight and schedules the maximal weight queue packets to available output channel. The analysis and simulation results show that the proposed scheduling has high throughput and low packet loss ratio.

  7. Session-aware Queue Scheduling Web Session-aware Queue Scheduling SQS

    E-print Network

    Chiba, Shigeru

    including sessions. The result shows that SQS improves server throughput for session. 1 Web Web Web Servlet (currently MRI). , Vol.23, No.2 (2006), pp.1­12. [ ] 2005 5 20 . Web Web 1 #12;2 HTML Servlet [16] 1 Session queue monitor session scheduler 3 1 3 #12;6 3. 3 SQS Tomcat [1] ControlServlet ControlServlet Servlet

  8. Analog bus driver and multiplexer

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata (Inventor); Hancock, Bruce (Inventor); Cunningham, Thomas J. (Inventor)

    2012-01-01

    For a source-follower signal chain, the ohmic drop in the selection switch causes unacceptable voltage offset, non-linearity, and reduced small signal gain. For an op amp signal chain, the required bias current and the output noise rises rapidly with increasing the array format due to a rapid increase in the effective capacitance caused by the Miller effect boosting up the contribution of the bus capacitance. A new switched source-follower signal chain circuit overcomes limitations of existing op-amp based or source follower based circuits used in column multiplexers and data readout. This will improve performance of CMOS imagers, and focal plane read-out integrated circuits for detectors of infrared or ultraviolet light.

  9. 49 CFR 605.19 - Approval of school bus operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Approval of school bus operations. 605.19 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.19 Approval of school bus operations. (a) The Administrator will consider the comments filed by private school...

  10. Ultralight Stainless Steel Urban Bus Concept

    SciTech Connect

    J. Bruce Emmons; Leonard J. Blessing

    2001-05-14

    While stainless steel buses are certainly not new, this study reveals opportunities for substantial improvements in structural performance.The objective of this project was to investigate the mass saving potential of ultra-high strength stainless steel as applied to the structure of a full size urban transit bus.The resulting design for a low floor,hybrid bus has an empty weight less than half that of a conventional transit bus.The reduced curb weight allows for a greater payload,without exceeding legal axle limits. A combination of finite element modeling and dynamic testing of scale models was used to predict structural performance.

  11. Dynamical analysis of the exclusive queueing process

    NASA Astrophysics Data System (ADS)

    Arita, Chikashi; Schadschneider, Andreas

    2011-05-01

    Recently, the stationary state of a parallel-update totally asymmetric simple exclusion process with varying system length, which can be regarded as a queueing process with excluded-volume effect (exclusive queueing process), was obtained [C Arita and D Yanagisawa, J. Stat. Phys.JSTPBS0022-471510.1007/s10955-010-0075-9 141, 829 (2010)]. In this paper, we analyze the dynamical properties of the number of particles and the position of the last particle (the system length) , using an analytical method (generating function technique) as well as a phenomenological description based on domain-wall dynamics and Monte Carlo simulations. The system exhibits two phases corresponding to linear convergence or divergence of and . These phases can both further be subdivided into high-density and maximal-current subphases. The predictions of the domain-wall theory are found to be in very good agreement quantitively with results from Monte Carlo simulations in the convergent phase. On the other hand, in the divergent phase, only the prediction for agrees with simulations.

  12. Critical behavior of the exclusive queueing process

    NASA Astrophysics Data System (ADS)

    Arita, Chikashi; Schadschneider, Andreas

    2013-11-01

    The exclusive queueing process (EQP) is a generalization of the classical M/M/1 queue. It is equivalent to a totally asymmetric exclusion process (TASEP) of varying length. Here we consider two discrete-time versions of the EQP with parallel and backward-sequential update rules. The phase diagram (with respect to the arrival probability ? and the service probability ?) is divided into two phases corresponding to divergence and convergence of the system length. We investigate the behavior on the critical line separating these phases. For both update rules, we find diffusive behavior for small service probability (\\beta < \\beta_c) . However, for \\beta>\\beta_c it becomes sub-diffusive and nonuniversal: the critical exponents characterizing the divergence of the system length and the number of customers are found to depend on the update rule. For the backward-update case, they also depend on the hopping parameter p, and remain finite when p is large, indicating a first-order transition.

  13. Updatable Queue Protocol Based On TCP For Virtual Reality Environment

    E-print Network

    Al-Howaide, Ala'a Z; Salhieh, Ayad M

    2011-01-01

    The variance in number and types of tasks required to be implemented within Distributed Virtual Environments (DVE) highlights the needs for communication protocols can achieve consistency. In addition, these applications have to handle an increasing number of participants and deal with the difficult problem of scalability. Moreover, the real-time requirements of these applications make the scalability problem more difficult to solve. In this paper, we have implemented Updatable Queue Abstraction protocol (UQA) on TCP (TCP-UQA) and compared it with original TCP, UDP, and Updatable Queue Abstraction based on UDP (UDP-UQA) protocols. Results showed that TCP-UQA was the best in queue management.

  14. Analysis and simulation of a city bus route

    NASA Astrophysics Data System (ADS)

    Kar, Leow Soo

    2014-12-01

    Public transport in crowded cities, in particular bus services play an essential role in the mobility of its citizenry. However, an efficient, reliable and safe bus system is still a distant dream of many cities. This paper uses a simulation approach to provide some insight into the factors that contribute to the service quality of a bus system. SAS Simulation Studio is used to model a city bus route. The simulation model consists of a bus depot, bus stops, terminal station and a bus route. Parameters used in the simulation include the number of buses serving the route, maximum bus capacity, inter departure time of buses, travel time between stops, number of passengers boarding and alighting. The simulation is applied to a real bus route in Kuala Lumpur city center and a sensitivity analysis is performed to evaluate how the different variables affect the service quality of the bus system.

  15. Increasing available FIFO space to prevent messaging queue deadlocks in a DMA environment

    DOEpatents

    Blocksome, Michael A. (Rochester, MN); Chen, Dong (Croton On Hudson, NY); Gooding, Thomas (Rochester, MN); Heidelberger, Philip (Cortlandt Manor, NY); Parker, Jeff (Rochester, MN)

    2012-02-07

    Embodiments of the invention may be used to manage message queues in a parallel computing environment to prevent message queue deadlock. A direct memory access controller of a compute node may determine when a messaging queue is full. In response, the DMA may generate an interrupt. An interrupt handler may stop the DMA and swap all descriptors from the full messaging queue into a larger queue (or enlarge the original queue). The interrupt handler then restarts the DMA. Alternatively, the interrupt handler stops the DMA, allocates a memory block to hold queue data, and then moves descriptors from the full messaging queue into the allocated memory block. The interrupt handler then restarts the DMA. During a normal messaging advance cycle, a messaging manager attempts to inject the descriptors in the memory block into other messaging queues until the descriptors have all been processed.

  16. 16 Load Data Cleansing and Bus Load

    E-print Network

    Wang, Ke

    375 16 Load Data Cleansing and Bus Load Coincidence Factors* Wenyuan Li, Ke Wang, and Wijarn .................................................................................................. 375 16.2 Load Curve Data Cleansing..................................................................................377 16.2.2 Method for Cleansing Outliers .........................................................378

  17. Simulation Model of the Bus Stop

    NASA Astrophysics Data System (ADS)

    B?k, Rados?aw

    2010-03-01

    On the basis of the research conducted at the bus stops in Krakow and Warsaw, the movement processes, related with functioning of a bus stop have been identified. As a result, the simulation model imitating its functioning has been formulated and verified. The stop has been analyzed as a system, in which the input flow comprises of municipal bus transport, whereas the service time corresponds the dwell time. The formulas for time losses incurred due to queuing to reach the boarding and alighting zones have been derived, constituting a basis for operative capacity estimation of a bus stop and specifying the selection determinants for the number of boarding and alighting zones in regards to traffic intensity as well as boarding and alighting time.

  18. Performance and reliability of Multistage Bus Network 

    E-print Network

    Askar, Tahsin

    1993-01-01

    the economic design and fast broadcast advantages of the bus based systems. In this thesis performance analysis of MBN in loosely coupled system is presented. The network operates in a synchronous, decentralized packet-switched mode and has infinite buffers...

  19. Systems evaluation of thermal bus concepts

    NASA Technical Reports Server (NTRS)

    Stalmach, D. D.

    1982-01-01

    Thermal bus concepts, to provide a centralized thermal utility for large, multihundred kilowatt space platforms, were studied and the results are summarized. Concepts were generated, defined, and screened for inclusion in system level thermal bus trades. Parametric trade studies were conducted in order to define the operational envelope, performance, and physical characteristics of each. Two concepts were selected as offering the most promise for thermal bus development. All of four concepts involved two phase flow in order to meet the required isothermal nature of the thermal bus. Two of the concepts employ a mechanical means to circulate the working fluid, a liquid pump in one case and a vapor compressor in another. Another concept utilizes direct osmosis as the driving force of the thermal bus. The fourth concept was a high capacity monogroove heat pipe. After preliminary sizing and screening, three of these concepts were selected to carry into the trade studies. The monogroove heat pipe concept was deemed unsuitable for further consideration because of its heat transport limitations. One additional concept utilizing capillary forces to drive the working fluid was added. Parametric system level trade studies were performed. Sizing and weight calculations were performed for thermal bus sizes ranging from 5 to 350 kW and operating temperatures in the range of 4 to 120 C. System level considerations such as heat rejection and electrical power penalties and interface temperature losses were included in the weight calculations.

  20. Scheduling in switched queueing networks with heavy-tailed trac

    E-print Network

    Markakis, Mihalis G

    2013-01-01

    We study scheduling problems arising in switched queueing networks, a class of stochastic systems that are often used to model data communication networks, such as uplinks and downlinks of cellular networks, networks of ...

  1. Opportunistic Channel Scheduling for Ad Hoc Networks with Queue Stability

    NASA Astrophysics Data System (ADS)

    Dong, Lei; Wang, Yongchao

    2015-03-01

    In this paper, a distributed opportunistic channel access strategy in ad hoc network is proposed. We consider the multiple sources contend for the transmission opportunity, the winner source decides to transmit or restart contention based on the current channel condition. Owing to real data assumption at all links, the decision still needs to consider the stability of the queues. We formulate the channel opportunistic scheduling as a constrained optimization problem which maximizes the system average throughput with the constraints that the queues of all links are stable. The proposed optimization model is solved by Lyapunov stability in queueing theory. The successive channel access problem is decoupled into single optimal stopping problem at every frame and solved with Lyapunov algorithm. The threshold for every frame is different, and it is derived based on the instantaneous queue information. Finally, computer simulations are conducted to demonstrate the validity of the proposed strategy.

  2. MergeArray and scalable, relaxed, concurrent, mergeable priority queues

    E-print Network

    Coulombe, Michael Joseph

    2015-01-01

    The priority queue is a well-studied data structure which has prospered in the ever-growing field of distributed computing. However, in the asynchronous shared-memory model, one operation was left behind: merge. I present ...

  3. Queueing Behavior over a Gilbert-Elliott Packet Erasure Channel 

    E-print Network

    Cai, Yi

    2012-02-14

    . Exploiting this mathematical structure, the probability of the queue exceeding a certain threshold can be obtained. Most previous contributions in this area treat code-rate selection, channel erasure probability and network congestion separately...

  4. An N Server Cutoff Multi-Priority Queue

    E-print Network

    Schaack, Christian

    Consider a multi-priority, nonpreemptive, N-server Poisson arrival queueing system. Service times are negative exponential. In order to save available servers for higher priority customers, arriving customers of each lower ...

  5. Queueing systems subject to random server failures: an approximation 

    E-print Network

    Matis, Timothy

    1998-01-01

    are arbitrary), and yet maintains computational simplicity and efficiency. This method will be obtained through the implementation of a stationary delayed renewal process and simple modifications of common approximation formulas for a G/G/m queue. Through...

  6. THE TRANSIENT BMAP / G /1 BMAP / G /1 QUEUE

    E-print Network

    Whitt, Ward

    THE TRANSIENT BMAP / G /1 BMAP / G /1 QUEUE David M. Lucantoni 11 Gagan L. Choudhury 22 Ward Whitt Laboratories, Room 2C­178, Murray Hill, NJ 07974­0636, #12; 1. Introduction In this paper we consider

  7. Optimal Routing in General Finite Multi-Server Queueing Networks

    PubMed Central

    van Woensel, Tom; Cruz, Frederico R. B.

    2014-01-01

    The design of general finite multi-server queueing networks is a challenging problem that arises in many real-life situations, including computer networks, manufacturing systems, and telecommunication networks. In this paper, we examine the optimal routing problem in arbitrary configured acyclic queueing networks. The performance of the finite queueing network is evaluated with a known approximate performance evaluation method and the optimization is done by means of a heuristics based on the Powell algorithm. The proposed methodology is then applied to determine the optimal routing probability vector that maximizes the throughput of the queueing network. We show numerical results for some networks to quantify the quality of the routing vector approximations obtained. PMID:25010660

  8. The SprayList : a scalable relaxed priority queue

    E-print Network

    Li, Jerry Zheng

    2015-01-01

    High-performance concurrent priority queues are essential for applications such as task scheduling and discrete event simulation. Unfortunately, even the best performing implementations do not scale past a number of threads ...

  9. Queueing Systems manuscript No. (will be inserted by the editor)

    E-print Network

    Whitt, Ward

    the thresholds), which is a special case of the queue-and-idleness ratio (QIR) controls suggested in [11 on both the class and the pool, FQR can perform badly in cyclic networks, creating severe congestion even

  10. Queueing analysis for multicast packet switching

    NASA Astrophysics Data System (ADS)

    Hui, Joseph Y.; Renner, Thomas

    1994-02-01

    The development of broadband transmission and ATM switching technologies opens up an opportunity for providing high bit-rate multipoint and multimedia services such as video conferencing. Also, wireless communication has the inherent advantage of multicast transmission and may be used for multipoint information services. We consider multicast packet switching for which an input may send the same packet to many outputs within an ATM time slot. A host of multicast queueing disciplines can be exercised. Assuming only independent Head of Line (HOL) service to an output from slot to slot, we derive the delay performance and saturation throughput. We then examine the accuracy of the assumption for different disciplines via extensive simulation. The FCFS HOL service discipline not only has almost completely identical results for simulation versus analysis, but also provides the best saturation throughput, fairness, and delay performance among all disciplines considered. The analysis shows that implementing packet priorities can significantly improve delay performance.

  11. Dynamic Bus Travel Time Prediction Models on Road with Multiple Bus Routes

    PubMed Central

    Bai, Cong; Peng, Zhong-Ren; Lu, Qing-Chang; Sun, Jian

    2015-01-01

    Accurate and real-time travel time information for buses can help passengers better plan their trips and minimize waiting times. A dynamic travel time prediction model for buses addressing the cases on road with multiple bus routes is proposed in this paper, based on support vector machines (SVMs) and Kalman filtering-based algorithm. In the proposed model, the well-trained SVM model predicts the baseline bus travel times from the historical bus trip data; the Kalman filtering-based dynamic algorithm can adjust bus travel times with the latest bus operation information and the estimated baseline travel times. The performance of the proposed dynamic model is validated with the real-world data on road with multiple bus routes in Shenzhen, China. The results show that the proposed dynamic model is feasible and applicable for bus travel time prediction and has the best prediction performance among all the five models proposed in the study in terms of prediction accuracy on road with multiple bus routes. PMID:26294903

  12. Dynamic Bus Travel Time Prediction Models on Road with Multiple Bus Routes.

    PubMed

    Bai, Cong; Peng, Zhong-Ren; Lu, Qing-Chang; Sun, Jian

    2015-01-01

    Accurate and real-time travel time information for buses can help passengers better plan their trips and minimize waiting times. A dynamic travel time prediction model for buses addressing the cases on road with multiple bus routes is proposed in this paper, based on support vector machines (SVMs) and Kalman filtering-based algorithm. In the proposed model, the well-trained SVM model predicts the baseline bus travel times from the historical bus trip data; the Kalman filtering-based dynamic algorithm can adjust bus travel times with the latest bus operation information and the estimated baseline travel times. The performance of the proposed dynamic model is validated with the real-world data on road with multiple bus routes in Shenzhen, China. The results show that the proposed dynamic model is feasible and applicable for bus travel time prediction and has the best prediction performance among all the five models proposed in the study in terms of prediction accuracy on road with multiple bus routes. PMID:26294903

  13. Bullying and Aggression on the School Bus: School Bus Drivers' Observations and Suggestions

    ERIC Educational Resources Information Center

    deLara, Ellen

    2008-01-01

    Every school day bus drivers are responsible for transporting children safely over many miles, yet they are rarely polled for their opinions or contributions to school safety. School bus drivers are in a unique position to inform the discussion on aggressive behavior during the school day. This exploratory study collected information from school…

  14. Sexual Harassment on the School Bus: Supporting and Preparing Bus Drivers to Respond Appropriately

    ERIC Educational Resources Information Center

    Allen, Melissa; Young, Ellie L.; Ashbaker, Betty Y.; Heaton, Emily; Parkinson, Marisa

    2003-01-01

    Sexual harassment is commonplace in schools, particularly among adolescents. Although information on this topic is typically gathered from students and teachers, this study collected information from school bus drivers. Based on feedback from 58 school bus drivers, 39 (67%) reported observing students making sexual comments or jokes. Almost half…

  15. Fuel Cell Bus Takes a Starring Role in the BurbankBus Fleet (Fact Sheet)

    SciTech Connect

    Not Available

    2010-05-01

    This fact sheet reports on the City of Burbank, California's fuel cell bus demonstration project and the U.S. Department of Energy's (DOE) involvement. Included are specifications for the fuel cell bus and information about its operation. BurbankBus, the city's mass transit entity, received a grant from the California Air Resources Board to fund its zero-emission bus demonstration and is collaborating with DOE's Fuel Cell Technologies Program to evaluate the bus performance. DOE's National Renewable Energy Laboratory will collect and analyze performance and operations data for at least one year. Researchers will use the data to better understand the technology and determine future development work. In addition, demonstration information will help fleets make informed purchase decisions.

  16. [Tuberculosis microepidemic in a commuter bus].

    PubMed

    Yagi, T; Sasaki, Y; Yamagishi, F; Mizutani, F; Wada, A; Kuroda, F

    1999-06-01

    A tuberculosis microepidemic in a commuter bus was reported. Index patient was a 22-year-old woman who was an employee of an electronic company. An abnormal shadow was found on her chest roentgenogram during an annual medical check-up in June, 1996. As her sputum smear was Gaffky 6, she was admitted to our hospital for medication. Extraordinary examinations including PPD skin test and chest X-ray were carried out on 49 employees of the company in October, 1996. As the result of these examinations, the distribution of maximum diameters of erythema in PPD skin test showed bimodal distribution, and tuberculosis was discovered in two patients by Chest X-ray examination. Moreover, preventive administration of Isonicotinic acid hydrazide (INH) was indicated for 3 employees based on very strong skin reaction to PPD. These five employees were working separately from the index patient and had little contact with the patient in the work places, but using a same commuter bus. Therefore, we strongly suspect that they were infected from the index patient not in the work place but in the commuter bus. The air-conditioning of the bus used a closed recirculation system, hence insufficient ventilation in the bus contributed to the spread of tuberculosis infection. PMID:10423962

  17. The Effects of Active Queue Management and Explicit Congestion Notification on Web

    E-print Network

    Jeffay, Kevin

    1 The Effects of Active Queue Management and Explicit Congestion Notification on Web Performance study of the effects of active queue management (AQM) and explicit congestion notification (ECN saturation levels without significant degradation in user-perceived performance. I. INTRODUCTION

  18. Multiclass queueing systems in heavy traffic: an asymptotic approach based on distributional and conservation laws

    E-print Network

    Bertsimas, Dimitris J.

    We propose a new approach to analyze multiclass queueing systems in heavy traffic based on what we consider as fundamental laws in queueing systems, namely distributional and conservation laws. Methodologically, we extend ...

  19. Statistical Analysis of Bus Networks in India

    E-print Network

    Chatterjee, Atanu; Ramadurai, Gitakrishnan

    2015-01-01

    Through the past decade the field of network science has established itself as a common ground for the cross-fertilization of exciting inter-disciplinary studies which has motivated researchers to model almost every physical system as an interacting network consisting of nodes and links. Although public transport networks such as airline and railway networks have been extensively studied, the status of bus networks still remains in obscurity. In developing countries like India, where bus networks play an important role in day-to-day commutation, it is of significant interest to analyze its topological structure and answer some of the basic questions on its evolution, growth, robustness and resiliency. In this paper, we model the bus networks of major Indian cities as graphs in \\textit{L}-space, and evaluate their various statistical properties using concepts from network science. Our analysis reveals a wide spectrum of network topology with the common underlying feature of small-world property. We observe tha...

  20. Risk factors affecting fatal bus accident severity: Their impact on different types of bus drivers.

    PubMed

    Feng, Shumin; Li, Zhenning; Ci, Yusheng; Zhang, Guohui

    2016-01-01

    While the bus is generally considered to be a relatively safe means of transportation, the property losses and casualties caused by bus accidents, especially fatal ones, are far from negligible. The reasons for a driver to incur fatalities are different in each case, and it is essential to discover the underlying risk factors of bus fatality severity for different types of drivers in order to improve bus safety. The current study investigates the underlying risk factors of fatal bus accident severity to different types of drivers in the U.S. by estimating an ordered logistic model. Data for the analysis are retrieved from the Buses Involved in Fatal Accidents (BIFA) database from the USA for the years 2006-2010. Accidents are divided into three levels by counting their equivalent fatalities, and the drivers are classified into three clusters by the K-means cluster analysis. The analysis shows that some risk factors have the same impact on different types of drivers, they are: (a) season; (b) day of week; (c) time period; (d) number of vehicles involved; (e) land use; (f) manner of collision; (g) speed limit; (h) snow or ice surface condition; (i) school bus; (j) bus type and seating capacity; (k) driver's age; (l) driver's gender; (m) risky behaviors; and (n) restraint system. Results also show that some risk factors only have impact on the "young and elder drivers with history of traffic violations", they are: (a) section type; (b) number of lanes per direction; (c) roadway profile; (d) wet road surface; and (e) cyclist-bus accident. Notably, history of traffic violations has different impact on different types of bus drivers. PMID:26513334

  1. Understanding bus travel time variation using AVL data

    E-print Network

    Gerstle, David G

    2012-01-01

    The benefits of bus automatic vehicle location (AVL) data are well documented (see e.g., Furth et al. (2006)), ranging from passenger-facing applications that predict bus arrival times to service-provider-facing applications ...

  2. The crew activity planning system bus interface unit

    NASA Technical Reports Server (NTRS)

    Allen, M. A.

    1979-01-01

    The hardware and software designs used to implement a high speed parallel communications interface to the MITRE 307.2 kilobit/second serial bus communications system are described. The primary topic is the development of the bus interface unit.

  3. Evaluation of bus priority strategies for BRT operations

    E-print Network

    Matías Alemán, Anna C

    2013-01-01

    Bus Rapid Transit (BRT) uses strategies such as exclusive bus lanes, off-vehicle fare collection, high quality vehicles and stations, signal priority, among others. Transit Signal Priority (TSP) is frequently seen as an ...

  4. Queueing Systems 0 (1997) ?--? 1 Large Deviations Ordering of Point Processes in some

    E-print Network

    Massoulié, Laurent

    1997-01-01

    Queueing Systems 0 (1997) ?--? 1 Large Deviations Ordering of Point Processes in some Queueing/D/1 queues along fixed routes. For the so­called strong variability ordering we show that point processes remain smooth as they proceed through a tandem of quasi­saturated (i.e., loaded to 1) M+\\Delta/D/1

  5. Measuring Queue Capacities of IEEE 802.11 Wireless Access Points

    E-print Network

    Claypool, Mark

    for externally estimating the queue capacity for a wireless AP. APQ determines the AP saturation point, measures the baseline delay, induces the saturation rate to measure the delay with a full AP queue and computes degraded Quality of Service when a large AP queue saturates due to high concurrent flows with a high

  6. Input Versus Output Queueing on a Space-Division Pack& Switch

    E-print Network

    . Input queues, on the other hand, saturate at a utilization that depends on N, but is approximately (2Input Versus Output Queueing on a Space-Division Pack& Switch Abstract-Two simple models of queueing on an N X N space-division packetswitchare examined. The switch operates synchronously with fixed

  7. MCP: Few Bits for Fairing and Small Queues in the Stable State

    E-print Network

    Gorinsky, Sergey

    MCP: Few Bits for Fairing and Small Queues in the Stable State Maxim Podlesny and Sergey Gorinsky) and other existing protocols inflates the end-to-end delays by building up queues at bottleneck links. In this paper, we investigate Multimodal Control Protocol (MCP) designed to maintain low queues after converging

  8. Queue Back-Pressure Random Access in Multi-Hop Wireless Networks: Optimality and Stability

    E-print Network

    Stolyar, Alexander

    the saturation throughput region. Simulation comparison of QBRA and the queue oblivious random access algorithms1 Queue Back-Pressure Random Access in Multi-Hop Wireless Networks: Optimality and Stability is to devise distributed algorithms for utility-optimal end-to-end throughput allocation and queueing stability

  9. Modeling Queueing and Channel Access Delay in Unsaturated IEEE 802.11 Random Access MAC

    E-print Network

    Sikdar, Biplab

    1 Modeling Queueing and Channel Access Delay in Unsaturated IEEE 802.11 Random Access MAC based an analytic model for evaluating the queueing delays and channel access times at nodes in wireless networks closed form expressions for obtaining the delay and queue length characteristics and models each node

  10. Stabilizing Queues in Large-scale Networks Yi Fan, Zhong-Ping Jiang, and Hao Zhang

    E-print Network

    Panwar, Shivendra S.

    Stabilizing Queues in Large-scale Networks Yi Fan, Zhong-Ping Jiang, and Hao Zhang Abstract-- We is also presented to counteract arbitrary network delays. Index Terms-- Bottleneck queue regulation of decentralized output-port queue regulation at each node due to its important impact on the quality of service

  11. Queue Management as a DoS counter-measure? Daniel Boteanu1

    E-print Network

    Fernandez, José M.

    Queue Management as a DoS counter-measure? Daniel Boteanu1 , Jos´e M. Fernandez1 , John McHugh2 study the performance of timeout-based queue management practices in the context of flood denial become unavailable and Quality of Service (QoS) degradation attacks. While these queue management

  12. A Complexity O(1) Priority Queue for Event Driven Molecular Dynamics Simulations

    E-print Network

    Gerald Paul

    2006-06-26

    We propose and implement a priority queue suitable for use in event driven molecular dynamics simulations. All operations on the queue take on average O(1) time per collision. In comparison, previously studied queues for event driven molecular dynamics simulations require O(log $N$) time per collision for systems of $N$ particles.

  13. IOE 616 Queueing Theory Fall, 2002 Instructor: Professor Robert L. Smith

    E-print Network

    Smith, Robert L.

    .5 Applications to the M/M/1, M/G/1, R: 5.6 and G/M/m Queues Little's Formula R: 5.5 Continuous Time Markov R: 5.8 Chains and Markovian Queues Transforms and Transient K: Appendix I Behavior of the M/M/1 Queue Birth

  14. A MAX-ALGEBRA APPROACH TO MODELING AND SIMULATION OF TANDEM QUEUEING SYSTEMS

    E-print Network

    Krivulin, Nikolai K.

    A MAX-ALGEBRA APPROACH TO MODELING AND SIMULATION OF TANDEM QUEUEING SYSTEMS Nikolai K. Krivulin St.Petersburg State University Abstract. Max-algebra models of tandem single-server queueing systems with both finite of queueing systems, algebra models arise naturally from the recursive equations of the Lindley type, which

  15. Bounds for the Tail Distribution in a Queue with the Superposition of General Periodic Markov Sources

    E-print Network

    Ishizaki, Fumio

    Bounds for the Tail Distribution in a Queue with the Superposition of General Periodic Markov for the asymptotic tail distribution in a queue whose arrival process is a superposition of general periodic Markov Introduction Estimating the cell loss probability or the tail distri- bution of the queue length in ATM

  16. Aircraft/stores data bus networks

    NASA Astrophysics Data System (ADS)

    Flanagan, Richard A.; Simpson, Damon G.

    The integration of data bus military standard MIL-STD-1553 into an aircraft stores management system is unique. The number of remote terminals connected to the network is not constant. Weapons and their remote terminals are physically separated from the network during normal operation. This creates dynamic changes in the electrical loading of the network. Laboratory network integration tests were performed for both fighter and bomber single level networks. Single and multiple stores releases were simulated. Test results allow designers to understand the effects of coupler spacing, stub length and weapon releases on the performance of stores data bus networks.

  17. Analysis of a diesel-electric hybrid urban bus system

    SciTech Connect

    Marr, W.W.; Sekar, R.R.; Ahlheim, M.C.

    1993-08-01

    A hybrid bus powered by a diesel engine and a battery pack has been analyzed over an idealized bus-driving cycle in Chicago. Three hybrid configurations, two parallel and one series, have been evaluated. The results indicate that the fuel economy of a hybrid bus, taking into account the regenerative braking, is comparable with that of a conventional diesel bus. Life-cycle costs are slightly higher because of the added weight and cost of the battery.

