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. A fault-tolerant safety communication model based on dual ring bus

    Microsoft Academic Search

    Dongfeng Yue; Dong Yu; Tianrong Gao; Zhenyu Yin; Yi Hu; Jinghua Bai

    2010-01-01

    To meet the transmission security requirements of CNC systems, a message safety communication model, adopting two kinds of fault tolerance algorithms based on CNC dual ring bus, was presented. The safety communication mechanism and algorithms were deeply researched, and the structure of safety message in CNC dual ring bus was proposed. And then mathematic methods were adopted to analyze the

  3. Dual Queue Approach to Improving Network Performance During Transient Congestion Episodes

    E-print Network

    Andrew, Lachlan

    network traffic [Erramilli et al., 1996]. Given that transient congestion episodes are still a problemDual Queue Approach to Improving Network Performance During Transient Congestion Episodes David A congestion[Jain, 1990], network congestion remains a real problem. The solution is not one answer, but many

  4. Scalable synchronous queues

    Microsoft Academic Search

    William N. Scherer III; Doug Lea; Michael L. Scott

    2006-01-01

    We present two new nonblocking and contention-free implementa- tions of synchronous queues, concurrent transfer channels in which producers wait for consumers just as consumers wait for producers. Our implementations extend our previous work in dual queues and dual stacks to effect very high-performance handoff. We present performance results on 16-processor SPARC and 4- processor Opteron machines. We compare our algorithms

  5. Queue Applet

    NSDL National Science Digital Library

    Shad Gilley

    An applet that shows a queue in three different views: abstract, logical and physical. The abstract view visualizes how items are inserted into the tail end of the queue and removed from the head of the queue. The logical view represents the queue as a circular structure and shows how the head and tail pointers traverse from the end of the array to the start of the array. The physical view shows how the queue items are stored in the computer memory. The abstract view is shown by default, while the other two can be shown or hidden by the user. There is also a set of instructions on how to use the applet. The applet shows well how queues work and how they are implemented. The use of three different views support learning by showing the queue structure and queue operations in various abstraction levels. The user interface is simple and easy to use but maybe the use of other colours than just grey and black could make it more pleasant to watch. For example queue items with different colours might help in following of the animation. Also, it would be useful to have a possibility to insert some random default values into the queue. Recommended as lecture aide, standalone, self-study suppliment to tutorial or lecture.

  6. 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.

  7. Scalable synchronous queues

    Microsoft Academic Search

    William N. Scherer III; Doug Lea; Michael L. Scott

    2009-01-01

    In a thread-safe concurrent queue, consumers typically wait for producers to make data available. In a synchronous queue, producers similarly wait for consumers to take the data. We present two new nonblocking, contention-free synchronous queues that achieve high performance through a form of dualism: The underlying data structure may hold both data and, symmetrically, requests. We present performance results on

  8. SNOOPy Calendar Queue

    Microsoft Academic Search

    Kah Leong Tan; Li-Jin Thng

    2000-01-01

    Discrete event simulations often require a future event list structure to manage events according to their timestamp. The choice of an efficient data structure is vital to the performance of discrete event simulations as 40% of the time may be spent on its management. A Calendar Queue (CQ) or Dynamic Calendar Queue (DCQ) are two data structures that offers O(1)

  9. Dynamic Calendar Queue

    Microsoft Academic Search

    Jongsuk Ahn; Oh Seunghyun

    1999-01-01

    Discrete event simulations need a priority queue sorting events according to their timestamp to process events in their time order. As the number of events increases, the choice of data structure for this event list can affect the simulation performance significantly. A calendar queue is a data structure popularly used in most discrete event simulators due to its O(1) time

  10. Rapid bus multiprocessor system

    SciTech Connect

    Zoccoli, M.P.; Sanderson, A.C.

    1981-11-01

    The proposed multimicroprocessor bus system combines ease of expansion, software reconfigurability, and reasonable cost. The basic design principle is a high-speed ECL bus shared by all the 16-bit processors, memories, and peripherals, such that each device has access to the bus during every processor clock cycle. Increasing system versatility and improving cost effectiveness in the implementation of multimicroprocessor system design are the goals of this bus design. 11 references.

  11. Transit-bus maintenance

    SciTech Connect

    Purdy, J.E.; Wiegmann, J.D.; Maze, T.H.; Cook, A.R.; List, G.

    1987-01-01

    The 4 papers in the report deal with the following areas; vehicle maintenance: cost relationship and estimating methodology; theory and practice of transit-bus maintenance performance measurement; bus maintenance performance indicators; historical development and current practice; and terrain effects on bus-maintenance performance.

  12. Hydrogen powered bus

    SciTech Connect

    None

    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

  13. Factors influencing bus network design

    E-print Network

    Loh, Zhen Xiang Kenneth

    2014-01-01

    Bus network design and frequency setting, the highest level subproblems in the bus planning process, have long-term impacts on bus network performance. Improving network performance not only improves the attractiveness of ...

  14. Optical bus system LIBSY

    Microsoft Academic Search

    T. Wagner

    1985-01-01

    The local area network LIBSY, a protocol transparent ring with controlled access consisting of users, computers, and peripherical devices all connected to an optical bus by the intelligent interface device LICOM is presented. The LICOM contains the interface electronics for a bus compatible adaption to the user computer. The battery-buffered coupling optronics connects the optical fiber and the computer which

  15. School Bus Safety Report.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This publication provides a summary and update of school bus-safety activities conducted by the National Highway Traffic Safety Administration (NHTSA). This report discusses Congressional mandates and NHTSA's actions to improve school-bus safety (which include programs that affect human behavior and motor-vehicle safety performance), the magnitude…

  16. Dynamics of social queues.

    PubMed

    Toyoizumi, Hiroshi; Field, Jeremy

    2014-04-01

    Queues formed by social wasps to inherit the dominant position in the nest are analyzed by using a transient quasi-birth-and-death (QBD) process. We show that the extended nest lifespan due to division of labor between queen and helpers has a big impact on nest productivity. PMID:24378647

  17. K-NET busK-NET busK-NET busK-NET bus The K-Net bus is based on the SPI bus but it allows to addressing many different turrets

    E-print Network

    Napp, Nils

    K-NET busK-NET busK-NET busK-NET bus The K-Net bus is based on the SPI bus but it allows to addressing many different turrets like the I2C bus. The K-Net is 6 a wires bus (4 for SPI wires and 2 additional wires for request and acknowledge signals) : - /CS COM (standard SPI signal) Chip select - SCK

  18. 77 FR 48592 - Bus and Bus Facilities Discretionary Program Funds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-14

    ...bus-related equipment, and transit asset management systems. The FY...and bus related equipment. FOR FURTHER INFORMATION...including 13 asset management projects. The selected...infrastructure, and equipment in a state of...

  19. 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

  20. 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).

  1. Real-Time Queues in Heavy Traffic with Earliest-Deadline-First Queue Discipline

    E-print Network

    Real-Time Queues in Heavy Traffic with Earliest-Deadline-First Queue Discipline length and server utilization, real-time queueing theory focuses on the ability of a queue discipline first (EDF) scheduling policy. This analysis decomposes the behavior of the real-time queue into two

  2. 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.

  3. 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.

  4. Augmented thermal bus

    NASA Technical Reports Server (NTRS)

    Schrage, Dean S. (inventor)

    1993-01-01

    The present invention is directed to an augmented thermal bus. In the present design a plurity 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 pump to maintain isothermality in the source.

  5. Flexible Bus Media Redundancy

    Microsoft Academic Search

    Valter Filipe Silva; Joaquim Ferreira

    This paper proposes a flexible approach to bus media redundancy in Controller Area Network (CAN) fieldbuses, both to improve the bandwidth by transmitting different traffic in different channels or to promote redundancy by transmitting the same message in more than one channel. Specifically the proposed solution is discussed in the con- text of Flexible Time-Triggered protocol over CAN (FTT- CAN)

  6. BUS [353] BUS 142 Financial Accounting (50) [BUS, ECO] (3-0)3 Hamdi Aydin [PT] (2) BUS 152 Statistics for Social Sciences (85) [BUS,ECO,PSIR] (3-0)3 Ouz Solyali (2)

    E-print Network

    Köprülü, Kahraman Güçlü

    BUS [353] BUS 142 Financial Accounting (50) [BUS, ECO] (3-0)3 Hamdi Aydin [PT] (2) BUS 152 Statistics for Social Sciences (85) [BUS,ECO,PSIR] (3-0)3 Ouz Solyali (2) BUS 222 Organization Theory (25) (3-0)3 Emin Çemebai [PT] BUS 232 Information Systems and Programming (40) [BUS,ECO] (3-0)3 Jae Choi (2) BUS

  7. Deducing Queueing From Transactional Data: The Queue Inference Engine, Revisited

    E-print Network

    Bertsimas, Dimitris J.

    Larson [1] proposed a method to statistically infer the expected transient queue length during a busy period in 0(n 5 ) solely from the n starting and stopping times of each customer's service during the busy period and ...

  8. Analysis and design of an adaptive virtual queue (AVQ) algorithm for active queue management

    Microsoft Academic Search

    Srisankar S. Kunniyur; Rayadurgam Srikant

    2001-01-01

    Virtual Queue-based marking schemes have been recently proposed for AQM (Active Queue Management) in Internet routers. We consider a particular scheme, which we call the Adaptive Virtual Queue (AVQ), and study its following properties: stability in the presence of feedback delays, its ability to maintain small queue lengths and its robustness in the presence of extremely short flows (the so-called

  9. 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 ...

  10. Bus platform of SEEL

    NASA Astrophysics Data System (ADS)

    Kuriki, K.; Nagatomo, M.; Saito, H.; Obara, H.

    1983-10-01

    A Space Energetics and Environment Laboratory (SEEL) is proposed for utilization on NASA's space station. The technological problems, environmental assessment items, possible missions, and mission requirements of the facility are listed. SEEL will have an unmanned, general purpose free platform or bust platform, whose configuration, structure, and subsystems for attitude control, propulsion, electrical power, thermal control, communications, and data management are described. The bus platform's payload accommodation is also given. SEEL will also have an unmanned maneuverable spacecraft with rendezvous-docking function and manipulator whose requirements and design and the subsystems are summarized. Finally, SEEL's preoperational, operational, and postoperational procedures are outlined.

  11. The BLUE active queue management algorithms

    Microsoft Academic Search

    Wu-chang Feng; Kang G. Shin; Dilip D. Kandlur; Debanjan Saha

    2002-01-01

    In order to stem the increasing packet loss rates causedby an exponential increase in network traffic, the IETF has beenconsidering the deployment of active queue management techniquessuch as RED [14]. While active queue management can potentiallyreduce packet loss rates in the Internet, we show that current techniquesare ineffective in preventing high loss rates. The inherentproblem with these queue management algorithms

  12. Improving School Bus Driver Performance.

    ERIC Educational Resources Information Center

    Farmer, Ernest

    This reference source is intended to assist the school bus driver training instructor in course preparation. Instructional units for program planning each contain pertinent course questions, a summary, and evaluation questions. Unit 1, "Introduction to the School Bus Driver Training Program," focuses on basic course objectives and requirements and…

  13. Data bus system development program

    NASA Technical Reports Server (NTRS)

    Harrison, J. S. J.

    1973-01-01

    Two data bus systems were designed fabricated, Data Bus System I and Data Bus System II. The technical features of the delivered hardware include the following: (1) 5 MHz selfclocking data bus; (2) bidirectional communications utilizing Manchester Code at data rates in excess of 20,000 words per second; (3) utilization of MSI COS/MOS technology (4) probability of accepting an erroneous data bit less than 1 in 10 to the 25th power (5) low power consumption (50 to 1 reduction in quiescent current over P/MOS) (6) compatibility with projected high density packaging. Three distinct types of data bus remote terminals were developed: the subsystem interface unit, the combination of an electronic interface unit and a standard interface unit-serial, and an SIU/Preprocessor.

  14. BUS DISPATCHING AT TIMED TRANSFER TRANSIT STATIONS

    E-print Network

    Dessouky, Maged

    BUS DISPATCHING AT TIMED TRANSFER TRANSIT STATIONS USING BUS TRACKING TECHNOLOGY May 26, 1999 Maged of Southern California Los Angeles, CA 90089-0193 #12;BUS DISPATCHING AT TIMED TRANSFER TRANSIT STATIONS USING Of Delay For Given Lateness Intervals For Bus Line #26 3. Summary Of Results For The Different Dispatching

  15. Bus Serialization for Reducing Power Consumption

    Microsoft Academic Search

    Naoya Hatta; Niko Demus Barli; Chitaka Iwama; Luong Dinh Hung; Daisuke Tashiro; Shuichi Sakai; Hidehiko Tanaka

    2006-01-01

    yyy Shared-bus chip multiprocessors require buses with long wires. The portion of power consumed in wires relatively increases with device scaling. In this paper, we advocate the use of bus serialization to reduce bus power consumption. Bus serialization decreases the number of wires, and increases the pitch between wires. The wider pitch decreases the coupling capacitances of wires, and consequently

  16. 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.

  17. Calendar queues: a fast 0(1) priority queue implementation for the simulation event set problem

    Microsoft Academic Search

    Randy Brown

    1988-01-01

    A new priority queue implementation for the future event set problem is described in this article. The new implementation is shown experimentally to be O(1) in queue size for the priority increment distributions recently considered by Jones in his review article. It displays hold times three times shorter than splay trees for a queue size of 10,000 events. The new

  18. Queue-Dispatch Asynchronous Systems

    E-print Network

    Geeraerts, Gilles; Raskin, Jean-François

    2012-01-01

    To make the development of efficient multi-core applications easier, libraries, such as Grand Central Dispatch, have been proposed. When using such a library, the programmer writes so-called blocks, which are chunks of codes, and dispatches them, using synchronous or asynchronous calls, to several types of waiting queues. A scheduler is then responsible for dispatching those blocks on the available cores. Blocks can synchronize via a global memory. In this paper, we propose Queue-Dispatch Asynchronous Systems as a mathematical model that faithfully formalizes the synchronization mechanisms and the behavior of the scheduler in those systems. We study in detail their relationships to classical formalisms such as pushdown systems, Petri nets, fifo systems, and counter systems. Our main technical contributions are precise worst-case complexity results for the Parikh coverability problem for several subclasses of our model.

  19. 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.

  20. Hierarchical packet fair queueing algorithms

    Microsoft Academic Search

    Jon C. R. Bennett; Hui Zhang

    1997-01-01

    In this paper, we propose to use the idealized HierarchicalGeneralized Processor Sharing (H-GPS) model to simultaneouslysupport guaranteed real-time, rate-adaptivebest-effort, and controlled link-sharing services. We designHierarchical Packet Fair Queueing (H-PFQ) algorithms toapproximate H-GPS by using one-level variable-rate PFQservers as basic building blocks. By computing the systemvirtual time and per packet virtual start\\/finish times in unitof bits instead of seconds, most of

  1. MQSN -Fluid queues Werner Scheinhardt

    E-print Network

    Boucherie, Richard J.

    fluid. Example: Q1 = -2 2 1 -1 , Q2 = -2 2 3 -3 , and r1 = (1, 0) and r2 = (2, 0). #12;Burst(t) = exp((Q + R)t)f(0). Observe that fi(0) is 1 if i = j and 0 otherwise. #12;Burst-level models: MarkovMQSN - Fluid queues Werner Scheinhardt (with thanks to Michel Mandjes) Utrecht, fall 2014 #12;Burst

  2. 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 ...

  3. Multi-purpose satellite bus

    NASA Technical Reports Server (NTRS)

    Sakoda, Daniel; Agrawal, Brij N.

    1991-01-01

    The Multi-Purpose Satellite bus (MPS) can be used for a number of payloads which may require different orbits, pointing accuracy, and electrical power consumption. Specifically, it was designed to accommodate the Advanced Very High Resolution Radiometer and an EHF communication payload, both of which have a three-year life. The estimated beginning-of-life weight of the MPS bus is 150 kg. It can be launched by either the Pegasus ALV or the Taurus SSLV. Configuration requirements for the different missions are discussed.

  4. Entropy maximisation and queueing network models

    Microsoft Academic Search

    Demetres D. Kouvatsos

    1994-01-01

    Over recent years it has become increasingly evident that “classical” queueing theory cannot easily handle complex queueing systems and networks with many interacting elements. As a consequence, alternative ideas and tools, analogous to those applied in the field of Statistical Mechanics, have been proposed in the literature. In this context, the principles of Maximum Entropy (ME) and Minimum Relative Entropy

  5. Model Predictive Control for the Acquisition Queue

    E-print Network

    Nazarathy, Yoni

    state and control (X(·), U(·)) are continuous in value Find a reference trajectory Apply "standard" control-theoretic methods for tracking the reference trajectory Use Model Predictive Control (MPC) usingModel Predictive Control for the Acquisition Queue and Related Queueing Networks Johan van

  6. Queueing network analysis: concepts, terminology, and methods

    Microsoft Academic Search

    Rusty O. Baldwin; Nathaniel J. Davis Iv; Scott F. Midkiff; John E. Kobza

    2003-01-01

    Queueing network analysis can be a valuable tool to analyze network models. However, the vast number and diverse nature of the tools available to analyze a problem can often leave the uninitiated frustrated or bewildered--awash in concepts, terminology, and methods not encountered elsewhere. As a primer for queueing network analysis, this paper emphasizes essential concepts and terminology. Selection of analytical

  7. An integrated approach for interoperation between heterogeneous bus networks in city bus control system

    Microsoft Academic Search

    Xu Jun; Li Gangyan

    2009-01-01

    An integrated approach for interoperation between heterogeneous bus networks in city bus control system is proposed to increase the interoperability and the degree of information integration of the system. As the demand and complexity of the city bus control system has increased, communication protocols as LIN and CAN (high-speed and low-speed) and have been applied, resulting in several heterogeneous bus

  8. ROBUST FEEDBACK CONTROL OF A SINGLE SERVER QUEUEING SYSTEM

    Microsoft Academic Search

    JOSEPH A. BALL; MARTIN V. DAY; PUSHKIN KACHROO

    1998-01-01

    This paper extends previous work of Ball-Day-Kachroo (2) to con- trol of a model of a simple queueing server. There are n queues of customers to be served by a server who can service only one queue at a time. Each queue is subject to a unknown arrival rate, called a \\\\disturbance\\

  9. Conservation equations and variance reduction in queueing simulations

    Microsoft Academic Search

    John S. Carson; Averill M. Law

    1977-01-01

    We consider the efficient estimation of mean delay in queue, d, mean wait in system, w, time average number in queue, Q, and time average number in system, L, for simulated queueing systems. We prove for the GI\\/G\\/s queue that it is more efficient to estimate w, Q, and L from an estimate of d than it is to estimate

  10. 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.

  11. School Bus Alert System Reduces Delays.

    ERIC Educational Resources Information Center

    Pleasnick, Stephen G.

    1985-01-01

    The school bus alert monitor is a computerized school bus alert and warning sytem that notifies parents of school bus arrival via radio frequency technology. The system also has been shown to enhance the self esteem of disabled transportation users. (CL)

  12. Data Bus Adapts to Changing Traffic Level

    NASA Technical Reports Server (NTRS)

    Lew, Eugene; Deruiter, John; Varga, Mike

    1987-01-01

    Access becomes timed when collisions threaten. Two-mode scheme used to grant terminals access to data bus. Causes bus to alternate between random accessibility and controlled accessibility to optimize performance and adapt to changing data-traffic conditions. Bus is part of 100-Mb/s optical-fiber packet data system.

  13. 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.

  14. Tacoma gets the early bus

    Microsoft Academic Search

    1991-01-01

    What happened, then, when Tacoma, Washington and Seattle each set about choosing an alternative bus fuel in the interests of clean air Not what you'd think. In a major role reversal, Seattle got headaches, while Tacoma got the distinction of being a national pioneer. That's because it was Tacoma that chose natural gas. Ron Shipley is director of maintenance for

  15. Synchronizing Data-Bus Messages

    NASA Technical Reports Server (NTRS)

    Harris, L. H.

    1985-01-01

    Adapter allows communications among as many as 30 data processors without central bus controller. Adapter improves reliability of multiprocessor system by eliminating point of failure that causes entire system to fail. Scheme prevents data collisions and eliminates nonessential polling, thereby reducing power consumption.

  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. A new vehicle data bus architecture and IVIS evaluation platform for ITS modulus

    SciTech Connect

    Spelt, P.F. [Oak Ridge National Lab., TN (United States); Kirson, A.M. [Motorola, Inc., Northbrook, IL (United States); Scott, S. [Jet Propulsion Lab., Washington, DC (United States)

    1998-12-31

    An increasing number of ITS-related after-market systems present a set of in-vehicle installation and use problems relatively unique in the history of automobile use. Many automobile manufacturers would like to offer these new state of the art devices to customers, but are hampered by the current design cycle of new cars. While auto manufacturers are indeed using multiplex buses (the automotive equivalent of a computer local area network), problems remain because manufacturers are not converging on a single bus standard. This paper presents a new dual-bus architecture to address these problems, with an In-Vehicle Information System (IVIS) research platform on which the principles embodied in the ITS Data Bus architecture can be evaluated. The dual-bus architecture has been embodied in a proposed SAE standard, with a ratification vote in December, 1996. The architecture and a reference model for the interfaces and protocols of the new bus are presented and described. The goals of the ITS Data Bus are to be inexpensive and easy to install, and to provide for safe and secure functioning. These high-level goals are embodied in the proposed standard. The IVIS Development Platform comprises a number of personal computers linked via ethernet LAN, with a high-end PC serving as the IVIS computer. In this LAN, actual devices can be inserted in place of the original PC which emulated them. This platform will serve as the development and test bed for an ITS Data Bus Conformity Test, the SAE standard for which has also been developed.

  18. 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 ...

  19. A Framework for Alternate Queueing: Towards Traffic Management by P C-UNIX Based Routers

    Microsoft Academic Search

    Kenjiro Cho

    1998-01-01

    Queueing is an essential element of traffic manage- ment, but the only queueing discipline used in traditional UNIX systems is simple FIFO queueing. This paper de- scribes ALTQ, a queueing framework that allows the use of a set of queueing disciplines. We investigate the is- sues involved in designing a generic queueing framework as well as the issues involved in

  20. Optimal queue length for orthopaedic surgery with surgeon-specific queues and maximum waiting time

    Microsoft Academic Search

    Antti Peltokorpi; Juha-Matti Lehtonen; Paulus Torkki; Teemu Moilanen

    Lengthened waiting times to surgical operations lead to a diminished patient satisfaction, deteriorated medical quality and increased costs. In order to avoid long queues, authorities have enacted care guarantees that define the maximum waiting time to services. In this study, the effect of queue length and care guarantee of maximum waiting time on OR productivity is discussed from a case

  1. Effects of the Bus Regulatory Reform Act of 1982 on the Texas intercity bus industry 

    E-print Network

    Kuenzer, Karen Elizabeth

    1993-01-01

    EFFECTS OF THE BUS REGULATORY REFORM ACT OF 1982 ON THE TEXAS INTERCITY BUS INDUSTRY A Thesis by KAREN ELIZABETH KUENZER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 1993 Major Subject: Civil Engineering EFFECTS OF THE BUS REGULATORY REFORM ACT OF 1982 ON THE TEXAS INTERCITY BUS INDUSTRY A Thesis by KAREN ELIZABETH KUENZER Submitted to the Office of Graduate Studies...

  2. Performance and reliability of Multistage Bus Network

    E-print Network

    Askar, Tahsin

    1993-01-01

    at each queueing center. System response time and processor utilization are considered as the measures of the performance. It is concluded that the performance of an MBN is better than the performance of a MIN when cluster requests are treated...

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

    E-print Network

    Kim, Wonho

    2005-02-17

    networks with nearside bus stop because of the uncertainty in dwell time. Unfortunately, most bus stops on arterial roadways are of this type in the U.S. This dissertation showed that dwell time at nearside bus stops could be modeled using weighted least...

  4. Dynamic Simulation Control with Queue Visualization Saurabh Mittal

    E-print Network

    Dynamic Simulation Control with Queue Visualization Saurabh Mittal Bernard P. Zeigler Arizona Center of Integrative Modeling and Simulation (ACIMS) ECE Department, University of Arizona Tucson, AZ and simulation environment with dynamic simulation control and queue visualization. The development

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

    E-print Network

    Cai, Yi

    2012-02-14

    This thesis explores the queueing performance of a wireless communication system that transmits packets over a correlated erasure channel using the IEEE 802.11 protocol suit. The channel states and the queue length together form a Markov chain...

  6. Extreme Value Theory for Queues Via Cycle Maxima

    Microsoft Academic Search

    Søren Asmussen

    1998-01-01

    The present state of extreme value theory for queues is surveyed. The exposition focuses on the regenerative properties of queueing systems, which reduces the problem to the study of the tail of the maximum \\u000a

  7. 49 CFR 605.19 - Approval of school bus operations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Approval of school bus operations. 605.19 Section 605.19...TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.19 Approval of...

  8. 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...TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.19 Approval of...

  9. On Asymptotic Optimality of Dual Scheduling Algorithm In A Generalized Switch

    Microsoft Academic Search

    Lijun Chen; Steven H. Low; John C. Doyle

    2006-01-01

    Generalized switch is a model of a queueing system where parallel servers are interdependent and have time-varying service capabilities. This paper considers the dual scheduling algorithm that uses rate control and queue-length based scheduling to allocate resources for a generalized switch. We consider a saturated system in which each user has in£nite amount of data to be served. We prove

  10. MRE Hierarchical Decomposition of General Queueing Network Models

    Microsoft Academic Search

    Panagiotis J. Tomaras; Demetres D. Kouvatsos

    1991-01-01

    Summary The principle of Minimum Relative Entropy (MRE), given fully decomposable subset and aggregate mean queue length, utilisation and flow-balance constraints, is used in conjunction with asymptotic connections to infinite capacity queues, to derive new analytic approximations for the conditional and marginal state probabilities of single class general closed queueing network models (QNMs) in the context of a multilevel variable

  11. Queue Management in Network Processors I. Papaefstathiou1

    E-print Network

    Paris-Sud XI, Université de

    the requirements for hardware assisted memory management in order to achieve wire-speed operation at gigabit per as packet queues in the processor packet buffer [1]. Therefore, effective queue management is a key to high; then we briefly present an FPGA-based queue management system, which can scale efficiently and provide

  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 (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

  13. Threshold queueing describes the fundamental diagram of uninterrupted traffic

    E-print Network

    Boucherie, Richard J.

