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1

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

2

Real-time communication in FieldBus multiaccess networks  

Microsoft Academic Search

There has been an increasing need of timely and predictablecommunication services for embedded real-time systemsin automated factories and industrial process controls.Work has been done on real-time communicationwith deadline guarantees in point-to-point, token bus\\/tokenring\\/FDDI, and DQDB (Distributed Queue Dual Bus) networks.However, due to the random access nature of theCSMA\\/CD type multiaccess networks, they are not suitablefor applications with stringent timing constraints.

Ching-chih Han; Kang G. Shin

1995-01-01

3

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

4

Enhancement of VolP over IEEE 802.11 WLAN via dual queue strategy  

Microsoft Academic Search

Today's IEEE 802.11 Wireless LAN (WLAN) is an excellent solution for the broadband wireless networking. However, it lacks of the capability to support real-time services such as voice-over-IP (VoIP) properly. In this paper, we present a simple and viable approach to enhance the VoIP performance over the 802.11 WLAN by implementing two queues along with a strict priority queuing on

Jeonggyun Yu; Sunghyun Choi; Jaehwan Lee

2004-01-01

5

Queue Applet  

NSDL National Science Digital Library

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

Gilley, Shad

6

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

Degree Worksheet - Accounting/Dual (The only difference b/w Accounting and Dual is the number Management BUS 340 Business Finance BUS 350 Business Law BUS 450 Strategic Management Degree Worksheet - ACC Worksheet - ACC-Dual Page 2 #12;

7

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

8

A software bus for thread objects  

NASA Technical Reports Server (NTRS)

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

Callahan, John R.; Li, Dehuai

1995-01-01

9

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

10

Modeling and analysis of single bus tightly coupled multiprocessors  

SciTech Connect

This thesis presents and analyses a stochastic queueing model for single bus tightly coupled multiprocessors. The model is based on an experimental single bus multiprocessor in operation at Illinois Institute of Technology. The model is a hierarchical one, with each processor being described by its own submodel. The submodel takes into consideration local task (group) behavior and the prioritized structure of interprocessor communication. A direct numerical analysis of the submodel is done in order to establish future test data. It is shown that each submodel can be reduced to a single queue/server pair with the service rate depending on the number of tasks in the server's queue. An analytic expression for this service rate is derived, and a CPU sensitivity analysis for it is done. Based on this reduction to a queue/server pair, multiprocessor performance (based on net bus throughput) is obtained. An approximate limiting expression for the submodel valid for heavy loads or low CPU speeds is derived and, based on this approximately expression, closed form solutions for throughput increase (over that afforded by a uniprocessor) are obtained for a system consisting of two nonhomogenous processors and for a system consisting of an arbitrary number of homogeneous processors.

Bodnar, B.L.

1986-01-01

11

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

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

A decentralized software bus based on IP multicas ting  

NASA Technical Reports Server (NTRS)

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

Callahan, John R.; Montgomery, Todd

1995-01-01

14

Rationing, Queues, and Black Markets  

Microsoft Academic Search

Several types of rationing and queue mechanisms are compared in a framework of general equilibrium type models under gross substitutability and normality assumptions about consumers' Walrasian demand. During transition from rationing and queues to a market system, a group of low income people loses. The transition involves larger losses for this group if black markets prevail under rationing or queues,

Victor. Polterovich

1993-01-01

15

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

16

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

17

School Bus Safety Report.  

ERIC Educational Resources Information Center

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

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

18

Creative Bus Financing.  

ERIC Educational Resources Information Center

Alternative ways of financing school bus purchases include financing privately through contractors or commercial banks, financing through sources such as insurance companies and pension funds, leasing the buses, or contracting for transportation services. (Author/MLF)

Malone, Wade

1982-01-01

19

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

20

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

ERIC Educational Resources Information Center

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

Blenkinsop, Sean

2012-01-01

21

Dynamics of Priority-Queue Networks  

NASA Astrophysics Data System (ADS)

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

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

22

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

23

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

24

76 FR 37184 - Discretionary Bus and Bus Facilities Program  

Federal Register 2010, 2011, 2012, 2013, 2014

...FTA state of good repair bus and bus facilities initiative funds...percent for the cost of vehicle-related equipment or facilities attributable to compliance...percent for the cost of vehicle related equipment or facilities (including...

2011-06-24

25

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

26

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

27

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

28

A queueing study of peak-rate enforcement for jitter reduction in ATM networks  

Microsoft Academic Search

The success of future broadband packet-switched networks, based on technologies such as the asynchronous transfer mode (ATM), will be heavily dependent upon their ability to provide quality of service (QOS) guarantees to a wide range of traffic classes. A dual-class queueing system is formulated and applied to study the effects of cell spacing within the network premises as a means

Randall Landry; Ioannis Stavrakakis

1994-01-01

29

Bus Centric Rapid Transit  

E-print Network

? Increase essential needs within pedestrian shed ? Maximize use of transit: bus or rail 2 Preliminary Alternatives ? No-Build Alternative ? BRT Lite ? Transportation System Management (TSM) Alternative ? Build Alternatives ? BRT Fully...-Dedicated Curbside Lanes ? BRT Partially-Dedicated Curbside Lanes ? BRT Peak-Hour Dedicated Lanes ? BRT Barrier-Separated Lanes ? Rail 3 TSM vs. Dedicated 21 Table 6-3: Mesa Corridor Project BRT Capital Cost Comparison El Paso RTS Corridors 5 BRT Concept...

Banasiak, J.

2011-01-01

30

Transient approximations in queueing networks  

E-print Network

that provides accurate results while executing much faster than a traditional Monte Carlo simulation. Two closure approximations for the M/1lf/J queue were extended to a Jackson network. These approximations were compared to a Monte Carlo simulation of a... network. Average relative error values of less than 5% were obtained for the mean queue size for all test cases. The closure approximations provided these results in as little as 1/100 of the CPU time required for the Monte Carlo simulation to obtain...

Andrewartha, John Michael

1989-01-01

31

75 FR 23843 - Discretionary Bus and Bus Facilities Program  

Federal Register 2010, 2011, 2012, 2013, 2014

...DEPARTMENT OF TRANSPORTATION Federal Transit Administration Discretionary Bus...Facilities Program AGENCY: Federal Transit Administration (FTA), DOT. ACTION...SUMMARY: The Federal Transit Administration (FTA)...

2010-05-04

32

Pricing computer services: queueing effects  

Microsoft Academic Search

This article studies the effects of queueing delays, and users' related costs, on the management and control of computing resources. It offers a methodology for setting price, utilization, and capacity, taking into account the value of users' time, and it examines the implications of alternative control structures, determined by the financial responsibility assigned to the data processing manager.

Haim Mendelson; HAM MENDELSON

1985-01-01

33

Message passing with queues and channels  

SciTech Connect

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

34

Queueing Systems 36 (2000) 141173 141 A model for rational abandonments from invisible queues  

E-print Network

Queueing Systems 36 (2000) 141­173 141 A model for rational abandonments from invisible queues@ee.technion.ac.il Received 3 August 1999; revised 1 December 1999 We propose a model for abandonments from a queue, due it is shown that a unique equilibrium exists, in which rational abandonments can occur only upon arrival (zero

Shimkin, Nahum

35

Exact emulation of an output queueing switch by a combined input output queueing switch  

Microsoft Academic Search

Combined input-output queueing switches (CIOQ) have better scaling properties than output queueing (OQ) switches. However, a CIOQ switch may have lower switch throughput and, more importantly, it is difficult to control delay in a CIOQ switch due to the existence of multiple queueing points. In this paper, we study the following problem: can a CIOQ switch be designed to behave

Ion Stoica; Hui Zhang

1998-01-01

36

Input and output queueing packet switch with backpressure mode and queue loss mode for two classes  

Microsoft Academic Search

Proposes an N×N input and output queueing packet switch model with both backpressure and queue loss operation mode, where backpressure mode is used for immediate calls and queue loss mode is used for waiting calls. The authors consider a synchronous system with Bernoulli arrivals, and analyze the average system delay and evaluate the loss probability of each class by computer

Masaki Umayabashi; K. Takemori; S. Shiokawa; I. Sasase

1995-01-01

37

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

38

Fluid Models for Multiserver Queues with Abandonments  

Microsoft Academic Search

Deterministic fluid models are developed to provide simple first-order performance descriptions for multiserver queues with abandonment under heavy loads. Motivated by telephone call centers, the focus is on multiserver queues with a large number of servers and nonexponential service-time and time-to-abandon distributions. The first fluid model serves as an approximation for the G\\/GI\\/s + GI queueing model, which has a

Ward Whitt

2006-01-01

39

The robotics bus: a local communications bus for robots  

NASA Astrophysics Data System (ADS)

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

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

2004-12-01

40

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

41

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

42

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

43

A Model of Bus Drivers' Diseases: Risk Factors and Bus Accidents  

Microsoft Academic Search

Bus accident is a major health problem for bus drivers. To identify the risk factors involved in bus accidents and to design a model showing the relation between the risk factors and bus driver's health status, 219 bus drivers who worked for travel agencies in two areas of west and central Iran were enrolled into this study. We used a

G. H. Sadri

2002-01-01

44

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

45

Constructing estimating equations for queue length data  

E-print Network

In this paper we consider the problem of estimating the parameters of a Markov queuing model from discrete time for queuing processes con- cerns continuous observation of the entire queue (for example Aus´in et al., 2004) demonstrated how to compute the maximum likelihood estimate for a GI/G/1 queue based on waiting time data

Pollett, Phil

46

Ring Buffered Network Bus  

NASA Technical Reports Server (NTRS)

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

1997-01-01

47

On retrial queueing model with fuzzy parameters  

NASA Astrophysics Data System (ADS)

This work constructs the membership functions of the system characteristics of a retrial queueing model with fuzzy customer arrival, retrial and service rates. The ?-cut approach is used to transform a fuzzy retrial-queue into a family of conventional crisp retrial queues in this context. By means of the membership functions of the system characteristics, a set of parametric non-linear programs is developed to describe the family of crisp retrial queues. A numerical example is solved successfully to illustrate the validity of the proposed approach. Because the system characteristics are expressed and governed by the membership functions, more information is provided for use by management. By extending this model to the fuzzy environment, fuzzy retrial-queue is represented more accurately and analytic results are more useful for system designers and practitioners.