  18. Analysis of a diesel-electric hybrid urban bus system

    NASA Astrophysics Data System (ADS)

    Marr, W. W.; Sekar, R. R.; Ahlheim, M. C.

    A hybrid bus powered by a diesel engine and a battery pack was analyzed over an idealized bus-driving cycle in Chicago. Three hybrid configurations, two parallel and one series, were evaluated. The results indicate that the fuel economy of a hybrid bus, taking into account the regenerative braking, is comparable with that of a conventional diesel bus. Life-cycle costs are slightly higher because of the added weight and cost of the battery.

  19. Yet Another School Bus Tragedy Proves Drivers Need More Training.

    ERIC Educational Resources Information Center

    Shannon, James W., Jr.

    1983-01-01

    A March 1982 Jonesboro, Arkansas, school bus accident in which nine people were killed has rekindled the debate over school bus safety, says the author. The article discusses briefly the opposition historically between school bus manufacturers and safety advocates and presents cost-benefit arguments concerning mandatory seat-belt installation.…

  20. Development and Implementation of a Bus Driver Training Program.

    ERIC Educational Resources Information Center

    Buchovecky, John G.

    A bus driver training program was developed and implemented in a rural school district in an effort to improve the driving skills of the bus drivers. The program was tailored to meet the needs of the bus drivers and utilized various community agencies for demonstration and teaching purposes. The subject areas included in the program were driver…

  1. Improvement of Multiprocessing Performance by Using Optical Centralized Shared Bus

    E-print Network

    Chen, Ray

    Improvement of Multiprocessing Performance by Using Optical Centralized Shared Bus Xuliang Han, Ray changed from the simple shared bus to the complicated switched medium. However, the switched medium is an indirect network. It cannot support multicast/broadcast as effectively as the shared bus. Besides

  2. 32 CFR 935.138 - Motor bus operation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Motor bus operation. 935.138 Section 935.138...CODE Motor Vehicle Code § 935.138 Motor bus operation. Each person operating a motor bus on Wake Island shall— (a) Keep its...

  3. 45 CFR 1310.17 - Driver and bus monitor training.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Driver and bus monitor training. 1310.17 Section...Requirements § 1310.17 Driver and bus monitor training. (a) Each...of road performance; and (2) before bus monitors assigned to vehicles used to...

  4. 49 CFR 374.317 - Identification-bus and driver.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Identification-bus and driver. 374.317 Section 374.317 Transportation...Passenger Service § 374.317 Identification—bus and driver. Each bus and driver providing service shall be identified in...

  5. Research on a Queue Scheduling Algorithm in Wireless Communications Network

    NASA Astrophysics Data System (ADS)

    Yang, Wenchuan; Hu, Yuanmei; Zhou, Qiancai

    This paper proposes a protocol QS-CT, Queue Scheduling Mechanism based on Multiple Access in Ad hoc net work, which adds queue scheduling mechanism to RTS-CTS-DATA using multiple access protocol. By endowing different queues different scheduling mechanisms, it makes networks access to the channel much more fairly and effectively, and greatly enhances the performance. In order to observe the final performance of the network with QS-CT protocol, we simulate it and compare it with MACA/C-T without QS-CT protocol. Contrast to MACA/C-T, the simulation result shows that QS-CT has greatly improved the throughput, delay, rate of packets' loss and other key indicators.

  6. Parallel discrete-event simulation of FCFS stochastic queueing networks

    NASA Technical Reports Server (NTRS)

    Nicol, David M.

    1988-01-01

    Physical systems are inherently parallel. Intuition suggests that simulations of these systems may be amenable to parallel execution. The parallel execution of a discrete-event simulation requires careful synchronization of processes in order to ensure the execution's correctness; this synchronization can degrade performance. Largely negative results were recently reported in a study which used a well-known synchronization method on queueing network simulations. Discussed here is a synchronization method (appointments), which has proven itself to be effective on simulations of FCFS queueing networks. The key concept behind appointments is the provision of lookahead. Lookahead is a prediction on a processor's future behavior, based on an analysis of the processor's simulation state. It is shown how lookahead can be computed for FCFS queueing network simulations, give performance data that demonstrates the method's effectiveness under moderate to heavy loads, and discuss performance tradeoffs between the quality of lookahead, and the cost of computing lookahead.

  7. Simple queueing model applied to the city of Portland

    SciTech Connect

    Simon, P.M.; Nagel, K. |

    1998-07-31

    The authors present a simple traffic micro-simulation model that models the effects of capacity cut-off, i.e. the effect of queue built-up when demand is exceeding capacity, and queue spillback, i.e. the effect that queues can spill back across intersections when a congested link is filled up. They derive the model`s fundamental diagrams and explain it. The simulation is used to simulate traffic on the emme/2 network of the Portland (Oregon) metropolitan region (20,000 links). Demand is generated by a simplified home-to-work assignment which generates about half a million trips for the AM peak. Route assignment is done by iterative feedback between micro-simulation and router. Relaxation of the route assignment for the above problem can be achieved within about half a day of computing time on a desktop workstation.

  8. Bus Maintenance is a Sound Investment.

    ERIC Educational Resources Information Center

    American School Board Journal, 1981

    1981-01-01

    Preventive school bus maintenance to reduce long-term costs should include daily visual inspections by drivers, frequent checks by mechanics, and comprehensive inspections every 5,000 miles. Mechanics recommend checking tail lights, batteries, brakes, lug nuts, leaf springs, tail pipes, and exhaust pipe hangers. (RW)

  9. x Objects and Services x Bus Arbitration

    E-print Network

    Kozak, Victor R.

    CAN Data Link Layer © CiA The CAN data link layer is standardized in ISO 11898. The data link layer-serialization). © CiA x Am Weichselgarten 26 x D-91058 Erlangen x headquarters@can-cia.de #12;Broadcast Communication) Frame I Local Intelligence Local Intelligence Local Intelligence Local Intelligence bus lines © CiA

  10. School Bus Accidents: Reducing Incidents and Injuries

    ERIC Educational Resources Information Center

    Mahoney, Daniel

    2009-01-01

    The number of children injured in nonfatal school bus accidents annually is more than double the number previously estimated. In Ohio alone, approximately 20,800 children younger than 18 were occupants of school buses that were involved in crashes in 2003 and 2004 (McGeehan 2007). Among those children, most had minor or no injuries. However, there…

  11. Mission Services Evolution Center Message Bus

    NASA Technical Reports Server (NTRS)

    Mayorga, Arturo; Bristow, John O.; Butschky, Mike

    2011-01-01

    The Goddard Mission Services Evolution Center (GMSEC) Message Bus is a robust, lightweight, fault-tolerant middleware implementation that supports all messaging capabilities of the GMSEC API. This architecture is a distributed software system that routes messages based on message subject names and knowledge of the locations in the network of the interested software components.

  12. FUEL CELL BUS DEMONSTRATION IN MEXICO CITY

    EPA Science Inventory

    The report discusses the performance of a cull-size, zero-emission, Proton Exchange Membrane (PEM) fuel-cell-powered transit bus in the atmospheric environment of Mexico City. To address the air quality problems caused by vehicle emissions in Mexico City, a seminar on clean vehic...

  13. Energy DataBus (Fact Sheet)

    SciTech Connect

    Not Available

    2013-07-01

    NREL has developed the Energy DataBus, an open-sourced software that collects massive amounts of energy-related data at second-to-second intervals; stores it in a massive, scalable database; and turns it into useful information.

  14. Bus 54 -- Where are you? A school bus intelligent information system

    SciTech Connect

    Truett, L.F.; Moore, S.; Tonn, B.; Conley, T.

    1998-07-01

    Although major accidents involving school buses are rare (only about 0.3% of all fatal crashes since 1986 are classified as school-bus-related), even minor accidents and breakdowns cause a great deal of parental anxiety. The objective of this research is to design an efficient, cost-effective, accurate, and secure system that will track individual school buses and communicate appropriate information to the school system`s central administration unit, to the school transportation administrator, and to parents of children on the bus. The greatest benefit of the proposed information system is that parents and officials can always know the location and condition (these conditions would vary depending on the needs of a particular school system) of the school buses. In case of an accident or mechanical problem, when emergency crews are needed, they can be dispatched almost immediately with a good understanding of the problem and the exact location of the bus. In addition to being able to track the bus while the child is on board, parents will be able to determine the location of their child`s bus prior to its arrival in the morning in order to prevent the child from needing to wait outside in inclement weather. The information available to parents can also be expanded to include maps of limited routes (e.g., snow routes). Basically, the Bus 54 concept consists of a bus component and a central data processing unit. Each bus will be outfitted with a global positioning satellite (GPS) device, a wireless communication device, and wireless data communication service. The central data processing unit will receive and process information from the buses and provide information access to parents and officials via an Internet link.

  15. Numerical study of urban traffic flow with dedicated bus lane and intermittent bus lane

    NASA Astrophysics Data System (ADS)

    Zhu, H. B.

    2010-08-01

    Based on the cellular automaton traffic flow model and the concept of public transport priority, a two-lane traffic model with an intermittent bus lane is proposed and the properties of urban traffic flow are studied. The cases of traffic with a dedicated bus lane (DBL), an intermittent bus lane (IBL) and an ordinary two-lane traffic are simulated, and comparisons in the form of the fundamental diagrams and the velocity-density profiles are made between them. It is shown that the DBL has the advantage of freeing buses from traffic interference and also has the disadvantage of disrupting traffic, the IBL is more efficient in improving the bus flow than ordinary two-lane traffic and maintaining the car flow at a higher level at the same time than the DBL, while the ordinary two-lane traffic suppresses public transportation and is not advantageous in easing urban traffic congestion. Also it is indicated that the DBL is only appropriate for low traffic flow in a two-lane traffic system, and this limitation can be partly overcome by opening the bus lane to general traffic intermittently when the bus lane is not in use by buses.

  16. 58. VIEW OF SIGNAL BUS SECTION NUMBER 2 LOCATED OVER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    58. VIEW OF SIGNAL BUS SECTION NUMBER 2 LOCATED OVER THE CONTROL ROOM MEZZANINE IN THE SIGNAL POWER CONDITIONING ROOM. BUS IS A HEAVY COPPER BAR APPROXIMATELY 1/2" BY 4" WHICH CONDUCTS POWER THROUGHOUT THE POWER PLANT. BUS ARE PROTECTED BY A BRICK AND SOAPSTONE HOUSING. OPENINGS FOR INSPECTION AND ACCESS WOULD NORMALLY BE PROTECTED BY GLASS DOORS. THE BUS WOULD BE SUPPORTED ON INSULATORS WITHIN THE BRICK CHAMBER. BUS WAS REMOVED AND SALVAGED WHEN THE STATION WAS ABANDONED. THE OBJECT IN THE TOP CENTER OF THE PHOTOGRAPH IS A POTENTIAL TRANSFORMER USED TO REDUCE BUS POTENTIAL OF 2200 VOLTS TO LOW VOLTAGES SAFE FOR USE IN CONTROL ROOM CIRCUITRY. POTENTIAL TRANSFORMERS ARE PRECISION DEVICES WHICH PRODUCE AN ACCURATE LOW VOLTAGE ANALOG OF THE HIGH VOLTAGE ON THE BUS. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  17. Priorities for an age-friendly bus system.

    PubMed

    Broome, Kieran; Worrall, Linda; McKenna, Kryss; Boldy, Duncan

    2010-09-01

    This article presents the results of a study on the barriers and facilitators to bus use for people aged 60 or older. Two complementary methodologies, nominal group technique and focussed ethnography, were used to identify barriers and facilitators and rank their importance. Two sample sites from Queensland, Australia, were selected, with 227 people participating in the nominal group technique and 40 people participating in the focussed ethnography component. Seven priorities for age-friendly bus systems emerged from the data: vehicle entrance/exit; bus driver friendliness and helpfulness; timetables and scheduling of buses; bus stop locations; pedestrian infrastructure; information and training for older people; and bus routes and destinations. These findings will assist researchers, policy makers, and transport providers to set evidence-based strategic directions for creating age-friendly bus systems. Both methods provide complementary perspectives on bus usability, which could not be gained from either method alone. PMID:20731892

  18. Dynamic Pricing and Queue Stability in Wireless Random Access Games

    E-print Network

    Alpcan, Tansu

    1 Dynamic Pricing and Queue Stability in Wireless Random Access Games Yunus Sarikaya, Tansu Alpcan the underlying user incentives, we make use of the conceptual framework of noncooperative game theory to obtain of the game including existence and uniqueness of Nash equilibrium point, convergence dynamics, and robustness

  19. Tracking Human Queues Using Single-Point Signal Monitoring

    E-print Network

    Gruteser, Marco

    to the service area along with transmitting phones. Our strategy extracts unique features embedded in signal traces to infer the critical time points when a person reaches the head of the queue and finishes service-world processes. Research has shown, for example, how cellular call data records Permission to make digital

  20. ZEROSUM MARKOV GAMES AND WORSTCASE OPTIMAL CONTROL OF QUEUEING SYSTEMS

    E-print Network

    Route des Lucioles BP93, 06902 Sophia­Antipolis Cedex France Arie HORDIJK Dept. of Mathematics the best performance under worst­case behaviour of nature. The purpose of this paper is to present a survey. In the second part of the paper we present a survey on existing results on worst­case control of queues

  1. CE/CSE 5710: Modeling & Simulation Introduction to Queueing Theory

    E-print Network

    relationship can be derived: Ci = ti + Di + Si (1) where Ci is the departure time point of the i - th customer = Average customer arrival rate µ = Average customer service rate Recursive relationship: Wi = Wi-1 + Si-1 fulfilling a specific service to arriving customers who are waiting in a queue. The customer inter

  2. KalmanQueue: An Adaptive Approach to Virtual Queuing

    E-print Network

    Morrow, James A.

    4 Properties of a Good Model 5 5 Basic Queuing Theory: Is It Useful? 6 5.1 Queuing Theory in OurKalmanQueue: An Adaptive Approach to Virtual Queuing February 10, 2004 Abstract QuickPass is a virtual queuing system that allows some theme park customers to significantly cut down their waiting time

  3. Appointments in Care Pathways: the Geox Queue with Slot Reservations

    E-print Network

    Boucherie, Richard J.

    Appointments in Care Pathways: the Geox /D/1 Queue with Slot Reservations Maartje E. Zonderland by the increasing popularity of care pathways in outpa- tient clinics, where some patients complete a significant part of the path in one day, hospitals aim to optimize the flow of these patients by prioritizing them

  4. UNIVERSITY OF DEBRECEN HETEROGENEOUS FINITE-SOURCE RETRIAL QUEUES WITH

    E-print Network

    Sztrik, János

    with a finite number of heterogeneous sources of calls and a single non-reliable server, which means number of heterogeneous sources, non- reliable server, performance tool, performance and reliability], [37] where infinite-source non-reliable retrial queues were treated. In many practical situations

  5. Vertical Dimensioning: A Novel DRR Implementation for Efficient Fair Queueing

    E-print Network

    Papadias, Dimitris

    1 Vertical Dimensioning: A Novel DRR Implementation for Efficient Fair Queueing Spiridon Bakiras1 Feng Wang2 Dimitris Papadias2 Mounir Hamdi2 1 Department of Mathematics and Computer Science John Jay College of Criminal Justice, City University of New York (CUNY) 2 Department of Computer Science Hong Kong

  6. Analysis of fluid queues in saturation with additive decomposition

    E-print Network

    Telek, Miklós

    Analysis of fluid queues in saturation with additive decomposition Mikl´os Telek and Mikl´os V numerical procedures is the additive decomposition method proposed by Nail Akar and his colleagues. The additive decomposition method is based on a separation of the eigen- values of the characterizing matrix

  7. GPS Queues with Heterogeneous Traffic Classes Sem Borst,,

    E-print Network

    Boucherie, Richard J.

    GPS Queues with Heterogeneous Traffic Classes Sem Borst,, , Michel Mandjes, , Miranda van Uitert traffic classes are served in accordance with the Gen- eralized Processor Sharing (GPS) discipline. GPS of the light-tailed class for the situation where its GPS weight is larger than its traffic intensity. The GPS

  8. Simulation Model of Bus Rapid Transit

    NASA Astrophysics Data System (ADS)

    Gunawan, Fergyanto E.; Suharjito; Gunawan, Alexander A. S.

    2014-03-01

    Bus rapid transit system is modern solution for mass transportation system. The system, in comparison to the rail-based transportation system, is significantly cheaper and requires shorter development time, but lower performance. The BRT system performance strongly depends on variables related to station design and infrastructure. A numerical model offers an effective and efficient means to evaluate the system performance. This article offers a detailed numerical model on the basis of the discrete-event approach and demonstrates its application.

  9. Spacecraft design project multipurpose satellite bus MPS

    NASA Technical Reports Server (NTRS)

    Kellman, Lyle; Riley, John; Szostak, Michael; Watkins, Joseph; Willhelm, Joseph; Yale, Gary

    1990-01-01

    The thrust of this project was to design not a single spacecraft, but to design a multimission bus capable of supporting several current payloads and unnamed, unspecified future payloads. Spiraling costs of spacecraft and shrinking defense budgets necessitated a fresh look at the feasibility of a multimission spacecraft bus. The design team chose two very diverse and different payloads, and along with them two vastly different orbits, to show that multimission spacecraft buses are an area where indeed more research and effort needs to be made. Tradeoffs, of course, were made throughout the design, but optimization of subsystem components limited weight and volume penalties, performance degradation, and reliability concerns. Simplicity was chosen over more complex, sophisticated and usually more efficient designs. Cost of individual subsystem components was not a primary concern in the design phase, but every effort was made to chose flight tested and flight proven hardware. Significant cost savings could be realized if a standard spacecraft bus was indeed designed and purchased in finite quantities.

  10. 49 CFR 605.18 - Comments by private school bus operators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Comments by private school bus operators. 605.18... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.18 Comments by private school bus operators. Private school bus operators may file written comments on an...

  11. Communication design for multi-boards based on VME bus

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Song, Fazhi; Wei, Kai; Fu, Zhenxian

    2015-02-01

    As a widely used open-architecture computer bus ,VME bus is increasingly applied in military, aerospace, transportation and other large-scale control systems. Lithography, a very delicate and complicated integrated circuit manufacturing equipment, uses many circuit boards with VME interface in its control system, including one single-board computer, many movement control boards and one data acquisition board. This paper designs communication modules which include VME bus module and VME user-defined bus module for multi-boards in Lithography control system. VME bus module is designed for the communication between the single-board computer and movement control boards and VME user-defined bus is designed for the communication between movement control boards and data acquisition board. The experimental results demonstrate its effectiveness.

  12. Virtual queueing techniques for UBR+ service in ATM with fair access and minimum bandwidth guarantee

    SciTech Connect

    Siu, K.Y.; Wu, Y.; Ren, W.

    1998-11-01

    The ATM Forum is currently discussing the need for a new best-effort service called UBR+, which is an enhancement to the existing UBR service, to support data traffic. The objective of the UBR+ service is to provide each user with a minimum service rate guarantee and a fair access to any excess available bandwidth. In this paper, the authors present a new efficient scheme for supporting this service. The key advantage of the scheme is that it employs only FIFO queueing (instead of per-VC queueing) and admits simple implementation in ATM switches. The ideas involve a simple scheduling mechanism that is based on per-VC queueing and incorporate the virtual queueing technique that can efficiently emulate per-VC queueing on a shared FIFO queue. Simulation results are presented to show that the schemes can deliver almost ideal performance for supporting the new service requirements of UBR+.

  13. Generalized priority-queue network dynamics: Impact of team and hierarchy

    NASA Astrophysics Data System (ADS)

    Cho, Won-Kuk; Min, Byungjoon; Goh, K.-I.; Kim, I.-M.

    2010-06-01

    We study the effect of team and hierarchy on the waiting-time dynamics of priority-queue networks. To this end, we introduce generalized priority-queue network models incorporating interaction rules based on team-execution and hierarchy in decision making, respectively. It is numerically found that the waiting-time distribution exhibits a power law for long waiting times in both cases, yet with different exponents depending on the team size and the position of queue nodes in the hierarchy, respectively. The observed power-law behaviors have in many cases a corresponding single or pairwise-interacting queue dynamics, suggesting that the pairwise interaction may constitute a major dynamic consequence in the priority-queue networks. It is also found that the reciprocity of influence is a relevant factor for the priority-queue network dynamics.

  14. Queue Resource Reallocation Strategy for Traffic Systems in Scale-Free Network

    NASA Astrophysics Data System (ADS)

    Zhang, Shuai; Liang, Man-Gui; Jiang, Zhong-Yuan; Li, Hui-Jia

    2013-03-01

    In real communication systems, each node has a finite queue length to store packets due to physical constraints. In this paper, we propose a queue resource allocation strategy for traffic dynamics in scale-free networks. With a finite resource of queue, the allocation of queue length on node i is based on Bi, where Bi is the generalized betweenness centrality of node i. The overall traffic capacity of a network system can be evaluated by the critical packet generating rate (Rc). Through the use of the proposed queue allocation scheme for the shortest path protocol and efficient routing protocol, our strategy performs better than the uniform queue length allocation strategy, which is demonstrated by a larger value of the critical generating rate. We also give a method to estimate the network traffic capacity theoretically.

  15. Status of the IEEE P896 Future Backplane Bus

    SciTech Connect

    Gustavson, D.B.

    1983-10-01

    The IEEE P896 Future Backplane Bus project has been influenced by and has influenced FASTBUS and several other contemporary bus designs. This paper summarizes the current status of that project, which is directed toward the needs of modern 32-bit microprocessor systems with multiple processors. Some of the technology developed for P896 will be important for future non-ECL implementations of FASTBUS and other buses. In particular, new bus drivers and receivers should greatly improve the performance and reliability of backplane buses and cable buses. The current status of the P896 serial bus is also summarized.

  16. Use of the I2C Bus in Space Applications

    NASA Astrophysics Data System (ADS)

    Andersson, J.; Habinc, S.; Gaisler, J.; Furano, G.

    2009-05-01

    The two wire bidirectional I C-bus [1] has been proposed for use in space applications and the European Space Agency has recently expressed interest in evaluating I C for space sensor buses [2]. This paper contains an introduction to the I C-bus and gives an overview of its use. Additions to make the bus fault tolerant are discussed, as well as an alternative to the physical layer defined in the I C specification. The paper also describes SoC integration of I C IP cores as well as present and planned future, products from Aeroflex Gaisler that include support for the I C-bus.

  17. The SMART MIL-STD-1553 bus adapter hardware manual

    NASA Technical Reports Server (NTRS)

    Ton, T. T.

    1981-01-01

    The SMART Multiplexer Interface Adapter, (SMIA) a complete system interface for message structure of the MIL-STD-1553, is described. It provides buffering and storage for transmitted and received data and handles all the necessary handshaking to interface between parallel 8-bit data bus and a MIL-STD serial bit stream. The bus adapter is configured as either a bus controller of a remote terminal interface. It is coupled directly to the multiplex bus, or stub coupled through an additional isolation transformer located at the connection point. Fault isolation resistors provide short circuit protection.

  18. Approximate Analysis of Queueing Networks with Markovian Arrival Processes and Phase Type Service

    E-print Network

    Strelen, Christoph

    Abstract Open queueing networks with Markovian arrival processes and phase type * *ser- vice to a combinatorial explosion law. * *Therefore exact methods will never suffice for all models, approximation

  19. Apparatus and method for managing digital resources by passing digital resource tokens between queues

    DOEpatents

    Crawford, H.J.; Lindenstruth, V.

    1999-06-29

    A method of managing digital resources of a digital system includes the step of reserving token values for certain digital resources in the digital system. A selected token value in a free-buffer-queue is then matched to an incoming digital resource request. The selected token value is then moved to a valid-request-queue. The selected token is subsequently removed from the valid-request-queue to allow a digital agent in the digital system to process the incoming digital resource request associated with the selected token. Thereafter, the selected token is returned to the free-buffer-queue. 6 figs.

  20. Apparatus and method for managing digital resources by passing digital resource tokens between queues

    DOEpatents

    Crawford, Henry J. (Berkeley, CA); Lindenstruth, Volker (El Cerrito, CA)

    1999-01-01

    A method of managing digital resources of a digital system includes the step of reserving token values for certain digital resources in the digital system. A selected token value in a free-buffer-queue is then matched to an incoming digital resource request. The selected token value is then moved to a valid-request-queue. The selected token is subsequently removed from the valid-request-queue to allow a digital agent in the digital system to process the incoming digital resource request associated with the selected token. Thereafter, the selected token is returned to the free-buffer-queue.

  1. 49 CFR 605.18 - Comments by private school bus operators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Comments by private school bus operators. 605.18 Section 605.18 Transportation...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.18 Comments by private...

  2. 49 CFR 571.220 - Standard No. 220; School bus rollover protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Standard No. 220; School bus rollover protection. 571.220 Section...571.220 Standard No. 220; School bus rollover protection. S1. Scope. ...establishes performance requirements for school bus rollover protection. S2....

  3. 77 FR 19132 - Federal Motor Vehicle Safety Standards; Bus Emergency Exits and Window Retention and Release

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-30

    ...Federal Motor Vehicle Safety Standards; Bus Emergency Exits and Window Retention and...Federal motor vehicle safety standard for bus emergency exits. First, based on a proposal...petition for rulemaking from the School Bus Manufacturers Technical Council...

  4. 75 FR 20034 - Over-the-Road Bus Accessibility Program Grants: Corrections

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-16

    ...Transit Administration Over-the-Road Bus Accessibility Program Grants: Corrections...FTA) Notice titled ``Over-the-Road Bus Accessibility Program Grants,'' extends...Special Warranty for the Over-the-Road Bus Accessibility Program that is most...

  5. Managing Student Behavior on the School Bus: A Key to Bus Safety

    ERIC Educational Resources Information Center

    American Federation of Teachers (NJ), 2007

    2007-01-01

    School buses are the safest form of mass transit in America. Every day, school buses travel through congested city traffic and on isolated country roads in all types of weather, safely transporting millions of children to and from school and school-related activities. Federal and state standards for school bus construction and maintenance and…

  6. Courses: Business Administration (BUS) Page 265Sonoma State University 2015-2016 Catalog Business Administration (BUS)

    E-print Network

    Ravikumar, B.

    negligence, contracts, product liability, and constitutional law, and reviews government regulations. The course emphasizes the sources, functions, and processes of law. It surveys a number of areas, including in the areas of consumer protection, antitrust, labor, and employment law. BuS 230A FinAnCiAL ACCounting (4

  7. When the Wheels on the Bus Go Round: Social Interactions on the School Bus

    ERIC Educational Resources Information Center

    Galliger, Courtney C.; Tisak, Marie S.; Tisak, John

    2009-01-01

    Children's social interactions are often dependent upon the setting or context in which they occur. The current study explored the school bus as a unique context for social interaction. One hundred and fifty-seven elementary school students (78 males and 79 females), in grades 3, 4, and 5, completed a questionnaire concerning the rate and types of…

  8. Resource Selection Using Execution and Queue Wait Time Predictions

    NASA Technical Reports Server (NTRS)

    Warren, Smith; Wong, Parkson; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    Computational grids provide users with many possible places to execute their applications. We wish to help users select where to run their applications by providing predictions of the execution times of applications on space shared parallel computers and predictions of when scheduling systems for such parallel computers will start applications. Our predictions are based on instance based learning techniques and simulations of scheduling algorithms. We find that our execution time prediction techniques have an average error of 37 percent of the execution times for trace data recorded from SGI Origins at NASA Ames Research Center and that this error is 67 percent lower than the error of user estimates. We also find that the error when predicting how long applications will wait in scheduling queues is 95 percent of mean queue wait times when using our execution time predictions and this is 57 percent lower than if we use user execution time estimates.

  9. Entrainment of a Synthetic Oscillator through Queueing Coupling

    NASA Astrophysics Data System (ADS)

    Hochendoner, Philip; Mather, William; Butzin, Nicholas; Ogle, Curtis

    2014-03-01

    Many biological systems naturally exhibit (often noisy) oscillatory patterns that are capable of being entrained by external stimuli, though the mechanism of entrainment is typically obscured by the complexity of native networks. A synthetic biology approach, where genetic programs are wired ``by hand,'' has proven useful in this regard. In the present study, we use a synthetic oscillator in Escherichia coli to demonstrate a novel and potentially widespread mechanism for biological entrainment: competition of proteins for degradation by common pathway, i.e. a entrainment by a bottleneck. To faithfully represent the discrete and stochastic nature of this bottleneck, we leverage results from a recent biological queueing theory, where in particular, the queueing theoretic concept of workload is discovered to simplify the analysis. NSF Award 1330180.

  10. Capacity-constrained traffic assignment in networks with residual queues

    SciTech Connect

    Lam, W.H.K.; Zhang, Y.

    2000-04-01

    This paper proposes a capacity-constrained traffic assignment model for strategic transport planning in which the steady-state user equilibrium principle is extended for road networks with residual queues. Therefore, the road-exit capacity and the queuing effects can be incorporated into the strategic transport model for traffic forecasting. The proposed model is applicable to the congested network particularly when the traffic demands exceeds the capacity of the network during the peak period. An efficient solution method is proposed for solving the steady-state traffic assignment problem with residual queues. Then a simple numerical example is employed to demonstrate the application of the proposed model and solution method, while an example of a medium-sized arterial highway network in Sioux Falls, South Dakota, is used to test the applicability of the proposed solution to real problems.

