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1

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

PubMed Central

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

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

2015-01-01

2

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

PubMed

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

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

2015-01-01

3

Radiation-Tolerant Dual Data Bus  

NASA Technical Reports Server (NTRS)

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

Kinstler, Gary A.

2007-01-01

4

Interface For Dual-Channel MIL-STD-1553 Data Bus  

NASA Technical Reports Server (NTRS)

Digital electronic subsystem made of commercially available programmable logic arrays and discrete logic devices serves as interface between microprocessor and dual-channel MIL-STD-1553 data bus. Subsystem consumes only 800 mW of power. Provides flexibility in that it is controllable via firmware. Includes only two reading-and-writing ports: one for status and control signals, other for transmission and reception of data.

Davies, Bryan L.; Heaps, Timothy L.

1992-01-01

5

Measuring in-cabin school bus tailpipe and crankcase PM2.5: a new dual tracer method.  

PubMed

Exposures of occupants in school buses to on-road vehicle emissions, including emissions from the bus itself, can be substantially greater than those in outdoor settings. A dual tracer method was developed and applied to two school buses in Seattle in 2005 to quantify in-cabin fine particulate matter (PM2.5) concentrations attributable to the buses' diesel engine tailpipe (DPMtp) and crankcase vent (PMck) emissions. The new method avoids the problem of differentiating bus emissions from chemically identical emissions of other vehicles by using a fuel-based organometallic iridium tracer for engine exhaust and by adding deuterated hexatriacontane to engine oil. Source testing results showed consistent PM:tracer ratios for the primary tracer for each type of emissions. Comparisons of the PM:tracer ratios indicated that there was a small amount of unburned lubricating oil emitted from the tailpipe; however, virtually no diesel fuel combustion products were found in the crankcase emissions. For the limited testing conducted here, although PMck emission rates (averages of 0.028 and 0.099 g/km for the two buses) were lower than those from the tailpipe (0.18 and 0.14 g/km), in-cabin PMck concentrations averaging 6.8 microg/m3 were higher than DPMtp (0.91 microg/m3 average). In-cabin DPMtp and PMck concentrations were significantly higher with bus windows closed (1.4 and 12 microg/m3, respectively) as compared with open (0.44 and 1.3 microg/m3, respectively). For comparison, average closed- and open-window in-cabin total PM2.5 concentrations were 26 and 12 microg/m3, respectively. Despite the relatively short in-cabin sampling times, very high sensitivities were achieved, with detection limits of 0.002 microg/m3 for DPMtp and 0.05 microg/m3 for PMck. PMID:21608489

Ireson, Robert G; Ondov, John M; Zielinska, Barbara; Weaver, Christopher S; Easter, Michael D; Lawson, Douglas R; Hesterberg, Thomas W; Davey, Mark E; Liu, L-J Sally

2011-05-01

6

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.

Shad Gilley

7

Fano-resonance-based Mach-Zehnder optical switch employing dual-bus coupled ring resonator as two-beam interferometer.  

PubMed

A kind of Mach-Zehnder optical switch with a dual-bus coupled ring resonator as a two-beam interferometer is proposed and investigated. The analysis based on the transfer matrix method shows that a sharp asymmetric Fano line shape can be generated in the transmission spectra of such a configuration, which can be used to significantly reduce the phase change required for switching. Meanwhile, it can also be found that complete extinctions can be achieved in both switching states if the structural parameters are carefully chosen and the phase bias is properly set. Through tuning the phase difference between the arms of the Mach-Zehnder interferometer, complete extinction can be easily kept within a large range of the ring-bus coupling ratios in the OFF state. By properly modulating the phase change in the ring waveguide, the shift of the resonant frequency and the asymmetry of the transmission spectra can be controlled to finally enable optical switching with a high extinction ratio, even complete extinction, in the ON state. The switching functionality is verified by the finite-difference time-domain simulation. PMID:19399151

Wang, Fan; Wang, Xiang; Zhou, Haifeng; Zhou, Qiang; Hao, Yinlei; Jiang, Xiaoqing; Wang, Minghua; Yang, Jianyi

2009-04-27

8

Network Queueing System  

NASA Technical Reports Server (NTRS)

Program directs traffic in UNIX-based network. NQS provides facilities for remote queueing, request routing, remote status, queue-access controls, batch-request resource-quota limits, and remote output return. Written in C.

Kingsbury, Brent

1988-01-01

9

The network queueing system  

NASA Technical Reports Server (NTRS)

Described is the implementation of a networked, UNIX based queueing system developed on contract for NASA. The system discussed supports both batch and device requests, and provides the facilities of remote queueing, request routing, remote status, queue access controls, batch request resource quota limits, and remote output return.

Kingsbury, Brent K.

1986-01-01

10

Research on algorithms of land-to-air missile launch control system based on CAN bus  

Microsoft Academic Search

In terms of the characteristics of CAN bus in the launch control system and the messages transmitted in network, a scheduling algorithm which is combined with Deadline Monotonic and Distributed Priority Queue scheduling algorithm is presented. The method is based on the CAN bus's rule of priority's arbitration bit by bit without destroy. Finally, the tracking simulation is carried out

Zhi-peng Jiang; Hua-ting Han; Gang Feng; Xin-sheng Dai

2011-01-01

11

Bus Training Handbook.  

ERIC Educational Resources Information Center

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

Dorny, Audrea; Cole, ChiKay

12

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

13

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

14

DATAC bus monitor  

NASA Technical Reports Server (NTRS)

The Digital Autonomous Terminal Access Communications (DATAC) bus is a multiple transmitter data bus developed to interconnect various aircraft systems. A typical DATAC bus installation for the NASA B-737 aircraft is shown. A bus monitor unit was developed for the DATAC data bus. The bus monitor unit consists of two systems: A Zilog Z8002 based S100 bus microcomputer system that connects to a DATAC terminal and receives data appearing on the bus, and an IMB PC-compatible computer used to display and interpret that data. Test results of the existing bus monitor have indicated areas for improvement. The most obvious improvement is to increase the speed of the data transfers between the S100 and the MS-DOS systems.

Novacki, Stanley M., III; Thomas, Robert J., Jr.

1988-01-01

15

Queueing for Healthcare  

Microsoft Academic Search

Patient queues are prevalent in healthcare and wait time is one measure of access to care. We illustrate Queueing Theory—an analytical tool that has provided many insights to service providers when designing new service systems and managing existing\\u000a ones. This established theory helps us to quantify the appropriate service capacity to meet the patient demand, balancing\\u000a system utilization and the

R. Kannapiran Palvannan; Kiok Liang Teow

16

Transit-bus maintenance  

SciTech Connect

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

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

1987-01-01

17

Instability of FIFO Queueing Networks  

Microsoft Academic Search

Consider a queueing network with customers arriving according to a rate-1 Poisson process. Each customer proceeds along the same prescribed route, waiting at the different queues until exiting from the system. The service times are assumed to be independent and exponentially distributed. Individual queues may be visited more than once by a customer, with the mean service time perhaps depending

Maury Bramson

1994-01-01

18

Queueing Theory February 8, 2010  

E-print Network

Queueing Theory February 8, 2010 Modeling a Queueing System Problem Statement: Consider a single: · Server status (state) · Number of customers in the queue (state) · A list of arrival times (state) · Time getting serviced is called a delay and denoted by Di. · Hence, the following relationship can be derived

Mukherjee, Amlan

19

Degree Worksheet -Accounting/Dual (The only difference b/w Accounting and Dual is the number of major electives required: 1 for Accounting, 6 for Dual)  

E-print Network

Financial Accounting ACC 450 Advanced Topics in Accounting BUS 320 Marketing Principles BUS 330 OperationsDegree Worksheet - Accounting/Dual (The only difference b/w Accounting and Dual is the number of major electives required: 1 for Accounting, 6 for Dual) Name: Date: Major: ACC Dual GENERAL EDUCATION

20

Hydrogen powered bus  

SciTech Connect

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

None

2011-04-07

21

Hydrogen powered bus  

ScienceCinema

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

None

2013-11-22

22

Factors influencing bus network design  

E-print Network

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

Loh, Zhen Xiang Kenneth

2014-01-01

23

AGRICULTURELN University bus stop  

E-print Network

AGRICULTURELN University bus stop University Graduation Day bus run (Runs from Shepherd Street.K. Ward R.M.C. Gunn St. John's Oval Veterinary Science Conference Round House J.D. Stewart J.D. Stewart Mc Library Teaching New Law Building Economics & Business Building Pharmacy Building Sydney University

Viglas, Anastasios

24

77 FR 6172 - Discretionary Bus and Bus Facilities Program and National Research Program Funds.  

Federal Register 2010, 2011, 2012, 2013, 2014

...Bus and Bus Facilities Program and National Research Program Funds...Bus and Bus Facilities Program and...5312 National Research Program Funds...Bus and Bus Facilities Program and...5312 National Research Program....

2012-02-07

25

Model Predictive Control for the Acquisition Queue and Related Queueing Networks  

E-print Network

]: Queueing theory General Terms Queueing Networks, Model Predictive Control 1. INTRODUCTION Queueing networksModel Predictive Control for the Acquisition Queue and Related Queueing Networks Johan S.H. van Predictive Control (MPC) is a well established method in control theory and engineering practice. It is often

Nazarathy, Yoni

26

Priority Queues for Computer Simulations  

NASA Technical Reports Server (NTRS)

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

Steinman, Jeffrey S. (Inventor)

1998-01-01

27

SCSI Communication Test Bus  

NASA Technical Reports Server (NTRS)

Small Computer System Interface (SCSI) communication test bus provides high-data-rate, standard interconnection enabling communication among International Business Machines (IBM) Personal System/2 Micro Channel, other devices connected to Micro Channel, test equipment, and host computer. Serves primarily as nonintrusive input/output attachment to PS/2 Micro Channel bus, providing rapid communication for debugger. Opens up possibility of using debugger in real-time applications.

Hua, Chanh V.; D'Ambrose, John J.; Jaworski, Richard C.; Halula, Elaine M.; Thornton, David N.; Heligman, Robert L.; Turner, Michael R.

1990-01-01

28

Message passing with queues and channels  

DOEpatents

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

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

2013-02-19

29

Hierarchical Packet Fair Queueing Algorithms  

Microsoft Academic Search

Hierarchical Packet Fair Queueing (H-PFQ) algorithms have the potential to simultaneously support guaranteed real-time service, rate-adaptive best-effort, and controlled link-sharing service. In this paper, we design practical H-PFQ algorithms by using one-level Packet Fair Queueing (PFQ) servers as basic building blocks, and develop techniques to analyze delay and fairness properties of the resulted H-PFQ servers. We demonstrate that, in order

Jon C. R. Bennett; Hui Zhang

1996-01-01

30

Bus supervision deployment strategies for improved bus service reliability  

E-print Network

Bus service reliability has always been a top concern for transit agencies and their customers. Unfortunately, there are several factors detrimental to reliable bus service. Outside influences such as weather, traffic, and ...

Pangilinan, Christopher Allan

2006-01-01

31

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

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

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

32

75 FR 52054 - Bus and Bus Facilities Discretionary Program Funds  

Federal Register 2010, 2011, 2012, 2013, 2014

...bus and bus-related projects for assistance to subrecipients that are public agencies, private companies engaged in public transportation, or private non-profit organizations. FOR FURTHER INFORMATION CONTACT: Successful and...

2010-08-24

33

77 FR 48592 - Bus and Bus Facilities Discretionary Program Funds  

Federal Register 2010, 2011, 2012, 2013, 2014

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

2012-08-14

34

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

E-print Network

Statistics for Social Sciences (85) [BUS,ECO,PSIR] (3-0)3 Ouz Solyali (2) BUS 222 Organization Theory (25) (3) Services Management (3-0)3 Ouz Solyali E BUS 472 Principles of Advertising (3-0)3 Carter Mandrik E BUS 476 and Management BUS 472 Principles of Advertising BUS 476 Retailing BUS 435 Computers and Networking BUS 466

Köprülü, Kahraman Güçlü

35

Multipurpose satellite bus (MPS)  

NASA Astrophysics Data System (ADS)

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

36

Multipurpose satellite bus (MPS)  

NASA Technical Reports Server (NTRS)

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

1991-01-01

37

Design a Tour Bus  

NSDL National Science Digital Library

This high school activity from the Florida Advanced Technological Education (FL-ATE) Center asks students to design and fabricate a tour bus for Florida-based Featherlite Coaches. On this page, visitors will find a link to a three-minute video about Featherlite and a fact sheet company overview to get students started in the context of the company and its particular needs in the tour bus. This is a great resource to introduce students to hands-on practices in design and manufacturing industries.

38

School Bus Fumes  

NSDL National Science Digital Library

A surprising fraction of the exhaust from school buses ends up back inside the bus. That's according to a study led by Julian Marshall, a Ph.D. student in the Energy and Resources Group at the University of California at Berkeley. He says the impact of a single bus is much greater on its passengers than on the passers-by. The research looks at how pollution children take up from the brief rides to school each morning. This Science Update looks at the research, which leads to the findings presented and offers links to other sources for further inquiry.

American Association for the Advancement of Science (; )

2005-05-16

39

QUEUEING THEORY A queue is a waiting line (like customers waiting at a supermarket checkout counter);  

E-print Network

QUEUEING THEORY A queue is a waiting line (like customers waiting at a supermarket checkout counter); queueing theory is the mathematical theory of waiting lines. More generally, queueing theory is concerned performance measures, such as average waiting time, server utilization, throughput, probability of buffer

Cooper, Robert B.

40

The Temporal Mechanics of Queue Size Estimation in Random Early Detection (RED) Queues  

Microsoft Academic Search

Random Early Detection (RED) queues are becom- ing ubiquitous as they offer higher throughput, lower latency and more fairness than FIFO drop tail queues with a relatively low implementation cost. By increasing the probability of dropping a packet as the queue size increases, RED queues attempt to detect imminent con- gestion and avoid it by informing flows about it (by

Sharad Agarwal; Shawn M. Ledbetter

41

Mux\\/Demux Queues, FIFO Queues, and Their Construction by Fiber Memories  

Microsoft Academic Search

This paper considers a packet multiplexer (resp. de- multiplexer) in the form of a queue with a single time-multiplexed input (resp. output) line, which is called a multiplexing queue (resp. demultiplexing queue). This queue is abstractly formulated in a way that allows recursive construction via 2-stage interconnection. The theoretic underpinning of this recursive construction is the preser- vation of two

Shuo-Yen Robert Li; Xuesong Jonathan Tan

2011-01-01

42

Task allocation policies for State Dependent queues  

E-print Network

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

Siew, Christine Chiu Hsia

2011-01-01

43

Queueing Models with Multiple Waiting Lines  

Microsoft Academic Search

This paper discusses analytic solution methods for queueing models with multiple wait- ing lines. The methods are briefly illustrated, using key models like the 2 × 2 switch, the shortest queue and the cyclic polling system.

Ivo J. B. F. Adan; Onno J. Boxma; Jacques Resing

2001-01-01

44

Queues and Simulations for Secondary School Students  

ERIC Educational Resources Information Center

A self-teaching module on queues, dealing with the use of random numbers in the simulation of realistic queueing or waiting-line situations, is described. Both mathematical content and teaching methods are considered. (MNS)

Copes, Wayne; And Others

1986-01-01

45

Queueing Models with Multiple Waiting Lines  

Microsoft Academic Search

This paper discusses analytic solution methods for queueing models with multiple waiting lines. The methods are briefly illustrated, using key models like the 2×2 switch, the shortest queue and the cyclic polling system.

I. J. B. F. Adan; O. J. Boxma; J. A. C. Resing

2001-01-01

46

Bus-Programmable Slave Card  

NASA Technical Reports Server (NTRS)

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

Hall, William A.

1990-01-01

47

"Ruggedized" Microcomputer Bus  

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

48

Augmented Thermal Bus  

NASA Technical Reports Server (NTRS)

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

Schrage, Dean S. (Inventor)

1996-01-01

49

Queueing Models of Call Centers: An Introduction  

Microsoft Academic Search

This is a survey of some academic research on telephone call centers. The surveyed research has its origin in, or is related to, queueing theory. Indeed, the “queueing-view” of call centers is both natural and useful. Accordingly, queueing models have served as prevalent standard support tools for call center management. However, the modern call center is a complex socio-technical system.

Ger Koole; Avishai Mandelbaum

2002-01-01

50

On the Efficient Implementation of Fair Queueing  

Microsoft Academic Search

The performance of packet switched data networks is greatly influenced by the queue service disci- pline in routers and switches. In particular, the Fair Queueing discipline (1) has several advantages over the traditional first-come-first-served discipline. This paper studies data structures and algorithms for the effi- cient implementation of Fair Queueing. We present a novel performance evaluation methodology and use it

Srinivasan Keshav

1991-01-01

51

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

52

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

53

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

54

Dynamics of priority-queue networks  

NASA Astrophysics Data System (ADS)

Recent application of priority queue models for human dynamics opened a way to study the human behavior under quantitative framework. Given the evident active engagement in social networking of individuals, dynamics of priority queues forming networks needs to be understood. Along this line, here we study the dynamics of priority-queue networks by generalizing the binary interacting priority queue model of Oliveira and Vazquez (OV). We found that the OV model with AND-type protocol for interacting tasks is in general not scalable for the queue networks with more than two queues, because the dynamics for interacting tasks become quickly frozen due to the priority conflicts. We then consider 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, finding that its distribution exhibits power-law tail in all cases considered, yet with exponents dependent on the network topology. We also show that when the tasks in the queue network are executed synchronously, priority conflicts affect the waiting time dynamics strongly, resulting in a different power law.

Min, Byungjoon; Goh, Kwang-Il; Kim, In-Mook

2009-03-01

55

Transient approximations in queueing networks  

E-print Network

Jackson network. The approximations were tested on networks ranging in size from 4 to 61 nodes, with various initial conditions and loading. Both stationary and nonstationary systems were tested. The closure approximations performed well for the Jackson... approximation simulations. The closure simulation and Monte Carlo simulations were compared for networks of up to 32 nodes, containing up to 80 queues. The network simulations were also tested with various parameters. The results of the closure approximation...

Andrewartha, John Michael

1989-01-01

56

Hierarchical packet fair queueing algorithms  

Microsoft Academic Search

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

Jon C. R. Bennett; Hui Zhang

1997-01-01

57

Hybrid Electric Transit Bus  

NASA Technical Reports Server (NTRS)

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

Viterna, Larry A.

1997-01-01

58

High-Speed Ring Bus  

NASA Technical Reports Server (NTRS)

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

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

2010-01-01

59

TCP performance under aggregate fair queueing  

Microsoft Academic Search

In this paper, we studied TCP performance under aggregate fair queueing (FQ). We first showed the livelock problem of FQ under the DropFront scheme, and proposed a simple solution to the problem. Then, to improve the fairness of aggregate FQ, we proposed a new active buffer-management scheme called ALQD+ (approximated longest queue drop), which is fairer than ALQD. Based on

Wei Sun; Kang G. Shin

2004-01-01

60

CS271: Data Structures Queue Worksheet  

E-print Network

waiting queue that feeds all cashiers vs having a separate waiting queue (separate line) for each cashier in discrete time event simulators. We will build an application to model the customer line at Wendys of subsequent lines). The arrival time is a time stamp in seconds that indicates what time the customer arrives

Kretchmar, R. Matthew

61

Reducing queues: demand and capacity variations  

Microsoft Academic Search

Purpose – The aim of this paper is to investigate how waiting lists or queues could be reduced without adding more resources; and to describe what factors sustain reduced waiting-times. Design\\/methodology\\/approach – Cases were selected according to successful and sustained queue reduction. The approach in this study is action research. Findings – Accessibility improved as out-patient waiting lists for two

Henrik Eriksson; Ing-Marie Bergbrant; Ingela Berrum; Boel Mörck

2011-01-01

62

Bus travel safety - A travel chain perspective  

Microsoft Academic Search

The injury risk for bus passengers is low compared to car users. However, bus passengers also run the risk of sustaining injuries as vulnerable road users: as pedestrians or cyclists to and from the bus stop. Among vulnerable road users, seniors are a particularly important group. Hitherto, injury data have mainly been based on police-reported accidents. These accidents reveal bus

Monica Berntman; Anders Wretstrand; Bengt Holmberg

2010-01-01

63

Bus Serialization for Reducing Power Consumption  

Microsoft Academic Search

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

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

2006-01-01

64

Analysis and simulation of a fair queueing algorithm  

Microsoft Academic Search

We discuss gateway queueing algorithms and their role in controlling congestion in datagram networks. A fair queueing algorithm, based on an earlier suggestion by Nagle, is proposed. Analysis and simulations are used to compare this algorithm to other congestion control schemes. We find that fair queueing provides several important advantages over the usual first-come-first-serve queueing algorithm: fair allocation of bandwidth,

Alan J. Demers; Srinivasan Keshav; Scott J. Shenker

1989-01-01

65

Managing Your District's Bus Contractor.  

ERIC Educational Resources Information Center

Describes the essential elements of a student bus transportation contract with a private transportation service company such as reporting requirements, problem-solving procedures, and performance penalties and incentives. (PKP)

Walsh, Mark A.

2002-01-01

66

Reducing transit bus emissions: Alternative fuels or traffic operations?  