Ke, Jau-Chuan; Huang, Hsin-I.; Lin, Chuen-Horng

2007-01-01

48

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

49

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

50

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

51

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

52

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

53

Memory Bus Encoding For Low Power 1 Memory Bus Encoding for  

E-print Network

words · For address busses #12;Memory Bus Encoding For Low Power 10 ISQED 2001 Pyramid Code · Cheng etMemory Bus Encoding For Low Power 1 Memory Bus Encoding for Low Power: A Tutorial Wei-Chung Cheng ­ Probabilistic codes · Conclusions #12;Memory Bus Encoding For Low Power 2 ISQED 2001 Power Dissipation Equation

Pedram, Massoud

54

Robust fluid control of multiclass queueing networks  

E-print Network

This thesis applies recent advances in the field of robust optimization to the optimal control of multiclass queueing networks. We develop models that take into account the uncertainty of interarrival and service time in ...

Su, Hua, S.M. Massachusetts Institute of Technology

2006-01-01

55

Performance Bounds for Scheduling Queueing Networks  

E-print Network

The goal of this paper is to assess the improvement in performance that might' be achieved by optimally scheduling a multiclass open queueing network. A stochastic process is defined whose steady-state mean value is less ...

Ou, Jihong

56

Rate-Controlled Static-Priority Queueing  

Microsoft Academic Search

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

Hui Zhang; Domenico Ferrari

1993-01-01

57

The JCMT observing queue and recipe sequencer  

NASA Astrophysics Data System (ADS)

The James Clerk Maxwell Telescope (JCMT), the world's largest sub-mm telescope, will soon be switching operations from a VAX/VMS based control system to a new, Linux-based, Observatory Control System1 (OCS). A critical part of the OCS is the set of tasks that are associated with the observation queue and the observing recipe sequencer: 1) the JCMT observation queue task 2) the JCMT instrument task, 3) the JCMT Observation Sequencer (JOS), and 4) the OCS console task. The JCMT observation queue task serves as a staging area for observations that have been translated from the observer's science program into a form suitable for the various OCS subsystems. The queue task operates by sending the observation at the head of the queue to the JCMT instrument task and then waits for the astronomer to accept the data before removing the observation from the queue. The JCMT instrument task is responsible for running up the set of tasks required to observe with a particular instrument at the JCMT and passing the observation on to the JOS. The JOS is responsible for executing the observing recipe, pausing/continuing the recipe when commanded, and prematurely ending or aborting the observation when commanded. The OCS console task provides the user with a GUI window with which they can control and monitor the observation queue and the observation itself. This paper shows where the observation queue and recipe sequencer fit into the JCMT OCS, presents the design decisions that resulted in the tasks being structured as they are, describes the external interfaces of the four tasks, and details the interaction between the tasks.

Kackley, Russell D.; Rees, Nicholas P.; Walther, Craig; Jenness, Tim

2004-09-01

58

School Bus Accidents and Driver Age.  

ERIC Educational Resources Information Center

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

McMichael, Judith

59

Anticipative control of switched queueing systems  

NASA Astrophysics Data System (ADS)

The relevant dynamics of a queueing process can be anticipated by taking future arrivals into account. If the transport from one queue to another is associated with transportation delays, as it is typical for traffic or productions networks, future arrivals to a queue are known over some time horizon and, thus, can be used for an anticipative control of the corresponding flows. A queue is controlled by switching its outflow between “on” and “off” similar to green and red traffic lights, where switching to “on” requires a non-zero setup time. Due to the presence of both continuous and discrete state variables, the queueing process is described as a hybrid dynamical system. From this formulation, we derive one observable of fundamental importance: the green time required to clear the queue. This quantity allows to detect switching time points for serving platoons without delay, i.e., in a “green wave” manner. Moreover, we quantify the cost of delaying the start of a service period or its termination in terms of additional waiting time. Our findings may serve as a basis for strategic control decisions.

Lämmer, S.; Donner, R.; Helbing, D.

2008-06-01

60

HERMES travels by CAN bus  

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

61

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

62

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

63

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

64

Applications of robust optimization to queueing and inventory systems  

E-print Network

This thesis investigates the application of robust optimization in the performance analysis of queueing and inventory systems. In the first part of the thesis, we propose a new approach for performance analysis of queueing ...

Rikun, Alexander Anatolyevich

2011-01-01

65

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

66

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

67

Queues with Equally Heavy Sojourn Time and Service Requirement Distributions  

E-print Network

when the latter has a regularly varying tail. In contrast, for the M G 1 queue with Pro- cessor Sharing for transforms of the sojourn time distribution. One such model is the M G 1 Processor Sharing queue with service 26 proved that in the M G 1 queue with Processor Sharing PS the tail of the sojourn time distribution

Núñez-Queija, Rudesindo

68

Queueing time for the outbound call management system  

Microsoft Academic Search

The outbound call management (OCM) system was introduced by M. Sarraf (1989), and its performance was analyzed. In that work, although the probability of joining the queue by a random customer was given, the time spent in the queue was not addressed. The average time to empty a queue, once it is formed, is given, along with the average time

M. Sarraf

1989-01-01

69

Dynamic server allocation to parallel queues with randomly varying connectivity  

Microsoft Academic Search

this paper, we consider a queueing model of asingle-hop network with randomly changing connectivity andwe study the effect of varying connectivity on the performanceof the system.The queueing model consists of a single server and Nparallel queues (Fig. 1). The time is slotted. At slot t eachqueue i may be either connected to the server or not; thatis denoted by the

Leandros Tassiulas; Anthony Ephremides

1993-01-01

70

Describing network congestion with an analytic queueing net- work model  

Microsoft Academic Search

In a network with capacity constraints congestion effects such as bottlenecks, spillbacks and gridlocks can be observed. These can be described with a queueing network model. The main challenge of such an approach lies in adequately capturing the between-queue correla- tion, which explains these congestion effects as well as the ir overall network impact. We present an analytic queueing network

Carolina Osorio; Michel Bierlaire

71

Stable Scheduling Policies for Maximizing Throughput in Generalized Constrained Queueing  

E-print Network

reward. In such systems, queues need to be scheduled such that (i) the total reward earned by the system a packet and receives a certain reward. Different rewards are obtained for transmitting packets from different queues, and furthermore, the reward obtained for serving a queue depends on the set

Sarkar, Saswati

72

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

73

Queue Management in Network Processors  

E-print Network

One of the main bottlenecks when designing a network processing system is very often its memory subsystem. This is mainly due to the state-of-the-art network links operating at very high speeds and to the fact that in order to support advanced Quality of Service (QoS), a large number of independent queues is desirable. In this paper we analyze the performance bottlenecks of various data memory managers integrated in typical Network Processing Units (NPUs). We expose the performance limitations of software implementations utilizing the RISC processing cores typically found in most NPU architectures and we identify the requirements for hardware assisted memory management in order to achieve wire-speed operation at gigabit per second rates. Furthermore, we describe the architecture and performance of a hardware memory manager that fulfills those requirements. This memory manager, although it is implemented in a reconfigurable technology, it can provide up to 6.2Gbps of aggregate throughput, while handling 32K in...

Papaefstathiou, I; Kornaros, G; Kachris, C; Mavroidis, I; Nikologiannis, A

2011-01-01

74

76 FR 78732 - FY 2011 Discretionary Funding Opportunity; Section 5309 Bus and Bus Facilities Veterans...  

Federal Register 2010, 2011, 2012, 2013, 2014

...DEPARTMENT OF TRANSPORTATION Federal Transit Administration FY...5309 Bus and Bus Facilities Veterans Transportation and Community Living Initiative AGENCY...FTA), DOT. ACTION: FTA Veterans Transportation and Community Living Initiative...

2011-12-19

75

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Grants and Section 5339 Alternatives Analysis Program AGENCY: Federal Transit Administration...Bus and Bus Facilities and Alternatives Analysis, in support of DOT's Livability Initiative...non-profit organizations. The Alternatives Analysis program makes funds available to...

2011-11-07

76

Evaluation of substation bus schemes considering reliability  

Microsoft Academic Search

The substations' bus schemes used by Taiwan usually adopted “one and a half breaker” for 345kV system, “double bus” for 69\\/161kV system and “single bus with tie” for 22\\/11kV distribution system. This is considering both of the investment costs and reliability of electricity supply. Due to expansion plan of substation and the increasing concern of power supply reliability, considering a

Cheng-Chien Kuo; Fu-Hsien Chen

2010-01-01

77

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

E-print Network

AN IMPROVED BUS SIGNAL PRIORITY SYSTEM FOR NETWORKS WITH NEARSIDE BUS STOPS A Dissertation by WONHO KIM Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of DOCTOR OF PHILOSOPHY December 2004 Major Subject: Civil Engineering AN IMPROVED BUS SIGNAL PRIORITY SYSTEM FOR NETWORKS WITH NEARSIDE BUS STOPS A Dissertation by WONHO KIM Submitted to the Office...

Kim, Wonho

2005-02-17

78

Waiting time dynamics of priority-queue networks  

NASA Astrophysics Data System (ADS)

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

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

2009-05-01

79

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

80

49 CFR 605.19 - Approval of school bus operations.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Approval of school bus operations. 605.19 Section 605.19...TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.19 Approval of...

2013-10-01

81

49 CFR 605.19 - Approval of school bus operations.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Approval of school bus operations. 605.19 Section 605.19...TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.19 Approval of...

2012-10-01

82

CALIBRATION PARTS SHEET 1 The Spacecraft Bus  

E-print Network

of commands, data storage, attitude control, power switching and control. One appended bay is for the radar by an upper equipment module which supports scientific instruments and other equipment. BUS TOP GLUE BUS the spacecraft's attitude, and for small propulsive maneuvers called Trajectory Correction Maneuvers (TCMs

83

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

84

Controlling Multiple Registers on a Computer Bus  

NASA Technical Reports Server (NTRS)

Number of addressable registers increased. Monitoring and controlling interface circuit expands capabilities of DR11-C (or equivalent) input/output port for computer that communicates with peripheral equipment via UNIBUS (or equivalent) data bus. Using only three address locations on bus, unit enables any number of external registers to be addressed, read, or written.

Brokl, Stanley S.