  11. Schedule and complex motion of shuttle bus induced by periodic inflow of passengers

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi; Naito, Yuichi

    2011-09-01

    We have studied the dynamic behavior of a bus in the shuttle bus transportation with a periodic inflow. A bus schedule is closely related to the dynamics. We present the modified circle map model for the dynamics of the shuttle bus. The motion of the shuttle bus depends on the loading parameter and the inflow period. The shuttle bus displays the periodic, quasi-periodic, and chaotic motions with varying both loading parameter and inflow rate.

  12. Spaceborne Fiber Optic Data Bus (SFODB)

    NASA Technical Reports Server (NTRS)

    Bretthauer, Joy W.; Chalfant, Chuck H.; Orlando, Fred J.; Parkerson, P.; Rezek, Ed; Sawyer, Marc

    1999-01-01

    Spaceborne Fiber Optic Data Bus (SFODB) is an IEEE 1393 compliant, gigabit per second, fiber optic network specifically designed to support the real-time, on-board data handling requirements of remote sensing spacecraft. The network is fault tolerant highly reliable, and capable of withstanding the rigors of launch and the harsh space environment. SFODB achieves this operational and environmental performance while maintaining the small size, light weight, and low power necessary for spaceborne applications. On December 9, 1998, SFODB was successfully demonstrated at NASA's Goddard Space Flight Center (GSFC).

  13. Interface Provides Standard-Bus Communication

    NASA Technical Reports Server (NTRS)

    Culliton, William G.

    1995-01-01

    Microprocessor-controlled interface (IEEE-488/LVABI) incorporates service-request and direct-memory-access features. Is circuit card enabling digital communication between system called "laser auto-covariance buffer interface" (LVABI) and compatible personal computer via general-purpose interface bus (GPIB) conforming to Institute for Electrical and Electronics Engineers (IEEE) Standard 488. Interface serves as second interface enabling first interface to exploit advantages of GPIB, via utility software written specifically for GPIB. Advantages include compatibility with multitasking and support of communication among multiple computers. Basic concept also applied in designing interfaces for circuits other than LVABI for unidirectional or bidirectional handling of parallel data up to 16 bits wide.

  14. 166 IEEE TRANSACTIONS ON INFORMATION THEORY, VOL. IT-31, NO. 2, MARCH 1985 On Queueing Problems in Random-Access

    E-print Network

    Kleinrock, Leonard

    find we cannot resist a good queue. Queue- ing theory is concerned with evaluating how badly customers in which no service capacity is idle when any work is to be done and in which no service capacity is wasted

  15. Queueing models for token and slotted ring networks. Thesis

    NASA Technical Reports Server (NTRS)

    Peden, Jeffery H.

    1990-01-01

    Currently the end-to-end delay characteristics of very high speed local area networks are not well understood. The transmission speed of computer networks is increasing, and local area networks especially are finding increasing use in real time systems. Ring networks operation is generally well understood for both token rings and slotted rings. There is, however, a severe lack of queueing models for high layer operation. There are several factors which contribute to the processing delay of a packet, as opposed to the transmission delay, e.g., packet priority, its length, the user load, the processor load, the use of priority preemption, the use of preemption at packet reception, the number of processors, the number of protocol processing layers, the speed of each processor, and queue length limitations. Currently existing medium access queueing models are extended by adding modeling techniques which will handle exhaustive limited service both with and without priority traffic, and modeling capabilities are extended into the upper layers of the OSI model. Some of the model are parameterized solution methods, since it is shown that certain models do not exist as parameterized solutions, but rather as solution methods.

  16. OneBusAway: Improving the Usability of Public Transit

    E-print Network

    Anderson, Richard

    OneBusAway: Improving the Usability of Public Transit Brian Ferris A dissertation submitted;#12;University of Washington Abstract OneBusAway: Improving the Usability of Public Transit Brian Ferris Public transit systems play an important role in providing transportation mobility to a significant portion

  17. 45 CFR 1310.17 - Driver and bus monitor training.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Driver and bus monitor training. 1310.17...Transportation Requirements § 1310.17 Driver and bus monitor training. ...this part. The agency must ensure that drivers who are hired to drive vehicles...

  18. 45 CFR 1310.17 - Driver and bus monitor training.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Driver and bus monitor training. 1310.17...Transportation Requirements § 1310.17 Driver and bus monitor training. ...this part. The agency must ensure that drivers who are hired to drive vehicles...

  19. 45 CFR 1310.17 - Driver and bus monitor training.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Driver and bus monitor training. 1310.17...Transportation Requirements § 1310.17 Driver and bus monitor training. ...this part. The agency must ensure that drivers who are hired to drive vehicles...

  20. 45 CFR 1310.17 - Driver and bus monitor training.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Driver and bus monitor training. 1310.17...Transportation Requirements § 1310.17 Driver and bus monitor training. ...this part. The agency must ensure that drivers who are hired to drive vehicles...

  1. 16. Bus Room (also known as Switch Gear Room), view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Bus Room (also known as Switch Gear Room), view to the southeast. An air circuit breaker compressor (visible in photograph number 2) was once attached to the main bus relay visible in the background of the photograph. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  2. Project space shuttle. Data bus evaluation laboratory test report

    NASA Technical Reports Server (NTRS)

    Dennis, G. R.

    1975-01-01

    A Data Bus Evaluation Laboratory (DBEL) facility has been established to test and evaluate space shuttle data bus hardware. Performance testing conducted on an in-house developed multiplex interface adapter for the purpose of evaluating DBEL test procedures, test hardware, and test software in a realistic test environment is described. Results are presented.

  3. School Bus Driver Instructional Program. Instructor's Guide--Advanced Unit.

    ERIC Educational Resources Information Center

    Department of Transportation, Washington, DC. National Highway Safety Bureau.

    Geared to behavioral objectives, the instruction is organized into programed units on emergency driving techniques, first aid, field trips, transporting exceptional students, detecting hazards, controlling the position of the bus, driving under special conditions, and preventive maintenance of the bus. Each unit is constructed around content…

  4. Connecticut Transit (CTTRANSIT) Fuel Cell Transit Bus: Preliminary Evaluation Results

    SciTech Connect

    Chandler, K.; Eudy, L.

    2008-10-01

    This report provides preliminary results from a National Renewable Energy Laboratory evaluation of a protoptye fuel cell transit bus operating at Connecticut Transit in Hartford. Included are descriptions of the planned fuel cell bus demonstration and equipment; early results and agency experience are also provided.

  5. Network Extender for MIL-STD-1553 Bus

    NASA Technical Reports Server (NTRS)

    Marcus, Julius; Hanson, T. David

    2003-01-01

    An extender system for MIL-STD-1553 buses transparently couples bus components at multiple developer sites. The bus network extender is a relatively inexpensive system that minimizes the time and cost of integration of avionic systems by providing a convenient mechanism for early testing without the need to transport the usual test equipment and personnel to an integration facility. This bus network extender can thus alleviate overloading of the test facility while enabling the detection of interface problems that can occur during the integration of avionic systems. With this bus extender in place, developers can correct and adjust their own hardware and software before products leave a development site. Currently resident at Johnson Space Center, the bus network extender is used to test the functionality of equipment that, although remotely located, is connected through a MILSTD- 1553 bus. Inasmuch as the standard bus protocol for avionic equipment is that of MIL-STD-1553, companies that supply MIL-STD-1553-compliant equipment to government or industry and that need long-distance communication support might benefit from this network bus extender

  6. Integrating timetabling and vehicle scheduling in public bus transportation

    E-print Network

    Utrecht, Universiteit

    Integrating timetabling and vehicle scheduling in public bus transportation A.P.R. van den Heuvel J The Netherlands #12;Integrating timetabling and vehicle scheduling in public bus transportation A.P.R. van den steps: network route design, timetable generation, the generation of vehicle schedules

  7. Riding the Bus: Symbol and Vehicle for Boundary Spanning

    ERIC Educational Resources Information Center

    Romero, Deborah

    2014-01-01

    In this reflective essay I examine the activity of a bus tour, organized as the result of an ongoing university and city partnership. I illustrate how riding the bus is not only symbolic for positionality in our society, but also how it can be a viable mechanism for initiating boundary spanning and promoting opportunities for place-based learning…

  8. Bullying on the School Bus: A Video Analysis

    ERIC Educational Resources Information Center

    Raskauskas, Juliana

    2005-01-01

    The purpose of this study was to assess the nature of bullying on the school bus. Videotapes were used to identify occurrences of bullying on buses of elementary school students. Incidents were reviewed for forms of bullying, fullness, presence of friends, and severity of acts. Results indicated that approximately two incidents occurred per bus

  9. Parents' Perceptions of the Rural School Bus Ride

    ERIC Educational Resources Information Center

    Ramage, Rob; Howley, Aimee

    2005-01-01

    This article reports findings from a study of the perceptions of parents about the experience of long bus rides on their children. Twenty-six parents, whose homes were located on the longest bus route in a rural Midwestern school district, provided interviews regarding the experiences of a total of 37 students. In the analysis of the interview…

  10. Bus-based best-practice and urban transport emissions

    NASA Astrophysics Data System (ADS)

    Enoch, Marcus Paul

    In Britain over recent years, transport has risen to the very top of the political agenda, partly because it is the fastest growing source of urban emissions. One politically attractive solution to this rapidly worsening problem, is 'improving public transport'. This thesis examines how the bus-the most widespread form of public transport-could be improved, and at how much these improvements would contribute to solving the emissions problem. The project was studied in two inter-related parts. The first part aimed to determine the factors necessary in forming the 'best possible' bus-based transport system by identifying and analysing a number of 'best-practice' bus systems in Europe and North America, using a case study approach. The second part then sought to quantify the effect on travel patterns and emissions that implementing this best possible bus-based transport system would have. This was done by modelling a series of possible scenarios with the START strategic transport model, and a modified version of the JET emissions inventory model. The City of Leicester was used as a modelling base. The study found that bus systems contributed most to reducing urban emissions where the needs of the bus passenger were made paramount, and where bus operators worked together with local government, local businesses etc. Even where these factors existed however, the effect of bus-based transport policies on levels of pollutants was found to be significant only when applied together with strong car restraint measures.

  11. Design of a Programmable Bus for Microprocessor-Based Systems

    E-print Network

    , microprocessor-based systems. 1. INTRODUCTION The outside environment parameters to be measured and processed/O bus is the industry standard architecture (ISA)[4]. Newer PCs actually use an additional port work as a bridge between the proposed bus system and the host PC. This system will provide the hardware

  12. Genetic algorithm for multiple bus line coordination on urban arterial.

    PubMed

    Yang, Zhen; Wang, Wei; Chen, Shuyan; Ding, Haoyang; Li, Xiaowei

    2015-01-01

    Bus travel time on road section is defined and analyzed with the effect of multiple bus lines. An analytical model is formulated to calculate the total red time a bus encounters when travelling along the arterial. Genetic algorithm is used to optimize the offset scheme of traffic signals to minimize the total red time that all bus lines encounter in two directions of the arterial. The model and algorithm are applied to the major part of Zhongshan North Street in the city of Nanjing. The results show that the methods in this paper can reduce total red time of all the bus lines by 31.9% on the object arterial and thus improve the traffic efficiency of the whole arterial and promote public transport priority. PMID:25663837

  13. Method and systems for a radiation tolerant bus interface circuit

    NASA Technical Reports Server (NTRS)

    Kinstler, Gary A. (Inventor)

    2007-01-01

    A bus management tool that allows communication to be maintained between a group of nodes operatively connected on two busses in the presence of radiation by transmitting periodically a first message from one to another of the nodes on one of the busses, determining whether the first message was received by the other of the nodes on the first bus, and when it is determined that the first message was not received by the other of the nodes, transmitting a recovery command to the other of the nodes on a second of the of busses. Methods, systems, and articles of manufacture consistent with the present invention also provide for a bus recovery tool on the other node that re-initializes a bus interface circuit operatively connecting the other node to the first bus in response to the recovery command.

  14. Finite-source M=M=S retrial queue with search for balking and impatient customers from the orbit

    E-print Network

    Sztrik, János

    Finite-source M=M=S retrial queue with search for balking and impatient customers from the orbit Keywords: Performance modeling Finite-source retrial queues Orbital search Balking customers Impatient-server finite- source retrial queue with search for customers in the orbit. The novelty of the investigation

  15. The Effects of Active Queue Management on Web Performance Long Le Jay Aikat Kevin Jeffay F. Donelson Smith

    E-print Network

    Jeffay, Kevin

    The Effects of Active Queue Management on Web Performance Long Le Jay Aikat Kevin Jeffay F://www.cs.unc.edu/Research/dirt ABSTRACT We present an empirical study of the effects of active queue man­ agement (AQM FIFO queue management. 2. For loads of 90% of link capacity or greater when ECN is not used, PI results

  16. IEEE TRANSACTIONS ON INFORMATION THEORY, VOL. 55, NO. 9, SEPTEMBER 2009 4087 Queue Back-Pressure Random Access in Multihop

    E-print Network

    Chiang, Mung

    the saturation throughput region. Simulation comparison of QBRA and the queue oblivious random-access algorithmsIEEE TRANSACTIONS ON INFORMATION THEORY, VOL. 55, NO. 9, SEPTEMBER 2009 4087 Queue Back is to devise distributed algorithms for utility-optimal end-to-end throughput allocation and queueing stability

  17. Evaluation of horizontal and vertical queueing models in relation to observed trajectory data in a signalized urban

    E-print Network

    Evaluation of horizontal and vertical queueing models in relation to observed trajectory data and uninterrupted flows, less is known about the accuracy of CTM or other macroscopic queueing models on urban road the appropri- ate queueing model dynamics for use in analysis and control of a large-scale network

  18. The Effects of Active Queue Management on Web Performance Long Le Jay Aikat Kevin Jeffay F. Donelson Smith

    E-print Network

    Jeffay, Kevin

    The Effects of Active Queue Management on Web Performance Long Le Jay Aikat Kevin Jeffay F://www.cs.unc.edu/Research/dirt ABSTRACT We present an empirical study of the effects of active queue man- agement (AQM FIFO queue management. 2. For loads of 90% of link capacity or greater when ECN is not used, PI results

  19. Cache-Aware Lock-Free Queues for Multiple Producers/Consumers and Weak Memory Consistency

    E-print Network

    Tsigas, Philippas

    Cache-Aware Lock-Free Queues for Multiple Producers/Consumers and Weak Memory Consistency Anders°as, Bor°as, SWEDEN 2 Department of Computer Science and Engineering, Chalmers University of Technology, 412 96 G¨oteborg, SWEDEN. Abstract. A lock-free FIFO queue data structure is presented in this paper

  20. Capacity of Multiservice Cellular Networks with TransmissionRate Control: A Queueing Analysis

    E-print Network

    Capacity of Multi­service Cellular Networks with Transmission­Rate Control: A Queueing Analysis the system is already saturated. This guarantees the quality of service of ongoing calls. Our first result and Statistics]: Queueing theory; C.2.1 [Computer Communication Networks]: Network Ar­ chitecutre and Design

  1. WQM: An Aggregation-aware Queue Management Scheme for IEEE 802.11n based Networks

    E-print Network

    Shihada, Basem

    WQM: An Aggregation-aware Queue Management Scheme for IEEE 802.11n based Networks Ahmad Showail, such as frame aggregation. We propose WQM, a queue management scheme customized for wireless networks. WQM to saturate the buffer. 1. INTRODUCTION Recent measurement studies have uncovered signifi- cant overbuffering

  2. A queueing network model of Oracle Parallel Uli Harder \\Lambda and Peter Harrison y

    E-print Network

    Imperial College, London

    A queueing network model of Oracle Parallel Server Uli Harder \\Lambda and Peter Harrison y July 7 and parallel server versions. A modified queueing network is used which is extended to include traditional saturation point for the number of concurrent transactions executing, as is observed in many systems

  3. A Method for Approximating the Variance of the Sojourn Times in Star-Shaped Queueing Networks

    E-print Network

    van der Mei, Rob

    in an open star-shaped queueing network, with a central processor-sharing (PS) node 0 and M 1 multi-server First-Come-First Served (FCFS) nodes. Each customer alternatingly visits the central node and one in an open star-shaped queueing network, where the customers represent EU-initiated transactions. The central

  4. Non-Threshold Equilibrium for Customers Joining an M/G/1 Queue Eitan Altman

    E-print Network

    customer can observe the length of the queue upon arrival. Customers are identical. The value of service is r and the cost of spending time in queue (or in service) is c per time unit. An arriving customer and denote by E(Rjj) the expected residual service time of the customer in service given that there are j

  5. Fair Operation of Multi-Server and Multi-Queue Systems School of Computer Science

    E-print Network

    Levy, Hanoch

    Fair Operation of Multi-Server and Multi-Queue Systems David Raz School of Computer Science Tel Brunswick, NJ, USA aviitzha@rutcor.rutgers.edu Hanoch Levy School of Computer Science Tel-Aviv University, computer systems). One of the ma- jor motivations behind common queue operation strategies is to grant fair

  6. A Resource-Allocation Queueing Fairness Measure School of Computer Science

    E-print Network

    Levy, Hanoch

    A Resource-Allocation Queueing Fairness Measure David Raz School of Computer Science Tel-Aviv University, Tel-Aviv, Israel davidraz@post.tau.ac.il Hanoch Levy School of Computer Science Tel, NJ, USA aviitzha@rutcor.rutgers.edu ABSTRACT Fairness is a major issue in the operation of queues

  7. Execution of queue-scheduled observations with the Gemini 8m telescopes

    E-print Network

    Execution of queue-scheduled observations with the Gemini 8m telescopes Phil Puxley Gemini 8m described. In this paper we discuss the philosophy and parameters which define its execution. Results from detailed simulations of the queue execution process are presented. Keywords: Gemini telescopes, telescope

  8. Distributed Queue-Length based Algorithms for Optimal End-to-End Throughput Allocation and Stability in Multi-hop Random Access

    E-print Network

    Stolyar, Alexander

    that QBRA ensures stability of the queues as long as nominal loads of the nodes are within the saturationDistributed Queue-Length based Algorithms for Optimal End-to-End Throughput Allocation and queueing stability. We consider a class of queue back-pressure random- access algorithms (QBRA), where

  9. Request queues for interactive clients in a shared file system of a parallel computing system

    DOEpatents

    Bent, John M.; Faibish, Sorin

    2015-08-18

    Interactive requests are processed from users of log-in nodes. A metadata server node is provided for use in a file system shared by one or more interactive nodes and one or more batch nodes. The interactive nodes comprise interactive clients to execute interactive tasks and the batch nodes execute batch jobs for one or more batch clients. The metadata server node comprises a virtual machine monitor; an interactive client proxy to store metadata requests from the interactive clients in an interactive client queue; a batch client proxy to store metadata requests from the batch clients in a batch client queue; and a metadata server to store the metadata requests from the interactive client queue and the batch client queue in a metadata queue based on an allocation of resources by the virtual machine monitor. The metadata requests can be prioritized, for example, based on one or more of a predefined policy and predefined rules.

  10. Bus industry market study. Report -- Task 3.2: Fuel cell/battery powered bus system

    SciTech Connect

    Zalbowitz, M.

    1992-06-02

    In support of the commercialization of fuel cells for transportation, Georgetown University, as a part of the DOE/DOT Fuel Cell Transit Bus Program, conducted a market study to determine the inventory of passenger buses in service as of December, 1991, the number of buses delivered in 1991 and an estimate of the number of buses to be delivered in 1992. Short term and long term market projections of deliveries were also made. Data was collected according to type of bus and the field was divided into the following categories which are defined in the report: transit buses, school buses, commercial non-transit buses, and intercity buses. The findings of this study presented with various tables of data collected from identified sources as well as narrative analysis based upon interviews conducted during the survey.

  11. The Wheels on the Bus Go “Buy Buy Buy”: School Bus Advertising Laws

    PubMed Central

    2012-01-01

    School buses, a practical necessity for millions of children, are at the center of new efforts to raise revenue. School bus advertising laws bring public health and commercialization concerns to the school setting. In doing so, they potentially expose school districts to First Amendment lawsuits. I examined various school bus advertising bills and laws. I reviewed First Amendment “forum analysis” as applied in the transit and school settings to clarify how this legal test may affect school districts subject to such laws. I have made recommendations for school districts to enact appropriate policies to ensure that such advertising does not undermine public health and to enable the districts to maintain control over their property. PMID:22742065

  12. Respiratory symptoms and lung function in bus drivers and mechanics.

    PubMed

    Zuskin, E; Mustajbegovic, J; Schachter, E N

    1994-12-01

    Acute and chronic respiratory symptoms as well as ventilatory capacity were studied in 116 bus drivers and 119 mechanics. Bus drivers and mechanics demonstrated a significantly higher prevalence of most chronic respiratory symptoms when compared to control workers. In particular, lower airway symptoms of chest tightness and dyspnea and upper airway symptoms of nasal catarrh were significantly more prevalent among drivers and mechanics than among controls. Bus drivers and mechanics who were smokers had significantly higher prevalences of respiratory symptoms than nonsmoking bus drivers. Bus drivers and mechanics employed for more than 10 years also exhibited higher frequencies of respiratory symptoms than those exposed for 10 years or less. Many of the workers complained of acute symptoms during the work shift. The ventilatory capacity data demonstrated lower values for all parameters, particularly FEF25, compared to control worker values as well as to predicted normal values, for bus drivers and mechanics who were smokers. Our data indicate that long-term employment in the transport industry of bus drivers and mechanics, particularly in combination with smoking, may be associated with the development of chronic respiratory symptoms and lung function impairment. PMID:7892828

  13. Status of the FASTBUS standard data bus

    SciTech Connect

    Larsen, R.S.

    1980-11-01

    FASTBUS is a new laboratory standard data bus intended for use in experimental data acquisition and control. The development of FASTBUS began with a feasibility study in 1976, and is presently at the development prototyping stage. The principal aims of the standard are to provide a factor of ten or more improvement in speed of data transfers over present systems, as well as to provide an architecture for systems containing multiple processors. Developmental prototypes now in progress include crates, backplanes, cooling devices, power supplies, test and diagnostic modules, and user modules. A sizeable software development effort is also underway. Several experiments have made commitments to use FASTBUS. A review of current work and potential applications is given. 10 figures.

  14. Bus bar electrical feedthrough for electrorefiner system

    DOEpatents

    Williamson, Mark; Wiedmeyer, Stanley G; Willit, James L; Barnes, Laurel A; Blaskovitz, Robert J

    2013-12-03

    A bus bar electrical feedthrough for an electrorefiner system may include a retaining plate, electrical isolator, and/or contact block. The retaining plate may include a central opening. The electrical isolator may include a top portion, a base portion, and a slot extending through the top and base portions. The top portion of the electrical isolator may be configured to extend through the central opening of the retaining plate. The contact block may include an upper section, a lower section, and a ridge separating the upper and lower sections. The upper section of the contact block may be configured to extend through the slot of the electrical isolator and the central opening of the retaining plate. Accordingly, relatively high electrical currents may be transferred into a glovebox or hot-cell facility at a relatively low cost and higher amperage capacity without sacrificing atmosphere integrity.

  15. Quantifying the Joint Impacts of Stop Locations, Signalized Intersections, and Traffic Conditions on Bus Travel Time

    E-print Network

    Bertini, Robert L.

    on Bus Travel Time Wei Feng Analyst Performance Management Chicago Transit Authority, Chicago, IL 60661, Signalized Intersections, and Traffic Conditions on Bus Travel Time ABSTRACT Quantifying factors that affect bus travel time along arterials is necessary to prioritize investments to reduce bus travel time

  16. Rethinking passive transport: bus fare exemptions and young people's wellbeing.

    PubMed

    Jones, Alasdair; Steinbach, Rebecca; Roberts, Helen; Goodman, Anna; Green, Judith

    2012-05-01

    Much recent public health research has emphasised the health impacts for young people of 'active travel' modes, typically defined as walking and cycling. Less research has focused on public transport modes. Drawing on qualitative data, we examine the links between bus travel and wellbeing in London, where young people currently have free bus travel. Our findings indicate that bus travel can be both a physically and socially active experience for young people. We suggest a more nuanced understanding of 'active travel' is now needed, alongside greater attention to urban public transport networks as key sites that impact on important determinants of wellbeing such as independent mobility and social inclusion. PMID:22321902

  17. Scaling of avalanche queues in directed dissipative sandpiles

    PubMed

    Tadic; Priezzhev

    2000-09-01

    Using numerical simulations and analytical methods we study a two-dimensional directed sandpile automaton with nonconservative random defects (concentration c) and varying driving rate r. The automaton is driven only at the top row and driving rate is measured by the number of added particles per time step of avalanche evolution. The probability distribution of duration of elementary avalanches at zero driving rate is exactly given by P1(t,c)=t(-3/2) exp[t ln(1-c)]. For driving rates in the interval 0 server queue in the queue theory. We study scaling properties of the busy period and dissipated energy of sequences of noninterrupted activity. In the limit c-->0 and varying linear system size L<1/c we find that at driving rates rqueues are characterized by a multifractal scaling and we determine the corresponding spectral functions. For L>1/c increasing the driving rate somewhat compensates for the energy losses at defects above the line r approximately sqrt[c]. The scaling exponents of the distributions in this region of phase diagram vary approximately linearly with the driving rate. Using properties of recurrent states and the probability theory we determine analytically the exact upper bound of the probability distribution of busy periods. In the case of conservative dynamics c=0 the probability of a continuous flow increases as F(infinity) approximately r(2) for small driving rates. PMID:11088824

  18. Development of a dual-field heteropoplar power converter

    NASA Technical Reports Server (NTRS)

    Eisenhaure, D. B.; Johnson, B.; Bliamptis, T.; St. George, E.

    1981-01-01

    The design and testing of a 400 watt, dual phase, dual rotor, field modulated inductor alternator is described. The system is designed for use as a flywheel to ac utility line or flywheel to dc bus (electric vehicle) power converter. The machine is unique in that it uses dual rotors and separately controlled fields to produce output current and voltage which are in phase with each other. Having the voltage and current in phase allows the power electronics to be made of simple low cost components. Based on analytical predictions and experimental results, development of a complete 22 kilowatt (30 Hp) power conversion system is recommended. This system would include power electronics and controls and would replace the inductor alternator with an improved electromagnetic conversion system.

  19. Spin-bus concept of spin quantum computing

    SciTech Connect

    Mehring, Michael; Mende, Jens

    2006-05-15

    We present a spin-bus concept of quantum computing where an electron spin S=1/2 acts as a bus qubit connected to a finite number N of nuclear spins I=1/2 serving as client qubits. Spin-bus clusters are considered as local processing units and may be interconnected with other spin-bus clusters via electron-electron coupling in a scaled up version. Here we lay the ground for the basic functional unit with long qubit registers, provide the theory and experimental verification of correlated qubit states, and demonstrate the Deutsch algorithm. Experiments were performed on a qubyte plus one nuclear spin in a solid state system.

  20. A Computer Assisted School Bus Routing Strategy: A Case Study.

    ERIC Educational Resources Information Center

    Hargroves, Bradely T.; Demetsky, Michael J.

    1981-01-01

    In suburban-rural Albemarle County (Virginia), computer assistance in evaluating manually-designed school bus routes helped increase efficiency in pupil transportation and reduce the number of routes, buses, and vacant seats. (RW)

  1. Analysis of Feeder Bus Network Design and Scheduling Problems

    PubMed Central

    Almasi, Mohammad Hadi; Karim, Mohamed Rehan

    2014-01-01

    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. PMID:24526890

  2. View of the current distribution "bus" atop switching cabinets within ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of the current distribution "bus" atop switching cabinets within the former transformer building. Looking northwest - Childs-Irving Hydroelectric Project, Childs System, Childs Powerhouse, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

  3. Improving high-frequency bus service reliability through better scheduling

    E-print Network

    Fattouche, Grâce

    2007-01-01

    Developing a schedule for high-frequency bus routes involves balancing the costs to the passengers in terms of passenger waiting time and in-vehicle time and the cost to the transit agency. Passengers are interested in ...

  4. CFD Investigation on Long-Haul Passenger Bus

    NASA Astrophysics Data System (ADS)

    Tan, C. F.; Tee, B. T.; Law, H. C.; Lim, T. L.

    2015-09-01

    Air flow distribution is one of the important factors that will influence the bus passenger comfort during long haul travel. Poor air flow distribution not only cause discomfort to the bus passenger but also influence their travel mode as well. The main purpose of this study is to investigate the air flow performance of the bus air-conditioning system through CFD simulation approach. A 3D CAD model of air ducts was drawn and hence analysed by using CFD software, namely ANSYS Fluent, to determine the airflow rate for every outlets of the air-conditioning system. The simulated result was then validated with experimental data obtained from prototype model of air duct. Based on the findings, new design concepts is proposed with the aim to meet the industry requirement as well as to improve the bus passenger comfort during long haul travel.