NASA Astrophysics Data System (ADS)

In this study, we simulated the operations and greenhouse gas (GHG) emissions of transit buses along a busy corridor and quantified the effects of two different fuels (conventional diesel and compressed natural gas) as well as a set of driving conditions on emissions. Results indicate that compressed natural gas (CNG) reduces GHG emissions by 8-12% compared to conventional diesel, this reduction could increase to 16% with high levels of traffic congestion. However, the benefits of switching from conventional diesel to CNG are less apparent when the road network is uncongested. We also investigated the effects of bus operations on emissions by applying several strategies such as transit signal priority (TSP), queue jumper lanes, and relocation of bus stops. Results show that in congested conditions, TSP alone can reduce GHG emissions by 14% and when combined with improved technology; a reduction of 23% is achieved. The reduction benefits are even more apparent when other transit operational improvements are combined with TSP. Finally a sensitivity analysis was performed to investigate the effect of operational improvements on emissions under varying levels of network congestion. We observe that under “extreme congestion”, the benefits of TSP decrease.

Alam, Ahsan; Hatzopoulou, Marianne

2014-06-01

67

Queues and oscillators: supersymmetric partners?  

NASA Astrophysics Data System (ADS)

Using the supersymmetric relation between continuous time Markov processes and quantum models, it is shown that the celebrated model for queues with infinitely many servers is nothing else than a quantum harmonic oscillator in disguise. In view of the multitude of Markov models that can be considered as a quantum theory, the converse has also been investigated: it turns out that the transformation t arrow imath t is enough to prove the equivalence. The transformation from Markov process to quantum model is obtained by relatively simple operations. The inverse transformation requires, as is wellknown in SUSY, the knowledge of a node-less eigenstate of the quantum model.

Lemmens, L. F.

1997-03-01

68

Forecast analysis of optical waveguide bus performance  

NASA Technical Reports Server (NTRS)

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

Ledesma, R.; Rourke, M. D.

1979-01-01

69

Preventing messaging queue deadlocks in a DMA environment  

DOEpatents

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

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

2014-01-14

70

Aids to School Bus Design  

NASA Technical Reports Server (NTRS)

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

71

QUEUEING WITH FUTURE INFORMATION By Joel Spencer  

E-print Network

incoming jobs at rate (1 - p, 1), and the decision maker is allowed to redirect away jobs up to a rate . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Keywords and phrases: future information, forecast, queueing theory, resource pooling, random walk

Sudan, Madhu

72

Large scale queueing systems : asymptotics and insights  

E-print Network

Parallel server queues are a family of stochastic models useful in a variety of applications, including service systems and telecommunication networks. A particular application that has received considerable attention in ...

Goldberg, David Alan, Ph. D. Massachusetts Institute of Technology

2011-01-01

73

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

74

Some Questions to Ask about Your School Bus Program.  

ERIC Educational Resources Information Center

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

Balousek, Marvin

1980-01-01

75

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

E-print Network

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

Wise, Evan Dale

2013-01-01

76

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

E-print Network

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

Billey, Sara

77

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

78

The NASA bus communications listening device software  

NASA Technical Reports Server (NTRS)

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

Allen, M. A.

1979-01-01

79

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

80

Low-inductance bus lines  

NASA Technical Reports Server (NTRS)

Laminated bus strips and bifilar litz cable connectors for high-power rectifiers, thrisistors, and transistors provide low inductance and eliminate electromagnetic interference in high-power circuits. These techniques offer significant cost advantages because of ease of assembly and consistent high quality of product. Effectiveness makes general usage in static power conversion likely.

Kernick, A.

1977-01-01

81

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

NASA Technical Reports Server (NTRS)

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

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

1998-01-01

82

On the Role of Queue Length Information in Network Control  

E-print Network

We study the role played by queue length information in the operation of flow control and server allocation policies. We first consider a simple model of a single server queue with congestion-based flow control. The input ...

Jagannathan, Krishna Prasanna

83

Queueing Behavior over a Gilbert-Elliott Packet Erasure Channel  

E-print Network

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

Cai, Yi

2012-02-14

84

Electrical system architecture having high voltage bus  

DOEpatents

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

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

2011-03-22

85

Cycle time variability for a network under two queueing disciplines  

E-print Network

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

Vasquez Pariente, Marta Irene

1996-01-01

86

Analysis of Active Queue Management Jae Chung and Mark Claypool  

E-print Network

Management (AQM) is intended to achieve high link utilization with a low queuing delay. Recent stud- ies showAnalysis of Active Queue Management Jae Chung and Mark Claypool Computer Science Department traffic on the load and queue behavior of con- gested routers. Through queue law analysis and simulation

Claypool, Mark

87

Analysis of Active Queue Management Jae Chung and Mark Claypool  

E-print Network

Management (AQM) is intended to achieve high link utilization with a low queuing delay. Recent stud­ ies showAnalysis of Active Queue Management Jae Chung and Mark Claypool Computer Science Department traffic on the load and queue behavior of con­ gested routers. Through queue law analysis and simulation

Claypool, Mark

88

Simulation of waiting line systems with queue length dependent parameters  

Microsoft Academic Search

A queueing system is simulated in which the arrival and service rates are functions of the number of customers in the system. This type of system has been suggested as being more representative of real queueing situations than is the usual “simple” queue with constant arrival and service rates. A modification of the “time of next event” simulation method is

Irwin Greenberg; Susan Heimrath

1971-01-01

89

Quantifying Fairness in Queueing Systems: Principles, Approaches and Applicability  

E-print Network

1 Quantifying Fairness in Queueing Systems: Principles, Approaches and Applicability ABSTRACT In this paper we discuss fairness in queues, view it in the perspective of social justice at large and survey the recently published research work and publications dealing with the issue of measuring fairness of queues

Levy, Hanoch

90

LIMIT DISTRIBUTIONS FOR QUEUES AND RANDOM ROOTED TREES  

Microsoft Academic Search

In this paper several limit theorems are proved for the fluctuations of the queue size during the initial busy period of a queuing process with one server. These theorems are used to find the solutions of various problems connected with the heights and widths of random rooted trees. Single-server queues, queue size, random trees, There is an intrinsic relationship between

LAJOS TAK

91

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

92

PinBus Interface Design  

SciTech Connect

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

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

2009-12-30

93

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

Federal Register 2010, 2011, 2012, 2013, 2014

...bus and bus-related projects for assistance to subrecipients that are public agencies, private companies engaged in public transportation, or private non-profit organizations. Additionally, the SGR Initiative makes funds available...

2011-11-07

94

76 FR 68813 - FY 2011 Discretionary Livability Funding Opportunity; Section 5309 Bus and Bus Facilities...  

Federal Register 2010, 2011, 2012, 2013, 2014

...providers to finance capital projects to replace, rehabilitate...of bus and bus- related projects for assistance to subrecipients...capital investments (``New Starts'' and ``Small Starts'' projects) in the evaluation of...

2011-11-07

95

State space transformations in queueing network modeling  

Microsoft Academic Search

An important problem in queueing network modeling is that of characterizing and analyzing relationships among alternative models of a single system. The problem is approached by developing the concept of a state space transformation, which is a mechanism for expressing the way one model can be mapped into another. After discussing state space transformations in general terms, some important transformations

Jeffrey P. Buzen; Subhash C. Agrawal

1983-01-01

96

CS271: Data Structures Queue Worksheet  

E-print Network

in discrete time event simulators. We will build an application to model the customer line at Wendys of subsequent lines). The arrival time is a time stamp in seconds that indicates what time the customer arrives at the appropriate clock times and send them to a cashier. You will need to implement a waiting queue as well

Kretchmar, R. Matthew

97

Balanced job bound analysis of queueing networks  

Microsoft Academic Search

Applications of queueing network models to computer system performance prediction typically involve the computation of exact equilibrium solutions. This procedure can be quite expensive. In actual modeling studies, many alternative systems must be considered and a model of each developed. The expense of computing the exact solutions of these models may not be warranted by the accuracy required at the

John Zahorjan; Kenneth C. Sevcik; Derek L. Eager; Bruce Galler

1982-01-01

98

Balanced job bound analysis of queueing networks  

Microsoft Academic Search

Applications of queueing network models to computer system performance prediction typically involve the computation of their equilibrium solution. When numerous alternative systems are to be examined and the numbers of devices and customers are large, however, the expense of computing the exact solutions may not be warranted by the accuracy required. In such situations, it is desirable to be able

John Zahorjan; Kenneth C. Sevcik; Derek L. Eager; Bruce Galler

1981-01-01

99

Simulating a stack by queues Burton Rosenberg  

E-print Network

A finite automata is a directed graph with labeled arrows. A single marker is moved from node to node and Computer Science Abstract We explore the complexity relationships between finite automata en­ dowed with various data structures as auxiliary stores. It is shown that a queue automata, a finite state machine

Rosenberg, Burton

100

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

2013-11-01

101

Hidden Savings in your Bus Budget  

ERIC Educational Resources Information Center

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

Newby, Ruth

2005-01-01

102

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

103

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.

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

1991-01-01

104

Automatic Verification of Multi-queue Discrete Timed Automata  

Microsoft Academic Search

We propose a new infinite-state model, called the Multi-queue Dis- crete Timed Automaton MQDTA, which extends Timed Automata with queues, but only has integer-valued clocks. Due to careful restrictions on queue usage, the binary reachability (the set of all pairs of configurations ( of an MQDTA such that can reach through zero or more transitions) is effectively semilin- ear. We

Pierluigi San Pietro; Zhe Dang

2003-01-01

105

Instability of FIFO Queueing Networks with Quick Service Times  

Microsoft Academic Search

A class of open first-in, first-out queueing networks is examined. Customers arrive according to a rate-1 Poisson process and wait at queues along their prescribed routes for exponential holding times, after which they exit from the system. Such a network can be chosen so that the sum of the mean service times at each queue is as small as desired.

Maury Bramson

1994-01-01

106

Analog bus driver and multiplexer  

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

107

Hybrid propulsion technologies for urban bus transit. Final report, January-June 1983  

Microsoft Academic Search

This report presents overview information on hybrid propulsion technologies (also called dual propulsion) in order to increase the transit community's awareness and understanding of bus-propulsion designs that offer extended-use capability for trolley-emergency, short-range, and back-up propulsion for trolley buses or offer some overall energy or fuel savings. Technical material is provided to a greater extent on systems that are novel

R. Gunderson; H. Wychorski

1984-01-01

108

On the steady-state queue size distribution of the discrete-timeGeo\\/G\\/1 queue with repeated customers  

Microsoft Academic Search

In this paper, we study the steady-state queue size distribution of the discrete-timeGeo\\/G\\/1 retrial queue. We derive analytic formulas for the probability generating function of the number of customers in the system in steady-state. It is shown that the stochastic decomposition law holds for theGeo\\/G\\/1 retrial queue. Recursive formulas for the steady-state probabilities are developed. Computations based on these recursive

Tao Yang; Hui Li

1995-01-01

109

Cost performance satellite design using queueing theory  

NASA Technical Reports Server (NTRS)

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

Hein, G. F.

1975-01-01

110

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

111

Analysis and simulation of a city bus route  

NASA Astrophysics Data System (ADS)

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

Kar, Leow Soo

2014-12-01

112

QUEUES IN CINEMAS Mehri Houda et D.Taoufik  

E-print Network

1 QUEUES IN CINEMAS Mehri Houda et D.Taoufik Laboratoire GIAD, FSEGS, BP 1088, Route de l conférencier : Mehri Houda GSM : 99228286 Abstract: Queues in Tunisia's cinemas are common phenomena. Whenever queuing at cinemas to book cinema tickets. Not only all cinemas have their operating cost, they do have

Paris-Sud XI, Université de

113

A queueing system with returning customers and waiting line  

Microsoft Academic Search

We consider a queueing system where a customer who finds all channels busy must decide either to join the queue or to retry after an exponentially distributed time. The performance of the system can be approximated by using the RTA approximation introduced by Wolff and Greenberg. We present numerical results demonstrating the performance of the approximation for various representative cases.

J. R. Artalejo

1995-01-01

114

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

E-print Network

a Queueing System Problem Statement: Consider a single server queueing system which consists of a server) Representation The System State consists of the following: · Server status (state) · Number of customers relationship can be derived: Ci = ti + Di + Si (1) where Ci is the departure time point of the i - th customer

Mukherjee, Amlan

115

OR/MS Today -June 2006 Queueing Theory  

E-print Network

of our economic product. This rising cost can be attributed in part to aging populations and the expenseOR/MS Today - June 2006 Queueing Theory Patient Flow The new queueing theory for healthcare. By Randolph W. Hall From birth to death, we are all part of the healthcare system. We rely on both public

Valero-Cuevas, Francisco

116

Queueing systems subject to random server failures: an approximation  

E-print Network

In the traditional study of queueing theory, a typical ics. assumption is that the server is not subject to failures. This assumption, however, is not realistic for modeling many queueing systems in practice. Since the late 1950's, there has been...

Matis, Timothy

1998-01-01

117

A Resource Allocation Queueing Fairness Measure: Properties and Bounds  

E-print Network

A Resource Allocation Queueing Fairness Measure: Properties and Bounds Benjamin Avi-Itzhak RUTCOR-Aviv University, Tel-Aviv, Israel davidraz@post.tau.ac.il May 25, 2005 Abstract Fairness is an inherent studies show that fairness is highly important to queueing customers in actual situations. Despite

Levy, Hanoch

118

Queueing Network Approximations for Mass Dispensing and Vaccination Clinics  

Microsoft Academic Search

ABSTRACT To respond to bioterrorism events or to curb outbreaks of contagious diseases, county health departments must set up and operate clinics to dispense medications or vaccines. Planning these clinics in advance of such an event requires determining clinic capacity and estimating the queueing that may occur in such facilities. We construct a queueing network model for mass dispensing and

Ali Pilehvar; Jeffrey W. Herrmann

119

Loss correlation for queues with bursty input streams  

Microsoft Academic Search

The authors evaluate and characterize the correlation between packet losses for two queuing systems in discrete time that are motivated by broadband ISDN (BISDN) applications. The first, a two-class discrete-time queuing system, approximates the output queue of an asynchronous transfer mode (ATM) switch. The queue serves periodic foreground traffic and random background traffic. The background traffic is modeled as independently

Henning Schulzrinne; James F. Kurose; Donald F. Towsley

1992-01-01

120

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

E-print Network

as n , by virtue of the law of large numbers. Consequently, for any fixed traffic intensity Queueing Systems manuscript No. (will be inserted by the editor) Heavy-Traffic Limits for Nearly Deterministic Queues: Stationary Distributions Karl Sigman · Ward Whitt Received: date / Accepted: date Abstract

Whitt, Ward

121

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

122

Queue selection and switching by false clown anemonefish, Amphiprion ocellaris  

Microsoft Academic Search

Social groups of false clown anemonefish have been described as queues because, following settlement, fish acquire social rank passively by outliving more dominant groupmates. Within each queue, reproduction is restricted to the dominant pair. Therefore, individuals should adopt tactics that maximize their likelihood of attaining social dominance. Field observations indicated that, independent of an anemone's size, postlarval false clowns are

JEREMY MITCHELL

2005-01-01

123

CALIBRATION PARTS SHEET 1 The Spacecraft Bus  

E-print Network

facing side, to control thermal radiation. The bus is connected mechanically to the Propulsion Module Module carries a large mass of propellant mainly to power its rocket engine for deceleration into orbit

124

16 Load Data Cleansing and Bus Load  

E-print Network

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

Wang, Ke

125

Bus Route Map Todai-nishi  

E-print Network

getting on, get on the bus at the back door and accurately press the card to the card reader. You don't have to take a numbered ticket. When getting off the bus, press the card to the reader of the fare box door (if you got on from the start, put in only the fare). How to Use IC Card (PASMO/Suica) When

Yamamoto, Hirosuke

126

MARBLE: an asynchronous on-chip macrocell bus  

Microsoft Academic Search

This paper presents MARBLE, the Manchester Asynchronous Bus for Low Energy, a two channel asynchronous micropipeline-style VLSI macrocell bus. In addition to basic bus functions, MARBLE supports bus-bridging and test access, demonstrating that all the functions of a high speed macrocell bus can be implemented efficiently in a practical, fully asynchronous design style.MARBLE is used in the AMULET3i asynchronous Microprocessor

W. J Bainbridge; S. B Furber

2000-01-01

127

TMS communications software. Volume 2: Bus interface unit  

NASA Technical Reports Server (NTRS)

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

Gregor, P. J.

1979-01-01

128

Maximum Queue Length of a Fluid Model with a Gaussian Input  

E-print Network

queueing model, which is a queueing model with an input of a continuous Gaussian process, has received much attention. In this dissertation, a Gaussian queueing model is discussed and the maximum queue length over a time interval [0, t] is analyzed. Under...

Jin, Yasong

2007-12-11

129

Efficient Simulation of a Tandem Queue with Server Slow-down  

E-print Network

Efficient Simulation of a Tandem Queue with Server Slow-down D.I. Miretskiy , W.R.W. Scheinhardt widespread appli- cation in various domains. One such a variant is the tandem queue with server slow-down, in which the server of the upstream queue reduces its service speed as soon as the down- stream queue

Al Hanbali, Ahmad

130

Effect of exponential averaging on the variability of a RED queue  

Microsoft Academic Search

The paper analyzes how using a longer memory of the past queue occupancy in computing the average queue occupancy affects the stability and variability of a RED queue. Extensive simulation studies with both persistent and Web TCP sources are used to study the variance of the RED queue as a function of the memory of the averaging process. Our results

Archan MISRA; Teunis Ott; John Baras

2001-01-01

131

Systems evaluation of thermal bus concepts  

NASA Technical Reports Server (NTRS)

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

Stalmach, D. D.

1982-01-01

132

Queueing phase transition: theory of translation  

PubMed Central

We study the current of particles on a lattice, where to each site a different hopping probability has been associated and the particles can move only in one direction. We show that the queueing of the particles behind a slow site can lead to a first-order phase transition, and derive analytical expressions for the configuration of slow sites for this to happen. We apply this stochastic model to describe the translation of mRNAs. We show that the first-order phase transition, uncovered in this work, is the process responsible for the classification of the proteins having different biological functions. PMID:19519001

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

2013-01-01

133

Queueing phase transition: theory of translation.  

PubMed

We study the current of particles on a lattice, where to each site a different hopping probability has been associated and the particles can move only in one direction. We show that the queueing of the particles behind a slow site can lead to a first-order phase transition, and derive analytical expressions for the configuration of slow sites for this to happen. We apply this stochastic model to describe the translation of mRNAs. We show that the first-order phase transition, uncovered in this work, is the process responsible for the classification of the proteins having different biological functions. PMID:19519001

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

2009-05-15

134

BusRapidTransitandLandUse Bus Transit and Land Use  

E-print Network

BusRapidTransitandLandUse 21 Bus Transit and Land Use: Illuminating the Interaction Andy Johnson transit in urban areas has proven to be a difficult task indeed. Recent research on the transportation­land use connection has suggested that transit use can be increased through transit-friendly land use

Levinson, David M.

135

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

E-print Network

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

Kuenzer, Karen Elizabeth

1993-01-01

136

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

SciTech Connect

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

Not Available

2010-05-01

137

Martingale methods for analysing single{server queues M. Roughan y and C.E.M. Pearce z  

E-print Network

, and an example of a queue{length{threshold overload{control system. keywords: M=G=1 queue, martingale, queueing, phase, overload control 1 Introduction The M=G=1 queue is one of the fundamental models of queueing of this work was done while M. Roughan was a PhD student at the University of Adelaide, supported

Roughan, Matthew

138

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

E-print Network

and enable the SPI interrupt. A high pulse on the PAI line indicates that the turret is present and waiting /F7 /CS_COM MOSI MISO CLK PAI SLAVE #2 All slave turrets are in IDLE state and are waiting to configure the PAI and MISO pins as output. If two or more turrets set those two lines as output, a bus

Napp, Nils

139

Queues for Simulation From cars lined up at a tollbooth to print jobs waiting for a printer, queues abound in every day  

E-print Network

Queues for Simulation From cars lined up at a tollbooth to print jobs waiting for a printer, queues abound in every day life. The next example uses a queue to model and simulate a customer waiting line a waiting line at the ATM machine for a period of one hour. Make the following assumptions: With equal

Simonson, Shai

140

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

PubMed

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

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

2014-05-01

141

An accounting system for small bus companies  

E-print Network

AH ACCOUNTING SYSTEM FOR SMALL BUS CCMPAEIES A Thesis Hovrard Marion Gates May 1944 Approval as to style and oontent recommendedi Head o e epar1men o ocoun ng t st os AB ACCCQHTXSO SYBTBL PCS IALL BUS C(LPAHXKS A ThoaiS Horned Bu 9. oa Catos... @atishios Rcmord Laricu Qotoe Tho urger ia grotoful 4o Profooaors T. 8, Lola' and R. D. Dur& for %holm helpful ou~oot1oao hx tho proportion of this %hosea. X Isbn odgo@ion ~ I w y ~ e e ~ s ~ ~ ~ ~ ~ ~ ~ XX Classification ac@ Che& of Accounts...

Gates, Howard Marion

1944-01-01

142

Understanding bus travel time variation using AVL data  

E-print Network

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

Gerstle, David G

2012-01-01

143

Motivations and barriers to riders' acceptance of bus transit  

SciTech Connect

To determine why consumers use or do not use bus transit systems, a representative sample of middle-class Boulder, Colo., women shoppers who had access to the city's bus system was surveyed. Some 213 usable responses were obtained out of 397 questionnaires mailed. Survey results showed that consumers did not ride the bus to go shopping because it was too complicated to use. Bus routes, bus identification, and bus stops were perceived to be difficult to understand. Those consumers who frequently used the bus system did so because it was more compatible with ecological concerns than using a car was. The extent to which these findings can be generalized with previous studies on the motivations and barriers to riders' acceptance of bus transit is discussed. (5 references, 6 tables)

Schwartz, M.B.

