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1

Waiting time analysis of the multiple priority dual queue with a preemptive priority service discipline  

Microsoft Academic Search

Abstract The dual queue consists of two queues, called the primary queue and the secondary queue. There is a single server in the primary queue but the secondary,queue has no service facility and only serves as a holding queue for the overloaded primary,queue. The dual queue has the additional feature of a priority scheme,to help reduce congestion. Two classes of

Panlop Zeephongsekul; Anthony Bedford

2006-01-01

2

Stochastics and Statistics Waiting time analysis of the multiple priority dual queue with a preemptive priority service discipline  

Microsoft Academic Search

The dual queue consists of two queues, called the primary queue and the secondary queue. There is a single server in the primary queue but the secondary queue has no service facility and only serves as a holding queue for the overloaded primary queue. The dual queue has the additional feature of a priority scheme to help reduce congestion. Two

P. Zeephongsekul; A. Bedford

3

On the efficiency of slot reuse in the dual bus configuration  

Microsoft Academic Search

Slot reuse is a simple method to improve the efficiency of MACs designed for the slotted, dual bus configuration. The authors propose several schemes for the assignment of throughput to stations in this configuration, taking into account slot reuse and assuming uniform traffic. The criteria for comparison of the schemes are throughput gain, worst message queueing and access delays at

Oran Sharon; Adrian Segall

1994-01-01

4

Dual bus local area network interfacing system  

US Patent & Trademark Office Database

An improved local area network interfacing system. The inventive system includes a frontplane circuit for connecting the interfacing system to a local area network and a backplane circuit for connecting the interfacing system to a host. A first internal bus is included for providing communication between the backplane circuit and the frontplane circuit. A processor is included for controlling the operation of the interfacing system. A second internal bus is included for providing communication between the processor and associated memory. An internal bus control circuit facilitates and controls communication between the first internal bus and the second internal bus. The dual internal busses of interfacing system of the present invention afford high speed operation with an inexpensive processor by allowing for input and output operations to be completed without being impeded by processor operations.

1994-10-11

5

CNG-dual fuel operation of an urban bus  

SciTech Connect

The dual-fuel operation of a Melbourne urban bus, with turbocharged diesel engine, using CNG is investigated. Extensive instrumented engine testing established the upper limit to diesel fuel substitution at 90%. Low load substitution operation exhibits efficiency loss and indicates the control profile for good efficiency. Operational analysis of bus duty and economic analysis indicate large savings by dual fuel operation. The pilot bus conversion is described.

Milkins, E.

1983-11-01

6

Dual-fuel school bus demonstration. Final report  

SciTech Connect

Three New York State school districts participated in the demonstration project by converting ten buses each to dual-fuel capability. The buses could use both CNG and gasoline or CNG and diesel fuel. Each district also installed a CNG refueling station to serve their buses. School bus fleets were chosen because of their large fuel use, advantageous usage patterns and the benefits that would accure from reduced fuel costs. The report includes both quantitative and qualitative data summarizing bus fuel economy; bus maintenance costs; regulatory problems; safety; training and community acceptance.

Not Available

1986-10-01

7

Dual-fuel school bus demonstration: Final report  

SciTech Connect

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

Not Available

1986-10-01

8

An efficient synchronization method for dual bus networks  

Microsoft Academic Search

The problem of the loss of synchronization in high-speed dual-bus MANs or LANs (metropolitan or local area networks) is considered, and an efficient method to recover alignment is proposed. The proposed mechanism provides for use of a particular bit pattern, called a synchronization pattern, which is inserted into the network through an empty slot. This pattern implicity defines a variable

S. Casale; A. Lombardo; S. Palazzo

1989-01-01

9

Access delay analysis of a distributed queue based ATM distributor-concentrator network  

Microsoft Academic Search

A distributed queue based ATM distributor-concentrator network may be used to provide a distributed cell multiplexing-demultiplexing function at a broadband user network interface (UNI). The distributor-concentrator network incorporates an asymmetric dual bus architecture and is based on the extended distributed queueing protocol. We analyse the access delay performance of extended distributed queueing in multiplexing the cell streams from delay-sensitive services.

Stephen G. Fischer; Guven Mercankosk

1995-01-01

10

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

Microsoft Academic Search

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

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

2010-01-01

11

Simulation Studies of Waiting Time Approximation for the Multi Priority Dual Queue (MPDQ) with Finite Waiting Room and Non-Preemptive Scheduling  

Microsoft Academic Search

In this paper we extend our work on dual queues with multi -class non-pre-emptive prioritised customers with finite waiting room to inves tigate waiting times. We consider different rates of arrival for the single and dual queueing systems, and examine the way waiting times are effected. Distribution fits are given for high class customers, and the waiting time for high

ANTHONY BEDFORD; PANLOP ZEEPHONGSEKUL

12

Reservation arbitrated access for statistical multiplexing voice traffic over dual-bus metropolitan area networks  

Microsoft Academic Search

Metropolitan area networks (MANs) are well suited to serve as broadband multiplexers for asynchronous transfer mode (ATM) networks, to facilitate enterprise networking and to support future wireless personal communication systems. We propose and analyze a novel reservation arbitrated (RA) access method which provides isochronous voice transport over dual-bus MANs while enabling statistical multiplexing among voice calls. In combination with a

Henry C. B. Chan; Victor C. M. Leung

1999-01-01

13

Queue Applet  

NSDL National Science Digital Library

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.

Gilley, Shad

14

Queueing Networks  

Microsoft Academic Search

The purpose of this tutorial is to survey queueing networks, a class of stochastic models extensively applied to represent\\u000a and analyze resource sharing systems such as communication and computer systems. Queueing networks (QNs) have been proved\\u000a to be a powerful and versatile tool for system performance evaluation and prediction. First we briefly survey QNs that consist\\u000a of a single service

Simonetta Balsamo; Andrea Marin

2007-01-01

15

Does the Butcher-on-the-Bus Phenomenon Require a Dual-Process Explanation? A Signal Detection Analysis  

PubMed Central

The butcher-on-the-bus is a rhetorical device or hypothetical phenomenon that is often used to illustrate how recognition decisions can be based on different memory processes (Mandler, 1980). The phenomenon describes a scenario in which a person is recognized but the recognition is accompanied by a sense of familiarity or knowing characterized by an absence of contextual details such as the person’s identity. We report two recognition memory experiments that use signal detection analyses to determine whether this phenomenon is evidence for a recollection plus familiarity model of recognition or is better explained by a univariate signal detection model. We conclude that there is an interaction between confidence estimates and remember-know judgments which is not explained fully by either single-process signal detection or traditional dual-process models.

Tunney, Richard J.; Mullett, Timothy L.; Moross, Claudia J.; Gardner, Anna

2012-01-01

16

Novel dual-band controller for regulating DC-bus voltage that contains a large voltage ripple  

Microsoft Academic Search

Autonomous system with DC-AC converter as an interface from the battery source to the inverter load easily suffers from voltage ripples on the DC-bus at the twice load frequency (100 Hz). A fast voltage controller for tightly regulating the DC-bus voltage with the inevitable 100 Hz ripples bears a rapid transient response, however always contaminating battery current with large ripples

Y. Wang; S. W. H. de Haan; A. van Zwam

2007-01-01

17

Tandem Brownian Queues.  

National Technical Information Service (NTIS)

We analyze a two-node tandem queue with Brownian input. We first derive an explicit expression for the joint distribution function of the workloads of the first and second queue, which also allows us to calculate their exact large-buffer asymptotics. The ...

M. R. H. Mandjes P. M. D. Lieshout

2006-01-01

18

SNOOPy Calendar Queue  

Microsoft Academic Search

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)

Kah Leong Tan; Li-Jin Thng

2000-01-01

19

Dynamic Calendar Queue  

Microsoft Academic Search

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

Jongsuk Ahn; Oh Seunghyun

1999-01-01

20

Queues with Negative Arrivals.  

National Technical Information Service (NTIS)

The authors single server queueing models where in addition to regular arriving customers, there are negative arrivals. A negative arrival has the effect of removing a customer from the queue. The way in which this removal is specified gives rise to sever...

E. Gelenbe K. Sigman P. Glynn

1989-01-01

21

Hybrid WDM Ring-Bus Optical Network  

Microsoft Academic Search

This hybrid optical network allows dual operation of ring and bus topologies, and by incorporating WDM (wavelength division multiplexing) multiple protocols can be transmitted simultaneously to achieve terabits\\/sec data rates over a single fiber.

S. W. Braun

2008-01-01

22

Demonstration of an add-drop network node with time slot access for high-speed WDMA dual bus\\/ring packet networks  

Microsoft Academic Search

High-speed wavelength division multi-access (WDMA) ring and bus networks are very promising architectures to support multi-access of high-capacity data. Most WDMA networks are configured with fixed transmitter and tunable receiver (FTTR) and employ decentralized light sources. However, they require complicated control signaling and suffer from a wavelength matching problem. In this paper, we propose and demonstrate a practical WDMA ring\\/bus

C. K. Chan; F. Tong; L. K. Chen; K. W. Cheung

1998-01-01

23

A duality model of TCP and queue management algorithms  

Microsoft Academic Search

We propose a duality model of end-to-end congestion control and apply it to understand the equilibrium properties of TCP and active queue management schemes. The basic idea is to regard source rates as primal variables and congestion measures as dual variables, and congestion control as a distributed primal-dual algorithm over the Internet to maximize aggregate utility subject to capacity constraints.

Steven H. Low

2003-01-01

24

Jitter-Conscious Bus Arbitration Scheme for Real-Time Systems  

NASA Astrophysics Data System (ADS)

Jitter is the variation of latencies, when real-time Intellectual Properties (IPs) are accessing data from the data storages. It is a critical factor for such IPs from the Quality-of-Service (QoS) perspective. Jitter of a real-time IP can be measured by how frequently it experiences the underflows and overflows from its data queue in read mode and write mode, respectively. Such failures critically depend on the bus arbitration scheme which determines the bus acquisition order of IPs. The proposed idea allows IPs to inform the bus arbiter of the status of their data buffers when they assert bus requests. Such information helps the bus arbiter to determine the bus acquisition order while greatly reducing the jitter. The experimental results show that our method effectively eliminates the overflows and underflows of real-time IPs by dynamically preempting the jitter-critical bus requests.

Roh, Jong-Ho; Jun, Minje; Bang, Kwanhu; Chung, Eui-Young

25

Queueing Networks with Finite Capacities  

Microsoft Academic Search

In this paper, we give a tutorial of queueing networks with blocking. Except for a few special cases, these networks could not be shown to have product form solutions. Although the steady state queue length distributions of these networks can, in theory, be calculated by solving the global balance equations together with the normalization equation numerically, this procedure can, in

Raif O. Onvural

1993-01-01

26

Queueing Networks in Heavy Traffic.  

National Technical Information Service (NTIS)

The principle purpose of this report is to state and prove a limit theorem which justifies a diffusion approximation for general queueing networks. The K-dimensional vector queue length process is investigated for the network. Because of the general form ...

M. I. Reiman

1977-01-01

27

Decomposing the queue length distribution of processor-sharing models into queue lengths of permanent customer queues  

Microsoft Academic Search

We obtain a decomposition result for the steady state queue length distribution in egalitarian processor-sharing (PS) models. In particular, for multi-class egalitarian PS queues, we show that the marginal queue length distribution for each class equals the queue length distribution of an equivalent single class PS model with a random number of permanent customers. Similarly, the mean sojourn time (conditioned

Sing-Kong Cheung; Hans van den Berg; Richard J. Boucherie

28

Stability, queue length, and delay of deterministic and stochastic queueing networks  

Microsoft Academic Search

We present two types of stability problems: 1) conditions for queueing networks that render bounded queue lengths and bounded delay for customers, and 2) conditions for queueing networks in which the queue length distribution of a queue has an exponential tail with rate ?. To answer these two types of stability problems, we introduce two new notions of traffic characterization:

Cheng-Shang Chang

1994-01-01

29

FLASH fiber optic data bus lessons learned  

NASA Astrophysics Data System (ADS)

The Fly-by-Light Advanced Systems Hardware (FLASH) program developed Fly-by-Light technologies for flight control and vehicle management of military and commercial aircraft. The FLASH program established requirements, performed a trade study, and selected the Dual Rate AS1773 fiber-optic data bus as the baseline interconnection means between equipment designed, built, and demonstrated by FLASH team-mates. This paper cites the lessons learned in using the AS1773 data bus. This includes the individual problems that users experienced and the overall problems of working with immature data bus components.

Green, Samuel I.

1996-10-01

30

Dynamics of Priority-Queue Networks  

NASA Astrophysics Data System (ADS)

In this Work-in-Progress paper, we study the dynamics of priority-queue networks by generalizing the interacting priority queue model of Oliveira and Vazquez [Physica A 388, 187 (2009)]. We show that the original AND-type protocol for interacting tasks is not scalable for the queue networks with more than two queues. We then introduce a scalable interaction protocol, an OR-type one, and examine the effects of the number of queues and the network topology on the waiting time dynamics of the priority-queue networks. We also study the effect of synchronicity in task executions to the waiting time dynamics in the priority-queue networks.

Min, Byung-Joon; Goh, Kwang-Il; Kim, In-Mook

31

A review on queueing network models with finite capacity queues for software architectures performance prediction  

Microsoft Academic Search

A review is carried out on how queueing network models with blocking have so far been applied into the performance evaluation and prediction of software architectures (SAs). Queueing network models with finite capacity queues and blocking have recently been introduced and applied as more realistic models of systems with finite capacity resources and population constraints. Queueing network models have been

Simonetta Balsamo; Vittoria De Nitto Persone

2003-01-01

32

Transit Bus Maintenance,  

National Technical Information Service (NTIS)

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 develop...

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

1987-01-01

33

Controlled Diffusion Approximations for Controlled Queueing Systems.  

National Technical Information Service (NTIS)

Four problem areas were studied. These are: (1) controlled heavy traffic queueing systems, (2) queueing systems with due dates, (3) backward- forward stochastic differential equations, and (4) Ginzburg-Landau equations and evolving interfaces. In areas (1...

S. E. Shreve H. M. Soner

1998-01-01

34

Sorting Using Networks of Queues and Stacks  

Microsoft Academic Search

AI~STRAC'r. The problem of sorting a sequence of numbers using a network of queues and stacks is presented. A characterization of sequences sortable using parallel queues is given, and partial characterizations of sequences sortable using parallel stacks and networks of queues are given.

Robert Endre Tarjan

1972-01-01

35

Markov-Modulated Queueing Systems  

Microsoft Academic Search

Markov-modulated queueing systems are those in which the primary arrival and service mechanisms are influenced by changes of phase in a secondary Markov process. This influence may be external or internal, and may represent factors such as changes in environment or service interruptions. An important example of such a model arises in packet switching, where the calls generating packets are

N. U. Prabhu; Yixin Zhu

1989-01-01

36

Preface: Queueing Networks with Blocking  

Microsoft Academic Search

Queueing Network Models (QNMs) with Finite Capacity provide powerful and realistic tools for the performance evaluation and prediction of discrete flow systems such as computer systems, communication networks and flexible manufacturing systems. Over recent years, there has been a great deal of progress towards the analysis and application of QNMs with finite capacity, and high quality research work has appeared

Demetres Kouvatsos; Yves Dallery

1998-01-01

37

On the Assignment of Customers to Parallel Queues  

Microsoft Academic Search

This paper considers routing to parallel queues in which each queue has its own single server, and service times are exponential with nonidentical parameters. We give conditions on the cost function such that the optimal policy assigns customers to a faster queue when that server has a shorter queue. The queues may have nite buers, and the arrival process can

Arie Hordijk; Ger Koole

1992-01-01

38

Modeling the performance of low latency queueing for emergency telecommunications  

Microsoft Academic Search

Event simulation and analytic modeling are used to evaluate the performance of low latency queueing (LLQ), a queueing discipline available in some Internet packet switching routers for integrated services performance assurance. LLQ combines priority queueing with class-based weighted fair queueing (CBWFQ). Priority queueing is used to ensure satisfying tight delay constraints for real-time traffic, whereas CBWFQ is used to ensure

Denise M. Bevilacqua Masi; Martin J. Fischer; David A. Garbin

2007-01-01

39

Message passing with queues and channels  

DOEpatents

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.

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

2013-09-24

40

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

Microsoft Academic Search

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

Randy Brown

1988-01-01

41

Bus Programmable Slave Module.  

National Technical Information Service (NTIS)

A bus programmable slave module card for use in a computer control system is disclosed which comprises a master computer and one or more slave computer modules interfacing by means of a bus. Each slave module includes its own microprocessor, memory, and c...

W. A. Hall

1989-01-01

42

Integrated sensor bus  

NASA Astrophysics Data System (ADS)

In this thesis an integrated sensor bus interface is presented. The proposed bus offers a number of interface procedures to enhance the system flexibility. It enables a 13-bit data exchange per message frame, automatic addressing, device clearing and resetting, and handling of service-request and polling procedures. Chapter 1 provides an overview of the existing data transmission technologies. It presents the most popular digital buses along with their application fields. Also other research activities on sensor buses are described. Chapter 2 deals with the requirements which have to be imposed on the desired sensor bus. It shows both communication and compatibility requirements. Chapter 3 introduces the proposed sensor bus. It presents the interface structure together with implemented bus procedures. The detailed description of the proposed sensor bus protocol is given in Chapter 4. It is divided into two parts; a logical layer description (i.e., sensor bus protocol) and a physical layer description (i.e., transmission medium and electrical characteristics). Chapter 5 deals with the compatibility issue. It investigates differences between typical processes used for sensors and digital circuits. Chapter 6 shows the design of a sensor bus interface prototype. In Chapter 7 the performance of the fabricated interface is discussed.

Rutka, M. J.

1994-03-01

43

Regeneration and Renovation in Queues  

Microsoft Academic Search

Regenerative events for different queueing models are considered. The aim of this paper is to construct these events for continuous-time\\u000a processes if they are given for the corresponding discrete-time model. The construction uses so-called renovative events revealing\\u000a the property of the state at timen of the discrete-time model to be independent (in an algebraic sense) of the states referring to

Serguei Foss; Vladimir V. Kalashnikov

1991-01-01

44

FLASH fiber optic data bus lessons learned  

Microsoft Academic Search

The Fly-by-Light Advanced Systems Hardware (FLASH) program developed Fly-by-Light technologies for flight control and vehicle management of military and commercial aircraft. The FLASH program established requirements, performed a trade study, and selected the Dual Rate AS1773 fiber-optic data bus as the baseline interconnection means between equipment designed, built, and demonstrated by FLASH team-mates. This paper cites the lessons learned in

Samuel I. Green

1996-01-01

45

Bus driver sues.  

PubMed

A bus driver, known as John Doe, sued his employer, alleging that he was fired when he voluntarily disclosed that he was HIV-positive and needed a rest from the long hours of driving. The driver sued for back wages, benefits, and compensatory and punitive damages under the New Jersey Law Against Discrimination. Academy Bus tours told the driver he could not return to work without a doctor's examination. Doe has an excellent driving record and was certified as physically fit to work as a bus driver 14 months prior to his termination. PMID:11363770

1996-09-01

46

Heuristic analysis of closed queueing networks  

Microsoft Academic Search

In this paper we consider closed queueing networks having M single server queueing stations with arbitrary interconnections and general service time distributions. Here we propose an iterative approximation procedure, based on a decomposition approximation. Numerical results are reported to demonstrate the accuracy of the method. We also discuss the sensitivity of the results to the initial guess for the server

J. G. SHANTHIKUMAR; MEHMET GOCMEN

1983-01-01

47

A Queueing Model for Business Students  

Microsoft Academic Search

In this paper we develop an N-server queueing model which overcomes some of the objections usually raised by business students when they are confronted with the discussion of queues in standard management science texts. The model permits a solution in terms of expected profit maximization rather than in terms of expected cost minimization. That is, the optimum number of servers

John S. De Cani

1962-01-01

48

The Research Queueing Package Modeling Environment (resqme)  

Microsoft Academic Search

The Research Queueing Package Modeling Environment (RESQME) provides a graphical environment for constructing, solving, and analyzing the results of extended queueing network models of resource contention systems. It has been used to improve the performance of existing and planned systems in such application areas as computer systems, communications networks, manufacturing processes, transportation systems, customer service facilities. RESQME provides the capability

Kow C. Chang; Robert F. Gordon; Paul G. Loewner; Edward A. MacNair

1993-01-01

49

Prediction in Markovian bulk arrival queues  

Microsoft Academic Search

This paper deals with the statistical analysis of bulk arrival queues from a Bayesian point of view. The focus is on prediction of the usual measures of performance of the system in equilibrium. Posterior predictive distribution of the number of customers in the system is obtained through its probability generating function. Posterior distribution of the waiting time, in the queue

Carmen Armero; David Conesa

2000-01-01

50

Effective Bandwidths at Multi-Class Queues  

Microsoft Academic Search

Consider a queue which serves traffic from a number of distinct sources and which is required to deliver a performance guarantee, expressed in terms of the mean delay or the probability the delay exceeds a thresh- old. For various simple models we show that an effective bandwidth can be associated with each source, and that the queue can deliver its

Frank P. Kelly

1991-01-01

51

The WIYN Queue: Theory Meets Reality  

NASA Astrophysics Data System (ADS)

During the past two years NOAO has conducted a queue observing experiment with the 3.5 m WIYN telescope on Kitt Peak, Arizona. The WIYN telescope is ideally suited to queue-scheduled operation in terms of its performance and its instrument complement. The queue scheduling experiment on WIYN was designed to test a number of beliefs and hypotheses about gains in efficiency and scientific effectiveness due to queue scheduling. In addition, the experiment was a test of our implementation strategy and management of community expectations. The queue is run according, to a set of rules that guide decisions about which observation to do next. In practice, scientific rank, suitability of current conditions, and the desire to complete programs all enter into these decisions. As predicted by Monte Carlo simulations, the queue increases the overall efficiency of the telescope, particularly for observations requiring, rare conditions. Together with this improvement for typical programs, the queue enables synoptic, target-of-opportunity, and short programs that could not be scheduled classically. Despite this success, a number of sociological issues determine the community's perception of the WIYN queue.

Boroson, T. A.; Harmer, D. L.; Saha, A.; Smith, P. S.; Willmarth, D. W.; Silva, D. R.

1998-07-01

52

Delay analysis of all-optical packet-switching ring and bus communications networks  

Microsoft Academic Search

We study the delay performance of all-optical packet communication networks configured as ring and bus topologies employing crossconnect switches (or wavelength routers). Under a cross-connect network implementation, a packet experiences no (or minimal) internal queueing delays. Thus, the network can be implemented by high speed all-optical components. We further assume a packet-switched network operation, such as that using a slotted

Izhak Rubin; Jing Ling

2001-01-01

53

Delay Analysis of All-Optical Packet-Switching Ring and Bus Communications Networks  

Microsoft Academic Search

We study the delay performance of all-optical packet communication networks configured as ring and bus topologies employing cross-connect switches (or wavelength routers). Under a cross-connect network implementation, a packet experiences no (or minimal) internal queueing delays. Thus, the network can be implemented by high speed all-optical components. We further assume a packet-switched network operation, such as that using a slotted

Izhak Rubin; Jing Ling

2001-01-01

54

Ring Buffered Network Bus.  

National Technical Information Service (NTIS)

This report describes the research effort to demonstrate the integration of a data sharing technology, Ring Buffered Network Bus, in development by Dryden Flight Research Center, with an engine simulation application, the Java Gas Turbine Simulator, in de...

1997-01-01

55

The M/G/1 Queue with Delayed Feedback.  

National Technical Information Service (NTIS)

The M/G/1 queue with delayed feedback is a two node queueing network. External arrivals to node one from a Poisson process. Node one has a general server with an unlimited queue capacity and a first come, first serve queue discipline. After completing ser...

R. D. Foley

1979-01-01

56

A data structure for manipulating priority queues  

Microsoft Academic Search

A data structure is described which can be used for representing a collection of priority queues. The primitive operations are insertion, deletion, union, update, and search for an item of earliest priority.

Jean Vuillemin; R. L. Rivest

1978-01-01

57

Parametric Analysis of Queueing Networks with Blocking.  

National Technical Information Service (NTIS)

Queueing networks with blocking have experienced a dramatic increase in their importance regarding performance evaluation of computer system and communication networks. Parametric Analysis is very interesting for cases in which only one station (e.g., a C...

I. F. Akyildiz

1988-01-01

58

Some Topics in Queueing Network Theory.  

National Technical Information Service (NTIS)

In the report the author summarize some of the major results obtained in the decomposition study of queueing networks. In particular, results for departure processes, decomposition switching, superposition and feedback, are reviewed. (Author)

W. P. Cherry R. L. Disney

1973-01-01

59

Rate-Controlled Static-Priority Queueing  

Microsoft Academic Search

We propose a new service discipline, called the Rate- Controlled Static-Priority(RCSP)queueingdiscipline, that can provide throughput, delay, delay jitter, and loss free guarantees in a connection-orientedpacket-switching net- work. Previously proposed solutions are based on either a time-framing strategy, or a sorted priority queue mecha- nism. Time-framing schemes suffer from the dependencies they introduce between the queueing delay and the granu- larity

Hui Zhang; Domenico Ferrari

1993-01-01

60

School Bus Facilities.  

ERIC Educational Resources Information Center

A summary is presented of a study to determine the building needs of the school transportation operation and to suggest possible uses of aluminum. The report outlines the magnitude of school transportation systems as an indication of buildings necessary to house and maintain equipment. The types of areas needed to fulfill the bus housing and…

Stanford Univ., CA. School Planning Lab.

61

Bus annunciator system  

Microsoft Academic Search

As a means of saving energy while minimizing the need for passenger cars, vans, and trucks in the Oak Ridge Y-12 Plant, buses are provided which operate along approximately 6 miles of in-plant roads. A bus annunciator system was developed, fabricated, and installed which reduces the waiting time to near zero. The system consists of three separate devices: (1) an

D. W. Carver; M. G. Duncan

1981-01-01

62

SCHOOL BUS GARAGE.  

ERIC Educational Resources Information Center

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

PALLIDINO, STEVE; STRIPLING, CHARLES W.

63

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

NASA Astrophysics Data System (ADS)

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

Ryu, S.; Wakefield, S.

2012-12-01

64

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

Microsoft Academic Search

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

Kenjiro Cho

1998-01-01

65

Queueing Models for Designing Digital Communication Satellite Systems.  

National Technical Information Service (NTIS)

Satellites have an enormous potential for providing efficient communication links between many widely scattered ground stations. By interpreting the messages as customers in a queueing system, an unusual type of queueing model can be formulated to describ...

F. S. Hillier B. Jabbari

1982-01-01

66

Algorithmic Analysis of the MMPP/G/1 Queue.  

National Technical Information Service (NTIS)

A single server queue with general service time distribution is considered when the input is a Markov modulated Poisson process (MMPP). An algorithmic solution to the transform of the stationary delay and queue length distributions is summarized, and recu...

L. Gun

1988-01-01

67

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

NASA Astrophysics Data System (ADS)

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.

Kwon, Minseok; Fahmy, Sonia

2002-07-01

68

Competitive queueing policies for QoS switches  

Microsoft Academic Search

We consider packet scheduling in a network providing differentiated services, where each packet is assigned a value. We study various queueing models for supporting QoS (Quality of Service). In the nonpreemptive model, packets accepted to the queue will be transmitted eventually and cannot be dropped. The FIFO preemptive model allows packets accepted to the queue to be preempted (dropped) prior

Nir Andelman; Yishay Mansour; An Zhu

2003-01-01

69

Dynamic queue length thresholds for multiple loss priorities  

Microsoft Academic Search

Buffer management schemes are needed in shared-memory packet switches to regulate the sharing of memory among different output port queues and among traffic classes with different loss priorities. Earlier we proposed a single-priority scheme called Dynamic Threshold (DT), in which the maximum permissible queue length is proportional to the unused buffering in the switch. A queue whose length equals or

Ellen L. Hahne; Abhijit K. Choudhury

2002-01-01

70

Strategic customer behavior in a single server queue  

Microsoft Academic Search

The purpose of this chapter is to introduce the reader to the topic of strategic behavior of customers in queues. We assume that cus- tomers individually decide on issues such as whether or not to join the queue, whether or not to renege from a queue after waiting for a while, or whether or not to pay some fee in

Moshe Haviv

71

Tables of Queue Size Distribution for Queueing Systems with Erlang Interarrival Times.  