  5. Prototype thermal bus for manned Space Station compartments

    NASA Technical Reports Server (NTRS)

    Zentner, Ronald C.; Owen, James W.

    1986-01-01

    A summary is presented of NASA efforts, to February 1986, on development of an advanced thermal bus for manned spacecraft. Design details are described for a prototype to be tested in 1987 that includes a contact heat exchanger, an air cooling heat exchanger for manned cabin conditions, and an interface heat exchanger for transferring compartment heat loads to the Space Station Central Thermal Bus. The design and performance criteria defined for the thermal bus are outlined and results are reported from comparisons of the capabilities and operational costs of pumped water and two-phase evaporating/condensing heat transport concepts. The operating temperature, launch weight/thermal performance ratios, and power requirements of each concept are discussed, along with the critical technologies identified for use of a water/titanium two-phase thermal bus.

  6. Analysis of feeder bus network design and scheduling problems.

    PubMed

    Almasi, Mohammad Hadi; Mirzapour Mounes, Sina; Koting, Suhana; Karim, Mohamed Rehan

    2014-01-01

    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. PMID:24526890

  7. The School Bus Problem on Trees Adrian Bock1

    E-print Network

    Könemann, Jochen

    ending at s (bus routes) and assign each child w W to be the responsibility of some bus p(w) P) for every child the regret bound is respected, that is: dP (w, s) d(w, s) + R, where dP (w, s) is the distance from the child w to the school s on the walk p(w), and d(w, s) is the shortest distance from w

  8. Digital bus technology in new coal-fired plants

    SciTech Connect

    Blaney, J.; Murray, J.

    2007-10-15

    The main issues associated with including digital bus technology such as Foundation fieldbus, Profibus-DP or DeviceNet, in a coal-fired power plant are deciding which systems to install and determining how to implement it. Although still new, digital bus experiences to date have shown that the technology performs solidly and when wiring best practices are followed a significantly shorted commissioning cycle can be achieved. 1 fig., 2 tabs.

  9. Final Report for the H2Fuel Bus

    SciTech Connect

    Jacobs, W.D.

    1998-11-25

    The H2Fuel Bus is the world's first hydrogen-fueled electric hybrid transit bus. It was a project developed through a public/private partnership involving several leading technological and industrial organizations, with primary funding by the Department of Energy (DOE). The primary goals of the project are to gain valuable information on the technical readiness and economic viability of hydrogen fueled buses and to enhance the public awareness and acceptance of emerging hydrogen technologies.

  10. Characteristics of rainfall queues for rain attenuation studies over radio links at subtropical and equatorial Africa

    NASA Astrophysics Data System (ADS)

    Alonge, Akintunde A.; Afullo, Thomas J.

    2014-08-01

    Attenuation due to precipitation remains an important design factor in the future deployment of terrestrial and earth-space communication radio links. Largely, there are concerted efforts to understand the dynamics of precipitation in attenuation occurrence at subtropical, tropical, and equatorial region of Africa. In this deliberate approach, rainfall spikes pertaining to rain cells are conceptualized as distinct rain spike traffic over radio links, by applying queueing theory concepts. The queue distributions at Durban (29°52'S, 30°58'E) and Butare (2°36'S, 29°44'E)—respectively, of subtropical and equatorial climates—are investigated from distrometer measurements. The data sets at both sites are observed over four rain regimes: drizzle, widespread, shower, and thunderstorm. The queue parameters of service time and inter-arrival of rain spikes traffic at both regions are found to be Erlang-k distributed (Ek) and exponentially distributed (M), respectively. It is established that the appearance of rain rates over radio links invariably follows a First Come, First Served (FCFS), multi-server (s), infinite queue, and semi-Markovian process, designated as M/Ek/s/?/FCFS discipline. Modeled queue parameters at both regions are found to vary significantly over different regimes. However, these queue parameters over the entire data set suggest similar queue patterns at both sites. More importantly, power law relationships describing other queue-related parameters are formulated. The paper concludes by demonstrating an application of queueing theory for rainfall synthesis. The proposed technique will provide an alternative method of estimating rain cell sizes and rain attenuation over satellite and terrestrial links.

  11. Invasion percolation on a tree and queueing models.

    PubMed

    Gabrielli, A; Caldarelli, G

    2009-04-01

    We study the properties of the Barabási model of queuing [A.-L. Barabási, Nature (London) 435, 207 (2005); J. G. Oliveira and A.-L. Barabási, Nature (London) 437, 1251 (2005)] in the hypothesis that the number of tasks grows with time steadily. Our analytical approach is based on two ingredients. First we map exactly this model into an invasion percolation dynamics on a Cayley tree. Second we use the theory of biased random walks. In this way we obtain the following results: the stationary-state dynamics is a sequence of causally and geometrically connected bursts of execution activities with scale-invariant size distribution. We recover the correct waiting-time distribution PW(tau) approximately tau(-3/2) at the stationary state (as observed in different realistic data). Finally we describe quantitatively the dynamics out of the stationary state quantifying the power-law slow approach to stability both in single dynamical realization and in average. These results can be generalized to the case of a stochastic increase in the queue length in time with limited fluctuations. As a limit case we recover the situation in which the queue length fluctuates around a constant average value. PMID:19518199

  12. Applications of queueing theory to stochastic models of gene expression

    NASA Astrophysics Data System (ADS)

    Kulkarni, Rahul

    2012-02-01

    The intrinsic stochasticity of cellular processes implies that analysis of fluctuations (`noise') is often essential for quantitative modeling of gene expression. Recent single-cell experiments have carried out such analysis to characterize moments and entire probability distributions for quantities of interest, e.g. mRNA and protein levels across a population of cells. Correspondingly, there is a need to develop general analytical tools for modeling and interpretation of data obtained from such single-cell experiments. One such approach involves the mapping between models of stochastic gene expression and systems analyzed in queueing theory. The talk will provide an overview of this approach and discuss how theorems from queueing theory (e.g. Little's Law) can be used to derive exact results for general stochastic models of gene expression. In the limit that gene expression occurs in bursts, analytical results can be obtained which provide insight into the effects of different regulatory mechanisms on the noise in protein steady-state distributions. In particular, the approach can be used to analyze the effect of post-transcriptional regulation by non-coding RNAs leading to new insights and experimentally testable predictions.

  13. Queueing up for enzymatic processing: correlated signaling through coupled degradation

    PubMed Central

    Cookson, Natalie A; Mather, William H; Danino, Tal; Mondragón-Palomino, Octavio; Williams, Ruth J; Tsimring, Lev S; Hasty, Jeff

    2011-01-01

    High-throughput technologies have led to the generation of complex wiring diagrams as a post-sequencing paradigm for depicting the interactions between vast and diverse cellular species. While these diagrams are useful for analyzing biological systems on a large scale, a detailed understanding of the molecular mechanisms that underlie the observed network connections is critical for the further development of systems and synthetic biology. Here, we use queueing theory to investigate how ‘waiting lines' can lead to correlations between protein ‘customers' that are coupled solely through a downstream set of enzymatic ‘servers'. Using the E. coli ClpXP degradation machine as a model processing system, we observe significant cross-talk between two networks that are indirectly coupled through a common set of processors. We further illustrate the implications of enzymatic queueing using a synthetic biology application, in which two independent synthetic networks demonstrate synchronized behavior when common ClpXP machinery is overburdened. Our results demonstrate that such post-translational processes can lead to dynamic connections in cellular networks and may provide a mechanistic understanding of existing but currently inexplicable links. PMID:22186735

  14. Unhealthy and healthy weight control behaviours among bus operators

    PubMed Central

    French, S. A.

    2012-01-01

    Background Urban bus operators are an occupational group with high rates of overweight and obesity. Understanding methods bus operators use for weight control may be important; there may be increased risk for these workers to engage in less healthy weight management behaviours due to stressful working conditions. Aims To examine the prevalence of unhealthy and healthy weight control behaviours used by bus operators and examine associations between use of unhealthy weight control behaviours and work-related and sociodemographic variables. Methods Bus operators from four different transit garages were invited to complete a self-administered survey; height and weight were measured by research staff. Unhealthy and healthy weight control behaviours, work hours, work schedule and social support were measured with self-report items on the employee survey. Logistic regression analysis was conducted to estimate associations. Results Nearly 60% of bus operators endorsed at least one unhealthy method; over 50% reported skipping meals, 30% fasted and 10% reported taking diet pills in the past year. Bus operator gender, race, body mass index status and hours worked per week showed significant associations with using at least one unhealthy weight control behaviour. Conclusions Worksite interventions should emphasize the benefit of healthy eating and physical activity but should also address the use of less healthy methods for weight control for individuals employed in transportation occupations. PMID:22058193

  15. Exact dynamical state of the exclusive queueing process with deterministic hopping

    NASA Astrophysics Data System (ADS)

    Arita, Chikashi; Schadschneider, Andreas

    2011-11-01

    The exclusive queueing process (EQP) has recently been introduced as a model for the dynamics of queues that takes into account the spatial structure of the queue. It can be interpreted as a totally asymmetric exclusion process of varying length. Here we investigate the case of deterministic bulk hopping p=1 that turns out to be one of the rare cases where exact nontrivial results for the dynamical properties can be obtained. Using a time-dependent matrix product form we calculate several dynamical properties, e.g., the density profile of the system.

  16. Performance analysis of a scheme for concurrency/synchronization using queueing network models

    SciTech Connect

    Almeida, V.A.F.; Dowdy, L.W.

    1986-12-01

    Queueing network models have been used extensively to analyze performance of computer systems. However, queueing network models with product form solutions are not directly applicable to systems that process programs with internal concurrency/synchronization. An exact solution of system systems is often not feasible because of its large state space. Approximation techniques, based on queueing network theory, are presented which analyze the performance of closed systems with a specific scheme of concurrency/synchronization. The techniques are applicable to multitasking systems, distributed database systems, packet routing environments, and fork/join situations.

  17. DIMETHYL ETHER (DME)-FUELED SHUTTLE BUS DEMONSTRATION PROJECT

    SciTech Connect

    Elana M. Chapman; Shirish Bhide; Jennifer Stefanik; Howard Glunt; Andre L. Boehman; Allen Homan; David Klinikowski

    2003-04-01

    The objectives of this research and demonstration program are to convert a campus shuttle bus to operation on dimethyl ether, a potential ultra-clean alternative diesel fuel. To accomplish this objective, this project includes laboratory evaluation of a fuel conversion strategy, as well as, field demonstration of the DME-fueled shuttle bus. Since DME is a fuel with no lubricity (i.e., it does not possess the lubricating quality of diesel fuel), conventional fuel delivery and fuel injection systems are not compatible with dimethyl ether. Therefore, to operate a diesel engine on DME one must develop a fuel-tolerant injection system, or find a way to provide the necessary lubricity to the DME. In this project, they have chosen the latter strategy in order to achieve the objective with minimal need to modify the engine. Their strategy is to blend DME with diesel fuel, to obtain the necessary lubricity to protect the fuel injection system and to achieve low emissions. The bulk of the efforts over the past year were focused on the conversion of the campus shuttle bus. This process, started in August 2001, took until April 2002 to complete. The process culminated in an event to celebrate the launching of the shuttle bus on DME-diesel operation on April 19, 2002. The design of the system on the shuttle bus was patterned after the system developed in the engine laboratory, but also was subjected to a rigorous failure modes effects analysis (FMEA, referred to by Air Products as a ''HAZOP'' analysis) with help from Dr. James Hansel of Air Products. The result of this FMEA was the addition of layers of redundancy and over-pressure protection to the system on the shuttle bus. The system became operational in February 2002. Preliminary emissions tests and basic operation of the shuttle bus took place at the Pennsylvania Transportation Institute's test track facility near the University Park airport. After modification and optimization of the system on the bus, operation on the campus shuttle route began in early June 2002. However, the work and challenges continued as it has been difficult to maintain operability of the shuttle bus due to fuel and component difficulties. In late June 2002, the pump head itself developed operational problems (loss of smooth function) leading to excessive stress on the magnetic coupling and excessive current draw to operate. A new pump head was installed on the system to alleviate this problem and the shuttle bus operated successfully on DME blends from 10-25 vol% on the shuttle bus loop until September 30, 2002. During the period of operation on the campus loop, the bus was pulled from service, operated at the PTI test track and real-time emissions measurements were obtained using an on-board emissions analyzer from Clean Air Technologies International, Inc. Particulate emissions reductions of 60% and 80% were observed at DME blend ratios of 12 vol.% and 25 vol.%, respectively, as the bus was operated over the Orange County driving cycle. Increases in NOx, CO and HC emissions were observed, however. In summary, the conversion of the shuttle bus was successfully accomplished, particulate emissions reductions were observed, but there were operational challenges in the field. Nonetheless, they were able to demonstrate reliable operation of the shuttle bus on DME-diesel blends.

  18. A Cost Benefit Analysis of a V2G-Capable Electric School Bus Compared to a Traditional Diesel School Bus

    E-print Network

    Firestone, Jeremy

    Diesel Engine Efficiency 6.35 mpg µe Battery Efficiency 747 Wh/mile *These numbers represent the firstA Cost Benefit Analysis of a V2G-Capable Electric School Bus Compared to a Traditional Diesel analysis of a V2G-capable electric school bus compared to a traditional diesel school bus. Applied Energy

  19. Improvements to a queue and delay estimation algorithm utilized in video imaging vehicle detection systems 

    E-print Network

    Cheek, Marshall Tyler

    2007-09-17

    Video Imaging Vehicle Detection Systems (VIVDS) are steadily becoming the dominant method for the detection of vehicles at a signalized traffic approach. This research is intended to investigate the improvement of a queue and delay estimation...

  20. Analyzing the make-to-stock queue in the supply chain and eBusiness settings

    E-print Network

    Caldentey, René

    2001-01-01

    This thesis presents two applications of the prototypical make-to-stock queue model that are mainly motivated by supply chain management and e-commerce issues. In the first part, we consider the decentralized version of ...

  1. Regenerative Estimation Variants of Response Times in Closed Networks of Queues

    E-print Network

    Katsaros, Panagiotis

    Regenerative Estimation Variants of Response Times in Closed Networks of Queues PANAJOTIS KATSAROS regenerative estimation variants of response times, in multivariate simulations of closed queuing networks. Key-Words: - Queuing networks, Regenerative method, Simulation output analysis, Sequential control

  2. A Dynamical Queue Approach to Intelligent Task Management for Human Operators

    E-print Network

    Frazzoli, Emilio

    Formal methods for task management for human operators are gathering increasing attention to improve efficiency of human-in-the-loop systems. In this paper, we consider a novel dynamical queue approach to intelligent task ...

  3. LIMITS FOR QUEUES AS THE WAITING ROOM GROWS Daniel P. Heyman Ward Whitt

    E-print Network

    Whitt, Ward

    LIMITS FOR QUEUES AS THE WAITING ROOM GROWS by Daniel P. Heyman Ward Whitt Bell Communications Research AT&T Bell Laboratories Red Bank, NJ 07701 Murray Hill, NJ 07974 May 11, 1988 #12;ABSTRACT We study

  4. QUEUES WITH SERVER VACATIONS AND LE VY PROCESSES WITH SECONDARY JUMP INPUT

    E-print Network

    Whitt, Ward

    * and Ward Whitt** November 16, 1989 Revision: June 5, 1990 American Mathematical Society 1980 subject Hill, NJ 07974­ 2070. #12; ABSTRACT Motivated by models of queues with server vacations, we consider

  5. Store operation with conditional push of a tag value to a queue

    DOEpatents

    Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2015-07-28

    According to one embodiment, a method for a store operation with a conditional push of a tag value to a queue is provided. The method includes configuring a queue that is accessible by an application, setting a value at an address in a memory device including a memory and a controller, receiving a request for an operation using the value at the address and performing the operation. The method also includes the controller writing a result of the operation to the address, thus changing the value at the address, the controller determining if the result of the operation meets a condition and the controller pushing a tag value to the queue based on the condition being met, where the tag value in the queue indicates to the application that the condition is met.

  6. Random linear network coding for time-division duplexing: queueing analysis

    E-print Network

    Medard, Muriel

    We study the performance of random linear network coding for time division duplexing channels with Poisson arrivals. We model the system as a bulk-service queue with variable bulk size. A full characterization for random ...

  7. Queueing Syst DOI 10.1007/s11134-011-9216-3

    E-print Network

    Tsimring, Lev S.

    been investigating an alternative approach using dimension reduction results for multiclass queueing for coupled enzymatic processing of multiple protein species. In this application, protein species to reneging. We developed formulas for correlations between the numbers of molecules of different protein

  8. Class-Based Thresholds: Lightweight Active Router-Queue Management for Multimedia Networking

    E-print Network

    Jeffay, Kevin

    Class-Based Thresholds: Lightweight Active Router- Queue Management for Multimedia Networking RIGHTS RESERVED #12;iii ABSTRACT MARK PARRIS: Class-Based Thresholds: Lightweight Active Router- liorate congestion by arriving at an aggregate operating point where the generated load matches

  9. A comparison of queueing, cluster and distributed computing systems

    NASA Technical Reports Server (NTRS)

    Kaplan, Joseph A.; Nelson, Michael L.

    1993-01-01

    Using workstation clusters for distributed computing has become popular with the proliferation of inexpensive, powerful workstations. Workstation clusters offer both a cost effective alternative to batch processing and an easy entry into parallel computing. However, a number of workstations on a network does not constitute a cluster. Cluster management software is necessary to harness the collective computing power. A variety of cluster management and queuing systems are compared: Distributed Queueing Systems (DQS), Condor, Load Leveler, Load Balancer, Load Sharing Facility (LSF - formerly Utopia), Distributed Job Manager (DJM), Computing in Distributed Networked Environments (CODINE), and NQS/Exec. The systems differ in their design philosophy and implementation. Based on published reports on the different systems and conversations with the system's developers and vendors, a comparison of the systems are made on the integral issues of clustered computing.

  10. Stochastic queueing-theory approach to human dynamics

    NASA Astrophysics Data System (ADS)

    Walraevens, Joris; Demoor, Thomas; Maertens, Tom; Bruneel, Herwig

    2012-02-01

    Recently, numerous studies have shown that human dynamics cannot be described accurately by exponential laws. For instance, Barabási [Nature (London)NATUAS0028-083610.1038/nature03459 435, 207 (2005)] demonstrates that waiting times of tasks to be performed by a human are more suitably modeled by power laws. He presumes that these power laws are caused by a priority selection mechanism among the tasks. Priority models are well-developed in queueing theory (e.g., for telecommunication applications), and this paper demonstrates the (quasi-)immediate applicability of such a stochastic priority model to human dynamics. By calculating generating functions and by studying them in their dominant singularity, we prove that nonexponential tails result naturally. Contrary to popular belief, however, these are not necessarily triggered by the priority selection mechanism.

  11. Simultaneous service approach for reducing air passenger queue time

    SciTech Connect

    Chung, C.A.; Sodeinde, T.

    2000-02-01

    Simultaneous service offers service-oriented organizations, such as the air passenger transportation industry, the opportunity to differentiate themselves by providing superior customer service. The concept of simultaneous service is analogous to the concept of simultaneous engineering. However, while simultaneous engineering strives to minimize product development time, simultaneous service strives to minimize customer processing time. Overall customer processing time is reduced by the identification and simultaneous alignment of previously sequentially executed customer service activities. A simultaneous service approach was applied to the international ticketing counter at a major international airport. This involved developing both equipment and operational policy alternatives to the normal sequencing of the ticketing and baggage check-in process. A total of five alternative simultaneous service approaches were investigated. Simulation analysis of these alternatives indicates that a 36% improvement in customer queue and servicing time was possible with this approach.

  12. 40 CFR 85.1404 - Maintenance of records for urban bus operators; submittal of information; right of entry.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...false Maintenance of records for urban bus operators; submittal of information; right...AIR POLLUTION FROM MOBILE SOURCES Urban Bus Rebuild Requirements § 85.1404 Maintenance of records for urban bus operators; submittal of information;...

  13. 78 FR 40268 - Conway's Bus Service, Inc.-Sale Of Certain Assets-Academy Express, L.L.C.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-03

    ...Board [Docket No. MCF 21053] Conway's Bus Service, Inc.--Sale Of Certain Assets...SUMMARY: On June 4, 2013, Conway's Bus Service, Inc. (CBS), and Academy Express...and (5) the trade name, ``Conway's Bus Service.'' According to...

  14. 76 FR 42730 - In the Matter of Certain Univeral Serial Bus (“USB”) Portable Storage Devices, Including USB...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-19

    ...In the Matter of Certain Univeral Serial Bus (``USB'') Portable Storage Devices...importation of certain universal serial bus (``USB'') portable storage devices...importation of certain universal serial bus (``USB'') portable storage...

  15. 25 CFR 39.710 - How does a school calculate annual bus transportation miles for day students?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...false How does a school calculate annual bus transportation miles for day students...710 How does a school calculate annual bus transportation miles for day students? To calculate the total annual bus transportation miles for day...

  16. 1393 Ring Bus at JPL: Description and Status

    NASA Technical Reports Server (NTRS)

    Wysocky, Terry R.

    2007-01-01

    Completed Ring Bus IC V&V Phase - Ring Bus Test Plan Completed for SIM Project - Applicable to Other Projects Implemented a Avionics Bus Based upon the IEEE 1393 Standard - Excellent Starting Point for a General Purpose High-Speed Spacecraft Bus - Designed to Meet SIM Requirements for - Real-time deterministic, distributed systems. - Control system requirements - Fault detection and recovery Other JPL Projects Considering Implementation F'light Software Ring Bus Driver Module Began in 2006, Continues Participating in Standard Revision. Search for Earth-like planets orbiting nearby stars and measure the masses and orbits of the planets it finds. Survey 2000 nearby stars for planetary systems to learn whether our Solar System is unusual, or typical. Make a new catalog of star position 100 times more accurate than current measurements. Learn how our galaxy formed and will evolve by studying the dynamics of its stars. Critically test models of exactly how stars shine, including exotic objects like black holes, neutron stars and white dwarfs.

  17. Contagion processes on urban bus networks in Indian cities

    E-print Network

    Chatterjee, Atanu; Jagannathan, Krishna

    2015-01-01

    Bus transportation is considered as one of the most convenient and cheapest modes of public transportation in Indian cities. Due to their cost-effectiveness and wide reachability, they help a significant portion of the human population in cities to reach their destinations every day. Although from a transportation point of view they have numerous advantages over other modes of public transportation, they also pose a serious threat of contagious diseases spreading throughout the city. The presence of numerous local spatial constraints makes the process and extent of epidemic spreading extremely difficult to predict. Also, majority of the studies have focused on the contagion processes on scale-free network topologies whereas, spatially-constrained real-world networks such as, bus networks exhibit a wide-spectrum of network topology. Therefore, we aim in this study to understand this complex dynamical process of epidemic outbreak and information diffusion on the bus networks for six different Indian cities usin...

  18. American Fuel Cell Bus Project Evaluation. Second Report

    SciTech Connect

    Eudy, Leslie; Post, Matthew

    2015-09-01

    This report presents results of the American Fuel Cell Bus (AFCB) Project, a demonstration of fuel cell electric buses operating in the Coachella Valley area of California. The prototype AFCB was developed as part of the Federal Transit Administration's (FTA's) National Fuel Cell Bus Program. Through the non-profit consortia CALSTART, a team led by SunLine Transit Agency and BAE Systems developed a new fuel cell electric bus for demonstration. SunLine added two more AFCBs to its fleet in 2014 and another in 2015. FTA and the AFCB project team are collaborating with the U.S. Department of Energy (DOE) and DOE's National Renewable Energy Laboratory to evaluate the buses in revenue service. This report summarizes the performance results for the buses through June 2015.

  19. A methodology for identifying potential locations for bus priority treatments in the London Network

    E-print Network

    Machlab, Farah J. (Farah Jacinthe)

    2014-01-01

    Bus priority strategies provide preferential treatment to buses operating in mixed traffic. This thesis aims at developing a methodology for identifying locations for potential bus priority implementation, referred to as ...

  20. 77 FR 71865 - Over-the-Road Bus Accessibility Grant Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-04

    ...Transit Administration Over-the-Road Bus Accessibility Grant Program AGENCY: Federal...appropriations for the Over-the-Road Bus (OTRB) Accessibility Program, authorized...private operators of over-the-road buses to help finance the incremental...

  1. 77 FR 5295 - Over-the-Road Bus Accessibility Program Announcement of Project Selections

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-02

    ...Transit Administration Over-the-Road Bus Accessibility Program Announcement of Project...appropriations for the Over-the-Road Bus (OTRB) Accessibility Program, authorized...private operators of over-the-road buses to help finance the incremental...

  2. 76 FR 17738 - Over-the-Road Bus Accessibility Program Announcement of Project Selections

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-30

    ...Transit Administration Over-the-Road Bus Accessibility Program Announcement of Project...appropriations for the Over-the- Road Bus (OTRB) Accessibility Program, authorized...private operators of over-the-road buses to help finance the incremental...

  3. Quantum Bus of Metal Nanowire with Surface Plasmon Polaritons

    E-print Network

    Guo-Ping Guo; Zhi-Rong Lin; Tao Tu; Hai-Ou Li; Chang-Ling Zou; Xi-Feng Ren; Guang-Can Guo

    2010-04-15

    We develop an architecture for distributed quantum computation using quantum bus of plasmonic circuits and spin qubits in self-assembled quantum dots. Deterministic quantum gates between two distant spin qubits can be reached by using an adiabatic approach in which quantum dots couple with highly detuned plasmon modes in a metallic nanowire. Plasmonic quantum bus offers a robust and scalable platform for quantum optics experiments and the development of on-chip quantum networks composed of various quantum nodes, such as quantum dots, molecules and nanoparticles.

  4. S-100-bus microcomputers aim at high-performance systems

    SciTech Connect

    Warren, C.

    1982-08-18

    The explosion in integrated low-cost desktop computer systems for single-user dedicated applications has a companion trend: a growing interest in high-performance multitasking multiuser systems and in system architecture which lend themselves easily to peripheral- and procesing-power expansion. The mature S-100 (IEEE-696) bus, once the domain of hobby computers, offers a variety of advantages to serve such applications; thus, systems designed around this bus are enjoying a revival. Microcomputers, from a number of manufacturers, which follow this trend are described.

  5. Performance Evaluation of UHF RFID Technologies for Real-Time Bus Recognition in the Taipei Bus Station

    PubMed Central

    Own, Chung-Ming; Lee, Da-Sheng; Wang, Ti-Ho; Wang, De-Jun; Ting, Yu-Lun

    2013-01-01

    Transport stations such as airports, ports, and railways have adopted blocked-type pathway management to process and control travel systems in a one-directional manner. However, this excludes highway transportation where large buses have great variability and mobility; thus, an instant influx of numerous buses increases risks and complicates station management. Focusing on Taipei Bus Station, this study employed RFID technology to develop a system platform integrated with modern information technology that has numerous characteristics. This modern information technology comprised the following systems: ultra-high frequency (UHF) radio-frequency identification (RFID), ultrasound and license number identification, and backstage graphic controls. In conclusion, the system enabled management, bus companies, and passengers to experience the national bus station's new generation technology, which provides diverse information and synchronization functions. Furthermore, this technology reached a new milestone in the energy-saving and efficiency-increasing performance of Taiwan's buses. PMID:23778192

  6. Performance evaluation of UHF RFID technologies for real-time bus recognition in the Taipei Bus Station.

    PubMed

    Own, Chung-Ming; Lee, Da-Sheng; Wang, Ti-Ho; Wang, De-Jun; Ting, Yu-Lun

    2013-01-01

    Transport stations such as airports, ports, and railways have adopted blocked-type pathway management to process and control travel systems in a one-directional manner. However, this excludes highway transportation where large buses have great variability and mobility; thus, an instant influx of numerous buses increases risks and complicates station management. Focusing on Taipei Bus Station, this study employed RFID technology to develop a system platform integrated with modern information technology that has numerous characteristics. This modern information technology comprised the following systems: ultra-high frequency (UHF) radio-frequency identification (RFID), ultrasound and license number identification, and backstage graphic controls. In conclusion, the system enabled management, bus companies, and passengers to experience the national bus station's new generation technology, which provides diverse information and synchronization functions. Furthermore, this technology reached a new milestone in the energy-saving and efficiency-increasing performance of Taiwan's buses. PMID:23778192

  7. Optical bus waveguide metallic hard mold fabrication with opposite 45 micro-mirrors

    E-print Network

    Chen, Ray

    Optical bus waveguide metallic hard mold fabrication with opposite 45º micro-mirrors Xinyuan Doua In this paper, 3-to-3 metallic hard mold for optical bus waveguide with opposite 45º micro-mirrors was successfully fabricated using electroplating method. The optical bus waveguide pre-mold with 45º surfaces

  8. 49 CFR 571.221 - Standard No. 221; School bus body joint strength.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., determine its tensile strength by cutting a sheet specimen from outside the joint region of the bus body in... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 221; School bus body joint strength... STANDARDS Federal Motor Vehicle Safety Standards § 571.221 Standard No. 221; School bus body joint...

  9. 49 CFR 571.221 - Standard No. 221; School bus body joint strength.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... specimen from outside the joint region of the bus body in accordance with Figure 1 of ASTM E8-89, and by... 49 Transportation 6 2013-10-01 2013-10-01 false Standard No. 221; School bus body joint strength... STANDARDS Federal Motor Vehicle Safety Standards § 571.221 Standard No. 221; School bus body joint...