1980-01-01

144

The crew activity planning system bus interface unit  

NASA Technical Reports Server (NTRS)

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

Allen, M. A.

1979-01-01

145

Analysis of Shared Memory Priority Queues with Two Discard Levels  

E-print Network

1 Analysis of Shared Memory Priority Queues with Two Discard Levels Shlomi Bergida and Yuval challenge. We present a simple analysis of a multipriority multi discard level system controlled by a buffer

Shavitt, Yuval

146

Optimal Routing in General Finite Multi-Server Queueing Networks  

PubMed Central

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

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

2014-01-01

147

A Report on Stochastic Fairness Queueing (SFQ) Experiments  

NASA Technical Reports Server (NTRS)

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

Denny, Barbara A.

1993-01-01

148

Opportunistic Channel Scheduling for Ad Hoc Networks with Queue Stability  

NASA Astrophysics Data System (ADS)

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

Dong, Lei; Wang, Yongchao

2015-03-01

149

On the Queue Tail Asymptotics for General Multifractal Traffic  

E-print Network

On the Queue Tail Asymptotics for General Multifractal Traffic S´andor Moln´ar1 , Trang Dinh Dang1 3889, Fax: (361) 463 3107 {molnar, trang, maricza}@ttt-atm.ttt.bme.hu Abstract. The tail asymptotics

Molnár, Sándor

150

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

151

CAN Bus Network Design Based on Bluetooth Technology  

Microsoft Academic Search

The integration between Bluetooth technology and the field bus is an important item in the industry field application of the wireless communication. By the analysis of Bluetooth technology and the field bus network topology architecture, we put over the interconnect topology architecture based on Bluetooth wireless sensor network and CAN bus, also finish the system hardware design and software development

Xiaohong Ren; Chenghua Fu; Tianwen Wang; Shuxiang Jia

2010-01-01

152

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

NASA Technical Reports Server (NTRS)

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

Gerber, C. R.

1972-01-01

153

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

Microsoft Academic Search

In order to make photoelectric encoder usable in a spaceflight camera which adopts CAN bus as the communication method, CAN bus interface of the photoelectric encoder is designed in this paper. CAN bus interface hardware circuit of photoelectric encoder consists of CAN bus controller SJA 1000, CAN bus transceiver TJA1050 and singlechip. CAN bus interface controlling software program is completed

Ying Sun; Qiu-Hua Wan; Rong-Hong She; Chang-Hai Zhao; Yong Jiang

2009-01-01

154

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

E-print Network

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

Fukai, Tomoki

155

Mission Services Evolution Center Message Bus  

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

156

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...

157

Energy DataBus (Fact Sheet)  

SciTech Connect

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

Not Available

2013-07-01

158

x Objects and Services x Bus Arbitration  

E-print Network

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

Kozak, Victor R.

159

UW Employee Bus Pass Online Ordering Instructions  

E-print Network

. Review payment information, click "Pay Now" and follow the instructions for a credit card payment or pre week, email tdm@fpm.wisc.edu with the subject line "bus pass lost in mail". We will work to resolve. a. Acquire a Wiscard. Wiscards are free and available at Union South. For more information see http

Wisconsin at Madison, University of

160

School Bus Accidents: Reducing Incidents and Injuries  

ERIC Educational Resources Information Center

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

Mahoney, Daniel

2009-01-01

161

Consumer electronics bus, a robust communications system  

Microsoft Academic Search

The Electronic Industries Association (EIA) is completing its consumer electronics bus (CEBus) standard to establish a common communication network through which any consumer electronics devices may exchange control information and data. The authors present some of the unique problems and solutions encountered by the committee in designing the CEBus protocol

B. Markwalter; C. Russell

1988-01-01

162

Active Tapes: Bus-Based Sensor Networks  

Microsoft Academic Search

In this work we present Active Tapes, a bus orga- nization for sensor networks. We construct simple cost models to compare active tapes against more traditional wireless sensor networks. Our models show that density, lifetime, and power con- sumption play significant roles in determining overall depl oyment and maintenance cost. We then characterize regimes where tapes are always cost effective,

Andrew Tjang; Michael Pagliorola; Hiral Patel; Xiaoyan Li; Richard P. Martin

2004-01-01

163

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

164

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

NASA Astrophysics Data System (ADS)

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

Zhu, H. B.

2010-08-01

165

A series of small scientific satellite with flexible standard bus  

NASA Astrophysics Data System (ADS)

Japan Aerospace Exploration Agency has a plan to develop the small satellite standard bus for various scientific missions and disaster monitoring missions. The satellite bus is a class of 250-400 kg mass with three-axis control capability of 0.02? accuracy. The science missions include X-ray astronomy missions, planetary telescope missions, and magnetosphere atmosphere missions. In order to adapt the wide range of mission requirements, the satellite bus has to be provided with flexibility. The concepts of modularization, reusability, and product line are applied to the standard bus system. This paper describes the characteristics of the small satellite standard bus which will be firstly launched in 2011.

Saito, Hirobumi; Sawai, Syujiro; Sakai, Shin-ichiro; Fukuda, Seisuke; Kitade, Kenji

2009-11-01

166

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

167

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

168

A Retrial Queue with a Constant Retrial Rate, Server Downs and Impatient Customers  

Microsoft Academic Search

In this paper, we consider a retrial queueing system consisting of a waiting line of infinite capacity in front of a single server subject to breakdowns. A customer upon arrival may join the queue (waiting line) or go to the retrial orbit (another queue) to retry for service after a random time. Only the customer at the head of the

Hui Li; Yiqiang Q. Zhao

2005-01-01

169

AN EGRESS QUEUE MANAGER FOR 8 X 100 MBPS AND 1 X 1GBPS  

E-print Network

AN EGRESS QUEUE MANAGER FOR 8 X 100 MBPS AND 1 X 1GBPS ETHERNET SWITCH PORT CONTROLLERS by BARRY: Barry Gordon Moss Degree: Master of Engineering Title of thesis: An Egress Queue Manager for 8 x 100;iii Abstract The project consists of the design of an Egress Queue Manager (EQM), a major functional

Trajkovic, Ljiljana

170

Equivalent models for queueing analysis of deterministic service time tree networks  

Microsoft Academic Search

In this paper we analyze feedforward tree networks of queues serving fixed length packets. Using sample path conservation properties and stochastic coupling techniques, we analyze these systems without making any assumptions about the nature of the underlying input processes. In the case when the server rate is the same for all queues, the exact packet occupancy distribution in any queue

Michael J. Neely; Charles E. Rohrs; Eytan Modiano

2005-01-01

171

A Resource-Allocation Queueing Fairness Measure School of Computer Science  

E-print Network

A Resource-Allocation Queueing Fairness Measure David Raz School of Computer Science Tel, NJ, USA aviitzha@rutcor.rutgers.edu ABSTRACT Fairness is a major issue in the operation of queues, perhaps it is the reason why queues were formed in the first place. Recent studies show that the fairness

Levy, Hanoch

172

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

173

Spacecraft design project multipurpose satellite bus MPS  

NASA Astrophysics Data System (ADS)

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

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

1990-12-01

174

Spacecraft design project multipurpose satellite bus MPS  

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

175

Distributed shared memory multiprocessors using multistage bus networks  

E-print Network

using queueing analysis and execution-driven simulations of various appli- cations. Our execution-driven siinulator is an extended version of Proteus [10] that simu- lates the behavior of a cache coherent distributed shared memory multiprocessor...

Iyer, Ravishankar

1996-01-01

176

Queues, stacks, and transcendentality at the transition to chaos  

NASA Astrophysics Data System (ADS)

We examine the one-humped map at the period-doubling transition to chaos, and ask whether its long-term memory is stack-like (last-in, first-out) or queue-like (first-in, first-out). We show that it can be recognized by a real-time automaton with one queue, or two stacks, and give several new grammatical characterizations of it. We argue that its memory has a queue-like character, since a single stack does not suffice. We also show that its dynamical zeta function, generating function and growth function are transcendental. The same results hold for any period-multiplying cascade. We suggest that transcendentality might be a sign of dynamical phase transitions in other systems as well.

Moore, Cristopher; Lakdawala, Porus

177

Queues, Stacks, and Transcendentality at the Transition to Chaos  

E-print Network

We examine the one-humped map at the period-doubling transition to chaos, and ask whether its long-term memory is stack-like (last-in, first-out) or queue-like (first-in, first-out). We show that it can be recognized by a real-time automaton with one queue, or two stacks, and give several new grammatical characterizations of it. We argue that its memory has a queue-like character, since a single stack does not suffice. We also show that its dynamical zeta function, generating function and growth function are transcendental. The same results hold for any period-multiplying cascade. We suggest that transcendentality might be a sign of dynamical phase transitions in other systems as well.

Cristopher Moore; Porus Lakdawala

1998-12-09

178

Stochastic analyses arising from a new approach for closed queueing networks  

E-print Network

is presented to calculate the system size distribution at an arbitrary point in time and at departures for a ?(n)/G/1/N queue. The analysis is carried out using an embedded Markov chain approach. An algorithm is also developed that combines our analysis.... Specifically, the ?(n)/G/1/N queue is applied to closed networks of a general topology, and a sequential two-queue model consisting of the ?(n)/G/1/N and SM/PH/1/N queues is proposed for tandem queueing networks. v To my Parents and Sister vi ACKNOWLEDGMENTS I...

Sun, Feng

2009-05-15

179

BUS AND RING SYSTEM INTERCONNECTIONS FOR DATA ACQUISITION AND CONTROL  

Microsoft Academic Search

The traditional bus systems based on 8\\/16 bit microcomputer- and register-oriented interfaces for data acquisition and control are analyzed. Bus- and nonbus-type system and network interconnections are compared. The possible transition from traditional bus to indirect point-to-point interconnections for control systems is discussed. The low interaction-rate nodes of message-passing systems can be exchanged for high-rate ones in operating control networks,

V. I. Vinogradov

180

TMS communications hardware. Volume 2: Bus interface unit  

NASA Technical Reports Server (NTRS)

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 described.

Brown, J. S.; Hopkins, G. T.

1979-01-01

181

The SMART MIL-STD-1553 bus adapter hardware manual  

NASA Technical Reports Server (NTRS)

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

Ton, T. T.

1981-01-01

182

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

183

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

184

Empirical findings of Bus Bunching Distributions and Attributes Using Archived AVL/APC Bus Data  

E-print Network

and passenger demand preclude schedule adherence and headway uniformity. A late bus usually encounters more, and uncertain passenger demand (Levison, 1991) (Ceder, 2007). In this study we limit the analysis FENG1 and Miguel FIGLIOZZI2 1 Ph.D. Student, Intelligent Transportation Systems Laboratory, Department

Bertini, Robert L.

185

Spaceborne Fiber Optic Data Bus (SFODB)  

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

186

Two Queues with Alternating Service and Server Breakdown  

Microsoft Academic Search

We consider a queueing system with two stations served by a single server in a cyclic manner. We assume that at most one customer can be served at a station when the server arrives at the station. The system is subject to service interuption that arises from server breakdown. When a server breakdown occurs, the server must be repaired before

Oliver C. Ibe; Kishor S. Trivedi

1990-01-01

187

Feedback Impact Analysis of Queueing System with Stable States  

Microsoft Academic Search

Feedback data packet flow rate control is one of solutions which have been extensively studied. Monitoring the buffer status is the most used method to increase performance of a queueing system. This mathematical approach is most useful for analysis a multivariable transmission network node. In this research we focus on major problem that need to achieve defined level quality of

Ramutis Rindzevicius; P. Tervydis; A. Zvironiene; Zenonas Navickas

2009-01-01

188

MATH 4452 (Ng/Spring 2012) Queueing Models.  

E-print Network

attribute that many service facilities have in common is waiting in line. Since customers' arrival pattern for the operation of the facilities could have no waiting lines at all. Queueing models allow us to analyse the waiting line to start service. For instance, the FCFS (first-come-first-serve) rule, or the LCFS (last

Ng, Peh H.

189

Queueing up for enzymatic processing: correlated signaling through coupled degradation  

E-print Network

, we use queueing theory to investigate how `waiting lines' can lead to correlations between protein unanticipated burden on important cellular workhorses. This can lead to the development of `waiting lines a unifying model for describing how `waiting lines' for processing by a common enzyme (the `servers') can

190

Convergence to Equilibria for Fluid Models of FIFO Queueing Networks  

Microsoft Academic Search

The qualitative behavior of open multiclass queueing networks is currently a topic of considerable activity. An important goal is to formulate general criteria for when such networks possess equilibria, and to characterize these equilibria when possible. Fluid models have recently become an important tool for such purposes. We are interested here in a family of such models, FIFO fluid models

Maury Bramson

1996-01-01

191

Queueing-Theoretic Approaches for Dynamic Scheduling: Daria Terekhova  

E-print Network

, 1994) Flexible manufacturing systems: a review of analyti- cal models (Buzacott and Yao, 1986) Job shop, 1999) Scheduling and control of flexible manufacturing sys- tems: a critical review (Basnet and MizeQueueing-Theoretic Approaches for Dynamic Scheduling: A Survey Daria Terekhova , Douglas G. Downb

Down, Doug

192

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

193

Introduction to Queueing Theory with Applications to Air Transportation  

E-print Network

analytically (in steady state) 2 1 1 1 1 1 q q L L W W Average # in queue Average # in system Average wait · Limitations ­ Model assumes steady-state. Solution does not exist when > 1 (arrival rate exceed service rate · Typically assume steady state · Typically assume stationary process ­ No time of day, day of week

194

Scalability of fork\\/join queueing networks with blocking  

Microsoft Academic Search

This paper investigates how the through put of a general fork-join queueing network with blocking behaves as the number of nodes increases to infinity while the processing speed and buffer space of each node stay unchanged. The problem is motivated by applications arising from distributed systems and computer networks. One example is large-scale distributed stream processing systems where TCP is

Cathy H. Xia; Zhen Liu; Don Towsley; Marc Lelarge

2007-01-01

195

Scalability of fork\\/join queueing networks with blocking  

Microsoft Academic Search

This paper investigates how the throughput of a general fork\\/join queueing network with blocking behaves as the number of nodes increases to infinity while the processing speed and buffer space of each node stay unchanged. The problem is motivated by applications arising from distributed systems and computer networks. One example is large-scale distributed stream processing systems where TCP is used

Cathy H. Xia; Zhen Liu; Donald F. Towsley; Marc Lelarge

2007-01-01

196

Adapting packet fair queueing algorithms to wireless networks  

Microsoft Academic Search

Bit errors are fairly common during transmission in a wirelessnetwork. As a result, a straight-forward application ofexisting packet fair queueing (PFQ) algorithms from wirelineto wireless networks results in an inefficient use of thelimited wireless bandwidth. In this paper, we propose a simpleapproach for adapting the existing PFQ algorithms forthe wireline networks to provide the same kind of long-termfairness guarantees while

Parameswaran Ramanathan; Prathima Agrawal

1998-01-01

197

On Measuring Fairness in Queues Benjamin Avi-Itzhak  

E-print Network

On Measuring Fairness in Queues Benjamin Avi-Itzhak RUTCOR, Rutgers University, New Brunswick, NJ-Aviv, Israel hanoch@cs.tau.ac.il February 29, 2004 Abstract The issue of "fairness" is raised frequently of the fairness of various systems and policies are often awkward due to lack of generally accepted de#12;nitions

Levy, Hanoch

198

Weighted Fairness and Correct Sizing of the Secondary Transit Queue  

E-print Network

Weighted Fairness and Correct Sizing of the Secondary Transit Queue in Resilient Packet Rings Mete a brief overview of the IEEE 802.17 RPR proto- col, this article investigates the weighted fairness networks; Spatial reuse; Fairness. I. INTRODUCTION The IEEE 802.17 Resilient Packet Ring (RPR) is a ring

Ansari, Nirwan

199

A Self-Clocked Fair Queueing Scheme for Broadband Applications  

Microsoft Academic Search

An eficient fair queueing scheme which is feasi- ble for broadband implementation is proposed and its performance is analyzed. We define fairness in a self- contained manner, eliminating the need for the hypo- thetical fluid-flow reference system used in the present state of art and thereby removing the associated com- putational complexity. The scheme is based on the adoption of

S. Jamaloddin Golestani

1994-01-01

200

Flow Management in Packet Networks Through Interacting Queues  

E-print Network

Thomas Meyer and Christian Tschudin Technical Report CS-2011-001 University of Basel January 31st, 2011 Abstract Classical queueing disciplines are work conserving: From the allocated chan- nel's perspective engineering wise, the resulting network dynamics is difficult to handle. In this report, we show

Vetter, Thomas

201

Chapter 2: Fair Queueing 2.1. Introduction  

E-print Network

with FCFS switches, overcome these limitations and provide reasonably fair and efficient conges- tion. Following a similar line of reasoning, Nagle [101] proposed a fair queueing (FQ) algorithm in which switches of free buffers at the destination host, but we are more concerned with their role in limiting the overall

Keshav, Srinivasan

202

Queueing Models for Mobile Ad Hoc Networks Roland de Haan  

E-print Network

Management and Logistics. Beta Dissertation Series D120 Wireless e@sy The research in this thesisQueueing Models for Mobile Ad Hoc Networks by Roland de Haan #12;PhD dissertation committee: prof-filming, and recording, or by any information storage or retrieval system, without the prior written permission

Boucherie, Richard J.

203

Job Queues, Certification Status, and the Education Labor Market  

ERIC Educational Resources Information Center

This research explores the interaction between training programs and certification status in one education labor market to examine the micro-level interactions that shape the recruitment process. Using job queue theory, it is found that the information available to novice teachers operates to stratify and shape their worksite choices in addition…

Evans, Lorraine

2011-01-01

204

Recommendations on Queue Management and Congestion Avoidance in the Internet  

Microsoft Academic Search

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

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

1998-01-01

205

Recommendations on Queue Management and Congestion Avoidance in the Internet  

Microsoft Academic Search

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

Bob Braden

1997-01-01

206

A Multiple Dispatch Queueing Model of Police Patrol Operations  

Microsoft Academic Search

One of the primary concerns of urban police departments is the effective use of patrol cars. In large cities, police assigned to patrol cars typically account for more than 50% of total police manpower and their allocation has become particularly crucial in light of recent fiscal cutbacks. The police patrol system is a complex multi-server queueing system, and recently many

Linda Green

1984-01-01

207

Indoor Air Quality and Occupational Exposures at a Bus Terminal  

Microsoft Academic Search

This article presents an assessment of indoor air quality at a bus terminal. For this purpose, field surveys were conducted, and air samples were collected and analyzed for the presence of selected indoor air quality indicators. Mathematical modeling was performed to simulate bus emission rates, occupational exposure, and ventilation requirements to maintain acceptable indoor air quality. A sensitivity analysis based

Mutasem El-Fadel; Nisrine El-Hougeiri

2003-01-01

208

Design of a Programmable Bus for Microprocessor-Based Systems  

E-print Network

Design of a Programmable Bus for Microprocessor-Based Systems Dr. Kasim M. Al-Aubidy, Muthana A developed to solve several problems in the design and implementation of microprocessor-based systems with normal requirements. Keywords: PC buses, bus systems, microprocessor interfacing, Shared memory

209

OneBusAway: Improving the Usability of Public Transit  

E-print Network

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

Anderson, Richard

210

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

211

GridBus workshop J.P. Gelas L. Lefvre  

E-print Network

­ Thousand of machines ­ Cycles stealing For Grid designers : « networks are simple and do not support Grid applications and middleware » #12;GridBus workshop, 7th June 2003, Melbourne · Grid designers do not care about into intermediate systems to customize network services 1 2 #12;7 GridBus workshop, 7th June 2003, Melbourne FROM

Lefèvre, Laurent

212

A Simultaneous Bus Orientation and Bused Pin Flipping Algorithm  

E-print Network

of the results. A useful characteristic of storage modules is bus pin flipping, that is, when a group of buses module, the bused data input and output pins corresponding to the same internal storage core may formA Simultaneous Bus Orientation and Bused Pin Flipping Algorithm Fan Mo Synplicity fanmo

Brayton, Robert K.

213

Users Perspective on Advanced Fuel Cell Bus Technology  

E-print Network

Users Perspective on Advanced Fuel Cell Bus Technology Lesllie to be `green' ­ Funding opportunityFunding opportunity ­ Learn about the newest technology 2 #12,000 for propulsion related roadcalls · Powerplant that lasts for at least ½ bus life 50% 60% 70% 80% 90% 100% 8 10 12

214

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

215

Red Line/Cedar Avenue Bus Rapid Transitway  

E-print Network

Red Line/Cedar Avenue Bus Rapid Transitway Collaborating to make the Cedar Avenue Transitway'Connell, AICP Dakota County #12;2030 Regional Transitway Vision #12;Cedar Avenue Transitway...... then #12;Cedar Avenue Transitway...today #12;Cedar Avenue Bus Rapid Transit (BRT

Minnesota, University of

216

Power Electric Aiding Controller for Automated Bus Stopping  

E-print Network

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

Paris-Sud XI, Université de

217

'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

218

Cut out Bus Structure and fold as shown.  

E-print Network

the High Gain Antenna Mount to the opposite side of the Bus Structure from the Instrument Assembly. Glue as shown. Cut out the High Gain Antenna Mount and fold as shown. #12;Cut out and fold the Aft StructureCut out Bus Structure and fold as shown. Glue edges labeled "Tab" as shown. Leave the Side Engine

Waliser, Duane E.