    Threshold queueing describes the fundamental diagram of uninterrupted traffic Niek Baer, Richard J and a novel threshold queue that captures the main aspects of the empiri- cal shape of the fundamental diagram of the fundamental diagram. Keywords: Threshold queue, Hysteresis, Capacity drop, Fundamental diagram, Matrix

  14. 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.

  15. ORION II bus demonstration. Demonstration report (Final)

    Microsoft Academic Search

    Shanley

    1989-01-01

    The Central New York Regional Transportation Authority conducted an 18-month demonstration to determine how the ORION II bus operates in actual service. The ORION II vehicle is a small low floor, accessible heavy duty, diesel-powered transit bus designed to meet the needs of the elderly and handicapped. It has the capacity to seat 26 passengers with 4 wheelchair lockdowns. Side

  16. Motherboard testing using the PCI bus

    Microsoft Academic Search

    David Mcclintock; Lance Cunningham; Takis Petropoulos

    2000-01-01

    Reevaluating the traditional testing methods and exploiting the versatility of today's computer architectures can realize a dramatically different approach to computer motherboard testing. The PCI bus, and its incorporation into modern personal computers, provides the technology for realizing a revolutionary, new method of motherboard testing. Functional testing through the motherboard's PCI bus provides a tool for greater flexibility and an

  17. 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…

  18. A bus router for IC layout

    Microsoft Academic Search

    Margaret Lie; Chi-Song Horng

    1982-01-01

    This paper describes a bus router that is part of a custom IC mask layout system called CIPAR. CIPAR works with rectangular building blocks of arbitrary dimensions. The router is designed specifically to handle power and ground buses. It can route these nets completely on one metal layer. The router also automatically calculates and tapers the bus path width based

  19. Comparison of load-based and queue-based active queue management algorithms

    NASA Astrophysics Data System (ADS)

    Kwon, Minseok; Fahmy, Sonia

    2002-07-01

    A number of active queue management algorithms have been studied since Random Early Detection (RED) was first introduced in 1993. While analytical and experimental studies have debated whether dropping/marking should be based on average or instantaneous queue length or, alternatively, based on input and output rates (or queue length slope), the merits and drawbacks of the proposed algorithms, and the effect of load-based versus queue-based control have not been adequately examined. In particular, only RED has been tested in realistic configurations and in terms of user metrics, such as response times and average delays. In this paper, we examine active queue management (AQM) that uses both load and queuing delay to determine its packet drop/mark probabilities. This class of algorithms, which we call load/delay controllers (LDC), has the advantage of controlling the queuing delay as well as accurately anticipating incipient congestion. We compare LDC to a number of well-known active queue management algorithms including RED, BLUE, FRED, SRED, and REM in configurations with multiple bottlenecks, round trip times and bursty Web traffic. We evaluate each algorithm in terms of Web response time, delay, packet loss, and throughput, in addition to examining algorithm complexity and ease of configuration. Our results demonstrate that load information, along with queue length, can aid in making more accurate packet drop/mark decisions that reduce the Web response time.

  20. Optical Fiber Bus Protection Network to Multiplex Sensors: Amplification by Remotely Pumped EDFAs

    Microsoft Academic Search

    Oscar García López; Kevin Schires; Paul Urquhart; Nicolas Gueyne; BÉatrice Duhamel

    2009-01-01

    We report a physical-layer study of an optical fiber network for the multiplexing of sensors that can regain service after damage to its fibers. It is a symmetrical dual-fiber bus that uses ldquodedicated-linerdquo or ldquodedicated-pathrdquo protection switching in response to a failure. Amplification is normally needed when serving more than ~ 10 sensors, even when the network's directional couplers are

  1. Task Release Control for Decision Making Queues

    E-print Network

    Srivastava, Vaibhav; Bullo, Francesco; Langbort, Cédric

    2010-01-01

    We consider the optimal duration allocation in a decision making queue. Decision making tasks arrive at a given rate to a human operator. The correctness of the decision made by human evolves as a sigmoidal function of the duration allocated to the task. Each task in the queue loses its value continuously. We elucidate on this trade-off and determine optimal policies for the human operator. We show the optimal policy requires the human to drop some tasks. We present a receding horizon optimization strategy, and compare it with the greedy policy.

  2. Representing Workloads in GI\\/G\\/1 Queues Through the Preemptive-Resume LIFO Queue Discipline

    Microsoft Academic Search

    Shun-chen Niu

    1988-01-01

    Abstract We give in this paper a detailed sample-average analysis of GI\\/G\\/1 queues with the preemptive-resume LIFO (last-in-first-out) queue discipline: We study the long-run “state” behavior of the system by averaging over arrival epochs, departure epochs, as well as time, and obtain relations that express the resulting averages in terms of basic characteristics within busy cycles. These relations, together with

  3. 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.

  4. Review of Shuttle Bus Operations The President's Advisory Committee

    E-print Network

    Thompson, Michael

    Review of Shuttle Bus Operations Report of The President's Advisory Committee on Transportation and Parking (PACT&P) August 30, 2005 #12;August 30, 2005 Review of Shuttle Bus Operations McMaster University A .......................................................................................... 19 #12;August 30, 2005 Review of Shuttle Bus Operations McMaster University 3 Review of Shuttle Bus

  5. A real time budgeting method for module-level-pipelined bus based system using bus scenarios

    Microsoft Academic Search

    Tadaaki Tanimoto; Seiji Yamaguchi; Akio Nakata; Teruo Higashino

    2006-01-01

    Abstract In designing bus based systems with parallel and pipelined architecture, it is important to derive a real time budget (a specified execution time limit) for each task of a bus based system while satisfying given end-to-end real-time constraints of the entire system such as throughput and latency constraints. In this paper, we define a bus scenario representing a set

  6. Perfect simulation, monotonicity and finite queueing networks

    E-print Network

    Paris-Sud XI, Université de

    Perfect simulation, monotonicity and finite queueing networks Jean-Marc Vincent LIG Laboratory. Simulation approaches are alternative methods to estimate quality of service of such networks. Based on discrete event simulation [4] or on Markov properties (MCMC methods) [9], simulations estimate the steady

  7. APPLICATIONS OF SINGULAR PERTURBATION METHODS IN QUEUEING

    Microsoft Academic Search

    Charles Knessl; Charles Tier

    A survey is presented describing the application of singular perturbation techniques to queueingsystems. Thegoalisto computeperformancemeasuresbyconstructingapproximate solutions to specific problems involving either the Kolmogorov forward or backward equation which contain a small parameter. These techniques are particularly useful on problems for which exact solutions are not available. Four different classes of problems are surveyed: (i) state-dependent queues; (ii) systems with a

  8. 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

  9. 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...

  10. Your GreeterARRIVAL BUS LAYOVER

    E-print Network

    not unload or load buses until directed to do so. Please do not unload or load buses on Central Park West to park the bus + go over Museum conduct with your group + assist unloading your group + arrange for lunch

  11. Your GreeterARRIVAL BUS LAYOVER

    E-print Network

    not unload or load buses until directed to do so. Please do not unload or load buses on Central Park West for the driver to park the bus + go over Museum conduct with your group + assist unloading your group + arrange

  12. MEMORY SYSTEM DESIGN FOR BUS BASED MULTIPROCESSORS

    E-print Network

    Sohi, Guri S.

    #12;MEMORY SYSTEM DESIGN FOR BUS BASED MULTIPROCESSORS by Men-Chow Chiang A thesis submitted) at the UNIVERSITY OF WISCONSIN -- MADISON 1991 #12;Chapter 1 Introduction 1.1. Motivation for this Dissertation Low

  13. MEMORY SYSTEM DESIGN FOR BUS BASED MULTIPROCESSORS

    E-print Network

    Sohi, Guri S.

    #12; MEMORY SYSTEM DESIGN FOR BUS BASED MULTIPROCESSORS by Men­Chow Chiang A thesis submitted) at the UNIVERSITY OF WISCONSIN ­­ MADISON 1991 #12; Chapter 1 Introduction 1.1. Motivation for this Dissertation Low

  14. TMS communications software. Volume 2: Bus interface unit

    NASA Technical Reports Server (NTRS)

    Gregor, P. J.

    1979-01-01

    A data bus communication system to support the space shuttle's Trend Monitoring System (TMS) and to provide a basis for evaluation of the bus concept is described. Installation of the system included developing both hardware and software interfaces between the bus and the specific TMS computers and terminals. The software written for the microprocessor-based bus interface units is described. The software implements both the general bus communications protocol and also the specific interface protocols for the TMS computers and terminals.

  15. Development of process bus for busbar protection

    Microsoft Academic Search

    Yasuyuki Tanaka; Kiyosumi Ideta; Shigeto Oda; Keigo Adachi; Hideo Noguchi

    2011-01-01

    Busbar protection is described for a bus with current inputs for up to 32 bays. For busbar protection with IEDs and MUs using IEC61850-9-2 process bus, communication traffic jams are the main concern, due to transferring 80 samples\\/cycle data from all bay MUs to IED via 100BASE-FX. This paper describes peer-to-peer connection between MUs and IED in order to segrigate

  16. 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.

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

    E-print Network

    Cheek, Marshall Tyler

    2007-09-17

    length to produce a current estimate of queue length. The implementation of this method required some effort to calibrate, and produced a bias that inherently estimated queue lengths lower than baseline (actual) queue lengths. It was the researcher...

  18. Control of a heterogeneous two-server exponential queueing system

    NASA Technical Reports Server (NTRS)

    Larsen, R. L.; Agrawala, A. K.

    1983-01-01

    A dynamic control policy known as 'threshold queueing' is defined for scheduling customers from a Poisson source on a set of two exponential servers with dissimilar service rates. The slower server is invoked in response to instantaneous system loading as measured by the length of the queue of waiting customers. In a threshold queueing policy, a specific queue length is identified as a 'threshold,' beyond which the slower server is invoked. The slower server remains busy until it completes service on a customer and the queue length is less than its invocation threshold. Markov chain analysis is employed to analyze the performance of the threshold queueing policy and to develop optimality criteria. It is shown that probabilistic control is suboptimal to minimize the mean number of customers in the system. An approximation to the optimum policy is analyzed which is computationally simple and suffices for most operational applications.

  19. Page 264 Courses: Business Administration (BUS) Sonoma State University 2012-2013 Catalog Business Administration (BUS)

    E-print Network

    Ravikumar, B.

    to introduce students to the range of perspectives available in the discipline. Topics will include: accounting and pre-business math requirement. BUS 219 e/U compUting toolS for BUS (3) A laboratory-intensive course in which students gain a working knowledge of personal and mainframe computer operating systems as well

  20. Courses: Business Administration (BUS) Page 263Sonoma State University 2011-2012 Catalog Business Administration (BUS)

    E-print Network

    Ravikumar, B.

    to introduce students to the range of perspectives available in the discipline. Topics will include: accounting- tency and pre-business math requirement. buS 219 e/u COMputinG tOOlS fOr buS (3) A laboratory-intensive course in which students gain a working knowledge of personal and mainframe computer operating systems

  1. Global Bus Design of a Bus-Based COMA Multiprocessor DICE

    E-print Network

    Cho, Sangyeun

    Global Bus Design of a Bus-Based COMA Multiprocessor DICE Gyungho Lee, Bland Quattlebaum, Sangyeun based on a dis- tributed shared-memory architecture, known as Cache-Only Memory Architecture (COMA). Unlike previous COMA pro- posals for large-scale multiprocessing, DICE utilizes the COMA to effectively

  2. Effects of the Bus Regulatory Reform Act of 1982 on the Texas intercity bus industry

    E-print Network

    Kuenzer, Karen Elizabeth

    1993-01-01

    . The passage of the Bus Regulatory Reform Act of 1982 was an effort to decrease operating costs and increase ridership by allowing bus companies to discontinue unprofitable routes, have freedom over the setting of fares, and enter into new, competitive markets...

  3. School Bus and School Pupil Activity Bus Inspection and Maintenance Guide.

    ERIC Educational Resources Information Center

    Sowash, Fred W.

    This publication deals with suggested maintenance standards that apply to vehicles used for pupil transportation in California and covers all the safety-related systems that are common to most buses. The guide has been prepared to help all school bus and school pupil activity bus operators set up an inspection and preventive maintenance program…

  4. Maximum Entropy and the G\\/G\\/1\\/N Queue

    Microsoft Academic Search

    Demetres D. Kouvatsos

    1986-01-01

    A new “hybrid” analytic framework, based on the principle of maximum entropy, is used to derive a closed form expression for the queue length distribution of a G\\/G\\/1 finite capacity queue. It is shown that “Birth-Death” homogeneous recursions for a single resource queue are special cases of maximum entropy “one-step” transitions which can be applied either in an operational or

  5. Simple spectral Representations for the M\\/M\\/1 Queue

    Microsoft Academic Search

    Joseph Abate; Ward Whitt

    1988-01-01

    This paper shows that certain basic descriptions of the time-dependent behavior of the M\\/M\\/1 queue have very simple representations as mixtures of exponentials. In particular, this is true for the busy-period density, the probability that the server is busy starting at zero, the expected queue length starting at zero and the autocorrelation function of the stationary queue-length process. In each

  6. Maximum Entropy Analysis of Queueing Network Models

    Microsoft Academic Search

    Demetres D. Kouvatsos

    1993-01-01

    The principle of Maximum Entropy (ME) provides a consistent method of inference for estimating the form of an unknown discrete-state probability distribution, based on information expressed in terms of true expected values. In this tutorial paper entropy maximisation is used to characterise product-form approximations and resolution algorithms for arbitrary continuous-time and discrete-time Queueing Network Models (QNMs) at equilibrium under Repetitive-Service

  7. 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…

  8. 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.

  9. Factors affecting the probability of bus drivers being at-fault in bus-involved accidents.

    PubMed

    Goh, Kelvin; Currie, Graham; Sarvi, Majid; Logan, David

    2014-05-01

    Previous research has provided little insight into factors that influence the probability of bus drivers being at-fault in bus-involved accidents. In this study, an analysis was conducted on accident data compiled by a bus company that include an assessment on whether the bus driver was deemed by the company to hold primary responsibility for accident occurrence. Using a mixed logit modelling approach, roadway/environmental, vehicle and driver related variables that were identified to be influential were road type, speed limit, traffic/lighting conditions, bus priority, bus age/length and driver's age/gender/experience/historic at-fault accident record. Results were indicative of possible confined road-space issues that bus drivers face along routes with roadside traffic friction and point to the provision of exclusive right of way for buses as a possible way to address this. Results also suggest benefits in assigning routes comprising mainly divided roads as well as newer and shorter buses to less experienced drivers. PMID:24486771

  10. Design of multi-mission spacecraft bus

    NASA Technical Reports Server (NTRS)

    Agrawal, Brij N.

    1992-01-01

    This paper presents preliminary design of a multimission spacecraft bus for meteorological and communications payloads. The meteorological payload uses sun-synchronous circular orbit and the communications payload uses Molniya type orbit to provide communications for areas not covered by geosynchronous communications satellites. The launch vehicles are Pegasus for the meteorological payload and Taurus for the communications payload. The spacecraft bus uses three-axis stabilization consisting of a three reaction wheel system. The electric power system consists of single-axis tracking silicon solar array and Ni2 H2 batteries. The propulsion subsystem consists of six hydrazine thrusters and one propellant tank.

  11. 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.

  12. 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 ...

  13. Research of intelligent dual - line lubricant system based on PROFIBUS

    Microsoft Academic Search

    Yin Zhang; Xiangdong Kong; Chao Ai

    2010-01-01

    In this paper a new intelligent dual-line lubricant bus system was introduced. SIEMENS PLC is central controller, the PROFIBUS is the communication mode, the touch screen is to show the working status data and set data can be input through it in this system. Through measuring the oil temperature, oil pressure, and pressure difference etc signals, the system can automatically

  14. Research on 1Wire Bus Temperature Monitoring System

    Microsoft Academic Search

    Wang Jingzhuo; Gong Chenglong

    2007-01-01

    Based on 1-Wire bus technology, the 1-Wire bus temperature monitoring MicroLan was designed through using computer serial communication port, protocol transform chip DS2480 and 1-Wire bus digital temperature sensor DS18B20. The structure, character, ROM command, function command of DS18B20 and operating principle of DS2480B were analyzed. Consequently, the interface circuit between 1-Wrie bus and COM port is provided. At the

  15. 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.

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

    SciTech Connect

    Marr, W.W.; Sekar, R.R. [Argonne National Lab., IL (United States); Ahlheim, M.C. [Regional Transportation Authority, Chicago, IL (United States)

    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.

  17. Improving multirobot, cooperative search via local target queues

    Microsoft Academic Search

    Monica Anderson; Nikolaos Papanikolopoulos

    2007-01-01

    Multirobot coordination techniques range from sharing state and intent information to explicit coordination strategies. The choice of cooperation strategy can affect task performance and resource utilization. This paper investigates the use of local search queues, rather than globally shared search queues. This work shows this change improves search in terms of interference and communications loads, two key factors in multirobot

  18. Managing network congestion with a Kohonen-based RED queue

    E-print Network

    Paris-Sud XI, Université de

    Managing network congestion with a Kohonen-based RED queue Emmanuel Lochin Universit´e de Toulouse length. These AQM are mostly improvements of the Random Early Detection (RED) model. Unfortunately Kohonen-RED (KRED), enables a stable queue length without complex parameters setting and passive

  19. Queueing Systems Large Deviations and the Generalized Processor

    E-print Network

    Zhang, Zhi-Li

    introduced by the GPS scheduling discipline makes understanding of its behavior a challenging task (GPS) scheduling discipline. In the special case where there are only two queues, the upper and lower­queue GPS system is captured using the notion of partial feasi­ ble sets, and the bounds are obtained using

  20. 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 in the appointment planning process. This paper considers the Geox /D/1 queue with slot reservations that serves regular patients and priority patients. Prior- ity patients reserve a time slot in a reservation window

  1. BLUE: A New Class of Active Queue Management Algorithms

    Microsoft Academic Search

    Wu-chang Feng; Dilip D. Kandlur; Debanjan Saha; Kang G. Shin

    1999-01-01

    In order to stem the increasing packet loss rates caused by an exponential increase in network traffic, the IETF is considering the deployment of active queue management techniques such as RED (13). While active queue management can potentially reduce packet loss rates in the Internet, this paper shows that current techniques are ineffective in preventing high loss rates. The inherent

  2. Equilibrium properties of the M\\/G \\/1 queue

    Microsoft Academic Search

    Søren Asmussen

    1981-01-01

    Various aspects of the equilibrium M\\/G\\/1 queue at large values are studied subject to a condition on the service time distribution closely related to the tail to decrease exponentially fast. A simple case considered is the supplementary variables (age and residual life of the current service period), the distribution of which conditioned upon queue length n is shown to have

  3. A Singular Perturbation Approach to Analysing a RED queue

    Microsoft Academic Search

    Eitan Altman; K. Avrachenkov; B. J. Prabhu

    Several Active Queue Management (AQM) techniques for routers in the Internet have been proposed and studied during the past few years. One of the widely studied proposals, Random Early Detection (RED), involves dropping an incoming packet with some probability based on the estimated average queue length at the router. The analytical approaches to obtaining average drop probabilities in a RED

  4. Attention Allocation for Decision Making Queues$ Vaibhav Srivastavaa

    E-print Network

    Bullo, Francesco

    involving human decision making, visual perception, human-machine communication and advertising response that is incorporated as a latency penalty. We investigate the trade-off between the reward obtained by processing guidelines for the design of such queues. Keywords: sigmoid utility, human decision making, control of queues

  5. From Tokyo station 1. By Train and Local Bus (or Taxi)

    E-print Network

    Fukai, Tomoki

    From Tokyo station 1. By Train and Local Bus (or Taxi) JR Joban line Tokyo Station (JR Yamanote, Terminal 2; No.10 Bus Stop) Tsukuba Center 60 min. 2,540 yen [Caution] You have to buy bus ticket at Ticket [Caution]You have to buy bus ticket at Ticket Counter. Community Bus "TsukuBus" N-Shuttle Tsukuba Center

  6. Modeling Transit Trip Time Using Archived Bus Dispatch System Data

    E-print Network

    Bertini, Robert L.

    Modeling Transit Trip Time Using Archived Bus Dispatch System Data Robert L. Bertini1 and Ahmed M. TriMet has implemented a Bus Dispatch System BDS as a part of its overall service control studied. Data TriMet implemented a Bus Dispatch System BDS as a part of its overall operation

  7. Information management advanced development. Volume 3: Digital data bus breadboard

    NASA Technical Reports Server (NTRS)

    Gerber, C. R.

    1972-01-01

    The design, development, and evaluation of the digital data bus breadboard for the modular space station are discussed. Subjects presented are: (1) requirements summary, (2) parametric data for bus design, (3) redundancy concepts, and (4) data bus breadboard performance and interface requirements.

  8. Assessing Bus Transport Reliability Using MicroSimulation

    Microsoft Academic Search

    José Ap. Sorratini; Ronghui Liu; Shalini Sinha

    2008-01-01

    A wide range of public transport schemes have been proposed and put in practice to improve bus service reliability (including bus lanes, bus priority signals, passenger information systems, etc.). Central to the successful evaluation of such operational and management measures is to have reliability indicators which are easy to measure and can be used readily by operators to identify unreliable

  9. Active Queue Management (AQM)Active Queue Management (AQM) Need for AQMNeed for AQM

    E-print Network

    Yeom, Ikjun

    of data in burst. · Random drop or drop front solves the lock-out problem. · Active queue management of AQMAdvantages of AQM · Reduce number of packets dropped in routers ­ Permit packets in burst ­ Avoid global. Utilization Q. Delay Drop rate0p Utilization #12;7 Random Early DetectionRandom Early Detection · An active

  10. Maximum Entropy Two-Station Cyclic Queues with Multiple General Servers

    Microsoft Academic Search

    Demetres D. Kouvatsos; John Almond

    1988-01-01

    The efficient implementation and extension of various approximate methods for general queueing networks require the study of two-station cyclic queues. In this paper maximum entropy formalism is used to analyse two-station cyclic queues with multiple general servers and a fixed number of jobs. New robust “one step” recursions for the queue length distribution are derived and asymptotic connections to infinite

  11. Measuring queue capacities of IEEE 802.11 wireless access points

    Microsoft Academic Search

    Feng Li; Mingzhe Li; Rui Lu; Huahui Wu; Mark Claypool; Robert E. Kinicki

    2007-01-01

    While queue capacities have a direct impact on loss and latency during congestion, and wireless networks continue to spread in university, corporate and home networks, little is publicly known about the queue capacities of wireless access points (APs). This paper presents and deploys the Access Point Queue (APQ) methodology for externally estimating the queue capacity for a wireless AP. APQ

  12. Dual Instantons

    NASA Astrophysics Data System (ADS)

    Pinzul, A.; Stern, A.

    2000-08-01

    We show how to map the Belavin-Polyakov instantons of the O\\(3\\)-nonlinear ? model to a dual theory where they then appear as nontopological solitons. They are stationary points of the Euclidean action in the dual theory, and moreover, the dual action and the O\\(3\\)-nonlinear ? model action agree on shell.

  13. 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...

  14. Main Entrances Free City Bus Stops

    E-print Network

    Magee, Derek

    (permit holders only)P Visitor car parking only. Visitors must display a visitor parking permit)P Visitor car parking only. Visitors must display a visitor parking permit in their car, which they can B Main Entrances Free City Bus Stops Controlled parking areas (permit holders only)P Visitor car

  15. 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.

  16. Improving bus rollover design through modal analysis

    Microsoft Academic Search

    Aleksandar Subic; Jimin He

    1997-01-01

    Improvement of vehicle stability and crashworthiness to reduce rollover and to provide increased occupant protection in the event of rollover requires that the effects of design parameters on vehicle rollover propensity are thoroughly understood. Improvement of rollover characteristics of buses currently requires extensive experimentation and considerable resources associated with rollover destruction of experimental bus structures. There is an unmet need

  17. Modeling Crosstalk Effects in CNT Bus Architectures

    Microsoft Academic Search

    Daniele Rossi; José Manuel Cazeaux; Cecilia Metra; Fabrizio Lombardi

    2007-01-01

    Carbon nanotubes (CNTs) have been widely proposed as interconnect fabric for nano and very deep submicron (silicon-based) technologies due to their robustness to electromigration. In this paper, issues associated with crosstalk among bus lines implemented by CNTs are investigated in detail. CNT-based interconnects are modeled and the effects of crosstalk on performance and correct operation are evaluated by simulation. Existing

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

    SciTech Connect

    Truett, L.F.; Moore, S.; Tonn, B. [Oak Ridge National Lab., TN (United States); Conley, T. [GTE Wireless, Nashville, TN (United States)

    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.

  19. Queueing Phase Transition: Theory of Translation

    NASA Astrophysics Data System (ADS)

    Romano, M. Carmen; Thiel, Marco; Stansfield, Ian; Grebogi, Celso

    2009-05-01

    We study the current of particles on a lattice, where to each site a different hopping probability has been associated and the particles can move only in one direction. We show that the queueing of the particles behind a slow site can lead to a first-order phase transition, and derive analytical expressions for the configuration of slow sites for this to happen. We apply this stochastic model to describe the translation of mRNAs. We show that the first-order phase transition, uncovered in this work, is the process responsible for the classification of the proteins having different biological functions.