  10. 49 CFR 571.221 - Standard No. 221; School bus body joint strength.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... specimen from outside the joint region of the bus body in accordance with Figure 1 of ASTM E8-89, and by... 49 Transportation 6 2012-10-01 2012-10-01 false Standard No. 221; School bus body joint strength... STANDARDS Federal Motor Vehicle Safety Standards § 571.221 Standard No. 221; School bus body joint...

  11. 49 CFR 571.221 - Standard No. 221; School bus body joint strength.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... specimen from outside the joint region of the bus body in accordance with Figure 1 of ASTM E8-89, and by... 49 Transportation 6 2014-10-01 2014-10-01 false Standard No. 221; School bus body joint strength... STANDARDS Federal Motor Vehicle Safety Standards § 571.221 Standard No. 221; School bus body joint...

  12. 49 CFR 571.221 - Standard No. 221; School bus body joint strength.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., determine its tensile strength by cutting a sheet specimen from outside the joint region of the bus body in... 49 Transportation 6 2011-10-01 2011-10-01 false Standard No. 221; School bus body joint strength... STANDARDS Federal Motor Vehicle Safety Standards § 571.221 Standard No. 221; School bus body joint...

  13. Beware of high stresses in ``A`` frame supported two-level bus structures

    SciTech Connect

    Thaik, A.

    1995-10-01

    Rigid-bus structures in many low profile, high voltage transmission substations consist of two-level bus assemblies of tubular conductors with one bus assembly supporting the other bus assembly with rigid tubular ``A`` frames at the crossover points. The lower-level bus is normally supported by a single porcelain post insulator under the ``A`` frame. Rigid ``A`` frames not only support the upper-level bus assembly, but also make the electrical connections between the two buses. This paper addresses the stress problem in the lower-level bus of the two-level bus structure. It presents the results of the structural analysis of a sample two-level bus structure using a simple structural method based on the Three Moment Theorem and equilibrium equations. A spreadsheet template is used to perform the mathematical calculations. The spreadsheet first calculates the maximum allowable bus span length in accordance with the IEEE Standard 605 and then determines the internal stress on the upper and lower-level bus conductors in the two-level rigid bus structures.

  14. School Bus Rider Safety Education Modules for Use with Drills on School Buses.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Div. of Physical Education, Fitness, Health, Nutrition and Safety Services.

    Developed for teachers and members of the pupil transportation staff who conduct school bus drills, these 10 lesson outlines are intended for classroom instruction on school bus safety. Lessons may be adapted to fit the grade level, intelligence, and special needs of students. Topics covered are: preparing to ride the bus, boarding and proceeding…

  15. 49 CFR 383.123 - Requirements for a school bus endorsement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Requirements for a school bus endorsement. 383.123... Requirements for a school bus endorsement. (a) An applicant for a school bus endorsement must satisfy the... devices required for school buses by State or Federal law or regulation. (ii) Emergency exits...

  16. 49 CFR 571.220 - Standard No. 220; School bus rollover protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 220; School bus rollover protection... STANDARDS Federal Motor Vehicle Safety Standards § 571.220 Standard No. 220; School bus rollover protection. S1. Scope. This standard establishes performance requirements for school bus rollover protection....

  17. The Role of the Coroner in School Bus Accident Prevention: Some Recommendations.

    ERIC Educational Resources Information Center

    Fox, Michael

    1995-01-01

    Following the deaths of two elementary school students in bus-related accidents in 1992, the Coroner of Quebec held extensive hearings investigating school bus safety and accident prevention. A subsequent report addressed responsibilities of government and school board officials to correct deficiencies in school bus services and provided…

  18. 75 FR 66686 - Federal Motor Vehicle Safety Standards; Seat Belt Assembly Anchorages, School Bus Passenger...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-29

    ... the strength of the seating system and seat belt anchorages.\\2\\ \\3\\ \\1\\ ``School bus'' is defined in... that it only builds large school buses ``and could specifically develop a seating system that... small school bus seating systems (tests using a small school bus crash pulse with restrained...

  19. Instructor's Behind-the-Wheel Guide for California's Bus Driver's Training Course.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento.

    Intended to help produce safe, competent California school bus drivers, this document contains instructor's materials for a bus driver education course with eight sequential skill levels, including a final appraisal. The first section contains the curriculum's purpose and objectives, the California standards for a state-certified bus driver…

  20. Using the Tools in TRADE III: A Controller for a Compact Dynamic Bus Station

    E-print Network

    Wieringa, Roel

    Using the Tools in TRADE III: A Controller for a Compact Dynamic Bus Station R.J.Wieringa1 July 21 of a compact dynamic bus station, which is a bus station in which busses are dynamically allocated to platforms. Dynamic allocation can save space in comparison to static allocation, because in dynamic allocation

  1. SunLine Leads the Way in Demonstrating Hydrogen-Fueled Bus Technologies (Brochure)

    SciTech Connect

    Not Available

    2011-01-01

    This brochure describes SunLine Transit Agency's newest advanced technology fuel cell electric bus. SunLine is collaborating with the U.S. Department of Energy's Fuel Cell Technologies Program to evaluate the bus in revenue service. This bus represents the sixth generation of hydrogen-fueled buses that the agency has operated since 2000.

  2. Improving Elementary School Students' Bus Behavior through a Driver and Student Training Program.

    ERIC Educational Resources Information Center

    Richardson, Donald M.

    This practicum report analyzes a driver and student training program developed at an elementary school to improve students' bus conduct. Seventy percent of students require transportation by school bus. Except for chronic bus misconduct, discipline has not been a school concern. It was hypothesized that the lack of a comprehensive program…

  3. Bus Operations for Pupil Transportation. "Chrome-Yellow and Red Lights."

    ERIC Educational Resources Information Center

    Rannels, Morris W.

    This paper is based on a committee report of the last National School Bus Conference on "Minimum Standards for School Buses." Standards for school bus operations are included for (1) administrators, (2) supervisors, (3) school bus drivers, (4) student passengers, and (5) maintenance and service personnel. The report deals also with procedures for…

  4. Computer-Based Video Instruction to Teach Students with Intellectual Disabilities to Use Public Bus Transportation

    ERIC Educational Resources Information Center

    Mechling, Linda; O'Brien, Eileen

    2010-01-01

    This study investigated the effectiveness of computer-based video instruction (CBVI) to teach three young adults with moderate intellectual disabilities to push a "request to stop bus signal" and exit a city bus in response to target landmarks. A multiple probe design across three students and one bus route was used to evaluate effectiveness of…

  5. 46 CFR 112.05-3 - Main-emergency bus-tie.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Main-emergency bus-tie. 112.05-3 Section 112.05-3 Shipping...SYSTEMS General § 112.05-3 Main-emergency bus-tie. Each bus-tie between a main switchboard and an emergency...

  6. 75 FR 71792 - National Express Corporation-Control Exemption-Vogel Bus Company, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-24

    ...Corporation--Control Exemption--Vogel Bus Company, Inc. AGENCY: Surface Transportation...49 CFR 1182 to acquire control of Vogel Bus Company, Inc. (Vogel), a motor passenger...school children, in New Jersey. School bus transportation is not subject to Board...

  7. Riding the School Bus: A Comparison of the Rural and Suburban Experience in Five States.

    ERIC Educational Resources Information Center

    Howley, Craig B.; Howley, Aimee A.; Shamblen, Steven

    2001-01-01

    A study comparing rural and suburban school bus rides surveyed 1,194 elementary principals in five states. Rural elementary schools were more likely than suburban schools to have bus rides of 30 minutes of more, attendance areas greater than 10 square miles, rough rides, and older students on the bus with elementary students. (Contains 41…

  8. WPI-CS-TR-06-20 October 2006 Measuring the Queue Sizes of IEEE 802.11 Wireless Access Points

    E-print Network

    Kinicki, Robert E.

    degraded Quality of Service when large AP queues become saturated by other concurrent flows. HoweverWPI-CS-TR-06-20 October 2006 Measuring the Queue Sizes of IEEE 802.11 Wireless Access Points, Massachusetts 01609-2280 #12;Measuring the Queue Sizes of IEEE 802.11 Wireless Access Points Feng Li, Rui Lu

  9. Issues in School Bus Safety: Real or Red Herring?

    ERIC Educational Resources Information Center

    Leeds, Robin L.

    1999-01-01

    In many states, the greatest threat to safe student transportation is elimination of the school transportation program. Using public transit buses, large vans, smaller vehicles, or specialized equipment can cause major-issue headaches. False issues include controversies over seat belts, bus design, and optional "bells and whistles." (10…

  10. Training Needs Analysis for Bus Depot Managers at GSRTC

    ERIC Educational Resources Information Center

    Shah, Hardik; Gopal, Raj

    2012-01-01

    Purpose: With rapid industrialization and population growth in the urban and rural areas in India, the demand for public transport has risen sharply. In the fast changing scenario in the public transit sector, the role of a bus depot manager (DM) has also undergone substantial transformation. This paper aims to identify and gauge the…

  11. Verifying a Virtual Component Interfacebased PCI Bus Wrapper

    E-print Network

    Component Interface (VCI) Standard. This paper reports recent experiences in formally verifying a few properties of a VCI­compliant PCI 2.1 bus wrapper model in the formal verification tool, FormalCheck. Though Component Interface (VCI) Standard [Gro00]. The VCI is designed to allow compliant virtual com­ ponents

  12. Verifying a Virtual Component Interface-based PCI Bus Wrapper

    E-print Network

    Component Interface (VCI) Standard. This paper reports recent experiences in formally verifying a few properties of a VCI-compliant PCI 2.1 bus wrapper model in the formal verification tool, FormalCheck. Though Component Interface (VCI) Standard [Gro00]. The VCI is designed to allow compliant virtual com- ponents

  13. High-Tech School Bus Teaches Students on the Road

    ERIC Educational Resources Information Center

    Katims, Lauren

    2011-01-01

    Last year, kindergarten through high school students in the rural Hector, Arkansas, School District barely had the technology resources that keep kids interested in math and science. This year, they potentially have the most advanced resources in the country--before they even step into the classroom. One school bus in Arkansas' Pope County has…

  14. On-Board Hydrogen Storage for a City Transit Bus

    SciTech Connect

    Heung, L.K.

    1998-03-01

    An electric bus was modified to use hydrogen fuel for demonstration in the city of Augusta, Georgia, USA. The hydrogen fuel is stored in a solid form using an on-board metal hydride storage system. The storage system performs better than expected.

  15. Implementation of a Walking School Bus: Lessons Learned

    ERIC Educational Resources Information Center

    Kong, Alberta S.; Sussman, Andrew L.; Negrete, Sylvia; Patterson, Nissa; Mittleman, Rachel; Hough, Richard

    2009-01-01

    Background: Obesity is rapidly becoming the most common chronic medical condition affecting children. To address this crisis, an Albuquerque, New Mexico, elementary school partnered with University of New Mexico researchers and conducted a Walking School Bus (WSB). The purpose of this article is to examine the feasibility of implementing a WSB.…

  16. 38. Photocopy of photograph (Pentran file), photographer unknown. Bus garage ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. Photocopy of photograph (Pentran file), photographer unknown. Bus garage to left now demolished. Trolley car drivers, maintenance personnel and management staff in 1915. VIEW SOUTH - Newport News & Old Point Railway & Electric Company, Trolley Barn & Administration Building, 3400 Victoria Boulevard, Hampton, Hampton, VA

  17. Course Guide for School Bus Driver Training in Texas. Revised.

    ERIC Educational Resources Information Center

    Texas State Dept. of Public Safety, Austin.

    The safe and effective transportation of pupils to and from schol is an integral part of a sound educational program. This course guide is a study and reference tool for use in a training course designed to promote the competency of school bus drivers throughout the State of Texas. Unit 1 of the guide provides an overview of the transportation…

  18. School Bus Crash Rates on Routine and Nonroutine Routes

    ERIC Educational Resources Information Center

    O'Neal, Elizabeth; Ramirez, Marizen; Hamann, Cara; Young, Tracy; Stahlhut, Mary; Peek-Asa, Corinne

    2014-01-01

    Background: Although prior research has established that school buses are a safe form of transportation, crashes can produce catastrophic consequences. School buses have 2 types of routes: predictable, routine routes that take children to and from school and less predictable, nonroutine routes for school events. No studies have examined school bus

  19. Manual of First Aid Practices for School Bus Drivers.

    ERIC Educational Resources Information Center

    Nesbitt, William R.

    This manual is intended to assist local school authorities in California in providing the required course in instruction in first aid practices for school bus drivers. While it deals with basic principles of handling serious medical emergencies, major emphasis is on minor injuries or illnesses that are most likely to occur while students are…

  20. Augmented thermal bus wih multiple thermoelectric devices individually controlled

    NASA Technical Reports Server (NTRS)

    Schrage, Dean S. (Inventor)

    1994-01-01

    The present invention is directed to an augmented thermal bus. In the present design a plurality of thermo-electric heat pumps are used to couple a source plate to a sink plate. Each heat pump is individually controlled by a model based controller. The controller coordinates the heat pumps to maintain isothermality in the source.

  1. Communication Strategies for Shared-Bus Embedded Multiprocessors

    E-print Network

    Bhattacharyya, Shuvra S.

    1 Communication Strategies for Shared-Bus Embedded Multiprocessors Neal K. Bambha US Army Research of efficiently order- ing interprocessor communication operations in both statically and dynamically processing applications, the throughput of the system is significantly affected by communication costs. We

  2. The Diagnostic and Predictive Validity of "The Renfrew Bus Story"

    ERIC Educational Resources Information Center

    Pankratz, Mary E.; Plante, Elena; Vance, Rebecca; Insalaco, Deborah M.

    2007-01-01

    Purpose: Two studies are presented providing evidence indicating the diagnostic and predictive validity of the American version of "The Renfrew Bus Story" (J. Cowley & C. Glasgow, 1994). Method: Thirty-two children with specific language impairment (SLI) and 32 children with typical language development participated in the first study to determine…

  3. Improving School Bus Safety. Transportation Research Board Special Report 222.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Transportation Research Board.

    While school buses transport more passengers per trip, the rate of occupant fatalities per mile driven for school buses is one-quarter that for passenger cars. Nevertheless, the public expects school districts and other school bus operators to take all reasonable precautions to protect children as they travel to and from school. Although a variety…

  4. Schools, Computers Solve 'Mind Boggling' Bus Transport Problem

    ERIC Educational Resources Information Center

    Griggs, Norman; Morgan, Larry

    1975-01-01

    Describes a districtwide effort to select and implement a computerized system that could compile and maintain student census data, in addition to redesigning the district's school bus routes to better accommodate a growing student population without increasing the number of buses in service. (JG)

  5. BEAM: Bus Encoding Based on Instruction-Set-Aware Memories

    E-print Network

    Pedram, Massoud

    % 80% 100% vpr parser equake vortex gcc art Transitions Costs after Applying Offset-XOR-SM seqbtrans Large external capacitance: Cext Internal capacitance: Cint Cext>>Cint Bus Power Minimization Physical Sourceword (Address) #12;3 Transition Cost Transition cost of an instruction or data address is defined as

  6. What's Happening on the School Bus Performance Front?

    ERIC Educational Resources Information Center

    Combs, Hanford L.

    The most urgent order of business in the national scene is to complete the development of a series of new performance tests for school bus bodies and chassis to establish a benchmark for safe construction that can be verified by independent testing agencies. Such performance tests should incorporate the new Federal Joint Strength Efficiency…

  7. Bus Talk: A Preliminary Analysis of Children's Decontextualized Talk

    ERIC Educational Resources Information Center

    Marvin, Christine A.; Cline, Keely D.

    2010-01-01

    Decontextualized conversational talk has been recognized as an important foundation for young children's early literacy and academic success. In this study, the authors explore the tape-recorded conversations of 15 typically developing preschool-age children. The children's talk was recorded as they traveled home from preschool on a school bus

  8. Real life testing of a Hybrid PEM Fuel Cell Bus

    NASA Astrophysics Data System (ADS)

    Folkesson, Anders; Andersson, Christian; Alvfors, Per; Alaküla, Mats; Overgaard, Lars

    Fuel cells produce low quantities of local emissions, if any, and are therefore one of the most promising alternatives to internal combustion engines as the main power source in future vehicles. It is likely that urban buses will be among the first commercial applications for fuel cells in vehicles. This is due to the fact that urban buses are highly visible for the public, they contribute significantly to air pollution in urban areas, they have small limitations in weight and volume and fuelling is handled via a centralised infrastructure. Results and experiences from real life measurements of energy flows in a Scania Hybrid PEM Fuel Cell Concept Bus are presented in this paper. The tests consist of measurements during several standard duty cycles. The efficiency of the fuel cell system and of the complete vehicle are presented and discussed. The net efficiency of the fuel cell system was approximately 40% and the fuel consumption of the concept bus is between 42 and 48% lower compared to a standard Scania bus. Energy recovery by regenerative braking saves up 28% energy. Bus subsystems such as the pneumatic system for door opening, suspension and brakes, the hydraulic power steering, the 24 V grid, the water pump and the cooling fans consume approximately 7% of the energy in the fuel input or 17% of the net power output from the fuel cell system. The bus was built by a number of companies in a project partly financed by the European Commission's Joule programme. The comprehensive testing is partly financed by the Swedish programme "Den Gröna Bilen" (The Green Car). A 50 kW el fuel cell system is the power source and a high voltage battery pack works as an energy buffer and power booster. The fuel, compressed hydrogen, is stored in two high-pressure stainless steel vessels mounted on the roof of the bus. The bus has a series hybrid electric driveline with wheel hub motors with a maximum power of 100 kW. Hybrid Fuel Cell Buses have a big potential, but there are still many issues to consider prior to full-scale commercialisation of the technology. These are related to durability, lifetime, costs, vehicle and system optimisation and subsystem design. A very important factor is to implement an automotive design policy in the design and construction of all components, both in the propulsion system as well as in the subsystems.

  9. Unreliable bulk retrial queues with delayed repairs and modified vacation policy

    NASA Astrophysics Data System (ADS)

    Jain, Madhu; Bhagat, Amita

    2014-06-01

    The present investigation deals with the bulk arrival M/G/1 retrial queue with impatient customers and modified vacation policy. The incoming customers join the virtual pool of customers called orbit if they find the server being busy, on vacation or in broken down state otherwise the service of the customer at the head of the batch is started by the server. The service is provided in k essential phases to all the customers by the single server which may breakdown while rendering service to the customers. The broken down server is sent to a repair facility wherein the repair is performed in d compulsory phases. As soon as the orbit becomes empty, the server goes for vacation and takes at most J vacations until at least one customer is noticed. The incoming customers are impatient and may renege on seeing a long queue of the customers for the service. The probability generating functions and queue length for the number of customers in the orbit and queue have been obtained using supplementary variable technique. Various system characteristics viz. average number of customers in the queue and the orbit, long run probabilities of the system states, etc. are obtained. Furthermore, numerical simulation has been carried out to study the sensitivity of various parameters on the system performance measures by taking an illustration.

  10. Method and apparatus for efficiently tracking queue entries relative to a timestamp

    SciTech Connect

    Blumrich, Matthias A.; Chen, Dong; Gara, Alan G.; Giampapa, Mark E.; Heidelberger, Philip; Ohmacht, Martin; Salapura, Velentina; Vranas, Pavlos

    2014-06-17

    An apparatus and method for tracking coherence event signals transmitted in a multiprocessor system. The apparatus comprises a coherence logic unit, each unit having a plurality of queue structures with each queue structure associated with a respective sender of event signals transmitted in the system. A timing circuit associated with a queue structure controls enqueuing and dequeuing of received coherence event signals, and, a counter tracks a number of coherence event signals remaining enqueued in the queue structure and dequeued since receipt of a timestamp signal. A counter mechanism generates an output signal indicating that all of the coherence event signals present in the queue structure at the time of receipt of the timestamp signal have been dequeued. In one embodiment, the timestamp signal is asserted at the start of a memory synchronization operation and, the output signal indicates that all coherence events present when the timestamp signal was asserted have completed. This signal can then be used as part of the completion condition for the memory synchronization operation.

  11. 2838 IEEE TRANSACTIONS ON INFORMATION THEORY, VOL. 52, NO. 6, JUNE 2006 Constructions of Optical FIFO Queues

    E-print Network

    Lee, Duan-Shin

    Abstract--Discrete-time queues are infinite dimensional switches in time. Ever since Shannon published his-stage construction of optical FIFO queues via switched delay lines (SDLs). Via recursively expanding the three as infinite dimensional switches in time. To illustrate this, in Fig. 1 we show a typical sample path

  12. System Optimum in M/G/c/c Queues Cruz, van Woensel, Smith, & Lieckens On the System Optimum of

    E-print Network

    Cruz, Frederico

    of Traffic Assignment in M/G/c/c State-dependent Queueing Networks F. R. B. Cruz T. van Woensel J. Mac that the proposed approach is efficient. Keywords -- System Optimum; traffic assignment; queue- ing networks Equilib- rium (UE) is an important classical traffic assignment model approach (Sheffi, 1985), which even

  13. Waiting time analysis of BMAP vacation queue and its application to IEEE 802.16e sleep mode

    E-print Network

    Telek, Miklós

    Waiting time analysis of BMAP vacation queue and its application to IEEE 802.16e sleep mode Zsolt-time BMAP/G/1 queue with multiple vacations and with its application to IEEE 802.16e sleep mode. The lengths the application of this vacation model to IEEE 802.16e sleep mode mechanism is demonstrated. Categories

  14. An intelligent fiberoptic data bus for fly-by-light applications

    NASA Astrophysics Data System (ADS)

    Manoharan, L. C.; Muthuvel, S.

    An active fiberoptic data bus compatible with MIL-STD-1553B, which could be used for fly-by-light, stores management, AEW etc., on an aircraft has been developed. The data bus is considered intelligent because it can automatically sense which station is in the transmit mode and control the active interface accordingly, so that smooth flow of data takes place on the bus. The tests carried out on the bus including those on the Jaguar Avionics Rig to check its validity are also described. As no software is involved in the operation of the bus, this could be used on any aircraft having its own software.

  15. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: First Results Report

    SciTech Connect

    Eudy, L.; Chandler, K.

    2011-03-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. This report provides the early data results and implementation experience of the AT fuel cell bus since it was placed in service.

  16. Development of the bus joint for the ITER Central Solenoid

    SciTech Connect

    Martovetsky, Nicolai N; Irick, David Kim; Kenney, Steven J

    2013-01-01

    The terminations of the Central Solenoid (CS) modules are connected to the bus extensions by joints located outside the CS in the gap between the CS and Torodial Field (TF) assemblies. These joints have very strict space limitations. Low resistance is a common requirement for all ITER joints. In addition, the CS bus joints will experience and must be designed to withstand significant variation in the magnetic field of several tenths of a Tesla per second during initiation of plasma. The joint resistance is specified to be less than 4 nOhm. The joints also have to be soldered in the field and designed with the possibility to be installed and dismantled in order to allow cold testing in the cold test facility. We have developed coaxial joints that meet these requirements and have demonstrated the feasibility to fabricate and assemble them in the vertical configuration. We introduced a coupling cylinder with superconducting strands soldered to the surface of the cable that can be installed in the ITER assembly hall and at the Cold Test Facility. This cylinder serves as a transition area between the CS module and the bus extension. We made two racetrack samples and tested four bus joints in our Joint Test Apparatus. Resistance of the bus joints was measured by a decay method and by a microvoltmeter; the value of the current was measured by the Hall probes. This measurement method was verified in the previous tests. The resistance of the joints varied insignificantly from 1.5 to 2 nOhm. One of the challenges associated with a soldered joint is the inability to use corrosive chemicals that are difficult to clean. This paper describes our development work on cable preparation, chrome removal, compaction, soldering, and final assembly and presents the test results.

  17. Weighted fair queueing scheduling for World Wide Web proxy servers

    NASA Astrophysics Data System (ADS)

    El Abdouni Khayari, Rachid; Sadre, Ramin; Haverkort, Boudewijn R.; Zoschke, Norman

    2002-07-01

    Current world-wide web servers as well as proxy servers rely for their scheduling on services provided by the underlying operating system. In practice, this means that some form of first-come-first-served (FCFS) scheduling is utilised. Although FCFS is a reasonable scheduling strategy for job sequences that do not show much variance, in the world-wide web (WWW), however, it has been shown that the typical object sizes requested do exhibit heavy tails. This means that the probability to observe very long jobs (very large objects) is much higher than typically predicted using an exponential model. Under these circumstances, job scheduling on the basis of shortest-job first (SJF) has been shown to perform much better, in fact, to minimise the total average waiting time, simply by avoiding situations in which short jobs have to wait for very long one. However, SJF has as disadvantage that long jobs might suffer from starvation. In order to avoid the problems of both FCFS and SJF we present in this paper a new scheduling algorithm called class-based interleaving weighted fair queueing (CI-WFQ). This algorithm uses the specific characteristics of the job stream being served, that is, the distribution of the sizes of the objects being requested, to set its parameters such that good mean reponse times are obtained and starvation does not occur. In the paper, the new scheduling approach is introduced and compared, using trace-driven simulations, with existing scheduling approaches.

  18. Preemptive queueing system with randomized push-out mechanism

    NASA Astrophysics Data System (ADS)

    Muliukha, Vladimir; Ilyashenko, Alexander; Zayats, Oleg; Zaborovsky, Vladimir

    2015-04-01

    In this article considered a queueing theory model with limited buffer size, one service channel, and two incoming flows. In this model one of the flows has a power to preempt other tasks. We call it a high-priority flow. Another one is low-priority. This priority mechanism is realized in a two different ways. The first one is a preemptive priority, which allows high-priority packets to interrupt low-priority packets in service channel and push them out. The second one is a randomized push-out mechanism with probability ?, which allows us to choose what type of packets should be pushed out of the system when it is full. In this article we provide an algorithm for computing statistical characteristics of the model for all values of push-out probability ?. We have used generating functions method to simplify the system of linear equations. This method allows us to reduce the order of linear equations system from k(k + 1)/2 to (k + 1). As the result we have got two effects in this model. The first one is a linear behavior of loss probabilities in the model with low overload. The second one is a "closing" of a system for low-priority packets with high overload.

  19. Queueing theoretical analysis of foreign currency exchange rates

    E-print Network

    Inoue, J; Inoue, Jun-ichi; Sazuka, Naoya

    2006-01-01

    We propose a useful approach to investigate statistical properties of foreign currency exchange rates. Our approach is based on queueing theory, especially, the so-called renewal-reward theorem. For first passage processes of the Sony bank USD/JPY exchange rate, we evaluate the average waiting time which is defined as the average time for customers to wait until the next rate change from any time point when they want to check the rate, for example, when they login to their computer systems. We find that the assumption of exponential distribution on the first passage process should be rejected and a Weibull distribution seems to be more suitable to explain the stochastic process of the Sony bank rate. Our approach also enables us to evaluate the expected reward for customers, namely, one can predict how long customers wait and how much reward they obtain by the next price change after they login to the computer systems. We check the validity by comparing our prediction with empirical data analysis.

  20. Queueing models of picture archiving and communication systems

    NASA Astrophysics Data System (ADS)

    Khanmoradi, Hassan; Nilsson, Arne A.

    1990-08-01

    At present the management of radiological information is done manually in most hospitals. Images from the digital modalities (e.g. Computer- tomography scanners, X-ray machines) are converted into films and stored in a room. These films are then distributed manually and interpretation is done by reading the films through light boxes. With the advances in semiconductor technology and digital processing techniques it is now possible to automate these operations by using a digital system for archiving and communication of images. A Picture Archiving and Communication System (PACS), is a digital system for acquiring, storing, moving and displaying picture or image information .These systems are highly dependent on the new technology for mass storage of data on optical disks. In the medical environment, the ultimate goal of using digital images and PACS is tohave a radiology department without filmjackets 2,3 A typical PACS consists of a database of medical images, display stations, acquisition systems and the communications medium. There are two possible architectures for PACS, one is the distributed PACS where all the modules are linked together through a high speed communication medium, and the other is a centralized PACS where the acquisition nodes and the display stations are part of the system which comprises the image database 4. In this paper we present analytical queueing models of distributed PACS used in the medical environments. These models are for the image database, the picture viewing stations, and the communication channels.

  1. Determination of an Optimal Commercial Data Bus Architecture for a Flight Data System

    NASA Technical Reports Server (NTRS)

    Crawford, Kevin; Johnson, Martin; Humphries, Rick (Technical Monitor)

    2001-01-01

    NASA/Marshall Space Flight Center (MSFC) is continually looking for methods to reduce cost and schedule while keeping the quality of work high. MSFC is NASA's lead center for space transportation and microgravity research. When supporting NASA's programs several decisions concerning the avionics system must be made. Usually many trade studies must be conducted to determine the best ways to meet the customer's requirements. When deciding the flight data system, one of the first trade studies normally conducted is the determination of the data bus architecture. The schedule, cost, reliability, and environments are some of the factors that are reviewed in the determination of the data bus architecture. Based on the studies, the data bus architecture could result in a proprietary data bus or a commercial data bus. The cost factor usually removes the proprietary data bus from consideration. The commercial data bus's range from Versa Module Eurocard (VME) to Compact PCI to STD 32 to PC 104. If cost, schedule and size are prime factors, VME is usually not considered. If the prime factors are cost, schedule, and size then Compact PCI, STD 32 and PC104 are the choices for the data bus architecture. MSFC's center director has funded a study from his discretionary fund to determine an optimal low cost commercial data bus architecture. The goal of the study is to functionally and environmentally test Compact PCI, STD 32 and PC 104 data bus architectures. This paper will summarize the results of the data bus architecture study.