219

Network Extender for MIL-STD-1553 Bus  

NASA Technical Reports Server (NTRS)

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

Marcus, Julius; Hanson, T. David

2003-01-01

220

Read This Before You Buy Your Next School Bus.  

ERIC Educational Resources Information Center

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

Shannon, Paul

1981-01-01

221

Bus-based best-practice and urban transport emissions  

NASA Astrophysics Data System (ADS)

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

Enoch, Marcus Paul

222

Home work Dr. S. Iqbal 1. The pin connections the 8088 MPU in Min mode (IC1), address bus latch (IC2), data bus  

E-print Network

Home work Dr. S. Iqbal 1. The pin connections the 8088 MPU in Min mode (IC1), address bus latch (IC2), data bus transceiver buffer (IC3) and the memory system (IC4) is given in the following figure; _______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________ Pin2 Pin3 Pin4 Pin5 DIREN CLKPin1 IC 1 IC 2 IC 4 IC 3 Bus 1 Bus 2 Bus3 MN/MX WR IO/M #12;2. Fill

Iqbal, Sheikh Sharif

223

Mechanical and embedded systems design for Generic Nanosatellite Bus spacecraft  

NASA Astrophysics Data System (ADS)

The adaptation of the University of Toronto Space Flight Laboratory Generic Nanosatellite Bus (GNB) mechanical design to Earth-observation and communications applications is investigated. The ability of this bus to expand the capabilities of low-cost nanosatellites by accommodating large pre-deployed payload appendages, such as antennas, is demonstrated. In addition, the operational architecture of a cold-gas nanosatellite propulsion system, enabling small satellite constellations and formation flying, is described. Component testing of this system has validated compliance with subsystem requirements. Lastly, the design and development of a multi-mission embedded systems generic firmware is described. This firmware consolidates common and critical software functionality, greatly reducing both the risk and cost of developing software for new embedded systems. The firmware has been designed for a distributed-node microcontroller bus architecture in general, and the Nanosatellite for Earth Monitoring and Observation (NEMO) bus and Generic Nanosatellite Bus in particular.

Armitage, Scott Edward

224

Method and systems for a radiation tolerant bus interface circuit  

NASA Technical Reports Server (NTRS)

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

Kinstler, Gary A. (Inventor)

2007-01-01

225

Genetic Algorithm for Multiple Bus Line Coordination on Urban Arterial  

PubMed Central

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

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

2015-01-01

226

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

227

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

SciTech Connect

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

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

1998-11-01

228

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

229

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

PubMed Central

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

2012-01-01

230

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

231

Reading Like a Historian: Montgomery Bus Boycott  

NSDL National Science Digital Library

In this lesson, students analyze primary source documents in an effort to answer the central historical question: Why did the Montgomery Bus Boycott succeed? The teacher first introduces the boycott and Rosa Parks by streaming a film clip from historicalthinkingmatters.org. Students then break into 3 groups and look at a textbook account of the boycott and a timeline, making a “claim” as to why the boycott succeeded and sharing it with the whole class. The groups then corroborate with 2 more documents—a letter by Jo Ann Robinson and a memo by Bayard Rustin—and make another claim. Finally, 2 more documents—a letter by Virginia Durr and a speech by Martin Luther King, Jr.—are added to the mix, and students formulate and share a final claim. In a final class discussion, students reflect on how their claims did/did not change as they encountered more evidence.

Stanford History Education Group

2012-11-06

232

Bus bar electrical feedthrough for electrorefiner system  

DOEpatents

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

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

2013-12-03

233

Research of WLAN CAN Bus Data Test System  

NASA Astrophysics Data System (ADS)

Both controller area network (CAN) and wireless local area network (WLAN) bus technologies are developing rapidly nowadays. But the study on WLAN technology with CAN bus data is relative to be less researched. So a WLAN CAN bus data test system was present in this paper. The system hardware consists of two control modules, each of which consistently allows link test to the CAN bus network. Each hardware of the module is composed by a microcontroller STC12C5410AD, a CAN bus control unit MCP2515, a CAN bus transceiver MCP2551 and a RF wireless module RF903. During the test process, the CAN bus analyzer, Kvaser USBCAN II, receives and dispatches the CAN messages. Test results showed that the system's error score was approximately zero when messages are transmitted and the system can message transmission from one side of CAN panel point to the other side. The communication of the system is suitable for the CAN treaty standard and it can allow wireless message transmission to other suitable networks meeting the CAN treaty standard as well. Finally the system has been applied to the project for hill citrus leaf area index (LAI) acquisition.

Wu, Weibin; Zhu, Yuqing; Hong, Tiansheng; Ye, Cheng; Ye, Zhijie; He, Guangbin; Li, Haobiao

234

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. 6 figs.

Crawford, H.J.; Lindenstruth, V.

1999-06-29

235

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

236

Resource Selection Using Execution and Queue Wait Time Predictions  

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

237

Conservative parallel simulation of priority class queueing networks  

NASA Technical Reports Server (NTRS)

A conservative synchronization protocol is described for the parallel simulation of queueing networks having C job priority classes, where a job's class is fixed. This problem has long vexed designers of conservative synchronization protocols because of its seemingly poor ability to compute lookahead: the time of the next departure. For, a job in service having low priority can be preempted at any time by an arrival having higher priority and an arbitrarily small service time. The solution is to skew the event generation activity so that the events for higher priority jobs are generated farther ahead in simulated time than lower priority jobs. Thus, when a lower priority job enters service for the first time, all the higher priority jobs that may preempt it are already known and the job's departure time can be exactly predicted. Finally, the protocol was analyzed and it was demonstrated that good performance can be expected on the simulation of large queueing networks.

Nicol, David M.

1990-01-01

238

The Effect of Queueing Strategy on Network Traffic  

NASA Astrophysics Data System (ADS)

In recent years, the transportation system has been faced by increasing challenge in congestion and inefficiency, and research in traffic network has become a significant area of interest. In this paper, we introduce a dynamic-information-based (DIB) queueing strategy into network traffic model under the efficient routing strategy. DIB makes a packet with higher priority to be delivered if there are less packets travelling along its path from the current node to the destination. It is found that, compared with the traditional first-in-first-out (FIFO) queueing strategy, DIB can effectively balance the traffic load of the system via delaying packets to be delivered to congested nodes. Although the network capacity has no obvious changes, some other indexes which reflect transportation efficiency are efficiently improved in the congestion state. Besides, extensive simulation results and discussions are provided to explain the phenomena. The results may provide novel insights for research on traffic systems.

Zhang, Xue-Jun; Guan, Xiang-Min; Sun, Deng-Feng; Tang, Shao-Ting

2013-10-01

239

Apollo 14 mission: Inability to disconnect main bus A  

NASA Technical Reports Server (NTRS)

During entry, the Apollo 14 spacecraft busses should have de-energized when the main bus-tie motor switches were switched to the off position. One motor switch did not transfer and main bus A remained energized until the battery bus-tie circuit breakers were opened after landing. Analysis revealed that residual catalyst caused the terminal pin seals to revert to a gummy state. Resulting reversion products then migrated to the motor commutator and caused brush degradation, increased and erratic commutator resistance, and reduced motor torque. The motor stalled when available motor torque was reduced below that required to drive through the maximum torque point of the switch.

1971-01-01

240

Observability Analysis Of Large Bus - System Using Matlab Simulation  

NASA Astrophysics Data System (ADS)

This methodology provides a numerical approach to observability analysis. The approach enables observability analysis and restoration (pseudo-measurement selection) in a simple way with iteration, via triangular factorization of the jacobian matrix of the weight least square state estimator. An algorithm for precious measurement of topological observability in large bus - system state estimation has been proposed. The algorithm is based on observation that the search for a spanning tree of full rank. We use observability algorithm and state estimation algorithm. We use the Mat lab to obtain the various graphs of bus systems. By using simulation method of bus system we analyze the observability.

Gyanendrasingh, Er.; Pratibhatiwari, Prashant Kumar; Srivastava, Tushar

2013-03-01

241

PD-controller: a new active queue management scheme  

Microsoft Academic Search

This paper describes a proportional-differential (PD) control algorithm as a new active queue management (AQM) scheme for TCP\\/IP congestion control. From the viewpoint of the control theory, TCP congestion control system can be regarded as a feedback regulating system. In this paper, a robust AQM called PD-controller is proposed. The design principles of PD-controller are presented in details. Its performance

Jinsheng Sun; Guanrong Chen; King-Tim Ko; Sammy Chan; Moshe Zukerman

2003-01-01

242

Modeling and Simulation of Mixed Queueing and Loss Systems  

Microsoft Academic Search

In this paper, we investigate a multi-rate network in which wide-band calls are allowed to wait if insufficient resources are available at the time of the call arrival. On the link level, an analytical model is presented and simulations have been carried out on the network level. The results indicate that allowing a few wide-band calls to queue can give

Gábor Fodor; Søren Blaabjerg; Allan T. Andersen

1998-01-01

243

Cache-oblivious priority queue and graph algorithm applications  

Microsoft Academic Search

(MATH) In this paper we develop an optimal cache-oblivious priority queue data structure, supporting insertion, deletion, and deletemin operations in O(1 \\\\over B logM\\/BN \\\\over B) amortized memory transfers, where M and B are the memory and block transfer sizes of any two consecutive levels of a multilevel memory hierarchy. In a cache-oblivious data structure, M and B are not

Lars Arge; Michael A. Bender; Erik D. Demaine; Bryan Holland-Minkley; J. Ian Munro

2002-01-01

244

Validating Real Time Specifications using Real Time Event Queue Modeling  

Microsoft Academic Search

Interrupt-driven real time control software is difficult to design and validate. It does not line up well with traditional state-based, timed-transition specification formalisms, due to the complexity of timers and the pending interrupt queue. The present work takes a new approach to the problem of modeling and tool-supported reasoning about such systems based on infinite-state modeling of the temporal event

Robert J. Hall

2008-01-01

245

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.

246

Solar bus regulator and battery charger for IMP's H, I, and J  

NASA Technical Reports Server (NTRS)

Interplanetary Monitoring Probe (IMP) spacecrafts H, I, and J utilize a direct energy transfer (DET) type of power system operating from a solar array source. A shunt type of regulator prevents the bus voltage from exceeding a preset voltage level. The power system utilizes a single differential amplifier with dual outputs to control the battery charge/shunt regulator and the discharge regulator. A two-voltage level, current limited, series charger and a current sensor control battery state of charge of the silver-cadmium battery pack. Premature termination of the battery charge is prevented by a power available gate that also initiates charge current to the battery upon availability of excess power.

Paulkovich, J.

1972-01-01

247

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

SciTech Connect

Contents: part 1--bus operations--service reliability program of the southern california rapid transit district: a test of the short-term impacts on line 26-51; bus route o-d matrix generation: relationship between biproportional and recursive methods; transportation systems management options to improve urban bus route performance using computer simulation; development and application of performance measures for rural public transportation operators; rural public transportation in alaska: present and future options; particulate trap installation in a man articulated transit bus; part 2--paratransit--methodology for conducting a transportation survey of persons with disabilities; marketing rural transit among senior populations; evolution of functional eligibility and certification for paratransit service: the chicago experience; part 3--ridesharing--the state of the commute in southern california; hispanic market research in the southern california market; evaluation of second-year effectiveness of guaranteed ride home service at warner center transportation management organization; effectiveness of a statewide ridesharing promotion: california rideshare week.

Not Available

1992-01-01

248

Analysis of Feeder Bus Network Design and Scheduling Problems  

PubMed Central

A growing concern for public transit is its inability to shift passenger's mode from private to public transport. In order to overcome this problem, a more developed feeder bus network and matched schedules will play important roles. The present paper aims to review some of the studies performed on Feeder Bus Network Design and Scheduling Problem (FNDSP) based on three distinctive parts of the FNDSP setup, namely, problem description, problem characteristics, and solution approaches. The problems consist of different subproblems including data preparation, feeder bus network design, route generation, and feeder bus scheduling. Subsequently, descriptive analysis and classification of previous works are presented to highlight the main characteristics and solution methods. Finally, some of the issues and trends for future research are identified. This paper is targeted at dealing with the FNDSP to exhibit strategic and tactical goals and also contributes to the unification of the field which might be a useful complement to the few existing reviews. PMID:24526890

Almasi, Mohammad Hadi; Karim, Mohamed Rehan

2014-01-01

249

Analysis of feeder bus network design and scheduling problems.  

PubMed

A growing concern for public transit is its inability to shift passenger's mode from private to public transport. In order to overcome this problem, a more developed feeder bus network and matched schedules will play important roles. The present paper aims to review some of the studies performed on Feeder Bus Network Design and Scheduling Problem (FNDSP) based on three distinctive parts of the FNDSP setup, namely, problem description, problem characteristics, and solution approaches. The problems consist of different subproblems including data preparation, feeder bus network design, route generation, and feeder bus scheduling. Subsequently, descriptive analysis and classification of previous works are presented to highlight the main characteristics and solution methods. Finally, some of the issues and trends for future research are identified. This paper is targeted at dealing with the FNDSP to exhibit strategic and tactical goals and also contributes to the unification of the field which might be a useful complement to the few existing reviews. PMID:24526890

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

2014-01-01

250

Study on USB Based CAN Bus for Data Measurement System  

NASA Astrophysics Data System (ADS)

Control area network (CAN) is an international protocol of field bus and universal serial bus (USB) is developing more and more widely. On the other hand, the USB technology combined with the CAN application is still in the development stage, so this research has broad prospects. The USB-based CAN bus system hardware consists of a CAN module, a USB communication module and a micro controller. It has been designed for real-time display and can save the CAN bus message. In addition it has been debugged in actual measurement accompanied by the Kvaser USB CAN II. The test results show that the system can correctly receive all messages frame from Kvaser CanKing. Finally the system has been applied to the project of citrus orchard for transmission of data of the citrus and tree parameters.

Wu, Weibin; Hong, Tiansheng; Zhu, Yuqing; He, Guangbin; Ye, Cheng; Li, Haobiao; Chen, Chuwen

251

Safety evaluation of a PEMFC bus Lionel PERRETTE1  

E-print Network

Safety evaluation of a PEMFC bus Lionel PERRETTE1 , Samira CHELHAOUI1 , David CORGIER2 1 INERIS. The power system is an hybridation between a 75 kW PEMFC and batteries. Batteries are a mean to recover

Paris-Sud XI, Université de

252

A very highly integrated bus coupler for space applications  

NASA Astrophysics Data System (ADS)

One key element of any Data Management System is the Bus Coupler which must allow to control the various equipment and devices of the satellite without penalising the mass and power consumption budgets. This requirement is very stringent for large Telecom Satellites that may need a large amount of bus couplers. To solve this problem, a very small Bus Coupler has been developed for the SPACEBUS 4000 platform that exhibits very attractive performances. It uses very integrated analogue and digital ASICs and MCM technologies to satisfy the power and mass requirements. Its modularity allows for an adaptation to various Spacecraft and Bus standards. It is now fully qualified, and Hi-Rel production has started for Telecom Satellite programs.

Nodet, J. C.; Clouzot, R.

2002-07-01

253

Sustainable transport at MIT : improving area bus services  

E-print Network

Everyday each member of the MIT community makes a decision about how they will travel to school or work. Using the Commuter Habit Survey and information regarding local bus services as guides, this report analyzes the ...

Beasley, Aimee K

2009-01-01

254

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

255

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

256

S-Transform based Directional Bus-bar protection  

Microsoft Academic Search

The directional protection of bus-bars using time- frequency transform such as S-transform is presented in the paper. S-transform is used to estimates the phase and amplitude of the fault current signals during fault situations. The difference in phase angle between positive sequence component of the current during fault and pre-fault conditions distinguishes internal faults (bus-bar faults) from external fault and

S. R. Samantaray; L. N. Tripathy; P. K. Dash; G. Panda

2009-01-01

257

S-transform based directional bus-bar protection  

Microsoft Academic Search

The directional protection of bus-bars using time-frequency transform such as S-transform is presented in the paper. S-transform is used to estimates the phase and amplitude of the fault current signals during fault situations. The difference in phase angle between positive sequence component of the current during fault and pre-fault conditions distinguishes internal faults (bus-bar faults) from external fault and load

S. R. Samantaray; L. N. Tripathy; P. K. Dash; G. Panda

2008-01-01

258

Design of route guidance information for elderly bus passengers  

E-print Network

DESIGN OF ROUTE GUIDANCE INFORMATION FOR ELDERLY BUS PASSENGERS A Thesis by PEI PEI CHENG Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... December 1992 Major Subject: Industrial Engineering DESIGN OF ROUTE GUIDANCE INFORMATION FOR ELDERLY BUS PASSENGERS A Thesis by Pei Pei Cheng Approved as to style and content by: Rodger J. ppa (Chair of Committee) R. Dale Huchingson (Member) Olga...

Cheng, Pei Pei

1992-01-01

259

Personal digital assistant (PDA) based I2C bus analysis  

Microsoft Academic Search

Personal digital assistants are lightweight, inexpensive, and ubiquitous. Furthermore, they have desktop class operating systems features supported by industrial strength development tools. These devices provide an ideal platform for deploying a practical platform for I2C bus analysis. In this paper, we propose a low-cost, highly portable I2C bus analyzer on a PalmOS based PDA. We describe the hardware interface, the

J. W. Bruce; M. A. Gray; R. F. Follett

2003-01-01

260

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

261

Hardware Design of Automobile Door with Local Interconnect Network Bus  

Microsoft Academic Search

In this paper, we presented a hardware design example of automobile door with local interconnect network (LIN) bus. The LIN bus based automobile door has follow functions: manual or auto lift and auto lift out the car, auto anti-pinch, enable\\/disable the lift motor, central controlled door lock, door-controlled top lamp of cockpit, auto unlocking and locking, and so on. In

Zhaoxia Xiao; Youcheng Li

2011-01-01

262

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

263

Markov Chain Analysis of Packet-Switched Banyans with Arbitrary Switch Sizes, Queue Sizes, Link Multiplicities and Speedups  

Microsoft Academic Search

Approximate Markov chains for the performance of banyan networks built with basic switches of arbitrary size containing input queues, output queues or a combination of input buffers and output queues are presented. These chains are also extended to model banyans where each link is replaced by a number of parallel links. Comparison with simulations indicates that the chains are reasonably

Ted H. Szymanski; Salman Z. Shaikh

1989-01-01

264

Design and Implementation of a Per-Flow Queue Manager for an ATM Switch using FPGA technology  

Microsoft Academic Search

Advanced Switches and routers rely mostly on Dynamic RAM technology for providing large, low-cost buffer space needed due to the burstiness of Internet traffic. Quality of Service is also desirable, therefore, per flow queueing of traffic is often implemented. We designed and implemented a queue manager that supports per flow queueing of thousands of flows of ABR traffic for an

Dimitrios S. Kapsalis

2002-01-01

265

Goodput Analysis of a Fluid Queue with Selective Discarding and a Responsive Bursty Source  

E-print Network

Goodput Analysis of a Fluid Queue with Selective Discarding and a Responsive Bursty Source Parijat distribution. The queue employs a threshold discarding policy in the sense that only those bursts at whose ratio to different parameters, in selecting optimal discarding threshold etc. which will further provide

266

Technical Report Analysis of the Early Packet Discard with per-VC Queueing  

E-print Network

Technical Report Analysis of the Early Packet Discard with per-VC Queueing Mechanism K. Spaey April 1999 Abstract The Early Packet Discard (EPD) with per-VC Queueing mechanism is a packet discard scheme measures such as bu er occupation, packet discard ratio and cell loss ratio when parameters of the input

267

Design and Analysis of a Stable Queue Control Scheme for the Internet  

Microsoft Academic Search

The recently proposed Active Queue Management (AQM) is an effective method used in Internet routers for congestion control, and to achieve a tradeoff between link utilization and delay. The de facto standard, the Random Early Detection (RED) AQM scheme, and most of its vari- ants use average queue length as a congestion indicator to trigger packet dropping. In this paper,

Naixue Xiong; Yaoxue Zhang; Laurence T. Yang; Yuezhi Zhou; Yingshu Liz

268

STABILIZING PERFORMANCE IN NETWORKS OF QUEUES WITH TIME-VARYING ARRIVAL RATES  

E-print Network

-forward queueing networks of an algorithm to set staffing levels (the number of servers) to stabilize performance. Keywords: staffing algorithms for service systems; time-varying arrival rates; many-server queues allocating critical resources, such as the number of beds, nurses and associated equipment in a hospital ward

Whitt, Ward

269

MONOTONICITY PROPERTIES FOR MULTISERVER QUEUES WITH RENEGING AND FINITE WAITING LINES  

Microsoft Academic Search

We consider a markovian multiserver queue with a flnite waiting line in which a cus- tomer may decide to leave and give up service if its waiting time in queue exceeds its random deadline. We focus on the performance measure in terms of the probability of being served under both transient and stationary regimes. We investigate monotonicity properties of flrst

Oualid Jouini; Yves Dallery

2007-01-01

270

QueueTrak: Automated Line Length Detection using a Wireless Sensor Network  

E-print Network

waiting in lines and, in general, make fewer purchases at locations with long lines. People often forgoQueueTrak: Automated Line Length Detection using a Wireless Sensor Network Jared Alexander, Matthew to detect and report the length of lines in retail environments. QueueTrak has two components. First

Whitehouse, Kamin

271

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

272

Bayesian control of the number of servers in a GI \\/ M \\/ c queueing system  

Microsoft Academic Search

In this paper we consider the problem of designing a GI\\/M\\/c queueing system. Given arrival and service data, our objective is to choose the optimal number of servers so as to minimize an expected cost function which depends on quantities, such as the number of customers in the queue. A semiparametric approach based on Erlang mixture distributions is used to

M. Concepción Ausín; Rosa E. Lillo; Michael P. Wiper

2007-01-01

273

A Dynamical Queue Approach to Intelligent Task Management for Human Operators  

E-print Network

several scenarios in commerce, industry, health-care, public service and engineering domains. An extensive, where the service time depends on the server utilization history. The proposed queueing model as a function of mental arousal. The focus of the paper is to characterize the throughput of the dynamical queue

Savla, Ketan

274

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

275

On Markov-Krein Characterization of Mean Sojourn Time in Queueing  

E-print Network

, Tchebychef systems, Light traffic analysis #12;Abstract We present a new analytical tool for three queueing/G/k system in light-traffic asymptote and given first n (= 2, 3) moments of the job size distribution of Completely Monotone (CM) distributions, then for all the three queueing systems, for any n, the extremal

Gupta, Varun

276

State space collapse with application to heavy traffic limits for multiclass queueing networks  

Microsoft Academic Search

Heavy traffic limits for multiclass queueing networks are a topic of continuing interest. Presently, the class of networks for which these limits have been rigorously derived is re- stricted. An important ingredient in such work is the demonstration of state space collapse. Here, we demonstrate state space collapse for two families of networks, first-in first-out (FIFO) queueing networks of Kelly

Maury Bramson

1998-01-01

277

Queueing Syst DOI 10.1007/s11134-013-9389-z  

E-print Network

to buy tickets for a show. The associated queueing system is comprised of heads of groups, where each,11] and [17]). Van Oyen and Teneketzis [21] formulated a central data base system and an auto- mated guided-queue polling-type system with a single server. Service is given in batches, where the batch sizes are unlimited

Yechiali, Uri

278

Queueing Syst (2014) 78:3156 DOI 10.1007/s11134-013-9389-z  

E-print Network

waiting line of individuals formed in order to buy tickets for a show. The associated queueing system base system and an auto- mated guided vehicle (AGV) as a polling system with an infinite capacity batch Model 29(3):353­379, 2013) is a multi-queue polling-type system with a single server. Service is given

Yechiali, Uri

279

Some Results on Multiscale Queueing Analysis Trang Dinh Dang, Sandor Molnar, Istvan Maricza  

E-print Network

Some Results on Multiscale Queueing Analysis Trang Dinh Dang, S´andor Moln´ar, Istv´an Maricza High, E-mail: trang, molnar, maricza @ttt-atm.ttt.bme.hu Abstract-Based on a general multifractal queueing

Molnár, Sándor

280

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

281

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

E-print Network

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

Firestone, Jeremy

282

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

283

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

NASA Astrophysics Data System (ADS)

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

Alonge, Akintunde A.; Afullo, Thomas J.