1987-01-01

85

Bus Timetable Effective August 31, 2014  

E-print Network

Only If you think your bus operator deserves an Apple Award -- our special recognition for service that no person is excluded from participation in, or denied the benefits of, or subjected to discrimination for a free electronic paper transfer to use on another local bus. Reduced-Fare Benefits ­ You are eligible

Rosen, Jay

86

Regular-route bus Light rail transit  

E-print Network

#12;· Regular-route bus ­Express ­Local · Light rail transit · Commuter rail · Bus rapid transit the Metropolitan Council. · The Legislature should extend the transit taxing district. · The Legislature should of transit in the Twin Cities region. #12;· Compared to 11 peers, including Denver, Phoenix, Portland

Minnesota, University of

87

Upper Body Quadrant Pain in Bus Drivers  

Microsoft Academic Search

The aims of this study were to evaluate the prevalence of upper body quadrant pain among Israeli professional urban bus drivers and to evaluate the association between individual, ergonomic, and psychosocial risk factors and occurrence of neck pain. Three hundred and eighty-four male urban bus drivers were consecutively enrolled in the study. Data pertaining to work-related ergonomic and psychosocial stress

Deborah Alperovitch-Najenson; Michal Katz-Leurer; Yoav Santo; Diana Golman; Leonid Kalichman

2010-01-01

88

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

89

Control of a heterogeneous two-server exponential queueing system  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

90

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

91

Ultralight Stainless Steel Urban Bus Concept  

SciTech Connect

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

J. Bruce Emmons; Leonard J. Blessing

2001-05-14

92

Efficient Multiqubit Entanglement via a Spin Bus  

NASA Astrophysics Data System (ADS)

We propose an experimentally feasible architecture with controllable long-range couplings built up from local exchange interactions. The scheme consists of a spin bus, with strong, always-on interactions, coupled dynamically to external qubits of the Loss and DiVincenzo type. Long-range correlations are enabled by a spectral gap occurring in a finite-size chain. The bus can also form a hub for multiqubit entangling operations. We show how multiqubit gates may be used to efficiently generate W states (an important entanglement resource). The spin bus therefore provides a route for scalable solid-state quantum computation, using currently available experimental resources.

Friesen, Mark; Biswas, Asoka; Hu, Xuedong; Lidar, Daniel

2007-06-01

93

The design of communication convertor based on CAN bus  

Microsoft Academic Search

With the plentiful application of various electronic equipments and control devices which used in industry, the communication networks based on field bus are produced. Connection between CAN bus and normal bus RS-232 which is used in existing serial communication, could realize to construct network with multidrop and long-distance communication. Method of conversion between RS-232 and CAN bus is discussed and

Ping Ran; Baoqiang Wang; Wei Wang

2008-01-01

94

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

95

An evaluation of a transient queueing approximation for M/M/1 and tandem queues  

E-print Network

AN EVAI, UATION OF A TRANSIENT QliEUEING APPROXIMATION FOR M/M(I AND TANDEM QUFUES A Thesis SIU-HUNG CHU Submitted to the Graduate College of Texas A&:M University in partial fulfillment, of the requirement for the degree of MASTER OF SCIENCF.... May 1985 Major Subject: Electrical Engineering AN EVALUATION OF A TRANSIENT QUEUEING APPROXIMATION FOR M/M/I AND TANDEM QUEUES A Thesis by SIU-HUNG CHU Approved as to style and content by: Fischer. Thomas R. (E. E) (Chairman of Committee...

Chu, Siu-Hung

2012-06-07

96

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

97

Performance and reliability of Multistage Bus Network  

E-print Network

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

Askar, Tahsin

2012-06-07

98

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

99

FLUID MODELS FOR MULTI-SERVER QUEUES WITH ABANDONMENTS  

E-print Network

FLUID MODELS FOR MULTI-SERVER QUEUES WITH ABANDONMENTS by Ward Whitt Department of Industrial-order performance descrip- tions for multi-server queues with abandonment under heavy loads. Motivated by telephone-exponential service-time and time-to-abandon distributions. The first fluid model serves as an approxi- mation

Whitt, Ward

100

Time Varying Multiserver Queues with Abandonment and Retrials  

Microsoft Academic Search

this paper we consider a multiserver queueing model where waiting customers mayabandon and subsequently retry. This model is of particular interest for analyzing performanceand setting staffing levels in call centers. All of the parameters (arrival rate, servicerate, etc.) are allowed to be time dependent. We propose a simple fluid approximationfor the queue length process arising in this model. The fluid

A. Mandelbaum; William A. Massey; Martin I. Reiman; Brian Rider Davidson

1999-01-01

101

Increasing Design Space of the Instruction Queue with Tag Coding  

E-print Network

Increasing Design Space of the Instruction Queue with Tag Coding Junwei Zhou Department of ECE for instruction wakeup from the tags for physical register access, thus increasing the design space, Michigan State University East Lansing, MI 48824 mason@egr.msu.edu ABSTRACT The instruction queue

Mason, Andrew

102

Fractional Brownian Heavy Traffic Approximations of Multiclass Feedforward Queueing Networks  

Microsoft Academic Search

We consider multiclass feedforward queueing networks under first in first out and priority service disciplines driven by long-range dependent arrival and service time processes. We show that in critical loading the normalized workload, queue length and sojourn time processes can converge to a multi-dimensional reflected fractional Brownian motion. This weak heavy traffic approximation is deduced from a deterministic pathwise approximation

Kurt Majewski

2005-01-01

103

Hierarchical Queues: general description and implementation in MAMBA Image library  

E-print Network

of the watersheds and geodesic reconstructions algorithms based on these hierarchical queues. This libraryHierarchical Queues: general description and implementation in MAMBA Image library Nicolas BEUCHER such as watershed lines or geodesic reconstructions. The recent development of MAMBA, new morphological image

Paris-Sud XI, Université de

104

Queues with Equally Heavy Sojourn Time and Service Requirement Distributions  

E-print Network

when the latter has a regularly varying tail. In contrast, for the M/G/1 queue with Pro­ cessor Sharing formulas exist for (transforms of) the sojourn time distribution. One such model is the M/G/1 Processor and Boxma [26] proved that in the M/G/1 queue with Processor Sharing (PS) the tail of the sojourn time

Núñez-Queija, Rudesindo

105

QBETS: Queue Bounds Estimation from Time Series Daniel Nurmi1  

E-print Network

for it to use. When a program must wait before it can be initiated, it is queued as a "job" along with a descrip-come-first-served (FCFS) queuing discipline to manage the queue of waiting jobs. Indeed, a number of queue manage- ment batch-queuing systems to manage processor alloca- tion. Because these machines are typically "space

Feitelson, Dror

106

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

107

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

E-print Network

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

Thain, Douglas

108

Weighted scheduling based on queue length and delay for AOPS  

NASA Astrophysics Data System (ADS)

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

Chen, Qianbin; Pang, Junyu; Liu, Huanlin

2007-11-01

109

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

ERIC Educational Resources Information Center

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

Sowash, Fred W.

110

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.

111

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

112

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

NASA Astrophysics Data System (ADS)

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

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

113

Biased Diffusion and Universality in Model Queues  

NASA Astrophysics Data System (ADS)

We study the structure and robustness of universality classes for queueing, deriving analytic results for priority-based models with continuous-valued priorities. By mapping one model onto the problem of biased diffusion, we show that its distribution of waiting times, P(?), decreases for large times ? as P(?)˜?-3/2 or as P(?)˜?-5/2exp?(-?/?0) in different parameter regimes. In a second model, introducing a cost for switching between different classes of tasks substantially changes the asymptotic behavior of P(?).

Grinstein, G.; Linsker, R.

2006-09-01

114

[Tuberculosis microepidemic in a commuter bus].  

PubMed

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

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

1999-06-01

115

Notes on the fast bus system  

SciTech Connect

In any system there will be modules that gather and process data from the experiment's detectors and perhaps from other sources such as the accelerator control system or monitoring system. In order to have a general system these modules must be able to communicate with each other and perhaps with a host computer or a group of controlling computers. A very general communications system is the bus system, used in computers, in which all devices are connected in parallel to a group of lines, typically 50 to 100. By means of a protocol of communication on some of these lines, a device that wants to control the bus makes its wishes known. If the device is the highest priority one currently asking for the bus, it gains bus mastership and then signals another device that it wants to communicate with by means of a set of address lines. This system works very well in a computer that includes a processor, memory, and peripheral devices; its disadvantage is that only one device can be bus master at a time and only one communication can take place at a time. The proposed solution to this problem is to segment the bus so that each segment can operate independently without interfering with another one. This allows a large amount of parallel operation. It is, of course, necessary for one segment to communicate with other ones at some point in the process, and this is achieved by a device called the segment interconnect (SI). Much of the character of the system will be determined by the details of the SI. One possibility is a device that passes information only when the address falls within a band of values (or perhaps several bands); details of its specification are being worked on now.

Leipuner, L.

1978-01-01

116

Updatable Queue Protocol Based On TCP For Virtual Reality Environment  

E-print Network

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

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

2011-01-01

117

45 CFR 1310.17 - Driver and bus monitor training.  

Code of Federal Regulations, 2012 CFR

...Driver and bus monitor training. 1310.17 Section 1310.17 Public Welfare Regulations Relating to Public Welfare (Continued...DEPARTMENT OF HEALTH AND HUMAN SERVICES...and bus monitor training. (a) Each... (4) handle emergency situations,...

2012-10-01

118

45 CFR 1310.17 - Driver and bus monitor training.  

Code of Federal Regulations, 2013 CFR

...Driver and bus monitor training. 1310.17 Section 1310.17 Public Welfare Regulations Relating to Public Welfare (Continued...DEPARTMENT OF HEALTH AND HUMAN SERVICES...and bus monitor training. (a) Each... (4) handle emergency situations,...

2013-10-01

119

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

120

Research on 1Wire Bus Temperature Monitoring System  

Microsoft Academic Search

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

Wang Jingzhuo; Gong Chenglong

2007-01-01

121

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

122

Bus Lane with Intermittent Priority (BLIMP) Concept Simulation Analysis  

Microsoft Academic Search

This report discusses the results of a preliminary implementation study to determine the potential impacts of a new and innovative transit priority treatment along a BRT corridor in Eugene, Oregon. The bus lane with intermittent priority (BLIMP) utilizes dynamic lane assignment to designate an exclusive bus lane on a temporary, bus-actuated basis. The temporary lane is designated via overhead variable

Graham Carey; Thomas Bauer; Karen Giese

2009-01-01

123

Mitigating power bus noise with embedded capacitance in PCB designs  

Microsoft Academic Search

This paper investigates the power bus noise and power bus impedance of printed circuit boards with four different kinds of embedded capacitance. These boards have power-ground plane pairs separated by a very thin layer of material with high dielectric permittivity. It is shown that embedded capacitance effectively reduces power bus noise over the entire frequency range evaluated (up to 5

Minjia Xu; Todd H. Hubing; Juan Chen; James L. Drewniak; Thomas P. Van Doren; Richard E. DuBroff

2001-01-01

124

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

125

Increasing available FIFO space to prevent 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 an interrupt. An interrupt handler may stop the DMA and swap all descriptors from the full messaging queue into a larger queue (or enlarge the original queue). The interrupt handler then restarts the DMA. Alternatively, the interrupt handler stops the DMA, allocates a memory block to hold queue data, and then moves descriptors from the full messaging queue into the allocated memory block. The interrupt handler then restarts the DMA. During a normal messaging advance cycle, a messaging manager attempts to inject the descriptors in the memory block into other messaging queues until the descriptors have all been processed.