  20. Queue-length synchronization in communication networks

    NASA Astrophysics Data System (ADS)

    Mukherjee, Satyam; Gupte, Neelima

    2009-05-01

    We study the synchronization in the context of network traffic on a 2-d communication network with local clustering and geographic separations. The network consists of nodes and randomly distributed hubs where the top five hubs ranked according to their coefficient of betweenness centrality (CBC) are connected by random assortative and gradient mechanisms. For multiple message traffic, messages can trap at the high CBC hubs, and congestion can build up on the network with long queues at the congested hubs. The queue lengths are seen to synchronize in the congested phase. Both complete and phase synchronization are seen, between pairs of hubs. In the decongested phase, the pairs start clearing and synchronization is lost. A cascading master-slave relation is seen between the hubs, with the slower hubs (which are slow to decongest) driving the faster ones. These are usually the hubs of high CBC. Similar results are seen for traffic of constant density. Total synchronization between the hubs of high CBC is also seen in the congested regime. Similar behavior is seen for traffic on a network constructed using the Waxman random topology generator. We also demonstrate the existence of phase synchronization in real internet traffic data.

  1. An application of program unification to priority queue vectorization

    SciTech Connect

    Chuang, Ling-Yu (NTHU, HsinChu (Taiwan, Province of China)); Rego, V.; Mathur, A. (Oak Ridge National Laboratory, TN (United States))

    1992-06-01

    In this experimental study, we apply the technique of program unification to priority queues. We examine the performance of a variety of unified priority queue implementations on a Cray Y-MP. The scope of the study is restricted to determining if different implementations of priority queues exhibit markedly different performance characteristics under program unification. We found this to be true. In a larger view, this result has interesting consequences in the application of program unification to discrete event simulations on vector or SIMD machines. We find the heap to be a promising data structure in the program unification paradigm.

  2. 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.

  3. 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.

  4. Large-scale optical backboard bus

    Microsoft Academic Search

    S. Yamaguchi; Tsuyoshi Hayashi; Yukiharu Ohno; Tetsuo Mikazuki

    1997-01-01

    This paper describes an innovative high-speed optical backboard bus composed of an optical star coupler, optical-transmitter (E\\/O) modules, optical-receiver (O\\/E) modules, and optical multimode glass fibers. A highly efficient optical coupling structure with an aspherical lens and a laser diode was designed to achieve coupling efficiency of up to 90%, enabling the distribution of optical signals at up to 1

  5. 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.

  6. QUARK Users' Guide QUeueing And Runtime for Kernels

    E-print Network

    Tennessee, University of

    QUARK Users' Guide QUeueing And Runtime for Kernels Version: April 2011 Electrical Engineering Dongarra #12;Contents 1 Introduction 3 1.1 Overview of QUARK Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Basic Usage of the QUARK

  7. 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.

  8. Conditional dynamics of non-Markovian, infinite-server queues

    E-print Network

    Weber, Theophane

    2005-01-01

    We study the transient dynamics of a partially observed, infinite server queue fed with a Poisson arrival process whose controlled rate is changed at discrete points in time. More specifically, we define a state that ...

  9. 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 ...

  10. 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

  11. Optimal routing in general finite multi-server queueing networks.

    PubMed

    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

  12. A Report on Stochastic Fairness Queueing (SFQ) Experiments

    NASA Technical Reports Server (NTRS)

    Denny, Barbara A.

    1993-01-01

    SRI International (SRI) has developed an improved queueing algorithm, known as Stochastic Fairness Queueing (SFQ), for best-effort traffic (i.e., traffic that does not require any guaranteed service). SFQ is a probablistic variant of strict fair queueing where instead of a single queue being allocated per flow, a fixed number of queues are used and a hash function maps the IP source and destination to a particular queue. A seed to the hash function is also perturbed occasionally to help distribute the flows amongst different queues when more than one flow maps to the same queue during the lifetime of the flow. SFQ provides 'fair' access by trying to ensure that each flow from source to destination host obtains equal access to the available bandwidth. This report covers a series of experiments performed on DARTnet evaluating the behavior and performance of SFQ against a FIFO queueing discipline. These experiments were designed to show SFQ's advantages and performance, and include tests demonstrating: Fair utilization of available resources; Starvation prevention; Graceful degradation under overload conditions; and Resource usage. In general, the experiments do show that SFQ is better than FIFO queueing at allocating bandwidth equally among a set of flows. SFQ also prevents a stream from dominating the available bandwidth, which seems to be a tendency with FIFO queueing (i.e., if a flow demands more than its share of the available bandwidth, with FIFO queueing that stream receives a disproportionate amount when compared to flows demanding less than their share). Furthermore, SFQ seems to reward 'nice' users of the network by providing a lower variance in delay and more throughput when their resource demand is less than their available share. Both SFQ and FIFO queueing seem to degrade fairly well as the network becomes saturated and to recover well as the network becomes less congested. Not unexpectedly, FIFO queueing is a little more efficient than SFQ-the delays are less and the throughput slightly higher because SFQ requires more processing. However, the performance difference between the two queueing disciplines is relatively small. However, the experiments do point out some interesting behavior. FIFO queueing can behave better than SFQ with seed perturbation. We recommend further evaluation of the hash function and the seed perturbation technique. There are probably weaknesses in their current selection that cause this unexpected behavior. SFQ also seems to possess good scaling properties. To verify this, more experiments with a larger number of streams from more hosts need to be executed and examined, including the staggered introduction of streams. Staggering the streams may prove important, because graphs in the degradation experiment revealed some unexpected increases and decreases in throughput, which should be examined. This may again be due to the interaction of the hash function with the seed perturbation but it may also be related to some other unknown problem.

  13. Entropy maximisation and open queueing networks with priorities and blocking

    Microsoft Academic Search

    Demetres D. Kouvatsos; Irfan-ullah Awan

    2003-01-01

    A review is carried out on the characterisation and algorithmic implementation of an extended product-form approximation, based on the principle of maximum entropy (ME), for a wide class of arbitrary finite capacity open queueing network models (QNMs) with service and space priorities. A single server finite capacity GE\\/GE\\/1\\/N queue with R (R>1) distinct priority classes, compound Poisson arrival processes (CPPs)

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

    E-print Network

    Vasquez Pariente, Marta Irene

    1996-01-01

    CYCLE TIME V~ILITY FOR A NETWORK. UNDER TWO QUEUEING DISCIPLINES A Thesis by MARTA IRENE VASQUEZ PARIENTE Submitted to the Office of Graduate Studies of Texas A@M University in partial fulfilhnent of the requirements for the degree of MASTER... OF SCIENCE May 1996 Major Subject: Industrial Engineering CYCLE TIME VARIABILITY FOR A NETWORK UNDER TWO QUEUEING DISCIPLINES A Thesis by MARTA IRENE VASQUEZ PARIENTE Submitted to Texas AdtM University in partial fulfillment of the requirements...

  15. Evaluation of concurrent priority queue algorithms. Technical report

    SciTech Connect

    Huang, Q.

    1991-02-01

    The priority queue is a fundamental data structure that is used in a large variety of parallel algorithms, such as multiprocessor scheduling and parallel best-first search of state-space graphs. This thesis addresses the design and experimental evaluation of two novel concurrent priority queues: a parallel Fibonacci heap and a concurrent priority pool, and compares them with the concurrent binary heap. The parallel Fibonacci heap is based on the sequential Fibonacci heap, which is theoretically the most efficient data structure for sequential priority queues. This scheme not only preserves the efficient operation time bounds of its sequential counterpart, but also has very low contention by distributing locks over the entire data structure. The experimental results show its linearly scalable throughput and speedup up to as many processors as tested (currently 18). A concurrent access scheme for a doubly linked list is described as part of the implementation of the parallel Fibonacci heap. The concurrent priority pool is based on the concurrent B-tree and the concurrent pool. The concurrent priority pool has the highest throughput among the priority queues studied. Like the parallel Fibonacci heap, the concurrent priority pool scales linearly up to as many processors as tested. The priority queues are evaluated in terms of throughput and speedup. Some applications of concurrent priority queues such as the vertex cover problem and the single source shortest path problem are tested.

  16. Exclusive Queueing Processes and their Application to Traffic Systems

    E-print Network

    Arita, C

    2014-01-01

    The dynamics of pedestrian crowds has been studied intensively in recent years, both theoretically and empirically. However, in many situations pedestrian crowds are rather static, e.g. due to jamming near bottlenecks or queueing at ticket counters or supermarket checkouts. Classically such queues are often described by the M/M/1 queue that neglects the internal structure (density profile) of the queue by focussing on the system length as the only dynamical variable. This is different in the Exclusive Queueing Process (EQP) in which the queue is considered on a microscopic level. It is equivalent to a Totally Asymmetric Exclusion Process (TASEP) of varying length. The EQP has a surprisingly rich phase diagram with respect to the arrival probability alpha and the service probability beta. The behavior on the phase transition line is much more complex than for the TASEP with a fixed system length. It is nonuniversal and depends strongly on the update procedure used. In this article, we review the main propertie...

  17. An efficient bus architecture for system-on-chip design

    Microsoft Academic Search

    B. Cordan

    1999-01-01

    This paper presents the issues confronted when integrating system-on-chip (SOC) designs and offers solution through a detailed description of the CoreFrameTM system-on-chip bus architecture that has dramatically reduced system design and verification effort while enhancing the reusability and customizability of system-on-chip product developments. The CoreFrame on-chip bus architecture is defined along with examples to illustrate how a design friendly bus

  18. 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.

  19. Reliable Fiber Sensor System with Star-Ring-Bus Architecture

    PubMed Central

    Peng, Peng-Chun; Wang, Jun-Bo; Huang, Kuan-Yan

    2010-01-01

    This work presents a novel star-ring-bus sensor system and demonstrates its effectiveness. The main trunk of the proposed sensor system is a star topology and the sensing branches comprise a series of bus subnets. Any weakness in the reliability of the sensor system is overcome by adding remote nodes and switches to the ring and bus subnets. To construct the proposed star-ring-bus sensor system, a fiber ring laser scheme is used to improve the signal-to-noise ratio of the sensor system. The proposed system increases the reliability and capacity of fiber sensor systems. PMID:22399876

  20. The missile GINA bus - Remote measurement and restoration

    NASA Astrophysics Data System (ADS)

    Boulanger, G.; Lefeuvre, C.

    The transmission to ground of the data of the missile GINA bus permits very useful exploitation of informations. Due to the diversity of data, the bus interface unit works in two ways: 'addressed' mode and 'spy' mode, which are used in the various on-board units. In practice the use of standard IRIG for telemetry, whose rate is independent of the functional chain under control, requires a temporary memory, dating of bus transfers, and a higher average rate of PCM delivered data than the rate of bus transfers.

  1. 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.

  2. Reliable fiber sensor system with star-ring-bus architecture.

    PubMed

    Peng, Peng-Chun; Wang, Jun-Bo; Huang, Kuan-Yan

    2010-01-01

    This work presents a novel star-ring-bus sensor system and demonstrates its effectiveness. The main trunk of the proposed sensor system is a star topology and the sensing branches comprise a series of bus subnets. Any weakness in the reliability of the sensor system is overcome by adding remote nodes and switches to the ring and bus subnets. To construct the proposed star-ring-bus sensor system, a fiber ring laser scheme is used to improve the signal-to-noise ratio of the sensor system. The proposed system increases the reliability and capacity of fiber sensor systems. PMID:22399876

  3. Using Archived AVL/APC Bus Data to Identify Spatial-Temporal Causes of Bus Bunching Wei Feng, Miguel A. Figliozzi

    E-print Network

    Bertini, Robert L.

    15 Using Archived AVL/APC Bus Data to Identify Spatial-Temporal Causes of Bus Bunching Wei Feng environment, better understanding the main causes and consequences of bus bunching can greatly aid transit causes of bus bunching. This research is utilizes half year's data from automatic vehicle location (AVL

  4. 49 CFR 605.18 - Comments by private school bus operators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Comments by private school bus operators. 605.18 Section 605.18 ...TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.18 Comments by...

  5. 49 CFR 605.18 - Comments by private school bus operators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  6. Measurement of light capture in solar cells from silver- and tin-plated patterned bus bars

    E-print Network

    Winiarz, Christine Eve

    2007-01-01

    Bus bars on solar cells shade silicon from light. When the bus bars are patterned, they can reflect light back onto the silicon using total internal reflection. These patterned bus bars are tin plated and produce 1-2.5% ...

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

    E-print Network

    Sun, Feng

    2009-05-15

    . Based on the principle of maximum entropy, Kouvatsos [24] and Walstra [47] presented a product-form solution for open and closed queueing networks with FCFS discipline and multiple job classes. By applying the Brownian system theory to closed queueing...

  8. 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 ...

  9. A Comparison of Five Different Multiprocessor SoC Bus Architectures

    Microsoft Academic Search

    Kyeong Keol Ryu; Eung S. Shin; Vincent John Mooney III

    2001-01-01

    The performance of a system, especially a multiprocessor system, heavily depends upon the efficiency of its bus architecture. In System-on-a-Chip (SoC), the bus architecture can be devised with advantages such as shorter propagation delay (resulting in a faster bus clock), larger bus width, and multiple buses. This paper presents five different SoC bus architectures for a multiprocessor system: Global Bus

  10. An Energy Reference Bus Independent LMP Decomposition Algorithm

    E-print Network

    @ece.uiuc.edu). ,i kw Marginal generator contribution factor m n× x y If 1m× x and 1n× y I. INTRODUCTION to load variation are used as the basis of this decomposition model. The theoretical derivation balance functions ( )qf X Bus reactive power balance functions ,P QD D Bus real/reactive power load

  11. Research on universal design of interior layout of the bus

    Microsoft Academic Search

    Hui Zhu; Zhigang Huang

    2010-01-01

    In the view of comparing the bus situation at home and abroad, based on theories of knowledge ergonomics, body size, physiological anatomy, design psychology, modern design aesthetics and color science, through comparative analysis of design programs, combined with the market evaluation we fix the universal design program of interior layout of the bus in 10 design programs., It is not

  12. Read This Before You Buy Your Next School Bus.

    ERIC Educational Resources Information Center

    Shannon, Paul

    1981-01-01

    To avoid losing money when buying a bus, a school board should know its district's needs, use the district transportation officer's expertise, investigate local dealers' credentials, learn about differences in bus quality, follow detailed specifications, and pay promptly upon purchase. (RW)

  13. Power Electric Aiding Controller for Automated Bus Stopping

    E-print Network

    Paris-Sud XI, Université de

    Power Electric Aiding Controller for Automated Bus Stopping Jorge Godoy, Vicente Milanés, Joshue-CSIC {jorge.godoy, vicente.milanes, joshue.perez, jorge.villagra, carlos.gonzalez}@car.upm-csic.es Abstract bus lanes, electrical and hydrogen buses and rail-guided buses have been tested and implemented

  14. Cut out Bus Structure and fold as shown.

    E-print Network

    Waliser, Duane E.

    Cut out Bus Structure and fold as shown. Glue edges labeled "Tab" as shown. Leave the Side Engine tabs un-glued. Cut out side engines as shown. Glue side engines to bus structure tabs as shown. #12;Cut out Instrument Assembly and fold as shown. Glue edges labeled "Tab" as shown. Glue Instrument Assembly

  15. The industrial organization of competition in local bus services

    E-print Network

    Paris-Sud XI, Université de

    (bus, train, underground, and tramway). Second, while the modal share of bus transport services has raises the calls for promoting urban mass transit (as opposed to private car). This chapter is aimed predictions of the economic literature. The analysis is summarized as follows. Section 1 reviews what

  16. 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.

  17. Laboratory exercises using a graphical user interface to a queueing simulator

    Microsoft Academic Search

    Edward A. Billard; Alice E. Riedmiller

    1997-01-01

    The study of queueing systems presents mathematical barriers to the novice, although the phenomena of queues can be readily observed in everyday life. In addition, English-speaking faculty have language barriers to surmount with Japanese students. This paper describes a graphical user interface to allow quick and easy comprehension of the dynamical behavior of queues. The interface is implemented using Tcl\\/Tk,

  18. Multi-Robot Formations based on the Queue-Formation Scheme with Limited Communications

    E-print Network

    Ge, Shuzhi Sam

    Multi-Robot Formations based on the Queue-Formation Scheme with Limited Communications Cheng, IEEE Abstract-- In this paper, we investigate the operation of the Queue-formation structure (or Q into formation. It provides greater control over the distance between robots on the same queue for better

  19. Effect of Exponential Averaging on the Variability of a RED Queue

    E-print Network

    Baras, John S.

    Effect of Exponential Averaging on the Variability of a RED Queue Archan Misra Teunis Ott John occupancy affects the stability and variabilityof a RED queue. Extensive simulation studies with both persistent and Web TCP sources are used to study the variance of the RED queue as a function of the memory

  20. Measuring Queue Capacities of IEEE 802.11 Wireless Access Points

    E-print Network

    Claypool, Mark

    of wireless access points (APs). This paper presents and deploys the Access Point Queue (APQ) methodology for externally estimating the queue capacity for a wireless AP. APQ determines the AP saturation point, measures residential class APs. The wireless AP queue capacities are shown to be packet-based and to range from 50

  1. AVERAGE CASEANALYSIS OF PRIORITY TREES: A STRUCTURE FOR PRIORITY QUEUE ADMINISTRATION

    E-print Network

    Prodinger, Helmut

    AVERAGE CASE­ANALYSIS OF PRIORITY TREES: A STRUCTURE FOR PRIORITY QUEUE ADMINISTRATION ALOIS of key comparisons when inserting an element between j and j + 1, the number of key comparisons when) are a data structure to implement priority queues. There exist applications of priority queues e. g

  2. AVERAGE CASE-ANALYSIS OF PRIORITY TREES: A STRUCTURE FOR PRIORITY QUEUE ADMINISTRATION

    E-print Network

    Prodinger, Helmut

    AVERAGE CASE-ANALYSIS OF PRIORITY TREES: A STRUCTURE FOR PRIORITY QUEUE trees (or "p-trees" for short) are a data structure to implement prior* *ity queues. There exist and in discrete event simulation models. Each element in a * *priority queue has a fixed associated key value

  3. Reducing Design Complexity of the Load/Store Queue Il Park, Chong Liang Ooi, and T. N. Vijaykumar

    E-print Network

    Vijaykumar, T. N.

    on the load/store queue in terms of capacity and search bandwidth. The load/store queue is a CAM structure despite the faster clock and wider pipeline. To address this problem, a lot of research has been done band- width in the load/store queue. The load/store queue is a CAM structure that supports simultaneous

  4. 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.

  5. Simple queueing model applied to the city of Portland

    SciTech Connect

    Simon, P.M.; Nagel, K. [Los Alamos National Lab., NM (United States)]|[Santa Fe Inst., NM (United States)

    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.

  6. The wheels on the bus go "buy buy buy": school bus advertising laws.

    PubMed

    Pomeranz, Jennifer L

    2012-09-01

    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

  7. 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.

  8. 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.

  9. Classroom Activities in School Bus and Pedestrian Safety Education. Bulletin No. 93138.

    ERIC Educational Resources Information Center

    Wisconsin State Dept. of Transportation, Madison.

    School bus and related pedestrian safety education is prevention-oriented so that students will learn how to avoid bus-related accidents. This manual provides lesson plans emphasizing the school bus stop, loading and unloading zones, emergency evacuation drills, and appropriate behavior on the school bus. The guide also recognizes demographic…

  10. Bus Fleet Type and Age Replacement Optimization: A case study utilizing King County Metro fleet data

    E-print Network

    Bertini, Robert L.

    1 Bus Fleet Type and Age Replacement Optimization: A case study utilizing King County Metro fleet and a hybrid bus. Employing real-world bus fleet data from King County Metro (Washington State, USA) multiple Metro (Washington State, USA) operates about 1,300 vehicles with multiple bus technologies (electric

  11. Dual Diagnosis

    Microsoft Academic Search

    Mark S. Gold

    2005-01-01

    It is estimated that 10 million persons in me United States have at least one mental disorder and at least one substance-related disorder in any given year. Dual disorders are common in psychiatry, but misdiagnosis may be even more common. Drug and alcohol testing should be expanded from routine use in the Olympics and intercollegiate athletics to psychiatric diagnosis of

  12. Dual photography

    Microsoft Academic Search

    Pradeep Sen; Billy Chen; Gaurav Garg; Stephen R. Marschner; Mark Horowitz; Marc Levoy; Hendrik P. A. Lensch

    2005-01-01

    We present a novel photographic technique called dual photography, which exploits Helmholtz reciprocity to interchange the lights and cameras in a scene. With a video projector providing structured illumination, reciprocity permits us to generate pictures from the viewpoint of the projector, even though no camera was present at that location. The technique is completely image-based, requiring no knowledge of scene

  13. 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 and Economics Department of Telecommunications 1521 Budapest, Hungary Email: telek@webspn.hit.bme.hu Mikl´os V´ecsei Budapest University of Technology and Economics Department of Telecommunications 1521 Budapest, Hungary

  14. Control of queues with MAP servers: experimental results

    E-print Network

    Telek, Miklós

    Technical Univ. of Budapest ghorvath@hit.bme.hu András Mészáros Technical Univ. of Budapest meszarosa@hit.bme.hu Miklós Telek Technical Univ. of Budapest telek@hit.bme.hu ABSTRACT The paper considers simple queueing

  15. Recommendations on Queue Management and Congestion Avoidance in the Internet

    Microsoft Academic Search

    Bob Braden

    1997-01-01

    This memo presents two recommendations to the Internet community concerning measuresto improve and preserve Internet performance. It presents a strong recommendationfor testing, standardization, and widespread deployment of active queue managementin routers, to improve the performance of today's Internet. It also urges aconcerted effort of research, measurement, and ultimate deployment of router mechanismsto protect the Internet from flows that are not

  16. Recommendations on Queue Management and Congestion Avoidance in the Internet

    Microsoft Academic Search

    B. Braden; D. Clark; J. Crowcroft; UCL B. Davie; S. Deering; D. Estrin; V. Jacobson; G. Minshall; C. Partridge; BBN L. Peterson; K. Ramakrishnan; S. Shenker; LCS L. Zhang

    1998-01-01

    This memo presents two recommendations to the Internet community concerning measures to improve and preserve Internet performance. It presents a strong recommendation for testing, standardization, and widespread deployment of active queue management in routers, to improve the performance of today's Internet. It also urges a concerted effort of research, measurement, and ultimate deployment of router mechanisms to protect the Internet

  17. Job queues and the union status of workers

    Microsoft Academic Search

    John M. Abowd; Henry S. Farber

    1982-01-01

    This paper develops a model of the determination of the union status of workers that allows for the possibility of queuing for union jobs. The empirical results derived, using a sample from the University of Michigan Panel Study of Income Dynamics, are supportive of the queuing hypothesis. The no-queue model can be rejected using a likelihood-ratio test. This suggests that

  18. Accelerate In-Line Packet Processing Using Fast Queue

    E-print Network

    Chen, Sheng-Wei

    in the Linux operating system. Based on the observation, a new software architecture, named Fast Queue show that the proposed software architecture re- duces 30% of CPU utilization. In addition, the overall. Undesirable network traffic, in- cluding multimedia streams, game traffic, peer-to-peer shares, or network

  19. ETL Queues for Active Data Warehousing Alexandros Karakasidis

    E-print Network

    Pitoura, Evaggelia

    ETL Queues for Active Data Warehousing Alexandros Karakasidis Univ. of Ioannina Ioannina, Hellas alex@cs.uoi.gr Panos Vassiliadis Univ. of Ioannina Ioannina, Hellas pvassil@cs.uoi.gr Evaggelia Pitoura Univ. of Ioannina Ioannina, Hellas pitoura@cs.uoi.gr ABSTRACT Traditionally, the refreshment of data

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

    E-print Network

    Maggs, Bruce M.

    Institute. Department of Computer Science, University of Massachusetts, Amherst, MA 01003 (ramesh@ cs.umass.SIMPLE ALGORITHMS FOR ROUTING ON BUTTERFLY NETWORKS WITH BOUNDED QUEUES BRUCE M. MAGGS AND RAMESH K, either express or implied, of AFMC, ARPA, CMU, UMASS, or the U.S. Government. http://www.siam.org/journals

  1. 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

  2. An Adaptive RIO (A-RIO) Queue Management Algorithm

    Microsoft Academic Search

    Julio Orozco; David Ros

    2003-01-01

    In the context of the DiServ architecture, active queue management (AQM) algorithms are used for the dieren tiated forwarding of packets. However, correctly setting the parameters of an AQM algorithm may prove dicult and error- prone. Besides, many studies have shown that the performance of AQM mechanisms is very sensitive to network conditions. In this paper we present an adaptive

  3. Delay Analysis of Priority Queues with Modulated Traffic

    E-print Network

    Imperial College, London

    a DiffServ node which is modelled as a non-pre-emptive priority queue with modulated arrivals and derive-world applications; in the example considered here, it could model a DiffServ router which provides service and industry. The Differentiated Services (DiffServ) model, proposed as a simple and scalable mechanism

  4. Queueing networks with dependent nodes and concurrent movements

    Microsoft Academic Search

    Richard F. Serfozo

    1993-01-01

    Classical queueing network processes are useful for modeling the movement of discrete units in a network in which the nodes operate independently, the routing of units is independent of the congestion, only one unit moves at a time and its equilibrium distribution is a well-understood product form. Actual networks, however, typically have dependent nodes and concurrent movement of units. Imagine

  5. Maximizing throughput in queueing networks with limited flexibility

    E-print Network

    Karakostas, George

    to indicate the stage of processing. The customers are serviced by a set of flexible servers, i.e., a server a queueing network where customers go through several stages of processing, with the class of a customer used may be capable of serving more than one class of customer and the sets of classes that the servers

  6. Design and implementation of an efficient priority queue

    Microsoft Academic Search

    P. van Emde Boas; R. Kaas; E. Zijlstra

    1976-01-01

    We present a data structure, based upon a hierarchically decomposed tree, which enables us to manipulate on-line a priority queue whose priorities are selected from the interval 1,?,n with a worst case processing time of\\u000a

  7. Performance analysis of cloud with queue-dependent virtual machines

    Microsoft Academic Search

    V. Goswami; S. S. Patra; G. B. Mund

    2012-01-01

    Cloud computing provides a new way for industries to meet the emerging business need for agility. Many public clouds are available for developers to build web applications on cloud. The process of entering into the cloud is generally in the form of a queue, so that each user need to wait until the current user is being served. In the

  8. ON THE WORKLOAD PROCESS IN A FLUID QUEUE WITH

    E-print Network

    to message discarding at the network element and thus the system was effectively open-loop+ The discarding a feedback system consisting of a finite buffer fluid queue and a responsive source+ The source alternates that only those bursts at whose commencement epoch ~the instant at which the source is ready to send

  9. APPROXIMATE DISAGGREGATION--AGGREGATION SOLUTIONS FOR GENERAL QUEUEING NETWORKS

    E-print Network

    Strelen, Christoph

    or even impossible due to computational complexity. In order to obtain perfor­ mance measures like of the Markov chain. Unfortunately, the number of states grows quickly as the complexity of the model increases CHAINS FOR QUEUEING NETWORKS Irreducible aperiodic Markov chains (Z(t); t 2 IN ), discrete

  10. Large deviation results for time-dependent queue length distributions

    Microsoft Academic Search

    Søren Asmussen; Hermann Thorisson

    1988-01-01

    A normal approximation of the form [um0001] is derived for the stable GI\\/G\\/1 queue length process as well as for the level process {Qn} of Markov chains {(In,Qn)} having a matrix-geometric stationary distribution.