  2. Design of a CAN bus interface for photoelectric encoder in the spaceflight camera

    NASA Astrophysics Data System (ADS)

    Sun, Ying; Wan, Qiu-hua; She, Rong-hong; Zhao, Chang-hai; Jiang, Yong

    2009-05-01

    In order to make photoelectric encoder usable in a spaceflight camera which adopts CAN bus as the communication method, CAN bus interface of the photoelectric encoder is designed in this paper. CAN bus interface hardware circuit of photoelectric encoder consists of CAN bus controller SJA 1000, CAN bus transceiver TJA1050 and singlechip. CAN bus interface controlling software program is completed in C language. A ten-meter shield twisted pair line is used as the transmission medium in the spaceflight camera, and speed rate is 600kbps.The experiments show that: the photoelectric encoder with CAN bus interface which has the advantages of more reliability, real-time, transfer rate and transfer distance overcomes communication line's shortcomings of classical photoelectric encoder system. The system works well in automatic measuring and controlling system.

  3. 40 CFR 85.1404 - Maintenance of records for urban bus operators; submittal of information; right of entry.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Maintenance of records for urban bus... SOURCES Urban Bus Rebuild Requirements § 85.1404 Maintenance of records for urban bus operators; submittal of information; right of entry. (a) The operator of any urban bus for which this subpart...

  4. 40 CFR 85.1404 - Maintenance of records for urban bus operators; submittal of information; right of entry.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Maintenance of records for urban bus... SOURCES Urban Bus Rebuild Requirements § 85.1404 Maintenance of records for urban bus operators; submittal of information; right of entry. (a) The operator of any urban bus for which this subpart...

  5. Development of a composite line source emission model for traffic interrupted microenvironments and its application in particle number emissions at a bus station

    NASA Astrophysics Data System (ADS)

    Wang, Lina; Jayaratne, Rohan; Heuff, Darlene; Morawska, Lidia

    A composite line source emission (CLSE) model was developed to specifically quantify exposure levels and describe the spatial variability of vehicle emissions in traffic interrupted microenvironments. This model took into account the complexity of vehicle movements in the queue, as well as different emission rates relevant to various driving conditions (cruise, decelerate, idle and accelerate), and it utilised multi-representative segments to capture the accurate emission distribution for real vehicle flow. Hence, this model was able to quickly quantify the time spent in each segment within the considered zone, as well as the composition and position of the requisite segments based on the vehicle fleet information, which not only helped to quantify the enhanced emissions at critical locations, but it also helped to define the emission source distribution of the disrupted steady flow for further dispersion modelling. The model then was applied to estimate particle number emissions at a bi-directional bus station used by diesel and compressed natural gas fuelled buses. It was found that the acceleration distance was of critical importance when estimating particle number emission, since the highest emissions occurred in sections where most of the buses were accelerating and no significant increases were observed at locations where they idled. It was also shown that emissions at the front end of the platform were 43 times greater than at the rear of the platform. Although the CLSE model is intended to be applied in traffic management and transport analysis systems for the evaluation of exposure, as well as the simulation of vehicle emissions in traffic interrupted microenvironments, the bus station model can also be used for the input of initial source definitions in future dispersion models.

  6. Middleware for Processing Message Queues with Elasticity Support and Sequential Integrity of Asynchronous Message Processing

    NASA Astrophysics Data System (ADS)

    Henrique Teixeira, Eduardo; Patrícia Favacho de Araújo, Aletéia

    2015-10-01

    Elasticity in computing refers to dynamically adjusting the amount of allocated resources to process a distributed application. In order to achieve this, mechanisms are needed to avoid the phenomenon of the elasticity threshold detection moving constantly up or down. The existing work fails to deliver sequential integrity of asynchronous messages processing and the asymmetries of data distribution to achieve parallel consumption. This paper fills this gaps and proposes a middleware solution to dynamically analyze the flow of message queue, and a mechanism to increase the parallelized consumption based on the output behavior. An architecture for IOD (Increase On Demand) middleware is presented, with support for the increase and decrease of thread's to cope with the growth of message queues, using the technique of limit-based heuristics over a given period of time and grouping messages into sub-queues based on classification criteria.

  7. A GA-based PID active queue management control design for TCP/IP networks

    NASA Astrophysics Data System (ADS)

    Kuo, H.-H.; Chen, C.-K.; Yan, J.-J.; Liao, T.-L.

    2008-02-01

    In this paper, a genetic algorithm-based (GA-based) proportional-integral-derivative (PID) controller as an active queue manager for Internet routers is proposed to reduce packet loss and improve network utilization in TCP/IP networks. Based on the window-based nonlinear dynamics, the TCP network was modeled as a time-delayed system with a saturated input due to the limitations of packet-dropping probability and the effects of propagation delays in TCP networks. An improved genetic algorithm is employed to derive optimal or near optimal PID control gains such that a performance index of integrated-absolute error (IAE) in terms of the error between the router queue length and the desired queue length is minimized. The performance of the proposed control scheme was evaluated in various network scenarios via a series of numerical simulations. The simulation results confirm that the proposed scheme outperforms other AQM schemes.

  8. The M/G/1 retrial queue: New descriptors of the customer's behavior

    NASA Astrophysics Data System (ADS)

    Amador, J.; Artalejo, J. R.

    2009-01-01

    We consider queuing systems where customers are not allowed to queue; instead of that they make repeated attempts, or retrials, in order to enter service after some time. The performance of telephone systems and communication networks modelled as retrial queues differs from standard waiting lines because typically the retrial group is an invisible queue which cannot be observed. As a result, the original flow of primary arrivals and the flow of repeated attempts become undistinguished. Our aim in this paper is to consider some aspects of this problem. Thus, we focus on the main retrial model of M/G/1 type and investigate the distribution of the successful and blocked events made by the primary customers and the retrial customers.

  9. Fast concurrent array-based stacks, queues and deques using fetch-and-increment-bounded, fetch-and-decrement-bounded and store-on-twin synchronization primitives

    DOEpatents

    Chen, Dong; Gara, Alana; Heidelberger, Philip; Kumar, Sameer; Ohmacht, Martin; Steinmacher-Burow, Burkhard; Wisniewski, Robert

    2014-09-16

    Implementation primitives for concurrent array-based stacks, queues, double-ended queues (deques) and wrapped deques are provided. In one aspect, each element of the stack, queue, deque or wrapped deque data structure has its own ticket lock, allowing multiple threads to concurrently use multiple elements of the data structure and thus achieving high performance. In another aspect, new synchronization primitives FetchAndIncrementBounded (Counter, Bound) and FetchAndDecrementBounded (Counter, Bound) are implemented. These primitives can be implemented in hardware and thus promise a very fast throughput for queues, stacks and double-ended queues.

  10. A Queue Simulation Tool for a High Performance Scientific Computing Center

    NASA Technical Reports Server (NTRS)

    Spear, Carrie; McGalliard, James

    2007-01-01

    The NASA Center for Computational Sciences (NCCS) at the Goddard Space Flight Center provides high performance highly parallel processors, mass storage, and supporting infrastructure to a community of computational Earth and space scientists. Long running (days) and highly parallel (hundreds of CPUs) jobs are common in the workload. NCCS management structures batch queues and allocates resources to optimize system use and prioritize workloads. NCCS technical staff use a locally developed discrete event simulation tool to model the impacts of evolving workloads, potential system upgrades, alternative queue structures and resource allocation policies.

  11. Chaotic queue-based genetic algorithm for design of a self-tuning fuzzy logic controller

    NASA Astrophysics Data System (ADS)

    Saini, Sanju; Saini, J. S.

    2012-11-01

    This paper employs a chaotic queue-based method using logistic equation in a non-canonical genetic algorithm for optimizing the performance of a self-tuning Fuzzy Logic Controller, used for controlling a nonlinear double-coupled system. A comparison has been made with a standard canonical genetic algorithm implemented on the same plant. It has been shown that chaotic queue-method brings an improvement in the performance of the FLC for wide range of set point changes by a more profound initial population spread in the search space.

  12. Stochastic analyses arising from a new approach for closed queueing networks 

    E-print Network

    Sun, Feng

    2009-05-15

    the system size distribution at an arbitrary point in time and at departures for a ?(n)/G/1/N queue. The analysis is carried out using an embedded Markov chain approach. An algorithm is also developed that combines our analysis with the recursive method... and the service rates are allowed to be arbitrary functions of the current queue size using an embedded Markov chain approach. However, their results are difficult to be applied in computation, as pointed out by Gupta and Rao [18]. By approximating the general...

  13. An Optimization Model for the Selection of Bus-Only Lanes in a City.

    PubMed

    Chen, Qun

    2015-01-01

    The planning of urban bus-only lane networks is an important measure to improve bus service and bus priority. To determine the effective arrangement of bus-only lanes, a bi-level programming model for urban bus lane layout is developed in this study that considers accessibility and budget constraints. The goal of the upper-level model is to minimize the total travel time, and the lower-level model is a capacity-constrained traffic assignment model that describes the passenger flow assignment on bus lines, in which the priority sequence of the transfer times is reflected in the passengers' route-choice behaviors. Using the proposed bi-level programming model, optimal bus lines are selected from a set of candidate bus lines; thus, the corresponding bus lane network on which the selected bus lines run is determined. The solution method using a genetic algorithm in the bi-level programming model is developed, and two numerical examples are investigated to demonstrate the efficacy of the proposed model. PMID:26214001

  14. Common Traffic Violations of Bus Drivers in Urban China: An Observational Study

    PubMed Central

    Yang, Rendong; Huang, Yuanxiu; Zhang, Lin; Ning, Peishan; Cheng, Xunjie; Schwebel, David C.

    2015-01-01

    Objective To report common traffic violations in bus drivers and the factors that influence those violations in urban China. Methods We conducted an observational study to record three types of traffic violations among bus drivers in Changsha City, China: illegal stopping at bus stations, violating traffic light signals, and distracted driving. The behaviors of bus drivers on 32 routes (20% of bus routes in the city) were observed. A two-level Poisson regression examined factors that predicted bus driver violations. Results The incidence of illegal stopping at bus stations was 20.2%. Illegal stopping was less frequent on weekends, sunny days, and at stations with cameras, with adjusted incidence rate ratios (IRRs) of 0.81, 0.65 and 0.89, respectively. The incidence of violating traffic light signals was 2.2%, and was lower on cloudy than sunny days (adjusted IRR: 0.60). The incidence of distracted driving was 3.3%. The incidence of distracted driving was less common on cloudy days, rainy or snowy days, and foggy/windy/dusty days compared to sunny days, with adjusted IRRs of 0.54, 0.55 and 0.07, respectively. Conclusion Traffic violations are common in bus drivers in urban China and they are associated with the date, weather, and presence of traffic cameras at bus station. Further studies are recommended to understand the behavioral mechanisms that may explain bus driver violations and to develop feasible prevention measures. PMID:26372105

  15. An Optimization Model for the Selection of Bus-Only Lanes in a City

    PubMed Central

    Chen, Qun

    2015-01-01

    The planning of urban bus-only lane networks is an important measure to improve bus service and bus priority. To determine the effective arrangement of bus-only lanes, a bi-level programming model for urban bus lane layout is developed in this study that considers accessibility and budget constraints. The goal of the upper-level model is to minimize the total travel time, and the lower-level model is a capacity-constrained traffic assignment model that describes the passenger flow assignment on bus lines, in which the priority sequence of the transfer times is reflected in the passengers’ route-choice behaviors. Using the proposed bi-level programming model, optimal bus lines are selected from a set of candidate bus lines; thus, the corresponding bus lane network on which the selected bus lines run is determined. The solution method using a genetic algorithm in the bi-level programming model is developed, and two numerical examples are investigated to demonstrate the efficacy of the proposed model. PMID:26214001

  16. Discharging a DC bus capacitor of an electrical converter system

    DOEpatents

    Kajouke, Lateef A; Perisic, Milun; Ransom, Ray M

    2014-10-14

    A system and method of discharging a bus capacitor of a bidirectional matrix converter of a vehicle are presented here. The method begins by electrically shorting the AC interface of the converter after an AC energy source is disconnected from the AC interface. The method continues by arranging a plurality of switching elements of a second energy conversion module into a discharge configuration to establish an electrical current path from a first terminal of an isolation module, through an inductive element, and to a second terminal of the isolation module. The method also modulates a plurality of switching elements of a first energy conversion module, while maintaining the discharge configuration of the second energy conversion module, to at least partially discharge a DC bus capacitor.

  17. Bus Vent Design Evolution for the Solar Dynamics Observatory

    NASA Technical Reports Server (NTRS)

    Woronowicz, Michael

    2010-01-01

    As a spacecraft undergoes ascent in a launch vehicle, its pressure environment transitions from one atmosphere to high vacuum in a matter of minutes. Venting of internal cavities is necessary to prevent the buildup of pressure differentials across cavity walls. Opposing the need to vent these volumes freely into space are thermal, optical, and electrostatic requirements for limiting or prohibiting the intrusion of unwanted energy into the same cavities. Bus vent design evolution is discussed for the Solar Dynamics Observatory. Design changes were influenced by a number of factors and concerns, such as contamination control, electrostatic discharge, changes in bus material, and driving fairing ascent pressure for a launch vehicle that was just entering service as this satellite project had gotten underway.

  18. School bus transportation for students seated in wheelchairs.

    PubMed

    Buning, Mary Ellen; Karg, Patricia E

    2011-01-01

    For children with Individualized Education Plans (IEPs), transportation is considered a related service and a part of their education. This paper presents an overview of the current status of wheelchair transportation for students on school buses within the United States. The review includes the school transportation environment for wheelchair-seated students, applicable regulations and voluntary standards, primary safety issues for wheelchair-seated students, and key stakeholders roles in improving wheelchair transportation safety. Future actions to improve wheelchair transportation safety in school transportation are discussed, including the need to improve data collection, mandate payment for and use of RESNA WC19-compliant wheelchairs, improve training for bus operators and attendants, and require specialty certification for school bus operators who transport wheelchair-seated students. PMID:22430622

  19. Towards ubiquitous computing in Indonesia: automated bus system

    NASA Astrophysics Data System (ADS)

    Agushinta R., Dewi; Darmayantie, Astie; Rindhayanti, Hauliza; Permatasari, Jessica; H. S, D. Suryadi

    2011-10-01

    The traffic jam becomes the biggest problem in urban area especially in Jakarta as the capital city of Indonesia. This is due to inadequate facilities of public transportation so, people prefers to use the private vehicles. The government has given the solution to enhance that but it is still not effective and it made the situation of traffic jam became worst. This paper proposed the Automated Bus System (ABS) to improve the existing system and enhance the traffic jam problem. This bus system has the ability to ride on his own without relying on any human driver. It can recognize any obstacles and avoid any collision using stereo vision technology. RFID technology is used to improve the accuracy. Still, this whole system is monitored by human operators. If there is any failure beyond the ability of system, the human operators could recognize the problem.

  20. Heat storage for a bus petrol internal-combustion engine

    NASA Astrophysics Data System (ADS)

    Vasiliev, Leonard L.; Burak, Victor S.; Kulakov, Andry G.; Mishkinis, Donatas A.; Bohan, Pavel V.

    The heat storage (HS) system for pre-heating a bus petrol internal combustion engine to starting was mathematically modelled and experimentally investigated. The development of such devices is an extremely urgent problem especially for regions with a cold climate. We discuss how HS works on the effect of absorption and rejection of heat energy at a solid-liquid phase change of a HS substance. In the first part of the paper a numerical method to calculate the HS mass-dimensional parameters and their characteristics are described. In the experimental part of the paper results are given of experiments on the pre-heating device aiding to start a carburettor engine under operational conditions and analysis of data received. Practical confirmation of the theoretical development of HS devices for a bus engine for starting by pre-heating is given.

  1. BC Transit Fuel Cell Bus Project: Evaluation Results Report

    SciTech Connect

    Eudy, L.; Post, M.

    2014-02-01

    This report evaluates a fuel cell electric bus demonstration led by British Columbia Transit (BC Transit) in Whistler, Canada. BC Transit is collaborating with the California Air Resources Board and the U.S. Department of Energy's National Renewable Energy Laboratory to evaluate the buses in revenue service. This evaluation report covers two years of revenue service data on the buses from April 2011 through March 2013.

  2. Ring Bus Architecture for a Solid-State Recorder

    NASA Technical Reports Server (NTRS)

    Walker, W. John; Kopf, Edward; Cox, Brian

    2008-01-01

    A document concisely describes a ring bus architecture for a proposed solid-state recorder (SSR) that would serve as buffer of data to be transmitted from a spacecraft to Earth. This architecture would afford fault tolerance needed for reliable operation in an anticipated high-radiation environment in which traditional SSRs cannot operate reliably. Features of the architecture include one or more controller boards and multiple memory boards interconnected in a ringlike topology. The interconnections would be high-speed serial links complying with the Institute of Electrical and Electronics Engineers (IEEE) standard 1393 (which pertains to a spaceborne fiber-optic data bus). Accordingly, each controller and memory board would be equipped with an IEEE-1393-compliant ring-bus-interface unit. The ringlike topology and the multiplicity of memory boards (and, optionally, of controller boards) would afford the redundancy needed for fault tolerance. Each board would be a fault-containment region. The IEEE 1393 links could be routed so that the SSR would continue to function even in the event of multiple failures. This architecture would also support scalability over a wide range. In a fully redundant configuration, it could accommodate between 1 and 125 memory boards.

  3. Safety evaluation of a hydrogen fueled transit bus

    SciTech Connect

    Coutts, D.A.; Thomas, J.K.; Hovis, G.L.; Wu, T.T.

    1997-12-31

    Hydrogen fueled vehicle demonstration projects must satisfy management and regulator safety expectations. This is often accomplished using hazard and safety analyses. Such an analysis has been completed to evaluate the safety of the H2Fuel bus to be operated in Augusta, Georgia. The evaluation methods and criteria used reflect the Department of Energy`s graded approach for qualifying and documenting nuclear and chemical facility safety. The work focused on the storage and distribution of hydrogen as the bus motor fuel with emphases on the technical and operational aspects of using metal hydride beds to store hydrogen. The safety evaluation demonstrated that the operation of the H2Fuel bus represents a moderate risk. This is the same risk level determined for operation of conventionally powered transit buses in the United States. By the same criteria, private passenger automobile travel in the United States is considered a high risk. The evaluation also identified several design and operational modifications that resulted in improved safety, operability, and reliability. The hazard assessment methodology used in this project has widespread applicability to other innovative operations and systems, and the techniques can serve as a template for other similar projects.

  4. Pilot Survey of Subway and Bus Stop Noise Levels

    PubMed Central

    Neitzel, Richard; Barrera, Marissa A.; Akram, Muhammad

    2006-01-01

    Excessive noise exposure is a serious global urban health problem, adversely affecting millions of people. One often cited source of urban noise is mass transit, particularly subway systems. As a first step in determining risk within this context, we recently conducted an environmental survey of noise levels of the New York City transit system. Over 90 noise measurements were made using a sound level meter. Average and maximum noise levels were measured on subway platforms, and maximum levels were measured inside subway cars and at several bus stops for comparison purposes. The average noise level measured on the subway platforms was 86 ± 4 dBA (decibel-A weighting). Maximum levels of 106, 112, and 89 dBA were measured on subway platforms, inside subway cars, and at bus stops, respectively. These results indicate that noise levels in subway and bus stop environments have the potential to exceed recommended exposure guidelines from the World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA), given sufficient exposure duration. Risk reduction strategies following the standard hierarchy of control measures should be applied, where feasible, to reduce subway noise exposure. PMID:16802179

  5. A Dimensional Bus model for integrating clinical and research data

    PubMed Central

    Hum, Richard C; Murphy, James R

    2011-01-01

    Objectives Many clinical research data integration platforms rely on the Entity–Attribute–Value model because of its flexibility, even though it presents problems in query formulation and execution time. The authors sought more balance in these traits. Materials and Methods Borrowing concepts from Entity–Attribute–Value and from enterprise data warehousing, the authors designed an alternative called the Dimensional Bus model and used it to integrate electronic medical record, sponsored study, and biorepository data. Each type of observational collection has its own table, and the structure of these tables varies to suit the source data. The observational tables are linked to the Bus, which holds provenance information and links to various classificatory dimensions that amplify the meaning of the data or facilitate its query and exposure management. Results The authors implemented a Bus-based clinical research data repository with a query system that flexibly manages data access and confidentiality, facilitates catalog search, and readily formulates and compiles complex queries. Conclusion The design provides a workable way to manage and query mixed schemas in a data warehouse. PMID:21856687

  6. The AI Bus architecture for distributed knowledge-based systems

    NASA Technical Reports Server (NTRS)

    Schultz, Roger D.; Stobie, Iain

    1991-01-01

    The AI Bus architecture is layered, distributed object oriented framework developed to support the requirements of advanced technology programs for an order of magnitude improvement in software costs. The consequent need for highly autonomous computer systems, adaptable to new technology advances over a long lifespan, led to the design of an open architecture and toolbox for building large scale, robust, production quality systems. The AI Bus accommodates a mix of knowledge based and conventional components, running on heterogeneous, distributed real world and testbed environment. The concepts and design is described of the AI Bus architecture and its current implementation status as a Unix C++ library or reusable objects. Each high level semiautonomous agent process consists of a number of knowledge sources together with interagent communication mechanisms based on shared blackboards and message passing acquaintances. Standard interfaces and protocols are followed for combining and validating subsystems. Dynamic probes or demons provide an event driven means for providing active objects with shared access to resources, and each other, while not violating their security.

  7. Violence against metropolitan bus drivers and fare collectors in Brazil

    PubMed Central

    Assunção, Ada Ávila; de Medeiros, Adriane Mesquita

    2015-01-01

    OBJECTIVE To analyze the correlation between sociodemographic factors and working conditions of bus workers in a metropolitan area and violence against them. METHODS This cross-sectional study used a nonprobabilistic sample estimated according to the number of workers employed in bus companies located in three cities in the Belo Horizonte metropolitan region in 2012 (N = 17,470). Face-to-face interviews were conducted using a digital questionnaire. The factors associated with violence were analyzed in two stages using Poisson regression, according to each level. The magnitude of the association was evaluated using prevalence ratios with robust variance and a statistical significance of 5%, and 95% confidence intervals were obtained. RESULTS The study sample comprised 782 drivers and 691 fare collectors; 45.0% participants reported at least one act of violence in the workplace in the last 12 months, with passengers being predominantly responsible. The age of the bus workers was inversely associated with violence. Chronic diseases, sickness absenteeism, and working conditions were also associated with violence. CONCLUSIONS The findings on the correlation between violence and working conditions are essential for implementing prevention strategies by transportation service managers. PMID:25741657

  8. [Prevalence of post-traumatic stress disorder in bus drivers].

    PubMed

    Boyer, R; Brunet, A

    1996-01-01

    Many recent reports indicate that public transport employees constitute a group of workers at high risk of going through a traumatic event. Yet, very few scientific data on the impact of these events on this population are available. The authors present results of an epidemiological study conducted among Montreal bus drivers. A little more than a third of bus drivers have reported a traumatic event at work. Among the whole of traumatic events occurring during the course of their work, serious threats and assault constitute the majority of these events. Traumatic events are more frequent at work than in their private lives. The prevalence of PTSD for those exposed to a traumatic event at work is of 10.7% and of 21.3% for those bus drivers exposed to traumatic events in their private lives. Nine out of 100 drivers exposed to a traumatic event at work suffered a PTSD in the month preceding the study. When the authors consider the events occurring in the private lives, almost 15% of those exposed were victims of PTSD. When the two levels of expositions are reunited, 12% of those exposed presented a PTSD in the month preceding the research. PMID:8932226

  9. Dual Enrollment Academy Programs

    ERIC Educational Resources Information Center

    Gonzalez, Nicolas; Chavez, Guadalupe

    2009-01-01

    Dual Enrollment Engineering (DEEA) and Medical Science (DEMSA) Academies are two-year dual enrollment programs for high school students. Students explore engineering and medical careers through college coursework. Students prepare for higher education in engineering and medical fields while completing associate degrees in biology or engineering…

  10. A DiffServ Supporting And Distributed Dynamic Dual Round Robin Scheduling Algorithm on DS-CICQ

    NASA Astrophysics Data System (ADS)

    Xiuqin, Li; Luoheng, Yan; Julong, Lan

    A distributed dynamic dual round robin scheduling algorithm (DSDRR) that can support differential services is presented. For each scheduler, the strategy of double pointer and round robin is adopted and scheduling complexity is substantially reduced. Its quantum function, related to the status of input queue and priority, is a traffic-adaptive dynamic scheduling mechanism and is rather sensitive to the changing network; therefore, it has the traits of dynamics and fairness. It can better support differential services and guarantee the realization of QoS.

  11. Attendre: Mitigating Ill Effects of Race Conditions in OpenFlow via Queueing Mechanism

    E-print Network

    Ng, T. S. Eugene

    processes them in reverse. The Type 3 race (not depicted due to space limit) is ex- perienced by the networkAttendre: Mitigating Ill Effects of Race Conditions in OpenFlow via Queueing Mechanism Xiaoye Sun, a packet-in message is sent to the controller. This be- haviour results in various types of race conditions

  12. A Simple, Fast and Scalable Non-Blocking Concurrent FIFO Queue for Shared Memory

    E-print Network

    Tsigas, Philippas

    Systems Philippas Tsigas Yi Zhang Department of Computing Science Chalmers University of Technology for concurrent data structures, including FIFO queues, use some form of mutual exclusion (locking) to syn by allowing only one process (the holder of the lock of the data structure) at a time to access the data

  13. Technical Report no. 2003-01 Fast and Lock-Free Concurrent Priority Queues for

    E-print Network

    Tsigas, Philippas

    Technical Report no. 2003-01 Fast and Lock-Free Concurrent Priority Queues for Multi-Thread Systems1 Håkan Sundell Philippas Tsigas Department of Computing Science Chalmers University of Technology;Technical Report in Computing Science at Chalmers University of Technology and Göteborg University Technical

  14. Multiserver queueing for supervisory control of autonomous vehicles Nathan D. Powel and Kristi A. Morgansen

    E-print Network

    on a problem or task. The widespread use of unmanned aerial vehicles (UAVs) in surveillance gives an important data analysis. Most current UAV platforms, including Predator, ScanEagle, and GlobalHawk, require one. Single server queues have been used to analyze optimal relook policies for UAV surveillance [8], optimal

  15. Using a Queue to De-amortize Cuckoo Hashing in Adam Kirsch and Michael Mitzenmacher

    E-print Network

    Mitzenmacher, Michael

    Using a Queue to De-amortize Cuckoo Hashing in Hardware Adam Kirsch and Michael Mitzenmacher,michaelm}@eecs.harvard.edu Abstract--Cuckoo hashing combines multiple-choice hashing with the power to move elements, providing hash-amortization of cuckoo hashing suitable for hardware, and in particular for high-performance routers. I. INTRODUCTION

  16. Paper No. 03-3351 Real-Time Identification and Tracking of Traffic Queues

    E-print Network

    Hellinga, Bruce

    Paper No. 03-3351 Real-Time Identification and Tracking of Traffic Queues Based on Average Link University Avenue West, Waterloo, Ontario, Canada N2L 3G1 Phone: 519-888-4567, Ext. 6596; Fax: 519-888-6197 E Phone: 519-888-4567, Ext. 6596 E-mail: chclee@uwaterloo.ca Bruce Hellinga Associate Professor Department

  17. Fluid Queue Models of Battery Life Gareth L. Jones, Peter G. Harrison, Uli Harder, Tony Field

    E-print Network

    Imperial College, London

    Fluid Queue Models of Battery Life Gareth L. Jones, Peter G. Harrison, Uli Harder, Tony Field-mail:{gljones,uh,ajf,pgh}@doc.ic.ac.uk Abstract--We investigate how a power-save mode affects the battery life of a device subject transform of the battery life's probability density function is found and inverted numerically in particular

  18. Design of a Tree-Queue Model for a Large-Scale System

    NASA Astrophysics Data System (ADS)

    Park, Byungsung; Yoo, Jaeyeong; Kim, Hagbae

    In a large queuing system, the effect of the ratio of the filled data on the queue and waiting time from the head of a queue to the service gate are important factors for process efficiency because they are too large to ignore. However, many research works assumed that the factors can be considered to be negligible according to the queuing theory. Thus, the existing queuing models are not applicable to the design of large-scale systems. Such a system could be used as a product classification center for a home delivery service. In this paper, we propose a tree-queue model for large-scale systems that is more adaptive to efficient processes compared to existing models. We analyze and design a mean waiting time equation related to the ratio of the filled data in the queue. Based on simulations, the proposed model demonstrated improvement in process-efficiency, and it is more suitable to realistic system modeling than other compared models for large-scale systems.