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

2012-02-07

126

Tel Aviv: Bus Stop on Allenby Street  

Microsoft Academic Search

Allenby Street is a main commercial street in Tel Aviv. It is also a main route on the city bus system. At night, Allenby Street is a destination for nightlife, while during the day it is a busy area for retail shopping. Alleby Street is known for it’s inexpensive shops and adult oriented clubs.

Chet Smolski

1980-01-01

127

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

128

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...

129

Creating a Wider Bus Using Caching Techniques  

Microsoft Academic Search

The effective bandwidth of a bus and external communicationports can be increased by using a variantof data compression techniques that compacts wordsinstead of data streams. The compaction is performedby caching the high order bits into a table and sendingthe index into the table along with the low order bits.A coherent table at the receiving end expands the wordinto it original

Daniel Citron; Larry Rudolph

1995-01-01

130

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

131

Longest-queue-first scheduling under SINR interference model  

E-print Network

We investigate the performance of longest-queue-first (LQF) scheduling (i.e., greedy maximal scheduling) for wireless networks under the SINR interference model. This interference model takes network geometry and the ...

Le, Long Bao

132

ANALYSIS OF A TWO-QUEUE MODEL WITH BERNOULLI SCHEDULES  

E-print Network

by Keilson and Servi 13]. The busy period of the M=G=1 vacation queue with Bernoulli sched- ules was studied service discipline. The 1-limited service discipline without walk time was solved by Cohen and Boxma 1

Lee, Duan-Shin

133

Control of queues with MAP servers: experimental results  

E-print Network

time (waiting time + service time) in this work. As results we report some surprising optimal policies server selection. We focus on the analysis of M/MAP(k)/n queues, where customers arrive to a queuing

Telek, Miklós

134

Behavior of queues at signalized intersections in heavy traffic  

NASA Technical Reports Server (NTRS)

This paper derives the asymptotic behavior of traffic queues at signalized intersections when the excess of departure capacity over arrivals approaches zero from above. The most interesting result is that the distribution of queue length approaches a negative exponential, with fewer restrictive assumptions than hitherto known. The main improvement results from more precise use of a combinatorial lemma of Spitzer, giving the maximum of the partial sums of a sequence of independent identically distributed random variables, plus some specific constructive probability calculations, many of them involving the Fourier transform. New results are presented on the probability that the queue be below a fixed bound and/or on the probability that the queue be empty. Applications to on-line estimators for real-time traffic control are suggested.

Posner, E. C.; Rodemich, E. R.

1976-01-01

135

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

136

Evaluation of concurrent priority queue algorithms. Technical report  

SciTech Connect

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

Huang, Q.

1991-02-01

137

Exclusive Queueing Processes and their Application to Traffic Systems  

E-print Network

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

Arita, C

2014-01-01

138

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

139

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 and Motivation Simple Jackson queueing networks, at equilibrium, are well known to have product-form solution

Taaffe, Michael R.

140

Simulation Model of Bus Rapid Transit  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

141

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

142

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

143

A scalable low power issue queue for large instruction window processors  

Microsoft Academic Search

Large instruction windows and issue queues are key to ex- ploiting greater instruction level parallelism in out-of-order superscalar processors. However, the cycle time and energy consumption of conventional large monolithic issue queues are high. Previous eorts to reduce cycle time segment the issue queue and pipeline wakeup. Unfortunately, this results in significant IPC loss. Other proposals which address en- ergy

Rajesh Vivekanandham; Bharadwaj Amrutur; R. Govindarajan

2006-01-01

144

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

E-print Network

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

Gerald Paul

2006-06-26

145

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

NASA Astrophysics Data System (ADS)

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

Wu, Xiaoyong; Ke, Xiaowu

2007-03-01

146

Research on a Queue Scheduling Algorithm in Wireless Communications Network  

NASA Astrophysics Data System (ADS)

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

Yang, Wenchuan; Hu, Yuanmei; Zhou, Qiancai

147

Parallel discrete-event simulation of FCFS stochastic queueing networks  

NASA Technical Reports Server (NTRS)

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

Nicol, David M.

1988-01-01

148

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

149

Reliable Fiber Sensor System with Star-Ring-Bus Architecture  

PubMed Central

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

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

2010-01-01

150

Research on service bus of network-centric simulation  

NASA Astrophysics Data System (ADS)

When high level architecture is used to build complex systems in support of modeling and simulation, the problems are low level of interoperability and poor reusage. Based on the concept of service-oriented and distributed technologies, a service bus of network-centric simulation is proposed. Definite the concept of community of service and service bus, establish the architecture of simulation service bus and its implementation framework, analyze three key technologies of its implementation process. The primary research and practice show that: the proposed simulation service bus can support to run community simulation tasks based on Internet and provide a reference for building a service-oriented environment of network centric simulation.

Zhang, Rui; Mao, Shao-Jie; Zhang, Hong-Jun; Zhang, You-Liang; Zhu, Yu

2013-03-01

151

Substation bus arrangement performance analysis program and metrics.  

E-print Network

??During preliminary substation design, only minimal information is available to the designer. Substation bus arrangements have been defined in textbooks for their advantages and disadvantages.… (more)

Oneal, Trevor Martin

2011-01-01

152

Finding an Individual Optimal Threshold of Queue Length in Hybrid Overlay/Underlay Spectrum Access in Cognitive Radio Networks  

NASA Astrophysics Data System (ADS)

In this paper, a hybrid overlay/underlay cognitive radio system is modeled as an M/M/1 queue where the rate of arrival and the service capacity are subject to Poisson alternations. Each packet as a customer arriving at the queue makes a decision to join the queue or not. Upon arrival, the individual decision of each packet is optimized based on his observation about the queue length and the state of system. It is shown that the individually optimal strategy for joining the queue is characterized by a threshold of queue length. Thus, the individual optimal threshold of queue length is analyzed in detail in this work.

Do, Cuong T.; Tran, Nguyen H.; Hong, Choong Seon; Lee, Sungwon

153

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

154

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

155

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Federal Transit Administration Over-the-Road Bus Accessibility Program Grants...FTA) Notice titled ``Over-the-Road Bus Accessibility Program Grants...the Special Warranty for the Over-the-Road Bus Accessibility Program that...

2010-04-16

156

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

E-print Network

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

Winiarz, Christine Eve

2007-01-01

157

49 CFR 605.18 - Comments by private school bus operators.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Comments by private school bus operators. 605.18 Section 605.18 ...TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.18 Comments by...

2012-10-01

158

49 CFR 605.18 - Comments by private school bus operators.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Comments by private school bus operators. 605.18 Section 605.18 ...TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.18 Comments by...

2013-10-01

159

Application of CAN-bus Network in Intelligent parking  

NASA Astrophysics Data System (ADS)

Convenient life makes intelligent parking every- where. This paper describes how to connect the various separate modern terminal of intelligent parking with CAN-bus network, and the competitive advantage of the system by using the CAN-bus network. From a technical point of view, this paper describes the development trend of intelligent parking in next few years.

Jianjun, WU; Juan, Hu

160

Safety evaluation of a PEMFC bus Lionel PERRETTE1  

E-print Network

Technical specifications The proposed vehicle is a twelve meter articulated bus (see figure 1 below there is no specific regulation for fuel cell vehicles approval neither under the French automotive regulation nor). It results from the combination of a trolley bus (external electrical power supply) and a fuel cell system

Paris-Sud XI, Université de

161

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

162

Research of automatic bus transfer in substation with DG connected  

Microsoft Academic Search

With rapid increase in the application of distributed generation, the action time delay of automatic bus transfer will be longer in radially fed networks. It is not conducive to the fast input of automatic bus transfer. In this paper, take the distributed generation in included in the 110kV terminal substation of distribution network which is fed by a single source,

Lei Wang; Ming Sun

2010-01-01

163

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

164

Battery management system for series-hybrid electric shuttle bus  

Microsoft Academic Search

In this paper, a battery management system (BMS) of a lead-acid battery pack for a series hybrid electric vehicle (SHEV) shuttle bus is presented. The BMS is a necessary component for an optimal operation of power-train in the SHE V shuttle bus including for timely detection of an abnormal condition during charging and discharging the battery pack. The presented BMS

Teerayut Piboonrujananon; Nisai H. Fuengwarodsakul

2011-01-01

165

Integrated Gate and Bus Assignment at Amsterdam Airport Schiphol  

E-print Network

], we have presented a column generation algorithm to create an assignment for aircraft to gates,marjan,slam}@cs.uu.nl Extended abstract Abstract. At an airport a series of assignment problems need to be solved before aircraft which aircraft) and the bus assignment problem (i.e. which bus will transport which passen- gers

Utrecht, Universiteit

166

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

167

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

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

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

168

M.Sc.inICTInBusIness ICT in Business  

E-print Network

M.Sc.inICTInBusIness M.Sc. in ICT in Business Dr. Michel R.V. Chaudron Program Director ICT in Business M.Sc. programme information session 23 Nov 2010 #12;M.Sc.inICTInBusIness ICT Means Business... Economies of Speed and Scale ICT is enabling exchange of information at unprecedented scale and speed

Emmerich, Michael

169

Design and implementation of an efficient priority queue  

Microsoft Academic Search

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

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

1976-01-01

170

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

171

KalmanQueue: An Adaptive Approach to Virtual Queuing  

E-print Network

Pass is a virtual queuing system that allows some theme park customers to significantly cut down their waiting timeKalmanQueue: An Adaptive Approach to Virtual Queuing February 10, 2004 Abstract Quick are not significantly affected and (2) maximum waiting time for QuickPass users is small. To build a solid foundation

Morrow, James A.