National Technical Information Service (NTIS)

This report provides a relatively comprehensive set of tables describing the steady-state behavior of certain basic types of queueing systems having an Erlang distribution for the interarrival times. (Author)

D. M. Avis L. A. Edison L. D. Fossett F. S. Hillier M. I. Reiman

1980-01-01

72

Queue length and waiting time analysis of a batch arrival queue with bilevel control  

Microsoft Academic Search

Scope and Purpose—This paper concerns the analysis of a production system in which an early set-up and N-policy are employed. We model the system by Mx\\/M\\/1 queue with bilevel control and obtain the queue length and waiting time distributions. In general, with more than two control policies mixed up, obtaining the waiting time distribution is extremely complicated due to the

Ho Woo Lee; J. G. Park; B. K. Kim; Seung Hyun Yoon; Boo Yong Ahn; No Ik Park

1998-01-01

73

Waiting time dynamics of priority-queue networks  

NASA Astrophysics Data System (ADS)

We study the dynamics of priority-queue networks, generalizations of the binary interacting priority-queue model introduced by Oliveira and Vazquez [Physica A 388, 187 (2009)]. We found that the original AND-type protocol for interacting tasks is not scalable for the queue networks with loops because the dynamics becomes frozen due to the priority conflicts. We then consider a scalable interaction protocol, an OR-type one, and examine the effects of the network topology and the number of queues on the waiting time distributions of the priority-queue networks, finding that they exhibit power-law tails in all cases considered, yet with model-dependent power-law exponents. We also show that the synchronicity in task executions, giving rise to priority conflicts in the priority-queue networks, is a relevant factor in the queue dynamics that can change the power-law exponent of the waiting time distribution.

Min, Byungjoon; Goh, K.-I.; Kim, I.-M.

2009-05-01

74

The Markovian Queue with Bounded Waiting time  

Microsoft Academic Search

The single-server queueing system is studied where arrivals are rejected if their waiting plus service times would exceed a fixed amount K. Applications of this model include equipment repair facilities and buffered communication devices with constant discharge rate receiving messages from a high-speed data channel. A procedure for computing the equilibrium behavior is described for the case of random arrivals

Bezalel Gavish; Paul J. Schweitzer

1977-01-01

75

Competitive queue policies for differentiated services  

Microsoft Academic Search

We consider the setting of a network providing differentiated services. As is often the case in differentiated services, we assume that the packets are tagged as either being a high priority packet or a low priority packet. Outgoing links in the network are serviced by a single FIFO queue.Our model gives a benefit of ??1 to each high priority packet

William A. Aiello; Yishay Mansour; S. Rajagopolan; Adi Rosén

2005-01-01

76

Competitive Queue Policies for Differentiated Services  

Microsoft Academic Search

We consider the setting of a network providing dierentiated services. As is often the case in dierentiated services, we assume that the packets are tagged as either being a high priority packet or a low priority packet. Outgoing links in the network are serviced by a single FIFO queue. Our model gives a benefit of 1 to each high priority

William Aiello; Yishay Mansour; S. Rajagopolan; Adi Rosén

2000-01-01

77

On asymptotic accuracy in queueing theory  

Microsoft Academic Search

Recently results have shown that a single server queue Poisson Pareto Burst Process input has a tail which is bounded by hyperbolic functions. We show that the hyperbolic upper and lower bounds for this system can be very misleading, that this hyperbolic tail result is relevant only from a certain threshold on- wards, and the magnitude of this threshold may

Ronald G. Addie; Timothy D. Neame; Moshe Zukerman

78

Transient Asymptotics of Levy-Driven Queues.  

National Technical Information Service (NTIS)

With (Q(sub t))(sub t) denoting the stationary workload process in a queue fed by a Levy input process (X(sub t))(sub t), this paper focuses on the asymptotics of rare event probabilities of the type P(Q(sub 0)>pB,Q(sub T(sub B))>qB), for given positive n...

A. Es-Saghouani K. G. Debicki M. R. H. Mandjes

2008-01-01

79

Analysing Ek/Er/c Queues.  

National Technical Information Service (NTIS)

The authors study a system consisting of c parallel identical servers and a common queue. The service times are Erlang-r distributed and the interarrival times are Erlang-k distributed. The service discipline is first-come first-served. The waiting proces...

I. J. B. F. Adan W. A. van de Waarsenburg J. Wessels

1993-01-01

80

Dynamic importance sampling for queueing networks  

Microsoft Academic Search

Importance sampling is a technique that is commonly used to speed up Monte Carlo simulation of rare events. However, little is known regarding the design of efficient importance sampling algorithms in the context of queueing networks. The standard approach, which simulates the system using an a priori fixed change of measure suggested by large deviation analysis, has been shown to

Paul Dupuis; Ali Devin Sezer; Hui Wang

2007-01-01

81

Nursing Home Queues and Home Health Users  

Microsoft Academic Search

Home health market growth suggests the need for models explaining home health utilization. We have previously explained state-level Medicare home health visits with reference to nursing home markets. Here we introduce a model whereby state level Medicare home health use is a function of nursing home queues and other demand and supply factors. Medicare home health users per state population

James H. Swan; A. E. Benjamin

1994-01-01

82

Hydrogen Bus Technology Validation Program  

Microsoft Academic Search

Heavy duty engines are substantial contributors to NOX and PM emissions inventories in urban areas, and stringent emissions standards have been adopted as a consequence. CARB has passed very strict emissions standards for heavy duty engines beginning in 2007. Meeting these standards, especially for NOX emissions, may be difficult for conventional transit bus technologies. The purpose of the Hydrogen Bus

Andy Burke; Zach McCaffrey; Marshall Miller; Kirk Collier; Neal Mulligan

2005-01-01

83

Design of an asynchronous ring bus architecture for multi-core systems  

Microsoft Academic Search

In the multi-core systems, the data transfer between cores becomes a major challenge. An asynchronous ring bus, which is 33 bit width, adopting dual-rail single-track data protocol is proposed in this paper. Owning to asynchronous circuits design, there are different transfer times in different hop counts. For providing higher throughput, multiple cores which are able to access the bus simultaneously

Kai-ming Yang; Kin-fong Lei; Jih-ching Chiu

2010-01-01

84

Transaction Throughput in Distributed Systems: A Modeling Study Using Dynamic Queueing Networks.  

National Technical Information Service (NTIS)

Dynamic queueing network models are presented as an extension of classical performability models. Dynamic queueing networks, which combine product form queueing networks and generalized stochastic Petri nets are very suitable for the (extended) performabi...

B. R. Haverkort I. G. Niemegeers

1989-01-01

85

Bus vehicle status analysis in China  

Microsoft Academic Search

This paper analyses the current bus vehicle status in China, including vehicle age, bus company size, emissions standards, fuel type and bus vehicles' distribution of the country. The analysis results show that nearly one fifth vehicles are more than 8 years old; and generally the size of bus companies is small; and high emission vehicles account for a large proportion

Haozhi Zhang; Lihua Zhang; Rongxian Liu; Yulin Jiang

2011-01-01

86

Available Alternative Fuel School Bus Products--2004  

SciTech Connect

This 4-page Clean Cities fact sheet provides a list of the currently available (and soon to be available) model year 2004 alternative fuel school bus and school bus engine products. It includes information from Blue Bird Corporation, Collins Bus Corporation, Corbeil Bus, Ford Motor Company, General Motors Corporation, Thomas Built Buses, Inc., Clean Air Partners, Cummins Westport, and Deere & Company.

Not Available

2004-04-01

87

Merging and Splitting Priority Queues and Deques in Parallel  

Microsoft Academic Search

We investigate the parallel complexity of merging priority queues and double-ended priority queues (priority deques, for short). The implicit data structures that implement the queues studied in this paper are the heap, the twin-heap, the min-max heap, and the deap. It is known that heaps can be merged sequentially in sublinear time whereas merging min-max heaps requires linear sequential time.

Jingsen Chen

1992-01-01

88

The Average Velocity in a Queue  

ERIC Educational Resources Information Center

|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…

Frette, Vidar

2009-01-01

89

The Average Velocity in a Queue  

ERIC Educational Resources Information Center

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…

Frette, Vidar

2009-01-01

90

Segmented bus design for low-power systems  

Microsoft Academic Search

This paper proposes a bus-segmentation method that efficiently reduces the switched capacitance on the bus. The power consumed by the bus can, therefore, be substantially reduced. The basic idea of bus segmentation is to partition the bus into several bus segments separated by pass transistors. Highly communicating devices are located to adjacent bus segments, thus, most data communication can be

J.-Y. Chen; Wen-ben Jone; Jinn-shyan Wang; Hsueh-i Lu; T. F. Chen

1999-01-01

91

Generalized Processor Sharing Queues with Heterogeneous Traffic Classes.  

National Technical Information Service (NTIS)

We consider a queue fed by a mixture of light-tailed and heavy-tailed traffic. The two traffic flows are served in accordance with the Generalized Processor Sharing (GPS) discipline. GPS-based scheduling algorithms, such as Weighted Fair Queueing (WFQ), h...

M. J. G. van Uitert M. R. H. Mandjes S. C. Borst

2001-01-01

92

Analysis of networks buffer using discrete-time queueing models  

Microsoft Academic Search

The operation of digital systems are based on time slotting and it finds many applications particularly in communication networks. It is important to analyze a digital network on some digital concepts. In this paper we analyze the network buffer through discrete time queueing system in which queue is discrete in nature and it is used to analyze the performance of

Syed Asif Ali Shah; Wajiha Shah; U. A. Rind; G. D. Menghwar

2009-01-01

93

Improving multirobot, cooperative search via local target queues  

Microsoft Academic Search

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

Monica Anderson; Nikolaos Papanikolopoulos

2007-01-01

94

Fluid queues with long-tailed activity period distributions  

Microsoft Academic Search

This is a survey paper on fluid queues, with a strong emphasis on recent attempts to represent phenomena like long-range dependence. The central model of the paper is a fluid queueing system fed by N independent sources that alternate between silence and activity periods. The distribution of the activity periods of at least one source is assumed to be long-tailed,

Onno J. Boxma; Vincent Dumas

1998-01-01

95

The Multi-Branched Method of Moments for Queueing Networks  

Microsoft Academic Search

We propose a new exact solution algorithm for closed multiclass product-form queueing networks that is several orders of magnitude faster and less memory consuming than established methods for multiclass models, such as the Mean Value Analysis (MVA) algorithm. The technique gen- eralizes the recently proposed Method of Moments (MOM) which, differently from MVA, recursively computes higher- order moments of queue

Giuliano Casale

2009-01-01

96

Queue length and waiting-time distributions at priority intersections  

Microsoft Academic Search

Specialist literature on priority intersections provides formulas for calculating mean waiting-times and mean queue lengths for the traffic flow which has to give way (minor road). In the present paper, these results on mean values are extended to yield formulas for the corresponding distributions. This is achieved by developing a queueing-theory approach which is applied to a formula due to

Dirk Heidemann

1991-01-01

97

A scalable instruction queue design using dependence chains  

Microsoft Academic Search

Increasing the number of instruction queue (IQ) entries in a dynamically scheduled processor exposes more instruction-level parallelism, leading to higher performance. However, increasing a conventional IQ's physical size leads to larger latencies and slower clock speeds. We introduce a new IQ design that divides a large queue into small segments, which can be clocked at high frequencies. We use dynamic

Steven E. Raasch; Nathan L. Binkert; Steven K. Reinhardt

2002-01-01

98

Aids to School Bus Design  

NASA Astrophysics Data System (ADS)

Navistar International Transportation Corporation, Chicago, IL, used three separate NASA-developed technologies in the design and testing of their 3000 Series Bus Chassis which was developed expressly for school bus applications. For structural analysis, they used the MSC/NASTRAN program which mathematically analyzes a design and predicts how it will hold up under stress. They also used the SPATE 9000 system for non-contact measurement of stress, load transfer mechanisms, detection of hidden flaws, and monitoring structural changes during fatigue testing. SPATE 9000 was based on infrared stress measurement technology developed by Langley Research Center. They also employed the Wyle Ride Quality Meter, which was developed by Langley to aid in passenger aircraft design by providing an accurate measurement of ride vibration and sound level. These numbers translate into a subjective discomfort level index. These technologies contribute to the company's 45-48 percent share of the school bus chassis market.

1991-01-01

99

QSOLVE : AN OBJECT-ORIENTED SOFTWARE TOOL FOR TEACHING QUEUEING THEORY  

Microsoft Academic Search

Queueing systems are present in an enormous quantity of areas and situations of the real life, such as communication, computing, banking and transportation systems. Traditionally, queueing theory teaching is done by the development of formulations used for resolution of different kinds of queueing systems. Through these formulas we can have important information for the analysis of these queues and evaluate

Fernando C. Castaño Mariño; Paulo R. L. Gondim

100

Characterizing Bus Transit Passenger Wait Times.  

National Technical Information Service (NTIS)

Mathematical models are developed to predict bus passenger waiting time components. A statistically significant quantity of waiting time data, including related passenger attributes, transits system characteristics and bus frequency, were collected by dir...

M. D. Salek R. B. Machemehl

1999-01-01

101

Standard NIM Digital Bus (NIM/GPIB).  

National Technical Information Service (NTIS)

This document defines a standard digital data bus for NIM instruments as defined in Publication TID-20893 issued by the United States Atomic Energy Commission (now under the US Department of Energy). It utilizes the General Purpose Instrumentation Bus (GP...

1983-01-01

102

An object oriented software bus  

SciTech Connect

This paper describes a new approach to development of software for highly integrated software-hardware systems such as used for data acquisition and control. This approach, called the Object Oriented Software Bus (OSB), is a way to develop software according to a common specification similar to the way interface hardware has been developed since the advent of bus structures for minicomputers and microcomputers. Key concept of the OSB is extension of the common use of objects to support user interface and data analysis functions to the development of software objects that directly correspond to real- world hardware interfaces and modules.

McGirt, F. [Los Alamos National Lab., NM (United States); Wilkerson, J.F. [Washington Univ., Seattle, WA (United States). Dept. of Physics

1995-12-31

103

Methods for Shortening Waiting Time in Walking-Distance Introduced Queueing Systems  

NASA Astrophysics Data System (ADS)

We have investigated the walking-distance introduced queueing theory and verified that the mean waiting time in a parallel-type queueing system, i.e., queues for each service windows, becomes smaller than that in a fork-type queueing system, which collects people into a single queue, when sufficiently many people are waiting in queues. In a fork-type queueing system, a person at the head of the queue, which is usually set at the end of the system, starts to move when one of the service windows become vacant. Since this walking time from the head of the queue to the windows increases the waiting time, we propose to set the head of the queue at the center of the system and keep one person waiting at each service window when it is occupied by other person. The validity of the methods is examined by the theoretical analysis, simulations, and experiments.

Yanagisawa, Daichi; Suma, Yushi; Tomoeda, Akiyasu; Kimura, Ayako; Ohtsuka, Kazumichi; Nishinari, Katsuhiro

104

77 FR 48592 - Bus and Bus Facilities Discretionary Program Funds  

Federal Register 2010, 2011, 2012, 2013

...Transportation Equity Act: A Legacy for Users (SAFETEA-LU...equipment, and transit asset management systems. The FY 2012 Bus...Snead, Office of Program Management at (202) 366-1089, email...million, including 13 asset management projects. The selected...

2012-08-14

105

"Don't Miss the Bus!"  

ERIC Educational Resources Information Center

Presents observations from the director of the National Association of Pupil Transportation concerning school bus safety, seat belts, and the state of the $15-billion school transportation industry. Increasing student use of bus transportation and delivering the school bus safety message to all concerned are addressed. (GR)

Lieberth, Jane A.

1999-01-01

106

School Bus Accidents and Driver Age.  

ERIC Educational Resources Information Center

The study examines the rates and types of school bus accidents according to the age of the school bus driver. Accident rates in North Carolina for the school year 1971-72 were analyzed using three sources of data: accident reports, driver and mileage data, and questionnaires administered to a sample of school bus drivers. Data were obtained on…

McMichael, Judith

107

International comparisons of bus licensing  

Microsoft Academic Search

Based upon a doctoral research programme which surveyed bus and coach licensing systems throughout the world, this article seeks to arrive at a taxonomy of licensing. It identifies the familiar principles of quality, quantity and price control, examines them against the British licensing system introduced in 1930, and concludes that quantity control forms a more or less permeable barrier to

John Hibbs

1986-01-01

108

Pybus -- A Python Software Bus  

SciTech Connect

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

Lavrijsen, Wim T.L.P.

2004-10-14

109

TheM\\/G\\/1 queue with processor sharing and its relation to a feedback queue  

Microsoft Academic Search

The central model of this paper is anM\\/M\\/1 queue with a general probabilistic feedback mechanism. When a customer completes his ith service, he departs from the system with probability 1-p(i) and he cycles back with probabilityp(i). The mean service time of each customer is the same for each cycle. We determine the joint distribution of the successive sojourn times of

J. L. Van Den Berg; Onno J. Boxma

1991-01-01

110

Analysis of a Non-Trivial Queueing Network.  

National Technical Information Service (NTIS)

In studying complex queueing networks, one generally seeks to employ exact analytic solutions to reduce burden on computational resources. Barring the existence of an exact solution, the alternatives include approximation techniques and simulation. Approx...

K. S. Bellamy

1999-01-01

111

Resource Selection Using Execution and Queue Wait Time Predictions.  

National Technical Information Service (NTIS)

We developed techniques to predict application execution times for instance-based learning with an average error of 33% of average run time. We developed techniques to predict queue wait times that included a simulation of scheduling algorithms and execut...

W. Smith P. Wong

2001-01-01

112

Combining Queueing Theory with Information Theory for Multiaccess  

Microsoft Academic Search

We develop and analyze a multiaccess communication model over the additive Gaussian noise channel. The framework is information-theoretic; nonetheless it also incorporates some queueing-theoretic aspects of the problem

Ì. Emre Telatar; Robert G. Gallager

1995-01-01

113

Approximation Techniques in the Solution of Queueing Problems.  

National Technical Information Service (NTIS)

In the study of complex queueing systems analysis techniques aimed at providing exact solutions become ineffective. Approximation techniques provide an attractive alternative in such cases. This paper gives and overview of different types of approximation...

U. N. Bhat M. J. Fischer M. Shalaby

1976-01-01

114

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

SciTech Connect

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

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

2012-02-07

115

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

SciTech Connect

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.

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

116

Networks of infinite-server queues with nonstationary Poisson input  

Microsoft Academic Search

In this paper we focus on networks of infinite-server queues with nonhomogeneous Poisson arrival processes. We start by introducing a more general Poisson-arrival-location model (PALM) in which arrivals move independently through a general state space according to a location stochastic process after arriving according to a nonhomogeneous Poisson process. The usual open network of infinite-server queues, which is also known

William A. Massey; Ward Whitt

1993-01-01

117

Automated bus generation for multiprocessor SoC design  

Microsoft Academic Search

Abstract The performance of a system, especially a multiprocessor system, heavily depends upon the efficiency of its bus architecture. This paper presents a methodology to g enerate a custom,bus s ystem,for a multiprocessor System-on-a-Chip (SoC). Our bus synthesis tool (BusSyn) uses this methodology to g enerate five different bus systems as examples: Bi-FIFO Bus Architecture (BFBA), Global Bus Architecture Version

Kyeong Keol Ryu; Vincent John Mooney III

2004-01-01

118

Automated Bus Generation for Multiprocessor SoC Design  

Microsoft Academic Search

The performance of a system, especially a multiprocessor system, heavily depends upon the efficiency of its bus architecture. This paper presents a methodology to generate a custom bus system for a multiprocessor System-on-a-Chip (SoC). Our bus synthesis tool (BusSyn) uses this methodology to generate five different bus systems as examples: Bi-FIFO Bus Architecture (BFBA), Global Bus Architecture Version I (GBAVI),

Kyeong Keol Ryu; Vincent J. Mooney III

2003-01-01

119

Bus coupled systems for multigrid algorithms  

Microsoft Academic Search

Speedup and efficiency of some simple parallel multigrid algorithms for a class of bus coupled systems are investigated. We\\u000a consider some basic multigrid methods (V-cycle, W-cycle) with regular grid generation and without local refinements. Our bus\\u000a coupled systems consist of many independent processors each with its own local memory. A typical example for our abstract\\u000a bus concept is a ring

O. Kolp; H. Mierendorff

120

Introduction of Reserved Bus Lane Impact on Bus Running Time and On-Time Performance  

Microsoft Academic Search

This paper evaluates the impact of adding a reserved bus lane on the running times and on-time performance of two parallel bus routes, one of them a limited-stop bus service and the other a regular bus service. By means of automatic vehicle location and automatic passenger count data, statistical models were built to estimate running time and on-time performance. The

Julien Surprenant-Legault; Ahmed M. El-Geneidy

2011-01-01

121

Ethics in radiology: wait lists queue jumping.  

PubMed

Education in ethics is a requirement for all Royal College residency training programs as laid out in the General Standards of Accreditation for residency programs in Canada. The ethical challenges that face radiologists in clinical practice are often different from those that face other physicians, because the nature of the physician-patient interaction is unlike that of many other specialties. Ethics education for radiologists and radiology residents will benefit from the development of teaching materials and resources that focus on the issues that are specific to the specialty. This article is intended to serve as an educational resource for radiology training programs to facilitate teaching ethics to residents and also as a continuing medical education resource for practicing radiologists. In an environment of limited health care resources, radiologists are frequently asked to expedite imaging studies for patients and, in some respects, act as gatekeepers for specialty care. The issues of wait lists, queue jumping, and balancing the needs of individuals and society are explored from the perspective of a radiologist. PMID:22867960

Cunningham, Natalie; Reid, Lynette; MacSwain, Sarah; Clarke, James R

2012-08-04

122

ARCADY: A Computer Program to Model Capacities, Queues and Delays at Roundabouts.  

National Technical Information Service (NTIS)

A computer program to model capacities, queues and delays at roundabouts is described. It incorporates the latest roundabout entry capacity formula and time-dependent queueing equations. The basic inputs are certain geometric characteristics of the rounda...

E. M. Hollis M. C. Semmens S. L. Denniss

1980-01-01

123

Effectiveness of Bus Signal Priority (on CD-ROM).  

National Technical Information Service (NTIS)

The Effectiveness of Bus Signal Priority (BSP) study evaluates BSP's impact on traffic operations. The diskette provide how different situations, such as the level of congestion, placement of bus stops, presence of express bus service and number of transi...

2002-01-01

124

Road safety issues for bus transport management.  

PubMed

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

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

2013-06-20

125

Feasibility analysis of vehicular dynamic spectrum access via queueing theory model  

Microsoft Academic Search

In this paper, we present a feasibility analysis for performing vehicular dynamic spectrum access across vacant television spectral channels via a queueing theory approach that is primarily based on a multi-server, multi-priority, preemptive queue. Queueing theory has been extensively employed in the open literature to model wireless multiple access architectures as well as analyze network performance in both wired and

Si Chen; Alexander M. Wyglinski; Rama Vuyyuru; Onur Altintas

2010-01-01

126

Stability and convergence of moments for multiclass queueing networks via fluid limit models  

Microsoft Academic Search

The subject of this paper is open multiclass queueing networks, which are common models of communication networks, and complex manufacturing systems such as wafer fabrication facilities. We provide sufficient conditions for the existence of bounds on long-run average moments of the queue lengths at the various stations, and we bound the rate of convergence of the mean queue length to

Jim G. Dai; Sean P. Meyn

1995-01-01

127

Deploying Lightweight Queue Management for improving performance of Mobile Ad-hoc Networks (MANETs)  

Microsoft Academic Search

Network based congestion avoidance which involves managing the queues in the network devices is an integral part of any network. Most of the mobile networks today use Droptail queue management where packets are dropped on queue overflow. Droptail, however, is known to suffer from the well known global synchronisation problem which is characterised by the phenomenon of alternating periods of

Petre Kulkarni; Mohammad Nazeeruddin; Sally I. Mcclean; Gerard P. Parr; Michaela M. Black; Bryan W. Scotney; Petre Dini

2006-01-01

128

On the number of input queues to efficiently support multicast traffic in input queued switches  

Microsoft Academic Search

The paper studies the design of IQ cell-based switch architectures with a reduced number of queues at input ports to support multicast traffic delivery. The design involves the definition of a queueing policy (to select how and where to enqueue packets) and of a scheduling policy (to select when and from which queue to transfer packets, satisfying the transmission constraints

Andrea Bianco; Paolo Giaccone; Emilio Leonardi; Fabio Neri; Chiara Piglione

2003-01-01

129

Laboratory exercises using a graphical user interface to a queueing simulator  

Microsoft Academic Search

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,

Edward A. Billard; Alice E. Riedmiller

1997-01-01

130

Analysis of Multi-Class Queueing Systems with Finite Bufiers and Setup Times Using Decomposition Methods  

Microsoft Academic Search

In this paper, we consider two variants of a multi-class queueing system with a single server, flnite bufiers, and setup times. In the flrst variant, a setup occurs every time the server turns to a difierent class of customers, even if the queue of the scanned customer class is empty. In the second variant, the server skips empty queues and

Georg N. Krieg; Heinrich Kuhn

131

Nano Logic Circuits with Spin Wave Bus  

Microsoft Academic Search

We propose and analyze logic circuits utilizing spin waves as a physical mechanism for information transmission and processing. The novelty of this approach is that information transmission is accomplished without charge transfer. A bit of information is encoded into the phase of spin wave propagating in a ferromagnetic film - spin wave bus. The communication between the spin wave bus

Alexander Khitun; Kang L. Wang

2006-01-01

132

BUS RAPID TRANSIT: SYNTHESIS OF CASE STUDIES  

Microsoft Academic Search

Bus rapid transit systems have grown in popularity in recent years. Spurred by federal initiatives, the spiraling cost of rail transit, and market realities, a growing number of cities have installed or are planning bus rapid transit (BRT). There is a synthesis of current experience, drawing on ongoing research conducted in a project for the Transit Cooperative Research Program (TCRP).

Herbert S Levinson; Samuel Zimmerman; Jennifer Clinger; James Gast

2003-01-01

133

Alternative Fuel School Bus Information Resources  

SciTech Connect

This 4-page Clean Cities fact sheet provides a list of important resources for learning more about alternative fuels in school buses. It includes information regarding Alternative Fuel School Bus Manufacturers, Alternative Fuel HD Engine Manufacturers, Alternative Fuel School Bus Operators, and Key Web Resources for Alternative Fuels.

Not Available

2004-04-01

134

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

DOEpatents

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

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

1991-01-15

135

Characteristics of the Unexpected Message Queue of MPI applications  

SciTech Connect

High Performance Computing systems are used on a regular basis to run a myriad of application codes, yet a surprising dearth of information exists with respect to communications characteristics. Even less information is available on the low-level communication libraries, such as the length of MPI Unexpected Message Queues (UMQs) and the length of time such messages spend in these queues. Such information is vital to developing appropriate strategies for handling such data at the library and system level. In this paper we present data on the communication characteristics of three applications GTC, LSMS, and S3D. We present data on the size of their UMQ, the time spend searching the UMQ and the length of time such messages spend in these queues. We find that for the particular inputs used, these applications have widely varying characteristics with regard to UMQ length and show patterns for specific applications which persist over various scales.

Keller, Rainer [Universitat Stuttgart; Graham, Richard L [ORNL

2010-01-01

136

Simple queueing model applied to the city of Portland  

SciTech Connect

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.

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

1998-07-31

137

Analysis of an M/{Dn}/1 retrial queue  

NASA Astrophysics Data System (ADS)

We consider a single server retrial queueing system in which each customer (primary or retrial customer) has discrete service times taking on value Dj with probability , and . An arriving primary customer who finds the server busy tries later. Moreover, each retrial customer has its own orbit, and the retrial customers try to enter the service independently of each other. We call this retrial queue an M/{Dn}/1 retrial queue. A necessary and sufficient condition for this system stability is given. In the steady state, we derive the joint distribution of the state of the server and the number of customers in the retrial orbits. The explicit expressions of some performance measures are given. In addition, the steady-state distribution of the waiting time is discussed.

Wu, Xiaoyong; Ke, Xiaowu

2007-03-01

138

Examples of using the RESearch Queueing Package Modeling Environment (RESQME)  

Microsoft Academic Search

The RESearch Queueing Package Modeling Environment (RESQME) is a system which provides an integrated, graphics-oriented, performance evaluation workstation environment for constructing, maintaining, revising and evaluating performance models of resource contention systems. In this paper we discuss examples illustrating its use and emphasize the iterative nature of the modeling process. Scenarios of model specification, selection and use of confidence interval methods,

Robert F. Gordon; Edward A. MacNair; Peter D. Welch; Kurtiss J. Gordon; James F. Kurose

1986-01-01

139

Time-Dependent Descriptors for the Poisson Queue.  

National Technical Information Service (NTIS)

The theory of queueing systems at steady state is more advanced than that of systems at arbitrary points in time for two reasons. First, many systems are assumed to approximate steady state after a relatively short period of time. Second, steady state ana...