  19. Max-pressure Controller for Stabilizing the Queues in6 Signalized Arterial Networks7

    E-print Network

    1 2 3 4 5 Max-pressure Controller for Stabilizing the Queues in6 Signalized Arterial Networks7 8 9.A. Fayazi, P. Varaiya 2 ABSTRACT1 The problem of arterial signal control is considered here. Urban of arterial traffic systems,5 is tested in simulations. Different modifications of the controller are analyzed

  20. Flow Control and Active Queue Management for Integrated Services in an Aeronautical Satellite Network

    E-print Network

    Baras, John S.

    Flow Control and Active Queue Management for Integrated Services in an Aeronautical Satellite}@umd.edu The IP-based broadband aeronautical satellite network will provide numerous new applications and services realizable. However the performance of data communication protocols and applications over aeronautical

  1. Fokker-Planck description for the queue dynamics of large tick stocks

    NASA Astrophysics Data System (ADS)

    Garèche, A.; Disdier, G.; Kockelkoren, J.; Bouchaud, J.-P.

    2013-09-01

    Motivated by empirical data, we develop a statistical description of the queue dynamics for large tick assets based on a two-dimensional Fokker-Planck (diffusion) equation. Our description explicitly includes state dependence, i.e., the fact that the drift and diffusion depend on the volume present on both sides of the spread. “Jump” events, corresponding to sudden changes of the best limit price, must also be included as birth-death terms in the Fokker-Planck equation. All quantities involved in the equation can be calibrated using high-frequency data on the best quotes. One of our central findings is that the dynamical process is approximately scale invariant, i.e., the only relevant variable is the ratio of the current volume in the queue to its average value. While the latter shows intraday seasonalities and strong variability across stocks and time periods, the dynamics of the rescaled volumes is universal. In terms of rescaled volumes, we found that the drift has a complex two-dimensional structure, which is a sum of a gradient contribution and a rotational contribution, both stable across stocks and time. This drift term is entirely responsible for the dynamical correlations between the ask queue and the bid queue.

  2. Active Methodologies in a Queueing Systems Course for Telecommunication Engineering Studies

    ERIC Educational Resources Information Center

    Garcia, J.; Hernandez, A.

    2010-01-01

    This paper presents the results of a one-year experiment in incorporating active methodologies in a Queueing Systems course as part of the Telecommunication Engineering degree at the University of Zaragoza, Spain, during the period of adaptation to the European Higher Education Area. A problem-based learning methodology has been introduced, and…

  3. E ective Bandwidths of Departure Processes from Queues with Time Varying Capacities

    E-print Network

    Chang, Cheng-Shang

    -Shang Chang #3; Dept. of Electrical Engineering National Tsing Hua University Hsinchu 30043 Taiwan, R.O.C. Tim Zajic CIMAT Apartado Postal 402 36000 Guanajuato, GTO. M#19;exico Abstract In this paper, we consider) x = #18; #3; ; (1) where q is the stationary queue length and #18; #3; is the decay rate. In Chang

  4. Optima and Equilibria for Traffic Flow on Networks with Backward Propagating Queues

    E-print Network

    Bressan, Alberto

    time or the route taken to reach destination. 1 Introduction Optimal traffic assignment and dynamicOptima and Equilibria for Traffic Flow on Networks with Backward Propagating Queues Alberto Bressan, 23]. For conservation law models of traffic flow on a network of roads, these problems were recently

  5. Average Number of Recirculations in SDL Constructions of Optical Priority Queues

    E-print Network

    Chang, Cheng-Shang

    1 Average Number of Recirculations in SDL Constructions of Optical Priority Queues Jay Cheng Abstract--In this letter, we derive the average number of times an optical packet recirculates through assignment. The analytical results on the average number of recirculations are further verified through

  6. On Constructions of Optical Queues with a Limited Number of Recirculations

    E-print Network

    Chang, Cheng-Shang

    On Constructions of Optical Queues with a Limited Number of Recirculations Jay Cheng, Cheng number of recirculations through the fibers in such SDL constructions. Such a limitation on the number of recirculations comes from practical feasibility considerations, such as crosstalk, power loss, amplified sponta

  7. Dynamic Allocation of Entities in Closed Queueing Networks: An Application to Debris Removal

    E-print Network

    Mendonça, David

    Dynamic Allocation of Entities in Closed Queueing Networks: An Application to Debris Removal James an empirical optimality gap. Further, because the system of interest, debris removal following natural to efficacy of a flat market context in inducing optimal behavior. I. INTRODUCTION Debris removal following

  8. Anchored Opportunity Queueing: A Low-Latency Scheduler for Fair Arbitration among Virtual Channels

    E-print Network

    Sethu, Harish

    ) scheduling. This paper presents a novel scheduling strategy, Anchored Opportunity Queueing (AOQ), which experienced by packets. The AOQ scheduler achieves lower average latencies by trying, as far as possible packet. The AOQ scheduler achieves provable fairness in the number of opportunities it offers to each

  9. A standard interface for debugger access to message queue information in MPI.

    SciTech Connect

    Cownie, J.; Gropp. W.

    1999-06-25

    This paper discusses the design and implementation of an interface that allows a debugger to obtain the information necessary to display the contents of the MPI message queues. The design has been implemented in the TotalView debugger, and dynamic libraries that conform to the interface exist for MPICH, as well as the proprietary MPI implementations from Compaq, IBM, and SGI.

  10. To appear in ACM Queue, 2006 Situation Models for Observing Human Activity

    E-print Network

    Crowley, James L.

    To appear in ACM Queue, 2006 Situation Models for Observing Human Activity James L. Crowley are described as scenarios composed of actors and objects within a network of situations. We provide formal definitions for the underlying concepts for situation models, and then propose a layered, component

  11. Admission Control and Pricing in a Queue with Batch Arrivals Utku Yildirim John J. Hasenbein1

    E-print Network

    Hasenbein, John

    ], in a seminal paper, used a single server queueing model to investigate a pricing problem for a monopoly. Naor on the structure of optimal policies. In a pair of papers, Chen and Frank [1, 2] analyzed a monopoly that can and the controller maximize their expected discounted return. In Chen and Frank [1], it is shown that a near monopoly

  12. The c/ rule for many-server queues with abandonment Rami Atar Chanit Giat Nahum Shimkin

    E-print Network

    Atar, Rami

    customer class i, the holding cost per unit time, the service rate and the abandonment rate are denoted, depending on the customer class i. Once admitted 1 #12;to service, a class-i customer is served state under any non-idling service scheme. Customer abandonment allows to stabilize the queue size even

  13. IEOR 3106: Fall 2014, Professor Whitt Time Reversibility and Queueing Networks, Thursday, November 6

    E-print Network

    Whitt, Ward

    6 This class is devoted to Sections 6 and 7 in the CTMC notes, specifically, pages 31-39, up is a structured CTMC, which has nice properties. The model elements are the external arrival processes need at each area. The entire system of 7 queues can also be modelled as a CTMC, but now it has special

  14. Efficient Simulation of a Tandem Queue with Server Slow-down

    E-print Network

    Al Hanbali, Ahmad

    Enschede, The Netherlands. E-mail address: {d.miretskiy, w.r.w.scheinhardt}@math.utwente.nl Postal address, The Netherlands. E-mail address: mmandjes@science.uva.nl 1 #12;from overflow, the first (upstream) server keeps specific, let us denote the number of jobs at server i by Xi(t), i = 1, 2. Jobs arrive at the first queue

  15. Large Deviations estimates for Polling and Weighted Fair Queueing service systems

    E-print Network

    Massoulié, Laurent

    â??e # Microsoft Research St George House, 1 Guildhall Street, Cambridge CB2 3ZH, UK lmassoul of tra#c classes employing either Weighted Fair Queueing or Weighted Round Robin service policy among. The system is also known as Weighted Round Robin (WRR), the weight associated with connection i being given

  16. /G/1 Queueing System with Disasters and Repairs under a Multiple Adapted Vacation Policy

    E-print Network

    Zazanis, Michael A.

    with disasters have been recognized as useful and natural models for com- munications systems and manufacturingAn MX /G/1 Queueing System with Disasters and Repairs under a Multiple Adapted Vacation Policy to disasters which occur inde- pendently according to a Poisson process but affect the system only when

  17. c 2007 by Samuel S. Stone. All rights reserved. MULTIVERSIONING IN THE STORE QUEUE

    E-print Network

    Frank, Matthew I.

    c 2007 by Samuel S. Stone. All rights reserved. #12;#12;MULTIVERSIONING IN THE STORE QUEUE IS THE ROOT OF ALL STORE-FORWARDING EVIL BY SAMUEL S. STONE B.S., Virginia Polytechnic Institute and State cache (FC), an address-indexed, set-associative alternative to the age-indexed, fully associative store

  18. Classes, Priorities and Fairness in Queueing Systems School of Computer Science

    E-print Network

    Levy, Hanoch

    Classes, Priorities and Fairness in Queueing Systems David Raz School of Computer Science Tel Brunswick, NJ, USA aviitzha@rutcor.rutgers.edu Hanoch Levy School of Computer Science Tel-Aviv University, the fairness aspects, which are inherent to any preferential system and highly important to customers, have

  19. On Maximum Rate Control of Worst-Case Weighted Fair Queueing Jeng Farn Lee1

    E-print Network

    Chen, Sheng-Wei

    On Maximum Rate Control of Worst-Case Weighted Fair Queueing Jeng Farn Lee1 , Yeali Sun2 , Meng Chang Chen1 1 Institute of Infromation Science,Academia Sinica 2 Department of Information Management, National Taiwan University TR-IIS-02-003 June 2002 Institude of Information Science Academia Sinica 1 #12

  20. M/G/FQ: STOCHASTIC ANALYSIS OF FAIR QUEUEING MOHAMMED HAWA AND DAVID W. PETR

    E-print Network

    Kansas, University of

    process, thus being more accurate in predicting the system status under normal operating conditionsM/G/FQ: STOCHASTIC ANALYSIS OF FAIR QUEUEING SYSTEMS MOHAMMED HAWA AND DAVID W. PETR Information the Generalized Processor Sharing (GPS) policy [2], Weighted Fair Queuing (WFQ) [2, 3], Self-Clocked Fair Queuing

  1. Production Task Queue Optimization Based on Multi-Attribute Evaluation for Complex Product Assembly Workshop

    PubMed Central

    Li, Lian-hui; Mo, Rong

    2015-01-01

    The production task queue has a great significance for manufacturing resource allocation and scheduling decision. Man-made qualitative queue optimization method has a poor effect and makes the application difficult. A production task queue optimization method is proposed based on multi-attribute evaluation. According to the task attributes, the hierarchical multi-attribute model is established and the indicator quantization methods are given. To calculate the objective indicator weight, criteria importance through intercriteria correlation (CRITIC) is selected from three usual methods. To calculate the subjective indicator weight, BP neural network is used to determine the judge importance degree, and then the trapezoid fuzzy scale-rough AHP considering the judge importance degree is put forward. The balanced weight, which integrates the objective weight and the subjective weight, is calculated base on multi-weight contribution balance model. The technique for order preference by similarity to an ideal solution (TOPSIS) improved by replacing Euclidean distance with relative entropy distance is used to sequence the tasks and optimize the queue by the weighted indicator value. A case study is given to illustrate its correctness and feasibility. PMID:26414758

  2. ClassBased Thresholds: Lightweight Active Router Queue Management for Multimedia Networking

    E-print Network

    Jeffay, Kevin

    Class­Based Thresholds: Lightweight Active Router­ Queue Management for Multimedia Networking ALL RIGHTS RESERVED #12; iii ABSTRACT MARK PARRIS: Class­Based Thresholds: Lightweight Active Router­ liorate congestion by arriving at an aggregate operating point where the generated load matches

  3. Heavy Tails in Multi-Server Queue1 SERGUEI FOSS foss@ma.hw.ac.uk

    E-print Network

    Foss, Serguei

    Heavy Tails in Multi-Server Queue1 SERGUEI FOSS foss@ma.hw.ac.uk Department of Actuarial 630090, Russia Abstract. In this paper, the asymptotic behaviour of the distribution tail of the station get asymptotics for the distribution tail of a stationary two-dimensional workload vector

  4. Stock Rationing in an M/Ek/1 Make-to-Stock Queue with Backorders

    E-print Network

    Karaesmen, Fikri

    Stock Rationing in an M/Ek/1 Make-to-Stock Queue with Backorders J.P. Gayon · Francis de V.duke.edu · fkaraesmen@ku.edu.tr We consider a single-item make-to-stock production system. The item is demanded status in a tractable way. We show different properties of the optimal stock allocation policy

  5. Testing and Evaluation of Batteries for a Fuel Cell Powered Hybrid Bus

    SciTech Connect

    Miller, J.F.; Webster, C.E.; Tummillo, A.F.; DeLuca, W.H.

    1997-05-01

    Argonne National Laboratory conducted performance characterization and life-cycle tests on various batteries to qualify them for use in a fuel cell/battery hybrid bus. On this bus, methanol-fueled, phosphoric acid fuel cells provide routine power needs, while batteries are used to store energy recovered during bus braking and to produce short-duration power during acceleration. Argonne carried out evaluation and endurance testing on several lead-acid and nickel/cadmium batteries selected by the bus developer as potential candidates for the bus application. Argonne conducted over 10,000 hours of testing, simulating more than 80,000 miles of fuel cell bus operation, for the nickel/cadmium battery, which was ultimately selected for use in the three hybrid buses built under the direction of H-Power Corp.

  6. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Third Results Reports

    SciTech Connect

    Eudy, L.; Chandler, K.

    2012-05-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. NREL has previously published two reports documenting the operation of the fuel cell bus in service. This report provides a summary of the results with a focus on the bus operation from July 2011 through January 2012.

  7. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Fourth Results Report

    SciTech Connect

    Eudy, L.; Chandler, K.

    2013-01-01

    SunLine Transit Agency, which provides public transit services to the Coachella Valley area of California, has demonstrated hydrogen and fuel cell bus technologies for more than 10 years. In May 2010, SunLine began demonstrating the advanced technology (AT) fuel cell bus with a hybrid electric propulsion system, fuel cell power system, and lithium-based hybrid batteries. This report describes operations at SunLine for the AT fuel cell bus and five compressed natural gas buses. The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is working with SunLine to evaluate the bus in real-world service to document the results and help determine the progress toward technology readiness. NREL has previously published three reports documenting the operation of the fuel cell bus in service. This report provides a summary of the results with a focus on the bus operation from February 2012 through November 2012.

  8. Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    KSC workers, with Center Director Roy Bridges (at right next to bus), head for the open door of the Zero Emissions (ZE) transit bus and a ride around the center. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. Available to employees for viewing and a ride, the ZE bus is also being used on tour routes at the KSC Visitor Complex Oct. 26-27.

  9. A study of multiplex data bus techniques for the space shuttle

    NASA Technical Reports Server (NTRS)

    Kearney, R. J.; Kalange, M. A.

    1972-01-01

    A comprehensive technology base for the design of a multiplexed data bus subsystem is provided. Extensive analyses, both analytical and empirical, were performed. Subjects covered are classified under the following headings: requirements identification and analysis; transmission media studies; signal design and detection studies; synchronization, timing, and control studies; user-subsystem interface studies; operational reliability analyses; design of candidate data bus configurations; and evaluation of candidate data bus designs.

  10. Multi-access fiber optic data bus using FDM/FSK

    NASA Technical Reports Server (NTRS)

    Zanger, H.

    1984-01-01

    The major thrust was to develop a T coupler with very low (0.1 0.2dB) in-line loss. This is essential to any multiaccess bus structure where the word multi implies fifteen or more nodes on the bus, and it is tacitly assumed to be a passive bus. (Reliability considerations tend to exclude the use of active nodes - repeater nodes.)

  11. Dual Credit/Dual Enrollment and Data Driven Policy Implementation

    ERIC Educational Resources Information Center

    Lichtenberger, Eric; Witt, M. Allison; Blankenberger, Bob; Franklin, Doug

    2014-01-01

    The use of dual credit has been expanding rapidly. Dual credit is a college course taken by a high school student for which both college and high school credit is given. Previous studies provided limited quantitative evidence that dual credit/dual enrollment is directly connected to positive student outcomes. In this study, predictive statistics…

  12. An Interactive Wireless Communication System for Visually Impaired People Using City Bus Transport

    PubMed Central

    Wang, Hsiao-Lan; Chen, Ya-Ping; Rau, Chi-Lun; Yu, Chung-Huang

    2014-01-01

    Visually impaired people have difficulty accessing information about public transportation systems. Several systems have been developed for assisting visually impaired and blind people to use the city bus. Most systems provide only one-way communication and require high-cost and complex equipment. The purpose of this study is to reduce the difficulties faced by visually impaired people when taking city buses, using an interactive wireless communication system. The system comprised a user module and a bus module to establish a direct one-to-one connection. When the user inputs 4-digit numbers, the user module immediately sends out the information. If the bus module receives the matched bus number, it buzzes and the warning LED flashes to notify the bus driver that someone is waiting to board on the bus. User tests were conducted by two visually impaired people in a simulated vehicle and a city bus. The success rate of interactive wireless communication, recognizing the arrival of the bus and boarding the correct bus reached 100% in all of the tests. The interactive wireless communication aid system is a valid and low-cost device for assisting visually impaired people to use city buses. PMID:24776720

  13. Analyzing the Relationship Between Bus Pollution Policies and Morbidity Using a Quasi-Experiment

    PubMed Central

    Ngo, Nicole S.

    2015-01-01

    Abstract Transit buses are used by millions of commuters every day, but they emit toxic diesel fumes. In 1988, the U.S. Environmental Protection Agency implemented emission standards for transit buses, which have been continually updated. Yet there is no quantitative evidence of the health benefits from these bus pollution policies due to data constraints and confounding variables. In this study, a quasi-experiment is used to exploit the geographic and temporal variation in emission standards by using bus vintage as a proxy for bus emissions. This is accomplished using a unique, rich panel data set, which includes daily information on bus vintage and route for the New York City Transit bus fleet between 2006 and 2009. This information is merged with daily data on emergency department (ED) visits for respiratory illnesses, which include patients’ residences at the census block level and exact admission date. Economic benefits resulting from these bus pollution policies are then estimated. Results show that stricter transit bus emission standards by the U.S. Environmental Protection Agency for particulate matter are associated with reduced ED visits for respiratory diseases for patients living within a few hundred feet of a bus route. These findings demonstrate that bus pollution policies have made critical improvements to public health. PMID:26376392

  14. An interactive wireless communication system for visually impaired people using city bus transport.

    PubMed

    Wang, Hsiao-Lan; Chen, Ya-Ping; Rau, Chi-Lun; Yu, Chung-Huang

    2014-05-01

    Visually impaired people have difficulty accessing information about public transportation systems. Several systems have been developed for assisting visually impaired and blind people to use the city bus. Most systems provide only one-way communication and require high-cost and complex equipment. The purpose of this study is to reduce the difficulties faced by visually impaired people when taking city buses, using an interactive wireless communication system. The system comprised a user module and a bus module to establish a direct one-to-one connection. When the user inputs 4-digit numbers, the user module immediately sends out the information. If the bus module receives the matched bus number, it buzzes and the warning LED flashes to notify the bus driver that someone is waiting to board on the bus. User tests were conducted by two visually impaired people in a simulated vehicle and a city bus. The success rate of interactive wireless communication, recognizing the arrival of the bus and boarding the correct bus reached 100% in all of the tests. The interactive wireless communication aid system is a valid and low-cost device for assisting visually impaired people to use city buses. PMID:24776720

  15. Superconducting link bus design for the accelerator project for upgrade of LHC

    SciTech Connect

    Nobrega, F.; Brandt, J.; Cheban, S.; Feher, S.; Kaducak, M.; Kashikhin, V.; Peterson, T.; /Fermilab

    2011-06-01

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. Fermi National Accelerator Laboratory in collaboration with Brookhaven National Laboratory was developing sub-systems for the upgrade of the LHC final focus magnet systems. Part of the upgrade called for various lengths of superconducting power transmission lines known as SC Links which were up to 100 m long. The SC Link electrically connects the current leads in the Distribution Feed Boxes to the interaction region magnets. The SC Link is an extension of the magnet bus housed within a cryostat. The present concept for the bus consists of 22 power cables, 4 x 13 kA, 2 x 7 kA, 8 x 2.5 kA and 8 x 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus design potentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus during installation at CERN. The round bus is very flexible and is suitable for pulling through the cryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

  16. Superconducting link bus design for the accelerator project for upgrade of LHC

    SciTech Connect

    Nobrega, F.; Brandt, J.; Cheban, S.; Feher, S.; Kaducak, M.; Kashikhin, V.; Peterson, T.; /Fermilab

    2010-08-01

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. Fermi National Accelerator Laboratory in collaboration with Brookhaven National Laboratory was developing sub-systems for the upgrade of the LHC final focus magnet systems. Part of the upgrade called for various lengths of superconducting power transmission lines known as SC Links which were up to 100 m long. The SC Link electrically connects the current leads in the Distribution Feed Boxes to the interaction region magnets. The SC Link is an extension of the magnet bus housed within a cryostat. The present concept for the bus consists of 22 power cables, 4 x 13 kA, 2 x 7 kA, 8 x 2.5 kA and 8 x 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus design potentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus during installation at CERN. The round bus is very flexible and is suitable for pulling through the cryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

  17. Superconducting link bus design for the accelerator project for upgrade of LHC

    NASA Astrophysics Data System (ADS)

    Nobrega, Alfred; Brandt, Jeff; Cheban, Sergey; Feher, Sandor; Kaducak, Mark; Kashikhin, Vadim; Peterson, Thomas J.

    2012-06-01

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. FermiNational Accelerator Laboratory in collaboration with Brookhaven National Laboratorywas developing sub-systems for the upgrade of the LHC final focus magnet systems. Partof the upgrade called for various lengths of superconducting power transmission linesknown as Superconducting (SC) Links which were up to 100 m long. The SC Linkelectrically connects the current leads in the Distribution Feed Boxes to the interactionregion magnets. The SC Link is an extension of the magnet bus housed within a cryostat.The present concept for the bus consists of 22 power cables, 4 × 13 kA, 2 × 7 kA, 8 × 2.5kA and 8 × 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus designpotentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus duringinstallation at CERN. The round bus is very flexible and is suitable for pulling through thecryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

  18. Analyzing the Relationship Between Bus Pollution Policies and Morbidity Using a Quasi-Experiment.

    PubMed

    Ngo, Nicole S

    2015-09-01

    Transit buses are used by millions of commuters every day, but they emit toxic diesel fumes. In 1988, the U.S. Environmental Protection Agency implemented emission standards for transit buses, which have been continually updated. Yet there is no quantitative evidence of the health benefits from these bus pollution policies due to data constraints and confounding variables. In this study, a quasi-experiment is used to exploit the geographic and temporal variation in emission standards by using bus vintage as a proxy for bus emissions. This is accomplished using a unique, rich panel data set, which includes daily information on bus vintage and route for the New York City Transit bus fleet between 2006 and 2009. This information is merged with daily data on emergency department (ED) visits for respiratory illnesses, which include patients' residences at the census block level and exact admission date. Economic benefits resulting from these bus pollution policies are then estimated. Results show that stricter transit bus emission standards by the U.S. Environmental Protection Agency for particulate matter are associated with reduced ED visits for respiratory diseases for patients living within a few hundred feet of a bus route. These findings demonstrate that bus pollution policies have made critical improvements to public health. PMID:26376392

  19. Dual doubled geometry

    NASA Astrophysics Data System (ADS)

    Bergshoeff, Eric A.; Riccioni, Fabio

    2011-08-01

    We probe doubled geometry with dual fundamental branes, i.e. solitons. Restricting ourselves first to solitonic branes with more than two transverse directions we find that the doubled geometry requires an effective wrapping rule for the solitonic branes which is dual to the wrapping rule for fundamental branes. This dual wrapping rule can be understood by the presence of Kaluza-Klein monopoles. Extending our analysis to supersymmetric solitonic branes with less than or equal to two transverse directions we show that such solitons are precisely obtained by applying the same dual wrapping rule to these cases as well. This extended wrapping rule cannot be explained by the standard Kaluza-Klein monopole alone. Instead, it suggests the existence of a class of generalized Kaluza-Klein monopoles in ten-dimensional string theory.

  20. BC Transit Fuel Cell Bus Project Evaluation Results: Second Report

    SciTech Connect

    Eudy, L.; Post, M.

    2014-09-01

    Second report evaluating a fuel cell electric bus (FCEB) demonstration led by British Columbia Transit (BC Transit) in Whistler, Canada. BC Transit is collaborating with the California Air Resources Board and the U.S. Department of Energy's National Renewable Energy Laboratory to evaluate the buses in revenue service. NREL published its first report on the demonstration in February 2014. This report is an update to the previous report; it covers 3 full years of revenue service data on the buses from April 2011 through March 2014 and focuses on the final experiences and lessons learned.

  1. DC Bus Regulation with a Flywheel Energy Storage System

    NASA Technical Reports Server (NTRS)

    Kenny, Barbara H.; Kascak, Peter E.

    2003-01-01

    This paper describes the DC bus regulation control algorithm for the NASA flywheel energy storage system during charge, charge reduction and discharge modes of operation. The algorithm was experimentally verified with results given in a previous paper. This paper presents the necessary models for simulation with detailed block diagrams of the controller algorithm. It is shown that the flywheel system and the controller can be modeled in three levels of detail depending on the type of analysis required. The three models are explained and then compared using simulation results.

  2. Increasing carbonmonoxide blood levels in Bangkok bus drivers

    SciTech Connect

    Saenghirunvattana, S.; Wananukul, W.; Mokkhavesa, C.; Opasi, N.

    1995-05-01

    In order to study the effects of air pollution in Bangkok, 31 bus drivers were examined and blood was drawn for measurement of carboxyhemoglobin (COHb) prior to and after work. The COHb level before work was 2.19{+-}2.46% (range 0.7.18). It had increased after work to 5.26{+-}2.52% (range 0-10.4) (p<0.001). Twenty-one drivers complained of chronic headaches, myalgia, and eye irritation during working hours. The COHb level was not statistically different between smokers and nonsmokers.

  3. Implementation of PMSM speed control software based on CAN bus

    NASA Astrophysics Data System (ADS)

    Cao, Wenlun; Chen, Bei; He, Yuyao

    2013-03-01

    In this paper, the driver's hardware structure based on TMS320F28335 is introduced, the control software flow of host computer based on CAN bus is designed, the rule of CAN communication protocol is fulfilled and accordingly the hybrid programming is realized in the background of low speed and large sinusoid operation. This system can realize the CAN communication setting, download the PID parameters to DSP, operate at constant rotate speed and at given large sinusoid rotate speed. Meanwhile the dynamical monitoring and alarm are implemented. Finally the real-time display and storage of measured current, voltage and rotate speed are completed well.

  4. 4.1 Intro: Time-Space Sw.; Input Q'ing w/o VOQ's 4.2 Input Queueing with VOQ's: Crossbar Scheduling

    E-print Network

    Markatos, Evangelos P.

    4.1 Intro: Time-Space Sw.; Input Q'ing w/o VOQ's 4.2 Input Queueing with VOQ's: Crossbar Scheduling-Space Switching and the family of Input Queueing Architectures #12;4.4, 4.5 - U. Crete - M. Katevenis - CS-534 2 4.4 CIOQ 4.5 CICQ Table of Contents: · Combined Input-Output Queueing (CIOQ) ­ Internal Speedup ­ Input

  5. Running time variability and resource allocation : a data-driven analysis of high-frequency bus operations

    E-print Network

    Sánchez-Martínez, Gabriel Eduardo

    2013-01-01

    Running time variability is one of the most important factors determining service quality and operating cost of high-frequency bus transit. This research aims to improve performance analysis tools currently used in the bus ...

  6. 25 CFR 39.711 - How does a school calculate annual bus transportation miles for residential students?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...false How does a school calculate annual bus transportation miles for residential students...711 How does a school calculate annual bus transportation miles for residential students...add together the miles driven for all buses used to transport students from...

  7. 49 CFR 1331.5 - Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus. 1331.5 Section 1331.5 Transportation...Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus. (a) Rate bureaus must comply...

  8. Plug-in vs. wireless charging: Life cycle energy and greenhouse gas emissions for an electric bus system

    E-print Network

    Mi, Chunting "Chris"

    -electric bus system. Life cycle inventory analysis of both plug-in and wireless charging hard- ware. The associated reduction of 12­16% in bus weight for the wireless buses can induce a reduction of 5

  9. Texas A&M Transportation Institute | 2012 Page | 1 Swift Bus Rapid Transit

    E-print Network

    Texas A&M Transportation Institute | 2012 Page | 1 Swift Bus Rapid Transit (Community Transit and Everett Transit) SUMMARY Swift bus rapid transit (BRT) is a partnership between two transit agencies (Community Transit and Everett Transit) in the Central Puget Sound Region, WA. Community Transit directly

  10. Mobile Journey Planning for Bus Passengers Desmond Rainsford and William A Mackaness

    E-print Network

    form of public transport. The three alternatives, most commonly available to people wishing to navigate planners are available for urban bus travellers and tend to restrict users to a limited number of journey endpoints. This is due to the challenges of modelling urban bus networks that are dynamic, (varying

  11. Evoking Emotions and Unpacking Layered Histories through Young Children's Illustrations of Racial Bus Segregation

    ERIC Educational Resources Information Center

    Kuby, Candace R.