172

ON PERFORMANCE EVALUATION AND OPTIMIZATION PROBLEMS IN QUEUES WITH RESEQUENCING  

E-print Network

Abstract Studies of queuing models with resequencing of jobs to keep the order at the output in the order, distributed database systems, production flow-networks, in information networks and other multi-server queuing of the servers (if any) is named primary buffer (PB). The waiting times and the queue lengths in the PB and RSB

Stanchev, Peter

173

The Price of Anarchy in the Markovian Single Server Queue  

E-print Network

this phenomena assuming a simple M/M/1 observable queue with linear waiting costs and a fixed service value. Surprisingly, there has been little research on quantifying the inefficiency of queuing systems. Haviv, exponential service, linear waiting costs and fixed rewards from obtaining service. Balking is associated

Hassin, Refael

174

Assignment 2, Single Queues Due date Oct. 10  

E-print Network

of queuing model would you use? M/M/m queue (3) Find the expected length of time the packet spends waiting waiting time of a job? #12;Question 2: Consider an optical switch that is connected with a fiber optic in such a queuing system? Channels, buffer, system Capacity, size, arrival and departure time (2) What type

Shihada, Basem

175

Computational algorithms for closed queueing networks with exponential servers  

Microsoft Academic Search

Methods are presented for computing the equilibrium distribution of customers in closed queueing networks with exponential servers. Expressions for various marginal distributions are also derived. The computational algorithms are based on two-dimensional iterative techniques which are highly efficient and quite simple to implement. Implementation considerations such as storage allocation strategies and order of evaluation are examined in some detail.

Jeffrey P. Buzen

1973-01-01

176

Single-Server Queues with Spatially Distributed Arrivals  

E-print Network

Single-Server Queues with Spatially Distributed Arrivals Dirk P. Kroese Department of Applied on the circle, according to a uniform distribution, they wait for a single server who travels on the circle. The server's movement is modelled by a Brownian motion with drift. Whenever the server encounters a customer

Kroese, Dirk P.

177

Performance bounds for queueing networks and scheduling policies  

Microsoft Academic Search

Except for the class of queueing networks and scheduling policies admitting a product form solution for the steady-state distribution, little is known about the performance of such systems. For example, if the priority of a part depends on its class (e.g., the buffer that the part is located in), then there are no existing results on performance, or even stability.

Sunil Kumar; P. R. Kumar

1994-01-01

178

Parallel Priority Queues Maria Cristina PINOTTIy and Geppino PUCCIz  

E-print Network

Parallel Priority Queues Maria Cristina PINOTTIy and Geppino PUCCIz Abstract This paper introduces-H) and the n-Bandwidth- Leftist-Heap (n-L), that are obtained as extensions of the well known sequential binary structures, the n-Bandwidth-Heap (n-H), for unmeldable PPQs, and the n-Bandwidth-Leftist-Heap (n-L

Pucci, Geppino

179

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

180

A Model for the Bus System in Cuernevaca (Mexico)  

E-print Network

The bus transportation system in Cuernevaca, Mexico, has certain distinguished, innovative features and has been the subject of an intriguing, recent study by M. Krbalek and P. Seba. Krbalek and Seba analyzed the statistics of bus arrivals on Line 4 close to the city center. They studied, in particular, the bus spacing distribution and also the bus number variance measuring the fluctuations of the total number of buses arriving at a fixed location during a time interval T. Quite remarkably, it was found that these two statistics are well modeled by the Gaussian Unitary Ensemble (GUE) of random matrix theory. Our goal in this paper is to provide a plausible explanation of these observations, and to this end we introduce a microscopic model for the bus line that leads simply and directly to GUE.

Jinho Baik; Alexei Borodin; Percy Deift; Toufic Suidan

2005-10-19

181

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.

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

2015-01-01

182

Accurate Power Loss Model Derivation of a High-Current Dual Active Bridge Converter for an Automotive Application  

Microsoft Academic Search

An accurate power loss model for a high-efficiency dual active bridge converter, which provides a bidirectional electrical interface between a 12-V battery and a high-voltage (HV) dc bus in a fuel cell car, is derived. The nominal power is 2 kW, the HV dc bus varies between 240 and 450 V, and the battery voltage range is between 11 and

Florian Krismer; Johann W. Kolar

2010-01-01

183

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

184

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

185

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

186

Development of VRLA battery for hybrid bus  

NASA Astrophysics Data System (ADS)

Valve regulated lead-acid (VRLA) batteries named SEH65 series for hybrid vehicles have long been used in hybrid inverter-controlled motor and retarder system (HIMR) buses developed by Hino Motors Ltd. In order to elucidate the points for improving the battery performance, the battery performance, which were obtained during field use and by bench test, was analyzed in details. As the result, a new VRLA battery, with which longer life performance can be expected, has been developed by improving the positive grid corrosion resistance and adopting a new additive for the negative plates. In addition, it was found that estimation of residual life of the battery is possible by measuring the battery voltage in high-rate discharging during bus use and by adjusting it with the field use conditions.

Nakayama, Yasuhide; Hojo, Eiji; Koike, Tetsuo

187

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

188

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

189

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

190

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

191

Design tradeoffs in stall-control circuits for 600 MHz instruction queues  

Microsoft Academic Search

A 600 MHz superscalar Alpha microprocessor contains separate integer and floating-point issue units. The integer issue unit selects up to four data-ready instructions to issue out of a 20-entry queue. The floating-point issue unit, similarly, selects two instructions out of a separate 15-entry queue. Though their operation is similar, the two queues required different tradeoffs to meet design goals. This

T. Fischer; D. Leibholz

1998-01-01

192

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

E-print Network

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

Bertini, Robert L.

193

A VHDL-based bus model for multi-PCB system design  

Microsoft Academic Search

In the development of bus-based systems and individual PCB boards interfacing to a bus, the simulation usually re- quires a specific test bench or creation of quite complex stimuli. This problem can be avoided with a VHDL model of the bus. In this paper, the bus model concept is discussed. The concept can be applied to serial and parallel, single

Jari Toivanen; Jari Honkola; Jari Nurmi; Jyrki Tuominen

1994-01-01

194

An Automated Dual-Wavelength Spectrophotometer Optimized for Phytochrome Assay  

Microsoft Academic Search

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

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

1984-01-01

195

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

196

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

197

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

198

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

199

Distributed shared memory multiprocessors using multistage bus networks  

E-print Network

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

Iyer, Ravishankar

1996-01-01

200

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

201

Updatingga Tradition The NewYellowShuttleBus  

E-print Network

can be manufactured with several drivetrains, including, but not limited to, compressed natural gas bus prototype with a natural gas powertrain. This prototype will have added amenities to support, liquid natural gas, propane and bio-diesel. #12;

Kyte, Michael

202

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

203

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

204

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

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

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

205

A Statistics-based Framework for Bus Travel Time Prediction.  

E-print Network

??In this paper, we develop a statistics-based bus travel time prediction framework, called Historical Trajectorybased Travel/Arrival Time Prediction (HTTP) for real-time prediction of travel time… (more)

Si, Weiping

2012-01-01

206

The key technologies of a distributed temperature monitoring system based on 1Wire bus  

Microsoft Academic Search

This paper focuses on improving the quality performance of 1-Wire bus which is mostly necessary to practice application. The key technology about 1-Wire bus that applies to DS18B20 and other 1-Wire bus serious manufactures is introduced in detail. The numbers of sensors hanging on 1-Wire bus are received according to the data bus driving ability and communication distance produced by

Chengliang Zhang; Xianying Feng; Lei Li

2010-01-01

207

Queueing models for token and slotted ring networks. Thesis  

NASA Technical Reports Server (NTRS)

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

Peden, Jeffery H.

1990-01-01

208

Solid state power bus controllers for aerospace applications  

E-print Network

SOLID STATE POWER BUS CONTROLLERS FOR AEROSPACE APPLICATIONS A Thesis by TERRY JOSEPH VILLARREAL Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE December 1988 Major Subject: Electrical Eny'neering SOLID STATE POWER BUS CONTROLLERS FOR AEROSPACE APPLICATIONS A Thesis TERRY JOSEPH VILLARREAL Approved as to style and content by: Mehrdad Ehsani (Chairman of Committee) Robert D. Nevels...

Villarreal, Terry Joseph

1988-01-01

209

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

210

Compressed natural gas bus safety: a quantitative risk assessment.  

PubMed

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

Chamberlain, Samuel; Modarres, Mohammad

2005-04-01

211

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

212

Dynamic fluid-based scheduling in a multi-class abandonment queue M. Larra~naga2,5  

E-print Network

Dynamic fluid-based scheduling in a multi-class abandonment queue M. Larra~naga2,5 , U. Ayesta2 classes of customers in the presence of abandonments. We consider two different models: (1) customers can abandon both while waiting in the queue and while being served, (2) only customers that are in the queue

Ayesta, Urtzi

213

References 36 [LOY62] R. M. Loynes, ``The stability of a queue with nonindependent interarrival and service  

E-print Network

time probabilities in an M/G/1 queue with long­tailed service time,'' Queueing Systems, vol. 10, pp and the markov­modulated M/G/1 queue,'' Stochastic Processes and their Applications, vol. 37, pp. 313--326, 1991. (Series A), vol. 43, pp. 347--365, 1987. [COH73] J. W. Cohen, ``Some results on regular variation

Jelenkovic, Predrag

214

Volume 2, Number 5 OPERATIONS RESEARCH LETTERS December 1983 COMPARISON CONJECTURES ABOUT THE M/G/s QUEUE  

E-print Network

conjecture that the equilibrium waiting-time distribution in an M/O/s queue increases stochastically when property for the case of many servers in light traffic. Queues, multi-server queues, waiting time, stochastic comparisons, light traffic I. Introduction In this paper we pose some important queuing problems

Whitt, Ward

215

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

E-print Network

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

Begin, Thomas

216

EFFICIENCY-DRIVEN HEAVY-TRAFFIC APPROXIMATIONS FOR MANY-SERVER QUEUES WITH ABANDONMENTS  

E-print Network

EFFICIENCY-DRIVEN HEAVY-TRAFFIC APPROXIMATIONS FOR MANY-SERVER QUEUES WITH ABANDONMENTS by Ward-driven (ED) limiting regime for many-server queues with abandonments. The starting point is the realization that, in the presence of substantial customer abandonment, call-center service- level agreements (SLA

Whitt, Ward

217

THE IMPACT OF DELAY ANNOUNCEMENTS IN MANY-SERVER QUEUES WITH ABANDONMENT  

E-print Network

THE IMPACT OF DELAY ANNOUNCEMENTS IN MANY-SERVER QUEUES WITH ABANDONMENT: SUPPLEMENTARY MATERIAL with customer abandonment. We assume that the queue is not visible to waiting customers, as in most customer immediately upon arrival, customers may balk or have new abandonment behavior as a function of the announced