R. H. Barr

1973-01-01

140

Efficient fair queueing algorithms for packet-switched networks  

Microsoft Academic Search

Abslmcl-Although wcightcd fair queueing (WFQ) has been re- gnrdcd ns an ideal scheduling algorithm in terms of its combined dclny bound and proportional fairness properties, its asymp- totic time complexity increases linearly with the number of sessions scrviccd by the scheduler, thus limiting its use in high- speed networks. An algorithm that combines the delay and fairness bounds of WFQ

Dimitrios Stiliadis; Anujan Varma

1998-01-01

141

Design Considerations for Supporting TCP with Per-Flow Queueing  

Microsoft Academic Search

n this pape~ we investigate the extent to which fair queueing (and its variants), in conjunction with appropriately tailored buffer management schemes, can be used to achieve the following goals for TCP trajic: J) alleviate the inherent unfairness of TCP towards connections with long round-trip times, 2) provide isolation when connections using dl~erent TCP versions share a bottleneck link, 3)

Bernhard Suter; T. V. Lakshman; Dimitrios Stiliadis; Abhijit K. Choudhury

1998-01-01

142

Stability and bounds for single server queues in random environment  

Microsoft Academic Search

We consider a single server queue where the speed of the server is a function of a random environment. The only assumptions concerning the arrival process (arrival dates and service requirements) and the speed process are stationarity and ergodicity. A general expression is given for the stability condition. In the case where the two processes are independent, we show that

Francois Baccelli; Armand M. Makowski

1986-01-01

143

A Simula Program for Investigating a Class of Queueing Networks.  

National Technical Information Service (NTIS)

A queueing network model is described that may be applied to the analysis of real time distributed control systems. The model combines the main features of the BCMP class with others more common in real time systems. A simulation program for investigating...

M. Brizzi D. Grillo

1978-01-01

144

Setting Time Bounds for M/G/1 Queues.  

National Technical Information Service (NTIS)

The paper addresses the question of how long it takes for an M/G/1 queue, startig empty, to approach steady state. A coupling technique is used to derive bounds on the variation distance between the distribution of number in the system at time t and its s...

A. Merchant

1991-01-01

145

Stable Queue Management for Supporting TCP Flows over Wireless Networks  

Microsoft Academic Search

Congestion control for wireless networks is much more challenging than that for wired networks, due to the limited wireless spectrum and severe impairments of wireless medium which suffer from time-varying fading, shadowing, interference, etc. Although the stability of the Internet using TCP congestion control and active queue management (AQM) schemes has been extensively investigated, effective congestion control for wireless networks

Hiroaki Mukaidani; Lin Cai; Xuemin Shen

2011-01-01

146

M\\/M\\/1 Queueing systems with inventory  

Microsoft Academic Search

We derive stationary distributions of joint queue length and inventory processes in explicit product form for various M\\/M\\/1-systems with inventory under continuous re- view and different inventory management policies, and with lost sales. Demand is Poisson, service times and lead times are exponentially distributed. These distributions are used to calculate performance measures of the respective systems. In case of infinite

Maike Schwarz; Cornelia Sauer; Hans Daduna; Rafal Kulik; Ryszard Szekli

2006-01-01

147

Job queues and the union status of workers  

Microsoft Academic Search

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

John M. Abowd; Henry S. Farber

1982-01-01

148

CAN bus based traffic signal control system  

NASA Astrophysics Data System (ADS)

The article is focused on the fault-tolerant communication between the monitor computer and traffic signal machines, which based on the XATM-IV traffic signal control system designed by Air Traffic Management Institute of Northwestern Polytechnic University (NPU). As a popular field bus, CAN bus is adopted here to achieve above communication because of its high reliability and anti-interference ability. The design of hardware and software of CAN bus are introduced in the paper in details. At the last, some methods of fault-tolerant technique have been discussed and an efficient method is given out.

Liu, Yong; Shi, Zhongke; Su, Wuyuan

2003-09-01

149

Ultralight Stainless Steel Urban Bus Concept  

SciTech Connect

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.

J. Bruce Emmons; Leonard J. Blessing

2001-05-14

150

Characterizing bus transit passenger wait times. Research report  

Microsoft Academic Search

Mathematical models are developed to predict bus passenger waiting time components. A statistically significant quantity of waiting time data, including related passenger attributes, transits system characteristics and bus frequency, were collected by direct observation and video taping. The experimental data were collected in a six-month period at several bus transfer centers and bus stations in the city of Austin, Texas.

M. D. Salek; R. B. Machemehl

1999-01-01

151

Passenger wait time perceptions at bus stops: empirical results and impact on evaluating real-time bus arrival information  

Microsoft Academic Search

This study quantifies the relationship between perceived and actual waiting times experienced by passengers awaiting the arrival of a bus at a bus stop. Understanding such a relationship would be useful in quantifying the value of providing real-time information to passengers on the time until the next bus is expected to arrive at a bus stop. Data on perceived and

Rabi G. Mishalani; Mark M. McCord; John Wirtz

2006-01-01

152

Computer Simulation of an Electric Trolley Bus.  

National Technical Information Service (NTIS)

This report describes a computer model developed at the Transportation Systems Center (TSC) to simulate power/propulsion characteristics of an urban trolley bus. The work conducted in this area is sponsored by the Urban Mass Transportation Administration ...

J. J. Stickler

1979-01-01

153

Studies of Bus Operations in Delhi, India.  

National Technical Information Service (NTIS)

The operations were examined of the Delhi Transport Corporation (DTC), a monopoly supplier of bus services in Delhi. Detailed surveys undertaken on six routes were used to monitor the level of service and financial performance. Routes were characterized b...

P. R. Fouracre D. A. C. Maunder M. G. Pathak C. H. Rao

1981-01-01

154

Parallel Auction Algorithm for Bus Rescheduling  

Microsoft Academic Search

When a bus on a scheduled trip breaks down, one or more buses need to be rescheduled to serve the customers on that trip with\\u000a minimum operating and delay costs. The problem of reassigning buses in real-time to this cut trip, as well as to other scheduled trips with given starting and ending times, is referred to as the bus

Jing-Quan Li; Pitu B. Mirchandani; Denis Borenstein

155

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

PubMed

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

Fernandez, Roberto M; Mors, Marie Louise

2008-12-01

156

Stability of bandwidth request control based on dual feedback in BWA networks  

Microsoft Academic Search

In order for the base station to respond quickly and efficiently to the uplink bandwidth request in broadband wireless access (BWA) networks using time-division duplex (TDD), a dual feedback control algorithm has recently been proposed. In this algorithm the bandwidth request is adjusted in accordance with both the length of the backlogged queue and the mismatch between packet arrival and

Nguyen Quoc Tuan; Dinh-Thong Nguyen

2009-01-01

157

Effect of Finite State AMC on the Practicality of Dual Feedback Bandwidth Request Control  

Microsoft Academic Search

Dual feedback control algorithm has proved to allow the base station to respond quickly and efficiently to the uplink bandwidth request in broadband wireless access (BWA) networks. In this algorithm the bandwidth request is calculated based on both the length of the backlogged queue and the mismatch between packet arrival and service rates. However, the physical channel quality, SNR, does

Nguyen Quoc Tuan; Dinh-Thong Nguyen

2010-01-01

158

Performance Analysis of a Dual-Battery Scheme for Energy Efficiency in Wireless Mobile Terminals  

Microsoft Academic Search

In this paper, we propose and analyze the perfor- mance of a dual-battery scheme which exploits the relaxation phe- nomenon in batteries (under pulsed discharge conditions) to in- crease the number of packets served during the life time of a bat- tery in wireless mobile terminals. We first adopt a queueing the- ory based approach to model and analyze a

P. T. Dahake; A. Chockalingam

159

Risky behavior of bus commuters and bus drivers in Karachi, Pakistan  

Microsoft Academic Search

Buses account for a disproportionate number of road traffic accident fatalities in Karachi, Pakistan and other developing countries. Potentially dangerous bus driving and commuting practices that increase risk of road accidents and the effect of traffic police on bus behavior are evaluated. A total of 250 episodes each of disembarking and embarking commuters, buses stopping and moving on the road

Saema Mirza; Muneeza Mirza; Habib Chotani; Stephen Luby

1999-01-01

160

Mass Transit Training Needs. Volume III. Bus Operator Training Program, Bus Operator Instructor Training Program.  

National Technical Information Service (NTIS)

The report is the third of a five-volume series summarizing the finding, conclusions, and recommendations of a study of urban mass transit training needs. This volume is devoted to bus operators and bus operator instructors. A recommended standardized cou...

E. J. Thrasher

1974-01-01

161

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

ERIC Educational Resources Information Center

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

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

2003-01-01

162

MEASURING MOTORIST COMPREHENSION OF FLORIDA'S SCHOOL BUS STOP LAW AND SCHOOL BUS SIGNALIZATION DEVICES  

Microsoft Academic Search

Motorists' knowledge of Florida's school bus stop law (the Law) and various school bus signalizations was investigated and is summarized. The study focused on determining the level of motorists' knowledge regarding their driving responsibilities as defined in the Law and the meaning of the various signalizations used on school buses. To gather the necessary information, a simple one-page survey was

Michael Baltes

1998-01-01

163

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

NASA Astrophysics Data System (ADS)

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

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

2010-06-01

164

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

165

Capacity-constrained traffic assignment in networks with residual queues  

SciTech Connect

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

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

2000-04-01

166

Effect of queueing disciplines on response times in distributed systems  

SciTech Connect

A distributed program consists of processes, many of which can execute concurrently on different processors in a distributed system of processors. When several processes from the same or different distributed programs have been assigned to a processor in a distributed system, the processor must select the next process to run. The question investigated is: What is an appropriate method for selecting the next process to run. Standard processor queueing disciplines, such as first-come-first-serve and round-robin-fixed-quantum, are studied. The results for four classes of queueing disciplines tested on three problems are presented. These problems were run on a testbed, consisting of a compiler and simulator used to run distributed programs on user-specified architectures.

Williams, E.

1984-01-01

167

Two-dimensional round-robin schedulers for packet switches with multiple input queues  

Microsoft Academic Search

Abstmct— We present a new scheduler, the two-dimenswnal round-robin (2DRR) scheduler, that provides high throughput and fair access in a packet switch that uses multiple input queues. We consider an architecture in which each input port maintains a separate queue for each output. In an .V x .V switch, our scheduler determines which of the queues in the total of

Richard O. LaMaire; Dimitrios N. Serpanos

1994-01-01

168

The generalized D [X] \\/ D \\/1 queue: A flexible computer communications model  

Microsoft Academic Search

A generalization of theD[X]\\/D\\/1 queue is investigated, where independent and identically distributed (i.i.d) batches of customers arrive at a single-server queue periodically. The service requirement of a customer is a fixed constant equal for all the customers. In the time between two successive arrivals, the server can accommodate exactlyK?1 customers. The queue size and the waiting time distributions for the

Chatschik Bisdikian; John S. Lew; Asser N. Tantawi

1996-01-01

169

Simulation & Analysis of a Mean Response Time Upper-bound for Homogeneous Fork\\/Join Queues  

Microsoft Academic Search

In this paper, we study general K-queue first-in- first-out homogeneous fork\\/join queueing (HFJ) systems for any K ? 2. We simulate and analyze an upper -bound for the mean response time that we denote by TK. The upper-bound uses a relatively tiny-scale system to predict the performance of a huge-scale system. It is evaluated for 10-million queues on a regular

Ray Jinzhu Chen; Kevin Scott Reschke; Muchenxuan Tong

2011-01-01

170

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

Microsoft Academic Search

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

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

2007-01-01

171

Tacoma gets the early bus  

SciTech Connect

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 Pierce Transit, the 11-year-old municipal corporation that runs buses in Tacoma's Pierce County. He remembers getting a call from a representative of Washington Natural Gas (WNG) in the mid-1980s. WNG was trying to cultivate interest in natural gas vehicles. The two busses were placed in service in November 1986. After a three-year initial evaluation period, Pierce County Transit drew up a report indicating it was pleased with the results this far and optimistic about the use of natural gas as a motor fuel. The company calculated a break-even of 68 cents per gallon, meaning that when diesel was at the price or above, natural gas used in its place was a money-saver. By January of this year, diesel was at $1.10 per gallon. This paper reports that emissions were not tested because of the expense involved and the fact that future conversions would use a different technology. Shipley doubted, anyway, that the 60-40 combination would quite meet the emissions standards then in effect for 1991. But is was clear at a glance that particulate matter - the biggest pollution threat from diesel buses - had been significantly reduced. And that good start encouraged Pierce Transit management to plan for a fleet of vehicles that could burn 100 percent natural gas.

Kelly, T.

1991-10-01

172

Stochastic Fair Blue: A Queue Management Algorithm for Enforcing Fairness  

Microsoft Academic Search

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

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

2001-01-01

173

Deriving distribution of thread service time in layered queueing networks  

Microsoft Academic Search

Abstract—Replication,is a technique,used in distributed systems to improve performance, availability, and reliability. In replication schemes, often a J out of N voting pattern (also called quorum),is used in which the quorum,waits for J replies to arrive. Integrating a quorum,scheme,into the Layered Queueing Network,(LQN) performance modeling language necessitates the computation,of the quorum response time as the J, order statistic. To do

Tariq Omari; Salem Derisavi; Greg Franks

2007-01-01

174

Adaptive fuzzy sliding mode active queue management algorithms  

Microsoft Academic Search

Active queue management (AQM) is aimed at achieving the tradeoff between link utilization and queuing delay to enhance TCP\\u000a congestion control and is expected to perform well for a wider-range of network conditions. Static AQM schemes despite their\\u000a simplicity, often suffer from long response time due to conservative parameter setting to ensure stability. Adaptive parameter\\u000a settings, which might solve this

Xinping Guan; Bo Yang; Bin Zhao; Gang Feng; Cailian Chen

2007-01-01

175

Placing patients in the queue for coronary surgery  

Microsoft Academic Search

Objective:To determine the effects of age and work status on whether and where cardiovascular specialists would place hypothetical patients\\u000a in the queue for coronary surgery.\\u000a \\u000a Materials and methods:Mailed survey presenting a set of clinical scenarios either to be rated on a scale with 7 time frames for urgency of need\\u000a or to be designated as questionable\\/inappropriate for intervention. The basic

C. David Naylor; Carey M. Levinton; Ronald S. Baigrie; Bernard S. Goldman

1992-01-01

176

Improving runway queue management: Modifying SDSS to accommodate deicing  

Microsoft Academic Search

The FAA is sponsoring research in NextGen Surface-Trajectory-Based Operations (STBO). Surface tactical flow is a component of STBO. Collaborative Departure Queue Management (CDQM), a decision support tool (DST) used to support surface tactical flow, is currently being demonstrated at two airports, neither of which experience frequent snow events. The CDQM DST is hosted on a prototype Surface Decision Support System

Bruce Wilson; Patrick Hurley; Paul Diffenderfer

2011-01-01

177

The qnetworks Toolbox: A Software Package for Queueing Networks Analysis  

Microsoft Academic Search

\\u000a Queueing Networks QNs are a useful performance modelling notation. They can be used to describe many kinds of systems, and\\u000a efficient solution techniques have been developed for some classes of QN models. Despite the fact that QNs have been extensively\\u000a studied, very few software packages for QN analysis are available today. In this paper we describe the qnetworks toolbox, a

Moreno Marzolla

2010-01-01

178

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

DOEpatents

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

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

1999-01-01

179

Distributed bus arbitration for a multiprocessor system  

SciTech Connect

A system for providing bus arbitration for at least two processors having a common clock signal is described comprising: an asynchronous arbitration signal line connecting the processors into a ring; an asynchronous cycle grant signal line connecting the processors into a ring; arbitration control means located in each processor and coupled to the arbitration signal line for determining which processor will control arbitration for bus access on a following clock cycle, wherein the control means includes means for selecting an arbitration state of the control means; means for storing a bit indicating whether the processor has arbitration mastership; and logic means coupled to the asynchronous signal line, to the arbitration state selecting means, and to the bit storing means, for determining whether the processor will take arbitration mastership during the next cycle; cycle grant control means in each processor and coupled to the cycle grant signal line for determining which processor will have bus access on the following clock cycle.

Marin, J.S.

1988-03-08

180

ORION II bus demonstration. Demonstration report (Final)  

SciTech Connect

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 and rear doors are equipped with electrically powered ramps. Eight Thomas vehicles (22-foot, 11,500 lbs, wheelchair equipped, gasoline fueled) were also tested during the demonstration period. Operations (fuel and oil usage) and maintenance (scheduled and unscheduled) data were collected and charted-out in the report as well as driver, passenger, and maintenance surveys. This report provides descriptions, photographs, and comparison charts of both the diesel-fueled ORION II transit bus and the gasoline-fueled Thomas vehicles along with the demonstration test plan, evaluations, conclusions, and survey results.

Shanley, J.

1989-02-01

181

24. DETAIL INTERIOR VIEW OF GENERATOR BUS POTENTIAL FOR UNIT ...  

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

24. DETAIL INTERIOR VIEW OF GENERATOR BUS POTENTIAL FOR UNIT NO 1 IN BUS CELL GALLERY ON LEVEL +77 OF POWERHOUSE #1. - Bonneville Project, Powerhouse No.1, Spanning Bradford Slough, from Bradford Island, Bonneville, Multnomah County, OR

182

TMS Communications Hardware. Volume 2: Bus Interface Unit.  

National Technical Information Service (NTIS)

A prototype coaxial cable bus communication system used in the Trend Monitoring System to interconnect intelligent graphics terminals to a host minicomputer is described. The terminals and host are connected to the bus through a microprocessor-based RF mo...

J. S. Brown G. T. Hopkins

1979-01-01

183

Aircraft/stores data bus networks  

NASA Astrophysics Data System (ADS)

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

Flanagan, Richard A.; Simpson, Damon G.

184

Free-Space Optical Data Bus for Spacecraft  

Microsoft Academic Search

Our work applies optical backplane technology to the spacecraft data bus by implementing a free-space data bus suitable for the spacecraft environment. A free-space communications bus has a number of advantages, including ease of integration, ease of debugging, and lack of data harnesses. It is recognized that the free-space cavity design for an optical bus may not be suitable for

Matthew G. Bevan; M. Ann; Garrison Darrin; Suzanne C. Walts; Wolfger Schneider; Carl S. Mills; Richard F. Conde

185

Intercity express bus flow in Korea and its network analysis  

NASA Astrophysics Data System (ADS)

We investigated the express bus flow in Korea and its network topology. By using a gravity type model, we found that the bus flow between cities depends on the square root of the product of the population size of city A and the population size of city B. On the other hand, the total bus flow of a city depends on only its population size. These different dependences on population originate from the network property of the express bus network.

Kwon, Okyu; Jung, Woo-Sung

2012-09-01

186

Analysis of a diesel-electric hybrid urban bus system  

SciTech Connect

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.

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

187

Performance of multiple-bus interconnections for multiprocessors  

SciTech Connect

Bus structures, in general, are easily understood and therefore preferred by manufacturers for implementation. Multiple-bus systems can be viewed as an incremental expansion of single-bus architectures that can provide high bandwidth and reliability. This paper provides a brief overview of various analytical techniques suitable for performance evaluation of the multiple-bus multiprocessors. Some results and comparisons based on these techniques are provided.

Yang, Q. (Dept. of Electrical Engineering, Univ. of Rhode Island, Kingston, RI (US)); Bhuyan, L.N. (Center for Advanced Computer Studies, Univ. of Southwestern Louisiana, Lafayette, LA (US))

1990-03-01

188

The Development of Parameters and Warning Algorithms for an Intersection Bus-Pedestrian Collision Warning System  

Microsoft Academic Search

This study presents the conceptual design of an intersection bus-pedestrian collision warning system for bus drivers approaching an intersection. The basic parameters of the proposed design concept include the bus drivers’ perception-reaction time, the emergency deceleration rate of the bus, and pedestrian walking speed. A bus driving simulation was designed and conducted to analyze bus drivers’ responses to unexpected pedestrians

Chien-Yen Chang; Ting-Wei Chang

2011-01-01

189

SunLine Test Drives Hydrogen Bus: Hydrogen Fuel Cell& Infrastructure Technologies Program, Fuel Cell Bus Demonstration Projects (Fact Sheet)  

SciTech Connect

Fact sheet describes the ThunderPower hydrogen fuel cell bus that was demonstrated at SunLine Transit Agency from November 2002 to February 2003. The bus was evaluated by DOE's Advanced Vehicle Testing Activity.

Eudy, L.

2003-08-01

190

On high-speed data bus performance analysis  

Microsoft Academic Search

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

M. T. Ludvigson

1988-01-01

191

Simulation analysis of influence factors on bus maneuverability and stability  

Microsoft Academic Search

Bus dynamics is analyzed and 4 degrees of freedom dynamics model is established according to basic dynamic characteristics of bus. The corresponding computer simulation program is developed by using Matlab software. From practical view, structural parameters which are impacted by bus maneuverability and stability such as tire cornering stiffness, steering wheel rotational inertia, steering transmission ratio, aligning torque, around the

Hao Zhang; Xiansheng Li; Xuelian Zheng; Hongfei Liu

2010-01-01

192

El Segundo Employment Center Subscription Bus Service Demonstration: Executive Summary.  

National Technical Information Service (NTIS)

The El Segundo Employment Center Bus Service Demonstration, which came to be known as the BEEP (Bus Express Employee Program) demonstration, was undertaken with the goal of testing the viability of a new concept in subscription bus service for workers in ...

D. Daetz

1982-01-01

193

The bus overall virtual design oriented to Knowledge Based Engineering  

Microsoft Academic Search

The bus overall virtual design is very important in automobile design, which will influence the total design quality, usage performance and competitive ability in the market directly. Knowledge-Based Engineering (KBE) technology is one of the key technologies in bus overall virtual design. A bus overall virtual design based on KBE is studied in this paper. Firstly, a related database and

Zhang Yi; Mu Sihui

2010-01-01

194

SCSI-Bus Data Acquisition System for Nuclear Spectroscopy Experiments.  

National Technical Information Service (NTIS)

An IBM-386 personal computer controlled data acquisition system which uses the Small Computer System Interface (SCSI) bus as a system bus is described. The SCSI bus choice makes it easy to attach commercially available mass storage devices such as Video-8...

A. Johansson B. Hovander C. Bohm G. Appelquist

1992-01-01

195

Yet Another School Bus Tragedy Proves Drivers Need More Training.  

ERIC Educational Resources Information Center

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

Shannon, James W., Jr.

1983-01-01

196

Analysis of Dynamic Load Balancing Strategies Using a Combination of Stochastic Petri Nets and Queueing Networks  

Microsoft Academic Search

This paper is concerned with the analytical evaluation of two well known dynamic load balancing strategies, namely, shortest queue rout- ing (SQR) and shortest expected delay routing (SEDR). We overcome the limitations of existing analysis methodologies, using a well known hybrid performance model that combines generalized stochastic Petri nets and product form queueing networks. Our methodology is applicable to both

C. R. M. Sundaram; Y. Narahari

1993-01-01

197

Sample-Path Large Deviations for Tandem and Priority Queues with Gaussian Inputs.  

National Technical Information Service (NTIS)

This paper considers Gaussian flows multiplexed in a queueing network. A single node being a useful but often incomplete setting, we examine more advanced models. We focus on a (two-node) tandem queue, fed by a large number of Gaussian inputs. With servic...

M. J. G. Van Uitert M. R. H. Mandjes

2004-01-01

198

A Data Acquisition Algorithm Based on Time Slot and Circular Queue  

Microsoft Academic Search

Multi-sources data acquisition under unattended condition is a representative problem in data acquisition. An intelligent data acquisition algorithm based on time slot and circular queue is brought forward, which is achieved in identity recognition and auto-weight with nobody on duty. It utilizes the timer interaction principle in Visual Basic and the character of data store and access in circular queue.

Zhang Ruijun; Zuo Xiangguo; Chen Dingfang; Zhang Gang

2007-01-01

199

Disney's Virtual Queues: A Strategic Opportunity To Co-Brand Services?  

Microsoft Academic Search

Almost all service experiences require customers to wait in a queue at some point during the service encounter. Although waiting is a natural part of many services, for most customers, waiting is an annoyance. One of the most recent and innovative ways of making the wait invisible is through the application of virtual queues. Disney is a leader in this

Robert F. Cope; Rachelle F. Cope; Harold E. Davis

2008-01-01

200

Simterpolations: estimating an entire queueing function from a single sample path  

Microsoft Academic Search

We present an overview of a method for estimating an entire queueing function, ƒ(?), 0 ? ? c, from a single simulation sample path, where ? is the arrival rate to the system and c is the system capacity. For example, ƒ(?) could be the average sojourn time in a queueing network as a function of ?. Recently methods have

Martin I. Reiman; Burton Simon; J. Stanford Willie

1987-01-01

201

A Large-Scale Agent-Based Traffic Microsimulation Based On Queue Model  

Microsoft Academic Search

We use the so-called queue model introducted by Gawron as the base of the traffic dynamics in our micro-simulation. The queue model describes the links with a flow capacity that limits the number of agents that can leave the link and a space constraint which defines the limit of the number of agents that can be on a link at

Nurhan Cetin; Adrian Burri; Kai Nagel

202

A unified architecture for the design and evaluation of wireless fair queueing algorithms  

Microsoft Academic Search

Fair queueing in the wireless domain poses significant challenges due to unique issues in the wireless channel such as location- dependent and bursty channel errors. In this paper, we present a wireless fair service model that captures the scheduling requirements of wireless scheduling algorithms, and present a unified wireless fair queueing architecture in which scheduling algorithms can be designed to

Thyagarajan Nandagopal; Songwu Lu; Vaduvur Bharghavan

1999-01-01

203

Using an optimized queueing network model to support wafer fab design  

Microsoft Academic Search

We develop an Optimized Queueing Network (OQNet) capacity planning tool for supporting the design of new and reconfigured semiconductor fabrication facilities that makes use of queueing network approximations and an optimization routine. The basic problem addressed by this tool is to minimize the facility cost required to meet specified volume and cycle time targets. Features common to semiconductor environments, such

WALLACE J. HOPP; MARK L. SPEARMAN; SERGIO CHAYET; KAREN L. DONOHUE; ESMA S. GEL

2002-01-01

204

On queues with service and interarrival times depending on waiting times  

Microsoft Academic Search

We consider an extension of the standard G\\/G\\/1 queue, described by the equation W D = max{0,B A + Y W}, where P(Y = 1) = p and P(Y = 1) = 1 p. For p = 1 this model reduces to the classical Lindley equation for the waiting time in the G\\/G\\/1 queue, whereas for p = 0 it

Onno J. Boxma; Maria Vlasiou

2007-01-01

205

Waiting time distribution in a two-class two-server heterogeneous priority queue  

Microsoft Academic Search

Our aim is to analyze a Markovian two-class two-server queue with non-preemptive heterogeneous priority structures. We use matrix-geometric methods and derive the stationary distribution of queue lengths. To obtain the distribution of waiting times, we develop a dedicated algorithm by extending the approach of Ramaswami and Lucantoni.

H. Leemans

2001-01-01

206

The Serial Correlation Coefficients for Waiting Times in the Stationary GI\\/M\\/m Queue  

Microsoft Academic Search

Serial correlation coefficients are useful measures of the interdependence of successive waiting times. Potential applications include the development of linear predictors and determining simulation run lengths. This paper presents the algorithm for calculating such correlations in the multiserver exponential service queue, and relates it to known results for single server queues.

David A. Stanford; B. Pagurek; C. Murray Woodside

1987-01-01

207

Analysis and Simulation for a Mean Response Time Hybrid Solution to Homogeneous Fork\\/Join Queues  

Microsoft Academic Search

In this paper, we simulate and analyze general K-queue HFJ (Homogeneous Fork\\/Join) systems with 100 thousand parallel queues for the mean response time, which we denote by TK. Jobs arrive with mean rate ? and a general arrival distribution. Upon arrival, a job forks into K tasks. Task k, k = 1, 2, ..., K, is assigned to the kth

Ray Jinzhu Chen; Muchenxuan Tong

2010-01-01

208

A Fast Simulation for Thousands of General Homogeneous Fork\\/Join Queues  

Microsoft Academic Search

In this paper, we present a fast solution to simulate general K-queue HFJ (homogeneous fork\\/join) systems with thousands of parallel queues in minutes for the mean response time, which we denote by TK. The solution offers a general tool to simulate and compare TK for different algorithms of HFJ systems. As an application, we use it to compare simulation results

Ray Jinzhu Chen; Haiying Zhang; Hailong Hu

2010-01-01

209

Statistical Analysis of a Telephone Call Center: A Queueing-Science Perspective  

Microsoft Academic Search

A call center is a service network in which agents provide telephone-based services. Customers that seek these services are delayed in tele-queues. This paper summarizes an analysis of a unique record of call center operations. The data comprise a complete operational history of a small banking call center, call by call, over a full year. Taking the perspective of queueing

Lawrence Brown; Noah Gans; Avishai Mandelbaum; Anat Sakov; Haipeng Shen; Sergey Zeltyn; Linda Zhao; Novemer

2005-01-01

210

Analysis of Routes and Ridership of a Franchised Bus Service: Green Bus Lines (Revised).  