2014-08-01

284

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

PubMed

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

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

2011-01-01

285

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

286

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

287

Application of queueing models to multiprogrammed computer systems operating in a time-critical environment  

NASA Technical Reports Server (NTRS)

A model of a central processor (CPU) which services background applications in the presence of time critical activity is presented. The CPU is viewed as an M/M/1 queueing system subject to periodic interrupts by deterministic, time critical process. The Laplace transform of the distribution of service times for the background applications is developed. The use of state of the art queueing models for studying the background processing capability of time critical computer systems is discussed and the results of a model validation study which support this application of queueing models are presented.

Eckhardt, D. E., Jr.

1979-01-01

288

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

289

Development of a dual-field heteropoplar power converter  

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

290

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

E-print Network

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

Machlab, Farah J. (Farah Jacinthe)

2014-01-01

291

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

NASA Astrophysics Data System (ADS)

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

Nagatani, Takashi

2014-11-01

292

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

2013-01-01

293

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. PMID:23778192

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

2013-01-01

294

Dual oxidases  

PubMed Central

Reactive oxygen species (ROS) have an important role in various physiological processes including host defence, mitogenesis, hormone biosynthesis, apoptosis and fertilization. Currently, the most characterized ROS-producing system operates in phagocytic cells, where ROS generated during phagocytosis act in host defence. Recently, several novel homologues of the phagocytic oxidase have been discovered and this protein family is now designated as the NOX/DUOX family of NADPH oxidases. NOX/DUOX enzymes function in a variety of tissues, including colon, kidney, thyroid gland, testis, salivary glands, airways and lymphoid organs. Importantly, members of the enzyme family are also found in non-mammalian species, including Caenorhabditis elegans and sea urchin. The physiological functions of novel NADPH oxidase enzymes are currently largely unknown. This review focuses on our current knowledge about dual oxidases. PMID:16321800

Donkó, Ágnes; Péterfi, Zalán; Sum, Adrienn; Leto, Thomas; Geiszt, Miklós

2005-01-01

295

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

ERIC Educational Resources Information Center

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

Rannels, Morris W.

296

Fiber Optic Data Bus Using Frequency Division Multiplexing (FDM) And An Asymmetric Coupler  

NASA Astrophysics Data System (ADS)

A fiber optic data bus, using frequency division multiplexing (FDM) is discussed. The use of FDM is motivated by the need to avoid central control of the bus operation. A major difficulty of such a data bus is introduced by the couplers. An efficient low loss access coupler with an asymmetric structure is presented, and manufacturing processes for the coupler are proposed.

Zanger, H.; Webster, L.

1984-08-01

297

Fiber optic data bus using Frequency Division Multiplexing (FDM) and an asymmetric coupler  

NASA Astrophysics Data System (ADS)

A fiber optic data bus, using frequency division multiplexing (FDM) is discussed. The use of FDM is motivated by the need to avoid central control of the bus operation. A major difficulty of such a data bus is introduced by the couplers. An efficient low loss access coupler with an asymmetric structure is presented, and manufacturing processes for the coupler are proposed.

Zanger, M.; Webster, L.

1984-10-01

298

A Metro bus or rail line is always around the corner at  

E-print Network

A Metro bus or rail line is always around the corner at USC, making it easy to get from campus to Downtown, Culver City, Hollywood and more. For information on Metro bus and rail lines, visit metro. Every time you ride a Metro bus or rail line, you make a dent in air pollution and help curb global

Zhou, Chongwu

299

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

E-print Network

Prediction Models ...............................................................6 1.3.7 Identify the Prediction Interval of the Bus Arrival Time...................7 1.3.8 Identify the Probability of a Bus Being on Time... ...................................................................................................191 7.1 SUMMARY.................................................................................................191 7.2 Bus Arrival Time Prediction Models...........................................................191 7...

Jeong, Ran Hee

2005-02-17

300

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

Microsoft Academic Search

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

Jinrui Nan; Li Zai; Zhifu Wang; Jun Wang

2006-01-01

301

Planar bus bar optimum design in high-power converters based on FEM analysis  

Microsoft Academic Search

This paper studies on the design of planar bus bar in the high-power converter. Firstly, the impedance characteristic of planar bus bar and the performance of EMI are analyzed. The design of planar bus bar is restricted by the spatial layout for physical devices. The traditional design method, the partial element equivalent circuit (PEEC), is based on the assumption that

Xiao Zhang; Hui Zhang; Rui-wen Yu; Guo-jun Tan

2010-01-01

302

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

303

Bus network planning for transfers and the network effect in Melbourne, Australia  

Microsoft Academic Search

Although passengers dislike transferring, efficient transit systems should facilitate transfers to provide auto-competitive citywide access. This paper reviews bus transfer behavior in Melbourne, Australia, to understand causal factors. It also explores network effects: high ridership associated with frequent services or simple (grid) networks or both. Half of bus users make transfers, mostly to rail. The number of tram and bus

Graham Currie; Chris Loader

2010-01-01

304

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.

305

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 571...221 Standard No. 221; School bus body joint strength. S1. Scope. This standard...requirements for the strength of the body panel joints in school bus bodies. S2....

2011-10-01

306

Queue counting: The effect of motives upon estimates of numbers in waiting lines  

Microsoft Academic Search

Examined the relationship between actual and apparent (estimated) position in long queues for football tickets, Batman shirts, and chocolate bars. There was a tendency to overestimate numbers ahead in the front part of each line, but after the \\

Leon Mann; K. F. Taylor

1969-01-01

307

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

E-print Network

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

Caldentey, René

2001-01-01

308

An active queue management scheme to contain high bandwidth flows at a congested router  

E-print Network

Incorporating mechanisms in the router to enable end-to-end congestion control is important in order to prevent the network collapse. Routers should be able to recognise misbehaving flows and penalise them. In this thesis, we propose a queue...

Smitha

2001-01-01

309

An advanced time-dependent queueing model for airport delay analysis  

E-print Network

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

Roth, Emily Jane

1979-01-01

310

Queueing model for an ATM multiplexer with unequal input/output link capacities  

NASA Astrophysics Data System (ADS)

We present a queuing model for an ATM multiplexer with unequal input/output link capacities in this paper. This model can be used to analyze the buffer behaviors of an ATM multiplexer which multiplexes low speed input links into a high speed output link. For this queuing mode, we assume that the input and output slot times are not equal, this is quite different from most analysis of discrete-time queues for ATM multiplexer/switch. In the queuing analysis, we adopt a correlated arrival process represented by the Discrete-time Batch Markovian Arrival Process. The analysis is based upon M/G/1 type queue technique which enables easy numerical computation. Queue length distributions observed at different epochs and queue length distribution seen by an arbitrary arrival cell when it enters the buffer are given.

Long, Y. H.; Ho, T. K.; Rad, A. B.; Lam, S. P. S.

1998-10-01

311

A discrete-time queueing network model of a hub-based OBS architecture  

E-print Network

A discrete-time queueing network model of a hub-based OBS architecture Xenia Mountrouidou IBM commercially viable, new Email addresses: {xeniamount}@us.ibm.com (Xenia Mountrouidou), {hp}@ncsu.edu (Harry

Perros, Harry

312

Demonstration of Caterpillar C-10 dual-fuel engines in MCI 102DL3 commuter buses  

SciTech Connect

The purpose of this program was to demonstrate the Caterpillar C-10 Dual-Fuel Natural Gas (DFNG) engine in an over-the-road bus application. Three new Motor Coach Industries (MCI) 102DL3 buses, equipped with Caterpillar C-10 DFNG engines, and one bus, equipped with a Caterpillar C-10 diesel engine, were operated side by side on similar fixed-route revenue service for a 12-month demonstration period (February 1998 to January 1999). The buses were used as part of the Clean Air Express Commuter Bus Program in Santa Barbara County, California. The performance and reliability of the DFNG engines were similar to that of the diesel engine, but the emissions results were mixed.

NONE

2000-02-28

313

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

314

OneBusAway: A Transit Traveller Information System  

E-print Network

OneBusAway: A Transit Traveller Information System Brian Ferris1 , Kari Watkins2 , and Alan Borning Engineering, University of Washington, Seattle, WA Abstract. Public transit is an important tool for those impact. Unfortunately, the usability of transit systems often leaves much to be desired, to the point

Anderson, Richard

315

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

316

School Bus Crash Rates on Routine and Nonroutine Routes  

ERIC Educational Resources Information Center

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

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

2014-01-01

317

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

ERIC Educational Resources Information Center

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

Texas State Dept. of Public Safety, Austin.

318

Bus Rapid Transit: Is Transmilenio a Miracle Cure?  

Microsoft Academic Search

Successful mass transit solutions are rare in poor cities. When they appear they are lauded across the globe and too often copied uncritically. The latest exemplar of such best practice is the ‘Transmilenio’ rapid bus system in Bogotá. The article describes its main characteristics and applauds the improvements that it has already brought to urban transport in Bogotá. Naturally, the

Alan Gilbert

2008-01-01

319

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

320

MODELLING AND CONTROL OF URBAN BUS NETWORKS IN DIOIDS ALGEBRA  

E-print Network

MODELLING AND CONTROL OF URBAN BUS NETWORKS IN DIOIDS ALGEBRA L. Houssin S. Lahaye J.L. Boimond system the- ory. Indeed, concepts such as state representation, transfer matrix, optimal control of railway networks. For our concern, we are interested in applying dioids algebraic tools to the study

Paris-Sud XI, Université de

321

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

322

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.

323

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

324

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

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

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

325

Low-power memory mapping through reducing address bus activity  

Microsoft Academic Search

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

Preeti Ranjan Panda; Nikil D. Dutt

1999-01-01

326

Reducing Address Bus Transitions for Low Power Memory Mapping  

Microsoft Academic Search

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

Preeti R. Panda; Nikil D. Dutt

1996-01-01

327

Route adaptation of control strategies for a hybrid city bus  

Microsoft Academic Search

A series hybrid city bus with diesel engine and electric batteries is studied on a specified route. The study uses two different basic control strategies, “On\\/off” and “Continuous” strategy. These basic strategies are complemented in two ways. First, an “Adviser” strategy which filters the driver commands and gives driver support feedback based on the route data. Second, an “Adapter” strategy,

Jan Andersson; Roger Axelsson; Bengt Jacobson

1999-01-01

328

En bus la Facult de Mdecine et de Pharmacie  

E-print Network

En bus à la Faculté de Médecine et de Pharmacie Le choix des lignes sur le Pôle Santé · Lignes 5 10-ville Fac de Médecine et de Pharmacie : · en 20 à 25 minutes avec la ligne 5 (descendre arrêt Dolto) · en 30

Jeanjean, Louis

329

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

ERIC Educational Resources Information Center

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

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

330

The industrial organization of competition in local bus services  

E-print Network

by bus, which are a major component of regional passenger transportation systems, are subject to the scrutiny of policy makers for at least two contextual reasons. First, while the passenger transport1-2Apr2012 Author manuscript, published in "A handbook of transport economics, De Palma, Lindsey

Paris-Sud XI, Université de

331

STEADY STATE ANALYSIS OF INDUCTION GENERATOR INFINITE BUS SYSTEMS  

Microsoft Academic Search

This paper conducts a fundamental analysis on the induction generator inflnite bus system which is a useful representation for a wind energy converter interfaced to a utility through a transmission line. A third order model is used to represent the induction generator and the resultant nonlinear system equations are analysed to derive a condition that guarantees the existence of equilibrium

Rajesh G. Kavasseri

2007-01-01

332

Research on embedded data display unit based on CAN bus  

Microsoft Academic Search

The application development of embedded display terminal based on ARM microprocessor is studied, by applying 32 bit RISC key microprocessor technique, embedded software technology, embedded GUI (graphics user interface) technology, CAN bus communication technology, information storage and management technology etc.. The design of embedded hardware platform, of which the core is S3C2410CPU, is completed. On the basis, the Linux operation

Peng Yang; Le Yang; Xin Guo

2009-01-01

333

Efficiency and Economy in School Bus Pupil Transportation.  

ERIC Educational Resources Information Center

Areas to analyze in any evaluation of a school bus pupil transportation program are the administrator's role, operations and administration of the program, maps and map system coordination, time schedules for all schools, the recordkeeping system, the reimbursement aid formula, and specifications and bidding on transportation equipment.…

Larsen, Robert A.

1980-01-01

334

Field Report Blood Lead Level and Blood Pressure of Bus  

E-print Network

were significant correlations between PbB and blood pressure both in systolic and diastolic blood pressure after controlling for age, BMI, alcohol consumption, smoking and physical exercise. However, the data on psycho-social factors which may affect on blood pressure of bus drivers were not available

Drivers In Bangkok Thailand; Orawan Kaewboonchoo; Sumlee Saleekul; Arpaporn Powwattana; Toshio Kawai

2006-01-01

335

On GPU Bus Power Reduction with 3D IC Technologies  

E-print Network

On GPU Bus Power Reduction with 3D IC Technologies Young-Joon Lee and Sung Kyu Lim School of ECE how the power consumption of buses in GPUs can be reduced with 3D IC technologies. Based on layout simulations, we found that partitioning and floorplanning of 3D ICs affect the power benefit amount, as well

Lim, Sung Kyu

336

Coronary heart disease risk factors in bus and truck drivers  

Microsoft Academic Search

Fifty-two bus and truck drivers and a control group of 52 male industrial workers were studied with regard to risk factors for coronary heart disease (CHD) as well as some psycho-social and occupational indicators. The main results were: higher mean values for serum cholesterol, serum triglycerides and blood pressure in the driver group, indicating a markedly higher risk of CHD

P. Hartvig; O. Midttun

1983-01-01

337

Levels of Overcrowding in Bus System of Dhaka, Bangladesh  

Microsoft Academic Search

Overcrowded buses are a common sight in Dhaka, Bangladesh, as they swerve between rickshaws and auto-rickshaws and blare their horns, with the next stop announced by a shout. Two primary bus services operate in the city, ticketed and local, differing in fare collection, stop patterns, and price. They carry the largest share of trips in Dhaka, and both are overcrowded.

Donald Katz

2010-01-01

338

CAN bus embedded system for lighting network applications  

Microsoft Academic Search

This paper describes a new embedded system based on CAN bus protocol for remote monitoring and controlling of lighting networks, where the network nodes are lighting lamps and environment sensors. The main characteristic of the embedded system is its non-master capability, allowing interesting applications such as: light dimming control of a single lamp, or a group one, through one lighting

Javier Diaz; Elias Rodriguez; Luis Hurtado; Hugo Cacique; Nimrod Vazquez; Agustin Ramirez

2008-01-01

339

School Bus Safety Advisory Committee: 1999 Annual Report.  

ERIC Educational Resources Information Center

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

Lazenberry, Dennis; Anderson, Barbara

340

Towards optimal placement of surveillance cameras in a bus  

Microsoft Academic Search

Public transport safety is an important issue that has recently gained large attention, especially with the rise of violence happening abroad. To avoid such incidents and to perform post-incident investigations, many buses today are equipped with surveillance cameras. These cameras are usually installed at important places such as doors, the front and the middle of the bus. This camera placement

Khaled Amriki; Pradeep K. Atrey

2011-01-01

341

BUS340: Entrepreneurship & Small Business Management Dr. Jeffrey P. Shay  

E-print Network

BUS340: Entrepreneurship & Small Business Management Dr. Jeffrey P. Shay The Johnson Professor and Zacharakis, Entrepreneurship Timmons and Spinelli, Business Plans that Work Recommended The Wall Street and operate either a new business venture. It concentrates on attributes of entrepreneurs, searching

Marsh, David

342

Manual of First Aid Practices for School Bus Drivers.  

ERIC Educational Resources Information Center

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

Nesbitt, William R.

343

Real life testing of a Hybrid PEM Fuel Cell Bus  

NASA Astrophysics Data System (ADS)

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

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

344

Design and Analysis of a Stable Queue Control Scheme for the Internet  

Microsoft Academic Search

Abstract The recently proposed,Active Queue,Management (AQM) is an effective method,used in Internet routers for congestion control, and to achieve a tradeoff between link utilization and delay. The de facto standard, the Random Early Detection (RED) AQM scheme, and most of its vari- ants use average queue length as a congestion indicator to trigger packet dropping. In this paper, we propose

Naixue Xiong; Laurence Tianruo Yang; Yaoxue Zhang; Yuezhi Zhou; Yingshu Li

2008-01-01

345

On a random area variable arising in discrete-time queues and compact directed percolation  

NASA Astrophysics Data System (ADS)

A well-known discrete-time, single-server queueing system with mean arrival rate lgr and mean departure rate mgr is considered from the perspective of the area, A, swept out by the queue occupation process during a busy period. We determine the exact form of the tail of the distribution, Pr(A > x); in particular, we show that Pr(A > x) ~ Cx-1/4 exp(-Dx1/2) for all rgr \

Kearney, Michael J.

2004-09-01

346

On effects of arrival rate and burstiness in the queueing system: Analysis of Lb \\/ D \\/1  

Microsoft Academic Search

This paper studies a single-server queueing system with deterministic service time in which arrivals are regulated by the leaky-bucket mechanism. This paper intends to improve quantitative understanding of the effects of arrival rate and burstiness on the average delay of queueing systems. The study is directed toward identifying the worst traffic of arrivals allowed by the leaky-bucket regulation and clarifying

Daniel Chonghwan Lee

1996-01-01

347

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

348

Development of the bus joint for the ITER Central Solenoid  

SciTech Connect

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

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

2013-01-01

349

Bus water storage tank as a reservoir of Legionella pneumophila.  

PubMed

Health concerns associated with Legionnaires' disease have been identified as an area of the increasing public and professional interest. Any natural water or man-made water systems worldwide might be reservoirs of Legionellae. We presented a sporadic, community-acquired case of Legionnaires' disease caused by Legionellapneumophila serogroup 1 in a bus driver who used water for hand and face washing from a bus water storage tank. The history of any other usual place of exposure to Legionellae was negative. The water from the tank was dirty, filled with sediment and leaves, at the temperature of 22 degrees C. The water was heavily contaminated with Legionella pneumophila serogroup 1 isolated from each sample with the concentration of 66,000, 16,000, 42,000, 56,000 and 34,000 CFU/L. The disinfection of the bus water storage tank was made using hyperclorination with 50 mg/L of free residual chlorine. The control sampling one week after the disinfection yielded negative results. So far, there are no recommendations on regular management or disinfection of water in bus storage tanks, but it seems to be reasonable to assume that passengers as well as bus drivers may be exposed to Legionella and therefore at risk of acquiring the infection. These recommendations should include regular empting, rinsing and filling the tank with fresh tap water, at least once a week. Finally, we have to be aware that Legionella bacteria are ubiquitous and any potential mode of producing contaminated aerosol should not be overlooked during an epidemiological field investigation and proposed appropriate measures. PMID:25507374

Jur?ev-Savi?evi?, Anamarija; Bradari?, Nikola; Pai?, Vlado Ozic; Muli?, Rosanda; Puntari?, Dinko; Miše, Kornelija

2014-09-01

350

Bus water storage tank as a reservoir of Legionella pneumophila.  