Shimkin, Nahum

218

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

E-print Network

The cµ/ rule for many-server queues with abandonment Rami Atar Chanit Giat Nahum Shimkin Department consider a multi-class queueing system with multiple homogeneous servers and customer abandonment. For each customer class i, the holding cost per unit time, the service rate and the abandonment rate are denoted

Atar, Rami

219

EFFICIENCY-DRIVEN HEAVY-TRAFFIC APPROXIMATIONS FOR MANY-SERVER QUEUES WITH ABANDONMENTS  

E-print Network

EFFICIENCY-DRIVEN HEAVY-TRAFFIC APPROXIMATIONS FOR MANY-SERVER QUEUES WITH ABANDONMENTS by Ward the efficiency-driven (ED) many-server heavy-traffic limiting regime for queues with abandonments. Attention extra waiting spaces, exponential abandon times (the final +M) and the first-come first-served service

Whitt, Ward

220

An Analysis of Double Queue on PRT System and a Control Strategy for Merging  

Microsoft Academic Search

This paper deals with a merging section of Personal Rapid Transit system. Several schemes have been proposed for the control of vehicles in PRT systems. In quasi-synchronous control systems, one flow of traffic must form a queue at a merging section in order to avoid the collision of vehicles. In other words, a queue is formed on one of the

Cao Kai; Ryuta Matsuda; Youhei Yano; Yoshio Hamamatsu

2005-01-01

221

THE INFLUENCE OF DEMAND VARIABILITY ON THE PERFORMANCE OF A MAKE-TO-STOCK QUEUE  

E-print Network

1 THE INFLUENCE OF DEMAND VARIABILITY ON THE PERFORMANCE OF A MAKE-TO-STOCK QUEUE Zied Jemaï : 10.1016/j.ejor.2003.06.042 #12;2 The Influence of Demand Variability on the Performance of a Make-to-Stock variability in capacitated production settings, we analyse a make-to-stock queue with general demand arrival

Paris-Sud XI, Université de

222

Empirical Evaluation of a Queueing Network Model for Semiconductor Wafer Fabrication  

Microsoft Academic Search

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

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

1988-01-01

223

Busy Period of a Delayed-Service Single-Server Poisson Queue  

NASA Astrophysics Data System (ADS)

In this paper we investigate busy period of a single-server Poisson queue with delayed-service. We will analyze this model by considering M/G/1 approximating a non-Markovian system. We obtain the distribution of the length of a busy period. Additionally, steady-state mean and distribution of the queue length will be obtained.

Haghighi, A. M.; Mishev, D. P.; Chukova, S. S.

2007-10-01

224

Volume I, Number $ OPERATIONS RESEARCH LETTERS November 1982 REFINING DIFFUSION APPROXIMATIONS FOR QUEUES  

E-print Network

for queues. Diffusion approximations are developed in several different ways for the mean waiting time approximations and associated heavy-traffic Emit theorems have now become basic tools of queuing theory; e for the expected waiting time in the standard GI/G/I queue. In the GI/G/I model there is a single server, unlimited

Whitt, Ward

225

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

E-print Network

on queuing systems has been thoroughly stud- ied from the delay distribution perspective. However in the queue is very important to people, perhaps not less than the wait itself. In fact, our own observation is that perhaps the major reason for using a queue at all is the wish to provide fair service and fair waiting

Levy, Hanoch

226

Analysis of a single-server queue interacting with a fluid reservoir  

E-print Network

Analysis of a single-server queue interacting with a fluid reservoir I.J.B.F. Adan , E.A. van Doorn reservoir is empty or not. Con- versely, the rate of change of the content of the reservoir is determined by the state of the queueing system, since the reservoir fills during idle periods and depletes during busy

Al Hanbali, Ahmad

227

Real Time Queue Length Estimation for Signalized Intersections Using Travel Times from Mobile Sensors  

E-print Network

, the queuing delays reduce linearly within a cycle. The delay pattern can be estimated by a linear fitting1 Real Time Queue Length Estimation for Signalized Intersections Using Travel Times from Mobile Research Part C January, 2011 #12;2 ABSTRACT We study how to estimate real time queue lengths

Ban, Xuegang "Jeff"

228

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

Microsoft Academic Search

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

Sally Floyd; Ramakrishna Gummadi; Scott Shenker

2001-01-01

229

Queueing Systems with Hard Delay Constraints: A Framework for Real-Time Communication over Unreliable Wireless  

E-print Network

Queueing Systems with Hard Delay Constraints: A Framework for Real-Time Communication over clients that generate real-time flows. From a queue- ing systems perspective, these problems can, and the throughput requirements of clients. We then determine the necessary and sufficient condition for feasibility

230

On the M X =G=1 Queue with a Waiting Server and Vacations  

E-print Network

On the M X =G=1 Queue with a Waiting Server and Vacations Uri Yechiali Department of Statistics@post.tau.ac.il] Abstract We analyze the M X =G=1 queue with server vacations and an additional feature, re ecting various real-life situations, in which the server, upon #12;nding an empty system at the end of a vacation

Yechiali, Uri

231

A Single Server Retrial Queue with Different Types of Server Interruptions  

E-print Network

A Single Server Retrial Queue with Different Types of Server Interruptions Tewfik Kernane@gmail.com February 11, 2009 Abstract We consider a single server retrial queue with the server subject to interruptions and classical retrial policy for the access from the orbit to the server. We analyze

Paris-Sud XI, Université de

232

Batch queues with choice of arrivals: Equilibrium analysis and experimental study  

Microsoft Academic Search

We study the decisions agents make in two queueing games with endogenously determined arrivals and batch service. In both games, agents are asked to independently decide when to join a queue, or they may simply choose not to join it at all. The symmetric mixed-strategy equilibrium of two games in discrete time where balking is prohibited and where it is

William E. Stein; Amnon Rapoport; Darryl A. Seale; Hongtao Zhang; Rami Zwick

2007-01-01

233

Solution for A Retrial Queueing Problem in Cellular Networks with the Fractional Guard Channel Policy  

E-print Network

Solution for A Retrial Queueing Problem in Cellular Networks with the Fractional Guard Channel introduce a retrial queueing problem for wireless cellular networks ap- plying the Fractional Guard Channel because of the ongoing call disruption problem. The guard channel policy [8] is the well- known technique

Do, Tien Van

234

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

SciTech Connect

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

Laughlin, M.

2004-04-01

235

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

236

Stationary Waiting-Time Distributions for Single-Server Queues  

Microsoft Academic Search

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

R. M. Loynes

1962-01-01

237

Queueing Behavior over a Gilbert-Elliott Packet Erasure Channel  

E-print Network

-sensitive systems. The packet-erasure channel model and the Baum-Welch algorithm used to estimate system parameters are introduced in Section 3. The M/G/1-like Markov system and its matrix geometric solution are studied 4 in Section 4. In Section 5, we develop... channel state at the same instant is represented by . One can show that the aggregate process forms a Markov chain. More precisely, the evolution of our discrete-time system is akin to an M/G/1 queue. There are many established...

Cai, Yi

2012-02-14

238

The Robo-AO automated intelligent queue system  

NASA Astrophysics Data System (ADS)

Robo-AO is the first automated laser adaptive optics instrument. In just its second year of scientific operations, it has completed the largest adaptive optics surveys to date, each comprising thousands of targets. Robo-AO uses a fully automated queue scheduling system that selects targets based on criteria entered on a per observing program or per target basis, and includes the ability to coordinate with US Strategic Command automatically to avoid lasing space assets. This enables Robo-AO to select among thousands of targets at a time, and achieve an average observation rate of approximately 20 targets per hour.

Riddle, Reed L.; Hogstrom, Kristina; Papadopoulos, Athanasios; Baranec, Christoph; Law, Nicholas M.

2014-07-01

239

Physics on the Bus—How About Physics on Your Bus?  

NASA Astrophysics Data System (ADS)

Riders on the buses of UMass Transit (here in the "Five-College" area) and of the University of Georgia transit system have something other than the usual "Please don't eat on the bus" placards to read—simple physics questions in the overhead advertising racks, with appealing cats and dogs posing questions, giving partial answers (some flat-out wrong, some partially correct), ending up with "What do you think? … Visit our website." One sample is given below; others can be viewed at http://www.amherst.edu/˜physicsqanda. (More often than not, the dog gets it wrong; I'm a cat person.) This project was begun in collaboration with John King and was inspired by one of the many ideas described in his 2000 Oersted Medal address.

Romer, Robert H.

2004-12-01

240

Quantum bus of metal nanoring with surface plasmon polaritons  

SciTech Connect

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

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

2010-12-15

241

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

242

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

243

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

244

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

245

Invasion percolation on a tree and queueing models  

NASA Astrophysics Data System (ADS)

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

Gabrielli, A.; Caldarelli, G.

2009-04-01

246

Invasion percolation on a tree and queueing models.  

PubMed

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

Gabrielli, A; Caldarelli, G

2009-04-01

247

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

248

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

NASA Astrophysics Data System (ADS)

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

249

CAN(Controller Area Network) Bus Communication System Based on Matlab\\/Simulink  

Microsoft Academic Search

CAN bus communication system was established mainly using SimEvents module in the software of Matlab\\/Simulink. Performance indexes of CAN bus system, which embraces worst-case response time of messages and bus load, were separately gained by theoretical calculation, experiments in Matlab and CANoe. The calculation and experiment results were compared sufficiently, and it concludes that CAN bus system established in Matlab\\/Simulink

Fang Li; Lifang Wang; Chenglin Liao

2008-01-01

250

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

Microsoft Academic Search

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

Richard A. Hargis; Tim Jur

2008-01-01

251

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

252

Intelligent node of 1553B bus based on Gigabit Ethernet protocol  

Microsoft Academic Search

1553B bus node needs to be converted for the data transfer of other buses. Gigabit Ethernet is built on the Ethernet standard technology. It has the advantages of fast communications, strong adaptability, so it can serve as a 1553B bus data transmission channel. The 1553B bus protocol is introduced and analyzed, including data link layer, physical layer, and functional analysis.

An Peng

2010-01-01

253

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

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Main-emergency bus-tie. 112.05-3 Section 112.05-3 Shipping ...SYSTEMS General § 112.05-3 Main-emergency bus-tie. Each bus-tie between a main switchboard and an emergency...

2011-10-01

254

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

Code of Federal Regulations, 2010 CFR

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

2010-10-01

255

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

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Main-emergency bus-tie. 112.05-3 Section 112.05-3 Shipping ...SYSTEMS General § 112.05-3 Main-emergency bus-tie. Each bus-tie between a main switchboard and an emergency...