National Technical Information Service (NTIS)

New York City Department of Transportation (NYCDPT) subsidizes several franchise bus operators in Queens and Brooklyn. The Franchise operators, which started operating in the first half of the Twentieth Century, have made few changes to their routes in th...

C. E. McKnight J. Holguin-Veras H. Levinson R. E. Paaswell

2000-01-01

211

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...

212

Bus Control Systems: Their Application and Justification.  

National Technical Information Service (NTIS)

This report reviews present knowledge of bus control. It discusses the nature of the problems to be overcome, the types of control system which are available and the methods which can be applied with their aid to overcome the problems. It presents the res...

A. J. Finnamore R. L. Jackson

1978-01-01

213

Bus Incident Reporting, Tracking and Analysis System  

Microsoft Academic Search

Many Florida transit systems do little formal analysis of all accidents on an aggregate basis. In many transit system accidents and incidents are not being tracked or analyzed to identify common trends from types of incidents, location, driver, bus route, roadway characteristics and other variables that may reduce transit incidents in the future. The goal of the project was to

Deborah Buchacz Sapper; Amber Reep

2006-01-01

214

Transit bus operation with methanol fuel  

Microsoft Academic Search

American and European technology is being used to demonstrate the suitability of neat methanol as a fuel for transit buses. The project is sponsored by the California Energy Commission (CEC), and transit buses are being operated by the Golden Gate Bridge, Highway and Transportation District (GGTD). Project management and bus testing are performed by Acurex Corporation. Test data are being

M. D. Jackson; S. Unnasch; C. Sullivan; R. A. Renner

1985-01-01

215

Transit bus operation with methanol fuel  

Microsoft Academic Search

American and European technology is being used to demonstrate the suitability of neat methanol as a fuel for transit buses. The project is sponsored by the California Energy Commission (CEC), and transit buses are being operated by the golden Gate Bridge, Highway and Transportation District (GGTD). Project management and bus testing are performed by Acurex Corporation. Test data are being

M. D. Jackson; S. Unnasch; C. Sullivan

1985-01-01

216

Express Bus Transit Study: A Case Study.  

National Technical Information Service (NTIS)

Clay County Rural Transit (CCRT) is considering the implementation of an express bus system to serve commuters between the Wahpeton-Breckenridge and Fargo-Moorhead metro areas, a 55-mile trip. CCRT runs a similar service between Detroit Lakes, Barnesville...

D. Peterson J. Hough D. Ulmer

2006-01-01

217

Solving City Bus Scheduling Problems in Bangkok  

Microsoft Academic Search

The modeling of city bus scheduling problems is considered. The aim of this paper is to optimize the number of buses and their scheduling in the city. This leads to high-dimensional integer programming problems. The vehicle scheduling problem (VSP) can also be formulated through a graph-theoretical model, which is then transformed into an integer linear programming (ILP) model. There are

H. G. Bock; G. Reinelt; C. Surapholchai

218

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

SciTech Connect

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.

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

219

Ramp Metering by Limitation of Density and Queue Length  

NASA Astrophysics Data System (ADS)

As shown by many works and studies, the control of traffic flow remains the best and the efficient solution of the congestion problems. The ramp metering is a means to reduce congestion effects, it has shown his effectiveness to improve the flow and consequently to reduce the total time spent (TTS) by the vehicles in the network. In Kamel et al. [2008] the concept of flatness-based control was applied to regulate the flow at the mainline section of the road on the traffic flow model LWR. This work was preceded by Abouaïssa et al. [2006]. In this article we have proceeded the same way to set the flat output for a second order model METANET. Unfortunately we were unable to prove that the system is flat and therefore define density as flat output, but we manage to define the control laws in order to respect constraints on density and queue length at the on-ramp. The idea is to express the control variable (the outflow of the on-ramp) according to the output (density or queue length at the on-ramp), then inject it in the system. We use this control method in the ramp metering case. The first aim of the control is to keep the density in the segment where the on-ramp is connected below a density (called the target density YT) for which we have the lowest TTS, and the second aim is to keep the queue length at the on-ramp below a maximum value. In order to evaluate the controller's efficiency and applicability, a comparison is made with traditional ALINEA based controller. We illustrate this approach by comparing the cases `no control' and `ramp metering' for a simple network.

Kamel, Boumediene; Benasser, Amar; Jolly, Daniel

2009-03-01

220

Electric Bus Users Group Workshop Proceedings: April 2001 -- Tempe, Arizona  

SciTech Connect

In April 2001, EPRI sponsored a meeting to discuss the electric bus industry. Participants included bus and component manufacturers, electric utilities, and present and prospective electric bus users. The main objective of this meeting was to identify and address key issues surrounding the development and deployment of electric buses. An action plan was formulated to address the key issues identified. Technical presentations included in these proceedings cover the following topics: (1) ELFA Drive with Ultracaps for Buses (Siemens Canada); (2) Electric Bus Propulsion System with Zebra Battery and Integrated Fast Charge (Santa Barbara Electric Bus Works); and (3) Emergency Response to Electric and Hybrid Buses (J Knapp Communications).

None

2001-08-01

221

Stationary Waiting-Time Distributions for Single-Server Queues  

Microsoft Academic Search

In a single-server first-come-first-served queue the waiting-times of successive customers are related by the equation \\\\begin{equation*}\\\\tag{1}w_{n + 1} = \\\\lbrack w_n + U_n\\\\rbrack^+\\\\end{equation*} where \\\\begin{equation*}\\\\tag{2}U_n = S_n - T_n.\\\\end{equation*} Here $S_n$ and $T_n$ are the service-time of the $n$th customer, and the time between the arrivals of the $n$th and the $(n + 1)$th customers, respectively. In the particular case

R. M. Loynes

1962-01-01

222

Dual temperature dual desulfurization  

SciTech Connect

A fuel gas is desulfurized while hot by contact with a molten alkali salt. The salt is regenerated for further use by contact with a recirculating gas stream. The H/sub 2/S and COS picked up by the recirculating gas stream is scrubbed at low temperature in an aqueous alkaline salt scrub system such as hot potash. H/sub 2/S regenerated from the low temperature alkaline scrub system is subsequently converted to sulfur. By combining both high temperature and low temperature alkali scrubbing in a single dual temperature dual alkali (DTDA) process, the best advantages of both scrub techniques are retained whereas the serious disadvantages of molten salt scrubbing are eliminated.

Erickson, D.C.

1982-11-02

223

Selection of a fiber optic data bus for the FLASH program  

NASA Astrophysics Data System (ADS)

The Fly-by-Light Advanced Systems Hardware (FLASH) program is developing Fly-by-Light technologies for flight control and vehicle management of military and commercial aircraft. Fiber optics offers greatly improved data transfer rate, very low susceptibility to electromagnetic interference (EMI), lower on-board weight, and lower operating and maintenance costs. FLASH will result in demonstrations needed to gain confidence in using Fly-by-Light for flight control and vehicle management. This paper reviews the requirements and the trade study leading to selection of the dual-rate 1773A fiber optic data bus to interconnect fly-by-light advanced system hardware.

Green, Samuel I.

1995-05-01

224

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

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

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

225

A Queueing-Based Approach to Overload Detection  

NASA Astrophysics Data System (ADS)

The control of communication networks critically relies on procedures capable of detecting unanticipated load changes. In this paper we develop such techniques, in a setting in which each connection consumes roughly the same amount of bandwidth (with VoIP as a leading example). For the situation of exponential holding times an explicit analysis can be performed in a large-deviations regime, leading to approximations of the test statistic of interest (and, in addition, to results for the transient of the M/M/? queue, which are of independent interest). This procedure being applicable to exponential holding times only, and also being numerically rather involved, we then develop an approximate procedure for general holding times. In this procedure we record the number of trunks occupied at equidistant points in time {?},2{?},ldots, where {?} is chosen sufficiently large to safely assume that the samples are independent; this procedure is backed by results on the transient of the M/G/? queue. The validity of the testing procedures is demonstrated through an extensive set of numerical experiments.

Mandjes, Michel; ?uraniewski, Piotr

226

Applications of queueing theory to stochastic models of gene expression  

NASA Astrophysics Data System (ADS)

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

Kulkarni, Rahul

2012-02-01

227

Invasion percolation on a tree and queueing models.  

PubMed

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

Gabrielli, A; Caldarelli, G

2009-04-22

228

Invasion percolation on a tree and queueing models  

NASA Astrophysics Data System (ADS)

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

Gabrielli, A.; Caldarelli, G.

2009-04-01

229

CAN Bus on ExoMars  

NASA Astrophysics Data System (ADS)

This paper focuses on the implementation of CAN Bus for the EXOMars project, both on the technical aspects of the physical layer, the CAN protocol, and the higher layer protocol, and on the methodology aspects related to the procurement of multiple heterogeneous units, which need to provide a standard interface to the CAN Bus. We will present the ExoMars tailoring and technical choices using the current draft of the CAN ECSS-E50- xx-v2_1 ([5]), and we will present our conclusions regarding the use of CANopen and the draft standard. The Exomars project has successfully applied the previous efforts of CAN WG, and has established a clear implementation methodology that will provide very useful inputs for the finalization of the ECSS standardization process within next year.

Tortosa López, F.; Furano, G.; Winton, A.; Montagna, M.; Caramia, M.; Dean, B.; Bhana, M.

2009-05-01

230

An SAE high speed ring bus overview  

Microsoft Academic Search

An overview of the protocols and important features of the SAE high-speed ring bus (HSRB) standard is presented here, along with the functional design of a typical ring interface unit architecture. The counterrotating ring topology, with both loopback and bypass mechanisms, provides the high degree of fault tolerance desirable in many military and avionic systems. The error-detection, fault-detection, and recovery

Brian W. Kroeger; Hubert Shih

1988-01-01

231

Exposure assessment of diesel bus emissions.  

PubMed

The goal of this study was to measure ultrafine particle concentrations with diameters less than 1 mum emitted by diesel buses and to assess resulting human exposure levels. The study was conducted at the Woolloongabba Busway station in Brisbane, Australia in the winter months of 2002 during which temperature inversions frequently occurred. Most buses that utilize the station are fuelled by diesel, the exhaust of which contains a significant quantity of particle matter. Passengers waiting at the station are exposed to these particles emitted from the buses. During the course of this study, passenger census was conducted, based on video surveillance, yielding person-by-person waiting time data. Furthermore, a bus census revealed accurate information about the total number of diesel versus Compressed Natural Gas (CNG) powered buses. Background (outside of the bus station) and platform measurements of ultrafine particulate number size distributions were made to determine ambient aerosol concentrations. Particle number exposure concentration ranges from 10 and 40 to 60% of bus related exhaust fumes. This changes dramatically when considering the particle mass exposure concentration, where most passengers are exposed to about 50 to 80% of exhaust fumes. The obtained data can be very significant for comparison with similar work of this type because it is shown in previous studies that exhaust emissions causes cancer in laboratory animals. It was assumed that significant differences between platform and background distributions were due to bus emissions which, combined with passenger waiting times, yielded an estimate of passenger exposure to ultrafine particles from diesel buses. From an exposure point of view, the Busway station analyzed resembles a street canyon. Although the detected exhaust particle concentration at the outbound platform is found to be in the picogram range, exposure increases with the time passengers spend on the platform along with their breathing frequency. PMID:17159271

Yip, Maricela; Madl, Pierre; Wiegand, Aaron; Hofmann, Werner

2006-12-01

232

Alternative Fuel Transit Bus Evaluation Program Results  

Microsoft Academic Search

The objective of this program, which is supported bythe U.S. Department of Energy (DOE) through theNational Renewable Energy Laboratory (NREL), is toprovide an unbiased and comprehensive comparison oftransit buses operating on alternative fuels and dieselfuel. The information for this comparison was collectedfrom eight transit bus sites. The fuels studied are naturalgas (CNG and LNG), alcohol (methanol and ethanol),biodiesel (20 percent

Kevin Chandler; Norman Malcosky; Robert Motta; Paul Norton; Kenneth Kelly; Leon Schumacher

233

Initiating Bus Rapid Transit in Jakarta, Indonesia  

Microsoft Academic Search

On February 1, 2004, a 12.9-km (8-mi) bus rapid transit (BRT) line began revenue operation in Jakarta, Indonesia. The BRT line has incorporated most of the characteristics of BRT systems. The line was implemented in only 9 months at a cost of less than US$1 million\\/km ($1.6 million\\/mi). Two additional lines are scheduled to begin operation in 2005 and triple

John P Ernst

2005-01-01

234

Seriplex: A bus for simpler devices  

SciTech Connect

Seriplex, like the German/Swiss-developed AS-i sensor bus, is a bit level bus. Developed by Automated Process Control Inc. (APC), Jackson, Miss., the first Seriplex technology patent was awarded in 1987 to Robert Riley, APC vice president of engineering and product development. Square D bought APC in early 1995, and in April of that year the nonprofit Seriplex Technology Organization (STO) was established to support users and vendors using the technology. Specifically developed for industrial control applications, the Seriplex technology was designed primarily for sensors, actuators, and simple on-off devices. More than 50 vendors currently offer Seriplex products, comprising an installed base exceeding 500,000 I/O in more than 2,000 installations. Besides Square D, manufacturers include Turck, Pepperl+Fuchs, Banner Engineering, Schrader-Bellows, Mac Valves, Numatic Valves, Nematron, Xycom, TCP, Taylor Instruments, NAMCO, and Steeple-chase, among others. Seriplex is deterministic, with speeds in the low milliseconds. According to an STO {open_quotes}white paper{close_quotes} produced last year, a single network accommodates several thousand I/O devices and can extend more than 5,000 feet. Both analog and digital (binary) devices can be controlled and monitored on the network. Small Seriplex chips are embedded in sensor and actuator devices, providing direct connection to the bus. The Seriplex control bus is a serial, multiplexed, intelligent, distributed I/O system, providing both master/slave and peer-to-peer I/O control and logic, STO says. The network cable connects to I/O devices either directly via an embedded Seriplex application-specific integrated circuit (ASIC), or by means of I/O blocks that contain the Seriplex ASIC. 2 figs.

NONE

1996-11-01

235

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

SciTech Connect

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

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

1986-12-01

236

U-Bus System Design Based on WSN for the Blind People  

NASA Astrophysics Data System (ADS)

This paper proposed the U-bus system design based on wireless sensor network (WSN) for blind people. This system has two main parts. First part is blind people recognition. Another part is communication between a bus and bus station. Blind people recognition part is constructed simple device and system. This part decides existing or non-existing of the blind at bus station. And then if pre-process recognize blind people, the bus station will communicate the bus. We make up the announcement system about arrived bus information for the blind people using these parts. This announcement about arrived bus is very useful to blind people for taking the bus.

Quoc, Trung Pham; Kim, Minchul; Lee, Hyunkwan; Eom, Kihwan

237

Design theory and implementation for low-power segmented bus systems  

Microsoft Academic Search

The concept of bus segmentation has been proposed to minimize power consumption by reducing the switched capacitance on each bus [Chen et al. 1999]. This paper details the design theory and implementation issues of segmented bus systems. Based on a graph model and the Gomory-Hu cut-equivalent tree algorithm, a bus can be partitioned into several bus segments separated by pass

Wen-Ben Jone; Jinn-Shyan Wang; Hsueh-I Lu; I. P. Hsu; J.-Y. Chen

2003-01-01

238

On high-speed data bus performance analysis  

Microsoft Academic Search

The adequacy of using average throughput analysis in determining the relative performance of high-speed data bus networks is discussed. Using analytical means, the performance of three different linear bus implementations and the SAE ring bus are examined in terms of low-to-moderate, high, and worst-case throughput delays, and theoretical maximum throughput. It is shown that factors that have a major impact

M. T. Ludvigson

1988-01-01

239

Integrated modeling and optimization of a parallel hydraulic hybrid bus  

Microsoft Academic Search

Hydraulic hybrid powertrains are a critical technology used in buses to improve fuel economy and emission performance. New\\u000a exploration in configuring a parallel hydraulic hybrid bus (PHHB) is developed in this paper with no changes made to the conventional\\u000a base bus driveline. An integrated model and simulation of the parallel hydraulic hybrid bus is built based on AMESim, which\\u000a is

Y. Yan; G. Liu; J. Chen

2010-01-01

240

Modifications to a hydrogen\\/electric hybrid bus  

Microsoft Academic Search

A program to modify a hydrogen hybrid electric bus is described. This is an electric bus that uses a hydrogen-fueled internal combustion engine to charge on-board batteries. The primary goal of the reported work is to extend the range of the bus in a cost-effective manner. Among the modifications being made are the development of a new engine, upgrading the

Y. Baghzouz; J. Fiene; J. Van Dam; L. Shi; E. Wilkinson; R. Boehm

2000-01-01

241

TMS communications hardware. Volume 2: Bus interface unit  

Microsoft Academic Search

A prototype coaxial cable bus communication system used in the Trend Monitoring System to interconnect intelligent graphics terminals to a host minicomputer is described. The terminals and host are connected to the bus through a microprocessor-based RF modem termed a Bus Interface Unit (BIU). The BIU hardware and the Carrier Sense Multiple Access Listen-While-Talk protocol used on the network are

J. S. Brown; G. T. Hopkins

1979-01-01

242

Ultrasound waiting lists: rational queue or extended capacity?  

PubMed

The features and issues regarding clinical waiting lists in general and general ultrasound waiting lists in particular are reviewed, and operational aspects of providing a general ultrasound service are also discussed. A case study is presented describing a service improvement intervention in a UK NHS hospital's ultrasound department, from which arises requirements for a predictive planning model for an ultrasound waiting list. In the course of this, it becomes apparent that a booking system is a more appropriate way of describing the waiting list than a conventional queue. Distinctive features are identified from the literature and the case study as the basis for a predictive model, and a discrete event simulation model is presented which incorporates the distinctive features. PMID:18581826

Brasted, Christopher

2008-06-01

243

Simultaneous service approach for reducing air passenger queue time  

SciTech Connect

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.

Chung, C.A.; Sodeinde, T.

2000-02-01

244

Stochastic queueing-theory approach to human dynamics  

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

245

Stochastic queueing-theory approach to human dynamics.  

PubMed

Recently, numerous studies have shown that human dynamics cannot be described accurately by exponential laws. For instance, Barabási [Nature (London) 435, 207 (2005)] demonstrates that waiting times of tasks to be performed by a human are more suitably modeled by power laws. He presumes that these power laws are caused by a priority selection mechanism among the tasks. Priority models are well-developed in queueing theory (e.g., for telecommunication applications), and this paper demonstrates the (quasi-)immediate applicability of such a stochastic priority model to human dynamics. By calculating generating functions and by studying them in their dominant singularity, we prove that nonexponential tails result naturally. Contrary to popular belief, however, these are not necessarily triggered by the priority selection mechanism. PMID:22463184

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

2012-02-23

246

Quantum-information processing via a lossy bus  

SciTech Connect

We describe a method to perform two-qubit measurements and logic operations on pairs of qubits which each interact with a harmonic oscillator degree of freedom (the bus), but do not directly interact with one another. Our scheme uses only weak interactions between the qubit and the bus, homodyne measurements, and single-qubit operations. In contrast to earlier schemes, the technique presented here is extremely robust to photon loss in the bus mode, and can function with high fidelity even when the rate of photon loss is comparable to the strength of the qubit-bus coupling.

Barrett, S. D. [Hewlett-Packard Laboratories, Filton Road, Stoke Gifford, Bristol BS34 8QZ (United Kingdom); Centre for Quantum Computer Technology, University of Queensland, St Lucia, Queensland 4072 (Australia); Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Milburn, G. J. [Centre for Quantum Computer Technology, University of Queensland, St Lucia, Queensland 4072 (Australia)

2006-12-15

247

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

PubMed

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

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

2010-04-27

248

Status of the IEEE P896 Future Backplane Bus  

SciTech Connect

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

Gustavson, D.B.

1983-10-01

249

Limited-stop bus service at New York City Transit  

SciTech Connect

Improving the speed and reliability of high-volume urban bus service is an important transit planning objective. One means of increasing travel speed is to provide a limited-stop bus service component on heavily patronized local bus routes. This paper explores the characteristics of limited-stop bus service and the experiences of the Metropolitan Transit Authority (MTA)/New York City (NYC) Transit with this type of service. It also describes the key issues, factors, and customer response associated with this service strategy.

NONE

1998-11-01

250

Delayed Random Walks and Limit Theorems for Generalized Single Server Queues.  

National Technical Information Service (NTIS)

The dissertation studied a class of general single server queueing models by providing limit theorems for various stochastic processes arising out of the systems. The results include weak convergence theorems, functional strong laws, functional laws of th...

A. Lemoine

1972-01-01

251

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

NASA Astrophysics Data System (ADS)

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.

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

2010-07-01

252

Input Versus Output Queueing on a Space-Division Packet Switch  

Microsoft Academic Search

Two simple models of queueing on anN times Nspace-division packet switch are examined. The switch operates synchronously with fixed-length packets; during each time slot, packets may arrive on any inputs addressed to any outputs. Because packet arrivals to the switch are unscheduled, more than one packet may arrive for the same output during the same time slot, making queueing unavoidable.

M. J. Karol; M. G. Hluchyj; S. P. Morgan

1987-01-01

253

Using Run-Time Predictions to Estimate Queue Wait Times and Improve Scheduler Performance  

Microsoft Academic Search

On many computers, a request to run a job is not servicedimmediately but instead is placed in a queue and servicedonly when resources are released by preceding jobs.In this paper, we build on run-time prediction techniquesthat we developed in previous research to explore two problems.The first problem is to predict how long applicationswill wait in a queue until they receive

Warren Smith; Valerie E. Taylor; Ian T. Foster

1999-01-01

254

Dynamic, Transient and Stationary Behavior of the $M\\/GI\\/1$ Queue Via Martingales  

Microsoft Academic Search

An exponential martingale is associated with the Markov chain of the number of customers in the $M\\/GI\\/1$ queue. With the help of arguments from renewal theory, this martingale provides a unified probabilistic framework for deriving several well-known generating functions for the $M\\/GI\\/1$ queue, such as the Pollaczek-Khintchine formula, the transient generating function of the number of customers at departure epochs

Francois Baccelli; Armand M. Makowski

1989-01-01

255

Analysis of MultiMedia Traffic Queues with Finite Buffer and Overload Control - Part 1: Algorithm  

Microsoft Academic Search

A general solution methodology is provided for analysis of multi-media traffic queues. An efficient algorithm for a class of quasi-birth-death (QBD) processes, which are very versatile in formulating multi-media traffic queues, is described. Based on the Markov chain reduction principle, the algorithm exploits structural property to overcome the difficulties caused by the extraordinarily large state space of the model. It

Jingdong Ye; San-qi Li

1991-01-01

256

DISTRIBUTION OF THE VIRTUAL SOJOURN TIME IN THE M\\/G\\/1 PROCESSOR SHARING QUEUE1  

Microsoft Academic Search

Processor sharing queuing systems are well-known and very attractive models in applied probability and modern applications of queueing theory. This paper continues the investigations of the M\\/G\\/1 queue with Egalitarian Processor Sharing (EPS) discipline. We give, in the form of triple transforms, the time-dependent distribution of virtual sojourn time of a job, arriving at time t with the service demand

A. S. Yashkova; S. F. Yashkov

2003-01-01

257

Time dependent solution of a queueing problem with correlated batch arrivals and general service time distribution  

Microsoft Academic Search

This paper considers the transient behaviour of queueing problem in which (i) the arrivals occur in batches of variable size (ii) the arrival and no arrival of a batch at two consecutive transition marks are correlated (iii) the service time distribution for each, unit is general with probability density functionD(x). TheLaplace transform of various probability generating functions of queue length

K. Murari

1972-01-01

258

Dynamic routing of real-time jobs among parallel EDF queues: A performance study  

Microsoft Academic Search

This paper introduces an analytical method for approximating the performance of a firm real-time system consisting of a number of parallel infinite-capacity single-server queues. The service discipline for the individual queues is earliest-deadline-first (EDF). Real-time jobs with exponentially distributed relative deadlines arrive according to a Poisson process. Jobs either all have deadlines until the beginning of service or deadlines until

Mehdi Kargahi; Ali Movaghar

2010-01-01

259

Constructions of Optical Queues With a Limited Number of Recirculations--Part I: Greedy Constructions  

Microsoft Academic Search

In this two-part paper, we consider SDL constructions of optical queues with\\u000aa limited number of recirculations through the optical switches and the fiber\\u000adelay lines. We show that the constructions of certain types of optical queues,\\u000aincluding linear compressors, linear decompressors, and 2-to-1 FIFO\\u000amultiplexers, under a simple packet routing scheme and under the constraint of\\u000aa limited number

Jay Cheng; Cheng-Shang Chang; Sheng-Hua Yang; Tsz-Hsuan Chao; Duan-Shin Lee; Ching-Ming Lien

2010-01-01

260

Time-dependent analysis of virtual waiting time behaviour in discrete time queues  

Microsoft Academic Search

Discrete time queueing models have been shown previously to be of practical use for modelling the approximate time-dependent behaviour of queue length in systems of the form M(t)\\/G\\/c. In this paper we extend these models to include the time-dependent behaviour of virtual waiting time.Key components of this research are the derivation of exact (algorithmic) expressions for virtual waiting time behaviour.

A. D. Wall; D. J. Worthington

2007-01-01

261

M\\/D\\/C queue with priority: application to trunked mobile radio systems  

Microsoft Academic Search

This paper presents a procedure to estimate the mean waiting time in an M\\/D\\/C queue with two levels of nonpreemptive priority. The approximation gives a greatest relative error of 10% for heavy load and is greater than the simulated results. This makes it helpful to evaluate trunked radio systems. Introduction: The M\\/M\\/C queue model (1) usually applied to evaluate the

Francisco Barceló; Vicente Casares; Josep Paradells

1996-01-01

262

Corrected asymptotics for a multi-server queue in the Halfin-Whitt regime  

Microsoft Academic Search

To obtain insight in the quality of heavy-traffic approximations for queues with many servers, we consider the steady-state number of waiting customers in an M\\/D\\/s queue as s ? ?. In the Halfin-Whitt regime, it is well known that this random variable con- verges to the supremum of a Gaussian random walk. This paper develops methods that yield more accurate

Augustus J. E. M. Janssen; Johan Van Leeuwaarden; Bert Zwart

2008-01-01

263

A Hybrid Solution of Fork\\/Join Synchronization in Parallel Queues  

Microsoft Academic Search

Abstract? new analysis technique, dynamic-bubblesort analysis, is introduced for general K-queue first-in-first-out HFJ (homogenous fork\\/join queuing) systems of $K \\\\geq 2$. The dynamic-bubblesort model dynamically sorts the branches of the queues based on the number of the tasks waiting for synchronization in each branch. Jobs arrive with mean rate $\\\\lambda$ and a general arrival distribution. Upon arrival, a job forks

Ray Jinzhu Chen

2001-01-01

264

Savings and retail price reform in a queue-rationed economy  

Microsoft Academic Search

The paper addresses the effect on consumer saving behavior of queue rationing and of price reform in a Soviet-type economy in a lifecycle framework with overlapping generations. It is shown that consumers save less for retirement in a queue-rationed exchange economy with black markets than they would in a free-market system with the same endowments. The expectation of price reform

Michael Alexeev

1993-01-01

265

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

NASA Astrophysics Data System (ADS)

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.

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

2009-11-01

266

Communication between Host machine and the Host Bus Adapter over PCIE bus using Diagnostic window  

Microsoft Academic Search

In this paper a study of the PCIE interface and the Host Bus Adapter is carried and demonstrated the communication between the HBA and the Host through a Diagnostic Window Access of PCIE. The API are written in java to access the DDR3 and flash memory on the HBA The diagnostic method is a back door mechanism to access the

Naveen G; Sheetal Kulkarni; Naresh Madhusudhana; K N Raja Rao

2012-01-01

267

Bus Rapid Transit, Volume 1: Case Studies in Bus Rapid Transit  

Microsoft Academic Search

This report, which is published as a two-volume set, identifies the potential range of bus rapid transit (BRT) applications through 26 case studies and provides planning and implementation guidelines for BRT. This report will be useful to policy-makers, chief executive officers, and senior managers. This volume, Volume 1, provides information on the potential range of BRT applications, planning and implementation

Herbert Levinson; Samuel Zimmerman; Jennifer Clinger; Scott Rutherford; Rodney L. Smith; John Cracknell; Richard Soberman

2003-01-01

268

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

ERIC Educational Resources Information Center

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

American Federation of Teachers (NJ), 2007

2007-01-01

269

77 FR 6178 - FY 2012 Discretionary Funding Opportunities: Bus and Bus Facilities Programs (State of Good...  

Federal Register 2010, 2011, 2012, 2013

...announcement is available on the FTA Web site at: http://www.fta.dot.gov. A synopsis...government-wide electronic grants Web site at http://www.GRANTS.GOV. FTA will announce...applying can be found on FTA's Web site at http://www.fta.dot.gov/bus and...