PubMed

Health concerns associated with Legionnaires' disease have been identified as an area of the increasing public and professional interest. Any natural water or man-made water systems worldwide might be reservoirs of Legionellae. We presented a sporadic, community-acquired case of Legionnaires' disease caused by Legionellapneumophila serogroup 1 in a bus driver who used water for hand and face washing from a bus water storage tank. The history of any other usual place of exposure to Legionellae was negative. The water from the tank was dirty, filled with sediment and leaves, at the temperature of 22 degrees C. The water was heavily contaminated with Legionella pneumophila serogroup 1 isolated from each sample with the concentration of 66,000, 16,000, 42,000, 56,000 and 34,000 CFU/L. The disinfection of the bus water storage tank was made using hyperclorination with 50 mg/L of free residual chlorine. The control sampling one week after the disinfection yielded negative results. So far, there are no recommendations on regular management or disinfection of water in bus storage tanks, but it seems to be reasonable to assume that passengers as well as bus drivers may be exposed to Legionella and therefore at risk of acquiring the infection. These recommendations should include regular empting, rinsing and filling the tank with fresh tap water, at least once a week. Finally, we have to be aware that Legionella bacteria are ubiquitous and any potential mode of producing contaminated aerosol should not be overlooked during an epidemiological field investigation and proposed appropriate measures. PMID:25420390

Jur?ev-Savi?evi?, Anamarija; Bradari?, Nikola; Pai?, Vlado Ozic; Muli?, Rosanda; Puntari?, Dinko; Miše, Kornelija

2014-09-01

351

Child pedestrian injuries at tram and bus stops.  

PubMed

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 years) were treated within a 6-year period. Sixteen out of 30 children (53.3%) were injured on their way to school and 3 (10.0%) on their way to kindergarten. Nine out of 30 children (30%) were injured when crossing the street from behind the bus or the tram. Five children (16.7%) were injured by buses, 6 (20.0%) by trams and 19 (63.3%) by passing motorised vehicles. Twelve (40.0%) were injured in the presence of accompanying adults. In 17 of 30 cases (56.7%) the visibility of the vehicle and/or the child was obstructed. The median Injury Severity Score (ISS) was 4.5 (1-75) and the mortality rate 2 out of 30 (6.7%), both children had been killed at bus stops alongside country roads. Nine out of 28 surviving children (32.1%) suffer from minor physical sequelae and 6 (21.4%) from post-traumatic behavioural disturbances. Crossing the road from behind a bus in the area of a stop alongside a country road is extremely dangerous. It is mandatory to increase the safety at bus stops along country roads. PMID:12098543

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

2002-07-01

352

A comparison of queueing, cluster and distributed computing systems  

NASA Technical Reports Server (NTRS)

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

Kaplan, Joseph A.; Nelson, Michael L.

1993-01-01

353

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

354

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

355

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

356

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

357

Dynamics of dc bus networks and their stabilization by decentralized delayed feedback  

NASA Astrophysics Data System (ADS)

The present paper deals with the dynamics of bus networks, which consist of several identical dc bus systems connected by resistors. It is analytically guaranteed that the stability of a stand-alone dc bus system is equivalent to that of the networks, independent of the number of bus systems and the network topology. In addition, we show that a decentralized delayed-feedback control can stabilize an unstable operating point embedded within the networks. Moreover, this stabilization does not depend on the number of bus systems or the network topology. A systematic procedure for designing the controller is presented. Finally, the validity of the analytical results is confirmed through numerical examples.

Konishi, Keiji; Sugitani, Yoshiki; Hara, Naoyuki

2015-01-01

358

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

NASA Astrophysics Data System (ADS)

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

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

2009-05-01

359

Test program to develop vibroacoustics test criteria for the Galileo bus  

NASA Technical Reports Server (NTRS)

In order to define random vibration test requirements for Galileo bus-mounted hardware, an extensive vibroacoustics test program was conducted on hardware available from the previous Voyager spacecraft development program. The Galileo test program consisted of acoustic tests on three configurations of the Voyager Dynamic Test Model bus and shaker random vibration tests on two flight-like bus equipment bay assemblies and one dummy equipment bay assembly. The primary goal of the acoustic tests was to define vibration levels at locations on the bus structure representative of inputs to bus equipment bay assemblies and to obtain response data on bus bay subassemblies for correlation with the vibration tests response data. The primary purpose of the vibration tests was to determine if the vibration tests excited subassembly responses at least as severely as the bus acoustic tests.

Kern, D. L.; Hayes, C. D.

1982-01-01

360

SN54LVTH16245A, SN74LVTH16245A 3.3 V ABT 16 BIT BUS TRANSCEIVERS  

E-print Network

compliant to MIL PRF 38535, all parameters are tested unless otherwise noted. On all other products the A bus to the B bus or from the B bus to the A bus, depending on the logic level at the direction-control.5 V, the devices are in the high-impedance state during power up or power down. However, to ensure

Berns, Hans-Gerd

361

Bus Vent Design Evolution for the Solar Dynamics Observatory  

NASA Technical Reports Server (NTRS)

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

Woronowicz, Michael

2010-01-01

362

Discharging a DC bus capacitor of an electrical converter system  

DOEpatents

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

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

2014-10-14

363

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

364

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

Microsoft Academic Search

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

Jian Hu; Gangyan Li; Xiangpeng Yu; Sheng Liu

2007-01-01

365

BC Transit Fuel Cell Bus Project: Evaluation Results Report  

SciTech Connect

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

Eudy, L.; Post, M.

2014-02-01

366

Crack detection sensor layout and bus configuration analysis  

NASA Astrophysics Data System (ADS)

In crack detection applications large sensor arrays are needed to be able to detect and locate cracks in structures. Emerging graphene-oxide paper sensing skins are a promising technology that will help enable structural sensing skins, but in order to make use of them we must consider how the sensors will be laid out and wired on the skin. This paper analyzes different sensor shapes and layouts to determine the layout which provides the preferred performance. A ‘snaked hexagon’ layout is proposed as the preferred sensor layout when both crack detection and crack location parameters are considered. In previous work we have developed a crack detection circuit which reduces the number of channels of the system by placing several sensors onto a common bus line. This helps reduce data and power consumption requirements but reduces the robustness of the system by creating the possibility of losing sensing in several sensors in the event that a single wire breaks. In this paper, sensor bus configurations are analyzed to increase the robustness of the bused sensor system. Results show that spacing out sensors in the same bus as much as possible increases the robustness of the system and that at least 3 buses are needed to prevent large segments of a structure from losing sensing in the event of a bus failure. This work is a preliminary effort toward enabling a new class of ‘networked materials’ that will be vitally important for next generation structural applications. ‘Networked materials’ have material properties related to information theoretic concepts. An example material property is ‘bandwidth’ per unit of material that might indicate the amount of information the material can provide about its state-of-health.

Sharp, Nathan; Kuntz, Alan; Brubaker, Cole; Amos, Stephanie; Gao, Wei; Gupta, Gautam; Mohite, Aditya; Farrar, Chuck; Mascareñas, David

2014-05-01

367

Solid state power bus controllers for aerospace applications  

E-print Network

's, GTO's, and power BJT's). Also discussed in Baliga's overview are upcoming technologies (MOSIGT's, SIT's, and FCT's). Some of the papers contained in the collection discuss enhancement techniques designed to increase the performance of different.... S. Air Force released a report on a transistorized SSPBC and a study on power device characteristics [11]. This report contains bus information which is necessary for the design of a SSPBC. Also contained in the report are the various tests used...

Villarreal, Terry Joseph

1988-01-01

368

Construction of intelligent greenhouse control system based on CAN bus  

Microsoft Academic Search

An intelligent greenhouse control system based on CAN bus bas been designed according to the needs of greenhouse control. Distributed network control structure has been used and the main control unit uses STM32VBT6 ARM processor as control core to fulfill the function of system programming, command receiving and system status displaying; distribution node uses STM32CBT6 ARM processor as control core

Chen Pengzhan; Liu Baifen

2010-01-01

369

Optical bypass switch for fiber-optic data bus systems.  

PubMed

A new type of optical bypass switch, installed in multimode-fiber data bus systems, was constructed of graded-index rod lenses and movable mirrors. This four-port component is operated mechanically by a small electromagnet and a spring. It has an insertion loss as low as 1.2 dB and a cross talk <-45 dB. Results of endurance, temperature, humidity, and vibration tests for this switch are reported. PMID:20234463

Nunoshita, M; Nomura, Y

1980-08-01

370

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

371

Violence against metropolitan bus drivers and fare collectors in Brazil  

PubMed Central

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

Assunção, Ada Ávila; de Medeiros, Adriane Mesquita

2015-01-01

372

The AI Bus architecture for distributed knowledge-based systems  

NASA Technical Reports Server (NTRS)

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

Schultz, Roger D.; Stobie, Iain

1991-01-01

373

Measuring job quality: a study with bus drivers.  

PubMed

There is growing interest in the contribution which job design can make to worker health; also a desire to better understand the multidimensional notion of 'job quality' and to develop approaches to measuring this. This paper reviews concepts of 'job quality' and 'good jobs' and examines these issues in the work of bus drivers, an occupational group commonly reported as having poor health and poor working conditions. The DGB-Index (Deutscher Gewerkschaftsbund Good Work Index), a tool used recently in Germany for measuring job quality, was translated and administered to a sample of UK bus drivers (n = 381). It found job quality to be significantly lower than that for a group of non-drivers in the same organisation; and better than that for a sample of German bus drivers. We conclude that the DGB-Index is an effective tool for measuring job quality and providing feedback to employers; and could be used to compare job quality between organisations or internationally. PMID:24942323

Jones, Wendy; Haslam, Roger; Haslam, Cheryl

2014-11-01

374

Safety evaluation of a hydrogen fueled transit bus  

SciTech Connect

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

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

1997-12-31

375

A Dimensional Bus model for integrating clinical and research data  

PubMed Central

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

Hum, Richard C; Murphy, James R

2011-01-01

376

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. PMID:12930103

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

2003-01-01

377

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

SciTech Connect

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

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

2014-06-17

378

Multiserver queue with semi-Markovian batch arrivals with application to the MPEG frame sequence  

NASA Astrophysics Data System (ADS)

We consider a queueing system consisting of multiple identical servers and a common queue. The service time follows an exponential distribution and the arrival process is governed by a semi-Markov process (SMP). The motivation to study the queueing system with SMP arrivals lies in that it can model the auto-correlated traffic on the high speed network generated by a real time communication, for example, the MPEG-encoded VBR video. Our analysis is based on the theory of piecewise Markov process. We first derive the distributions of the queue size and the waiting time. When the sojourn time of SMP follows an exponential distribution all the unknown constants contained in the generating function of queue size can be determined through the zeros of the denominator for this generating function. Based on the result of the analysis, we propose a model to evaluate the waiting time of MPEG video traffic on an ATM network with multiple channels. Here, the SMP corresponds to the exact MPEG sequence of frames. Finally, a numerical example using a real video data is shown.

Takagi, Hideaki; Wu, De-An

2002-07-01

379

Unreliable bulk retrial queues with delayed repairs and modified vacation policy  

NASA Astrophysics Data System (ADS)

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

Jain, Madhu; Bhagat, Amita

2014-06-01

380

Using Queueing Theory to Increase the Effectiveness of ED Provider Objectives: Significant variation in emergency department (ED) patient arrival rates  

E-print Network

hospital and used a "Lag SIPP" queueing analysis to gain insights on how to change provider staffing departments. Yet, hospitals often struggle to provide adequate staffing to handle increasing demands for care1 Using Queueing Theory to Increase the Effectiveness of ED Provider Staffing Objectives

Soares, João Luís Cardoso

381

PERFORMANCE ANALYSIS OF CLOCK-REGULATED QUEUES WITH OUTPUT MULTIPLEXING IN THREE DIFFERENT 2 BY 2 CROSSBAR SWITCH ARCHITECTURES  

Microsoft Academic Search

Switches in interconnection networks for highly parallel shared memory computersystems may be implemented with different internal buffer structures. For a 2?á2 synchronousswitch, previous studies have often assumed a switch composed of two queues, oneat each output, each of which has unbounded size and may accept two inputs every clockcycle. Hardware implementations may actually use simpler queue designs and will havebounded

Ora E. Percus; Susan R. Dickey

1990-01-01

382

Fluid Queue Models of Renewable Energy Storage Gareth L. Jones, Peter G. Harrison, Uli Harder, Anthony J. Field  

E-print Network

Fluid Queue Models of Renewable Energy Storage Gareth L. Jones, Peter G. Harrison, Uli Harder in routing and allocating storing energy produced from renewable sources [8]. As renewable power becomes more of networks of fluid queues. Such models can be used to describe the generation and storage of renewable

Imperial College, London

383

Preemptive queueing system with randomized push-out mechanism  

NASA Astrophysics Data System (ADS)

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

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

2015-04-01

384

Folding Proteins at 500 ns/hour with Work Queue  

PubMed Central

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

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

2014-01-01

385

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

386

Small Explorer Data System MIL-STD-1773 fiber optic bus  

NASA Technical Reports Server (NTRS)

The MIL-STD-1773 Fiber Optic Data Bus as implemented in the GSFC Small Explorer Data System (SEDS) for the Small Explorer Program is described. It provides an overview of the SEDS MIL-STD-1773 bus components system design considerations, reliability figures, acceptance and qualification testing requirements, radiation requirements and tests, error handling considerations, and component heritage. The first mission using the bus will be launched in June of 1992.

Flanegan, Mark; Label, Ken

1992-01-01

387

Automated Design and Insertion of Optimal One-Hot Bus Encoders  

Microsoft Academic Search

Tristate buses, commonly used in high-performance designs, raise testability problems because one-hot conditions, required for functional operation, may not be maintained during scan testing. We present a novel method to automatically generate and insert a bus encoder that ensures one-hot bus operation. Each bus is analyzed individually; a customized encoder is then generated and optimized for best testability and minimal

Peter Wohl; John A. Waicukauski; Sanjay Patel

2007-01-01

388

Development of Fuzzy-Based Bus Rear-End Collision Warning Thresholds Using a Driving Simulator  

Microsoft Academic Search

The purpose of this paper is to develop rear-end collision warning thresholds with appropriate values of parameters for busses driving on freeways. Based on a bus-driving simulator, we design a simulation scenario of car following with emergency braking on freeways. Bus drivers working with a bus company are recruited to manipulate the simulation. The perception-reaction time, braking deceleration rate, and

Chien-Yen Chang; Ying-Ru Chou

2009-01-01

389

Double Raman Amplified Bus Networks for Wavelength-Division Multiplexing of Fiber-Optic Sensors  

Microsoft Academic Search

In this paper, three different double Raman fiber bus networks are compared and demonstrated experimentally for the first time as a means of gathering information from wavelength-division-multiplexed optical sensors: the double-bus scheme, the improved double-bus configuration, and the hybrid topology. We report how these structures reduce the received amplified-spontaneous-scattering noise generated. This low-noise configuration yields signal-to-noise ratios over 43 dB

Silvia Diaz; Beatriz Cerrolaza; Gorka Lasheras; Manuel Lopez-Amo

2007-01-01

390

A study of multiplex data bus techniques for the space shuttle  

NASA Technical Reports Server (NTRS)

A comprehensive technology base for the design of a multiplexed data bus subsystem is provided. Extensive analyses, both analytical and empirical, were performed. Subjects covered are classified under the following headings: requirements identification and analysis; transmission media studies; signal design and detection studies; synchronization, timing, and control studies; user-subsystem interface studies; operational reliability analyses; design of candidate data bus configurations; and evaluation of candidate data bus designs.

Kearney, R. J.; Kalange, M. A.

1972-01-01

391

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

Microsoft Academic Search

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

Wang Jianfeng; Wang Dafang; Xiong Jie

2009-01-01

392

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

393

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

DOEpatents

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

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

2014-09-16

394

Heisenberg spin bus as a robust transmission line for quantum-state transfer  

SciTech Connect

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; Hu Xuedong [Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260-1500 (United States); Wu Lianao [Department of Theoretical Physics and History of Science, Basque Country University (EHU/UPV), P.O. Box 644, E-48080 Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, E-48011 Bilbao (Spain); Shim, Yun-Pil; Fei, Jianjia; Friesen, Mark [Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2011-08-15

395

An interactive wireless communication system for visually impaired people using city bus transport.  

PubMed

Visually impaired people have difficulty accessing information about public transportation systems. Several systems have been developed for assisting visually impaired and blind people to use the city bus. Most systems provide only one-way communication and require high-cost and complex equipment. The purpose of this study is to reduce the difficulties faced by visually impaired people when taking city buses, using an interactive wireless communication system. The system comprised a user module and a bus module to establish a direct one-to-one connection. When the user inputs 4-digit numbers, the user module immediately sends out the information. If the bus module receives the matched bus number, it buzzes and the warning LED flashes to notify the bus driver that someone is waiting to board on the bus. User tests were conducted by two visually impaired people in a simulated vehicle and a city bus. The success rate of interactive wireless communication, recognizing the arrival of the bus and boarding the correct bus reached 100% in all of the tests. The interactive wireless communication aid system is a valid and low-cost device for assisting visually impaired people to use city buses. PMID:24776720

Wang, Hsiao-Lan; Chen, Ya-Ping; Rau, Chi-Lun; Yu, Chung-Huang

2014-05-01

396

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

397

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

398

An Interactive Wireless Communication System for Visually Impaired People Using City Bus Transport  

PubMed Central

Visually impaired people have difficulty accessing information about public transportation systems. Several systems have been developed for assisting visually impaired and blind people to use the city bus. Most systems provide only one-way communication and require high-cost and complex equipment. The purpose of this study is to reduce the difficulties faced by visually impaired people when taking city buses, using an interactive wireless communication system. The system comprised a user module and a bus module to establish a direct one-to-one connection. When the user inputs 4-digit numbers, the user module immediately sends out the information. If the bus module receives the matched bus number, it buzzes and the warning LED flashes to notify the bus driver that someone is waiting to board on the bus. User tests were conducted by two visually impaired people in a simulated vehicle and a city bus. The success rate of interactive wireless communication, recognizing the arrival of the bus and boarding the correct bus reached 100% in all of the tests. The interactive wireless communication aid system is a valid and low-cost device for assisting visually impaired people to use city buses. PMID:24776720

Wang, Hsiao-Lan; Chen, Ya-Ping; Rau, Chi-Lun; Yu, Chung-Huang

2014-01-01

399

49 CFR Appendix A to Part 665 - Tests To Be Performed at the Bus Testing Facility  

Code of Federal Regulations, 2011 CFR

...to Part 665 Transportation Other Regulations Relating to Transportation (Continued...DEPARTMENT OF TRANSPORTATION BUS TESTING...whichever speed is lower. Both left...emissions, plus carbon dioxide...

2011-10-01

400

49 CFR Appendix A to Part 665 - Tests To Be Performed at the Bus Testing Facility  

Code of Federal Regulations, 2012 CFR

...to Part 665 Transportation Other Regulations Relating to Transportation (Continued...DEPARTMENT OF TRANSPORTATION BUS TESTING...whichever speed is lower. Both left...emissions, plus carbon dioxide...

2012-10-01

401

49 CFR Appendix A to Part 665 - Tests To Be Performed at the Bus Testing Facility  

Code of Federal Regulations, 2013 CFR

...to Part 665 Transportation Other Regulations Relating to Transportation (Continued...DEPARTMENT OF TRANSPORTATION BUS TESTING...whichever speed is lower. Both left...emissions, plus carbon dioxide...

2013-10-01

402

49 CFR Appendix A to Part 665 - Tests To Be Performed at the Bus Testing Facility  

Code of Federal Regulations, 2014 CFR

...to Part 665 Transportation Other Regulations Relating to Transportation (Continued...DEPARTMENT OF TRANSPORTATION BUS TESTING...whichever speed is lower. Both left...emissions, plus carbon dioxide...

2014-10-01

403

A Queue Simulation Tool for a High Performance Scientific Computing Center  

NASA Technical Reports Server (NTRS)

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

Spear, Carrie; McGalliard, James

2007-01-01

404

[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

405

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

406

DC Bus Regulation with a Flywheel Energy Storage System  

NASA Technical Reports Server (NTRS)

This paper describes the DC bus regulation control algorithm for the NASA flywheel energy storage system during charge, charge reduction and discharge modes of operation. The algorithm was experimentally verified with results given in a previous paper. This paper presents the necessary models for simulation with detailed block diagrams of the controller algorithm. It is shown that the flywheel system and the controller can be modeled in three levels of detail depending on the type of analysis required. The three models are explained and then compared using simulation results.

Kenny, Barbara H.; Kascak, Peter E.

2003-01-01

407

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

408

Implementation of PMSM speed control software based on CAN bus  

NASA Astrophysics Data System (ADS)

In this paper, the driver's hardware structure based on TMS320F28335 is introduced, the control software flow of host computer based on CAN bus is designed, the rule of CAN communication protocol is fulfilled and accordingly the hybrid programming is realized in the background of low speed and large sinusoid operation. This system can realize the CAN communication setting, download the PID parameters to DSP, operate at constant rotate speed and at given large sinusoid rotate speed. Meanwhile the dynamical monitoring and alarm are implemented. Finally the real-time display and storage of measured current, voltage and rotate speed are completed well.