2013-10-01

256

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

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Main-emergency bus-tie. 112.05-3 Section 112.05-3 Shipping ...SYSTEMS General § 112.05-3 Main-emergency bus-tie. Each bus-tie between a main switchboard and an emergency...

2014-10-01

257

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

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Main-emergency bus-tie. 112.05-3 Section 112.05-3 Shipping ...SYSTEMS General § 112.05-3 Main-emergency bus-tie. Each bus-tie between a main switchboard and an emergency...

2012-10-01

258

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

Microsoft Academic Search

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

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

2005-01-01

259

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

Microsoft Academic Search

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

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

2004-01-01

260

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

ERIC Educational Resources Information Center

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

Fox, Michael

1995-01-01

261

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

SciTech Connect

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

Not Available

2011-01-01

262

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

263

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.

264

Design of City-Bus Intelligent Control System Framework  

Microsoft Academic Search

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

Jian Hu; Gangyan Li

2006-01-01

265

Power Electric Aiding Controller for Automated Bus Stopping  

E-print Network

Power Electric Aiding Controller for Automated Bus Stopping Jorge Godoy, Vicente Milanés, Joshue Pérez, Jorge Villagrá and Carlos González AUTOPIA program, Centre for Automation and Robotics, UPM for improving urban mobility where the public transport is the main key. To present day, solutions as special

Paris-Sud XI, Université de

266

Power bus decoupling on multilayer printed circuit boards  

Microsoft Academic Search

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

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

1995-01-01

267

Safety Management Evaluation in Bus and Coach Companies  

Microsoft Academic Search

In recent years, different initiatives have been carried out to develop Safety Management System guides or standards for coach and bus companies. They all consist of a set of safety and management requirements to be followed by organizations. However, none of them offers a complete set of tools to evaluate the safety level of the company and find the main

Francisco Aparicio Izquierdo; Yago Colodrón Sesemann; Juan Ángel Terrón Alonso

2009-01-01

268

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

269

Hybrid genetic algorithms for scheduling bus and train drivers  

Microsoft Academic Search

Introduces the subject of bus- and train-driver scheduling, and outlines a standard successful approach (TRACS II) using a blend of heuristics and integer linear programming. We discuss a few limitations of this system; in order to overcome these, we have investigated a range of metaheuristics and constraint programming approaches, and some of these are outlined. Finally, we present a hybrid

Raymond S. K. Kwan; Anthony Wren; Ann S K Kwan

2000-01-01

270

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.

271

Get on the digital bus to substation automation  

Microsoft Academic Search

This paper presents next-generation measuring systems with a real-time Ethernet process bus. Digital communication has proven its advantages in high voltage substations from bay control and protection up to the telecommunication interface. The enlarged digital area in substations offers wide ranges and easy adjustment of parameters for in improved fitness of the investment for future demands.

Martin Schumacher; Clemens Hoga; Joachim Schmid

2007-01-01

272

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

273

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

274

Compressed Natural Gas Bus Safety: A Quantitative Risk Assessment  

Microsoft Academic Search

This study assesses the fire safety risks associated with compressed natural gas (CNG) vehicle systems, comprising primarily a typical school bus and supporting fuel infrastructure. The study determines the sensitivity of the results to variations in component failure rates and consequences of fire events. The components and subsystems that contribute most to fire safety risk are determined. Finally, the results

Samuel Chamberlain; Mohammad Modarres

2005-01-01

275

Finite element modal analysis for a light bus  

Microsoft Academic Search

The finite element model of a light bus body is established. The vibration modalities are evaluated using finite element software. The simulated results are compared with test date. It shows that the model has represented the vibration characteristics of the original structure. The finite element model for the acoustic cavity is established. The first step modality in the longitudinal direction

Wen-ku Shi; Zhi-yong Chen; Fu-xiang Guo; Zhi-hong Shen

2009-01-01

276

Manufacturing of Board Level Waveguide Bus Using Hard Mold  

E-print Network

Manufacturing of Board Level Waveguide Bus Using Hard Mold Xiaohui Lin1 , Xinyuan Dou1 , Amir fabricated on flexible substrate using nickel hard mold. Optical out-of-plane loss test and high speed data, 4]. In this work, we present a low cost molding method has been applied to fabricate optical

Chen, Ray

277

Modelling and analysis of a commercial field bus protocol  

Microsoft Academic Search

We report on an industrial application ofUPPAAL, in which a commercial field bus protocol (AF100) is modelled and analysed using the tool. During the case study, a num- ber of imperfections in the protocol logic and its implemen- tation are found and their sources are debugged based on abstract models of the protocol; respective improvements have been suggested. In this

Alexandre David; Wang Yi

2000-01-01

278

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

279

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

280

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

281

Acyclic Traffic Management in FieldBus Scenarios  

Microsoft Academic Search

In process control enviroments, acyclic traffic management creates several problems as it is not possible to know the amount of traffic, and thus the bandwidth required, a priori. In this paper the authors deal with the problem of managing acyclic traffic, using some of the instruments provided by the FieldBus Data Link Layer protocol. Two scheduling policies are proposed and

S. Cavalieri; A. Di Stefano; O. Mirabella

1992-01-01

282

Multicycle Polling Scheduling Algorithms for FieldBus Networks  

Microsoft Academic Search

The paper deals with the scheduling of periodic information flow in a FieldBus environment. The scheduling problem is defined from an analytical point of view, giving a brief survey of the most well-known solutions. One of these is called multicycle polling scheduling, which is based on the hypothesis that all the production periods of the periodic processes to be scheduled

Salvatore Cavalieri; Salvatore Monforte; Angelo Corsaro; Giovanni Scapellato

2003-01-01

283

Static Bus Schedule aware Scratchpad Allocation in Multiprocessors  

E-print Network

, the external (off-chip) memory is accessed through a shared bus among all the available processors in the chip contention introduced by other PEs. Since the requests serviced from on-chip SPMs do not access the off-chip graphs. MPSoCs usually contain an on-chip scratchpad memory attached locally to each processing element

Roychoudhury, Abhik

284

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.

285

How to Cut Costs by Saving School Bus Fuel.  

ERIC Educational Resources Information Center

A program started in Washington County, Maryland in 1980 has been successful in saving school bus fuel and bringing down transportation costs incurred by its fleet of 200 buses. Driver training and motivation, as well as a partial transfer to diesel buses, are at the heart of the program. The drivers are taught five fuel saving techniques: cut…

Seiff, Hank

286

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

287

Verification of an Audio Protocol with Bus Collision Using UPPAAL  

Microsoft Academic Search

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

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

1996-01-01

288

Low back trouble among urban bus drivers in Denmark.  

PubMed

The occurrence of low back trouble and possible connection with psychosocial conditions among urban bus drivers were studied using a questionnaire and subsequent registration of hospital discharges. 2,045 (83%) full-time male bus drivers in the three largest cities in Denmark answered a questionnaire in 1978 regarding psychosocial factors and health. The prevalence of frequent low back pain was 57%. In a control group of 195 motormen the prevalence was 40%. Standardized Morbidity Ratio for bus drivers discharged from hospital during the period 1978-1984 with the diagnosis lumbar disc herniation was 137 compared to all Danish men. These differences were statistically significant. Of psychosocial factors only "the feeling of being mentally unbalanced" was found to be statistically significantly related to subsequent hospital discharge with a LBT-diagnosis. Long seniority as bus driver of those discharged from hospital with LBT makes it probable that LBT has etiologic factors in the work environment. The sedentary position and whole-body vibrations may be contributory causes. PMID:2526367

Netterstrøm, B; Juel, K

1989-01-01

289

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

290

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

291

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

292

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

293

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

PubMed Central

We describe a multicomponent intervention to improve bus-riding behavior of students attending an urban public school. The intervention was developed with technical assistance consultation that emphasized collaboration among students, school personnel, and bus drivers. The primary intervention procedures were identifying appropriate behaviors during transportation ("bus rules"), training bus drivers to deliver positive reinforcement, and rewarding student performance through a weekly school-based lottery. Disruptive bus behaviors, as measured by discipline referrals and suspensions, decreased with intervention relative to baseline phases in an ABAB reversal design. These positive results were maintained over the long term, with school personnel assuming responsibility for intervention in the absence of ongoing consultation. PMID:14768676

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

2003-01-01

294

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

295

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

2012-06-07

296

An Analysis of Double Queue on PRT System and a Control Strategy for Merging  

NASA Astrophysics Data System (ADS)

This paper deals with a merging section of Personal Rapid Transit system. Several schemes have been proposed for the control of vehicles in PRT systems. In quasi-synchronous control systems, one flow of traffic must form a queue at a merging section in order to avoid the collision of vehicles. In other words, a queue is formed on one of the lines, which is called the sub line; the other line is called the main line. Basically, vehicles on the main line have priority. We propose a control strategy whereby vehicles on the main line are usually not stopped; vehicles on the main line are only stopped when the number of waiting vehicles on the sub line exceeds some specific number. Therefore, queues are formed on the main line and the sub line, respectively. This paper presents a fundamental discussion of the effects of the double queue and the relationship between traffic density and the behavior of traffic.

Kai, Cao; Matsuda, Ryuta; Yano, Youhei; Hamamatsu, Yoshio

297

The net output process of a system with infinitely many queues  

E-print Network

process is a Poisson process. Keywords and phrases. Queuing networks. Zero range process. Burke's theorem of the customers is being served and the others are waiting for service. The service time of queue x â?? 0

298

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

299

Efficient Computation of Probabilities of Events Described by Order Statistics and Applications to Queue Inference  

E-print Network

This paper derives recursive algorithms for efficiently computing event probabilities related to order statistics and applies the results in a queue inferencing setting. Consider a set of N i.i.d. random variables in [0, ...

Jones, Lee K.

300

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

E-print Network

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

Schaack, Christian

301

State-dependent Importance Sampling for a Slow-down Tandem Queue  

E-print Network

in the downstream queue before exhausting the system, starting from any given state in the state space. Due is the the two-node system with server slow-down, also known as a system with backpressure. This mechanism

Boucherie, Richard J.