  11. Energy Consumption in Coded Queues for Wireless Information Exchange

    E-print Network

    Boucherie, Richard J.

    Energy Consumption in Coded Queues for Wireless Information Exchange Jasper Goseling, Richard J customers. We use this relation to ob- tain bounds on the energy consumption in a wireless information, for example, from the observations in [3] that using network coding can reduce the energy consumption

  12. On high-speed data bus performance analysis

    NASA Astrophysics Data System (ADS)

    Ludvigson, M. T.

    The use of average throughput analysis in determining the relative performance of high-speed data bus networks is examined. The performance of four different linear bus implementations and the SAE ring bus are considered in terms of low to moderate, high, and worst case throughput delays, and theoretical maximum throughput. It is found that average performance analysis is not a reliable predictor for bus performance at high levels of randomly offered traffic. For linear buses, it was found that preamble, token, and station response time had a significant effect on average performance. It is suggested that ring buses operating at the same data rates will experience significantly longer maximum (worse case) delays than linear buses.

  13. Distributed shared memory multiprocessors using multistage bus networks

    E-print Network

    Iyer, Ravishankar

    1996-01-01

    Distributed shared memory (DSM) multiprocessors rely heavily on the interconnection network performance. The Multistage Bus Network (MBN) is analyzed in this thesis for a DSM environment. The MBN avoids some of the shortcomings of the conventional...

  14. 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

  15. State Bus Fleet Study Documents Fuel-Saving Measures.

    ERIC Educational Resources Information Center

    Collings, Amy

    1990-01-01

    A demonstration program conducted in 12 New Jersey school districts identified 18 fuel cost-saving opportunities for school bus operation that could save the state an estimated $1.6 million in fuel costs. (MLF)

  16. CAL ID Card and Bus Pass CAL 1 Card Office

    E-print Network

    California at Irvine, University of

    Campus Map CAL ID Card and Bus Pass CAL 1 Card Office 110 Cesar Chavez Center Checking your Account (SHIP) University Health Services University Sports Facility and Gym EECS­ SPECIFIC RESOURCES Center

  17. Design of route guidance information for elderly bus passengers

    E-print Network

    Cheng, Pei Pei

    1992-01-01

    . Make any changes necessary to develop a more effective way to present route guidance information to elderly bus passengers. Test to see if and how the changes help elderly people in using route guidance information to successfully reach desired...

  18. Spin-bus concept of spin quantum computing

    SciTech Connect

    Mehring, Michael; Mende, Jens [2. Physikalisches Institut, University of Stuttgart (Germany)

    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.

  19. DIMETHYL ETHER (DME)FUELED SHUTTLE BUS DEMONSTRATION PROJECT

    Microsoft Academic Search

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

    2003-01-01

    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

  20. Development of fiber optic data bus for aircraft

    Microsoft Academic Search

    Yutaka Komouchi; Akira Sueoka

    1988-01-01

    An account is given of the design, construction, and both ground and flight testing of a star-coupled fiber-optic data bus consisting of an optic coupler, fibers, a connector, and a transmitter\\/receiver. This system precludes spark\\/fire hazards and crosstalk problems, while offering very small size and weight for a given capability. The communication protocol for the data bus is of 1

  1. Compressed natural gas bus safety: a quantitative risk assessment.

    PubMed

    Chamberlain, Samuel; Modarres, Mohammad

    2005-04-01

    This study assesses the fire safety risks associated with compressed natural gas (CNG) vehicle systems, comprising primarily a typical school bus and supporting fuel infrastructure. The study determines the sensitivity of the results to variations in component failure rates and consequences of fire events. The components and subsystems that contribute most to fire safety risk are determined. Finally, the results are compared to fire risks of the present generation of diesel-fueled school buses. Direct computation of the safety risks associated with diesel-powered vehicles is possible because these are mature technologies for which historical performance data are available. Because of limited experience, fatal accident data for CNG bus fleets are minimal. Therefore, this study uses the probabilistic risk assessment (PRA) approach to model and predict fire safety risk of CNG buses. Generic failure data, engineering judgments, and assumptions are used in this study. This study predicts the mean fire fatality risk for typical CNG buses as approximately 0.23 fatalities per 100-million miles for all people involved, including bus passengers. The study estimates mean values of 0.16 fatalities per 100-million miles for bus passengers only. Based on historical data, diesel school bus mean fire fatality risk is 0.091 and 0.0007 per 100-million miles for all people and bus passengers, respectively. One can therefore conclude that CNG buses are more prone to fire fatality risk by 2.5 times that of diesel buses, with the bus passengers being more at risk by over two orders of magnitude. The study estimates a mean fire risk frequency of 2.2 x 10(-5) fatalities/bus per year. The 5% and 95% uncertainty bounds are 9.1 x 10(-6) and 4.0 x 10(-5), respectively. The risk result was found to be affected most by failure rates of pressure relief valves, CNG cylinders, and fuel piping. PMID:15876211

  2. Interface circuits for the ARINC 429 data bus

    NASA Astrophysics Data System (ADS)

    Kubat, Milan

    Some of the digital data on the L 610 aircraft will be transmitted by a data bus complying with the ARINC 429 standard. Appropriate interface circuits had to be developed in this connection. This paper examines the time characteristics and electrical specifications of this serial data bus and describes the format of transmitted information according to the appropriate communication protocol. Results concerning the feasibility of implementing the interface circuits are discussed.

  3. Digital bus technology in new coal-fired plants

    SciTech Connect

    Blaney, J.; Murray, J. [Emerson Process Management (United States)

    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.

  4. Competing for jobs: labor queues and gender sorting in the hiring process.

    PubMed

    Fernandez, Roberto M; Mors, Marie Louise

    2008-12-01

    While much research has documented the pattern and extent of sex segregation of workers once they are employed, few studies have addressed the pre-hire mechanisms that are posited to produce sex segregation in employment. While the notion of a labor queue-the rank order of the set of people that employers choose among-plays a prominent role in pre-hire accounts of job sex sorting mechanisms, few studies have examined the ways in which job candidates are sorted into labor queues. In this paper, we explore the mechanisms by which labor queues contribute to the gendering of jobs by studying the hiring process for all jobs at a call center. Being placed in a queue has a clear gendering effect on the hiring process: the sex distribution of applicants who are matched to queues and those who are rejected at this phase diverge, and among those assigned to queues, women are prevalent in queues for low pay, low status jobs. The screening process also contributes to the gendering of the population of hires at this firm. Females are more prevalent among hires than they are among candidates at initial queue assignment. Among high status jobs, however, males are more prevalent than females. Moreover, there are important wage implications associated with matching to queues. While there are large between-queue sex differences in the paid wages associated with allocation to queues, once allocated to queues the wage differences between male and female candidates are nil. Consequently, the roots of gender wage inequality in this setting lie in the initial sorting of candidates to labor queues. PMID:19227692

  5. Running the model in production mode: using the queue. High performance computing (HPC) systems use a queue system to make

    E-print Network

    Gerber, Edwin

    Running the model in production mode: using the queue. High performance computing (HPC) systems use. I've worked on three HPC systems to date, and each is quite similar in this regard, although. But processors are connected together in clusters, or nodes, that are more tightly bound together. On NYU's HPC

  6. 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.

  7. QCD dual

    SciTech Connect

    Sannino, Francesco [CP3-Origins, Campusvej 55, DK-5230 Odense M (Denmark)

    2009-09-15

    We uncover a novel solution of the 't Hooft anomaly matching conditions for QCD. Interestingly in the perturbative regime the new gauge theory, if interpreted as a possible QCD dual, predicts the critical number of flavors above which QCD in the nonperturbative regime, develops an infrared stable fixed point. Remarkably this value is identical to the maximum bound predicted in the nonpertubative regime via the all-orders conjectured beta function for nonsupersymmetric gauge theories.

  8. M. Telek, Madrid Conference on Queueing Theory, July 2006. Matrix exponential distributions with minimal coefficient of variation -p. 1/20 Matrix exponential distributions with minimal

    E-print Network

    Telek, Miklós

    M. Telek, Madrid Conference on Queueing Theory, July 2006. Matrix exponential distributions distributions with complex eigenvalues Numerical results Conclusions M. Telek, Madrid Conference on Queueing results Conclusions M. Telek, Madrid Conference on Queueing Theory, July 2006. Matrix exponential

  9. Classroom Note: Calculation of Steady-State Probabilities of M\\/M Queues: Further Approaches (Running title: Calculation of Steady-State Queues)

    Microsoft Academic Search

    David K Smith

    2002-01-01

    Abstract This paper draws attention to the risk of rounding error in the numerical evaluation of steady-state probabilities for the M\\/M family of queues. A method for avoiding the risk is presented which is easy to program for calculation in practice. Key words: Accuracy, computing, queue models.

  10. Application of Fuzzy System on a Server-Dependent Queue Modeled with Empirical Bayesian Estimation

    Microsoft Academic Search

    Pei-chun Lin; Jenhung Wang

    2007-01-01

    This study presents a fuzzy system by collecting membership function and rules based on a decision model that uses empirical\\u000a Bayesian estimation to construct a server-dependent M \\/M \\/2 \\/L queue. A Markovian queue of finite capacity in which the number of servers depends upon queue length is considered. First,\\u000a data on the interarrival times and service times are collected

  11. The M\\/M\\/1 Fork-Join Queue with Variable Sub-Tasks

    Microsoft Academic Search

    Elizabeth Varki; Arif Merchant; Hui Chen

    The fork-join queue models parallel resources where arriving jobs divide into various number of sub-tasks that are assigned to unique devices within the parallel resource. Each device in the parallel resource is modeled by queueing servers. A job completes execution and departs the parallel resource after all its sub-tasks complete execution. This paper analyzes -server fork-join queues where arriving jobs

  12. Delay analysis for multidimensional queueing processes in CSMA\\/CD local area networks

    Microsoft Academic Search

    June S. Park; Keebom Kang

    1993-01-01

    A CSMA\\/CD local area network consists of a single server (the channel) and multiple interacting queues of message packets. The message queueing process in a buffered,p-persistent CSMA\\/CD system is modeled as a multidimensional semi-Markov chain. An effective approximation method to compute the mean packet delay in equilibrium is developed, based on an exact joint probability generating function of the queue

  13. Two tandem queues with general renewal input. 2: Asymptotic expansions for the diffusion model

    SciTech Connect

    Knessl, C.; Tier, C.

    1999-10-01

    In Part 1 the authors formulated and solved a diffusion model for two tandem queues with exponential servers and general renewal arrivals. They thus obtained the easy traffic diffusion approximation to the steady state joint queue length distribution for this network. Here they study asymptotic and numerical properties of the diffusion approximation. In particular, analytical expressions are obtained for the tail probabilities. Both the joint distribution of the two queues and the marginal distribution of the second queue are considered. They also give numerical illustrations of how this marginal is affected by changes in the arrival and service processes.

  14. Two tandem queues with general renewal input -- 1: Diffusion approximation and integral representations

    SciTech Connect

    Knessl, C.; Tier, C.

    1999-10-01

    The authors consider two tandem queues with exponential servers. Arrivals to the first queue are governed by a general renewal process. If the arrivals were also exponentially distributed, this would be a simple example of a Jackson network. However, the structure of the model is much more complicated for general arrivals. They analyze the joint steady-state queue length distribution for this network, in the heavy traffic limit, where the arrival rate is only slightly less than the service rates. The formulate and solve the boundary value problem for the diffusion approximation to this model. They obtain simple integral representations for the (asymptotic) steady-state queue length distribution.

  15. Bus dynamics for mobility-aid securement design.

    PubMed

    Zaworski, Joseph R; Hunter-Zaworski, K M; Baldwin, Matthew

    2007-01-01

    Mobility-aid securement on large urban transit buses has been designed without an adequate knowledge of either the accelerations that are likely to occur in normal operations or the maximum accelerations that are possible short of an impact accident. These normal operation accelerations are important because they are the source of motion and corresponding sense of insecurity on the part of the passenger when riding in a mobility-aid on a bus. This paper describes the equipment and procedures used to measure the distribution of accelerations to be expected on large buses in normal transit service and the maximum accelerations possible during extreme maneuvering for six different sizes and types of transit buses. Included in the tests were low-floor buses of different lengths, a high-floor bus, a 40-ft (12.2-m) low-floor double-decker bus, and a 60-ft (18.3-m) low-floor articulated bus. During in-service tests, the accelerations were generally a function of the driver. In maneuvering tests, the mechanics of the bus design were the controlling factors. The results show that, in general, normal driving accelerations were typically less than 0.2 g in all directions and very rarely greater than 0.4 g. In the event of an emergency-driving situation, forward and turning accelerations may reach 0.4 g and stopping may result in 0.8 g. PMID:18335709

  16. 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.

  17. Arbitrary open queueing networks with server vacation periods and blocking

    Microsoft Academic Search

    Charalabos A. Skianis; Demetres D. Kouvatsos

    1998-01-01

    A cost-effective decomposition algorithm is proposed for the approximate analysis of arbitrary first-come-first-served (FCFS) open queueing network models (QNMs) with Generalised Exponential (GE) external interarrival time and service time distributions, multiple vacation periods, exhaustive service scheme and repetitive service blocking of random destination (RS-RD). The algorithm is based on a new product-form approximation suggested by the information theoretic principle of

  18. On the Jitter Performance of FIFO and Priority Queues Mixture

    Microsoft Academic Search

    Chiara Taddia; Gianluca Mazzini

    2006-01-01

    We investigate the impact of the insertion of routers implementing a non-preemptive priority queue mechanism (PQ) in a chain of simple first-in-first-out (FIFO) routers on the end-to-end jitter experienced by high and low priority packets. The study has been realized from an analytical point of view: we are able to give the explicit form of the total jitter in relation

  19. Stochastic Fair Blue: A Queue Management Algorithm for Enforcing Fairness

    Microsoft Academic Search

    Wu-chang Feng; Dilip D. Kandlur; Debanjan Saha; Kang G. Shin

    2001-01-01

    This paper describes and evaluates Stochastic Fair Blue(SFB), a novel technique for enforcing fairness among a large number of flows. SFB scalably detects and rate-limits non-responsive flows through the use of a marking probability derived from the BLUE queue management algorithm and a Bloom filter. Using analysis and simulation, SFB is shown to effectively handle non-responsive flows using an extremely

  20. 40 CFR 85.1404 - Maintenance of records for urban bus operators; submittal of information; right of entry.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Maintenance of records for urban bus operators; submittal of information...OF AIR POLLUTION FROM MOBILE SOURCES Urban Bus Rebuild Requirements § 85.1404 Maintenance of records for urban bus operators; submittal of...

  1. 40 CFR 85.1404 - Maintenance of records for urban bus operators; submittal of information; right of entry.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Maintenance of records for urban bus operators; submittal of information...OF AIR POLLUTION FROM MOBILE SOURCES Urban Bus Rebuild Requirements § 85.1404 Maintenance of records for urban bus operators; submittal of...

  2. 40 CFR 85.1404 - Maintenance of records for urban bus operators; submittal of information; right of entry.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Maintenance of records for urban bus operators; submittal of information...OF AIR POLLUTION FROM MOBILE SOURCES Urban Bus Rebuild Requirements § 85.1404 Maintenance of records for urban bus operators; submittal of...

  3. 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

    ...2011-07-01 false Maintenance of records for urban bus operators; submittal of information...OF AIR POLLUTION FROM MOBILE SOURCES Urban Bus Rebuild Requirements § 85.1404 Maintenance of records for urban bus operators; submittal of...

  4. 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

    ...2010-07-01 false Maintenance of records for urban bus operators; submittal of information...OF AIR POLLUTION FROM MOBILE SOURCES Urban Bus Rebuild Requirements § 85.1404 Maintenance of records for urban bus operators; submittal of...

  5. 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.

  6. Public transit 1993: Bus, paratransit, and ridesharing. Transportation research record

    SciTech Connect

    Kassabian, N.C.; Tobias, A.G.; Crayton, L.; Solomon, N.; Brown, S.E.G.

    1993-01-01

    Contents: evaluation of the operating cost consequences of signal preemption as an IVHS strategy; efficient transit priority at intersections; welfare comparison of fixed- and flexible-route bus systems; bus stop accessibility: a guide for virginia transit systems and public entities for complying with the americans with disabilities act of 1990; implications of technological developments for demand responsive transit; impact of nonresponse bias on forecasts of average passenger occupancy; what has happened to carpooling: trends in North Carolina, 1980 to 1990; ridesharing and the consumer: a tale of two marketing strategies; transportation demand management at small employer sites; and state of the commute in Southern California, 1992.

  7. 49 CFR 571.131 - Standard No. 131; School bus pedestrian safety devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Standard No. 131; School bus pedestrian safety devices. 571.131 Section...Standard No. 131; School bus pedestrian safety devices. S1. Scope. ...school buses to improve the safety of pedestrians in the vicinity of...

  8. 49 CFR 571.131 - Standard No. 131; School bus pedestrian safety devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Standard No. 131; School bus pedestrian safety devices. 571.131 Section...Standard No. 131; School bus pedestrian safety devices. S1. Scope. ...school buses to improve the safety of pedestrians in the vicinity of...

  9. 49 CFR 571.131 - Standard No. 131; School bus pedestrian safety devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Standard No. 131; School bus pedestrian safety devices. 571.131 Section...Standard No. 131; School bus pedestrian safety devices. S1. Scope. ...school buses to improve the safety of pedestrians in the vicinity of...

  10. 49 CFR 571.131 - Standard No. 131; School bus pedestrian safety devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Standard No. 131; School bus pedestrian safety devices. 571.131 Section...Standard No. 131; School bus pedestrian safety devices. S1. Scope. ...school buses to improve the safety of pedestrians in the vicinity of...

  11. 49 CFR 571.131 - Standard No. 131; School bus pedestrian safety devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Standard No. 131; School bus pedestrian safety devices. 571.131 Section...Standard No. 131; School bus pedestrian safety devices. S1. Scope. ...school buses to improve the safety of pedestrians in the vicinity of...

  12. Dynamic behavior in two-route bus traffic system with real-time information

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2014-11-01

    We study the dynamics of two-route bus traffic system with two buses using a bus choice scenario. The two-route bus traffic system with real-time information is not consistent with the two-route vehicular traffic system but is similar to the vehicular system. The two-route bus traffic system is mimicked by the physically dynamic model. The dynamics of two-route bus traffic system is described by a couple of nonlinear maps. A bus runs a neck- and neck race with another bus. The motion of two buses displays an irregular behavior in a complex manner. We clarify the effect of real-time information on the bus traffic.

  13. The prediction of bus arrival time using Automatic Vehicle Location Systems data 

    E-print Network

    Jeong, Ran Hee

    2005-02-17

    is required. In addition to the prediction interval of bus arrival time, the probability that a given bus is on time was calculated. The probability density function of schedule adherence seemed to be the gamma distribution or the normal distribution...

  14. Using a Single Switch with O(M) Inputs/Outputs for the Construction of an Optical Priority Queue

    E-print Network

    Chang, Cheng-Shang

    the construction of an optical priority queue with a single (M + 1) × (M + 1) switch and M fiber delay lines. The M optical buffers is to direct optical packets through a set of optical Switches and fiber Delay Lines (SDL], and priority queues in [8][9]. In this paper, we focus on the constructions of optical priority queues

  15. A 40-ns 64Mb DRAM with 64-b parallel data bus architecture

    Microsoft Academic Search

    Masao Taguchi; Hiroyoshi Tomita; Toshiya Uchida; Yasuhiro Ohnishi; Kimiaki Sato; Taiji Ema; Masaaki Higashitani; Takashi Yabu

    1991-01-01

    The authors describe circuit techniques for wide input\\/output (I\\/O) data path and high-speed 64-Mb dynamic RAMs (DRAMs). A hierarchical data bus structure using double-level metallization has been developed to form 64-b parallel data bus lines without increasing the chip size. A current-sensing data bus amplifier, developed to sense the 64-b data bus signal in parallel, has made the wide I\\/O

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

    E-print Network

    North Carolina at Chapel Hill, University of

    in a router's queue. This algorithm is called Class-Based Thresholds (CBT). We define a set of traffic classes the average queue occupancy by that class. In CBT, when a packet arrives at the router it is classified determines the ratio between the bandwidth available to each class on the outbound link. CBT and other router

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

    E-print Network

    Jeffay, Kevin

    in a router's queue. This algorithm is called Class­Based Thresholds (CBT). We define a set of traffic classes the average queue occupancy by that class. In CBT, when a packet arrives at the router it is classified determines the ratio between the bandwidth available to each class on the outbound link. CBT and other router

  18. General Solution of Queueing Model with Batch Renewal Arrival by Two Approaches

    Microsoft Academic Search

    Wei Li; Rod J. Fretwell; Demetres D. Kouvatsos

    2010-01-01

    Queueing models with finite capacity and batch arrival or batch service processes are widely recognised as powerful tools for representing transportation networks, flexible manufacturing systems and predicting their performance. Although a considerable progress has been made in the field of analysis of a queue with single server and batch service in the literature, more work is needed to study more

  19. Queueing Analysis of Polling Based Wireless MAC Protocols with Sleep-Wake Cycles

    E-print Network

    Sikdar, Biplab

    1 Queueing Analysis of Polling Based Wireless MAC Protocols with Sleep-Wake Cycles Haiming Yang the per- formance of polling based MAC protocols with sleep-wake cycles for WSNs. A queueing model in ongoing transmissions. Decentralized contention based MAC protocols that use different variants of sleep-wake

  20. Empirical Evaluation of a Queueing Network Model for Semiconductor Wafer Fabrication

    Microsoft Academic Search

    HONG CHEN; J. MICHAEL HARRISON; AVI MANDELBAUM; ANN VAN ACKERE; LAWRENCE M. WEIN

    1988-01-01

    This paper concerns performance modeling of semiconductor manufacturing operations. More specifically, it focuses on queueing network models for an analysis of wafer fabrication facilities. The congestion problems that plague wafer fabrication facilities are described in general terms, and several years' operating data from one particular facility are summarized. A simple queueing network model of that facility is constructed, and the

  1. 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

  2. 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

  3. Selecting Ghosts and Queues from a Car Trackers Output using a Spatio-Temporal Query Language

    E-print Network

    Nebel, Bernhard

    Selecting Ghosts and Queues from a Car Trackers Output using a Spatio-Temporal Query Language of a tracker working on a car traffic scene. The results of two example sets of queries are shown in two videos shows how to find queues of cars in the road traffic scene without prior knowledge of lanes. 1

  4. Transient Loss Performance of a Class of Finite Buffer Queueing Systems Guang-Liang LI *

    E-print Network

    Cui, Jun-Hong

    Transient Loss Performance of a Class of Finite Buffer Queueing Systems Guang-Liang LI * Jun time evolves towards injinity. Tfkerefore, it is important to address performance issues in transient slate. Previous work in transient unalysis of queueing systems usually focuses on Markov models

  5. An Approximate Solution for Ph/Ph/1 and Ph/Ph/1/N Queues

    E-print Network

    Begin, Thomas

    An Approximate Solution for Ph/Ph/1 and Ph/Ph/1/N Queues Alexandre Brandwajn Baskin School approximation to assess the steady-state probabilities of the number of customers in Ph/Ph/1 and Ph/Ph/1/N for the Ph/Ph/1/N queue. The phase-type distributions considered are assumed to be acyclic. Our method

  6. DiffServ Node with Join Minimum Cost Queue Policy: Analysis with Multiclass Traffic

    E-print Network

    Manjunath, D.