Cao, Wenlun; Chen, Bei; He, Yuyao

2013-03-01

409

BC Transit Fuel Cell Bus Project Evaluation Results: Second Report  

SciTech Connect

Second report evaluating a fuel cell electric bus (FCEB) demonstration led by British Columbia Transit (BC Transit) in Whistler, Canada. BC Transit is collaborating with the California Air Resources Board and the U.S. Department of Energy's National Renewable Energy Laboratory to evaluate the buses in revenue service. NREL published its first report on the demonstration in February 2014. This report is an update to the previous report; it covers 3 full years of revenue service data on the buses from April 2011 through March 2014 and focuses on the final experiences and lessons learned.

Eudy, L.; Post, M.

2014-09-01

410

Dual doubly special relativity  

NASA Astrophysics Data System (ADS)

We develop the physics of dual kappa Poincare algebra, which we will call dual DSR. First, we show that the dual kappa Poincare algebra is isomorphic to de Sitter algebra and its space-time is essentially de Sitter space-time. Second, we show how to derive the coproduct rule for Beltrami and conformal coordinates of de Sitter space-time. It follows from the current literature on de Sitter relativity that the speed of light c and the de Sitter length are the two invariant scales of the physics of dual kappa Poincare. Third, we derive the first Casimir invariant of the dual kappa Poincare algebra and use this to derive an expression for the speed of light, our fourth result. Fifth, the field equation for the scalar field is derived from the Casimir invariant. The results for the coordinate speed of light and the scalar field theory are the same as in de Sitter theory in the planar coordinate basis. Thus, we have shown that the physics of the dual kappa Poincare algebra (in the dual bicrossproduct basis), which can be appropriately called dual DSR, is essentially de Sitter relativity. Sixth, we argue the existence of an observer-independent minimum momentum. Seventh, we argue heuristically that the existence of minimum momentum will lead to a dual generalized uncertainty principle. Finally, we note that dual DSR is not a quantum theory of space-time but a quantum theory of momenta.

Magpantay, Jose A.

2011-07-01

411

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

412

A Conceptual Design for a Reliable Optical Bus (ROBUS)  

NASA Technical Reports Server (NTRS)

The Scalable Processor-Independent Design for Electromagnetic Resilience (SPIDER) is a new family of fault-tolerant architectures under development at NASA Langley Research Center (LaRC). The SPIDER is a general-purpose computational platform suitable for use in ultra-reliable embedded control applications. The design scales from a small configuration supporting a single aircraft function to a large distributed configuration capable of supporting several functions simultaneously. SPIDER consists of a collection of simplex processing elements communicating via a Reliable Optical Bus (ROBUS). The ROBUS is an ultra-reliable, time-division multiple access broadcast bus with strictly enforced write access (no babbling idiots) providing basic fault-tolerant services using formally verified fault-tolerance protocols including Interactive Consistency (Byzantine Agreement), Internal Clock Synchronization, and Distributed Diagnosis. The conceptual design of the ROBUS is presented in this paper including requirements, topology, protocols, and the block-level design. Verification activities, including the use of formal methods, are also discussed.

Miner, Paul S.; Malekpour, Mahyar; Torres, Wilfredo

2002-01-01

413

[Drugs use assessment in a group of bus drivers].  

PubMed

Bus driver is one of those tasks inherent transport activity, which involves special risks to safety and health of others and for which it is necessary, according to art. 41 of Decree No. 81/08, to check the consumption of psychoactive substances during the health surveillance. This assumption was investigated in a group of 461 bus drivers of a large trucking company. In medical history, one subject reported a previous history of opiate addiction and another, in the past, occasional taking of cannabis, and at the time of the visit, in no cases the objectivity has shown intoxication or abstinence signs, or signs of parenteral injection. Laboratory tests were found positive in one case of screening texts, not confirmed by subsequent laboratory analysis and a case of positive analysis for confirmation. The worker, temporarily suspended from driving and taken over by the Service for Drug Addiction of competence, was then reinstated in his job, having held that the absence of drug addiction. PMID:23405659

Maccà, I; Maso, S; Marcuzzo, G; Bartolucci, G B

2012-01-01

414

Building distributed rule-based systems using the AI Bus  

NASA Technical Reports Server (NTRS)

The AI Bus software architecture was designed to support the construction of large-scale, production-quality applications in areas of high technology flux, running heterogeneous distributed environments, utilizing a mix of knowledge-based and conventional components. These goals led to its current development as a layered, object-oriented library for cooperative systems. This paper describes the concepts and design of the AI Bus and its implementation status as a library of reusable and customizable objects, structured by layers from operating system interfaces up to high-level knowledge-based agents. Each agent is a semi-autonomous process with specialized expertise, and consists of a number of knowledge sources (a knowledge base and inference engine). Inter-agent communication mechanisms are based on blackboards and Actors-style acquaintances. As a conservative first implementation, we used C++ on top of Unix, and wrapped an embedded Clips with methods for the knowledge source class. This involved designing standard protocols for communication and functions which use these protocols in rules. Embedding several CLIPS objects within a single process was an unexpected problem because of global variables, whose solution involved constructing and recompiling a C++ version of CLIPS. We are currently working on a more radical approach to incorporating CLIPS, by separating out its pattern matcher, rule and fact representations and other components as true object oriented modules.

Schultz, Roger D.; Stobie, Iain C.

1990-01-01

415

Underhood thermal analysis and improvement of a bus with rear engine compartment  

Microsoft Academic Search

Thermal Analysis of a bus with rear engine compartment is carried out based on CFD in order to solving the problem of overheating. The temperature and flow field of the bus engine compartment is investigated at the most serious work conditions, full load hill climbing with low speed at hottest environment temperature. The reason for the overheating and the overheated

Kaiyao Hu; Xiaolong Yang; Jia Yang

2011-01-01

416

Optimal Bus Stop Spacing for Minimizing Transit Operation Cost and Robert L. Bertini2  

E-print Network

1 Optimal Bus Stop Spacing for Minimizing Transit Operation Cost Huan Li1 and Robert L. Bertini2 Abstract With the increasing attention to finance issues relative to transit operation, a bus stop spacing model is generated with the aim at minimizing the operation cost without impact on transit accessibility

Bertini, Robert L.

417

Analysis of a Transit Bus as Probe Vehicle for Arterial Performance Measurement  

E-print Network

Analysis of a Transit Bus as Probe Vehicle for Arterial Performance Measurement Sutti of an arterial. First, we extract data from the bus dispatch system (BDS) of the Tri- County Metropolitan Transit District (TriMet), the transit provider for Portland, Oregon. Then, the performance characteristics

Bertini, Robert L.

418

Where's My Bus Stop? Supporting Independence of Blind Transit Riders with StopInfo  

E-print Network

Where's My Bus Stop? Supporting Independence of Blind Transit Riders with StopInfo Megan Campbell find and verify bus stop locations. We augmented internal information from a major transit agency and is generally usable. Furthermore, the system supports tenets of indepen dence; participants took public transit

Manchak, John

419

Texas A&M Transportation Institute | 2012 Page | 1 Swift Bus Rapid Transit  

E-print Network

Texas A&M Transportation Institute | 2012 Page | 1 Swift Bus Rapid Transit (Community Transit and Everett Transit) SUMMARY Swift bus rapid transit (BRT) is a partnership between two transit agencies (Community Transit and Everett Transit) in the Central Puget Sound Region, WA. Community Transit directly

420

Guidelines for Bus Evacuation and Classroom Instruction in Safe Riding Practices.  

ERIC Educational Resources Information Center

This booklet is intended to aid local school district administrators by providing guidelines for implementing programs on school bus evacuation and safe riding practices. Included are general guidelines for developing and implementing classroom instruction in safe riding practices, detailed guidelines for familiarizing bus drivers and students…

Sowash, Fred W.

421

Research on setting conditions of Bus Rapid Transit (BRT) in Medium-sized cities  

Microsoft Academic Search

In the background that lots of major cities suppress the second industry and develop the third industry in China, medium- sized cities get the opportunity of development, which led to increasingly serious traffic problems. Then, setting Bus Rapid Transit in medium-sized cities is an important way to alleviate the traffic pressure. In this paper, it takes setting conditions of Bus

Pan Yi; Cai Zhilei

2011-01-01

422

Development of monitoring system for series HEV bus with touch panel  

Microsoft Academic Search

In this paper, the monitoring strategies for a series hybrid electric vehicle (SHEV) bus are suggested for the optimal operation of powertrain and detection of abnormal conditions during the initial development of hybrid technologies. The monitoring system receives the messages from four control modules in the SHEV bus through a CAN, and then displays the data in the messages on

Tae-Won Chun; Quang-Vinh Tran; Uk-Don Choi; Heung-Gun Kim

2008-01-01

423

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

E-print Network

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

424

BEAM: Bus Encoding Based on Instruction-Set-Aware Memories Yazdan Aghaghiri  

E-print Network

BEAM: Bus Encoding Based on Instruction-Set-Aware Memories Yazdan Aghaghiri University of Southern ­ This paper introduces a new approach for minimizing power dissipation on the memory address bus. The proposed approach relies on the availability of smart memories that have certain awareness of the instruction format

Pedram, Massoud

425

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

Code of Federal Regulations, 2010 CFR

...total flash cycle. S6.2.3 Vibration, Moisture, Dust, Corrosion...Engineers (SAE) J1133, School Bus Stop Arm, (April 1984...shall meet the criteria for vibration, moisture, dust, corrosion...1983) and SAE J1133, School Bus Stop Arm, (April 1984)...

2010-10-01

426

A low-cost serial control and data bus for airframes  

Microsoft Academic Search

This paper describes an inexpensive serial medium-speed control and data bus (with optional redundancy) designed for use in airframes. The advantages of using a bus (significant reduction in the wire count, wiring weight, and wiring complexity for airframes) are discussed briefly, The choice of low cost, readily available technologies is justified. System design decisions are reviewed with some emphasis on

G. R. Peterson

1994-01-01

427

NREL's Hydrogen-Powered Bus Serves as Showcase for Advanced Vehicle Technologies (AVT) (Brochure)  

SciTech Connect

Brochure describes the hydrogen-powered internal combustion engine (H2ICE) shuttle bus at NREL. The U.S. Department of Energy (DOE) is funding the lease of the bus from Ford to demonstrate market-ready advanced technology vehicles to visitors at NREL.

Not Available

2010-08-01

428

Virtual Optical Bus: An Efficient Architecture for Packet-Based Optical  

E-print Network

Virtual Optical Bus: An Efficient Architecture for Packet-Based Optical Transport Networks Ahmad Rostami and Adam Wolisz Abstract--The virtual optical bus (VOB) is presented as a novel architecture for packet-based optical transport net- works. The VOB is an evolutionary networking architecture based

Wichmann, Felix

429

Bus-based reliability indices and associated costs in the bulk power system  

Microsoft Academic Search

This paper presents a methodology to evaluate the reliability and to calculate interruption costs at the load bus level in the bulk power system (Hierarchical Level II). The method is based on a nonsequential Monte Carlo simulation combined with a linear optimization model in which the load at every bus is represented by two components, a firm and a nonfirm

S. M. Rios; V. P. Vidal; David L. Kiguel

1998-01-01

430

STUDY OF BUS TRANSPORTATION FOR RELIEF OF OVERCROWDEDNESS IN THE ST. LOUIS SCHOOLS.  

ERIC Educational Resources Information Center

PRESENTED IS A REPORT ON WHAT ST. LOUIS, MISSOURI, AND 15 OTHER CITIES HAVING MORE THAN A 300,000 POPULATION ARE DOING WITH RESPECT TO THE USE OF BUS TRANSPORTATION IN RELIEVING OVERCROWDEDNESS RELATIVE TO THE PROCESS OF DESEGREGATION AND INTEGRATION OF THE PUBLIC SCHOOLS. THE REPORT CONTAINS FOUR SECTIONS--(1) BRIEF OVERVIEW OF THE PROBLEM OF BUS

Saint Louis Board of Education, MO.

431

Through Rain, Sleet, Ice, and Snow, the Walking School Bus Still Must Go!  

ERIC Educational Resources Information Center

In this article, the author describes the walking school bus--a physically active and safe method in which young learners can travel to and from school while accompanied by adult volunteers. The walking school bus provides a safe and healthy way for elementary-age children to travel to and from school. Many families who live within walking…

Paquette, Kelli R.

2007-01-01

432

A distributed slack bus model and its impact on distribution system application techniques  

Microsoft Academic Search

Distribution system operating environments are changing rapidly. For example, with the steady and significant increase in dispersed generation expected, planning and operating application techniques must also change. This paper re-evaluates the single slack bus assumption typically employed in steady-state distribution power flow solvers. Specifically, a distributed slack bus model based on the concept of generator domains will be discussed and

Shiqiong Tong; Michael Kleinberg; Karen Miu

2005-01-01

433

Drive Cycle Analysis, Measurement of Emissions and Fuel Consumption of a PHEV School Bus: Preprint  

SciTech Connect

The National Renewable Energy Laboratory (NREL) collected and analyzed real-world school bus drive cycle data and selected similar standard drive cycles for testing on a chassis dynamometer. NREL tested a first-generation plug-in hybrid electric vehicle (PHEV) school bus equipped with a 6.4L engine and an Enova PHEV drive system comprising a 25-kW/80 kW (continuous/peak) motor and a 370-volt lithium ion battery pack. A Bluebird 7.2L conventional school bus was also tested. Both vehicles were tested over three different drive cycles to capture a range of driving activity. PHEV fuel savings in charge-depleting (CD) mode ranged from slightly more than 30% to a little over 50%. However, the larger fuel savings lasted over a shorter driving distance, as the fully charged PHEV school bus would initially operate in CD mode for some distance, then in a transitional mode, and finally in a charge-sustaining (CS) mode for continued driving. The test results indicate that a PHEV school bus can achieve significant fuel savings during CD operation relative to a conventional bus. In CS mode, the tested bus showed small fuel savings and somewhat higher nitrogen oxide (NOx) emissions than the baseline comparison bus.

Barnitt, R.; Gonder, J.

2011-04-01

434

Queueing Analysis of Early Message Discard Policy Parijat Dube Eitan Altman  

E-print Network

1 Queueing Analysis of Early Message Discard Policy Parijat Dube½ Eitan Altman½ ¾ Abstract-- We on the frame loss probabilities or on the delay, discarding mechanisms have to be used. We analyze in this paper the performance of the Early Message Discard (EMD) policy at the buffer, which consists of (1

435

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

436

Optimal Measurement-based Pricing for an M/M/1 Queue  

E-print Network

networks, where pricing can be used to control congestion, and the network can be characterized by a single a suitable pricing scheme, the facility manager can control congestion, of- fer satisfactory qualityOptimal Measurement-based Pricing for an M/M/1 Queue Yezekael Hayel1 and Bruno Tuffin1 IRISA

Tuffin, Bruno

437

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

438

Asymptotics of Closed Fork and Join Queues with Subexponential Service Times1  

E-print Network

,l customers waiting in front of the assembly station who come from line l {1, . . . , L}. Hence, Kl k=1 Nk #12;and waiting times at station k {1, . . . , Kl} in line l {1, . . . , L} and at the assembly Abstract We consider a closed fork and join queueing network where several lines feed a single assembly

Ayhan, Hayriye

439

Intrusions Into Waiting Lines: Does the Queue Constitute a Social System?  

Microsoft Academic Search

Four experiments tested whether a waiting line should be viewed as a social system with norms, roles, and obligations for queuers or whether behavior in a queue can be explained solely by individuals' personal interests and cost versus benefit calculations. The 1st 3 studies demonstrated that Ss were more likely to respond to an intruder than to a service provider

Bernd H. Schmitt; Laurette Dubé; France Leclerc

1992-01-01

440

Queues, customer characteristics and policies for managing waiting-lines in supermarkets  

Microsoft Academic Search

Shoppers leaving four supermarket outlets (two in one of London’s most prosperous boroughs and two in London’s poorest) were questioned about their attitudes towards having to wait in queues, including express checkout lines. The list of interview questions incorporated items designed to assess whether customers possessed Type A or Type B personality traits. It emerged that although Type A inclination

Roger Bennett

1998-01-01

441

IE 172 Laboratory 5: Questions About Queues Dr. T.K. Ralphs  

E-print Network

is the study of how waiting lines (queues) form and dissipate. It was invented in the early 1900s to decide how to have one phone line for each agent, and also some extra phone lines so people can wait and listen. The number of extra phone lines put a limit on how many people can be waiting in line at a time

Ralphs, Ted

442

Individual, Class-based, and Social Optimal Admission Policies in Two-Priority Queues  

E-print Network

Individual, Class-based, and Social Optimal Admission Policies in Two-Priority Queues Feng Chen class 2 customers than the socially optimal policy, which has interesting socio-economic explanation classes of customers. Class 1 customers have preemptive resume priority over class 2 customers. Within

Kulkarni, Vidyadhar G.

443

Core stateless fair queueing: achieving approximately fair bandwidth allocations in high speed networks  

Microsoft Academic Search

Router mechanisms designed to achieve fair bandwidth allocations, like Fair Queueing, have many desirable properties for congestion control in the Internet. However, such mechanisms usually need to maintain state, manage buffers, and\\/or perform packet scheduling on a per flow basis, and this complexity may prevent them from being cost-effectively implemented and widely deployed. In this paper, we propose an architecture

Ion Stoica; Scott Shenker; Hui Zhang

1998-01-01

444

Core-Stateless Fair Queueing: Achieving Approximately Fair Bandwidth Allocations in High Speed Networks  

Microsoft Academic Search

Router mechanisms designed to achieve fair bandwidth allocations, like Fair Queueing, have many desirable properties for congestion control in the Internet. However, such mechanisms usually need to maintain state, manage buffers, and\\/or perform packet scheduling on a per flow basis, and this complexity may prevent them from being cost-effectively implemented and widely deployed. In this paper, we propose an architecture

Ion Stoica; Scott Shenker; Hui Zhang

1998-01-01

445

Packet Fair Queueing Algorithms for Wireless Networks with Location-Dependent Errors  

Microsoft Academic Search

While Packet Fair Queueing (PFQ) algorithms provide both bounded delay and fairness in wired networks, they cannot be applied di- rectly to wireless networks. The key difficulty is that in wireless networks sessions can experience location-dependent channel errors . This may lead to situations in which a session receives significantly less service than it is supposed to, while another receives

T. S. Eugene Ng; Ion Stoica; Hui Zhang

1998-01-01

446

Queueing Systems 42, 355376, 2002 2002 Kluwer Academic Publishers. Manufactured in The Netherlands.  

E-print Network

in The Netherlands. Optimality of D-Policies for an M/G/1 Queue with a Removable Server EUGENE A. FEINBERG Eugene.Feinberg the Israel Science Foundation. #12;356 E.A. FEINBERG AND O. KELLA If the workload is x, the holding cost per

Feinberg, Eugene A.

447

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

448

Queueing Behavior of the Gilbert-Elliott Channel: BCH Codes and Poisson Arrivals  

E-print Network

Queueing Behavior of the Gilbert-Elliott Channel: BCH Codes and Poisson Arrivals Fatemeh Hamidi the correlated-error channel first studied by Gilbert and Elliott in the 1960s. For some arrival processes, one for ran- dom codes on a Gilbert-Elliott erasure channel with Bernoulli arrivals [1]. In this paper, we

Pfister, Henry D.

449

Energy Efficiency in the Low-SNR Regime under Queueing Constraints and Channel Uncertainty  

E-print Network

1 Energy Efficiency in the Low-SNR Regime under Queueing Constraints and Channel Uncertainty Deli Qiao, Mustafa Cenk Gursoy, and Senem Velipasalar Abstract Energy efficiency of fixed-rate transmissions probabilities. The optimal fraction of power allocated to training is identified. Energy efficiency

Gursoy, Mustafa Cenk

450

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

451

Active Methodologies in a Queueing Systems Course for Telecommunication Engineering Studies  

Microsoft Academic Search

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

José Garcia; Ángela Hernandez

2010-01-01

452

Ns Simulator Tests for Random Early Detection (RED) Queue Sally Floyd and Kevin Fall \\Lambda  

E-print Network

be run in our new simulator ns with the command ``test­all­red'', and the input files are availableNs Simulator Tests for Random Early Detection (RED) Queue Management Sally Floyd and Kevin Fall The input files in this document are in the format used by our old simulator, tcpsim. All of these tests can

Floyd, Sally

453

Stability properties of constrained queueing systems and scheduling policies for maximum throughput in multihop radio networks  

Microsoft Academic Search

The stability of a queueing network with interdependent servers is considered. The dependency among the servers is described by the definition of their subsets that can be activated simultaneously. Multihop radio networks provide a motivation for the consideration of this system. The problem of scheduling the server activation under the constraints imposed by the dependency among servers is studied. The

Leandros Tassiulas; Anthony Ephremides

1992-01-01

454

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

E-print Network

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

Crowley, James L.

455

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

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

456

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

E-print Network

Classes, Priorities and Fairness in Queueing Systems David Raz School of Computer Science Tel, the fairness aspects, which are inherent to any preferential system and highly important to customers, have Fairness Measure (RAQFM) to analyze such systems and derive their relative fairness values. Results from

Levy, Hanoch

457

Adaptive Queue-based Chunk Scheduling for P2P Live Streaming  

E-print Network

Adaptive Queue-based Chunk Scheduling for P2P Live Streaming Yang Guo 2 Independence Way Thomson, 11201 Email: yongliu@poly.edu Abstract-- P2P streaming has been popular and is expected to attract even more users. The challenges for P2P streaming have been on its scalability and video viewing quality

Liu, Yong

458

Considering User Behaviours in Active Servers Queue Management A. Djafari Marbini, L. E. Sacks  

E-print Network

Considering User Behaviours in Active Servers Queue Management A. Djafari Marbini, L. E. Sacks the presence of a distributed management system with optimising parameters for CPU usage and data storage more. It was shown by the economist, Vilfredo Pareto, that for a constant amount of money in a society, the spread

Haddadi, Hamed

459

The MAPt/Pht/ Queueing System Barry L. Nelson Michael R. Taaffe  

E-print Network

The MAPt/Pht/ Queueing System Barry L. Nelson · Michael R. Taaffe Department of Industrial. The methods we use, and the results we obtain, are similar to those we presented for the Pht/Pht/ in Nelson #12;1. Introduction In this paper we generalize Nelson and Taaffe (2000a), where we presented

Taaffe, Michael R.