    2013-01-01

    Drawing on theories of multi-modality and critical visual literacy, this article focuses on images that five-and six year-olds painted in a class-made book, Voice on the Bus, about racial segregation. The article discusses how children used illustrations to convey their understandings of Rosa Parks' bus arrest in Alabama. A post-structural view…

  12. 49 CFR Appendix A to Part 665 - Tests To Be Performed at the Bus Testing Facility

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... gross vehicle weight, with one wheel on top of a curb and then in a pothole. This test should be... the bus with a distributed load equal to 2.5 times the load applied for the gross weight portions of... static tension load equal to 1.2 times the curb weight should be applied to the bus towing...

  13. The prediction of bus arrival time using Automatic Vehicle Location Systems data 

    E-print Network

    Jeong, Ran Hee

    2005-02-17

    , schedule adherence by time period, and traffic congestion which were critical to predict accurate bus arrival times. The test bed was a bus route running in the downtown of Houston, Texas. A historical based model, regression models, and artificial.................................................................5 1.3.2 Collect Data and Define Test Bed......................................................5 1.3.3 Reduce Data and Correct Errors ........................................................5 1...

  14. NREL's Hydrogen-Powered Bus Serves as Showcase for Advanced Vehicle Technologies (AVT) (Brochure)

    SciTech Connect

    Not Available

    2010-08-01

    Brochure describes the hydrogen-powered internal combustion engine (H2ICE) shuttle bus at NREL. The U.S. Department of Energy (DOE) is funding the lease of the bus from Ford to demonstrate market-ready advanced technology vehicles to visitors at NREL.

  15. Drive Cycle Analysis, Measurement of Emissions and Fuel Consumption of a PHEV School Bus: Preprint

    SciTech Connect

    Barnitt, R.; Gonder, J.

    2011-04-01

    The National Renewable Energy Laboratory (NREL) collected and analyzed real-world school bus drive cycle data and selected similar standard drive cycles for testing on a chassis dynamometer. NREL tested a first-generation plug-in hybrid electric vehicle (PHEV) school bus equipped with a 6.4L engine and an Enova PHEV drive system comprising a 25-kW/80 kW (continuous/peak) motor and a 370-volt lithium ion battery pack. A Bluebird 7.2L conventional school bus was also tested. Both vehicles were tested over three different drive cycles to capture a range of driving activity. PHEV fuel savings in charge-depleting (CD) mode ranged from slightly more than 30% to a little over 50%. However, the larger fuel savings lasted over a shorter driving distance, as the fully charged PHEV school bus would initially operate in CD mode for some distance, then in a transitional mode, and finally in a charge-sustaining (CS) mode for continued driving. The test results indicate that a PHEV school bus can achieve significant fuel savings during CD operation relative to a conventional bus. In CS mode, the tested bus showed small fuel savings and somewhat higher nitrogen oxide (NOx) emissions than the baseline comparison bus.

  16. Assistant Drivers Instructor's Manual. New York State School Bus Driver Training Program.

    ERIC Educational Resources Information Center

    Rogers, R. Delano

    This assistant drivers instructor's manual for a school bus driver instructional program accompanies a student study guide--see Note. The manual is divided into five units: (1) Developing a Positive Attitude Toward Handicapping Conditions, (2) Who Are the Children with Handicapping Conditions, (3) Responsibilities of the School Bus Transportation…

  17. Guidelines for Bus Evacuation and Classroom Instruction in Safe Riding Practices.

    ERIC Educational Resources Information Center

    Sowash, Fred W.

    This booklet is intended to aid local school district administrators by providing guidelines for implementing programs on school bus evacuation and safe riding practices. Included are general guidelines for developing and implementing classroom instruction in safe riding practices, detailed guidelines for familiarizing bus drivers and students…

  18. 75 FR 66686 - Federal Motor Vehicle Safety Standards; Seat Belt Assembly Anchorages, School Bus Passenger...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-29

    ...Mr. Charles Hott, Office of Crashworthiness Standards...Ms. Dorothy Nakama, Office of the Chief Counsel...Applying FMVSS No. 207 to Small School Buses c. Minimum...school bus safety and medical organizations and associations...b. Defining a ``Small'' School Bus...

  19. I2C 2005-1 Demonstration Board I2C-bus Protocol

    E-print Network

    Berns, Hans-Gerd

    and used by all major IC manufacturers · Multi-master capable bus with arbitration feature · Master-Slave code · The slave can operate as a: ­ receiver (slave ­ receiver) ­ transmitter (slave ­ transmitter) I2C Introduction #12;I2C 2005-1 Demonstration Board Oct, 2006 3 I2C-Bus Protocol Basic Start Slave

  20. Modeling Shared Cache and Bus in Multi-cores for Timing Analysis

    E-print Network

    Mitra, Tulika

    Modeling Shared Cache and Bus in Multi-cores for Timing Analysis Sudipta Chattopadhyay Abhik. The key to solving this problem is to accurately model the timing ef- fects of shared resources in multi-cores, namely shared cache and bus. In this paper, we provide an integrated timing anal- ysis framework

  1. PSCR: A Coherence Protocol for Eliminating Passive Sharing in Shared-Bus

    E-print Network

    Giorgi, Roberto

    PSCR: A Coherence Protocol for Eliminating Passive Sharing in Shared-Bus Shared and parallel applications. Shared-bus shared-memory multiprocessor can be used to speed-up the execution of private data into different caches produce an undesired sharing, named passive sharing. The copies due

  2. Through Rain, Sleet, Ice, and Snow, the Walking School Bus Still Must Go!

    ERIC Educational Resources Information Center

    Paquette, Kelli R.

    2007-01-01

    In this article, the author describes the walking school bus--a physically active and safe method in which young learners can travel to and from school while accompanied by adult volunteers. The walking school bus provides a safe and healthy way for elementary-age children to travel to and from school. Many families who live within walking…

  3. 77 FR 74452 - Bus Testing: Calculation of Average Passenger Weight and Test Vehicle Weight

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-14

    ...No. FTA-2011-0015] RIN 2132-AB01 Bus Testing: Calculation of Average Passenger...Transit Administration's (FTA's) bus testing regulation to increase the assumed...passenger weight value used for ballasting test buses from the current value of 150 pounds...

  4. 49 CFR 571.221 - Standard No. 221, School bus body joint strength.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Standard No. 221, School bus body joint strength. 571.221 Section 571.221 Transportation...Vehicle Safety Standards § 571.221 Standard No. 221, School bus body joint strength. S5.2.1 The requirements of...

  5. Using School Bus Discipline Referral Data in Decision Making: Two Case Studies

    ERIC Educational Resources Information Center

    Hirsch, Edward J.; Lewis-Palmer, Teri; Sugai, George; Schnacker, Lance

    2004-01-01

    Public schools are responsible for providing a safe, structured environment that is conducive to learning. This requirement encompasses a variety of settings, including school bus transportation. However, limited research exists to indicate best practices for designing and implementing behavior programs for school bus transportation. The…

  6. 77 FR 25529 - Over-the-Road Bus Accessibility Program Grants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-30

    ...Transit Administration Over-the-Road Bus Accessibility Program Grants AGENCY: Federal...Year (FY) 2012 for the Over-the-Road Bus Accessibility (OTRB) Program, initially...private operators of over-the-road buses to finance the incremental capital...

  7. The Overall Energy Balance of the Hydrogen Bus in Berkeley, CA

    E-print Network

    Patzek, Tadeusz W.

    The Overall Energy Balance of the Hydrogen Bus in Berkeley, CA T. W. Patzek1 , K. Kappler, A. F-friendly alternative to diesel buses. In Berkeley, a hydrogen bus system consists of grid electricity, electrolyzer will cost $1.5 billion over 5 years (11). 1 To whom correspondence should be addressed, patzek@patzek.berkeley

  8. SN54F245, SN74F245 OCTAL BUS TRANSCEIVERS

    E-print Network

    Berns, Hans-Gerd

    SN54F245, SN74F245 OCTAL BUS TRANSCEIVERS WITH 3-STATE OUTPUTS SDFS010A ­ MARCH 1987 ­ REVISED These octal bus transceivers are designed for asynchronous communication between data buses. The devices are effectively isolated. The SN74F245 is available in TI's shrink small-outline package (DB), which provides

  9. 46 CFR 112.05-3 - Main-emergency bus-tie.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... other source of electric power, except for interlock systems for momentary transfer of loads; and (c) If... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS General § 112.05-3 Main-emergency bus-tie. Each bus-tie between a main...

  10. 46 CFR 112.05-3 - Main-emergency bus-tie.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... other source of electric power, except for interlock systems for momentary transfer of loads; and (c) If... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS General § 112.05-3 Main-emergency bus-tie. Each bus-tie between a main...

  11. 46 CFR 112.05-3 - Main-emergency bus-tie.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... other source of electric power, except for interlock systems for momentary transfer of loads; and (c) If... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS General § 112.05-3 Main-emergency bus-tie. Each bus-tie between a main...

  12. 46 CFR 112.05-3 - Main-emergency bus-tie.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... other source of electric power, except for interlock systems for momentary transfer of loads; and (c) If... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS General § 112.05-3 Main-emergency bus-tie. Each bus-tie between a main...

  13. 46 CFR 112.05-3 - Main-emergency bus-tie.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... other source of electric power, except for interlock systems for momentary transfer of loads; and (c) If... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING EMERGENCY LIGHTING AND POWER SYSTEMS General § 112.05-3 Main-emergency bus-tie. Each bus-tie between a main...

  14. [Drugs use assessment in a group of bus drivers].

    PubMed

    Maccà, I; Maso, S; Marcuzzo, G; Bartolucci, G B

    2012-01-01

    Bus driver is one of those tasks inherent transport activity, which involves special risks to safety and health of others and for which it is necessary, according to art. 41 of Decree No. 81/08, to check the consumption of psychoactive substances during the health surveillance. This assumption was investigated in a group of 461 bus drivers of a large trucking company. In medical history, one subject reported a previous history of opiate addiction and another, in the past, occasional taking of cannabis, and at the time of the visit, in no cases the objectivity has shown intoxication or abstinence signs, or signs of parenteral injection. Laboratory tests were found positive in one case of screening texts, not confirmed by subsequent laboratory analysis and a case of positive analysis for confirmation. The worker, temporarily suspended from driving and taken over by the Service for Drug Addiction of competence, was then reinstated in his job, having held that the absence of drug addiction. PMID:23405659

  15. A Conceptual Design for a Reliable Optical Bus (ROBUS)

    NASA Technical Reports Server (NTRS)

    Miner, Paul S.; Malekpour, Mahyar; Torres, Wilfredo

    2002-01-01

    The Scalable Processor-Independent Design for Electromagnetic Resilience (SPIDER) is a new family of fault-tolerant architectures under development at NASA Langley Research Center (LaRC). The SPIDER is a general-purpose computational platform suitable for use in ultra-reliable embedded control applications. The design scales from a small configuration supporting a single aircraft function to a large distributed configuration capable of supporting several functions simultaneously. SPIDER consists of a collection of simplex processing elements communicating via a Reliable Optical Bus (ROBUS). The ROBUS is an ultra-reliable, time-division multiple access broadcast bus with strictly enforced write access (no babbling idiots) providing basic fault-tolerant services using formally verified fault-tolerance protocols including Interactive Consistency (Byzantine Agreement), Internal Clock Synchronization, and Distributed Diagnosis. The conceptual design of the ROBUS is presented in this paper including requirements, topology, protocols, and the block-level design. Verification activities, including the use of formal methods, are also discussed.

  16. Tunable frequency combs based on dual microring resonators

    E-print Network

    Miller, Steven A; Ramelow, Sven; Luke, Kevin; Dutt, Avik; Farsi, Alessandro; Gaeta, Alexander L; Lipson, Michal

    2015-01-01

    In order to achieve efficient parametric frequency comb generation in microresonators, external control of coupling between the cavity and the bus waveguide is necessary. However, for passive monolithically integrated structures, the coupling gap is fixed and cannot be externally controlled, making tuning the coupling inherently challenging. We design a dual-cavity coupled microresonator structure in which tuning one ring resonance frequency induces a change in the overall cavity coupling condition. We demonstrate wide extinction tunability with high efficiency by engineering the ring coupling conditions. Additionally, we note a distinct dispersion tunability resulting from coupling two cavities of slightly different path lengths, and present a new method of modal dispersion engineering. Our fabricated devices consist of two coupled high quality factor silicon nitride microresonators, where the extinction ratio of the resonances can be controlled using integrated microheaters. Using this extinction tunability...

  17. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Second Results Report and Appendices

    SciTech Connect

    Eudy, L.; Chandler, K.

    2011-10-01

    This report describes operations at SunLine Transit Agency for their newest prototype fuel cell bus and five compressed natural gas (CNG) buses. In May 2010, SunLine began operating its sixth-generation hydrogen fueled bus, an Advanced Technology (AT) fuel cell bus that incorporates the latest design improvements to reduce weight and increase reliability and performance. The agency is collaborating with the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to evaluate the bus in revenue service. This is the second results report for the AT fuel cell bus since it was placed in service, and it focuses on the newest data analysis and lessons learned since the previous report. The appendices, referenced in the main report, provide the full background for the evaluation. They will be updated as new information is collected but will contain the original background material from the first report.

  18. Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    KSC employees, along with Center Director Roy Bridges (second from left), view the hydrogen-oxygen driven engine powering a Zero Emissions (ZE) transit bus. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. Available for viewing by employees, the ZE bus is also being used on tour routes at the KSC Visitor Complex Oct. 26-27.

  19. Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In front of the Headquarters Building at KSC, Center Director Roy Bridges (left) looks at the hydrogen-oxygen driven engine powering a Zero Emissions (ZE) transit bus. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by- product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. Available for viewing by employees, the ZE bus is also being used on tour routes at the KSC Visitor Complex Oct. 26-27.

  20. Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC

    NASA Technical Reports Server (NTRS)

    1999-01-01

    On view in front of the Headquarters Building, the Zero Emissions (ZE) transit bus attracts an interested group of employees, including Center Director Roy Bridges (second from left in foreground). Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. Available for viewing by employees, the ZE bus is also being used on tour routes at the KSC Visitor Complex Oct. 26-27.

  1. Hydrogen-oxygen driven Zero Emissions bus drives around KSC Visitor Complex

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The Zero Emissions (ZE) transit bus passes a mock-up orbiter named Explorer on a trek through the KSC Visitor Complex. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. The ZE bus is being used on tour routes at the KSC Visitor Complex for two days to introduce the public to the concept.

  2. Hydrogen-oxygen driven Zero Emissions bus drives around KSC Visitor Complex

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The Zero Emissions (ZE) transit bus tours the KSC Visitor Complex for a test ride. In the background are a mock-up orbiter named Explorer (left) and a stack of solid rocket boosters and external tank (right), typically used on Shuttle launches. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. The ZE bus is being used on tour routes at the KSC Visitor Complex for two days to introduce the public to the concept.

  3. Development of the Simulator for the On-demand Bus Introduction

    NASA Astrophysics Data System (ADS)

    Tsubouchi, Kota; Yamato, Hiroyuki; Hiekata, Kazuo

    This paper reports the development of the simulator which helps for the introduction of On-demand Bus service. On-demand bus system is new convenient transportation system that passengers will be transported by the vehicles after they reserve a seat. The design of the introduction of On-demand Bus service is very important for the efficient operation, but there is no established theory because it is a new transportation system. The developed simulator performs well to design the On-demand Bus introduction. The result of the real field test in Moriyama City shows the answer from the simulator is realistic and it is useful information for designing efficient On-demand Bus introduction.

  4. Customer Equilibrium and Optimal Strategies in an M/M/1 Queue with Dynamic Service Control

    E-print Network

    Dimitrakopoulos, Y

    2011-01-01

    We consider the problem of customer equilibrium strategies in an M/M/1 queue under dynamic service control. The service rate switches between a low and a high value depending on system congestion. Arriving customers do not observe the system state at the moment of arrival. We show that due to service rate variation, the customer equilibrium strategy is not generally unique, and derive an upper bound on the number of possible equilibria. For the problem of social welfare optimization, we numerically analyze the relationship between the optimal arrival rate, which maximizes the overall welfare of the customers, and the equilibrium ones as a function of various parameter values. We finally derive analytic solutions for the special case where the service rate switch occurs when the queue ceases to be empty.

  5. 76 FR 28947 - Bus Testing: Calculation of Average Passenger Weight and Test Vehicle Weight, and Public Meeting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-19

    ...No. FTA-2011-0015] RIN 2132-AB01 Bus Testing: Calculation of Average Passenger...technical information, Gregory Rymarz, Bus Testing Program Manager, Office of Research...Register (76 FR 13850) proposing to amend its bus testing procedures to more accurately...

  6. Delay decomposition at a single server queue with constant service time and multiple inputs

    NASA Technical Reports Server (NTRS)

    Ziegler, C.; Schilling, D. L.

    1978-01-01

    Two network consisting of single server queues, each with a constant service time, are considered. The external inputs to each network are assumed to follow some general probability distribution. Several interesting equivalencies that exist between the two networks considered are derived. This leads to the introduction of an important concept in delay decomposition. It is shown that the waiting time experienced by a customer can be decomposed into two basic components called self-delay and interference delay.

  7. Homogeneous FiniteSource Retrial Queues with Search of Customers from the Orbit

    E-print Network

    Sztrik, János

    Dimensional Continuous Markov Chain (CTMC):( ) g X(t) = (C(t), N(t)), where C(t)=1 if the server is busy and 0 if idle, and N(t) is the number of customers in the orbit at time t. G hi l R t ti f CTMC f K 4g Graphical Representation of CTMC for K=4: Parameters: K=4 Sources : Arrival Rate 7MMB 2008 Wüchner Retrial Queues µ

  8. A queueing theory description of fat-tailed price returns in imperfect financial markets

    NASA Astrophysics Data System (ADS)

    Lamba, H.

    2010-09-01

    In a financial market, for agents with long investment horizons or at times of severe market stress, it is often changes in the asset price that act as the trigger for transactions or shifts in investment position. This suggests the use of price thresholds to simulate agent behavior over much longer timescales than are currently used in models of order-books. We show that many phenomena, routinely ignored in efficient market theory, can be systematically introduced into an otherwise efficient market, resulting in models that robustly replicate the most important stylized facts. We then demonstrate a close link between such threshold models and queueing theory, with large price changes corresponding to the busy periods of a single-server queue. The distribution of the busy periods is known to have excess kurtosis and non-exponential decay under various assumptions on the queue parameters. Such an approach may prove useful in the development of mathematical models for rapid deleveraging and panics in financial markets, and the stress-testing of financial institutions.

  9. Novel low cost standardized Nano-Satellite structure bus for LEO missions

    NASA Astrophysics Data System (ADS)

    Anubhav, T.; Sarwesh, P.; Narayan, V.; Varma, P. A.; Prasad, R. A.; Loganathan, M.; Rao, D. N.; Sriram, S.; Venkatesh, M.

    This paper focuses on SRMSAT STRUCTURE BUS which is a standardized Nano-Satellite structure bus. It provides a standard platform for a wide variety of missions in LEO and can be realized in a very short developmental period. The bus was designed and developed for SRMSAT, the SRM University (Sri Ramaswamy Memorial University) student Nano-Satellite, by the undergraduate students and faculty of SRM University in collaboration with Indian Space Research Organization (ISRO). The bus can support payloads up to a mass of 20kg. SRMSAT STRUCTURE BUS has a mass of around 6 kg and dimensions 280mm × 280mm × 280mm with an available volume of 11000 cc. Vibration Testing of the bus has been performed upto 6.7 gRMS. This makes the satellite capable of being launched by any launch vehicle in the world. An innovative PCB mounting design has been introduced in this structure bus which facilitates mounting of a maximum 7 PCB trays independently, each tray capable of holding a 250 mm2 PCB. Structural analysis of SRMSAT STRUCTURE BUS was done using NX Nastran. The boundary conditions for each analysis were defined based on the loading conditions as specified by the launcher, PSLV (Polar Satellite Launch Vehicle). Optimization of each individual component was performed by maintaining a minimum threshold between the local frequencies of the component and global frequencies of the entire satellite. Static, Modal, Harmonic and Random Vibration analysis of the structure bus was performed. This paper also describes the methodology followed in the static and dynamic analysis of the structure bus to finalize the design. The results have been tested and validated at ISRO Satellite Centre, Bangalore with around 90% accuracy and the structure has been certified as a standard structure bus for Nano-satellite missions. In terms of expandability, this structure bus is capable of accommodating deployable solar panels. Also, the payload mounting is not only restricted to th- bottom deck but can also be done in the top or side decks as required for specific missions. This enhances the scope of small satellites which has not been possible with previous satellites of the same size. SRMSAT which utilized this bus was launched on-board PSLV C-18 on 12th October 2011 with the scientific objective of measuring greenhouse gases, namely CO2 and H2O.

  10. Conformally Dual to Inflation

    E-print Network

    Piao, Yun-Song

    2011-01-01

    It is showed by a conformal rescaling that the inflationary background can be dual to a slowly expanding background, which is almost Minkowski and described by a conformal field theory conformally coupled to gravity. It is proved that the primordial curvature perturbation and tensor perturbation generated during these two conformally equivalent backgrounds are completely equal, and the scale invariance of perturbations is determined by the conformal invariance of field theory in slowly expanding background. In dual slowly expanding scenario, the primordial universe is asymptotical to a static state in infinite past. We discuss the implication of the results obtained.

  11. Conformally Dual to Inflation

    E-print Network

    Yun-Song Piao

    2011-12-16

    It is showed by a conformal rescaling that the inflationary background can be dual to a slowly expanding background, which is almost Minkowski and described by a conformal field theory conformally coupled to gravity. It is proved that the primordial curvature perturbation and tensor perturbation generated during these two conformally equivalent backgrounds are completely equal, and the scale invariance of perturbations is determined by the conformal invariance of field theory in slowly expanding background. In dual slowly expanding scenario, the primordial universe is asymptotical to a static state in infinite past. We discuss the implication of the results obtained.

  12. Dual-Mode Combustor

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J (Inventor); Dippold, Vance F (Inventor)

    2013-01-01

    A new dual-mode ramjet combustor used for operation over a wide flight Mach number range is described. Subsonic combustion mode is usable to lower flight Mach numbers than current dual-mode scramjets. High speed mode is characterized by supersonic combustion in a free-jet that traverses the subsonic combustion chamber to a variable nozzle throat. Although a variable combustor exit aperture is required, the need for fuel staging to accommodate the combustion process is eliminated. Local heating from shock-boundary-layer interactions on combustor walls is also eliminated.

  13. Dual Diagnosis: Substance Abuse and Mental Illness

    MedlinePLUS

    ... Mental Health Conditions Related Conditions Dual Diagnosis Dual Diagnosis Dual diagnosis is a term for when someone ... chemistry and behavior. How Common is a Dual Diagnosis? About a third of all people experiencing mental ...

  14. Dual approximations in optimal control

    NASA Technical Reports Server (NTRS)

    Hager, W. W.; Ianculescu, G. D.

    1984-01-01

    A dual approximation for the solution to an optimal control problem is analyzed. The differential equation is handled with a Lagrange multiplier while other constraints are treated explicitly. An algorithm for solving the dual problem is presented.

  15. A High Efficiency DC Bus Regulator/RPC for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Birchenough, Arthur G.

    2003-01-01

    DC bus voltage regulation may be required in future high powered spacecraft due to the length of the busses or because they are not generated at precise voltage levels. In these cases the regulation range is often only a few percent increase or decrease, but conventional DC voltage regulators switch all the power passing through them, and this level of power switched determines the size and losses in the regulator. A recently developed concept used a low power DC-DC converter in series with the bs to raise or lower the bus voltage over a small range. This partial power processing technique combines the small size and power losses of the low power converter with the ability to regulate, (over a small range) a high power bus. The Series Connected Buck Boost Regulator (SCBBR) described herein provides bus regulation with an efficiency of 98%. The circuit also provides bus switching and overcurrent limiting functions of a Remote Power Controller (RPC). This paper described the circuit design and performance of a breadboard SCBBR configured as a bus voltage regulator providing plus of minus 40% voltage regulation range, bus switching, and overload limiting.

  16. Prevalence and factors associated with road traffic crash among bus drivers in Hanoi, Vietnam.

    PubMed

    La, Quang Ngoc; Lee, Andy H; Meuleners, Lynn B; Van Duong, Dat

    2013-01-01

    Bus provides a main mode of public transport in Vietnam, but the risk of road traffic crash for bus drivers is unknown. This retrospective study estimated the crash prevalence among bus drivers in Hanoi, Vietnam, and identified driver characteristics affecting their crashes. Information on bus crashes for the period 2006-2009 was collected by interviewing drivers from five bus companies in Hanoi using a structured questionnaire. Logistic regression analysis was performed to determine pertinent risk factors affecting the crash prevalence for bus drivers. Of the total 365 participants recruited, 73 drivers reported 76 crashes, giving an overall crash prevalence of 20%. Among the crashed group, three drivers (4%) were involved in two crashes during the past 3 years. Crashes mainly occurred on streets or local roads (81%). Migrant worker (adjusted odds ratio (OR) 4.26, 95% confidence interval (CI) 2.20-8.25) and insufficient income perceived (OR 2.60, 95% CI 1.37-4.93) were identified to be significantly associated with the crash risk. Further prospective and qualitative studies are needed to provide detailed crash characteristics as well as behaviour and perception of bus drivers, so that an effective intervention can be developed to improve road safety and to prevent traffic injury of these drivers. PMID:23190322

  17. Modeling a bus through a sequence of traffic lights

    NASA Astrophysics Data System (ADS)

    Villalobos, Jorge; Muñoz, Víctor; Rogan, José; Zarama, Roberto; Penagos, Juan Felipe; Toledo, Benjamín; Valdivia, Juan Alejandro

    2015-07-01

    We propose a model of a bus traveling through a sequence of traffic lights, which is required to stop between the traffic signals to pick up passengers. A two dimensional model, of velocity and traveled time at each traffic light, is constructed, which shows non-trivial and chaotic behaviors for realistic city traffic parameters. We restrict the parameter values where these non-trivial and chaotic behaviors occur, by following analytically and numerically the fixed points and period 2 orbits. We define conditions where chaos may arise by determining regions in parameter space where the maximum Lyapunov exponent is positive. Chaos seems to occur as long as the ratio of the braking and accelerating capacities are greater than about ˜3.

  18. Modeling a bus through a sequence of traffic lights.

    PubMed

    Villalobos, Jorge; Muñoz, Víctor; Rogan, José; Zarama, Roberto; Penagos, Juan Felipe; Toledo, Benjamín; Valdivia, Juan Alejandro

    2015-07-01

    We propose a model of a bus traveling through a sequence of traffic lights, which is required to stop between the traffic signals to pick up passengers. A two dimensional model, of velocity and traveled time at each traffic light, is constructed, which shows non-trivial and chaotic behaviors for realistic city traffic parameters. We restrict the parameter values where these non-trivial and chaotic behaviors occur, by following analytically and numerically the fixed points and period 2 orbits. We define conditions where chaos may arise by determining regions in parameter space where the maximum Lyapunov exponent is positive. Chaos seems to occur as long as the ratio of the braking and accelerating capacities are greater than about ?3. PMID:26232968

  19. Baseline Testing of the Hybrid Electric Transit Bus

    NASA Technical Reports Server (NTRS)

    Brown, Jeffrey C.; Eichenberg, Dennis J.; Thompson, William K.

    1999-01-01

    A government, industry and academic cooperative has developed a Hybrid Electric Transit Bus (HETB). Goals of the program include doubling the fuel economy of city transit buses currently in service, and reducing emissions to one-tenth of EPA standards. Unique aspects of the vehicle's power system include the use of ultra-capacitors for the energy storage system and the planned use of a natural gas fueled turbogenerator, to be developed from a small jet engine. At over 17000 kg gross weight, this is the largest vehicle to use ultra-capacitor energy storage. A description of the HETB, the results of performance testing, and future vehicle development plans are the subject of this report.

  20. STS-98 crew prepares to board bus at SLF

    NASA Technical Reports Server (NTRS)

    2001-01-01

    STS-98 Mission Commander Kenneth Cockrell waves to his family at the Shuttle Landing Facility after the crew's arrival Sunday to complete preparations for launch. In the background, Mission Specialist Robert Curbeam (left) and Pilot Mark Polansky are also caught waving. The crew is preparing to board a bus for transport to the Operations and Checkout Building where the crew quarters at KSC is located. Crew members Thomas Jones and Marsha Ivins, both mission specialists, are not in plain view. STS-98 is the seventh construction flight to the International Space Station, carrying as payload the U.S. Lab Destiny, a key element in the construction of the ISS. Launch of STS-98 is scheduled for Feb. 7 at 6:11 p.m. EST.