    1 DiffServ Node with Join Minimum Cost Queue Policy: Analysis with Multiclass Traffic D. Manjunath--- The DiffServ model is an attractive candidate for providing relative QoS in the Internet. This is also model a DiffServ node as a ``Join Minimum Cost Queue'' in which an ar­ riving customer (packet

  7. Queueing delay - error probability tradeoff for point-to-point channels with fixed length block codes

    Microsoft Academic Search

    Vineeth Bala Sukumaran; Utpal Mukherji

    2011-01-01

    We study the tradeoff between the average error probability and the average queueing delay of messages which randomly arrive to the transmitter of a point-to-point discrete memoryless channel that uses variable rate fixed codeword length random coding. Bounds to the exponential decay rate of the average error probability with average queueing delay in the regime of large average delay are

  8. Optimal and Load Balanced Mapping of Parallel Priority Queues in Hypercubes

    Microsoft Academic Search

    Sajal K. Das; Maria Cristina Pinotti; Falguni Sarkar

    1996-01-01

    We efficiently map a priority queue on the hypercube architecture in a load balanced manner, with no additional communication overhead, and present optimal parallel algorithms for performing insert and deletemin operations. Two implementations for such operations are proposed on the single port hypercube model. In a b-bandwidth, n-item priority queue in which every node contains b items in sorted order,

  9. The solution of separable queueing network models using mean value analysis

    Microsoft Academic Search

    John Zahorjan; Eugene Wong

    1981-01-01

    Because it is more intuitively understandable than the previously existing convolution algorithms, Mean Value Analysis (MVA) has gained great popularity as an exact solution technique for separable queueing networks. However, the derivations of MVA presented to date apply only to closed queueing network models. Additionally, the problem of the storage requirement of MVA has not been dealt with satisfactorily. In

  10. A Model for a Binary Burst-Noise Channel Based on a Finite Queue

    E-print Network

    Alajaji, Fady

    @shannon.mast.queensu.ca and takahara@glen.mast.queensu.ca. pacities and burst frequencies. When q 1 ! 1, the non- uniform caseA Model for a Binary Burst-Noise Channel Based on a Finite Queue Libo Zhong, Fady Alajaji and Glen stationary distribution, capacity and burst frequency of the uniform queue-based chan- nel are presented

  11. Adaptive RED: An Algorithm for Increasing the Robustness of RED's Active Queue Management

    E-print Network

    Floyd, Sally

    Adaptive RED: An Algorithm for Increasing the Robustness of RED's Active Queue Management Sally, under submission Abstract The RED active queue management algorithm allows net- work operators is quite sensitive to the level of congestion and to the RED parameter settings, and is therefore not pre

  12. Adaptive RED: An Algorithm for Increasing the Robustness of RED's Active Queue Management

    E-print Network

    Floyd, Sally

    Adaptive RED: An Algorithm for Increasing the Robustness of RED's Active Queue Management Sally, under submission Abstract The RED active queue management algorithm allows net­ work operators is quite sensitive to the level of congestion and to the RED parameter settings, and is therefore not pre

  13. Adaptive RED: An Algorithm for Increasing the Robustness of RED's Active Queue Management

    Microsoft Academic Search

    Sally Floyd; Ramakrishna Gummadi; Scott Shenker

    2001-01-01

    The RED active queue management algorithm allows net- work operators to simultaneously achieve high throughput and low average delay. However, the resulting average queue length is quite sensitive to the level of congestion and to the RED parameter settings, and is therefore not pre- dictable in advance. Delay being a major component of the quality of service delivered to their

  14. On the value function of the M/Cr/1 queue Sandjai Bhulai

    E-print Network

    Bhulai, Sandjai

    distribution, M/Cr/1 queue, one-step policy improvement, op- timal routing, Poisson equations, value functions.g., Schassberger [17]). This property makes it very useful to approximate general non-negative distributions. Note a single server queueing system to which customers arrive according to a Poisson process. The service times

  15. 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.

  16. Prime Mover and Energy Storage Considerations for a Hydrogen-Powered Series Hybrid Shuttle Bus

    Microsoft Academic Search

    M. M. Flynn; C. S. Hearn; M. C. Lewis; R. C. Thompson; R. G. Longoria

    2007-01-01

    This paper describes simulation results obtained through modeling the operation of a 6.7 m long hydrogen-powered shuttle bus. The actual shuttle bus and its hydrogen refueling station constitute the first of its kind in the state of Texas. The simulations are used to initially verify the stated performance of the shuttle bus and to validate the modeling approach. The vehicle

  17. Design of Electrical Air-Condition Control System for Fuel Cell Vehicle Based on CAN Bus

    Microsoft Academic Search

    Hui Chen; Lin Zhan

    2010-01-01

    This paper introduces the principle of controller area network (CAN) bus and the structure of fuel cell vehicle control system based on CAN bus. It focuses on electrical air -condition control system for fuel cell vehicle based on CAN bus, which consists of an air condition control node and an air condition compressor drive. The design of electrical air condition

  18. Research on designing method of CAN bus and Modbus protocol conversion interface

    Microsoft Academic Search

    Lou Guohuan; Zhang Hao; Zhao Wei

    2009-01-01

    Fieldbus has become one of the most active fields in industrial data bus area. However, fieldbus standards are not uniform at present, which brings many difficulties to different industrial control equipments from different manufacturers to connect their devices to others. CAN bus and Modbus bus are two kinds of more popular buses in industrial control systems. This paper analyses these

  19. Design and Realization of Fire Alarm System Based on CAN Bus

    Microsoft Academic Search

    Chen Yueping; Gan Fangcheng; Zhang Yongxian

    2007-01-01

    CAN bus is one kind of serial communication bus which support distributed control and real time control effectively. In this paper, an intelligent fire alarm system based on CAN fieldbus technology and multi-single-chip-computer communication system is introduced. CAN (controller area network ) is a fast serial bus that is designed to provide an efficient, reliable and economical link between fire

  20. Power-optimal Encoding for DRAM Address Bus Wei-Chung Cheng and Massoud Pedram

    E-print Network

    Pedram, Massoud

    Power-optimal Encoding for DRAM Address Bus Wei-Chung Cheng and Massoud Pedram University Pyramid code, an optimal code for transmitting sequential addresses over a DRAM bus. Constructed that it minimizes the switching activity on the time-multiplexed address bus from CPU to DRAM. Experimental results

  1. High level communication interface design for integrated MEMS and microinstrument bus

    Microsoft Academic Search

    M. Rodriguez; E. Magdaleno; C. Ferrer; B. Lorente; A. Ayala

    2005-01-01

    A microelectromechanical system (MEMS) merges integrated sensors, microactuators, and low-power electronics. These systems normally have a local sensor communication bus managed by a master node. The purpose of this work is to implement a communication interface that permit connect the integrated MEMS local bus (through the master node) with on a high level microinstrument communication bus. The basic philosophy of

  2. 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…

  3. Bus Communication and Control Protocol Using the Electric Passenger Car Control System

    Microsoft Academic Search

    Jinrui Nan; Li Zai; Zhifu Wang; Jun Wang

    2006-01-01

    CAN bus protocol of auto local area network and SAE J1939 code rules are researched, which application is introduced in this paper. Based on the CAN bus communication protocol, J1939's coding system is formed with CAN Bus 29 bit IDENTIFIER. Refer to J1939, this paper established CAN communication codes and malfunction diagnosis codes used on electric passenger car and puts

  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. Characterizing the range of children's air pollutant exposure during school bus commutes

    Microsoft Academic Search

    Lisa D Sabin; Eduardo Behrentz; Arthur M Winer; Seong Jeong; Dennis R Fitz; David V Pankratz; Steven D Colome; Scott A Fruin

    2005-01-01

    Real-time and integrated measurements of gaseous and particulate pollutants were conducted inside five conventional diesel school buses, a diesel bus with a particulate trap, and a bus powered by compressed natural gas (CNG) to determine the range of children's exposures during school bus commutes and conditions leading to high exposures. Measurements were made during 24 morning and afternoon commutes on

  6. Characterizing the range of children's air pollutant exposure during school bus commutes

    Microsoft Academic Search

    LISA D. SABIN; EDUARDO BEHRENTZ; ARTHUR M. WINER; SEONG JEONG; DENNIS R. FITZ; DAVID V. PANKRATZ; STEVEN D. COLOMEd; SCOTT A. FRUINe

    2004-01-01

    Real-time and integrated measurements of gaseous and particulate pollutants were conducted inside five conventional diesel school buses, a diesel bus with a particulate trap, and a bus powered by compressed natural gas (CNG) to determine the range of children's exposures during school bus commutes and conditions leading to high exposures. Measurements were made during 24 morning and afternoon commutes on

  7. The gaps in satisfaction with transit services among BRT, Metro and Bus riders

    E-print Network

    Minnesota, University of

    The gaps in satisfaction with transit services among BRT, Metro and Bus riders: Evidence from, Metro and Bus services differently? 2. Which service attributes underpin the passengers' perceptions of BRT, Bus and Metro services? 3. Which service attributes contribute to the differences among

  8. An implementation of the IEEE Medical Information Bus Standard

    Microsoft Academic Search

    Carlos H. Salvador; Nicanor Pulido; Jose A. Quiles; Miguel A. Gonzalez

    1993-01-01

    The IEEE P1073 family of documents defines the Medical Information Bus (MIB), which is a local area network for the bidirectional interconnection of medical devices and computers. This network is intended to aid in the registering of information such as alarms from medical instruments, the storage of data gathered by these devices, and their control from a central computer. A

  9. Integrated Fault Tolerant System for Automotive Bus Networks

    Microsoft Academic Search

    Haklin Kimm; Ho-sang Ham

    2010-01-01

    In automotive bus networks all the electronic components are interconnected to transmit and receive signals. The number of vehicles equipped with electronic components is increasing rapidly by replacing traditional mechanical and hydraulic systems. Nowadays most cars are functioning properly via many Electronic Control Units (ECUs), sensors and actuators, among which more than 2500 electronic signals are exchanged. There are several

  10. 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…

  11. Common Spacecraft Bus for Earth Science Decadal Survey Missions

    Microsoft Academic Search

    T. Cook; K. Klaus; M. S. Elsperman

    2010-01-01

    Our study assessed the overall technical and programmatic viability of a Common Spacecraft Bus (CSB) approach that could satify the requirements of multiple Earth Science Decadal Mission programs resulting in cost and schedule savings over individual programs. Our approach developed a Common Payload Interface (CPIF) concept based on assessment of TIER I mission requirements to enable flexibility to the payloads

  12. HYBRID LOOP THERMAL BUS TECHNOLOGY FOR VEHICLE THERMAL MANAGEMENT

    Microsoft Academic Search

    Chanwoo Park; Jon Zuo; Paul Rogers; Jeffery Perez

    Army's next generation vehicles require more electric and electronic devices with increasing power density for improved multi-functionality. The increasing waste heat from these devices will present great challenges to the capabilities of conventional air\\/liquid cooling systems in cooling multiple, high heat flux sources dispersed over the entire vehicle. In this paper, a high performance hybrid loop thermal bus technology for

  13. School Bus Safety Advisory Committee: 1999 Annual Report.

    ERIC Educational Resources Information Center

    Lazenberry, Dennis; Anderson, Barbara

    This report summarizes the deliberations and recommendations of Minnesota's School Bus Safety Advisory Committee (SBSAC). The committee, which operates under the auspices of the Minnesota Department of Public Safety, is charged to study issues affecting the safety of students on school buses, arrive at consensus on ways to improve student safety…

  14. Cascaded Amplifying Quantum Optical Taps: A Robust Noiseless Optical Bus

    SciTech Connect

    Bencheikh, K.; Simonneau, C.; Levenson, J.A. [FRANCE TELECOM/CNET/PAB, Laboratoire de Bagneux, B.P. 107, F-92225 Bagneux Cedex (France)] [FRANCE TELECOM/CNET/PAB, Laboratoire de Bagneux, B.P. 107, F-92225 Bagneux Cedex (France)

    1997-01-01

    Two identical amplifying quantum optical taps, based on noiseless optical parametric amplification and twin beam quantum correlation, have been implemented in a series configuration and experimentally investigated. The result is an optical bus which we have shown to be robust with respect to downstream losses. {copyright} {ital 1996} {ital The American Physical Society}

  15. Power bus decoupling on multilayer printed circuit boards

    Microsoft Academic Search

    Todd H. Hubing; James L. Drewniak; Thomas P. Van Doren; David M. Hockanson

    1995-01-01

    Guidelines for the selection and placement of decoupling capacitors that work well for one-sided or two-sided printed circuit boards are not appropriate for multilayer boards with power and ground planes. Boards without internal planes take advantage of the power bus inductance to help decouple components at the higher frequencies. An effective decoupling strategy for multilayer boards must account for the

  16. 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…

  17. Standardized field bus would improve integrated computer system communications

    SciTech Connect

    Reif, D.R.

    1989-02-13

    A standardized communications protocol for the field bus between various components of a control system and main computer would allow better flexibility of the use of field device and communication methods. How the standard could be organized, and current work on standardization, are discussed in this article.

  18. 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.

  19. Electrical impact of high-speed bus crossing plane split

    Microsoft Academic Search

    Juan Chen; Weimin Shi; Adam J. Norman; P. Ilavarasan

    2002-01-01

    The importance of providing a continuous return current path for high-speed signal design is well recognized. A signal bus crossing a plane split has negative impact on SI (signal integrity) and EMI (electromagnetic interference). This paper provides numerical and\\/or measurement analysis to quantify these effects in the PCB environment, such as waveform distortion, increased crosstalk levels, and excessive radiation. In

  20. Flexible Data Collecting over Distributed Sensors on Enterprise Service Bus

    Microsoft Academic Search

    Jing Cao

    2009-01-01

    Collecting real-time data online is one of the most important works to a water environment information management system. However, water quality automatic monitoring apparatus from different manufactories may comply with heterogeneous field-buses such as Modbus, Profibus, OPC and so on. In this paper, a new data acquisition system on enterprise service bus is designed and implemented to deal with those

  1. 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…

  2. Reducing Address Bus Transitions for Low Power Memory Mapping

    Microsoft Academic Search

    Preeti R. Panda; Nikil D. Dutt

    1996-01-01

    We present low power techniques for mapping arrays in behavioral specifications to physical memory, specifically for memory intensive behaviors that exhibit regularity in their memory access patterns. Our approach exploits this regularity in memory accesses by reducing the number of transitions on the memory address bus. We study the impact of different strategies for mapping arrays in behaviors to physical

  3. A method for predicting the expected life of bus capacitors

    Microsoft Academic Search

    Michael L. Gasperi

    1997-01-01

    Predicting the expected life of motor drive bus capacitors is complicated by several factors: the equivalent series resistance of aluminum electrolytic capacitors is frequency and temperature sensitive; the ripple current is a composite waveform; and the capacitor expected life is very sensitive to operating temperature. This paper describes a method that addresses all these factors by developing separate models for

  4. 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…

  5. Assessment of multi-bus fault-tolerant communications

    Microsoft Academic Search

    V. F. Silva; Paulo Bartolomeu; Joaquim Ferreira; José Alberto Fonseca

    2009-01-01

    The flexible time-triggered CAN protocol supports synchronous and asynchronous traffic over a CAN fieldbus. The use of bus and master redundancy is an evolution to the original FTT definition. A protocol supporting multiple buses and masters has been proposed. This paper presents experimental results allowing to assess the timeliness of the communication system. The conclusion is that the system reacts

  6. Transport Facilitation Committee Contributory Bus Service Charges from 1st

    E-print Network

    Shyamasundar, R.K.

    Transport Facilitation Committee Contributory Bus Service Charges from 1st May 2010 For TIFR and temporary staff on fix salary Sr.No. Category Contribution per month 1 Gross salary less than 10,000/- Rs/Manager Rs.330/- 2 Clerical Staff /Peon/Attendant Rs. 180/- The daily wages/casual labours may form

  7. Electric bus battery-swapping system based on robots

    Microsoft Academic Search

    Qi Hui; Wang Xin

    2012-01-01

    Electric Vehicle which could save energy and protect environment, is an important part of strong smart grid and will be the trend of automotive industry in the future. Nowadays, battery-swapping is the main method of EV charging. In this paper, electric bus battery-swapping system based on robots which includes cartesian robot, stacker and battery charging bay, is introduced considering mechanical

  8. 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…

  9. 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

  10. An Arduino compatible CAN Bus architecture for sailing applications

    E-print Network

    Paris-Sud XI, Université de

    An Arduino compatible CAN Bus architecture for sailing applications K´evin Bruget, Beno^it Clement architecture based on Arduino compatible boards, to be used as an alternative communication system for robotic applications. This combines both, the robustness of CAN and the accessibility of Arduino software

  11. Low-power memory mapping through reducing address bus activity

    Microsoft Academic Search

    Preeti Ranjan Panda; Nikil D. Dutt

    1999-01-01

    Arrays in behavioral specifications that are too large to fit into on-chip registers are usually mapped to off-chip memories during behavioral synthesis. We address the problem of system power reduction through transition count minimization on the memory address bus when these arrays are accessed from memory. We exploit regularity and spatial locality in the memory accesses and determine the mapping

  12. 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…

  13. MPEG4 AVC\\/H.264 decoder with scalable bus architecture and dual memory controller

    Microsoft Academic Search

    Hae-yong Kang; Kyung-ah Jeong; Jung-yang Bae; Young-su Lee; Seung-ho Lee

    2004-01-01

    This paper proposes scalable H.264 video decoder architecture that makes the best use of memory bandwidth, which is the most critical problem during designing real-time multimedia CODEC, and optimizes memory access pattern. The proposed decoder architecture is based on an AHB AMBA system, which uses an ARM core as the main controller, and consists of functional blocks such as: VLD,

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

    SciTech Connect

    Martovetsky, Nicolai N [ORNL] [ORNL; Irick, David Kim [ORNL] [ORNL; Kenney, Steven J [ORNL] [ORNL

    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.

  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. 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.

  17. Queues Don’t Matter When You Can JUMP Them!

    E-print Network

    Grosvenor, Matthew P.; Schwarzkopf, Malte; Gog, Ionel; Watson, Robert N. M.; Moore, Andrew W.; Hand, Steven; Crowcroft, Jon

    2015-03-27

    _cycles(network_epoch); 2 long timeout = start_time; 3 long bucket[NUM_QJUMP_LEVELS]; 4 5 int qJumpRateLimiter(struct sk_buff* buffer) { 6 long cycles_now = asm("rdtsc"); /* read cycle ctr */ 7 int level = buffer->priority; 8 if (cycles_now > timeout) { /* new token alloc... : on that generates a constant 10Gb/s of UDP traffic and another that sends fixed-size bursts followed by a 25ms pause. We report interference as the ratio of the burst size to the internal switch buffer size. Beyond a ratio of 200%, permanent queues build up...

  18. SN54LVTH16245A, SN74LVTH16245A 3.3 V ABT 16 BIT BUS TRANSCEIVERS

    E-print Network

    Berns, Hans-Gerd

    Noise D Flow-Through Architecture Optimizes PCB Layout D Ioff and Power-Up 3-State Support Hot Insertion to provide a TTL interface to a 5-V system environment. ORDERING INFORMATION TA PACKAGE ORDERABLE PART NUMBER the A bus to the B bus or from the B bus to the A bus, depending on the logic level at the direction-control

  19. New active queue management mechanism for Web traffic

    NASA Astrophysics Data System (ADS)

    Kasthurirangan, Badri; Wang, Bin; Xu, J.

    2002-07-01

    In this work, we devise and study the performance of a new active queue management mechanism for Web traffic to more intelligently select packets to drop incipient of network congestion. The proposed mechanism specifically targets short-lived or fragile flows (e.g., most HTTP flows) to keep link utilization high while reducing the HTTP response time. The goal of the proposed active queue management scheme is to protect new TCP flows and TCP flows that have packet dropped recently from potential network congestion, thus achieving better response times. Our simulation studies have compared the performance of RED and the proposed AQM for a network with only HTTP traffic at loads less, close to, and more than the network capacity. Simulations show that a subsidy given to a flow that that is in its initial stage provides significantly better performance in terms of HTTP request-reply delays without sacrificing the link utilization. The new scheme is very simple to implement. It contains one additional control parameter to RED, and the tuning of this parameter is simple. Since most HTTP flows are short-lived, only the state information for a subset of active flows needs to be maintained for a very short period of time, and then all the resources used for keeping the state information can be reclaimed.

  20. 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

  1. An asymptotically zero power charge-recycling bus architecture for battery-operated ultrahigh data rate ULSI's

    Microsoft Academic Search

    Hiroyuki Yamauchi; Hironori Akamatsu; Tsutomu Fujita

    1995-01-01

    An asymptotically zero power charge recycling bus (CRB) architecture, featuring virtual stacking of the individual bus-capacitance into a series configuration between supply voltage and ground, has been proposed. This CRB architecture makes it possible to reduce not only each bus-swing but also a total equivalent bus-capacitance of the ultramultibit buses running in parallel. The voltage swing of each bus is

  2. Design and Application of SAE J1939 Communication Database in City-Bus Information Integrated Control System Development

    Microsoft Academic Search

    Jian Hu; Gangyan Li; Xiangpeng Yu; Sheng Liu

    2007-01-01

    With the increase of the number and the complexity of city-bus ECUs (Electronic Control Units), point-to-point link method in traditional city-bus has caused the problems of information exchange, reliability and maintenance. In this paper, we defined the conception of CBIICS (City-Bus Information Integrated Control System) and constructed CBIICS framework with high speed CAN bus and low speed CAN bus so

  3. Learning the Metro Bus System / For Cowell Students This guide summarizes the main bus routes between downtown Santa Cruz and the UCSC campus.

    E-print Network

    Renau, Jose

    with a current validation sticker (or Temporary Bus Pass) ready to show the driver (or pay a $2 fare if no ID to the top front of each campus bus shelter. Even-numbered routes ­ 10-UCSC via High, 16-UCSC via Laurel East

  4. Temporal coupled mode theory in ring-bus-ring configuration

    Microsoft Academic Search

    Y. B. Zhang; S. Darmawan; T. Mei; D. H. Zhang

    2010-01-01

    We develop the temporal coupled mode theory for the ring-bus-ring device by taking account of the energy-conservation. The presence of the center waveguide in the tri-coupler section of the RBR facilitates the interaction between the two side-coupled rings. The correspondence between the coupled mode theory in time and transfer matrix formalism (TMF) is established. A very good agreement is obtained

  5. Scheduling the FlexRay bus using optimization techniques

    Microsoft Academic Search

    Haibo Zeng; Wei Zhengzheng; Marco Di Natale; Arkadeb Ghosal; Paolo Giusto; Alberto L. Sangiovanni-vincentelli

    2009-01-01

    FlexRay is a new communication protocol for automotive systems, providing support for transmission of periodic messages in static segments and priority-based scheduling of event-triggered messages in dynamic segments. The design of a FlexRay schedule is not an easy task because of protocol constraints and demands for extensibility and flexibility. We study the problem of FlexRay bus scheduling from the perspective

  6. 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.

  7. Analysis of a school bus collision: mechanism of injury in the unrestrained child

    PubMed Central

    Lapner, Peter C.; Nguyen, Duong; Letts, Mervyn

    2003-01-01

    Introduction The most common type of school bus crash resulting in injury and death involves the “rollover” mechanism, which may be linked to bus design. To investigate this possibility, we carried out a detailed investigation of a severe school bus crash. Methods The crash involved 12 children, passengers in the school bus. Analysis included the determination of crash dynamics by examination of physical evidence at the crash site and deformation sustained by the structure of the bus and the other vehicle involved. The mechanism of injury was determined by comparing physical evidence collected inside the bus to injuries sustained by the children. Results Two children sustained severe injuries and 1 child was killed. The most common injuries involved the head, neck and shoulder as demonstrated by 3 illustrative reports. Specified changes to school bus design, based on mechanism of injury to the occupants include, in addition to the compartmentalization now in effect, more padding to the sides of the bus, over the window headers and on the panelling between the windows. Conclusions Injuries to the head, neck and spine are the most common types when children are involved in rollover school bus collisions. For additional safety, changes to the current bus design are needed. PMID:12930103

  8. Development and validation of a self-report measure of bus driver behaviour.

    PubMed

    Dorn, Lisa; Stephen, Lucy; af Wåhlberg, Anders; Gandolfi, Julie

    2010-12-01

    There are likely to be individual differences in bus driver behaviour when adhering to strict schedules under time pressure. A reliable and valid assessment of these individual differences would be useful for bus companies keen to mitigate risk of crash involvement. This paper reports on three studies to develop and validate a self-report measure of bus driver behaviour. For study 1, two principal components analyses of a pilot questionnaire revealed six components describing bus driver behaviour and four bus driver coping components. In study 2, test-retest reliability of the components were tested in a sub-sample and found to be adequate. Further, the 10 components were used to predict bus crash involvement at three levels of culpability with consistently significant associations found for two components. For study 3, avoidance coping was consistently associated with celeration variables in a bus simulator, especially for a time-pressured drive. STATEMENT OF RELEVANCE: The instrument can be used by bus companies for driver stress and fatigue management training to identify at-risk bus driver behaviour. Training to reduce the tendency to engage in avoidance coping strategies, improve evaluative coping strategies and hazard monitoring when under stress may improve bus driver safety. PMID:21108079

  9. 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.

  10. 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.

  11. Safety evaluation of a hydrogen fueled transit bus

    SciTech Connect

    Coutts, D.A.; Thomas, J.K.; Hovis, G.L.; Wu, T.T. [Westinghouse Savannah River Co., Aiken, SC (United States)

    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.

  12. 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

  13. 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

  14. Repairable queue with non-exponential service time and variable breakdown rates

    NASA Astrophysics Data System (ADS)

    Khew, Koh Siew; Hin, Pooi Ah; Fei, Tan Yi

    2015-05-01

    Consider a single server queue in which the service station may breakdown according to a Poisson process with rates ? in busy time and ?' in idle time respectively. After a breakdown, the service station will be repaired immediately and the repair time is assumed to have an exponential distribution with rate ?. Suppose the arrival time has an exponential distribution with rate ?, and the probability density function g(t) and the cumulative distribution function G(t) of the service time are such that the rate g(t)/[1 - G(t)] tends to a constant as t tends to infinity. When the queue is in a stationary state, we derive a set of equations for the probabilities of the queue length and the states of the arrival and service processes. Solving the equations, we obtain approximate results for the stationary probabilities which can be used to obtain the stationary queue length distribution of the system.

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

    E-print Network

    Savla, Ketan

    to improve efficiency of human-in-the-loop systems. In this paper, we consider a novel dynamical queue for human operators to increase the overall efficiency of human-in-the-loop systems. In this paper, we

  16. 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 ...

  17. Fluid and Diffusion Approximations of a Two-Station Mixed Queueing Network

    E-print Network

    Nguyen, Viên

    The subject of this paper is a two-station mixed queueing network with two customer types: "Open" customers enter the network at station 1 and depart the system after receiving service. Meanwhile, a fixed number of "closed" ...