2012-02-07

270

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

Microsoft Academic Search

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

Yili Liu; Robert Feyen; Omer Tsimhoni

2006-01-01

271

Waiting time approximation in multi-class queueing systems with multiple types of class-dependent interruptions  

Microsoft Academic Search

We consider a single-server queue subject to class-dependent interruptions motivated by vessel queueing at entrances of waterways.\\u000a Two classes of customers and k types of possibly simultaneous and class-dependent service interruptions are considered. We have employed service completion\\u000a time analysis and proposed approximations to obtain the expected waiting time of a customer (vessel) in the queue.

Özgecan S. Ulusçu; Tayfur Altiok

272

Development and application of an agricultural BUS for data transfer  

Microsoft Academic Search

Sound and sustainable agriculture without electronics is inconceivable today, as electronic systems are used to reduce farm inputs, protect the environment, secure farm income and produce high quality products. This paper explains the needs and the goals of a standardized agricultural binary unit system (BUS). Such a BUS is mandatory for efficient use of electronics in agriculture to guarantee unimpeded

Hermann Speckmann; Gerhard Jahns

1999-01-01

273

Comparison between high impedance and low impedance bus differential protection  

Microsoft Academic Search

High impedance bus differential relays are used on most of the busses in North America. The popularity can be explained by the good performance of this scheme in relation to CT saturation and the low cost, if used on a simple bus system. However with the introduction of numerical relays and their low CT burden as well as their ability

Juergen Holbach

2009-01-01

274

INSULATED BUS PIPE (IBP) FOR POWER UTILITY APPLICATIONS  

Microsoft Academic Search

In voluntary compliance of the Homeland Security Act of 2002, power utility substations feeding critical loads must be upgraded to include measures to secure against terrorist attacks. Outdoor, air insulated electrical substations use exposed bus bars and cables to connect from transformers and bus ties to switchgear equipment. A length of chain thrown over an air insulated sub-station fence could

R. Worth; Moni Islam; C. Smith

2006-01-01

275

CubeSat: developing a standard bus for picosatellites  

Microsoft Academic Search

The purpose of the CubeSat development is to define a standard bus that can be used by anyone needing a simple picosatellite. Defining a standard bus, developing standard hardware components using commercial off the shelf components and a standard spacecraft frame will simplify the development of picosatellites. The CubeSat development will provide a standard spacecraft frame, a spacecraft controller, radio

Ivan Galysh; Kevin Doherty; James McGuire; Hank Heidt; David Niemi; G. Dutchover

2000-01-01

276

Intelligent Fiberoptic Data Bus for Fly-by-Light Applications.  

National Technical Information Service (NTIS)

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 is described. The data bus is considered intelligent because it can automatically sense which station is in the t...

L. C. Manoharan S. Muthuvel

1987-01-01

277

'Busting' a gut - the strains of an urban bus driver  

Microsoft Academic Search

The profession of urban bus driving has been widely shown to be a challenging one in terms of psychosocial risk and health outcomes. This research project considers sources of occupational strain in a sample of British bus drivers. Adopting the influential models of the Job Demand\\/Control and Effort- Reward Imbalance, a questionnaire survey was completed by a number of drivers

John L. M. Tse; Rhona Flin; Kathryn Mearns

278

A High-Performance Distribution Substation Bus Topology  

Microsoft Academic Search

The ring bus configuration, a topology commonly used at transmission voltage levels, can provide significant enhancements in system reliability and improvements in operating procedures, while remaining an economical and cost-effective design. This paper analyzes the enhancements in reliability and improvements in operating procedures afforded by incorporating the ring bus topology at the transmission level, and then explores further enhancements in

Ralph E. Fehr

279

Shifts, duration of work and accident risk of bus drivers  

Microsoft Academic Search

This paper contains the results of a repetitive and comprehensive analysis of accidents of bus drivers, highlighting different aspects of the aetiology of bus drivers' accidents. The results presented in this paper indicate a strong effect of the type of shift on accident risk. Shifts starting in the morning appeared to have a higher risk than shifts starting in the

M. L. I. POKORNY; D. H. J. BLOM; P. VAN LEEUWEN

1987-01-01

280

Development of a Unitized School Bus. Volume I. Summary Report.  

National Technical Information Service (NTIS)

The development of new design concepts for school bus body structures and for passively restraining school bus passengers were the major objectives of the program. Passenger protection in front and rear rigid barrier impacts and in a side impact with a ri...

A. Khadilkar L. Adams L. Pauls W. Rup

1976-01-01

281

Bus fuel conversion to net 3-month payback  

Microsoft Academic Search

Eleven school buses in Syracuse, NY will use a mixture of compressed natural gas (CNG) and gasoline. The engine conversions will cost about $2000 per bus and have a three-month payback. On the basis of a demonstration bus performance, officials expect CNG to cost 45 cents less than gasoline. A monitoring system will record mileage, maintenance, and reliability data for

Warrock

1983-01-01

282

The Research and Realization for Passenger Car CAN Bus  

Microsoft Academic Search

In order to solve the problem of data interchange among many electronic devices of future automobile, moreover reduce wires and cost, and increase the total system reliability , we have developed a network control system of CAN (controller area network) bus based on CAN2.0B protocol and CAN bus controller MCP2510 aiming at our experiment sample car. We have applied it

Zhou Yongqin; Wang Xudong; Zhou Meilan

2006-01-01

283

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

SciTech Connect

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.

Chandler, K.; Eudy, L.

2008-10-01

284

Regenerative polymeric bus architecture for board-level optical interconnects.  

PubMed

A scalable multi-channel optical regenerative bus architecture based on the use of polymer waveguides is presented for the first time. The architecture offers high-speed interconnection between electrical cards allowing regenerative bus extension with multiple segments and therefore connection of an arbitrary number of cards onto the bus. In a proof-of-principle demonstration, a 4-channel 3-card polymeric bus module is designed and fabricated on standard FR4 substrates. Low insertion losses (? -15 dB) and low crosstalk values (< -30 dB) are achieved for the fabricated samples while better than ± 6 µm -1 dB alignment tolerances are obtained. 10 Gb/s data communication with a bit-error-rate (BER) lower than 10(-12) is demonstrated for the first time between card interfaces on two different bus modules using a prototype 3R regenerator. PMID:22714148

Bamiedakis, N; Hashim, A; Penty, R V; White, I H

2012-05-21

285

The Fairchild MIL-STD-1553 Serial Multiplex Bus Tester  

NASA Astrophysics Data System (ADS)

The Fairchild Serial Multiplex Bus Tester (SMBT) is a general purpose computer controlled MIL-STD-1553 stimulus/response/analyzer. SMBT has been selected to fulfill the data bus testing requirements of the Air Force Modular Automatic Test Equipment (MATE) systems. The design is three separate devices or functions: a monitor, a bus controller, and a remote terminal simulator, which may be operated in any combination. The purpose is to integrate the Monitor, Controller, and Remote Terminal functions into a single unit. SMBT may be controlled and synchronized by a master computer performing a coordinated total checkout of a unit under test. The monitor allows a collection of 1024 word 'windows' of bus traffic and simultaneously accumulate error statistics in all bus traffic. A system self check is incorporated as an additional feature of the design. In summary, the SMBT is designed to provide necessary stimulus, response and analysis capability for MIL-STD-1553 Line Replaceable Unit (LRU) testing.

Dunn, A. M.

286

Characterizing bus transit passenger wait times. Research report  

SciTech Connect

Mathematical models are developed to predict bus passenger waiting time components. A statistically significant quantity of waiting time data, including related passenger attributes, transits system characteristics and bus frequency, were collected by direct observation and video taping. The experimental data were collected in a six-month period at several bus transfer centers and bus stations in the city of Austin, Texas. Measured wait time was decomposed into two components: `wait time before scheduled departure time` and `wait time after scheduled departure time.` The effects of bus frequency and reliability, as well as other potential predictors on wait time components, were examined by performing Analysis of Variance and Regression. Traditional and conceptual waiting time models were evaluated using this data set and compared to the new developed models.

Salek, M.D.; Machemehl, R.B.

1999-06-01

287

GAMMA - NET: Computer network coupled by 100 MBPS Optical Fiber Ring Bus - system planning and Ring Bus subsystem description  

Microsoft Academic Search

Planning and design considerations are presented for a full scale high performance heterogeneous computer network coupled by a 100 MBPS optical fiber ring bus. The design goals of this system are efficient resource sharing and improved RAS. All common resources, such as processors, peripheral devices, terminals and file devices, are directly connected to the ring bus, instead of directly to

Katsuo Ikeda; Yoshihiko Ebihara; Michihiro Ishizaka; Takao Fujima; Tomoo Nakamura; Kazuhiko Nakayama

1980-01-01

288

High-speed transfer of two 4 KV motor bus sources using a digital motor bus transfer system  

Microsoft Academic Search

At many industrial facilities, distribution busses serving critical loads are supplied from two power sources. Typically, this bus arrangement is in a main-tie-main arrangement. Upon the loss of the normal power source, critical motor loads must be transferred to the alternate source without damaging the equipment, and ideally, without interrupting the process. In this application, two digital motor bus transfer

G. T. Orr; S. Cooper; C. J. Mozina

2010-01-01

289

High-speed transfer of two 4 KV motor bus sources using a digital motor bus transfer system  

Microsoft Academic Search

At many industrial facilities, distribution busses serving critical loads are supplied from two power sources. Typically, this bus arrangement is in a main-tie-main arrangement. Upon the loss of the normal power source, critical motor loads must be transferred to the alternate source without damaging the equipment, and ideally, without interrupting the process. In this application, two digital motor bus transfer

Gregory T. Orr; Scott Cooper

2008-01-01

290

Device and method for continuously polling for communication bus type termination  

US Patent & Trademark Office Database

Method and apparatus are disclosed for repeatedly monitoring the communication bus type and concurrently monitoring to determine if termination of the communication bus is necessary. The method comprises the steps of initializing several communication lines to logical high; determining based on the value of the input lines whether the communication bus is a parallel bus or SCSI bus; if the bus is SCSI bus, sending a low signal followed by a high signal across the output of one of the communication lines; sensing whether the communication line follows the biasing; if the output communication line follows the biasing, terminating the communication bus; if the output communication line does not follow the biasing, not terminating the communication bus. The apparatus comprises eight communication lines of the communication bus and a microprocessor electrically connected to the communication bus for stimulating and monitoring the eight communication lines in accordance with the above method.

Dearden; Grant W. (Henefer, UT); Newman; Jon B. (Centerville, UT); Baker; William P. (Salt Lake City, UT)

2001-03-20

291

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

SciTech Connect

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

Zalbowitz, M.

1992-06-02

292

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

PubMed

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

Pomeranz, Jennifer L

2012-06-28

293

An 80nm 4Gb\\/s\\/pin 32b 512Mb GDDR4 Graphics DRAM with Low-Power and Low-Noise Data-Bus Inversion  

Microsoft Academic Search

A 4Gb\\/s\\/pin 32b parallel 512Mb GDDR4 SDRAM is implemented in an 80nm DRAM process. It employs a data-bus inversion coding scheme with an analog majority voter insensitive to mismatch, which reduces peak-to-peak jitter by 21 ps and voltage fluctuation by 68mV. A dual duty-cycle corrector is proposed to average duty error, and tuning is added to the auto-calibration of driver

Jeong-Don Ihm; Seung-Jun Bae; Kwang-II Park; Ho-Young Song; Woo-Jin Lee; Hyun-Jin Kim; Kyung-Ho Kim; Ho-Kyung Lee; Min-Sang Park; Sam-Young Bang; Mi-Jin Lee; Gil-Shin Moon; Young-Wook Jang; Suk-Won Hwang; Young-Chul Cho; Sang-Jun Hwang; Dae-Hyun Kim; Ji-Hoon Lim; Jae-Sung Kim; Su-Jin Park; Ok-Joo Park; Se-Mi Yang; Jin-Yong Choi; Young-Wook Kim; Hyun-Kyu Lee; Sung-Hoon Kim; Seong-Jin Jang; Young-Hyun Jun; Soo-In Cho

2007-01-01

294

Priority queues with bursty arrivals of incoming tasks  

NASA Astrophysics Data System (ADS)

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.

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

2009-03-01

295

Investigation and replacement of bus partial differential zones in a ring bus application at centerpoint energy  

Microsoft Academic Search

This paper is based on the actual occurrence of the loss of service to all load at a CenterPoint Energy substation that serves three metropolitan underground 12.47 kV distribution networks. Subsequent investigation determined that the loss of service was caused by the maloperation of multiple, 69 kV bus electromechanical instantaneous overcurrent partial differential relay zones of protection for a fault

D. R. Sevcik; H. J. Do Carmo

2005-01-01

296

When the wheels on the bus go round: social interactions on the school bus  

Microsoft Academic Search

Children’s social interactions are often dependent upon the setting or context in which they occur. The current study explored\\u000a the school bus as a unique context for social interaction. One hundred and fifty-seven elementary school students (78 males\\u000a and 79 females), in grades 3, 4, and 5, completed a questionnaire concerning the rate and types of prosocial and aggressive\\u000a behaviors

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

2009-01-01

297

Automobile, Bus, and Rail Passenger Air Quality  

Microsoft Academic Search

Concentrations of pollutants emitted in the exhaust of gasoline and diesel engines and from\\u000a evaporation of fuels -- (e.g. CO, CO2, NO\\u000a \\u0009\\u0009\\u0009\\u0009\\u0009\\u0009\\u0009\\u0009x\\u000a \\u0009\\u0009\\u0009\\u0009\\u0009\\u0009\\u0009,\\u000a particulate matter, and volatile organic compounds) have been measured at elevated levels within the\\u000a enclosed spaces of automobile, bus, and train cabins in urban centers throughout the world and compared\\u000a to ambient air levels. The magnitude

Clifford P. Weisel

298

Dual stage passive vibration isolation for optical interferometer missions  

Microsoft Academic Search

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

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

2003-01-01

299

An Automated Dual-Wavelength Spectrophotometer Optimized for Phytochrome Assay  

Microsoft Academic Search

A microcomputer-controlled dual-wavelength spectrophotometer suitable for automated phytochrome assay is described. The optomechanical unit provides for sequential irradiation of the sample by the two measuring wavelengths with intervening dark intervals and for actinic irradiation to inter-convert phytochrome between its two forms. Photomultiplier current is amplified, converted to a digital value and transferred into the computer using a custom-designed IEEE-488 bus

Lee H. Pratt; John E. Wampler; Edwin S. Rich Jr

1984-01-01

300

A novel method to assess global voltage stability of a multi-bus power system  

Microsoft Academic Search

This paper presents a methodology to obtain an equivalent two bus network from a multi-bus network to assess critical loadability in terms of voltage stability. The weakest bus of the system being diagnosed, maximum loadability of the system is obtained for different operating condition. The methodology has also been applied to a six bus power system to assess global voltage

S. Dey; Ranjita Chowdhury; Priyanath Das

2009-01-01

301

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

ERIC Educational Resources Information Center

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…

Wisconsin State Dept. of Transportation, Madison.

302

Simulation and control of bus conditioner for a power distribution system of More Electric Aircraft  

Microsoft Academic Search

In a power distributed system of More Electric Aircraft with many loads on the dc or ac bus, there are harmonic and reactive currents when a large load is loaded or unloaded from the bus. The bus conditioner can compensate the harmonic and reactive currents on dc and ac bus in power system. This paper presents a sample of a

Shuanqin Xie; Jianying Gong; Weiguo Liu

2010-01-01

303

Queueing theory in manufacturing systems analysis and design: A classification of models for production and transfer lines  

Microsoft Academic Search

Queueing network modeling of manufacturing systems has been addressed by a large number of researchers. The purpose of this paper is to provide a bibliography of material concerned with modeling of production and transfer lines using queueing networks. Both production and transfer lines have a product-flow layout and are used in mass manufacturing. We denote production lines as flow lines

H. T. Papadopoulos; C. Heavey

1996-01-01

304

Might randomization in queue discipline be useful when waiting cost is a concave function of waiting time?  

Microsoft Academic Search

This paper suggests that introducing randomization in queue discipline might be welfare enhancing in certain queues for which the cost of waiting is a concave function of waiting time. Concavity can make increased variability in waiting times good not bad for aggregate customer welfare. Such concavity may occur if the costs of waiting asymptotically approach some maximum or if the

Jonathan P. Caulkins

2010-01-01

305

AN ASYMPTOTICALLY RISK-EFFICIENT SAMPLE ALLOCATION FOR ESTIMATING THE MEAN WAITING TIME IN THE 1 and 1 QUEUES  

Microsoft Academic Search

In this paper, we consider the problem of optimally allocating a sampling budget between the interarrival times and service times for the stationary queue and stationary queue with the goal of minimizing the mean squared error of one of four system performance measures. The natural estimator of the mean waiting time, obtained by substituting estimators for the arrival rate and

Shen Zheng; Andrew F. Seila; T. N. Sriram

2002-01-01

306

Advanced Optimization and Design Issues of a 32Bit Embedded Processor Based on Produced Order Queue Computation Model  

Microsoft Academic Search

Queue computing based programs are generated using a so called level order traversal that exposes all available parallelism in the programs. All instructions within the same level are data independent from each other and are safely to be executed in parallel. This property is lever- aged by the compiler generating queue programs with high amounts of grouped independent instructions. Thus,

Hiroki Hoshino; Ben A. Abderazek; Kenichi Kuroda

2008-01-01

307

Bus drivers' mental conditions and their relation to bus passengers' accidents with a focus on the psychological stress concept.  

PubMed

The purpose of this study was to clarify the psychological factors of bus drivers' instability that were related to bus passengers' accidents according to the hypothesis model based on the stress concept of Lazarus and Folkman (1984). This research was carried out in 2006. Participants of the study were 39 Japanese male bus drivers. Their average age was 40.2 (SD: 11.1). The average duration of employment was 4.5 (SD:6.1) years. A questionnaire was used that was composed of items concerning the frequency of bus passengers' accidents, performance of safe driving, job stressors, stress reaction and recognition from others. Based on the results, a model assuming that stress reaction caused by job stressors disturbed the bus driver's safe driving and was associated with passengers' accidents in the bus was verified to some degree. Especially, melancholy and tired feeling toward passengers showed a strong relation to the passengers' accidents in the bus. This suggested much room for intervention. Moreover, the recognition from others of their job was confirmed to act as a control factor of the stress reaction. PMID:19157155

Yamada, Yasuyuki; Mizuno, Motoki; Sugiura, Miyuki; Tanaka, Sumio; Mizuno, Yuki; Yanagiya, Toshio; Hirosawa, Masataka

2008-06-01

308

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

NASA Astrophysics Data System (ADS)

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

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

2008-02-01

309

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

NASA Astrophysics Data System (ADS)

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

Amador, J.; Artalejo, J. R.

2009-01-01

310

Development and Operational Validation of a Transit Bus Simulation.  

National Technical Information Service (NTIS)

A computer simulation incorporating the significant operational factors and transit bus characteristics has been developed to compute power, fuel consumption, and emissions over an arbitrarily prescribed mission profile. Factors considered include roadway...

J. E. Fairchild L. W. Stephens T. Williams G. A. Simmons

1975-01-01

311

Bus Land with Intermittent Priority (BLIMP) Concept Simulation Analysis.  

National Technical Information Service (NTIS)

The Lane Transit District, in cooperation with the National Bus Rapid Transit Institute (NBRTI) at the University of South Florida, completed a preliminary implementation study to determine the potential impacts of a new and innovative transit priority tr...

G. Carey K. Giese T. Basuer

2009-01-01

312

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

313

Development of an Annunciation System for Rural School Bus Operations.  

National Technical Information Service (NTIS)

The economic strength of rural areas in America requires dependable transportation, often over sparsely settled lands in all types of weather conditions. This dependency on safe and reliable mobility is certaintly true for rural school bus operations that...

C. J. Messer M. J. Pacelli

1998-01-01

314

234. Dennis Hill, Photographer July 1998 VIEW OF BUS STOP, ...  

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

234. Dennis Hill, Photographer July 1998 VIEW OF BUS STOP, UPPER DECK OF YERBA BUENA EAST VIADUCT, FACING WEST. - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

315

Evaluation of Management Options for Bus Maintenance. Executive Summary.  

National Technical Information Service (NTIS)

The purpose of this report is to address the need for a general, comprehensive document on the management of bus maintenance. A literature review of related publications confirms the need for a general, conceptual model. This report addresses the subject ...

B. E. Pake M. J. Demetsky L. A. Hoel

1985-01-01

316

Chattanooga SmartBus Project Final Phase II Evaluation Report.  

National Technical Information Service (NTIS)

This report presents the results of Phase II of the national evaluation of the Chattanooga Area Regional Transportation Authority's (CARTA's) SmartBus Project. The Smartbus Project is a comprehensive transit intelligent transportation systems (ITS) progra...

J. Bauer J. Rephlo R. Hass

2008-01-01

317

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

NASA Astrophysics Data System (ADS)

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

Saini, Sanju; Saini, J. S.

2012-11-01

318

DIMETHYL ETHER (DME)-FUELED SHUTTLE BUS DEMONSTRATION PROJECT  

SciTech Connect

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 dimethylether. 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. The 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 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 operation 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 have continued as it has been difficult to maintain operability of the shuttle bus due to fuel and component difficulties. As of late June 2002, it appears that 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 is being installed on the system to alleviate this problem and get the shuttle bus back in operation. In summary, the conversion is completed but there have been operational challenges in the field. They continue to work to make the shuttle bus as reliable to operate on DME-diesel blends as possible.

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

2003-04-01

319

Digital bus technology in new coal-fired plants  

SciTech Connect

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.

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

2007-10-15

320

Bus interdiction efforts by the police: United States v. Drayton  

Microsoft Academic Search

The Supreme Court recently addressed the constitutionality of police interdiction efforts when conducting bus sweeps. The\\u000a Court held that law enforcement officers are not required by the Fourth Amendment to “advise bus passengers of their right\\u000a not to cooperate and to refuse consent to searches” (U.S. v. Drayton, 2002, p. 2107). The decision may have implications for\\u000a how the judicial

THOMAS W. HUGHESt

2003-01-01

321

Bus fuel conversion to net 3-month payback  

SciTech Connect

Eleven school buses in Syracuse, NY will use a mixture of compressed natural gas (CNG) and gasoline. The engine conversions will cost about $2000 per bus and have a three-month payback. On the basis of a demonstration bus performance, officials expect CNG to cost 45 cents less than gasoline. A monitoring system will record mileage, maintenance, and reliability data for the converted and 11 control buses. (DCK)

Warrock, A.M.

1983-08-22

322

Compressed natural gas bus safety: a quantitative risk assessment.  

PubMed

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

Chamberlain, Samuel; Modarres, Mohammad

2005-04-01

323

Final Report for the H2Fuel Bus  

SciTech Connect

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

Jacobs, W.D.

1998-11-25

324

DIMETHYL ETHER (DME)FUELED SHUTTLE BUS DEMONSTRATION PROJECT  

Microsoft Academic Search

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

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

2003-01-01

325

DIMETHYL ETHER (DME)FUELED SHUTTLE BUS DEMONSTRATION PROJECT  

Microsoft Academic Search

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

Elana M. Chapman; Shirish Bhide; Andre L. Boehman; David Klinikowski

2003-01-01

326

Bus design, development and test for the Superconducting Super Collider  

Microsoft Academic Search

The power bus to be used in the Superconducting Super Collider magnets must operate in supercritical helium at 4.35 K and about 4 atm. The bus is nominally 17 m in length, must accommodate large differential thermal contractions, and must be amenable to large-quantity, cost-effective production, installation, and joining to adjacent magnets. It must be stable with respect to the

R. J. Thome; J. R. Hale; D. B. Montgomery; P. Thomas; Z. Piek; J. Pisera; A. Shajii; J. Zbasnik; H. W. Clay; J. Cox

1992-01-01

327

Electric-bus fast charging at the Santa Barbara MTD  

Microsoft Academic Search

The objectives of the fast charging project are to evaluate the practicality of charging battery strings at high rates, to configure an electric transit-bus with a battery system and battery monitoring system suitable for use in a rapid-recharge environment, to install a high-rate charger (Norvik 300-kW) at a location appropriate for opportunity charging, and to operate the bus and charging

D. Lemon; P. Griffith; Z. Coffman; G. Gleason

1999-01-01

328

Study of Headway Maintenance for Bus Routes: Causes and Effects of Bus Bunching in Extensive and Congested Service Areas.  

National Technical Information Service (NTIS)

Healthy and efficient public transit system is indispensable to reduce congestion, emissions, energy consumption, and car dependency in urban areas. The objective of this research is to 1) develop methods to evaluate and visualize bus service reliability ...

G. Laferriere M. Figliozzi W. Feng W. C. Feng

2012-01-01

329

DIMETHYL ETHER (DME)-FUELED SHUTTLE BUS DEMONSTRATION PROJECT  

SciTech Connect

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.

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

2003-04-01

330

Bus-tie synchronization and load share technique in a ring bus system with multiple power inverters  

Microsoft Academic Search

A novel synchronizing technique is applied to a ring bus configured power system, with multiple solid-state inverters, to allow the bus-tie breaker to be closed at any time. After paralleling, load sharing is magnetically controlled without electronic circuitry or software control. Compared to the traditional one-at-a-time synchronization process, this approach significantly shortens the synchronization time as well as the interconnect-signal

C. Mak; L. Bolster

2005-01-01

331

Dual Diagnosis  

Microsoft Academic Search

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

Mark S. Gold

2005-01-01

332

Receiver-Driven Queue Management for Achieving RTT-Fairness in Wi-Fi Networks  

Microsoft Academic Search

In this paper, we introduce a novel queue management technique for the buffer space at the base station of infrastructure 802.11 networks that considers mobile user's receiving characteristics. The maximum amount of the base station buffer that can be used by a given flow is updated proportionally to RTT, measured at the mobile nodes and sent to the base station

Dzmitry Kliazovich; Pedro Henrique Gomes; Fabrizio Granelli; Nelson L. S. da Fonseca

2009-01-01

333

Active Queue Management Mechanisms for Real-Time Traffic in MANETs.  

National Technical Information Service (NTIS)

This thesis develops active queue management mechanisms for real-time traffic for MANETs Providing QoS for real-time applications is still an open issue as stated in RFC 2309, The proposed packet-dropping algorithm called Selective Early Discard (SED) sel...

L. Fountanas

2001-01-01

334

Active Queue Management Controller using Smith Predictor for Time Delay Networks  

Microsoft Academic Search

This paper presents an investigation into a robust controller for active queue management (AQM) using Smith predictor (SP). A new SP random early detector (RED) controller is proposed and compared with traditional RED based controller. It is worth noting that the RED controller is augmented by a Smith predictor structure for plants with medium and high time delays. The proposed

Rafe Khalaf Alasem; M. Alamgir Hossain; Irfan-ullah Awan

2007-01-01

335

On Positive Harris Recurrence of Multiclass Queueing Networks: A Unified Approach Via Fluid Limit Models  

Microsoft Academic Search

It is now known that the usual traffic condition (the nominal load being less than 1 at each station) is not sufficient for stability for a multiclass open queueing network. Although there has been some progress in establishing the stability conditions for a multiclass network, there is no unified approach to this problem. In this paper, we prove that a

J. G. Dai

1995-01-01

336

DETECTION OF VEHICLES AND VEHICLE QUEUES FOR ROAD MONITORING USING HIGH RESOLUTION AERIAL IMAGES  

Microsoft Academic Search

This paper introduces a new approach to automatic vehicle detection in monocular high resolution aerial images. The extraction relies upon both local and global features of vehicles and vehicle queues, respectively. To model a vehicle on local level, a 3D-wireframe representation is used that describes the prominent geometric and radiometric features of cars including their shadow region. The model is

Stefan Hinz

337

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

SciTech Connect

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

Cownie, J.; Gropp. W.