460

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

E-print Network

our objective is to develop a unifying frame- work to obtain well performing control policies of the optimal stochastic control problem and combining results from restless multi- armed bandits and queueing-dimensional birth-and-death process. For linear hold- ing cost, the index can be calculated in closed-form and turns

Ayesta, Urtzi

461

Active Methodologies in a Queueing Systems Course for Telecommunication Engineering Studies  

ERIC Educational Resources Information Center

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

Garcia, J.; Hernandez, A.

2010-01-01

462

Dynamic-CBT - Better Performing Active Queue Management for Multimedia Networking  

Microsoft Academic Search

The explosive increase in the volume and variety of Internet traffic has placed a growing emphasis on congestion control and fairness in Internet routers. Approaches to the problem of congestion, such as active queue management schemes like Random Early Detection (RED) use congestion avoidance techniques and are successful with TCP flows. Approaches to the problem of fairness, such as Fair

Jae Chung; Mark Claypool

463

An Architecture for Game Behavior AI: Behavior Multi-Queues Maria Cutumisu, Duane Szafron  

E-print Network

machines (HSMs; Harel 1987) and behavior scripts are the most popular game techniques for telling an NPCAn Architecture for Game Behavior AI: Behavior Multi-Queues Maria Cutumisu, Duane Szafron}@cs.ualberta.ca Abstract We describe an AI behavior architecture that supports responsive collaborative interruptible

Szafron, Duane

464

On the validity and utility of queueing models of human service systems  

Microsoft Academic Search

Based on observations made during an extensive study of police patrol operations in New York City, we examine the issues of the validity and utility of queueing models of service systems in which adaptive behavior by the (human) customers or servers is likely. We find that in addition to depending on the technical accuracy of its assumptions, the accuracy of

L. Green; P. Kolesar

1987-01-01

465

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

E-print Network

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

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

2010-01-01

466

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

E-print Network

The H­Bus: A Media Acquisition Bus Optimized for Multiple Streams Jeffrey J. Wong, John A, such as a single audio channel, or a single component video signal. ffl Graceful degradation under heavy load ffl

Bove Jr., V. Michael

467

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

Code of Federal Regulations, 2011 CFR

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

2011-04-01

468

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

Code of Federal Regulations, 2014 CFR

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

2014-04-01

469

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

Code of Federal Regulations, 2012 CFR

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

2012-04-01

470

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

Code of Federal Regulations, 2013 CFR

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

2013-04-01

471

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

Code of Federal Regulations, 2010 CFR

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

2010-04-01

472

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

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 is the second results report for the AT fuel cell bus since it was placed in service, and it focuses on the newest data analysis and lessons learned since the previous report. The appendices, referenced in the main report, provide the full background for the evaluation. They will be updated as new information is collected but will contain the original background material from the first report.

Eudy, L.; Chandler, K.

2011-10-01

473

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

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

474

Quantum computation with Josephson qubits using a current-biased information bus  

NASA Astrophysics Data System (ADS)

We propose an effective scheme for manipulating quantum information stored in a superconducting nanocircuit. The Josephson qubits are coupled via their separate interactions with an information bus, a large current-biased Josephson junction treated as an oscillator with adjustable frequency. The bus is sequentially coupled to only one qubit at a time. Distant Josephson qubits without any direct interaction can be indirectly coupled with each other by independently interacting with the bus sequentially, via exciting/deexciting vibrational quanta in the bus. This is a superconducting analog of the successful ion trap experiments on quantum computing. Our approach differs from previous schemes that simultaneously coupled two qubits to the bus, as opposed to their sequential coupling considered here. The significant quantum logic gates can be realized by using these tunable and selective couplings. The decoherence properties of the proposed quantum system are analyzed within the Bloch-Redfield formalism. Numerical estimations of certain important experimental parameters are provided.

Wei, L. F.; Liu, Yu-Xi; Nori, Franco

2005-04-01

475

Development of the Simulator for the On-demand Bus Introduction  

NASA Astrophysics Data System (ADS)

This paper reports the development of the simulator which helps for the introduction of On-demand Bus service. On-demand bus system is new convenient transportation system that passengers will be transported by the vehicles after they reserve a seat. The design of the introduction of On-demand Bus service is very important for the efficient operation, but there is no established theory because it is a new transportation system. The developed simulator performs well to design the On-demand Bus introduction. The result of the real field test in Moriyama City shows the answer from the simulator is realistic and it is useful information for designing efficient On-demand Bus introduction.

Tsubouchi, Kota; Yamato, Hiroyuki; Hiekata, Kazuo

476

Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC  

NASA Technical Reports Server (NTRS)

On view in front of the Headquarters Building, the Zero Emissions (ZE) transit bus attracts an interested group of employees, including Center Director Roy Bridges (second from left in foreground). Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by-product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. Available for viewing by employees, the ZE bus is also being used on tour routes at the KSC Visitor Complex Oct. 26-27.

1999-01-01

477

Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC  

NASA Technical Reports Server (NTRS)

In front of the Headquarters Building at KSC, Center Director Roy Bridges (left) looks at the hydrogen-oxygen driven engine powering a Zero Emissions (ZE) transit bus. Provided by dbb fuel cell engines inc. of Vancouver, Canada, the ZE bus was brought to KSC as part of the Center's Alternative Fuel Initiatives Program. The bus uses a Proton Exchange Membrane fuel cell in which hydrogen and oxygen, from atmospheric air, react to produce electricity that powers an electric motor drive system. The by- product 'exhaust' from the fuel cell is water vapor, thus zero harmful emissions. A typical diesel-powered bus emits more than a ton of harmful pollutants from its exhaust every year. Available for viewing by employees, the ZE bus is also being used on tour routes at the KSC Visitor Complex Oct. 26-27.

1999-01-01

478

The extended DQDB protocol for real time systems  

E-print Network

The objectives of this thesis are to study the DQDB protocol and to extend it for use in a hard real-time environment. The Distributed Queue Dual Bus (DQDB) protocol is the IEEE 802.6 Metropolitan Area Network (MAN) standard. This protocol uses...

Gajiwala, Purvi Ketan

1994-01-01

479

Erasure Node: Performance Improvements for the IEEE 802.6 MAN  

Microsoft Academic Search

Proposes and analyzes a method for increasing the efficiency of a slotted multiaccess data communications network. The unique aspect of this method is that high efficiency can be achieved without much increase in latency or complexity at stations. The necessary hooks for its implementation have been incorporated into the distributed queue dual bus (DQDB) protocol, which is being standardized by

Manoel A. Rodrigues

1990-01-01

480

Reti e Internetworking Riferimento  

E-print Network

rete - tecnologia trasmissiva Rete Elaboratori una rete broadcast #12;Titpi di rete tecnologia peggiore. gestione del canale di comunicazione ·tecnologia trasmissiva: in generale reti broadcast Queue Dual Bus), utilizzato in varie realizzazioni, molto piu' vicino alla tecnologia LAN che WAN

Balsamo, Simonetta

481

Violence against metropolitan bus drivers and fare collectors in Brazil.  

PubMed

OBJECTIVE To analyze the correlation between sociodemographic factors and working conditions of bus workers in a metropolitan area and violence against them. METHODS This cross-sectional study used a nonprobabilistic sample estimated according to the number of workers employed in bus companies located in three cities in the Belo Horizonte metropolitan region in 2012 (N = 17,470). Face-to-face interviews were conducted using a digital questionnaire. The factors associated with violence were analyzed in two stages using Poisson regression, according to each level. The magnitude of the association was evaluated using prevalence ratios with robust variance and a statistical significance of 5%, and 95% confidence intervals were obtained. RESULTS The study sample comprised 782 drivers and 691 fare collectors; 45.0% participants reported at least one act of violence in the workplace in the last 12 months, with passengers being predominantly responsible. The age of the bus workers was inversely associated with violence. Chronic diseases, sickness absenteeism, and working conditions were also associated with violence. CONCLUSIONS The findings on the correlation between violence and working conditions are essential for implementing prevention strategies by transportation service managers.OBJETIVO Analisar associação entre fatores sociodemográficos e de condições de trabalho e violência contra profissionais de ônibus de região metropolitana. MÉTODOS Estudo transversal com amostra não probabilística, estimada segundo quotas do efetivo distribuído nas empresas de ônibus localizadas em três cidades da região metropolitana de Belo Horizonte, em 2012 (n = 17.470). Foram realizadas entrevistas face a face com questionário digital. A análise dos fatores associados à violência foi realizada em duas etapas, pela regressão de Poisson, de acordo com cada nível. A magnitude da associação foi aferida pelas razões de prevalência com variância robusta e significância estatística de 5%. Foram obtidos intervalos de confiança de 95%. RESULTADOS Participaram da pesquisa 782 motoristas e 691 cobradores. Quase metade (45,0%) dos participantes relatou pelo menos um episódio de violência no trabalho nos últimos 12 meses, predominantemente praticado pelos passageiros. A idade do trabalhador rodoviário foi inversamente associada à violência. Doenças crônicas, absenteísmo-doença e condições de trabalho foram associados à violência. CONCLUSÕES As informações trazidas sobre a associação da violência com as condições de trabalho são fundamentais para guiar estratégias de prevenção indicadas aos gestores da produção dos serviços de transporte. PMID:25741657

Assunção, Ada Ávila; Medeiros, Adriane Mesquita de

2015-01-01

482

Dual subspaces of operators  

Microsoft Academic Search

In this note we introduce some new constructions of dual spaces of operators, which are, of course, at the same time, operator spaces in the sense of Pisier (2003) [12]. We exemplify the utility of these constructs by establishing, in this more general setting, a curious and little known result from the theory of dual algebras, namely from Chevreau and

B. Chevreau; I. B. Jung; E. Ko; C. Pearcy

2010-01-01

483

Dual Enrollment Academy Programs  

ERIC Educational Resources Information Center

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

Gonzalez, Nicolas; Chavez, Guadalupe

2009-01-01

484

Risk functionals Dual properties  

E-print Network

Outline Risk functionals Dual properties A collection of risk functionals Risk and information Multiperiod models Acceptability functionals, risk capital functionals and risk deviation functionals: Primal and risk #12;Outline Risk functionals Dual properties A collection of risk functionals Risk and information

Pflug, Georg

485

Novel low cost standardized Nano-Satellite structure bus for LEO missions  

NASA Astrophysics Data System (ADS)

This paper focuses on SRMSAT STRUCTURE BUS which is a standardized Nano-Satellite structure bus. It provides a standard platform for a wide variety of missions in LEO and can be realized in a very short developmental period. The bus was designed and developed for SRMSAT, the SRM University (Sri Ramaswamy Memorial University) student Nano-Satellite, by the undergraduate students and faculty of SRM University in collaboration with Indian Space Research Organization (ISRO). The bus can support payloads up to a mass of 20kg. SRMSAT STRUCTURE BUS has a mass of around 6 kg and dimensions 280mm × 280mm × 280mm with an available volume of 11000 cc. Vibration Testing of the bus has been performed upto 6.7 gRMS. This makes the satellite capable of being launched by any launch vehicle in the world. An innovative PCB mounting design has been introduced in this structure bus which facilitates mounting of a maximum 7 PCB trays independently, each tray capable of holding a 250 mm2 PCB. Structural analysis of SRMSAT STRUCTURE BUS was done using NX Nastran. The boundary conditions for each analysis were defined based on the loading conditions as specified by the launcher, PSLV (Polar Satellite Launch Vehicle). Optimization of each individual component was performed by maintaining a minimum threshold between the local frequencies of the component and global frequencies of the entire satellite. Static, Modal, Harmonic and Random Vibration analysis of the structure bus was performed. This paper also describes the methodology followed in the static and dynamic analysis of the structure bus to finalize the design. The results have been tested and validated at ISRO Satellite Centre, Bangalore with around 90% accuracy and the structure has been certified as a standard structure bus for Nano-satellite missions. In terms of expandability, this structure bus is capable of accommodating deployable solar panels. Also, the payload mounting is not only restricted to th- bottom deck but can also be done in the top or side decks as required for specific missions. This enhances the scope of small satellites which has not been possible with previous satellites of the same size. SRMSAT which utilized this bus was launched on-board PSLV C-18 on 12th October 2011 with the scientific objective of measuring greenhouse gases, namely CO2 and H2O.

Anubhav, T.; Sarwesh, P.; Narayan, V.; Varma, P. A.; Prasad, R. A.; Loganathan, M.; Rao, D. N.; Sriram, S.; Venkatesh, M.

486

Dual fuel Russian urban transit buses: Economical reduced emissions. Export trade information  

SciTech Connect

This study, conducted by Caterpillar, was funded by the US Trade and Development Agency. The scope of this project was to examine the financial and environmental aspects of introducing new alternative fuel engines to the buses of Russia`s public transportation system. The report consists of the following: (1) executive summary; (2) background/overview; (3) 3306 design, development, test; (4) electronic governed engines; (5) Moscow bus testing; (6) conclusions; (7) appendices. The appendices include: (1) Caterpillar emissions lab report; (2) dyno tests -- dual fuel data sheets; (3) 3360 horizontal engine lub tilt test; (4) 1000 hour endurance test -- engine operator sheets; (5) 1000 hour endurance test -- 250 hour check; (6) Caterpillar dual fuel electronic engines; (7) product description -- dual fuel electronic governed engines; (8) California Environmental Protection Agency -- certification of caterpillar electronic governed engines; (9) annual payback data.

NONE

1998-01-01

487

Performance and reliability of the multistage bus network  

SciTech Connect

A Multistage Bus Network (MBN) has been proposed as a viable alternative to the existing interconnection networks. The MBN consists of multiple stages of buses connected in a manner similar to the conventional Multistage Interconnection Networks (MINs) and has the same bandwidth at each stage. Due to the bidirectional nature of the MBN, there exist a number of separate paths between any source and destination pair. Some paths make a U-turn at an intermediate stage switch which is a common ancestor of the source and destination. We present self routing techniques for the various paths. We also present a performance analysis of a synchronous packet switched MBN and compare the results with those of a MIN. Finally we present a reliability analysis of the MBN and show its superiority over the MIN.

Bhuyan, L.N.; Askar, T. [Texas A& M Univ., College Station, TX (United States); Nanda, A.K. [Texas Instruments, Dallas, TX (United States)

1994-12-31

488

Baseline Testing of the Hybrid Electric Transit Bus  

NASA Technical Reports Server (NTRS)

A government, industry and academic cooperative has developed a Hybrid Electric Transit Bus (HETB). Goals of the program include doubling the fuel economy of city transit buses currently in service, and reducing emissions to one-tenth of EPA standards. Unique aspects of the vehicle's power system include the use of ultra-capacitors for the energy storage system and the planned use of a natural gas fueled turbogenerator, to be developed from a small jet engine. At over 17000 kg gross weight, this is the largest vehicle to use ultra-capacitor energy storage. A description of the HETB, the results of performance testing, and future vehicle development plans are the subject of this report.

Brown, Jeffrey C.; Eichenberg, Dennis J.; Thompson, William K.

1999-01-01

489

Low Bus Voltage Hydrazine Arcjet System for Geostationary Satellites  

NASA Astrophysics Data System (ADS)

The capabilities of arcjet propulsion systems were recently extended to accommodate operation on the NASDA Data Relay Test Satellite (DRTS) providing a power bus voltage between 31 and 51.5 VDC. This paper summarizes the newly attained qualification status of the MR 512 arcjet system demonstrating the flexibility of the current design. A redesign of the Power Processing Unit (PPU) became necessary as well as a delta-qualification of the thruster to validate spacecraft integration and to provide compliance with the DRTS satellite environmental requirements. Two types of thrusters with different thrust levels were made available to meet mission requirements. The delta-qualification included a pyro-shock test, vibration tests to a higher level than previously tested, and performance mapping beyond the original range. Included in the paper is an assessment of the PPU performance characteristics as well as the discussion of the system operation and system telemetry.

Zube, Dieter M.; Fye, Dan

1998-07-01

490

A High Efficiency DC Bus Regulator/RPC for Spacecraft Applications  

NASA Technical Reports Server (NTRS)

DC bus voltage regulation may be required in future high powered spacecraft due to the length of the busses or because they are not generated at precise voltage levels. In these cases the regulation range is often only a few percent increase or decrease, but conventional DC voltage regulators switch all the power passing through them, and this level of power switched determines the size and losses in the regulator. A recently developed concept used a low power DC-DC converter in series with the bs to raise or lower the bus voltage over a small range. This partial power processing technique combines the small size and power losses of the low power converter with the ability to regulate, (over a small range) a high power bus. The Series Connected Buck Boost Regulator (SCBBR) described herein provides bus regulation with an efficiency of 98%. The circuit also provides bus switching and overcurrent limiting functions of a Remote Power Controller (RPC). This paper described the circuit design and performance of a breadboard SCBBR configured as a bus voltage regulator providing plus of minus 40% voltage regulation range, bus switching, and overload limiting.

Birchenough, Arthur G.

2003-01-01

491

Prevalence and factors associated with road traffic crash among bus drivers in Hanoi, Vietnam.  

PubMed

Bus provides a main mode of public transport in Vietnam, but the risk of road traffic crash for bus drivers is unknown. This retrospective study estimated the crash prevalence among bus drivers in Hanoi, Vietnam, and identified driver characteristics affecting their crashes. Information on bus crashes for the period 2006-2009 was collected by interviewing drivers from five bus companies in Hanoi using a structured questionnaire. Logistic regression analysis was performed to determine pertinent risk factors affecting the crash prevalence for bus drivers. Of the total 365 participants recruited, 73 drivers reported 76 crashes, giving an overall crash prevalence of 20%. Among the crashed group, three drivers (4%) were involved in two crashes during the past 3 years. Crashes mainly occurred on streets or local roads (81%). Migrant worker (adjusted odds ratio (OR) 4.26, 95% confidence interval (CI) 2.20-8.25) and insufficient income perceived (OR 2.60, 95% CI 1.37-4.93) were identified to be significantly associated with the crash risk. Further prospective and qualitative studies are needed to provide detailed crash characteristics as well as behaviour and perception of bus drivers, so that an effective intervention can be developed to improve road safety and to prevent traffic injury of these drivers. PMID:23190322

La, Quang Ngoc; Lee, Andy H; Meuleners, Lynn B; Van Duong, Dat

2013-01-01

492

Dual Credit/Dual Enrollment and Data Driven Policy Implementation  

ERIC Educational Resources Information Center

The use of dual credit has been expanding rapidly. Dual credit is a college course taken by a high school student for which both college and high school credit is given. Previous studies provided limited quantitative evidence that dual credit/dual enrollment is directly connected to positive student outcomes. In this study, predictive statistics…

Lichtenberger, Eric; Witt, M. Allison; Blankenberger, Bob; Franklin, Doug

2014-01-01

493

Single Axis Attitude Control and DC Bus Regulation with Two Flywheels  

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

494

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

SciTech Connect

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

Chandler, K.; Eudy, L.

2010-01-01

495

Dual stage passive vibration isolation for optical interferometer missions  

NASA Astrophysics Data System (ADS)

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

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

2003-02-01

496

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

497

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

E-print Network

a conductor and it is quite natural to think of the flow of charge as an incompressible fluid. Batteries canFluid Queue Models of Battery Life Gareth L. Jones, Peter G. Harrison, Uli Harder, Tony Field-mail:{gljones,uh,ajf,pgh}@doc.ic.ac.uk Abstract--We investigate how a power-save mode affects the battery life of a device subject

Imperial College, London

498

Nurse-To-Patient Ratios in Hospital Staffing: A Queueing Perspective  

Microsoft Academic Search

The immediate motivation of this paper is California Bill AB 394, legislation which mandates fixed nurse-to-patient staffing ratios as a means to address the current crisis in the quality of health care delivery. Modeling medical units as closed queueing systems, we seek to determine whether or not ratio policies are effective at managing nurse workload. Our many-server asymptotic results suggest

Francis de Véricourt; Otis B. Jennings

2008-01-01

499

Large deviations theory and efficient simulation of excessive backlogs in a GI\\/GI\\/m queue  

Microsoft Academic Search

The problem of using importance sampling to estimate the average time to buffer overflow in a stable GI\\/GI\\/m queue is considered. Using the notion of busy cycles, estimation of the expected time to buffer overflow is reduced to the problem of estimating pn=P (buffer overflow during a cycle) where n is the buffer size. The probability pn is a large

John S. Sadowsky

1991-01-01

500

Delay decomposition at a single server queue with constant service time and multiple inputs  

NASA Technical Reports Server (NTRS)

Two network consisting of single server queues, each with a constant service time, are considered. The external inputs to each network are assumed to follow some general probability distribution. Several interesting equivalencies that exist between the two networks considered are derived. This leads to the introduction of an important concept in delay decomposition. It is shown that the waiting time experienced by a customer can be decomposed into two basic components called self-delay and interference delay.

Ziegler, C.; Schilling, D. L.

1978-01-01