  18. An N Server Cutoff Priority Queue Where Customers Request a Random Number of Servers

    E-print Network

    Schaack, Christian

    Consider a multi-priority, nonpreemptive, N-server Poisson arrival queueing system. The number of servers requested by an arrival has a known probability distribution. Service times are negative exponential. In order to ...

  19. Queue observing at the Observatoire du Mont-Mégantic 1.6-m telescope

    NASA Astrophysics Data System (ADS)

    Artigau, Étienne; Lamontagne, Robert; Doyon, René; Malo, Lison

    2010-07-01

    Queue planning of observation and service observing are generally seen as specific to large, world-class, astronomical observatories that draw proposal from a large community. One of the common grievance, justified or not, against queue planning and service observing is the fear of training a generation of astronomers without hands-on observing experience. At the Observatoire du Mont-Mégantic (OMM) 1.6-m telescope, we are developing a student-run service observing program. Queue planning and service observing are used as training tools to expose students to a variety of scientific project and instruments beyond what they would normally use for their own research project. The queue mode at the OMM specifically targets relatively shallow observations that can be completed in less than a few hours and are too short to justify a multi-night classical observing run.

  20. An advanced time-dependent queueing model for airport delay analysis

    E-print Network

    Roth, Emily Jane

    1979-01-01

    Introduction: In the past several years many attempts have been made to model the probabilistic nature of airport runway operations using a queueing-theoretic approach to runway modeling. Early studies were limited by ...

  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. 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.

  3. 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.

  4. 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.

  5. A new simulation approach and its integration with perturbation analysis in tandem queueing systems

    E-print Network

    Jeong, Ki-Young

    1992-01-01

    : Don T, Phillips (Chair of committee) Alberta Garcia-Diaz (Member) Daten B. Cline (Member) Gary J. H (Head ot Departmen August 1992 ABSTRACT A New Simulation Approach and its Integration with Perturbation Analysis in Tandem Queueing Systems.... (August 1992) Ki- Young Jeong, B. E. (Industrial Engr. ), Korea University, Korea Chair of Advisory Committee: Dr. Don T, Phillips This research presents a new simulation approach (NSA) to a single-server tandem queueing system (TQS) and empirically...

  6. A UNIVERSAL ME SOLUTION FOR AN M\\/G\\/1 QUEUE WITH VACATION PERIODS

    Microsoft Academic Search

    Charalabos Skianis; Demetres D. Kouvatsos

    In this paper the information theoretic principle o f Maximum Entropy (ME) is applied, as a method of inference, towards the study of the M\\/G\\/1 queueing model at equilibrium with either single or multiple server vacation periods u nder both exhaustive and non-exhaustive scheduling schemes. An analytic ME approximation for the characterisation of a universal form for the queue length

  7. A maximum entropy priority approximation for a stable G \\/ G \\/1 queue

    Microsoft Academic Search

    Demetres Kouvatsos; Nasreddine Tabet-Aouel

    1989-01-01

    The principle of maximum entropy is used under two different sets of mean value constraints to analyse a stableG\\/G\\/1 queue withR priority classes under preemptive-resume (PR) and non-preemptive head-of-line (HOL) scheduling disciplines. New one-step recursions for the maximum entropy state probabilities are established and closed form approximations for the marginal queue length distribution per priority class are derived. To expedite

  8. 500 Mb\\/s non-precharged data bus for high-speed DRAM

    Microsoft Academic Search

    M. Saito; J. Ogawa; S. Wakayama; H. Tamura; H. Araki; Tsz-Shing Cheung; K. Gotoh; T. Nishi; M. Kawano; T. Aikawa; T. Suzuki; M. Taguchi; T. Imamura

    1998-01-01

    For a DRAM core with bandwidth per memory more than one order of magnitude higher than the current DRAMs without increasing the number of internal busses and the area and power they require, the data rate per DRAM must be increased. This nonprecharged bus combined with a bus amplifier that employs partial response detection (PRD) achieves 500Mb\\/s data-bus rate for

  9. Design of Intelligent Bridge in City-Bus Information Integrated Control System

    Microsoft Academic Search

    Jian Hu; Gangyan Li; Xiude Wu; Jianhua Zhou; Liping Lu

    2006-01-01

    As the main method to improve city-bus service level, CBIICS (city-bus information integrated control system) contains three technical aspects, i.e., city-bus electronic control technology, vehicular network technology and intelligent control technology. In this paper, we firstly defined the conception of CBIICS including definition, object, characteristic, function and target. According to vehicular network protocol and system function, we secondly designed CBIICS

  10. Self-Checking Detection and Diagnosis of Transient, Delay, and Crosstalk Faults Affecting Bus Lines

    Microsoft Academic Search

    Cecilia Metra; Michele Favalli

    2000-01-01

    We present a self-checking detection and diagnosis scheme for transient, delay, and crosstalk faults affecting bus lines of synchronous systems. Faults that are likely to result in the connected logic sampling incorrect bus data are on-line detected. The position of the affected line(s) within the considered bus is identified and properly encoded. The proposed scheme is self-checking with respect to

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

    Microsoft Academic Search

    L. Eudy; K. Chandler

    2012-01-01

    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

  12. SunLine Transit Agency Advanced Technology Fuel Cell Bus Evaluation: Second Results Report and Appendices

    Microsoft Academic Search

    L. Eudy; K. Chandler

    2011-01-01

    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

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

    Microsoft Academic Search

    L. Eudy; K. Chandler

    2011-01-01

    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

  14. Application and implementation of CAN bus technology in industry real-time data communication

    Microsoft Academic Search

    Xiao-feng Wan; Yi-si Xing; Li-xiang Cai

    2009-01-01

    The real-time data communication of real-time operation system is a difficult point. This paper analyzes the functions and characteristics of embedded real-time operation system VxWorks and CAN field bus, and makes use of CAN field bus to realize the data communication between embedded real-time operation system VxWorks and work-site MCU (micro-controller unit). The applications of CAN bus can satisfy the

  15. CAN Modeling and Network Simulation for City-Bus Information Integrated Control System

    Microsoft Academic Search

    Jian Hu; Gangyan Li; Xiangpeng Yu; Jianhua Zhou

    2007-01-01

    With the increase of the number and the complexity of city-bus ECUs (electronic control units), it needs to design city-bus information integrated control system for sharing information and implementing correlative, real-time control between these ECUs. Before city-bus information integrated control system development, it is necessary to simulate and analyse system performance. In this paper, we established CAN model with layered

  16. Implementation of de Bruijn and Kautz bus networks using waveguide holograms

    NASA Astrophysics Data System (ADS)

    Fa, Jinghuai; Chen, Ray T.

    1998-05-01

    In this paper, we discuss multihop optical bus interconnection networks. For massive parallel computing systems, such interconnection can interconnect a large number of processing elements and reduce system latency at the same time. We give the qualitative results of De Bruijn bus network and Kautz bus network as an engineering options based on combinatorial hypergraph theory and a uniform alphabetic constructive method. We also give an implementation method via polymer based waveguide holograms.

  17. The design of electric motor car's body network based on CAN-bus distributed control

    Microsoft Academic Search

    Wang Jianfeng; Wang Dafang; Xiong Jie

    2009-01-01

    CAN-bus is a typical bus control technology, and is now widely applied in many areas.In view of the characteristics of the electric vehicle body, this paper puts forward a plan that applies CAN-bus technology to build electric vehicle body network. In terms of the electric vehicle body system, it needs to resolve several issues: One is to simplify electronic wiring

  18. 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.

  19. A novel fair active queue management algorithm based on traffic delay jitter

    NASA Astrophysics Data System (ADS)

    Wang, Xue-Shun; Yu, Shao-Hua; Dai, Jin-You; Luo, Ting

    2009-11-01

    In order to guarantee the quantity of data traffic delivered in the network, congestion control strategy is adopted. According to the study of many active queue management (AQM) algorithms, this paper proposes a novel active queue management algorithm named JFED. JFED can stabilize queue length at a desirable level by adjusting output traffic rate and adopting a reasonable calculation of packet drop probability based on buffer queue length and traffic jitter; and it support burst packet traffic through the packet delay jitter, so that it can traffic flow medium data. JFED impose effective punishment upon non-responsible flow with a full stateless method. To verify the performance of JFED, it is implemented in NS2 and is compared with RED and CHOKe with respect to different performance metrics. Simulation results show that the proposed JFED algorithm outperforms RED and CHOKe in stabilizing instantaneous queue length and in fairness. It is also shown that JFED enables the link capacity to be fully utilized by stabilizing the queue length at a desirable level, while not incurring excessive packet loss ratio.

  20. Queueing Network-Model Human Processor (QN-MHP): A computational architecture for multitask performance in human-machine systems

    Microsoft Academic Search

    Yili Liu; Robert Feyen; Omer Tsimhoni

    2006-01-01

    Queueing Network-Model Human Processor (QN-MHP) is a computational architecture that in- tegrates two complementary approaches to cognitive modeling: the queueing network approach and the symbolic approach (exemplified by the MHP\\/GOMS family of models, ACT-R, EPIC, and SOAR). Queueing networks are particularly suited for modeling parallel activities and complex structures. Symbolic models have particular strength in generating a person's actions in

  1. 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.

  2. 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.

  3. The universal serial bus endoscope: design and initial clinical experience.

    PubMed

    Hernandez-Zendejas, Gregorio; Dobke, Marek K; Guerrerosantos, Jose

    2004-01-01

    Endoscopic forehead lift is a well-established procedure in aesthetic plastic surgery. Many agree that currently available video-endoscopic equipment is bulky, multipieced and sometimes cumbersome in the operating theater. A novel system, the Universal Serial Bus Endoscope (USBE) was designed to simplify and reduce the number of necessary equipment pieces in the endoscopic setup. The USBE is attached by a single cable to a Universal Serial Bus (USB) port of a laptop computer. A built-in miniaturized cold light source provides illumination. A built-in digital camera chip enables procedure recording. The real-time images and movies obtained with USBE are displayed on the computer's screen and recorded on the laptop's hard disk drive. In this study, 25 patients underwent endoscopic browlift using the USBE system to test its clinical usefulness, all with good results and without complications or need for revision. The USBE was found to be reliable and easier to use than current video-endoscope equipment. The operative time needed to complete the procedure by the authors was reduced approximately 50%. The design and main technical characteristics of the USBE are presented. PMID:15383889

  4. Design and implementation of Directory Service network management system based on event bus pattern

    Microsoft Academic Search

    Jiuqiang Cui; Chunhan Wu

    2010-01-01

    Directory Service is used widely in modern communication networks. In this paper, we proposed and implemented a management system based on event bus pattern to manage directory service network constructed by improving OpenLDAP [1]. The management system presents good architecture while implementing complex management functions. The principles and use of event bus pattern in the system is described in detail

  5. AlAA 92-0980 Design of Multipurpose Spacecraft BUS

    E-print Network

    . The spacecraft bus uses three- axis stabilization consisting of three reaction wheel system. The electric power differences in orbit, yaw axis control, attitude pointing, and thermal control requirements. The AVHRR payloadAlAA 92-0980 Design of Multipurpose Spacecraft BUS 6. N. Agrawal Naval Postgraduate School Monterey

  6. Experience in using a software bus to build reusable scientific software

    Microsoft Academic Search

    W. H. Greiman; D. E. Hall; D. Olson; D. J. Balaban; C. T. Day

    1990-01-01

    We describe our experience in using a software bus architecture (1,2) to build a fault location system from reusable software parts. The system consists of ``plug compatible'' software components connected by a software bus. This architecture makes it possible to assemble the system either as a collection of cooperating distributed processes, or as a single program running on a single

  7. Experience in using a software bus to build reusable scientific software

    Microsoft Academic Search

    W. H. Greiman; D. E. Hall; D. Olson; D. J. Balaban; C. T. Day

    1990-01-01

    We describe our experience in using a software bus architecture (1,2) to build a fault location system from reusable software parts. The system consists of ‘‘plug compatible’’ software components connected by a software bus. This architecture makes it possible to assemble the system either as a collection of cooperating distributed processes, or as a single program running on a single

  8. Development of a Mode Choice Model for Bus Rapid Transit in Santa Clara County, CA

    Microsoft Academic Search

    Chun-Hung Peter Chen; George A. Naylor

    2011-01-01

    Bus Rapid Transit (BRT) is an enhanced bus service that offers many of the same service attributes as rail transit, such as specialized vehicles, large stations, real-time passenger information, and more frequent and reliable operations. The Santa Clara Valley Transportation Authority (VTA) intends to develop an integrated BRT network throughout Santa Clara County, California, to provide high quality service to

  9. Implementation of an Iterative Headway-based Bus Holding Strategy with Real-time Information

    E-print Network

    Adida, Elodie

    1 Implementation of an Iterative Headway-based Bus Holding Strategy with Real-time Information Qin and fast to implement, which makes it suitable for real-time implementation. The model is evaluated intervention, bus bunching was almost unavoidable regardless of the driver's or the passengers' behavior

  10. Application Research of Cooling Load of Bus Air Conditioning Based on BP Neutral Network

    Microsoft Academic Search

    Huifan Zheng; Caixia Zhu

    2008-01-01

    Introduces the development and application research of load about air- conditioning based on BP neutral network. Connects some theory about BP neutral network and characters about bus air conditioning, and develops BP neutral networks for cooling load calculation of bus air conditioning. The results show the cooling load decrease 22.8 percent compare with steady calculation method. The BP neutral network

  11. 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…

  12. 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…

  13. Research on Voltage Acquisition System Based on Modbus Industrial Bus and Single Chip

    Microsoft Academic Search

    Chen Lin

    2009-01-01

    The voltage acquisition system based on modbus industrial bus and single chip is designed and its prototype is also implemented. It consists of MCS51 single chip and multichannel voltage acquisition card. And the single chip communicates with the card through modbus industrial bus protocol, which collects, copes with and real-time display voltage related data. The system can be applied to

  14. Modeling and evaluation of a plug-in hybrid fuel cell shuttle bus

    Microsoft Academic Search

    C. S. Hearn; M. C. Lewis; R. C. Thompson; R. G. Longoria

    2009-01-01

    The Center for Electromechanics at The University of Texas at Austin acquired a plug-in hybrid fuel cell bus for demonstration and model development under a program funded through the USDOT-FTA. The purpose of this program was to evaluate the performance and use of the bus while developing a model that could predict overall performance and energy consumption on daily driving

  15. Research and development for the communication interface conversion of Profibus and CAN bus

    Microsoft Academic Search

    Xu Guangli; Zhang Hao

    2010-01-01

    Profibus, CAN bus are two kinds of industrial field bus, which account for 30% in the field of industrial control. At present fieldbus conversion products in the market only achieves the conversion between RS232 and RS485, which can no longer meet the needs of users. However, by comparing the OSI reference model Profibus, CAN communication model structure are found to

  16. 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.

  17. Optimization for the reliability of TTCAN bus based on Genetic Algorithms

    Microsoft Academic Search

    Xi Chen; Weijie Lv; Luyuan Liu

    2008-01-01

    TTCAN protocol reduces the jitter of message and makes full use of bandwidth by introducing time-trigger mode into CAN bus. On the other hand it reduces the reliability under electromagnetic interference (EMI). Conclusion is drawn that the performance and reliability canpsilat get the minimum value simultaneously in this paper. In order to improve the reliability of TTCAN bus under EMI,

  18. Early findings on the effects of deregulation of bus services in Scotland

    Microsoft Academic Search

    Peter J. Hills

    1991-01-01

    The 1985 Transport Act in the UK drastically changed the framework for the supply of local bus services. Its provisions, commonly described as “deregulation,” removed quantity control from local (formerly stage?carriage) bus services by abolishing Road Service Licences. Competitive tendering was also introduced for any service which a local authority wished to subsidise on the grounds of social need. In

  19. Rapid Communication The neural basis of the butcher-on-the-bus phenomenon

    E-print Network

    Paller, Ken

    the butcher on the bus. The context of the bus provides none of the clues concerning the butcher's identity, and recollection, remembering some informa- tion plus the spatiotemporal context of the episode in which that a person is familiar (often upon seeing their face in an atypical context) while failing to recall any

  20. Modal talk: Discourse analysis of how people talk about bus and car travel

    Microsoft Academic Search

    J. W. Guiver

    2007-01-01

    This paper presents the findings of discourse analysis of the transcripts of ten focus groups discussing bus and car travel. It finds that the modes are talked about in different ways: bus travel being referred to as a series of episodes mostly focussing on worst-case scenarios while car travel is represented as a more consistent commodity. Both modes exhibit different

  1. Study on Bus Route Evaluation System in Beijing Based on AHP

    Microsoft Academic Search

    Ailing Huang; Jinsheng Shen; Wei Guan

    2007-01-01

    Bus route evaluation (BRE) of the public transit system in Beijing is requisite decision to regulate existing bus routes and reallocate transit resources for sustain operation. Since there wasn't a systematic BRE system for Beijing, firstly, this paper develops comprehensive BRE standards according to the status quo of Beijing's transit system, which includes 3 categories, 20 criterions in total. Secondly,

  2. Use of the cars and bus at Conservation Biology 1/2 21/09/2010

    E-print Network

    Richner, Heinz

    Use of the cars and bus at Conservation Biology 1/2 21/09/2010 General rules: The following rules below. The organization and supervision of the Conservation Biology cars and bus is done by one as a car is borrowed by a student or any other collaborator of the division the main responsibility

  3. FPGA-BASED 3D GRAPHICS PROCESSOR WITH PCI-BUS INTERFACE, AN IMPLEMENTATION CASE

    E-print Network

    FPGA-BASED 3D GRAPHICS PROCESSOR WITH PCI-BUS INTERFACE, AN IMPLEMENTATION CASE STUDY Hans Holten Phone: +45 4525 3351 , Fax: +45 4593 0074 hahl@imm.dtu.dk ABSTRACT Case study of an FPGA implementation of a 3D graphics processor. Practical design issues dealing with a PCI-bus based reconfigurable FPGA

  4. 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…

  5. 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

    ...bus transportation miles for residential students? 39.711 Section 39.711 Indians...THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation Calculating Transportation...bus transportation miles for residential students? To calculate the total annual...

  6. 25 CFR 39.711 - How does a school calculate annual bus transportation miles for residential students?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...bus transportation miles for residential students? 39.711 Section 39.711 Indians...THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation Calculating Transportation...bus transportation miles for residential students? To calculate the total annual...

  7. 25 CFR 39.711 - How does a school calculate annual bus transportation miles for residential students?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...bus transportation miles for residential students? 39.711 Section 39.711 Indians...THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation Calculating Transportation...bus transportation miles for residential students? To calculate the total annual...

  8. 25 CFR 39.710 - How does a school calculate annual bus transportation miles for day students?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...annual bus transportation miles for day students? 39.710 Section 39.710 Indians...THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation Calculating Transportation...annual bus transportation miles for day students? To calculate the total annual...

  9. 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

    ...annual bus transportation miles for day students? 39.710 Section 39.710 Indians...THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation Calculating Transportation...annual bus transportation miles for day students? To calculate the total annual...

  10. 25 CFR 39.711 - How does a school calculate annual bus transportation miles for residential students?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...bus transportation miles for residential students? 39.711 Section 39.711 Indians...THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation Calculating Transportation...bus transportation miles for residential students? To calculate the total annual...

  11. 25 CFR 39.710 - How does a school calculate annual bus transportation miles for day students?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...annual bus transportation miles for day students? 39.710 Section 39.710 Indians...THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation Calculating Transportation...annual bus transportation miles for day students? To calculate the total annual...

  12. 25 CFR 39.710 - How does a school calculate annual bus transportation miles for day students?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...annual bus transportation miles for day students? 39.710 Section 39.710 Indians...THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation Calculating Transportation...annual bus transportation miles for day students? To calculate the total annual...

  13. 25 CFR 39.711 - How does a school calculate annual bus transportation miles for residential students?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...bus transportation miles for residential students? 39.711 Section 39.711 Indians...THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation Calculating Transportation...bus transportation miles for residential students? To calculate the total annual...

  14. 25 CFR 39.710 - How does a school calculate annual bus transportation miles for day students?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...annual bus transportation miles for day students? 39.710 Section 39.710 Indians...THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation Calculating Transportation...annual bus transportation miles for day students? To calculate the total annual...

  15. 49 CFR 37.169 - Interim requirements for over-the-road bus service operated by private entities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Interim requirements for over-the-road bus service operated by private entities... Interim requirements for over-the-road bus service operated by private entities...Private entities operating over-the-road buses, in addition to compliance...

  16. Bus passenger origin-destination estimation and travel behavior using automated data collection systems in London, UK

    E-print Network

    Wang, Wei, S.M. Massachusetts Institute of Technology

    2010-01-01

    This research explores the application of archived data from Automatic Data Collection Systems (ADCS) to transportation planning with a focus on bus passenger Origin-Destination (OD) inferences at the bus-route level and ...

  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. Contribution analysis of bus pass-by noise based on dynamic transfer path method

    NASA Astrophysics Data System (ADS)

    Liu, Haitao; Zheng, Sifa; Hao, Peng; Lian, Xiaomin

    2011-10-01

    Bus pass-by noise has become one of the main noise sources which seriously disturb the mental and physical health of urban residents. The key of reducing bus noise is to identify major noise source. In this paper the dynamic transfer characteristic model in the process of bus acceleration is established, which can quantitatively describe the relationship between the sound source or vibration source of the vehicle and the response points outside the vehicle; also a test method has been designed, which can quickly and easily identify the contribution of the bus pass-by noise. Experimental results show that the dynamic transfer characteristic model can identify the main noise source and their contribution during the acceleration, which has significance for the bus noise reduction.

  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 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.

  2. Size-and State-Aware Dispatching Problem with Queue-Specific Job Sizes Esa Hyytia, Aleksi Penttinen and Samuli Aalto

    E-print Network

    Hyytiä, Esa

    Size- and State-Aware Dispatching Problem with Queue-Specific Job Sizes Esa Hyyti¨a, Aleksi.lastname@tkk.fi Abstract We consider the dispatching problem in a size- and state-aware multi-queue system with Poisson arrivals and queue-specific job sizes. By size- and state-awareness, we mean that the dispatcher knows

  3. 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…

  4. The threat of punishment enforces peaceful cooperation and stabilizes queues in a coral-reef fish

    PubMed Central

    Wong, Marian Y.L; Buston, Peter M; Munday, Philip L; Jones, Geoffrey P

    2007-01-01

    Social queues, in which subordinates wait for their turn to inherit dominant breeding status, are a familiar feature of many animal societies. However, little is known about the mechanisms stabilizing social queues given the inevitable conflict over rank between group members. Here, we report the role of punishment and cooperation in promoting the stability of size-based queues in a coral-dwelling goby, Paragobiodon xanthosomus (Gobiidae). Quantitative analysis of the size-structure of queues revealed that individuals of adjacent rank differ in size by a specific size ratio, and comparisons of individual growth rates within queues demonstrated that specific size ratios are maintained over time via the regulation of subordinate growth rates. Furthermore, contest experiments demonstrated that the specific size ratio represents a threshold above which the subordinates become a threat to their immediate dominant, and as a result, dominants evict subordinates that exceed this size ratio from the group. We propose that threshold size ratios are maintained by subordinates as a form of peaceful cooperation whereby they avoid inflicting costs on dominants, and that such cooperation arises in response to the threat of punishment in the form of eviction by dominants. Societal stability is therefore achieved through the effects of punishment and cooperation acting in concert to promote the resolution of conflict over rank between group members. PMID:17301018

  5. 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.

  6. The HBus: A Media Acquisition Bus Optimized for Multiple Streams Jeffrey J. Wong, John A. Watlington, V. Michael Bove, Jr.

    E-print Network

    Bove Jr., V. Michael

    ­chained media acquisition system in which the analog/digital (A/D) converters are placed at the sources of transporting multiple media streams. The H­Bus is designed to allow the maximum possible number of uncorruptedThe H­Bus: A Media Acquisition Bus Optimized for Multiple Streams Jeffrey J. Wong, John A

  7. Volumel, Number6 OPERATIONSRESEARCHLETTERS December1982 THE MARSHALL AND STOYAN BOUNDS FOR IMRL/G/1 QUEUES ARE TIGHT

    E-print Network

    Whitt, Ward

    Consider the GI/G/i queue partially specified by the first two moments of the interarrival times a lower bound for EW which holds when the interarrival-time distribution is only NWUE (new worse than used-time distributions with the given moments. Thus, for IMRL/G/I queues with the first two moments oI the interarrival

  8. Scheme for Measuring Queueing Delay of a Router using Probe-Gap Model: The Single-Hop Case

    E-print Network

    Rojas-Cessa, Roberto

    Scheme for Measuring Queueing Delay of a Router using Probe-Gap Model: The Single-Hop Case to measure queueing delay of a router in a single-hop path. The proposed scheme is based on estimating the change of an intra- probe gap between a pair of probing packets after they traverse the router under test

  9. Hans Peter SchwefelTraffic Analysis II: MM3/4, LAQT, Fall05 Traffic Theory and Queueing Systems II

    E-print Network

    Schwefel, Hans-Peter

    / Stationarity Connection · Nonstationarity in traffic is primarily a result of varying human behavior over timePage 1 Hans Peter SchwefelTraffic Analysis II: MM3/4, LAQT, Fall05 Traffic Theory and Queueing-Peter Schwefel · Mm1 M/GI/1 and GI/M/1 Queues · Mm2 Correlated/Bursty Traffic Models, MMPPs · Mm3 Matrix

  10. Hans Peter SchwefelTraffic Analysis II: MM3/4, LAQT, Fall04 Traffic Theory and Queueing Systems II

    E-print Network

    Schwefel, Hans-Peter

    / Stationarity Connection · Nonstationarity in traffic is primarily a result of varying human behavior over timePage 1 Hans Peter SchwefelTraffic Analysis II: MM3/4, LAQT, Fall04 Traffic Theory and Queueing-Peter Schwefel · Mm1 M/GI/1 and GI/M/1 Queues · Mm2 Correlated/Bursty Traffic Models, MMPPs · Mm3 Long

  11. Folding Proteins at 500 ns/hour with Work Queue

    PubMed Central

    Abdul-Wahid, Badi’; Yu, Li; Rajan, Dinesh; Feng, Haoyun; Darve, Eric; Thain, Douglas; Izaguirre, Jesús A.