1999-06-25

338

Rate-proportional servers: a design methodology for fair queueing algorithms  

Microsoft Academic Search

this paper we present a classof scheduling algorithms --- called Rate-Proportional Servers (RPS) --- with bounds onend-to-end delays, buffer requirements and internal traffic burstiness equal to those ofWeighted Fair Queueing. This class of algorithms is based on the notion of the potential

Dimitrios Stiliadis; Anujan Varma

1998-01-01

339

Queue dynamics of RED gateways under large number of TCP flows  

Microsoft Academic Search

We consider a stochastic model of a RED gateway under competing TCP-like sources sharing the capacity. As the number of competing flows becomes large, the queue behavior of RED can be described by a two-dimensional recursion. We confirm the result by simulations and discuss their implications for the network dimensioning problem

Peerapol Tinnakornsrisuphap; Armand M. Makowski

2001-01-01

340

Congestion Pricing and Capacity of Large Hub Airports: A Bottleneck Model with Stochastic Queues  

Microsoft Academic Search

This paper models and estimates congestion prices and capacity for large hub airports with stochastic queues, time-varying traffic rates, and endogenous intertemporal adjustment of traffic in response to queuing delay and fees. Relative costs of queuing and schedule delays are estimated using data from Minneapolis-St. Paul. Simulations calculate equilibrium traffic patterns, queuing delays, schedule delays, congestion fees, airport revenues, airport

Joseph I. Daniel

1995-01-01

341

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

Microsoft Academic Search

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

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

1995-01-01

342

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

343

Optimal control of admission to a station in a closed two queue system  

Microsoft Academic Search

We consider a closed queueing system consisting of two stations in tandem. The controller has to make a decision on the number of customers to be admitted for service at the first station so that a long term utility function is maximized. We study the nature of optimal policy for some classes of utility function and transition probability structures. This

Taposh Banerjee; Arzad Alam Kherani

2006-01-01

344

A Fuzzy Logic Based Network Congestion Control Using Active Queue Management Techniques  

Microsoft Academic Search

Conventional IP routers are passive devices that accept packets and perform the routing function on any input. Usually the tail-drop (TD) strategy is used where the input which exceeds the buffer capacity are simply dropped. In active queue management (AQM) methods routers manage their buffers by dropping packets selectively. We study one of the AQM methods called as random exponential

I. K. Tabash; M. A. A. Mamun; A. Negi

2010-01-01

345

Bulk service queues with deviations from departure schedules: The problem of correlated headways  

Microsoft Academic Search

The usual approach to studying bulk service queues is to assume that successive headways are independent. This assumption is frequently violated in systems where vehicles depart according to a fixed schedule, but where deviations from the schedule may occur. A late departure implies there is one long headway followed by a shorter one. This problem is solved exactly using both

Warren B. Powell

1983-01-01

346

An introduction to the RESearch Queueing Package for modeling contention systems  

Microsoft Academic Search

A queueing network is an important tool for modeling systems where performance is principally affected by contention for resources. Such systems include computer systems, communication networks and manufacturing lines. In order to effectively use queuing networks as performance models, appropriate software is necessary for definition of the networks to be solved, for solution of the networks and for examination of

E. A. MacNair; R. F. Gordon

1994-01-01

347

CONTRAM: A Traffic Assignment Model for Predicting Flows and Queues during Peak Periods.  

National Technical Information Service (NTIS)

The report describes a computer-based traffic assignment and queueing model for use in the design of urban traffic management schemes. The model is called CONTRAM - CONtinuous TRaffic Assignment Model. CONTRAM requires data on time-varying flow demands (f...

D. R. Leonard J. B. Tough P. C. Baguley

1978-01-01

348

Queueing-Model-Based Adaptive Control of Multi-Tiered Web Applications  

Microsoft Academic Search

Web applications have been increasingly deployed on the Internet. How to effectively allocate system resources to meet the Service Level Objectives (SLOs) is a challenging problem for Web application providers. In this article, we propose a scheme for automated performance control of Web applications via dynamic resource allocations. The scheme uses a queueing model predictor and an online adaptive feedback

Xue Liu; Jin Heo; Lui Sha; Xiaoyun Zhu

2008-01-01

349

Secure Wireless Communication and Optimal Power Control Under Statistical Queueing Constraints  

Microsoft Academic Search

In this paper, secure transmission of information over fading broadcast channels is studied in the presence of statistical queueing constraints. Effective capacity is employed as a perfor- mance metric to identify the secure throughput of the system, i.e., effective secure throughput. It is assumed that perfect channel side information (CSI) is available at both the transmitter and the receivers. Initially,

Deli Qiao; Mustafa Cenk Gursoy; Senem Velipasalar

2011-01-01

350

A Performance Analysis of TMN Systems Using Models of Networks of Queues, Jackson's Theorem and Simulation  

Microsoft Academic Search

We analyze the performance of a telecommunications management network (TMN) system using models of networks of queues, Jackson's theorem, and simulation. TMN systems for managing public asynchronous transfer mode (ATM) networks generally have a four-level hierarchical structure consisting of a network management system, a few element management systems (EMSs), and several pairs of agents and ATM switches. We construct a

Young Ha Hwang; Sang Wook Chung; Gil-Haeng Lee; Young Il Kim

2002-01-01

351

Waiting Time Distribution in a Class of Discrete-Time Cyclic Service Multi-Queue Systems  

Microsoft Academic Search

A new approximate method is developed for finding the waiting and sojourn time distributions in a class of multi-queue systems served in cyclic order at discrete intervals. An immediate application for such a model is in communication networks where a number of different traffic sources compete to access a group of transmission channels operating under a time-slotted sharing policy. This

Sérgio Coury; Peter G. Harrison

1997-01-01

352

Waiting time analysis of a two-stage queueing system with priorities  

Microsoft Academic Search

A two-stage queueing system with two types of customers and non-preemptive priorities is analyzed. There is no waiting space between stages and so the blocking phenomenon is observed. The arrivals follow a Poisson distribution for the high priority customers and a gamma distribution for the low priority customers, while all service times are arbitrarily distributed. We derive expressions for the

Christos Langaris

1993-01-01

353

Asymptotic Inference for Waiting Times and Patiences in Queues with Abandonment  

Microsoft Academic Search

Motivated by applications in call center management, we propose a framework based on empirical process techniques for inference about the waiting time and patience distribution in multiserver queues with abandonment. The framework rigorises heuristics based on survival analysis of independent and identically distributed observations by allowing correlated successive waiting times. Assuming a regenerative structure of the sequence of oered waiting

Anders Gorst-rasmussen; Martin B. Hansen

2009-01-01

354

The unbalance and bounds on the average waiting time for periodic routing to one queue  

Microsoft Academic Search

In this paper we introduce the combinatorial notion of unbalance for a periodic zero-one splitting sequence. Using this unbalance we derive an upper bound for the average expected waiting time of jobs which are routed to one queue according to a periodic zero-one splitting sequence. In the companion paper [16] the upper bound will be extended to the routing to

Arie Hordijk; Dinard van der Laan

2004-01-01

355

Workload and Waiting Time Analyses of MAP\\/G\\/1 Queue under D-policy  

Microsoft Academic Search

We study the workload (unfinished work) and the waiting time of the queueing system with MAP arrivals under D-policy. The D-policy stipulates that the idle server begin to serve the customers only when the sum of the service times of all waiting customers exceeds some fixed threshold D. We first set up the system equations for workload and obtain the

Ho Woo Lee; Sahng Hoon Cheon; Eui Yong Lee; Kyung C. Chae

2004-01-01

356

Approximate mean waiting time in a GI\\/D\\/1 queue with autocorrelated times to failures  

Microsoft Academic Search

In this paper, we study process completion time and propose an accurate approximation for the mean waiting time in queues with servers experiencing autocorrelated times to failure, which include only busy periods from a repair completion until the next failure. To do this, we employ a three-parameter renewal approximation that represents the stream of autocorrelated times to failure. The approximation

Bari? Balciolu; David L. Jagerman; Tayfur Altiok

2007-01-01

357

Utilization of Idle Time in an M\\/G\\/1 Queueing System  

Microsoft Academic Search

This paper studies an M\\/G\\/1 queue where the idle time of the server is utilized for additional work in a secondary system. As usual, the server is busy as long as there are units in the main system. However, as soon as the server becomes idle he leaves for a \\

Yonatan Levy; Uri Yechiali

1975-01-01

358

Performance prediction of loss and delay Markovian queueing model with nopassing and removable additional servers  

Microsoft Academic Search

In this investigation, the loss and delay Markovian queueing system with nopassing is proposed. The customers may balk or renege with certain probability, on finding all servers busy on their arrival. To cope up with the balking and reneging behaviour of the customers, there is provision of removable additional servers apart from permanent servers so as to provide the better

Madhu Jain; Poonam Singh

2003-01-01

359

The Sojourn Time in a Three Node, Acyclic, Jackson Queueing Network.  

National Technical Information Service (NTIS)

In this paper we consider the three node, acyclic, Jackson queueing network discussed by Simon and Foley (1980). We provide a solution to the sojourn time problem for a given customer. To the best of our knowledge, this is the first solution to the sojour...

P. Kiessler R. L. Disney

1982-01-01

360

G\\/M\\/1 queue study of buffer behavior in the decoding system of computer communication  

Microsoft Academic Search

This paper deals with the buffer behavior at the decoding center of a computer communication system in which the messages are in the Huffman code of English text. It is assumed that the arrival of messages has an arbitrary distribution, with the message lengths having negative exponential distribution. The situation is well described by the G\\/M\\/1 model of queue theory.

H. M. Srivastava; H. B. Kekre; Y. N. Bapat

1977-01-01

361

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

Microsoft Academic Search

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.

MARTIN REISER

1979-01-01

362

Channel capacity fair queueing in wireless networks: issues and a new algorithm  

Microsoft Academic Search

Wireless fair queueing algorithms have been extensively studied recently. However, a major drawback in existing approaches is that the channel model is overly simplified - a two states (good or bad) channel is assumed. While it is relatively easy to analyze the system using such a simple model, the algorithms so designed are of a limited applicability in a practical

Li Wang; Yu-Kwong Kwok; Wing-Cheong Lau; Vincent K. N. Lau

2002-01-01

363

Minimizing Mean Flowtime in the Flow Shop with No Intermediate Queues  

Microsoft Academic Search

This paper deals with the flow shop model in which no intermediate job queues are permitted. A branch and bound algorithm for minimizing mean flowtime is developed and detailed computational experience is reported. Experimental results suggest that this problem can be solved as readily as the makespan problem in the traditional flow shop model.

John M. Van Deman; Kenneth R. Baker

1974-01-01

364

Entry Times in Queues with Endogenous Arrivals: Dynamics of Play on the Individual and Aggregate Levels  

Microsoft Academic Search

This chapter considers arrival time and staying out decisions in several variants of a queueing game characterized by endogenously determined arrival times, simultaneous play, finite populations of symmetric players, discrete strategy spaces, and fixed starting and closing times of the service facility. Experimental results show 1) consistent patterns of behavior on the aggregate level in all the conditions that are

J. Neil Bearden; Amnon Rapoport; Darryl A. Seale

365

A systems analysis and model of a parallel multi-server queueing system  

Microsoft Academic Search

A feasible set of management policies to handle multitandem queueing systems characterized by stochastic demand is presented in this paper. This type of system is common in many service related organizations. The research employs a previously developed simulation model of a State of Florida driver licensing office to manipulate policy variables in an effort to provide options for increased system

Thomas D. Clark Jr.; Donald H. Hammond; Kathy L. McCommon

1990-01-01

366

Experiences of Fast Queue health care users in primary health care facilities in eThekwini district, South Africa.  

PubMed

Background: Comprehensive Primary Health Care (PHC), based on the principles of accessibility, availability, affordability, equity and acceptability, was introduced in South Africa to address inequalities in health service provision. Whilst the Fast Queue was instrumental in the promotion of access to health care, a major goal of the PHC approach, facilities were not prepared for the sudden influx of clients. Increased access resulted in long waiting times and queues contributing to dissatisfaction with the service which could lead to missed appointments and non-compliance with established treatment plans. Objectives: Firstly to describe the experiences of clients using the Fast Queue strategy to access routine healthcare services and secondly, to determine how the clients' experiences led to satisfaction or dissatisfaction with the Fast Queue service.Method: A descriptive qualitative survey using content analysis explored the experiences of the Fast Queue users in a PHC setting. Setting was first identified based on greatest number using the Fast Queue and geographic diversity and then a convenience sample of health care users of the Fast Queue were sampled individually along with one focus group of users who accessed the Queue monthly for medication refills. The same interview guide questions were used for both individual interviews and the one focus group discussion. Five clinics with the highest number of attendees during a three month period and a total of 83 health care users of the Fast Queue were interviewed. The average participant was female, 31 years old, single and unemployed.Results: Two themes with sub-themes emerged: health care user flow and communication, which highlights both satisfaction and dissatisfaction with the fast queue and queue marshals, could assist in directing users to the respective queues, reduce waiting time and keep users satisfied with the use of sign posts where there is a lack of human resources.Conclusion: Effective health communication strategies contribute to positive experiences by health care users and these can be effected by: (1) involvement of health care providers in planning the construction of health facilities to give input about patient flow, infection prevention and control and provision of privacy, (2) effective complaints mechanisms for users to ensure that complaints are followed up and (3)encouraging users to arrive at the facility throughout the day, rather than the present practice where all users arrive at the clinic early in the morning.  PMID:23902165

Sokhela, Dudu G; Makhanya, Nonhlanhla J; Sibiya, Nokuthula M; Nokes, Kathleen M

2013-07-05

367

Analysis of U.S. School Bus Populations and Alternative Fuel Potential  

SciTech Connect

This Clean Cities final report provides information concerning different school bus types, school bus populations, school bus miles and fuel use, school bus emissions, alternative fuel school buses, and potential for alternative fuel school bus use through 2010. It is intended to provide general information concerning the size of the school bus market in the U.S., as well as to provide some quantification of the potential for alternative fuel use in school buses in the U.S., and what that might mean for petroleum displacement and emissions reductions.

Laughlin, M.

2004-04-01

368

Overview hazard analysis for the H2Fuel Bus Program  

SciTech Connect

The H2Fuel Bus project is a joint development effort to produce a safe, near-zero emission, 32 passenger bus that is propelled by electric power with continuous on-board hydrogen powered battery recharging. A key initiative in the hydrogen bus development effort is a rigorous evaluation of operational safety. Westinghouse Savannah River Co., the prime contractor at the Department of Energy`s Savannah River Site, has developed a hazard analysis methodology designed to provide a systematic, comprehensive identification and evaluation of hazards. Although originally developed to support nuclear/chemical facility safety basis documentation, the SRS Methodology has widespread applicability to operations and/or systems that utilize hazardous materials and energy. This methodology was used to perform an overview hazard analysis for the H2Fuel Bus project to focus attention on those hypothetical circumstances that pose the greatest threat to the populace and property. The hazard analysis yields a listing of all known H2Fuel Bus hazards, postulated accident scenarios describing possible hazardous releases or conditions, an assessment of the scenarios in terms of frequency of occurrence and consequence, and binning in frequency-consequence space to assess the relative severity of postulated scenarios.

Hovis, G.L.

1996-06-18

369

Model to Evaluate the Impacts of Bus Priority on Signalized Intersections.  

National Technical Information Service (NTIS)

The concept of providing bus priority at signals is not new. Numerous cities have implemented bus priority strategies at signals with varying degree of success. Many of these cities have, however, discontinued using the priority measures. The advent of ne...

S. R. Sunkari P. S. Beasley T. Urbanik D. B. Fambro

1994-01-01

370

Optimization Models for Prioritizing Bus Stop Facility Investments for Riders with Disabilities.  

National Technical Information Service (NTIS)

The Americans with Disabilities Act (ADA) of 1990 prescribes the minimum requirements for bus stop accessibility by riders with disabilities. Due to limited budgets, transit agencies can only select a limited number of bus stop locations for ADA improveme...

A. Gan D. Shen F. Cevallos W. Wu

2010-01-01

371

Quantum bus of metal nanoring with surface plasmon polaritons  

SciTech Connect

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 nanoring. 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.

Lin Zhirong; Guo Guoping; Tu Tao; Li Haiou; Zou Changling; Ren Xifeng; Guo Guangcan [Key Laboratory of Quantum Information, Chinese Academy of Sciences, University of Science and Technology of China, Hefei 230026 (China); Chen Junxue; Lu Yonghua [Department of Physics, Anhui Key Laboratory of Optoelectronic Science and Technology, University of Science and Technology of China, Hefei 230026 (China)

2010-12-15

372

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

SciTech Connect

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

Warren, C.

1982-08-18

373

Fuzzy logic control for active bus suspension system  

NASA Astrophysics Data System (ADS)

In this study an active controller is presented for vibration suppression of a full-bus suspension model that use air spring. Since the air spring on the full-bus model may face different working conditions, auxiliary chambers have been designed. The vibrations, caused by the irregularities of the road surfaces, are tried to be suppressed via a multi input-single output fuzzy logic controller. The effect of changes in the number of auxiliary chambers on the vehicle vibrations is also investigated. The numerical results demonstrate that the presented fuzzy logic controller improves both ride comfort and road holding.

Turkkan, Mujde; Yagiz, Nurkan

2013-02-01

374

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

PubMed Central

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

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

2013-01-01

375

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

PubMed

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

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

2013-06-18

376

Use of Metallurgical Analysis to Pinpoint a Brake Problem and the Cause of a Bus Fire  

Microsoft Academic Search

The incident of concern involves a tour bus that caught fire. The fire took place while the bus was traveling at highway speeds.\\u000a Bus fires can be catastrophic, consuming the entire vehicle and threatening the lives of passengers. In this case, the fire\\u000a was detected soon enough to allow the bus to be evacuated. Further, the fire was extinguished in

Richard A. Hargis; Tim Jur

2008-01-01

377

A low-cost memory remapping scheme for address bus protection  

Microsoft Academic Search

The address sequence on the processor-memory bus can reveal abun- dant information about the control o w of a program. This can lead to critical information leakage such as encryption keys or propri- etary algorithms. Addresses can be observed by attaching a hard- ware device on the bus that passively monitors the bus transac- tion. Such side-channel attacks should be

Lan Gao; Jun Yang; Marek Chrobak; Youtao Zhang; San Nguyen; Hsien-hsin S. Lee

2006-01-01

378

OPF based voltage stability assessment of a multi-bus power system using network equivalencing technique  

Microsoft Academic Search

In this paper a unique methodology for assessment of voltage stability is proposed considering economic criteria using the concept of equivalencing the multi-bus system to a two bus radial system and by studying the necessary parameters of the equivalent system. Hence, a generalized global voltage stability indicator being developed, it has been applied to a typical 6-bus system and a

Palukuru Nagendra; S. H. nee Dey; Subrata Paul

2009-01-01

379

A simulation model of the SAE AE9B high speed ring bus (HSRB)  

Microsoft Academic Search

The SAE HSRB model capabilities are described and the results of the AE-9B bus design performance analysis used to validate model operations are discussed. The HSRB simulations revealed that the bus throughput efficiency and the message latency are influenced by the location of a station on the bus, the number of short messages, the number of priority levels, the message

Frederick Pensworth; Constance Hoyland; Ken Evers

1988-01-01

380

Modelling and Analysis of a High Speed Data Bus with Predicate/Transition Nets.  

National Technical Information Service (NTIS)

In this work predicate/transition nets (Pr/T-nets) are used in the modeling and analysis of the medium access control algorithm of a parallel high speed data bus, Frame Synchronized Ring (FSR-bus). Two Pr/T-net models of the bus are presented. One models ...

T. Pyssysalo

1994-01-01

381

Wireless field bus communication with software defined IR-UWB in a manufacturing environment  

Microsoft Academic Search

This paper elaborates a concept for a wireless field bus communication with software defined ultra wide band with impulse radio modulation (IR-UWB) in manufacturing environments. A wireless field bus offers an important improvement to the smart factory due to increasing requirements for connectivity, adaptability and flexibility. Former analysis showed the benefit of using UWB technology for the wireless field bus

T. Alpert; F. Lang; M. Gro?zing; M. Berroth

2010-01-01

382

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

Code of Federal Regulations, 2011 CFR

... false Standard No. 221; School bus body joint strength. 571.221 Section...221 Standard No. 221; School bus body joint strength. S1. Scope. This...establishes requirements for the strength of the body panel joints in school bus bodies....

2011-10-01

383

Analysis of Bus Maneuverability and Stability Impact Elements Based on Matlab  

Microsoft Academic Search

Bus dynamics is analyzed and dynamics model is established according to basic dynamic characteristics of bus. The corresponding computer simulation program is developed by using Matlab software. From practical view, structural parameters which are impacted by bus maneuverability and stability such as tire cornering stiffness, center of mass motion, around the Z axis moment of inertia and roll resistance coefficient

Hao Zhang; Xiansheng Li; Xuelian Zheng; Hongfei Liu

2010-01-01

384

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

Microsoft Academic Search

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

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

385

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

Microsoft Academic Search

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

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

386

49 CFR 571.217 - Standard No. 217; Bus emergency exits and window retention and release.  

Code of Federal Regulations, 2010 CFR

...inside and outside surfaces of the bus. (b) Concise operating...on the inside surface of the bus. These instructions shall be...centimeters and either red, white, or yellow in color, that when tested...inside surface of each school bus with one or more wheelchair...

2009-10-01

387

49 CFR 571.217 - Standard No. 217; Bus emergency exits and window retention and release.  

Code of Federal Regulations, 2010 CFR

...inside and outside surfaces of the bus. (b) Concise operating...on the inside surface of the bus. These instructions shall be...centimeters and either red, white, or yellow in color, that when tested...inside surface of each school bus with one or more wheelchair...

2010-10-01

388

Evaluation of Camera-Based Systems to Reduce Transit Bus Side Collisions. Final Report.  

National Technical Information Service (NTIS)

One of the major reasons that side crashes occur if the bus drivers are at fault is that the drivers cannot see another vehicles in the blind zones of the mirrors of the bus. This brings the bus driver into situations where he/she cannot see vehicles appr...

A. Kourtellis C. Lee M. Saxena P. Lin

2010-01-01

389

Electromagnetic profiling of a double decked bus using a scale model  

Microsoft Academic Search

This paper introduces the study of electromagnetic profiling for electrically large structures using scale models and outlines the study and use of radio frequency propagation and power distribution internally from a double decked bus to an external receiver. A scale model study of a double decked bus, examining the effect of antenna placement and internal structures within the bus on

Serenus Jeyakumar; David Linton; Mairtin. O'Droma

2011-01-01

390

Optimal Replacement of GMC Bus Engines: An Empirical Model of Harold Zurcher  

Microsoft Academic Search

This paper formulates a simple, regenerative, optimal-stopping model of bus-eng ine replacement to describe the behavior of Harold Zurcher, superinte ndent of maintenance at the Madison (Wisconsin) Metropolitan Bus Comp any. Admittedly, few people are likely to take particular interest in Harold Zurcher and bus engine replacement per se. The author focuses on a specific individual and capital good because

John Rust

1987-01-01

391

A simple and efficient bus management scheme that supports continuous streams  

Microsoft Academic Search

An efficient bandwidth management and access arbitration scheme for an I\\/O bus in a multimedia workstation is presented. It assumes that a multimedia workstation consists of a number of processing modules which are interconnected by a packet bus. The scheme is efficient in the sense that it allows the bus to support both continuous media transfers and regular random transactions

Saied Hosseini-Khayat; Andreas D. Bovopoulos

1995-01-01

392

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

SciTech Connect

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.

Not Available

2011-01-01

393

Predicting Bus Arrival Time on the Basis of Global Positioning System Data  

Microsoft Academic Search

The ability to obtain accurate predictions of bus arrival time on a real-time basis is a vital element to both bus operations control and passenger information systems. Several studies had been devoted to this arrival time prediction problem; however, few resulted in completely satisfactory algorithms. This paper presents a new system that can be used to predict the expected bus

Dihua Sun; Hong Luo; Liping Fu; Weining Liu; Xiaoyong Liao; Min Zhao

2007-01-01

394

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

ERIC Educational Resources Information Center

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…

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

395

Design, implementation, and operation of a class based batch queue scheduler for VAX/VMS  

SciTech Connect

Fermilab found that the standard VMS batch configuration options were inadequate for the job mix that exists on the Fermilab central computer facility VAX cluster. Accordingly, Fermilab designed and implemented a class based batch queue scheduler. This scheduler makes use of the standard VMS job controller and batch system. Users interact with the scheduler at job submission time by specification of CPU time limits and batch job characteristics. This scheduler allows Fermilab to make efficient use of our large heterogeneous VAX cluster which contains machines ranging from a VAX 780 to a VAX 8800. The scheduler was implemented using the VMS system services $GETQUI and $SNDJBC, without changes to the existing VMS job scheduler. As a result, the scheduler should remain compatible with future VMS versions. This session will discuss the design goals, implementation, and operational experience with Fermilab's class based batch queue scheduler.

Chadwick, K.

1988-05-20

396

Fair Queueing with Feedback-Based Policing: Promoting Fairness and Preventing Congestion Collapse in the Internet  

Microsoft Academic Search

End-to-end congestion control is an important reason why the Internet is robust, scalable and simple to use. Unfortunately, purely end-to-end congestion control algorithms are incapable of preventing the unfair bandwidth allocations and congestion col- lapse caused by unresponsive applications, which are becoming increasingly prevalent in the Internet. In this paper, we propose a new mechanism called Fair Queueing with Feedback-based

Célio Albuquerque; Tatsuya Suda; Brett J. Vickers

1999-01-01

397

An Active Queue Management for QoS Guarantee of the High Priority Service Class  

NASA Astrophysics Data System (ADS)

In this paper, we propose the active queue management mechanism (Active-WRED) for guaranteeing the quality of the high priority service class (VoIP or IPTV) in the multi-class traffic service environment. In the congestion situation, this mechanism increases the drop probability of the low priority traffic and reduces the drop probability of the high priority traffic; therefore it can guarantee the quality of the high priority service class from the poor quality by the packet loss.

Kim, Hyun Jong; Shim, Jae Chan; Kim, Hwa-Suk; Cho, Kee Seong; Choi, Seong Gon

398

Markov-modulated finite-source queueing models in evaluation of computer and communication systems  

Microsoft Academic Search

The present paper deals with a first-come, first-served (FCFS) queueing model to analyze the behaviour of a heterogeneous finite-source system with a single server. The sources and the server are assumed to operate in independent Markovian environments, respectively. Each request is characterized by its own exponentially distributed source and service time with parameter depending on the state of the corresponding

C. S. Kim

2003-01-01

399

Web server performance modeling using an M\\/G\\/1\\/K*PS queue  

Microsoft Academic Search

Performance modeling is an important topic in capacity planning and overload control for web servers. We present an M\\/G\\/1\\/K*PS queueing model of a web server. The arrival process of HTTP requests is assumed to be Poissonian and the service discipline is processor sharing. The total number of requests that can be processed at one time was limited to K. Closed

Jianhua Cao; Mikael Andersson; Christian Nyberg; Maria Kihl

2003-01-01

400

Queues with Service Times and Interarrival Times Depending Linearly and Randomly upon Waiting Times  

Microsoft Academic Search

We consider a modification of the standardG\\/G\\/1 queue with unlimited waiting space and the first-in first-out discipline in which the service times and interarrival times\\u000a depend linearly and randomly on the waiting times. In this model the waiting times satisfy a modified version of the classical\\u000a Lindley recursion. We determine when the waiting-time distributions converge to a proper limit and

Ward Whitt

1990-01-01

401

A VLSI sequencer chip for ATM traffic shaper and queue manager  

Microsoft Academic Search

The authors propose to control user traffic at two places in an asynchronous transfer model (ATM) network: at the user-network interface (UNI) by a traffic enforcer, and at the network-node interface (NNI) by a queue manager. The traffic enforcer adopted in this work contains a buffer to delay and reshape the violating cells that do not comply with some agreed-upon

H. Jonathan Chao; Necdet Uzun

1992-01-01

402

PERFORMANCE ANALYSIS OF CELL AND PACKET SWITCH WITH FINITE INPUT QUEUES AND ILPF SCHEDULING ALGORITHM  

Microsoft Academic Search

In this paper, packet loss probability performance in cell-based and packet-based switches with finite Input Queues (IQ) and iLPF scheduling algorithm are analysed. This algorithm has been proposed as a practical scheduling algorithm to achieve 100% throughput in cell-based switches. The scheduling algorithm is implemented in three cases: cell- based (CB-iLPF) switching, packet-based (PB-iLPF) switching and \\

Igor Radusinovic; Zoran Petrovic

403

APPROXIMATION OF THE MEAN WAITING TIME IN THE M\\/H2\\/s QUEUE  

Microsoft Academic Search

In this paper a closed formula to estimate the mean waiting time in the M\\/H2\\/s queue is presented. The proposed formula takes into account the first three moments of the H2 holding time distribution and is extremely easy to compute, while the accuracy is similar to other more complex approximations. The results presented here can be extended to calculate the

Francisco Barceló; Josep Paradells

1997-01-01

404

Heavy-traffic limits for waiting times in many-server queues with abandonment  

Microsoft Academic Search

We establish heavy-traffic stochastic-process limits for waiting times in many-server queues with customer abandonment. If the system is asymptotically critically loaded, as in the quality-and-efficiency-driven (QED) regime, then a bounding argument shows that the abandonment does not affect waiting-time processes. If instead the system is overloaded, as in the efficiency-driven (ED) regime, following Mandelbaum et al. [Proceedings of the Thirty-Seventh

Rishi Talreja; Ward Whitt

2009-01-01

405

Fair resource allocation in wireless networks using queue-length-based scheduling and congestion control  

Microsoft Academic Search

Abstrucl- We consider the problem of allocating resources (time slots, frequency, power, etc.) at a base station to many com- peting flows, where each flow is intended for a different receiver, The channel conditions may be time-varying and different for dif- ferent receivers. It is well-known that appropriately chosen queue- length based poticies are throughput-optimal while other policies based on

Atilla Eryilmaz; R. Srikant

2005-01-01

406

Applying adaptive virtual queue to improve the performance of the assured forwarding service  

Microsoft Academic Search

Recent research studies in over-provisioned networks have shown that the assured forwarding (AF) service in the current differentiated services (DiffServ) architecture fails to provide bandwidth assurance in some situations. The paper focuses on the situation where adaptive and non-adaptive traffic coexist in the same real queue at routers and the buffer management scheme treats the traffic of the same priority

X. Chang; Jogesh K. Muppala

2005-01-01

407

Target of Opportunity Observing in Queue Mode at the Gemini North Observatory  

NASA Astrophysics Data System (ADS)

The Gemini Observatories primarily operate a multi-instrument queue, with observers selecting observations that are best suited to weather and seeing conditions. Queue operations give higher ranked programs a greater chance for completion than lower ranked programs requesting the same conditions and instrument configuration. Queue observing naturally lends itself to Target of Opportunity (ToO) support since the time required to switch between programs and instruments is very short, and the staff observer is trained to operate all the available instruments and modes. Gemini Observatory has supported pre-approved ToO programs since beginning queue operations, and has implemented a rapid (less than 15 minutes response time) ToO mode since 2005. The rapid response ToO mode has thus far been exclusively utilized by the Gemini community for optical and near-IR follow-up of Gamma Ray Bursts (GRBs), primarily discovered by the Swift satellite. We discuss the ToO implementation at Gemini Observatory including the ToO user interface and the procedures followed by observatory staff astronomers once a ToO trigger is received. We present the statistics of 4 years of rapid ToOs at Gemini North Observatory, and the advances in our understanding of GRBs, their host galaxies and the intergalactic medium that this important mode has enabled. Finally we discuss recent changes in both software and policy to improve standard and rapid ToO support at the Gemini Observatories. The Gemini Observatory is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciìncia e Tecnologia (Brazil), and SECYT (Argentina)

Roth, Katherine; Price, P.; Gillies, K.; Walker, S.; Miller, B.

2009-01-01

408

Spacecraft ring-bus power system management scheme  

Microsoft Academic Search

This paper presents the results of studies which applies a multi-objective optimization function for the management of a solar based DC spacecraft network of the ring bus topology. The optimization function is utilized which features the objectives of optimizing the utilization of solar energy to continually meet the needs of the network while minimizing battery discharge current and current flows

J. A. Momoh; K. D'Arnaud; Wenjie Zheng

2010-01-01

409

Effect of homodyne crosstalk in WDM ring\\/bus networks  

Microsoft Academic Search

The effect of homodyne crosstalk, including both coherent and incoherent crosstalk, introduced by optical add\\/drop multiplexers in wavelength division multiplexing ring\\/bus networks is studied. It is found that the effect of coherent crosstalk cumulates quickly as the number of nodes through which an optical signal passes increases, while the effect of incoherent crosstalk remains the same. Our results show that

Yunfeng Shen; Chao Lu

2000-01-01

410

Torus-Ring-Bus Connected Hierarchic Parallel Machine  

Microsoft Academic Search

The increase of interconnecting wires is one of the serious problems of implementing a parallel processing system having over ten thousand processors. We have proposed a cluster architecture called a TRB (Torus-Ring-Bus) for these massive parallel systems. This architecture aims at both to decrease the interconnecting wires and increase the performance of numerical computations. In this paper, we describe the

Taku Itoh; Masaki Kohata

1996-01-01

411

Inductively Coupled Circuits with Spin Wave Bus for Information Processing  

Microsoft Academic Search

We describe a new approach to logic devices interconnection by the inductive coupling via a ferromagnetic film. The information among the distant devices is transmitted in a wireless manner via a magnetic field produced by spin waves propagating in the ferromagnetic film, referred to as the spin wave bus. As an alternative approach to the transistor-based architecture, logic circuits with

A. Khitun; M. Bao; J. Y. Lee; K. L. Wang D. W. Lee; S. Wang; Igor V. Roshchin

2007-01-01

412

Nano scale computational architectures with Spin Wave Bus  

Microsoft Academic Search

We propose and analyze a new kind of nano scale computational architectures using spin waves as a physical mechanism for device interconnection. Information is encoded into the phase of spin waves propagating in a ferromagnetic film — a Spin Wave Bus. We describe several possible logic devices utilizing spin waves. The performance of the proposed devices is illustrated by numerical

Alexander Khitun; Kang L. Wang

2005-01-01

413

Assessing technical inefficiency of bus transit with adjustment of accidents  

Microsoft Academic Search

In the light of occasional involvement of traffic accidents and of seldom costless to dispose such undesirable accidents, conventional data envelopment analysis (DEA) methods, which assume that traffic accidents are freely disposable in bus transit efficiency measurement, may not be appropriate. To rectify this shortcoming, this paper attempts to construct directional output distance function models to assess the technical inefficiency

Erwin T. J. Lin; Lawrence W. Lan

414

LARGE SCHOOL BUS SAFETY RESTRAINT EVALUATION - PHASE II  

Microsoft Academic Search

This paper details the National Highway Traffic Safety Administration's (NHTSA) continuing research and testing activities on large school bus safety restraints. This paper will discuss relative performance of compartmentalization, lap belt restraints and lap\\/shoulder belt restraints, as well as the effects of seat back height and seat spacing on the performance of these safety restraint strategies. Results of NHTSA's frontal

Jeffrey C. Elias; Lisa K. Sullivan; Linda B. McCray

415

Simulation research on the secondary regulating transmission system of bus  

Microsoft Academic Search

Hydrostatic transmission with secondary regulation is a new kind of hydrostatic transmission, which can regenerate inertial and gravitational energy of load. Based on deeply analyzing the working principles and energy-saving theory of bus secondary regulating transmission system, regenerating the transmission system's inertial energy by controlling constant torque was put forward. Considering large changes of the parameters of the transmission system

Zang Faye; Dai Ruquan

2009-01-01

416

Long School Bus Rides: Stealing the Joy of Childhood.  

ERIC Educational Resources Information Center

Every school day, hundreds of West Virginia children ride school buses much longer than state guidelines say they should. Under those guidelines, no elementary student should be on the bus more than 30 minutes one way, middle school students 45 minutes, and high school students 1 hour. In fall 1999, public hearings about school transportation…

Spence, Beth

417

High-Tech School Bus Teaches Students on the Road  

ERIC Educational Resources Information Center

|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…

Katims, Lauren

2011-01-01

418

Long School Bus Rides: Stealing the Joy of Childhood.  

ERIC Educational Resources Information Center

|Every school day, hundreds of West Virginia children ride school buses much longer than state guidelines say they should. Under those guidelines, no elementary student should be on the bus more than 30 minutes one way, middle school students 45 minutes, and high school students 1 hour. In fall 1999, public hearings about school transportation…

Spence, Beth

419

Compressed Natural Gas Bus Safety: A Quantitative Risk Assessment  

Microsoft Academic Search

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

Samuel Chamberlain; Mohammad Modarres

2005-01-01

420

Verification of an Audio Protocol with Bus Collision Using UPPAAL  

Microsoft Academic Search

In this paper we apply the tool Uppaal1 to an automatic analysis of a version of the Philips Audio Control Protocol with two senders and bus collision handling. This case study is significantly larger than the real-time\\/hybrid systems previously analysed by automatic tools. During the case study the tool Uppaal was extended with a new feature, committed locations, allowing efficient

Johan Bengtsson; W. O. David Griffioen; Kåre J. Kristoffersen; Kim Guldstrand Larsen; Fredrik Larsson; Paul Pettersson; Wang Yi

1996-01-01

421

What's Happening on the School Bus Performance Front?  

ERIC Educational Resources Information Center

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

Combs, Hanford L.

422

Legal Self-Defense after a Bus Crash.  

ERIC Educational Resources Information Center

After a South Carolina school bus accident, involving the death of an automobile driver, the district was faced with a lawsuit. Advises school administrators not to rely on police authorities to gather all the evidence but to compile a thorough school-system accident report, written in close cooperation with a school attorney. Lists report…

Wright, Ron

1992-01-01

423

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

ERIC Educational Resources Information Center

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

Marvin, Christine A.; Cline, Keely D.

2010-01-01

424

Universal serial bus based software attacks and protection solutions  

Microsoft Academic Search

Information security risks associated with Universal Serial Bus (USB) storage devices have been serious issues since 2003, which marked the wide adoption of USB technologies in the computing industry, especially in corporate networks. Due to the insecure design and the open standards of USB technologies, attackers have successfully exploited various vulnerabilities in USB protocols, USB embedded security software, USB drivers,

Dung Vu Pham; Ali Syed; Malka N. Halgamuge

2011-01-01

425

Design of City-Bus Intelligent Control System Framework  

Microsoft Academic Search

Intelligent public transportation is the most efficient method to solve city transportation problems such as public traffic jam, frequent traffic accident, traffic environment pollution and energy sources shortage etc. For designing city-bus intelligent system, the main body in ITS (intelligent transportation system), we analyzed the whole request of society and government, passenger, driver and center of monitoring and management. Based

Jian Hu; Gangyan Li

2006-01-01

426

Training Needs Analysis for Bus Depot Managers at GSRTC  

ERIC Educational Resources Information Center

|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…

Shah, Hardik; Gopal, Raj

2012-01-01

427

Implementation of a Walking School Bus: Lessons Learned  

ERIC Educational Resources Information Center

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

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

2009-01-01

428

School Bus Safety. An AS&U Roundtable.  

ERIC Educational Resources Information Center

A roundtable discussion of the issue of seat belts in school buses features United States Representative Peter H. Kostmayer, who has introduced a bill providing incentive grants to states to adopt and enforce laws requiring the use of seat belts in new school buses; three bus manufacturing executives; and two educators. (MLF)

American School and University, 1985

1985-01-01

429

Issues in School Bus Safety: Real or Red Herring?  

ERIC Educational Resources Information Center

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…

Leeds, Robin L.

1999-01-01

430

Research Says "No" to School Bus Seat Belts.  

ERIC Educational Resources Information Center

Presents factual data on research in school bus safety that shows that seat belts in school buses may actually be detrimental to students. Includes data from surveys and research tests and sources for additional information on seat belts in school buses. (MD)

Wineland, Charles L.

1986-01-01

431

Increased plasma homocysteine levels in shift working bus drivers  

PubMed Central

Background: Previous studies have indicated an association between shift work and cardiovascular disease. There is also considerable epidemiological evidence that hyperhomocysteinemia is an independent risk factor for cardiovascular disorders. Aims: To analyse plasma homocysteine levels in shift work bus drivers, and to investigate possible relations with sleep parameters and other biochemical factors. Methods: Blood samples were collected from 30 male shift working long-haul bus drivers in a Brazilian sample and analysed for plasma levels of homocysteine, folic acid, vitamin B12, and serum lipids. A group of 22 daytime workers, matched for age and body mass index served as controls. The incidence of mutations in the gene coding for methylene tetrahydrofolate, an enzyme which is related to hyperhomocysteinemia, was also assessed. Polysomnographic recordings were obtained from the target group. Results: Bus drivers showed significantly higher levels of plasma homocysteine than the control group (18.57 v 9.43 µM). Most of the other biochemical, behavioural, and molecular parameters did not differ between groups. Likewise, sleep parameters appeared to be within the normal range. Conclusions: The significantly increased plasma homocysteine levels in long-haul bus drivers did not appear to be secondary to other biochemical or behavioural problems in this group. These results suggest that hyperhomocysteinemia may be involved in the increased incidence of cardiovascular diseases observed in shift workers.

Martins, P; D'Almeida, V; Vergani, N; Perez, A; Tufik, S

2003-01-01

432

Power bus decoupling on multilayer printed circuit boards  

Microsoft Academic Search

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

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

1995-01-01

433

Progress on Improvements to a Hydrogen\\/Electric Hybrid Bus  

Microsoft Academic Search

The primary goal of the reported work is to extend the range of the bus in a cost-effective manner. Among the modifications underway are the development of a new engine, upgrading the power control system, rewiring critical elements, adapting a supercapacitor regenerative braking system, devising more effective changes to the hydrogen safety systems, and adding a high pressure gas storage

Y. Baghzouz; J. Fiene; J. Van Dam; L. Shi; E. Wilkinson; R. Boehm

434

Collision-Free Access Control for Computer Communication Bus Networks  

Microsoft Academic Search

This paper considers access control for local area computer communication networks. We propose two distributed access control schemes for a bus network. The schemes are simple and asynchronous, and provide for collision-free communication among ports. In addition, one of the schemes provides a bounded, guaranteed time to transmisidon for each port. We also show that this scheme is efficient in

Kapali P. Eswaran; V. Carl Hamacher; Gerald S. Shedler

1981-01-01

435

Bus detection device for the blind using RFID application  

Microsoft Academic Search

This paper outlines a bus detection mechanism for the blind in travelling from one place to another. In order to get transportation independently, the blind use auditory touched clues like walking stick or white cane. The limitation of the walking stick is that a blind person must come into close proximity with their surroundings to determine the location of an

Mohd Zikrul Hakim Noor; Ismarani Ismail; Mohammad Farid Saaid

2009-01-01

436

Effect of passenger position on fear of danger experienced during sudden bus stops.  

PubMed

The purpose of this study was to identify the effect of bus passengers' positions on their fear of danger when a bus stopped suddenly. A temporary bus running course with one bus stop was set up on the campus of the Tokyo University of Agriculture and Technology (TUAT). The bus ran the course 14 times with the bus stopping twice during the course, once at the bus stop and again just after re-starting from the bus stop. The driver was asked to brake more strongly than usual when stopping. Sixteen students (15 males and 1 female) between the ages of 18 and 21 years participated. In turn, all participants were asked to take 14 different postures in the bus. Participants were also asked to report their level of fear on a rating scale each time the bus stopped. The study showed that (1) passengers' fear of danger at the first sudden stop was typically higher than that at the second stop, (2) standing passengers who held hand straps experienced more fear than those who held fixed safety devices, (3) bus passengers sitting on the centre of the rear seat had a great risk of injury if the bus stopped suddenly, and (4) when passengers faced the window and stood transversely with respect to from the moving direction of the bus and the bus stopped suddenly, passengers' fear of danger was affected by the side of the bus on which they stood as well as which hand they used to grasp a safety device. PMID:20034314

Aoki, Takeo; Uetake, Teruo; Shimoda, Masahiro

2009-06-01

437

Predictive functional control for active queue management in congested TCP/IP networks.  

PubMed

Predictive functional control (PFC) as a new active queue management (AQM) method in dynamic TCP networks supporting explicit congestion notification (ECN) is proposed. The ability of the controller in handling system delay along with its simplicity and low computational load makes PFC a privileged AQM method in the high speed networks. Besides, considering the disturbance term (which represents model/process mismatches, external disturbances, and existing noise) in the control formulation adds some level of robustness into the PFC-AQM controller. This is an important and desired property in the control of dynamically-varying computer networks. In this paper, the controller is designed based on a small signal linearized fluid-flow model of the TCP/AQM networks. Then, closed-loop transfer function representation of the system is derived to analyze the robustness with respect to the network and controller parameters. The analytical as well as the packet-level ns-2 simulation results show the out-performance of the developed controller for both queue regulation and resource utilization. Fast response, low queue fluctuations (and consequently low delay jitter), high link utilization, good disturbance rejection, scalability, and low packet marking probability are other features of the developed method with respect to other well-known AQM methods such as RED, PI, and REM which are also simulated for comparison. PMID:18995853

Bigdeli, N; Haeri, M

2008-11-07

438

Packet marking function of active queue management mechanism: should it be linear, concave, or convex?  

NASA Astrophysics Data System (ADS)

Recently, several gateway-based congestion control mechanisms have been proposed to support the end-to-end congestion control mechanism of TCP (Transmission Control Protocol). In this paper, we focus on RED (Random Early Detection), which is a promising gateway-based congestion control mechanism. RED randomly drops an arriving packet with a probability proportional to its average queue length (i.e., the number of packets in the buffer). However, it is still unclear whether the packet marking function of RED is optimal or not. In this paper, we investigate what type of packet marking function, which determines the packet marking probability from the average queue length, is suitable from the viewpoint of both steady state and transient state performances. Presenting several numerical examples, we investigate the advantages and disadvantages of three packet marking functions: linear, concave, and convex. We show that, although the average queue length in the steady state becomes larger, use of a concave function improves the transient behavior of RED and also realizes robustness against network status changes such as variation in the number of active TCP connections.

Ohsaki, Hiroyuki; Murata, Masayuki

2004-10-01

439

Optoelectronic packaging for 16-channel optical backplane bus with VHOEs  

NASA Astrophysics Data System (ADS)

A novel 16-channel optical backplane bus with volume holographic optical elements (VHOEs), operating as diffraction grating beam alignment guides, was designed and fabricated for a high-performance computing system multi-slot bus. These thin film VHOEs were fabricated to diffract light beams for each bus slot into a glass wave-guiding plate (refractive index 1.52) for total internal reflection to other slot positions. Slot-to-slot optical alignment issues, including channel crosstalk and beam alignment tolerances, were computer modeled to optimize a low cost and simple optical packaging structure. For each slot position, a 4 × 8 element optical packaging plate was then fabricated to allow insertion of 16 VCSELs and 16 Photodiodes, each in an individual TO-46 can. Through the VHOE, the slot-to-slot fan-out received beam intensities were experimentally measured for each of the 16 channels and found to be in the range of 90 ?W ~ 150 ?W. This 90 ?W minimum fan-out power is 5dB greater than the receiver sensitivity requirement. In this study, the maximum 10 Gbps single channel bandwidth was tested and a 1.6 Gbps aggregate bandwidth was also demonstrated through a three slot 16-channel optical backplane bus. This aggregate bandwidth was limited by an electronic element in the receiver circuit (155 Mbps PD-TIA) and processor (100 Mbps FPGA). With the system's measured optical isolation of greater than 80dB, and suitably fast receiver electronics, simulation modeling indicates that Terabit per second bus data rates can be achieved in inexpensive, mechanically robust and reliable form factors.

Choi, J. H.; Bi, H.; Ellis, J.; Chen, R. T.

2007-03-01

440

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

SciTech Connect

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.

Eudy, L.; Chandler, K.

2011-03-01

441

Improving student bus-riding behavior through a whole-school intervention.  

PubMed Central

We describe a multicomponent intervention to improve bus-riding behavior of students attending an urban public school. The intervention was developed with technical assistance consultation that emphasized collaboration among students, school personnel, and bus drivers. The primary intervention procedures were identifying appropriate behaviors during transportation ("bus rules"), training bus drivers to deliver positive reinforcement, and rewarding student performance through a weekly school-based lottery. Disruptive bus behaviors, as measured by discipline referrals and suspensions, decreased with intervention relative to baseline phases in an ABAB reversal design. These positive results were maintained over the long term, with school personnel assuming responsibility for intervention in the absence of ongoing consultation.

Putnam, Robert F; Handler, Marcie W; Ramirez-Platt, Christina M; Luiselli, James K

2003-01-01

442

Phase Demodulation of DPSK Signals Using Dual-Bus Coupled Silicon Micro-Ring Resonator  

NASA Astrophysics Data System (ADS)

We demonstrate phase demodulation of 10-Gbps DPSK signals using a silicon micro-ring resonator with a radius of 10µm and with various coupling gaps for light of ?1550nm in wavelength. Influence of the Q factors and transmissions of the resonators on the response speed and power balance of the two output ports is discussed. Furthermore, temperature sensitivity on resonance peak was measured and we discuss its effect on practical demodulation application.

Kou, Rai; Park, Sungbong; Tsuchizawa, Tai; Fukuda, Hiroshi; Nishi, Hidetaka; Shinojima, Hiroyuki; Yamada, Koji

443

Cascaded battery energy storage system based on dual active bridges and a common DC bus  

Microsoft Academic Search

Along with the increasing system capacity, large-scaled energy storage systems are supposed to be connected into 10kV or higher networks. Urban network has strict criterions on power quality of the power electronic devices connected. Moreover, the occupancy and noise of industrial frequency transformers also become restraints to the promotion of urban network energy storage. For that reason, this paper proposes

Yiding Jin; Qiang Song; Wenhua Liu; Weixin Sun

2010-01-01

444

Grid-connected hybrid PV\\/wind power generation system with improved DC bus voltage regulation strategy  

Microsoft Academic Search

The objective of this paper is to propose an improved dc bus voltage regulation strategy for the grid-connected PV\\/Wind power generation system. The proposed dc bus voltage regulation strategy can reduce the variation of the dc bus voltage and the size of the dc bus capacitor bank, significantly. Also, the change of the injected ac current amplitude will be moderate

Yaow-Ming Chen; Chung-Sheng Cheng; Hsu-Chin Wu

2006-01-01

445

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

Microsoft Academic Search

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

Hiroyuki Yamauchi; Hironori Akamatsu; Tsutomu Fujita

1995-01-01

446

Development of a real-time simulator for electric vehicle with a Dual Energy Storage System  

Microsoft Academic Search

For verifying the strategy of the vehicle control unit(VCU), a real-time simulation environment needs to be established in advance. It is modified from our in-house simulator for the electric vehicle (EV) based on the hardware in-the-loop(HIL) structure and constrained by several communication devices, e.g. CAN bus, AI\\/O, DI\\/O, etc.. A dual energy storage system (DESS) has been modeled in this

Chien-Hsun Wu; Wu-Yang Sean; Yi-Hsuan Hung

2009-01-01

447

Neutronics parameters optimization of the improved dual-cooled waste transmutation blanket for FDS  

Microsoft Academic Search

The neutronic analyses of the improved dual-cooled waste transmutation blanket (I-DWTB) for the fusion-driven sub-critical system (FDS) with a neutron wall loading of 0.5 MW\\/cm2 are preformed on the basis of 3-D transport calculations with MCNP and 1-D burnup calculations with home-developed code BUS and the multi-group (175 neutron groups - 42 Gamma groups coupled) data library originated from the

S. L. Zheng; C. J. Gao; D. Z. Xu; X. X. Zhu; H. Lin; J. J. Li; Y. C. Wu

2003-01-01

448

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

PubMed Central

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.

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

2003-01-01

449

Homodyne crosstalk in WDM ring and bus networks  

Microsoft Academic Search

We examine the combined effects of coherent and incoherent crosstalk in wavelength-division multiplexed (WDM) ring and bus networks which use add-drop multiplexers. It is widely understood that incoherent crosstalk in these networks causes a fixed bit-error-rate (BER) door at the receiver. We show that coherent crosstalk causes a range of possible received powers. In combination with incoherent crosstalk, this leads

Sarah D. Dods; Jonathan P. R. Lacey; Rodney S. Tucker

1997-01-01

450

Torus-ring-bus connected highly parallel processor  

Microsoft Academic Search

A cluster structure interconnection network for massively parallel computers is proposed. Each processor is connected to a one-dimensional ring-bus network in a cluster, and each cluster is connected to a two-dimensional torus network. Basic network performance is estimated by software simulations for two communication patterns, namely, nearest neighbor communication and general communication. The architecture of a prototype machine that is

M. Kohata; T. Itoh; Y. Miyagaki

1993-01-01

451

Temporal coupled mode theory in ring-bus-ring configuration  

Microsoft Academic Search

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

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

2010-01-01

452

Parallel spaceborne fiber optic data bus physical layer  

Microsoft Academic Search

Optical Networks Inc. has developed and demonstrated a set of space-flight worthy, 12-channel fiber optic transmitter and receiver modules capable of providing data bandwidths up to 1 Gbps. This is accomplished using radiation tolerant commercial off-the-shelf (COTS) optical and electronic components. The parallel spaceborne fiber optic data bus (SFODB) implementation uses ten out of the available twelve fiber optic channels

Charles H. Chalfant; Fred J. Orlando; P. J. Parkerson

1998-01-01

453

Magnetic cellular nonlinear network with spin wave bus  

Microsoft Academic Search

We describe and analyze a magnetic cellular nonlinear network using spin waves for information exchange. The network consists of magneto-electric cells integrated onto a common ferromagnetic film-spin wave bus. A magneto-electric cell is an artificial multiferroic comprising piezomagnetic and piezoelectric materials, which electric and magnetic polarizations entangled via the magneto-electric coupling. A bit of information is encoded into the cell's

Alexander Khitun; Mingqiang Bao; Kang L. Wang

2010-01-01

454

Structure and Metrology for an Analog Testability Bus  

Microsoft Academic Search

This paper gives a proposal for an analog testability bus that could be used as the basis for a standard such as IEEE P1149.4. The proposed testability structure is imposed on the I\\/O pin cells of the analog and mixed technology ICs. It is a superset of the existing IEEE\\/ANSI 1149.1 testability standard for digital ICs and is intended to

Kenneth P. Parker; John E. Mcdermid; Stig Oresjo

1993-01-01

455

A GPS-Based On-Demand Shuttle Bus System  

Microsoft Academic Search

We propose the implementation of an on-demand system to serve requests to ride shuttles on a university campus. Assuming that each client and each shuttle bus has a GPS device, we devise two online algorithms: the k-means based algorithm, and the general pool-based algorithm. The former has two components: the first deals with the problem of assigning requests to shuttles,

Maria Vanina; Martinez Gerardo; I. Simari; Carlos D. Castillo; Nir J. Peer

456

OPTIMIZATION MODEL FOR LARGE-SCALE BUS TRANSIT SCHEDULING PROBLEMS  

Microsoft Academic Search

A procedure is presented for solving real-world large-scale multiple depot vehicle scheduling (MDVS) problems considering the route time constraints (RTCs). The procedure is applied to some test problems and then to a real-world problem. The real-world problem is the transit bus scheduling problem of the mass transit administration (MTA) in Baltimore, Maryland. The RTCs are added to the MDVS problem

Mohamadreza Banihashemi; Ali Haghani

2000-01-01

457

A serial hybrid bus with methanol-hydrogen engine  

Microsoft Academic Search

Hydrogen energy vehicle has become one of the key directions in the field of electric vehicle research and development worldwide. Hydrogen energy vehicles include three kinds such as fuel cell vehicle, hydrogen ICE vehicle and methanol-hydrogen engine vehicle. The paper presents a new kind of serial hybrid bus with an effective methanol-hydrogen engine. The methanol-hydrogen engine is a traditional engine

Liqing Sun; Ruchuan Liang; Qingcai Wang

2008-01-01

458

Child pedestrian injuries at tram and bus stops  

Microsoft Academic Search

In order to analyse these injuries and to create guidelines for prevention, injuries at bus or tram stops were analysed retrospectively. Medical records were analysed and questionnaires were sent to the parents in order to obtain detailed information about the mode and physical sequelae or post-traumatic behavioural disturbances of the injury.Thirty children of a median age of 9.5 years (2.7–15.3

R Unger; C Eder; J. M Mayr; J Wernig

2002-01-01

459

Spoken and Multimodal Bus Timetable Systems: Design, Development and Evaluation  

Microsoft Academic Search

We present three speech-based bus timetable systems with different approaches. The first system had open user-initiative dialogues aiming at natural interaction. The user tests re- vealed several problems with this approach, and we devel- oped solutions from multiple perspectives to overcome the problems. The second system focuses on task-oriented sys- tem-initiative dialogues, and contains a multimodal interface for smart mobile

Markku Turunen; Jaakko Hakulinen; Esa-Pekka Salonen; Anssi Kainulainen; Leena Helin

460

FLEXIBLE FUZZY PRIORITY SCHEDULING OF THE CAN BUS  

Microsoft Academic Search

With the increasing complexity of distributed real-time systems, the need for improved CAN bus performance is continually increasing. Nor- mally, a scheduling scheme with static-priority has low network schedula- bility\\/utilization; while using dynamic priority will improve the QoS of the network at the cost of a narrow service range or a high overhead, compared with the fixed priority scheduling schemes.