    2014-01-01

    Molecular modeling is a field that traditionally has large computational costs. Until recently, most simulation techniques relied on long trajectories, which inherently have poor scalability. A new class of methods is proposed that requires only a large number of short calculations, and for which minimal communication between computer nodes is required. We considered one of the more accurate variants called Accelerated Weighted Ensemble Dynamics (AWE) and for which distributed computing can be made efficient. We implemented AWE using the Work Queue framework for task management and applied it to an all atom protein model (Fip35 WW domain). We can run with excellent scalability by simultaneously utilizing heterogeneous resources from multiple computing platforms such as clouds (Amazon EC2, Microsoft Azure), dedicated clusters, grids, on multiple architectures (CPU/GPU, 32/64bit), and in a dynamic environment in which processes are regularly added or removed from the pool. This has allowed us to achieve an aggregate sampling rate of over 500 ns/hour. As a comparison, a single process typically achieves 0.1 ns/hour. PMID:25540799

  12. Priority queues with bursty arrivals of incoming tasks

    NASA Astrophysics Data System (ADS)

    Masuda, N.; Kim, J. S.; Kahng, B.

    2009-03-01

    Recently increased accessibility of large-scale digital records enables one to monitor human activities such as the interevent time distributions between two consecutive visits to a web portal by a single user, two consecutive emails sent out by a user, two consecutive library loans made by a single individual, etc. Interestingly, those distributions exhibit a universal behavior, D(?)˜?-? , where ? is the interevent time, and ??1 or 3/2 . The universal behaviors have been modeled via the waiting-time distribution of a task in the queue operating based on priority; the waiting time follows a power-law distribution Pw(?)˜?-? with either ?=1 or 3/2 depending on the detail of queuing dynamics. In these models, the number of incoming tasks in a unit time interval has been assumed to follow a Poisson-type distribution. For an email system, however, the number of emails delivered to a mail box in a unit time we measured follows a power-law distribution with general exponent ? . For this case, we obtain analytically the exponent ? , which is not necessarily 1 or 3/2 and takes nonuniversal values depending on ? . We develop the generating function formalism to obtain the exponent ? , which is distinct from the continuous time approximation used in the previous studies.

  13. 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.

  14. Controlling ill-behaved flows with active queue management in DiffServ networks

    NASA Astrophysics Data System (ADS)

    Shu, Yantai; Gao, Deyun; Yang, Oliver W. W.; Qi, Lantao

    2003-08-01

    In this paper, we propose a new active queue management mechanism called the RIO-SD (RED IN and OUT with Selective Dropping) to control ill-behaved flows in DiffServ networks. Under this scheme, core routers are not required to maintain per-flow state, and the ill-behaved flows can be identified based on the drop history of the "OUT-profile" virtual queue. Control is effected by placing two pre-filters in front of the "IN-profile" and "OUT-profile" virtual queues respectively. Simulation results indicate that our approach can also improve the performance of other normal flows. Our work demonstrates that our algorithm is robust and simple to use.

  15. Optimal Service Capacities in a Competitive Multiple-Server Queueing Environment

    NASA Astrophysics Data System (ADS)

    Ching, Wai-Ki; Choi, Sin-Man; Huang, Min

    The study of economic behavior of service providers in a competition environment is an important and interesting research issue. A two-server queueing model has been proposed in Kalai et al. [11] for this purpose. Their model aims at studying the role and impact of service capacity in capturing larger market share so as to maximize the long-run expected profit. They formulate the problem as a two-person strategic game and analyze the equilibrium solutions. The main aim of this paper is to extend the results of the two-server queueing model in [11] to the case of multiple servers. We will only focus on the case when the queueing system is stable.

  16. A Comparison of Linear and Mesh Topologies - DQDB and the Manhattan Street Network

    Microsoft Academic Search

    Nicholas F. Maxemchuk; Ram Krishnan

    1993-01-01

    The authors make a performance and reliability comparison of two networks that have been proposed for use as high-speed metropolitan area networks (MANs)-the Manhattan street network (MSNet) and the distributed queue dual bus (DQDB) network. Both networks use slotted access protocols and have the same number of links, transmitters, and receivers per node. The DQDB network has been adopted by

  17. DQDB\\/FBS: A fair MAC protocol stemming from DQDB fairness analysis

    Microsoft Academic Search

    M. Conti; E. Gregori; L. Lenzini

    1990-01-01

    DQDB (distributed queue dual bus) is a media access control (MAC) protocol which is being standardized in IEEE 802 as an 802.6 metropolitan area network (MAN) standard proposal. The authors analyze the major features responsible for unfairness in the DQDB MAC protocol with the bandwidth balancing mechanism disabled. For each of these factors mechanisms to reduce the unfairness are identified

  18. Distributed Floor Control Protocols for Computer Collaborative Applications on Overlay Networks

    E-print Network

    Banik, Shankar M.

    are gaining popularity among users who are geographically dispersed. Examples of these kinds of applications an implementation and evaluation of ALOHA and Distributed Queue Dual Bus (DQDB) distributed MAC (medium access of the proposed implementation of floor control protocols using an analytical model that is verified using

  19. 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…

  20. Solid state power bus controllers for aerospace applications 

    E-print Network

    Villarreal, Terry Joseph

    1988-01-01

    be improved by using faster devices and by using MOSFET's in place of BJT's. The final schematic is presented in the figure 2. 7. ~ al COC Nw Cnwl WW OI OCOOIA WC ~ OO AI ~ ~ WA ICI On COCCI Wl I o8 Cloit IIC bus I CF I ~ N RC ~ 4 CA CA N CA... command signai maintains an on state to the AC-SSPBC. When the TTL command instructs the AC-SSPBC to turn-oR', the current path i'rom the SCR to ground is opened by turning ofF transistor Q2 of figure 3. 4. When Q2 is turned ofF, the current through...

  1. Flexible Queue Scheduling Capabilities of the 1.3-m RCT: Application to Time Variable Sources

    NASA Astrophysics Data System (ADS)

    Carini, Michael T.; Gelderman, Richard; Davis, Donald R.; Engle, Scott G.; Guinan, Edward F.; McGruder, Charles H., III; Strolger, Louis-Gregory; Tedesco, Edward F.; Walter, Donald K.

    2011-03-01

    The queue scheduling capabilities of the RCT make it very suitable for routine monitoring of variable sources. The ease with which one can change observation priorities, parameters and add or subtract objects from the queue allow one to react quickly to sudden changes in source flux. The data archive process allows rapid access to the data for quick look analysis and source flux measurements. We describe the use of the RCT for optical variability monitoring of Blazars, in concert with observations at other wavelengths.

  2. Dual stage passive vibration isolation for optical interferometer missions

    NASA Astrophysics Data System (ADS)

    Bronowicki, Allen J.; MacDonald, Rhonda; Gürsel, Yekta; Goullioud, Renaud; Neville, Timothy; Platus, David L.

    2003-02-01

    Future space-based optical instruments such as the Space Interferometer Mission have vibration-induced error allocations at the levels of a few nano-meters and milli-arc-seconds. A dual stage passive isolation approach has been proposed using isolation first at the vibration-inducing reaction wheels, and a second isolation layer between the bus portion of the space vehicle (the backpack) and the optical payload. The development of the backpack isolator is described, with unit transmissibility results for individual isolator struts. The dual stage isolation approach is demonstrated on a dynamically feature-rich, 7-meter structural testbed (STB3). A new passive suspension that mitigates ground vibrations above 0.4 Hz has been integrated into the testbed. A series of OPD performance predictions have been made using measured transfer functions. These indicate that the 5-nm dynamic OPD allocation is within reach using the dual isolator approach. Demonstrating these low response levels in a noisy air environment has proven to be difficult. We are sequentially executing a plan to mitigate acoustic transmission between backpack and flight structure, as well as developing techniques to mitigate effects of background acoustic noise.

  3. A 32Gb\\/s On-Chip Bus With Driver Pre-Emphasis Signaling

    Microsoft Academic Search

    Liang Zhang; John M. Wilson; Rizwan Bashirullah; Lei Luo; Jian Xu; Paul D. Franzon

    2009-01-01

    This paper describes a differential current-mode bus architecture based on driver pre-emphasis for on-chip global interconnects that achieves high-data rates while reducing bus power dissipation and improving signal delay latency. The 16-b bus core fabricated in 0.25-mum complementary metal-oxide-semiconductor (CMOS) technology attains an aggregate signaling data rate of 32 Gb\\/s over 5-10-mm-long lossy interconnects. With a supply of 2.5 V,

  4. Connecticut Transit (CTTRANSIT) Fuel Cell Transit Bus: Third Evaluation Report and Appendices

    SciTech Connect

    Chandler, K.; Eudy, L.

    2010-01-01

    This report describes operations at Connecticut Transit (CTTRANSIT) in Hartford for one prototype fuel cell bus and three new diesel buses operating from the same location. The prototype fuel cell bus was manufactured by Van Hool and ISE Corp. and features an electric hybrid drive system with a UTC Power PureMotion 120 Fuel Cell Power System and ZEBRA batteries for energy storage. The fuel cell bus started operation in April 2007, and evaluation results through October 2009 are provided in this report.

  5. The prediction of bus arrival time using Automatic Vehicle Location Systems data

    E-print Network

    Jeong, Ran Hee

    2005-02-17

    their transit vehicles in real-time. The need for the model or technique to predict transit travel time using AVL data is increasing. While some research on this topic has been conducted, it has been shown that more research on this topic is required.... The objectives of this research were 1) to develop and apply a model to predict bus arrival time using AVL data, 2) to identify the prediction interval of bus arrival time and the probabilty of a bus being on time. In this research, the travel time prediction...

  6. Single Axis Attitude Control and DC Bus Regulation with Two Flywheels

    NASA Technical Reports Server (NTRS)

    Kascak, Peter E.; Jansen, Ralph H.; Kenny, Barbara; Dever, Timothy P.

    2002-01-01

    A computer simulation of a flywheel energy storage single axis attitude control system is described. The simulation models hardware which will be experimentally tested in the future. This hardware consists of two counter rotating flywheels mounted to an air table. The air table allows one axis of rotational motion. An inertia DC bus coordinator is set forth that allows the two control problems, bus regulation and attitude control, to be separated. Simulation results are presented with a previously derived flywheel bus regulator and a simple PID attitude controller.

  7. Dual-Earner Families.

    ERIC Educational Resources Information Center

    Aldous, Joan, Ed.

    1981-01-01

    Presents eight articles focused on dual-earner families in terms of career choices, family adjustment problems, role conflicts, marital relationships, housework activities, and preschool children's sex role identities. (HLM)

  8. The workload in the MAP\\/G\\/1 queue with state-dependent services:its application to a queue with preemptive resume priority

    Microsoft Academic Search

    Tetsuya Takine; T. Hasegawa

    1994-01-01

    In this paper, we consider the workload process in the MAP\\/G\\/1 queue with state-dependent service time distributions. The arrival process of customers is assumed to be a MAP(Markovian arrival process), which is a class of semi-Markovian arrival processes. The amount of work brought into the system upon arrival is distributed according to a general distribution which may depend on the

  9. SSMCB: Low-Power Variation-Tolerant Source-Synchronous Multicycle Bus

    Microsoft Academic Search

    Maged Ghoneima; Yehea Ismail; Muhammad Khellah; V. De

    2009-01-01

    In this paper, a variation-tolerant low-power source-synchronous multicycle bus (SSMCB) interconnect scheme is proposed. This scheme is scalable and suitable for transferring data across different clock domains such as those in \\

  10. 49 CFR 571.220 - Standard No. 220; School bus rollover protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...injuries that result from failure of the school bus body structure to withstand forces encountered in rollover crashes...sec2 is applied to the roof of the vehicle's body structure through a force application plate as specified in...

  11. NREL Showcases Hydrogen Internal Combustion Engine Bus, Helps DOE Set Standards for Outreach (Fact Sheet)

    SciTech Connect

    Not Available

    2010-11-01

    This fact sheet describes the National Renewable Energy Laboratory's (NREL's) accomplishments in showcasing a Ford hydrogen-powered internal combustion engine (H2ICE) bus at The Taste of Colorado festival in Denver. NREL started using its U.S. Department of Energy-funded H2ICE bus in May 2010 as the primary shuttle vehicle for VIP visitors, members of the media, and new employees. In September 2010, NREL featured the bus at The Taste of Colorado. This was the first major outreach event for the bus. NREL's educational brochure, vehicle wrap designs, and outreach efforts serve as a model for other organizations with DOE-funded H2ICE buses. Work was performed by the Hydrogen Education Group and Market Transformation Group in the Hydrogen Technologies and Systems Center.

  12. A 40 Gb/s Optical Bus for Optical Backplane Interconnections

    E-print Network

    Bamiedakis, Nikolaos; Hashim, Aeffendi; Penty, Richard V.; White, Ian H.

    2014-04-15

    -effectively integrated onto conventional printed circuit boards (PCBs). This paper presents the first optical backplane demonstrator based on the use of PCB-integrated polymer multimode waveguides and a regenerative shared bus architecture. The backplane demonstrator...

  13. Psychosocial Work Factors, Blood Pressure and Psychological Strain in Male Bus Operators

    PubMed Central

    CENDALES, Boris; USECHE, Sergio; GÓMEZ, Viviola

    2014-01-01

    The research aim was to predict the bus operators’ blood pressure (BP) and psychological strain using a combination of the Job-Demand Control (JDC) and Effort-Reward Imbalance (ERI) models. The study was conducted with a sample of 139 bus operators in the city of Bogotá (Colombia), who answered a questionnaire that included the Job Content Questionnaire (JCQ), the ERI Questionnaire, and the General Health Questionnaire (GHQ). Four consecutive BP readings taken in the workplace were averaged to calculate an estimation of the bus operators’ BP. By conducting multiple linear regressions it was found that, taken together, JDC and ERI models explain 10% (F(11,139)=2,502; p=0.00) of systolic BP variance, and 34% (F(6,139)=8,638; p=0.00) of psychological strain variance. These results suggest that the JDC and ERI predictors provide complementary information which increases the probability of accurately model the bus operators’ health. PMID:24869893

  14. [On road particle emission characteristics of a Chinese phase IV natural gas bus].

    PubMed

    Lou, Di-Ming; Cheng, Wei; Feng, Qian

    2014-03-01

    An on-road experimental research was made on a Chinese phase IV natural gas bus using a Portable Emission Measurement System (PEMS), and particle emission characteristics under different vehicle speed, acceleration and vehicle specific power were investigated. The results show that particle number and mass emission rates increase and their emission factors decrease while the speed of the bus rises. Particle number concentration of different sizes shows multimodal logarithmic distribution pattern when the bus runs on all operation conditions (idle, low speed, medium speed and high speed), and nucleation mode particle account for a large proportion in the total particle number. With the increase of acceleration, particle emission rate rises, and it is lower when the bus runs at constant speed or slow deceleration condition than that at the fast acceleration condition. Furthermore, particle emission rate increases against the absolute value of the vehicle specific power (VSP). PMID:24881371

  15. Design the developed bus parking area management solution based on fusion technology of things

    NASA Astrophysics Data System (ADS)

    Ge, Ying-long

    2013-07-01

    Taking advantage of the fusion technology of things this paper constructed a combination of hardware and software application, hardware's major function was to collect the bus behavior data of system needed, including basic data of driver and fare bag stored in moving passive RFID tag, and the information of running status of bus on each stage perceived by all kinds of sensors in the parking area. The information which was handled by the middleware was sent to data center. The program solved the problem on the monitoring of the behavior of the bus in the parking area, meanwhile, achieved the data sharing, so as to tackle the defects of the traditional bus parking area management system's non-automated data collection, non-real-time data presenting and poor data sharing.

  16. Psychosocial work factors, blood pressure and psychological strain in male bus operators.

    PubMed

    Cendales, Boris; Useche, Sergio; Gómez, Viviola

    2014-01-01

    The research aim was to predict the bus operators' blood pressure (BP) and psychological strain using a combination of the Job-Demand Control (JDC) and Effort-Reward Imbalance (ERI) models. The study was conducted with a sample of 139 bus operators in the city of Bogotá (Colombia), who answered a questionnaire that included the Job Content Questionnaire (JCQ), the ERI Questionnaire, and the General Health Questionnaire (GHQ). Four consecutive BP readings taken in the workplace were averaged to calculate an estimation of the bus operators' BP. By conducting multiple linear regressions it was found that, taken together, JDC and ERI models explain 10% (F(11,139)=2,502; p=0.00) of systolic BP variance, and 34% (F(6,139)=8,638; p=0.00) of psychological strain variance. These results suggest that the JDC and ERI predictors provide complementary information which increases the probability of accurately model the bus operators' health. PMID:24869893

  17. Semi-Detailed Bus Routing with Variation Reduction 600 W California Ave

    E-print Network

    Brayton, Robert K.

    Sunnyvale, CA 94086 1-408-215-6103 fanmo@synplicity.com Robert K. Brayton University of California 573 Cory Hall, UC Berkeley Berkeley, CA 94720 1-510-643-9801 brayton@eecs.berkeley.edu ABSTRACT A bus routing

  18. Queueing Analysis of Traffic Shaping and Scheduling Applied In The Source ATM End Point \\Lambda

    E-print Network

    László, Jereb

    , the AAL sends cells as soon as payloads are filled. In the message mode, the AAL accepts an entire packet is an undesirable side­effect of the interaction between traffic flows of random and dynamic nature due is terminated and presents a queueing model for the traffic control scheme. At the sender side ATM cell payloads

  19. Index Policies for a Multi-Class Queue with Convex Holding Cost and Abandonments

    E-print Network

    Ayesta, Urtzi

    Index Policies for a Multi-Class Queue with Convex Holding Cost and Abandonments M. Larra~naga1 good performance. Our index policy attributes to each class an index, which depends on the number of customers currently present in that class. The index values are ob- tained by solving a relaxed version

  20. Modeling the Performance and the Energy Usage of Wireless Sensor Networks by Retrial Queueing Systems

    E-print Network

    Sztrik, János

    Modeling the Performance and the Energy Usage of Wireless Sensor Networks by Retrial Queueing Systems Tamás Bérczes Faculty of Informatics, University of Debrecen 4032, Egyetem tér 1. Debrecen, Hungary berczes.tamas@inf.- unideb.hu Béla Almási Faculty of Informatics, University of Debrecen 4032

  1. Queueing Systems 34 (2000) 135 1 Performance analysis of a slotted-ALOHA protocol on a

    E-print Network

    Sharma, Vinod

    2000-01-01

    Queueing Systems 34 (2000) 1­35 1 Performance analysis of a slotted-ALOHA protocol on a capture 29 May 1999 We consider the slotted ALOHA protocol on a channel with a capture effect. There are M of our results and proofs will be shown to hold also for the slotted ALOHA protocol without capture

  2. Retrial queues with collision arising from unslottedCSMA\\/CD protocol

    Microsoft Academic Search

    Bong Dae Choi; Yang Woo Shin; Wi Chong Ahn

    1992-01-01

    We consider a retrial queueing model with collision arising from the specific communication protocolCSMAICD. Under the retrial control policy in which the retrial rate is inversely proportional to the number of customers in the retrial group, we derive the generating function of the limiting distribution of the number of customers in the retrial group at the moment when the channel

  3. Hierarchical Queue-Length-Aware Power Control for Real-Time Applications over

    E-print Network

    Wu, Dapeng Oliver

    Delay-constrained communications, power control, queuing theory, matrix-geometric method, ef- fective1 Hierarchical Queue-Length-Aware Power Control for Real-Time Applications over Wireless Networks guarantees for real-time applications over wireless networks. The power control laws that aim at optimizing

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

    E-print Network

    Sun, Feng

    2009-05-15

    to calculate 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...

  5. On packet marking at priority queues R. J. Gibbens and F. P. Kelly

    E-print Network

    Kelly, Frank

    concerns charging, rate control and routing for a communication network using priority mecha- nisms. Keywords|Congestion pricing, di#11;erentiated services, pri- ority queues, rate control, routing. I], [14], [17]) has stressed the importance of feed- back mechanisms based on explicit congestion signals

  6. On packet marking at priority queues R. J. Gibbens and F. P. Kelly

    E-print Network

    Kelly, Frank

    concerns charging, rate control and routing for a communication network using priority mecha- nisms. Keywords--Congestion pricing, differentiated services, pri- ority queues, rate control, routing. I], [17]) has stressed the importance of feed- back mechanisms based on explicit congestion signals [6

  7. 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

  8. International Scientific Conference Computer Science'2008 Simulation of Rare Event in Queueing Systems

    E-print Network

    Del Moral , Pierre

    International Scientific Conference Computer Science'2008 308 Simulation of Rare Event in Queueing of Rousse elena_pl@gbg.bg, dradev@abv.bg Abstract The paper is devoted on computer simulation of rare event probability, which is a critical issue in areas such as reliabilities, telecommunications, aircraft management

  9. Decomposition Algorithms for Analyzing Transient Phenomena in Multiclass Queueing Networks in Air Transportation

    Microsoft Academic Search

    MICHAEL D. PETERSON; DIMITRIS J. BERTSIMAS; AMEDEO R. ODONI

    1995-01-01

    A previous paper (1992) by the same authors studied the phenomenon of transient congestion in landings at an airport and developed a recursive approach for computing moments of queue lengths and waiting times. This paper extends our approach to a network, developing two approximations based on the prior method. Both approaches work by using delay information estimated at one location

  10. A robust detection method of vehicle queue and dissipation during evening rush hour

    Microsoft Academic Search

    Deliang Yang; Le Xin; Yangzhou Chen

    2011-01-01

    By vehicle presence detection and movement analysis on the monitored region based on video processing technology, a real-time robust detection method of vehicle queue and dissipation is proposed in this paper. With a duplex flexible window fused with the Haar feature based AdaBoost cascade classifiers, the method can efficiently track the position changes of the tail and head of a

  11. SUBMITTED TO IEEE INFOCOM 2003 1 Analysis of REDFamily Active Queue

    E-print Network

    Claypool, Mark

    traffic sources to reduce trans­ mission rate before the congested router queue overflows. Thus, when to achieve high link utilization with a low queuing delay. Recent studies show that RED is difficult to configure for some rapidly changing traffic mixes and loads [1]. Other studies show that under some condi

  12. Designing the Westercheldetunnel toll plaza using a combination of queueing and simulation

    Microsoft Academic Search

    Nico M. van Dijk; Mark D. Hermans; Maurice J. G. Teunisse; Henk Schuurman

    1999-01-01

    This paper describes how a combined queueing and simulation study was successfully executed for the design of a toll plaza. The objectives of the study were twofold: ? to configure the types of toll booths with multiple payment functionalities (cash, credit cards, and electronic payment). ? to determine the number of toll booths for each type. The model was also

  13. Designing the Westerscheldetunnel toll plaza using a combination of queueing and simulation

    Microsoft Academic Search

    Nico M. van Dijk; Mark D. Hermans; M. J. G. Teunisse; H. Schuurman

    1999-01-01

    This paper describes how a combined queueing and simulation study was successfully executed for the design of a toll plaza. The objectives of the study were twofold: to configure the types of toll booths with multiple payment functionalities (cash, credit cards, and electronic payment). To determine the number of toll booths for each type. The model was also used to

  14. QUEUEING ANALYSIS OF BUFFERED SWITCHING NETWORKS JONATHAN S. TURNER fellow, ieee

    E-print Network

    Turner, Jonathan S.

    networks. Our analysis explicitly models the state of an en- tire switch and infers information about. Such systems require an analysis which explicitly models the state of the entire switch rather than the statesQUEUEING ANALYSIS OF BUFFERED SWITCHING NETWORKS JONATHAN S. TURNER fellow, ieee Abstract

  15. On viterbi's formula for the mean delay in a queue of data packets

    Microsoft Academic Search

    Marcel F. NEUTS

    1990-01-01

    An explicit formula for the mean waiting time in a discrete-time queue whose input is generated by N heterogeneous two-state Markovian sources was obtained by A. M. Viterbi. We show that the same formula holds under more general conditions, provided that the terms involved are appropriately redefined. The method of proof exploits the structural features of the model, which may

  16. Joint Subcarrier and Power Allocation in Channel-Aware Queue-Aware Scheduling for Multiuser OFDM

    Microsoft Academic Search

    Chandrashekar Mohanram; Srikrishna Bhashyam

    2007-01-01

    In an Orthogonal Frequency Division Multiplexing (OFDM) downlink scenario, we propose joint subcarrier and power allocation for Channel-Aware Queue-Aware scheduling while allowing multiple users to share a single OFDM symbol. Our approach is to combine subcarrier and power allocation by optimizing a user's power allocation immediately after the user has been allocated a subcarrier. Simulation results show that joint subcarrier

  17. Cross-Layer Resource Allocation for Downlink Access Using Instantaneous Fading and Queue Length Information

    E-print Network

    Marques, Antonio Garcia

    --Cross-layer algorithms that jointly allocate re- sources at different layers are known to foster the communication] to derive resource allocation algorithms that optimize the system performance while guarantee the queues and rate loadings in every channel. The optimal cross-layer resource allocation (flows, powers, rates

  18. Large Deviations and Overflow Probabilities for the General Single-Server Queue, With Applications

    Microsoft Academic Search

    N. g. Duffield; Neil Connell

    1994-01-01

    We consider from a thermodynamic viewpoint queueing systems where the workloadprocess is assumed to have an associated large deviation principle with arbitraryscaling: there exist increasing scaling functions (a t ; v t ; t 2R+ ) and a rate function Isuch that if (W t ; t 2 R+ ) denotes the workload process, thenlimt!1v\\\\Gamma1t log P (W t =a

  19. The Effect of Multiple Time Scales and Subexponentiality in MPEG Video Streams on Queueing Behavior

    Microsoft Academic Search

    Predrag R. Jelenkovic; Aurel A. Lazar; Nemo Semret

    1997-01-01

    Guided by the empirical observation that real- time MPEG video streams exhibit both multiple time scale and subexponential characteristics, we construct a video model that captures both of these characteristics and is amenable to queueing analysis. We investigate two fundamental approaches for extract- ing the model parameters: using sample path and second-order statistics-based methods. The model exhibits the following two

  20. In Proceedings of IEEE INFOCOM'93 RateControlled StaticPriority Queueing \\Lambda

    E-print Network

    Zhang, Hui

    Static­Priority (RCSP) queueing discipline, that can provide throughput, delay, delay jitter, and loss with performance guarantees expressed in terms of delay, delay jitter, throughput and loss rate bounds. It has been version [15], Jit­ ter Earliest­Due­Date (Jitter­EDD) [18], Stop­and­Go [10], and Hierarchical Round Robin

  1. 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 Joseph A. Kaplan (j.a.kaplan@larc.nasa.gov) Michael L. Nelson (m.l.nelson@larc.nasa.gov) NASA Langley" and the expectations of its functionality are the focus of this report. #12;NASA TM 109025 (Revision 1) - 2

  2. Joint Power and Secret Key Queue Management for Delay Limited Secure Communication

    E-print Network

    Koksal, Can Emre

    information using the binning techniques inspired by the wiretap channel fails to secure the information. This work can be viewed as a first step in providing a framework that combines both information theory and queueing analysis for the study of information theoretic security. I. INTRODUCTION Secure communication

  3. A queueing model of pilot decision making in a multi-task flight management situation

    NASA Technical Reports Server (NTRS)

    Walden, R. S.; Rouse, W. B.