Tao Bai; Li-sheng Hu; Zhiming Wu; Genke Yang

2005-01-01

461

A set partitioning reformulation of a school bus scheduling problem  

Microsoft Academic Search

We present an integer programming model for the integrated optimization of bus schedules and school starting times, which\\u000a is a single-depot vehicle scheduling problem with additional coupling constraints among the time windows. For instances with\\u000a wide time windows the linear relaxation is weak and feasible solutions found by an ILP solver are of poor quality. We apply\\u000a a set partitioning

Armin Fügenschuh

462

Design of robot platform based on CAN bus  

Microsoft Academic Search

The modular designed by robotic platform for pluggable. The circuit module connected via CAN bus can reduce the complexity of the robot control system design and increase the reliability and flexibility. Robot platform uses a distributed circuit control structure based on the 32-bit ARM Cortex-M3 development of STM32 series chips, which could meet the actual needs by adding modules, such

Zhijie Lin; Tieliu Wang; Qiang Gao; Yahui Liu

2011-01-01

463

IRCOMM: spacecraft free-space optical bus development  

Microsoft Academic Search

This paper summarizes the on-going work at the Johns Hopkins University Applied Physics Laboratory (JHU\\/APL) towards implementation of a free-space optical bus for small spacecraft applications. After reviewing the current state of the art as well as previous work at JHU\\/APL, a comparison of several protocols, including USB, RS232, 10Mbit Ethernet (IEEE 802.3) is summarized, with Ethernet being the chosen

R. C. Meitzler; W. Schneider; R. Conde

2005-01-01

464

Pumped two-phase ammonia thermal bus test bed  

NASA Astrophysics Data System (ADS)

Future large spacecraft such as the Space Station will have high power dissipations and long heat transport distances. The combination of these two requirements dictate the need for a new heat transport technology. NASA-JSC has developed the concept of a two phase thermal bus in which the working fluid is evaporated at the heat collection site and is condensed at the heat rejection site. This provides a nearly isothermal system at lower pumping powers than current single phase systems. Boeing has developed a two-phase thermal bus testbed using ammonia working fluid. This testbed uses a Sundstrand rotary fluid management device (RFMD) to provide fluid pumping and liquid-vapor phase management. Overall heat transport capacity is 25 kW. This internally funded testbed is being used for thermal bus heat exchanger characterization and critical component life tests in an ammonia environment. Currently, the testbed has been assembled, proof-pressure tested, leak tested, and checked out. Heat exchanger performance tests are underway.

McHale, Michael P.; Goo, Steve D.; Pizzichemi, J. C.

1987-07-01

465

Pilot Survey of Subway and Bus Stop Noise Levels  

PubMed Central

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.

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

2006-01-01

466

Predictors of stress-related illness in city bus drivers.  

PubMed

This study examines the relation between stress and illness among bus drivers in a large American city. Several factors are identified that predict stress-related ill health for this occupational group. Canonical correlation techniques are used to combine daily work stress and recent stressful life events into a single life/work stress variate. Likewise, somatic symptoms and serious illness reports are combined into a single canonical illness variate. This procedure simplifies the analysis of multiple stress and illness indicators and also permits the statistical control of potential contaminating influences on stress and illness measures (eg, neuroticism). Discriminant function analysis identified four variables that differentiate bus drivers who get ill under high stress (N = 137) from those who remain healthy under stress (N = 137). Highly stressed and ill bus drivers use more avoidance coping behaviors, report more illness in their family medical histories, are low in the disposition of "personality hardiness," and are also low in social assets. The derived stepwise discriminant function correctly classified 71% of cases in an independent "hold-out" sample. These results suggest fruitful areas of attention for health promotion and stress management programs in the public transit industry. PMID:2668455

Bartone, P T

1989-08-01

467

The transient analysis of the queue-length distribution in the batch arrival system with N-policy, multiple vacations and setup times  

NASA Astrophysics Data System (ADS)

A batch arrival queueing system of the MX/G/1 type with unlimited queue is considered. After each busy period the server begins a multiple vacation period, consisting of independent single vacations, when the service process is blocked. The server begins successive single vacations as far as at the end of one of them the number of customers waiting in the queue equals at least N. The service of the first customer after the vacation period is preceded by a setup time. The analysis of the queue-size distribution on the first vacation cycle is directed to the analysis of the same characteristic in the corresponding ''usual'' system with unremovable server on its first busy period. The renewal-theory approach is used to obtain results in the general case. As main result the explicit representation for the LT of queue-size distribution is derived for the original system.

Kempa, Wojciech M.

2010-10-01

468

Effect of the traffic shaping function of the EF class in a DiffServ queue architecture  

NASA Astrophysics Data System (ADS)

An integrated IP (Internet Protocol) network that can handle leased-line, voice, and data traffic, offers great advantages in simplifying the networks of communication carriers and reducing network costs compared with separate service-specific networks. A key issue of such integrated IP networks will be to design a router that can efficiently handle each type of traffic strictly according to its QoS (Quality of Service). Diffserv (Differentiated Services) is a popular solution to handling multiple QoSs, so most routers tend to support it. In this paper, we propose a new DiffServ queue architecture featuring multiple EF (Expedited Forwarding) queues with traffic shaping functions. Because each EF queue has a traffic shaper, its QoS can be controlled without affecting other EF traffic. For example, when the leased line traffic is assigned to the first EF class and VoIP (Voice over IP) traffic to the second EF class, the VoIP traffic is transferred with high QoS even if the leased line traffic has bursty characteristics. This queue architecture can provide a low-latency, assured bandwidth for both leased-line and VoIP traffic. We evaluated the traffic characteristics of VoIP traffic by simulating this queue architecture using various bandwidths and voice codec types. The results indicate that this queuing mechanism can achieve lower latency and better QoS control than the usual DiffServ queue architecture without traffic shaping. The benefits of traffic shaping are more noticeable with low-bandwidth traffic.

Kawabata, Akio; Sakaguchi, Takeshi; Yamamoto, Susumu; Shimizu, Shigeki; Nishikido, Jun; Komura, Hisashi

2002-09-01

469

Light Rail Lite or Cost-Effective Improvements to Bus Service? Evaluating Costs of Implementing Bus Rapid Transit  

Microsoft Academic Search

Bus rapid transit (BRT) is growing rapidly in popularity because it is viewed widely as an efficient and effective means to improve both transit service and patronage. This paper argues that two distinct views of BRT are emerging: (a) BRT as a new form of high-speed, rubber-tired, rail-like rapid transit and (b) BRT as a cost-effective way to upgrade both

Daniel B. Hess; Brian D. Taylor; Allison C. Yoh

2005-01-01

470

A queueing problem with correlated arrivals and correlated phase-type service zur theorie des rangtests  

Microsoft Academic Search

Summary  This paper studies the steady-state behaviour of a discrete-time, single-channel, first-come-first-served queueing problem\\u000a wherein (i) the arrivals at two consecutive time-marks are correlated (ii) the service is accomplished in phases and (iii)\\u000a the completion of phases at two consecutive time-marks are correlated. The probability generating function (p.g.f.) of the\\u000a number of phases waiting and in service is obtained. Further, the

K. Murari

1972-01-01

471

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

SciTech Connect

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

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

1997-05-01

472

A PRACTICAL STUDY ON APPLICABILITY OF THE INCENTIVE SUBSIDY TO BUS NETWORK IN KUMAMOTO CITY  

NASA Astrophysics Data System (ADS)

Recently, the number of passenger of public bus services in Japan tends to decrease due to the motorization. This condition leads to a severe management situation, including in Kumamoto City. Since 1984, the deficit of bus companies operation in provision of bus services in Kumamoto has been covered by Kumamoto City Government on the basis of lines subsidy, and the city allocated a number of subsidy of about 200 million yen in 2007. Currently, The Kumamoto city government plans to reduce the amount of subsidy to bus companies by introducing the giving of incentive to bus companies in order to trim bus company deficit. This study aims to construct the mathematical model of the incentive reward and apply the model to realignment of buses lines networks in Kumamoto Metropolitan Area.

Mizokami, Shoshi; Fujimi, Toshio; Hirano, Toshihiko

473

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

SciTech Connect

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.

Eudy, L.; Chandler, K.

2013-01-01

474

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

SciTech Connect

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.

Eudy, L.; Chandler, K.

2012-05-01

475

Research and Development of an Intelligent Temperature-Measuring System Based on 1Wire Bus  

Microsoft Academic Search

Through the research on stratum freeze construction, and based on monitoring the application environment of long-distance stratum freezing in coal-mine construction, temperature monitoring method of 1-wire bus was proposed. According to the 1-wire bus technology and theory, the characteristic of time signaling conveyance was analyzed, the 1-wire bus drive circuit controlled by SCM was designed, and a new generation of

Hongmei Xue

2008-01-01

476

A Model-Based Design Process for the SegBus Distributed Architecture  

Microsoft Academic Search

We discuss a design process for a custom distributed platform, namely the SegBus segmented bus architecture. The main emphasis of this work is on how different steps of the process are interconnected and how they are supported by the associated tool chain. We place the SegBus design process in the context of the model-driven architecture (MDA) paradigm, in order to

Dragos Truscan; Tiberiu Seceleanu; Johan Lilius; Hannu Tenhunen

2008-01-01

477

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

Microsoft Academic Search

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

L. Eudy; K. Chandler

2011-01-01

478

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

Microsoft Academic Search

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

L. Eudy; K. Chandler

2011-01-01

479

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

Microsoft Academic Search

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

L. Eudy; K. Chandler

2012-01-01

480

Zero-Crosstalk Bus Line Structure for Global Interconnects in Si Ultra Large Scale Integration  

NASA Astrophysics Data System (ADS)

In this paper, we propose a novel technique for achieving high-density, high-speed and low-power on-chip bus lines using differential transmission lines. The feasibility of this technique is discussed with a two-dimensional electromagnetic simulator (Ansoft 2D Extractor) and time-domain measurements. Results show that the proposed bus line can transmit at over 12 Gbps. The proposed bus line can reduce wiring area by 30% compared with a conventional co-planar line.

Kimura, Makoto; Ito, Hiroyuki; Sugita, Hideyuki; Okada, Kenichi; Masu, Kazuya

2006-06-01

481

Considerations in applying power bus protection schemes to industrial and IPP systems  

Microsoft Academic Search

Increases in fault current levels and in-plant generation installations have necessitated further discussions on bus protection. This paper involves such discussions and deliberates the need for bus protection in medium-voltage systems. It discusses considerations for the applications of relay schemes and current transformers to present-day bus-bar protection. The importance of examining current transformer saturation is presented. Current transformers transient cases

Rasheek M. Rifaat

2004-01-01

482

Power-bus decoupling with embedded capacitance in printed circuit board design  

Microsoft Academic Search

This paper experimentally investigates the effectiveness of embedded capacitance for reducing power-bus noise in high-speed printed circuit board designs. Boards with embedded capacitance employ closely spaced power-return plane pairs separated by a thin layer of dielectric material. In this paper, test boards with four embedded capacitance materials are evaluated. Power-bus input impedance measurements and power-bus noise measurements are presented for

Minjia Xu; Todd H. Hubing; Juan Chen; Thomas P. Van Doren; James L. Drewniak; Richard E. DuBroff

2003-01-01

483

Superconducting link bus design for the accelerator project for upgrade of LHC  

NASA Astrophysics Data System (ADS)

The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. FermiNational Accelerator Laboratory in collaboration with Brookhaven National Laboratorywas developing sub-systems for the upgrade of the LHC final focus magnet systems. Partof the upgrade called for various lengths of superconducting power transmission linesknown as Superconducting (SC) Links which were up to 100 m long. The SC Linkelectrically connects the current leads in the Distribution Feed Boxes to the interactionregion magnets. The SC Link is an extension of the magnet bus housed within a cryostat.The present concept for the bus consists of 22 power cables, 4 × 13 kA, 2 × 7 kA, 8 × 2.5kA and 8 × 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus designpotentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus duringinstallation at CERN. The round bus is very flexible and is suitable for pulling through thecryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

Nobrega, Alfred; Brandt, Jeff; Cheban, Sergey; Feher, Sandor; Kaducak, Mark; Kashikhin, Vadim; Peterson, Thomas J.

2012-06-01

484

Heisenberg spin bus as a robust transmission line for quantum-state transfer  

NASA Astrophysics Data System (ADS)

We study quantum-state transfer (QST) through a strongly coupled antiferromagnetic spin chain (acting as a spin bus), between weakly coupled external qubits. By treating the weak coupling as a perturbation, we find that QST is enabled specifically by the second-order terms in the perturbative expansion. We show that QST is robust against disorder in the couplings, either within the bus or to the external qubits. We find that the protocol works when the qubits are attached to any node on an even-size bus or to the antiferromagnetic nodes on an odd-size bus. The optimal time for QST is found to depend nonmonotonically on qubit separation.

Oh, Sangchul; Wu, Lian-Ao; Shim, Yun-Pil; Fei, Jianjia; Friesen, Mark; Hu, Xuedong

2011-08-01

485

Development of Flexible Standard Bus for ISAS/JAXA Small Scientific Satellite Series  

NASA Astrophysics Data System (ADS)

This paper describes design and current developing status of a flexible standard bus system for a new series of small scientific satellites planned in the Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA). The satellite series are called SPRINT series, which stands for “Small space science Platform for Rapid INvestigation and Test”. First, features realizing a flexible standard bus are mentioned. Design concepts such as alternative options and selectable options are introduced. Second, the current status of the standard bus and SPRINT-A, which is the first satellite of SPRINT series using the standard bus and planed to be launched in 2013, is explained.

Nakaya, Koji; Fukuda, Seisuke; Sakai, Shin-Ichiro; Yamazaki, Atsushi; Uemizu, Kazunori; Toriumi, Tsuyoshi; Junko Takahashi; Maehara, Masaki; Okahashi, Takakazu; Shujiro Sawai, And

486

Superconducting link bus design for the accelerator project for upgrade of LHC  

SciTech Connect

The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. Fermi National Accelerator Laboratory in collaboration with Brookhaven National Laboratory was developing sub-systems for the upgrade of the LHC final focus magnet systems. Part of the upgrade called for various lengths of superconducting power transmission lines known as SC Links which were up to 100 m long. The SC Link electrically connects the current leads in the Distribution Feed Boxes to the interaction region magnets. The SC Link is an extension of the magnet bus housed within a cryostat. The present concept for the bus consists of 22 power cables, 4 x 13 kA, 2 x 7 kA, 8 x 2.5 kA and 8 x 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus design potentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus during installation at CERN. The round bus is very flexible and is suitable for pulling through the cryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

Nobrega, F.; Brandt, J.; Cheban, S.; Feher, S.; Kaducak, M.; Kashikhin, V.; Peterson, T.; /Fermilab

2010-08-01

487

Superconducting link bus design for the accelerator project for upgrade of LHC  

SciTech Connect

The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. Fermi National Accelerator Laboratory in collaboration with Brookhaven National Laboratory was developing sub-systems for the upgrade of the LHC final focus magnet systems. Part of the upgrade called for various lengths of superconducting power transmission lines known as SC Links which were up to 100 m long. The SC Link electrically connects the current leads in the Distribution Feed Boxes to the interaction region magnets. The SC Link is an extension of the magnet bus housed within a cryostat. The present concept for the bus consists of 22 power cables, 4 x 13 kA, 2 x 7 kA, 8 x 2.5 kA and 8 x 0.6 kA bundled into one bus. Different cable and strand possibilities were considered for the bus design including Rutherford cable. The Rutherford cable bus design potentially would have required splices at each sharp elbow in the SC Link. The advantage of the round bus design is that splices are only required at each end of the bus during installation at CERN. The round bus is very flexible and is suitable for pulling through the cryostat. Development of the round bus prototype and of 2 splice designs is described in this paper. Magnetic analysis and mechanical test results of the 13 kA cable and splices are presented.

Nobrega, F.; Brandt, J.; Cheban, S.; Feher, S.; Kaducak, M.; Kashikhin, V.; Peterson, T.; /Fermilab

2011-06-01

488

On Dual Configurational Forces  

Microsoft Academic Search

The dual conservation laws of elasticity are systematically re-examined by using both Noether's variational approach and Coleman–Noll–Gurtin's thermodynamics approach. These dual conservation laws can be interpreted as the dual configurational force, and therefore they provide the dual energy–momentum tensor. Some previously unknown and yet interesting results in elasticity theory have been discovered. As an example, we note the following duality

Shaofan Li; Anurag Gupta

2006-01-01

489

The ins and outs of terrorist bus explosions: Injury profiles of on-board explosions versus explosions occurring adjacent to a bus.  

PubMed

BACKGROUND: Terrorist explosions occurring in varying settings have been shown to lead to significantly different injury patterns among the victims, with more severe injuries generally arising in confined space attacks. Increasing numbers of terrorist attacks have been targeted at civilian buses, yet most studies focus on events in which the bomb was detonated within the bus. This study focuses on the injury patterns and hospital utilisation among casualties from explosive terrorist bus attacks with the bomb detonated either within a bus or adjacent to a bus. METHODS: All patients hospitalised at six level I trauma centres and four large regional trauma centres following terrorist explosions that occurred in and adjacent to buses in Israel between November 2000 and August 2004 were reviewed. Injury severity scores (ISS) were used to assess severity. Hospital utilisation data included length of hospital stay, surgical procedures performed, and intensive care unit (ICU) admission. RESULTS: The study included 262 victims of 22 terrorist attacks targeted at civilian bus passengers and drivers; 171 victims were injured by an explosion within a bus (IB), and 91 were injured by an explosion adjacent to a bus (AB). Significant differences were noted between the groups, with the IB population having higher ISS scores, more primary blast injury, more urgent surgical procedures performed, and greater ICU utilisation. Both groups had percentages of nearly 20% for burn injury, had high percentages of injuries to the head/neck, and high percentages of surgical wound and burn care. CONCLUSIONS: Explosive terrorist attacks detonated within a bus generate more severe injuries among the casualties and require more urgent surgical and intensive level care than attacks occurring adjacent to a bus. The comparison and description of the outcomes to these terrorist attacks should aid in the preparation and response to such devastating events. PMID:23490317

Golan, Ron; Soffer, Dror; Givon, Adi; Peleg, Kobi

2013-03-11

490

Handover Management for VoWLAN Based on Estimation of AP Queue Length and Frame Retries  

NASA Astrophysics Data System (ADS)

Switching a communication path from one Access Point (AP) to another in inter-domain WLANs is a critical challenge for delay-sensitive applications such as Voice over IP (VoIP) because communication quality during handover (HO) is more likely to be deteriorated. To maintain VoIP quality during HO, we need to solve many problems. In particular, in bi-directional communication such as VoIP, an AP becomes a bottleneck with the increase of VoIP calls. As a result, packets queued in the AP buffer may experience a large queuing delay or packet losses due to increase in queue length or buffer overflow, thereby causing the degradation of VoIP quality for the Mobile Nodes (MNs) side. To avoid this degradation, MNs need to appropriately and autonomously execute HO in response to the change in wireless network condition, i.e., the deterioration of wireless link quality and the congestion state at the AP. In this paper, we propose an HO decision strategy considering frame retries, AP queue length, and transmission rate at an MN for maintaining VoIP quality during HO. Through simulation experiments, we then show that our proposed method can maintain VoIP quality during HO by properly detecting the wireless network condition.

Niswar, Muhammad; Kashihara, Shigeru; Tsukamoto, Kazuya; Kadobayashi, Youki; Yamaguchi, Suguru

491

Reproductive queue without overt conflict in the primitively eusocial wasp Ropalidia marginata.  

PubMed

Colonies of the primitively eusocial wasp Ropalidia marginata consist of a single egg layer (queen) and a number of non-egg-laying workers. Although the queen is a docile individual, not at the top of the behavioral dominance hierarchy of the colony, she maintains complete reproductive monopoly. If the queen is lost or removed, one and only one of the workers [potential queen (PQ)] becomes hyperaggressive and will become the next queen of the colony. The PQ is almost never challenged because she first becomes hyperaggressive and then gradually loses her aggression, develops her ovaries, and starts laying eggs. Although we are unable to identify the PQ when the queen is present, she appears to be a "cryptic heir designate." Here, we show that there is not just one heir designate but a long reproductive queue and that PQs take over the role of egg-laying, successively, without overt conflict, as the queen or previous PQs are removed. The dominance rank of an individual is not a significant predictor of its position in the succession hierarchy. The age of an individual is a significant predictor, but it is not a perfect predictor because PQs often bypass older individuals to become successors. We suggest that such a predesignated reproductive queue that is implemented without overt conflict is adaptive in the tropics, where conspecific usurpers from outside the colony, which can take advantage of the anarchy prevailing in a queenless colony and invade it, are likely to be present throughout the year. PMID:22908278

Bang, Alok; Gadagkar, Raghavendra

2012-08-20

492

[Musculoeskeletal symptoms in bus drivers of a university institution].  

PubMed

Musculoskeletal symptoms (MSDs) in bus drivers have been associated to the inadequate conditions of the work station. The occurrence of MES was determined in the total population of bus drivers of a public university (N = 35), and these were related with the work station, the posture static load, age, BMI, worked days and the number of years in the position. In this study, the age range was between 27 and 56 years. The standardize Nordic Musculoskeletal Questionnaire for the determination of the MSDs, the method of the Regie National Des Usines Renault to measure the static postural load and a questionnaire to collect information of the bus working conditions were applied. The mean (X +/- SD) age was 39 +/- 1.94 years and the body mass index (BMI) was 31 +/- 1.95 Kg/m2. The MSDs were associated significantly to the BMI (rs = 0.895 and p < 0.05). There was a high incidence of MSDs (94%) with more occurrences in neck (69%), lower back (60%), superior back (57%) and knees (43%). Pain of strong intensity, located in the lower back and knees, was the main symptom. These findings can be related with the risks at the work station, such as absence of head support, lumbar support, non sliding seat and inadequate conditions of the labor environment: vibration and noise. There was neither association nor correlation of MSDs and the postural static load, or with the others variables in study. The results suggest that inadequate conditions of the work stations as well as the BMI, dominated the occurrence of MSDs. PMID:22978045

Fernández-D'Pool, Janice; Vélez, Fanny; Brito, Angel; D'Pool, César

2012-06-01

493

DIMETHYL ETHER (DME)-FUELED SHUTTLE BUS DEMONSTRATION PROJECT  

SciTech Connect

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. The 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 laboratory studies have included work with a Navistar V-8 turbodiesel engine, demonstration of engine operation on DME-diesel blends and instrumentation for evaluating fuel properties. The field studies have involved performance, efficiency and emissions measurements with the Champion Motorcoach ''Defender'' shuttle bus which will be converted to DME-fueling. The results include baseline emissions, performance and combustion measurements on the Navistar engine for operation on a federal low sulfur diesel fuel (300 ppm S). Most recently, they have completed engine combustion studies on DME-diesel blends up to 30 wt% DME addition.

Elana M. Chapman; Shirish Bhide; Jennifer Stefanik; Andre L. Boehman; David Klinikowski

2003-04-01

494

Hardware Engines for Bus Encryption: A Survey of Existing Techniques  

Microsoft Academic Search

Abstract The widening,spectrum,of applications and services provided by portable and embedded,devices bring a new dimension,of concerns,in security. Most,of those embedded systems (pay-TV, PDAs, mobile phones, etc…) make use of external memory. As a result, the main problem,is that data and,instructions are constantly exchanged,between,memory,(RAM) and CPU in clear form on the bus. This memory,may,contain confidential data like commercial software or private

Reouven Elbaz; Lionel Torres; Gilles Sassatelli; Pierre Guillemin; C. Anguille; Michel Bardouillet; Christian Buatois; Jean-baptiste Rigaud

2007-01-01

495

Common Spacecraft Bus for Earth Science Decadal Survey Missions  

NASA Astrophysics Data System (ADS)

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 while maintaining maximum commonality in the bus design. Satellite missions in Tier 1 of the Decadal Survey are missions with a launch period beginning in 2014. Four missions are planned and will measure climate change by examining solar and earth radiation, soil moisture and freeze/thaw cycles, ice sheet height differences, surface and ice sheet deformation from natural hazards, and vegetation structure (SMAP, ICESat-2, CLARREO, and DESDynI). Our study goals and objectives were: Develop a Common Spacecraft Bus (CSB) that incorporates the defined CPIF that can be configured to meet the individual Tier I mission specific requirements with minimal impacts or changes; Develop a efficient Assembly, Integration and Test (AI&T) flow and program schedule that can accommodate multiple Observatory level spacecraft processing and provide the flexibility to respond to program changes and other schedule perturbations; Develop a ROM cost for the CSB program approach, based on the reference design and schedules; Evaluate the CSB capability to host payloads of opportunity on the Tier I spacecraft; Evaluate the CSB capability to host the Tier II missions and what changes are required from the Tier I CSB We concluded: CSB approach for Tier I missions is feasible with very good synergy; Program Execution and AI&T approaches can be defined to take maximum advantage of CSB program approach and meet required launch readiness dates; ROM cost analysis indicates that a CSB approach is viable and offers substantial savings over separate procurements The Common Spacecraft Bus Architecture has flexibility, resources and capabilities to support beyond the Tier I Missions. There is additional CSB capability that could accommodate Payloads of Opportunity (PLO’s) on the Tier I missions - Complex Tier I operational, pointing, and field of view constraints indicate that PLO’s will need to be mostly passive and have limited additional constraints - Need to be cautious that PLO modifications for individual missions do not move away from the CSB approach; The CSB architecture has the capability to support two of the five Tier II missions; The CSB can be adapted to other LEO missions besides the Earth Science TIER I and II missions (space weather, helio/astrophysics, surveillance, etc.)

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

2010-12-01

496

Fuel consumption and exhaust emissions from a heavy-duty hybrid bus. Interim report  

SciTech Connect

The introduction of prototype heavy-duty hybrid vehicles introduces a number of challenges in assessing emissions performance compared to conventionally powered diesel or gasoline-fueled, heavy-duty vehicles. Difficulty is encountered because the engine may be operated on an intermittent basis (as a function of load or state of charge of the energy storage system) and in a narrow speed/load range. Therefore, in this project, heavy-duty chassis dynamometer emission measurements were used to benchmark the fuel consumption and exhaust emissions of a heavy-duty hybrid vehicle against a conventionally powered vehicle. The hybrid bus was powered with a CNG-fueled, VW 2.0L engine. Exhaust emissions from the hybrid bus were compared to a 1996 model year diesel-powered bus operated over the same driving cycles, and using the same inertia weight and road load as the hybrid bus. SwRI noted that the aftermarket CNG fuel system installed on the 2.0L VW engine did not function adequately; therefore, the exhaust emissions from the hybrid bus could have been much better if detailed optimization had been performed. In fact, NO{sub x} emissions were 25 to 30 percent higher than for the diesel bus. However, even with the non-optimum CNG fuel system, the exhaust emissions of NMHC and CO were significantly lower than observed for a comparable diesel bus. Although not directly measured, PM emissions from the hybrid bus were assumed to be essentially zero. Another significant finding was that the fuel consumption of the hybrid bus was 13 to 30 percent better than the diesel bus over the CBD-14 cycle, and 38 to 45 percent better than the diesel bus over the HDCC.

Fritz, S.G.; Bass, E.A.; Steiber, J.; Tobin, A.

1999-07-01

497

The Joint Distribution of the Virtual Waitingtime and the Residual Busy Period for the M/G/1 Queue.  

National Technical Information Service (NTIS)

In the M/G/1 queue, the joint distribution of the virtual waitingtime and the residual duration of the busy period at any time t, is given by a formula analogous to the one for the virtual waitingtime by itself. In the limit, as t approaches limit of infi...

M. F. Neuts

1967-01-01

498

Comparison of Tail Drop and Active Queue Management Performance for Bulk-Data and WebLike Internet Traffic  

Microsoft Academic Search

This paper compares the performance of Tail Drop and three different flavor s of the RED (RandomEarly Detection) queue management mechanism: RED with a standard pa- rameter setting, RED with an optimized parameter setting based on a model of RED with TCP flows, and finally a ver- sion of RED with a smoother drop function called \\

Christof Brandauer; Gianluca Iannaccone; Christophe Diot; Thomas Ziegler; Serge Fdida; Martin May

2001-01-01

499

The MAP\\/PH\\/1\\/N queue with flows of customers as a model for traffic control in telecommunication networks  

Microsoft Academic Search

A single-server queueing model with finite buffer and flows of customers is considered. Flow means a group of customers which should be sequentially processed in the system. In contrast to the standard batch arrival when a whole group of customers arrives into the system at one epoch, we assume that the customers of an accepted flow arrive one by one

Chesoong Kim; Sergey Dudin; Valentina I. Klimenok

2009-01-01

500

Gender and socioeconomic status as determinants of waiting time for inpatient surgery in a system with implicit queue management  

Microsoft Academic Search

Objective: In a system with implicit queue management, to examine gender and socioeconomic status as determinants of waiting time for inpatient surgery, after adjusting for other potential predictors. Methods: A cohort of 452 subjects was examined in outpatient clinics of a general hospital and referred to inpatient surgery. They were followed until scheduled hospital admission (n=396) or until the requested

Kjell E. Arnesen; Jan Erikssen; Knut Stavem

2002-01-01