    1977-01-01

    Allocation of decision making responsibility between pilot and computer is considered and a flight management task, designed for the study of pilot-computer interaction, is discussed. A queueing theory model of pilot decision making in this multi-task, control and monitoring situation is presented. An experimental investigation of pilot decision making and the resulting model parameters are discussed.

  4. A Queueing Network Analysis of Computer Communication Networks with Window Flow Control

    Microsoft Academic Search

    MARTIN REISER

    1979-01-01

    A computer communication network with window flow control is modeled by a closed multichain queueing network. The severe computational limitation of previous solution algorithms is overcome with a heuristic derived from the recently found mean value analysis. A large numerical example is given.

  5. Message Queueing Analysis in Wireless Networks with Mobile Station Failures and Handoffs

    E-print Network

    Lyu, Michael R.

    in mobile wireless environments while maintain- ing network connections by a wireless interface. The AP, no computational messages can be transmitted between the APs and the MS. 1 #12;Wireless computing enables usersMessage Queueing Analysis in Wireless Networks with Mobile Station Failures and Handoffs Xinyu Chen

  6. 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

  7. Maximum Queue Length of a Fluid Model with a Gaussian Input

    E-print Network

    Jin, Yasong

    2007-12-11

    A fractional Brownian queueing model, that is, a fluid model with an input of a fractional Brownian motion, was proposed in the 1990s to capture the self-similarity and long-range dependence observed in Internet traffic. Since then, a Gaussian...

  8. 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.

  9. DYNAMIC MODEL OF NETWORK WITH REAL TIME TRAFFIC INFORMATION: QUEUE EQUILIBRIUM AND STABILITY ANALYSIS

    Microsoft Academic Search

    LEONID ENGELSON

    This paper proposes an analytical method for stability analysis of traffic flows in a traffic network with an advanced traveller information system. The presented model describes within-day development of queues when drivers affected by real-time traffic information choose their paths en route. The model reduces to a system of differential equations with delays and discontinuous right hand sides. Equilibrium points

  10. Experimental Evaluation of Variance Reduction Techniques for Queueing Simulation Using Generalized Concomitant Variables

    Microsoft Academic Search

    J. R. Wilson; A. A. B. Pritsker

    1984-01-01

    In a companion paper we developed a unified scheme for using poststratified sampling and control variables to improve the efficiency of regenerative queueing simulations. We adapted these variance reduction techniques to the estimation methods of replication analysis and regenerative analysis by exploiting the asymptotic joint normality of certain standardized concomitant variables that are defined on each input process sampled during

  11. CSC 1351: Computer Science -II, Fall-2012 (Object Oriented Programming and Data Structures -stacks, queues, trees)

    E-print Network

    Kundu, Sukhamay

    - stacks, queues, trees) FACULTY: Dr. S. Kundu 3117B PTH Off. Hrs: 12:00-13:20 TT, 3117B PTH (kundu@csc.lsu.edu) 8-2246 Lecture: 13:30-14:50 MW, 220 Tureaud (2150 PTH) GRADER: Forrest Osterman 164E Coates Off. Hrs

  12. RATE CONSERVATION LAWS FOR MULTIDIMENSIONAL PROCESSES OF BOUNDED VARIATION WITH APPLICATIONS TO PRIORITY QUEUEING

    E-print Network

    Guillemin, Fabrice

    RATE CONSERVATION LAWS FOR MULTIDIMENSIONAL PROCESSES OF BOUNDED VARIATION WITH APPLICATIONS a multidimensional version of the Rate Conservation Law (RCL) for c`adl`ag processes of bounded variation, such as priority queues. In particular the RCL is used to establish certain conservation laws between the idle

  13. RTS2: meta-queues scheduling and its realisation for FLWO 1.2m telescope

    NASA Astrophysics Data System (ADS)

    Kubánek, Petr; Falco, Emilio; Jelínek, Martin; Prouza, Michael; Štrobl, Jan; Fuchs, Martin; Gorosabel, Javier

    2012-09-01

    RTS2, or Remote Telescope System 2nd Version, is an open-source, distributed and modular observatory control system. During the course of its development lasting over a decade, the original goal to develop software capable of searches for optical transients of ?-ray bursts changed to develop a system for full control of large observatories executing complex observing scenarios. In this presentation, we would like to share our experience with meta-queues scheduling, developed primarily for automation of the FLWO 1.2m telescope. Meta-queues scheduling allows observers to quickly build and com- bine dierent observational scenarios, while still retaining ToO and weather interruption capabilities. Thanks to the queues and scheduling graphical user interface, observers can use the system without the need to under- stand complex functions used in the traditional merit function scheduling. By combining meta-queues and merit function scheduling, observatories can oer dierent options to schedule their observations to their users, so the acquired data will match the observers' expectations.

  14. Steady State Rare Events Simulation in Queueing Models and its Complexity Properties

    Microsoft Academic Search

    Søren Asmussen; Reuven Y. Rubinstein

    1995-01-01

    This paper gives an overview of rare events simulation via importance sampling in queueing models, as well as some new results and proofs in the area. Special attention is given to complexity properties of the estimators, exponential change of measure, steady-state implementation via Siegmund duality, and robustness under perturbation of the optimal set of parameters. Open problems and further research

  15. ANALYSIS OF THE WEIGHTED FAIR QUEUEING SYSTEM WITH TWO CLASSES OF CUSTOMERS WITH EXPONENTIAL SERVICE TIMES

    E-print Network

    Guillemin, Fabrice

    service times and by Boxma and Cohen [5] for Poisson arrivals and general service time distributions of a weighted fair queueing (WFQ) system with two classes of customers arriving according to Poisson processes plane can be reduced to a Poisson equation. The explicit formulas are then used to derive some

  16. Seeing Through Black Boxes : Tracking Transactions through Queues under Monitoring Resource Constraints6

    E-print Network

    Anandkumar, Animashree

    but are not available without proper instrumentation. Given an instrumentation budget, only a subset of queues can using timestamps. The goal is then to optimally allocate the instrumentation budget to maximize institutions and virtual retailers. The scope of transaction processing has widened to incorporate multiple

  17. A charge-transfer amplifier and an encoded-bus architecture for low-power SRAM's

    Microsoft Academic Search

    Shoichiro Kawashima; Toshihiko Mori; Ryuhei Sasagawa; Makoto Hamaminato; Shigetoshi Wakayama; Kazuo Sukegawa; Isao Fukushi

    1998-01-01

    This paper proposes and reports a low-power SRAM using a charge-transfer (CT) pre-sense amplifier and a bus signal encoding scheme. The CT amplifier overcomes the Vth relative difference between the pair MOS transistors, and thus reduces the input offset voltage. The encoded-bus scheme reduces the number of signals being switched to cut the capacitive load. These read-path dynamic circuits have

  18. DEVELOPMENT OF LINUX-BASED IOC WITH A VME-BUS COMPUTER

    Microsoft Academic Search

    Guobao ShenA; Junichi Odagiri; Tadahiko Katoh; Susumu Yoshida; Makoto Takagi

    EPICS is a control software tool-kit used to develop control systems for accelerators and experiments. The original EPICS assumes the use of VME-bus computers, and a commercial license of a real-time operating system (VxWorks). However, recent EPICS versions (after 3.14) allow the use of Linux instead of VxWorks. Intel-based single-board computers with a VME-bus have been available on the commercial

  19. City-Bus Network Control System and Its Key Technologies in Development

    Microsoft Academic Search

    Jian Hu; Gangyan Li

    2006-01-01

    Developing intelligent city public traffic is the most efficient method to solve city traffic problem. As the main public transportation vehicle of city public traffic, city-bus must fulfill several requests in terms of technologies. CBNCS (city-bus network control system) contains three technical aspects, i.e. vehicle electronic technology, vehicular network technology and intelligent control technology. In this paper, we firstly defined

  20. BSS: A Distributed Top-k Processing in Mobile BusNet for Security Surveillance

    Microsoft Academic Search

    Xu Li; Jiajun Hu; Hongyu Huang; Jialiang Lu; Wei Shu; Minglu Li; Min-You Wu

    2010-01-01

    We consider distributed top-k processing problem in a mobile scenario. Specially, we focus on a real application of a bus network (N nodes), where buses are equipped with cameras for real-time security surveillance. Due to the limited number of screens (k, k<;<;N) at the traffic management center, how to select k bus nodes with most passengers to upload image data

  1. New approaches to interfacing thermoelectric generators to the load bus in a nuclear space vehicle

    E-print Network

    Brohlin, Paul LeRoy

    1988-01-01

    NEW APPROACHES TO INTERFACING THERMOELECTRIC GENERATORS TO THE LOAD BUS IN A NUCLEAR SPACE VEHICLE A Thesis PAUL LEROY BROHLIN Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE December 1988 Major Subject: Electrical Engineering NEW APPROACHES TO INTERFACING THERMOELECTRIC GENERATORS TO THE LOAD BUS IN A NUCLEAR SPACE VEHICLE A Thesis PAUL LEROY BROHLIN Approved as to style and content by...

  2. A One-driver-multi-card High-accuracy Signal Acquisition System Based on PCI Bus

    Microsoft Academic Search

    Wang Lipeng; Wang Junzheng; Shen Wei

    2011-01-01

    This paper aims at increasing the accuracy of the signal acquisition system and decreasing the non-linear error of the A\\/D conversion. A multi-channel high-accuracy signal acquisition card based on PCI bus is designed and a Windows Driver Model (WDM) driver for multiple cards with same configuration is described. The local bus of the card is controlled by the temporal logic

  3. Effective regenerative braking control for smooth stop of a hybrid electric bus

    Microsoft Academic Search

    Jie Shu; Weiwei Xiong; Chengliang Yin; Yong Zhang

    2008-01-01

    Regenerative braking is an important function for a hybrid electric bus with many stop-to-go drive conditions. Yet an accurate nonlinear model for the composite brake system in HEV and a nonlinear model-based control design for a series-parallel hybrid electric bus have not been fully studied. This paper describes the brake system with regenerative braking function, and a special brake pedal

  4. Data collection plan for Phase 2 Alternative Fuels Bus Data Collection Program. Final report

    SciTech Connect

    Krenelka, T. [Battelle Columbus Labs., OH (United States)] [Battelle Columbus Labs., OH (United States)

    1993-07-01

    This document constitutes the plan for collecting and reporting data associated with a special set of transit bus demonstrations to be conducted under the Urban Bus Program of the Alternative Motor Fuels Act (AMFA) of 1988. This program, called the Phase 2 Bus Data Collection Program, serves as an adjunct to the Phase I Bus Data Collection Program, collecting detailed data on just a few buses to augment and enhance the Phase 1 data in fulfilling the urban bus requirements of AMFA. Demonstrations will be conducted at a few transit system locations throughout the US and will use alternative fuels and associated technologies to reduce undesirable transit bus exhaust emissions. Several organizations will be involved in the data collection; NREL will manage the program, analyze and store vehicle data, and make these data available through the Alternative Fuels Data Center. This information will enable transit agencies, equipment manufacturers, fuel suppliers, and government policy makers to make informed decisions about buying and using alternative fuels.

  5. Research development and demonstration of a fuel cell/battery powered bus system

    NASA Astrophysics Data System (ADS)

    Romano, S.; Wimmer, R.

    1993-02-01

    During 1992, the design of the three test bed buses evolved. Georgetown participated in all the working meetings and the preliminary design review of the Test Bed Bus (TBB). Throughout the Year, Georgetown provided input on system design and integration issues, transit industry requirements, and bus performance. GU also attended technical seminars, presenting papers at two. The computer simulation 'HYBRID', developed by Georgetown, was used to assess performance of different bus designs and system control algorithms. GU also modified the simulation to be more flexible and allow easier evaluation of designs. Georgetown had Exhibitgroup design and construct, to our specifications, a fuel cell bus display with a 1/10 scale model of the TBB for use at trade shows and exhibits. Energy Partners of West Palm Beach, Florida completed their subcontract for the engineering design study of a hydrogen fueled, fuel-cell-powered multi-passenger vehicle. Georgetown performed a study to determine the size of the US bus fleet and expected new bus deliveries over the next 10 years. Trojan Battery Company of Santa Fe Springs, California conducted a study to determine the specific design characteristics required of a lead acid battery to meet the special requirements posed by hybrid vehicle operation. Finally, GU assisted the prime contractor with the design of the system controller and its control algorithms.

  6. Exact and Metaheuristic Approaches for a Bi-Objective School Bus Scheduling Problem

    PubMed Central

    Chen, Xiaopan; Kong, Yunfeng; Dang, Lanxue; Hou, Yane; Ye, Xinyue

    2015-01-01

    As a class of hard combinatorial optimization problems, the school bus routing problem has received considerable attention in the last decades. For a multi-school system, given the bus trips for each school, the school bus scheduling problem aims at optimizing bus schedules to serve all the trips within the school time windows. In this paper, we propose two approaches for solving the bi-objective school bus scheduling problem: an exact method of mixed integer programming (MIP) and a metaheuristic method which combines simulated annealing with local search. We develop MIP formulations for homogenous and heterogeneous fleet problems respectively and solve the models by MIP solver CPLEX. The bus type-based formulation for heterogeneous fleet problem reduces the model complexity in terms of the number of decision variables and constraints. The metaheuristic method is a two-stage framework for minimizing the number of buses to be used as well as the total travel distance of buses. We evaluate the proposed MIP and the metaheuristic method on two benchmark datasets, showing that on both instances, our metaheuristic method significantly outperforms the respective state-of-the-art methods. PMID:26176764

  7. Composite Bus Structure for the SMEX/WIRE Satellite

    NASA Technical Reports Server (NTRS)

    Rosanova, Giulio G.

    1998-01-01

    In an effort to reduce the weight and optimize the structural design of the Small Explorer (SMEX) Wide-Field Infrared Explorer (WIRE) spacecraft, it has become desirable to change the material and construction from mechanically fastened aluminum structure to a fully bonded fiber-reinforced composite (FRC) structure. GSFC has developed the WIRE spacecraft structural bus design concept, including the instrument and launch vehicle requirements. The WIRE Satellite is the fifth of a series of SMEX satellites to be launched once per year. GSFC has chosen Composite Optics Inc. (COI) as the prime contractor for the development and procurement of the WIRE composite structure. The detailed design of the fully bonded FRC structure is based on COI's Short Notice Accelerated Production SATellite ("SNAPSAT") approach. SNAPSAT is a state of the art design and manufacturing technology for advanced composite materials which utilizes flat-stock detail parts bonded together to produce a final structural assembly. The structural design approach adopted for the WIRE structure provides a very viable alternative to both traditional aluminum construction as well as high tech. molded type composite structures. This approach to composite structure design is much less costly than molded or honeycomb sandwich type composite construction, but may cost slightly more than conventional aluminum construction on the subsystem level. However on the overall program level the weight saving achieved is very cost effective, since the primary objective is to allocate more mass for science payloads.

  8. An evaluation of comfort of a bus seat.

    PubMed

    Jianghong, Z; Long, T

    1994-12-01

    The aim of this research was to evaluate the comfort of a passenger seat for a new type of bus. A fuzzy set model of a multistage comfort scale (MCS) was adopted for the assessment of comfort, together with the techniques of human back shape and EMG measurements as well as posture analysis. The subjects were 30 university students. It is concluded that MCS is a rapid but comprehensive evaluation method for single chair evaluation. The overall rating of MCS is 0.532, which is acceptable under the conditions of the prototype evaluation. The seat profile fits better with the back curve of subjects who had higher comfort rating in the way that the upper profile of the seat coincides with the human back curve and the lower part of the profile intersects the human back curve in the lumbar region; here the human back curves were measured in the slumped sitting posture. There was a significant difference in the EMGs of back muscles between the two sitting postures (sitting upright and the slumped sitting posture) at all the seat heights. PMID:15676991

  9. Blood pressure and blood lead concentration in bus drivers

    SciTech Connect

    Sharp, D.S.; Osterloh, J.; Becker, C.E.; Bernard, B.; Smith, A.H.; Fisher, J.M.; Syme, S.L.; Holman, B.L.; Johnston, T.

    1988-06-01

    San Francisco bus drivers have an increased prevalence of hypertension. This study examined relationships between blood lead concentration and blood pressure in 342 drivers. The analysis reported in this study was limited to subjects not on treatment for hypertension (n = 288). Systolic and diastolic pressure varied from 102 to 173 mm Hg and from 61 to 105 mm Hg, respectively. The blood lead concentration varied from 2 to 15 ..mu..g/dL. The relationship between blood pressure and the logarithm of blood lead concentration was examined using multiple regression analysis. Covariates included age, body mass index, sex, race, and caffeine intake. The largest regression coefficient relating systolic blood pressure and blood lead concentration was 1.8 mm Hg/ln (..mu..g/dL). The coefficient for diastolic blood pressure was 2.5 mm Hg/ln (..mu..g/dL). These findings suggest effects of lead exposure at lower blood lead concentrations than those concentrations that have previously been linked with increases in blood pressure.

  10. Oxygen Generation System Laptop Bus Controller Flight Software

    NASA Technical Reports Server (NTRS)

    Rowe, Chad; Panter, Donna

    2009-01-01

    The Oxygen Generation System Laptop Bus Controller Flight Software was developed to allow the International Space Station (ISS) program to activate specific components of the Oxygen Generation System (OGS) to perform a checkout of key hardware operation in a microgravity environment, as well as to perform preventative maintenance operations of system valves during a long period of what would otherwise be hardware dormancy. The software provides direct connectivity to the OGS Firmware Controller with pre-programmed tasks operated by on-orbit astronauts to exercise OGS valves and motors. The software is used to manipulate the pump, separator, and valves to alleviate the concerns of hardware problems due to long-term inactivity and to allow for operational verification of microgravity-sensitive components early enough so that, if problems are found, they can be addressed before the hardware is required for operation on-orbit. The decision was made to use existing on-orbit IBM ThinkPad A31p laptops and MIL-STD-1553B interface cards as the hardware configuration. The software at the time of this reporting was developed and tested for use under the Windows 2000 Professional operating system to ensure compatibility with the existing on-orbit computer systems.

  11. Dual-modality imaging

    NASA Astrophysics Data System (ADS)

    Hasegawa, Bruce; Tang, H. Roger; Da Silva, Angela J.; Wong, Kenneth H.; Iwata, Koji; Wu, Max C.

    2001-09-01

    In comparison to conventional medical imaging techniques, dual-modality imaging offers the advantage of correlating anatomical information from X-ray computed tomography (CT) with functional measurements from single-photon emission computed tomography (SPECT) or with positron emission tomography (PET). The combined X-ray/radionuclide images from dual-modality imaging can help the clinician to differentiate disease from normal uptake of radiopharmaceuticals, and to improve diagnosis and staging of disease. In addition, phantom and animal studies have demonstrated that a priori structural information from CT can be used to improve quantification of tissue uptake and organ function by correcting the radionuclide data for errors due to photon attenuation, partial volume effects, scatter radiation, and other physical effects. Dual-modality imaging therefore is emerging as a method of improving the visual quality and the quantitative accuracy of radionuclide imaging for diagnosis of patients with cancer and heart disease.

  12. Approximate analysis of a fault-tolerant join-the-shortest-queue policy Guangzhi Li Gianfranco Ciardo

    E-print Network

    Ciardo, Gianfranco

    Ciardo Department of Computer Science College of William and Mary Williamsburg, VA 23187-8795, USA {gli, ciardo}@cs.wm.edu Abstract In distributed or multi-processor systems, the join the shortest queue (JSQ

  13. Dual mode heat exchanger

    NASA Astrophysics Data System (ADS)

    Altoz, F. E.

    1985-12-01

    The invention comprises a compact, light weight, dual mode heat transfer device. The dual mode heat transfer device provides for air cooling of heat dissipating electronic components at moderate aircraft speeds and when available ambient air is below a preselected temperature. At elevated aircraft speeds when the ambient air temperature is above the preselected temperature a coolant liquid is converted to steam or vapor in order to cool the heat dissipating electronic components. A preferred embodiment of the invention includes a cold plate for conducting heat away from the heat dissipating components and radiator fins for dissipating cold plate heat to a air cooling flow.

  14. Modeling Decisions for the Time-Dependent Optimal Lane Configuration Policy with Queueing Theory and Mathematical Programming

    Microsoft Academic Search

    Seongmoon Kim

    2007-01-01

    We provide mathematical models to operate a toll plaza with the time-dependent lane configuration policy. To formulate toll\\u000a operations in the problem we use the queueing theory and mathematical programming. The queueing theory is utilized to obtain\\u000a the stability condition which requires the mean arrival rate less than the mean service rate in each lane and compute the\\u000a mean waiting

  15. A note on comparing response times in the M/GI/1/FB and M/GI/1/PS queues

    E-print Network

    A note on comparing response times in the M/GI/1/FB and M/GI/1/PS queues Adam Wierman 1 Nikhil of job sizes are Processor Sharing (PS) and Feedback (FB). While a lot of work has been done on comparing the overall mean response time (a.k.a. sojourn time) of the PS and FB queues under an M/GI/1 system. We show

  16. Research, development and demonstration of a fuel cell/battery powered bus system. Phase 1, Final report

    SciTech Connect

    NONE

    1990-02-28

    Purpose of the Phase I effort was to demonstrate feasibility of the fuel cell/battery system for powering a small bus (under 30 ft or 9 m) on an urban bus route. A brassboard powerplant was specified, designed, fabricated, and tested to demonstrate feasibility in the laboratory. The proof-of-concept bus, with a powerplant scaled up from the brassboard, will be demonstrated under Phase II.

  17. Self-dual bent functions

    Microsoft Academic Search

    Claude Carlet; Lars Eirik Danielsen; Matthew G. Parker; Patrick Sole

    2010-01-01

    A bent function is called self-dual if it is equal to its dual. It is called anti-self-dual if it is equal to the complement of its dual. A spectral characterization in terms of the Rayleigh quotient of the Sylvester Hadamard matrix is derived. Bounds on the Rayleigh quotient are given for Boolean functions in an odd number of variables. An

  18. The ACP (Advanced Computer Program) Branch bus and real-time applications of the ACP multiprocessor system

    SciTech Connect

    Hance, R.; Areti, H.; Atac, R.; Biel, J.; Cook, A.; Fischler, M.; Gaines, I.; Husby, D.; Nash, T.; Zmuda, T.

    1987-05-08

    The ACP Branchbus, a high speed differential bus for data movement in multiprocessing and data acquisition environments, is described. This bus was designed as the central bus in the ACP multiprocessing system. In its full implementation with 16 branches and a bus switch, it will handle data rates of 160 MByte/sec and allow reliable data transmission over inter rack distances. We also summarize applications of the ACP system in experimental data acquisition, triggering and monitoring, with special attention paid to FASTBUS environments.

  19. New Dual Quark Models

    Microsoft Academic Search

    K. Bardakci; M. B. Halpern

    1971-01-01

    On the basis of new representations of the projective group, we construct some new dual quark models whose spin and internal symmetry are not multiplicative. One model is a factorized theory of exotic states with broken exchange degeneracy, ninth mesons being optional. The exotic states are suppressed three units below the Pomeranchon. In another model, with spin-orbit coupling and curved

  20. The capacity of two neighbour intersections considering the influence of the bus stop

    NASA Astrophysics Data System (ADS)

    Zhao, Xiao-mei; Gao, Zi-you; Li, Ke-ping

    2008-07-01

    In this paper, we use a two-lane CA model to investigate the effect of a bus stop between two neighbouring intersections on the capacity of the bus. Both the case of a bus stop with a special stopping lane and that of one without are considered. The capacity versus the distance LB( LD) between the stop and the upstream (downstream) intersection is studied, with respect to the entering probability Pe and the traffic light cycle T. It is found that a bus stop near an intersection can act as a bottleneck and cause a drop in the capacity when the LB (or LD) is below a critical point L(or L). However, the situation when the stop is located near the downstream intersection is worse than that of the upstream one. Furthermore, the simulation results show that the negative effect varies with the increase of the cycle time T and the capacity can be maximized by adjusting T. Comparisons between the two cases suggest that the stopping lane can improve the capacity to some extent. These results mean that the capacity can be exploited by changing the position of the bus stop or the cycle time, and adding a stopping lane if necessary. These findings may be useful in offering scientific guidance for the management and design of traffic networks.