302

Melding priority queues Ran Mendelson # Robert E. Tarjan + Mikkel Thorup # Uri Zwick #  

E-print Network

Melding priority queues Ran Mendelson # Robert E. Tarjan + Mikkel Thorup # Uri Zwick # Abstract We log n) running time of an algorithm by Gabow, Galil, Spencer and Tarjan that works for arbitrary edge

Zwick, Uri

303

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

NASA Astrophysics Data System (ADS)

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

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

304

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

305

The Linearity of Low Frequency Traffic Flow: An Intrinsic I\\/O Property in Queueing Systems  

Microsoft Academic Search

Consider a class of queueing systems which can be modeled by a finite Quasi-Birth-Death(QBD) process. In this paper we develop a powerful computational technique for spectral analyses(i.e. second-order statistics) of output, queue and loss. Emphasis is placed on output powerspectrum and input-output coherence function in response to various input power spectral propertiesand system parameters. The coherence function is defined to

James D. Pruneski; San-qi Li

1995-01-01

306

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

307

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

308

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

309

Towards ubiquitous computing in Indonesia: automated bus system  

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

310

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

311

Memory Bandwidth Optimization for Wide-Bus Machines  

E-print Network

One of the critical problems facing designers of high performance processors is the disparity between processor speed and memory speed. This has occurred because innovation and technological improvements in processor design have outpaced advances in memory design. While not a panacea, some gains in memory performance can be had by simply increasing the width of the bus from the processor to memory. Indeed, high performance microprocessors with wide buses (i.e., capable of transferring 64 bits or more between the CPU and memory) are beginning to become commercially available (e.g. MIPS R4000, DEC Alpha, and Motorola 88110). This paper discusses some compiler optimizations that take advantage of the increased bandwidth available from a wide bus. We have found that very simple strategies can reduce the number of memory requests by 10 to 15 percent. For some data and compute intensive algorithms, more aggressive optimizations can yield significantly higher reductions. The paper describes t...

Michael Alexander Mark; Michael J. Alex; Michael J. Alexander; Postal Address; Professor Jack; W. Davidson; Michael A. Alexander; Mark W. Bailey; Mark W. Bailey; Mark W. Bailey; Bruce R. Childers; Bruce R. Childers; Bruce R. Childers; Jack W. Davidson; Jack W. Davidson; Jack W. Davidson; Sanjay Jinturkar; Sanjay Jinturkar; Sanjay Jinturkar

1993-01-01

312

Memory Bandwidth Optimizations for Wide-Bus Machines  

E-print Network

One of the critical problems facing designers of high performance processors is the disparity between processor speed and memory speed. This has occurred because innovation and technological improvements in processor design have outpaced advances in memory design. While not a panacea, some gains in memory performance can be had by simply increasing the width of the bus from the processor to memory. Indeed, high performance microprocessors with wide buses (i.e., capable of transferring 64 bits or more between the CPU and memory) are beginning to become commercially available (e.g. MIPS R4000, DEC Alpha, and Motorola 88110). This paper discusses some compiler optimizations that take advantage of the increased bandwidth available from a wide bus. We have found that very simple strategies can reduce the number of memory requests by 10 to 15 percent. For some data and compute intensive algorithms, more aggressive optimizations can yield significantly higher reductions. The paper describes t...

Michael J. Alexander; Michael J. Alexander; Postal Address; Professor Jack; Jack W. Davidson; Michael A. Alexander; Mark W. Bailey; Mark W. Bailey; Mark W. Bailey; Bruce R. Childers; Bruce R. Childers; Bruce R. Childers; Jack W. Davidson; Jack W. Davidson; Jack W. Davidson; Sanjay Jinturkar; Sanjay Jinturkar; Sanjay Jinturkar

1992-01-01

313

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

314

Heat storage for a bus petrol internal-combustion engine  

Microsoft Academic Search

The heat storage (HS) system for pre-heating a bus petrol internal combustion engine to starting was mathematically modelled\\u000a and experimentally investigated. The development of such devices is an extremely urgent problem especially for regions with\\u000a a cold climate. We discuss how HS works on the effect of absorption and rejection of heat energy at a solid-liquid phase change\\u000a of a

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

315

Structure and Metrology for an Analog Testability Bus  

Microsoft Academic Search

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

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

1993-01-01

316

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

E-print Network

Learning the Metro Bus System / For Cowell Students This guide summarizes the main bus routes space on crowded Metro buses for students headed off-campus. No need to show your student ID on campus shuttles. Choose Metro (SCMTD) buses to go to OFF-CAMPUS destinations. Have your student ID card

Renau, Jose

317

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

318

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

319

Pilot Survey of Subway and Bus Stop Noise Levels  

PubMed Central

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

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

2006-01-01

320

Hybrid electric 40 foot heavy duty transit bus  

SciTech Connect

The authors describe the development of an advanced hybrid electric drive system for a ULEV transit bus. In transit applications, hybrid electric drive systems enjoy distinct advantages over all battery powered electric and conventional diesel drive systems. These advantages include reduced weight, high efficiency, extended range, and reduced emissions. For this application a conventional RTS T80208 transit bus was converted from diesel to hybrid electric drive, consisting of a 190 kW brushless DC permanent magnet traction motor, a propane fueled rotary engine generator set, nickel cadmium batteries, and control and power conditioning electronics. The 120 kW generator set was sized to supply the auxiliary power and mean propulsion power with the engine running at nearly constant speed at its highest efficiency and lowest emission operating point. The nominal 270 volt battery pack was sized to supply peak power of up to 120 kW; battery charging was achieved either through regenerative braking or the generator set. Passenger capacity and operational capability remain unchanged as a result of the conversion. The hybrid electric bus can run urban routes over a ten hour day without refueling or external battery charging. A detailed description of the system is provided in this paper.

Rezza, P. Jr.; Wu, A. [Kaman Electromagnetic Corp., Hudson, MA (United States)

1994-12-31

321

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

322

Battery management system with dual-balancing mechanism for LiFePO4 battery module  

Microsoft Academic Search

This paper presents a battery management system of LiFePO4 battery module with dual-balancing mechanism. First, the employed battery management can accurately capture some important parameters of the LiFePO4 battery module, including voltage, current, temperature, and providing protection functions for the battery module. Next, these obtained parameters of the battery are transmitted to the microcontroller through the inter-integrated circuit (I2C-bus). And

Chang-Hua Lin; Hsuan-Yi Chao; Chien-Ming Wang; Min-Hsuan Hung

2011-01-01

323

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

SciTech Connect

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

Eudy, L.; Chandler, K.

2012-05-01

324

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

325

Design of bus-on-chip core for micro-satellite avionics  

Microsoft Academic Search

This paper discusses a layout of bus-on-chip core referring to SoC thinking which is composed of six sections based on a physical chip of FPGA: multi-Processor cache coherence unit, external bus control module, TT&C module, Ethernet Mac interface, EDAC\\/DMA module, and AMBA bridges. Multi-processor cache coherence unit, as a key part of the bus core, is used to serve the

Youjun Liu; Zheng You; Bin Li; Xiangqi Zhang; Ziyang Meng

2007-01-01

326

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

327

Transient probabilities for queues with applications to hospital waiting list management.  

PubMed

In this paper we study queuing systems within the NHS. Recently imposed government performance targets lead NHS executives to investigate and instigate alternative management strategies, thereby imposing structural changes on the queues. Under such circumstances, it is most unlikely that such systems are in equilibrium. It is crucial, in our opinion, to recognise this state of affairs in order to make a balanced assessment of the role of queue management in the modern NHS. From a mathematical perspective it should be emphasised that measures of the state of a queue based upon the assumption of statistical equilibrium (a pervasive methodology in the study of queues) are simply wrong in the above scenario. To base strategic decisions around such ideas is therefore highly questionable and it is one of the purposes of this paper to offer alternatives: we present some (recent) research whose results generate performance measures and measures of risk, for example, of waiting-times growing unacceptably large; we emphasise that these results concern the transient behaviour of the queueing model-there is no asssumption of statistical equilibrium. We also demonstrate that our results are computationally tractable. PMID:16134436

Joy, Mark; Jones, Simon

2005-08-01

328

Propagation speed of a starting wave in a queue of pedestrians  

NASA Astrophysics Data System (ADS)

The propagation speed of a starting wave, which is a wave of people's successive reactions in the relaxation process of a queue, has an essential role for pedestrians and vehicles to achieve smooth movement. For example, a queue of vehicles with appropriate headway (or density) alleviates traffic jams since the delay of reaction to start is minimized. In this paper, we have investigated the fundamental relation between the propagation speed of a starting wave and the initial density by both our mathematical model built on the stochastic cellular automata and experimental measurements. Analysis of our mathematical model implies that the relation is characterized by the power law ??-? (??1), and the experimental results verify this feature. Moreover, when the starting wave is characterized by the power law (?>1), we have revealed the existence of optimal density, where the required time, i.e., the sum of the waiting time until the starting wave reaches the last pedestrian in a queue and his/her travel time to pass the head position of the initial queue, is minimized. This optimal density inevitably plays a significant role in achieving a smooth movement of crowds and vehicles in a queue.

Tomoeda, Akiyasu; Yanagisawa, Daichi; Imamura, Takashi; Nishinari, Katsuhiro

2012-09-01

329

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

330

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

PubMed Central

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

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

2007-01-01

331

A queueing approach to multi-site enzyme kinetics.  

PubMed

Multi-site enzymes, defined as where multiple substrate molecules can bind simultaneously to the same enzyme molecule, play a key role in a number of biological networks, with the Escherichia coli protease ClpXP a well-studied example. These enzymes can form a low latency 'waiting line' of substrate to the enzyme's catalytic core, such that the enzyme molecule can continue to collect substrate even when the catalytic core is occupied. To understand multi-site enzyme kinetics, we study a discrete stochastic model that includes a single catalytic core fed by a fixed number of substrate binding sites. A natural queueing systems analogy is found to provide substantial insight into the dynamics of the model. From this, we derive exact results for the probability distribution of the enzyme configuration and for the distribution of substrate departure times in the case of identical but distinguishable classes of substrate molecules. Comments are also provided for the case when different classes of substrate molecules are not processed identically. PMID:24904740

Hochendoner, Philip; Ogle, Curtis; Mather, William H

2014-06-01

332

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

333

Priority queues with bursty arrivals of incoming tasks.  

PubMed

Recently increased accessibility of large-scale digital records enables one to monitor human activities such as the interevent time distributions between two consecutive visits to a web portal by a single user, two consecutive emails sent out by a user, two consecutive library loans made by a single individual, etc. Interestingly, those distributions exhibit a universal behavior, D(tau) approximately tau(-delta) , where tau is the interevent time, and delta approximately 1 or 32 . The universal behaviors have been modeled via the waiting-time distribution of a task in the queue operating based on priority; the waiting time follows a power-law distribution P(w)(tau) approximately tau(-alpha) with either alpha=1 or 32 depending on the detail of queuing dynamics. In these models, the number of incoming tasks in a unit time interval has been assumed to follow a Poisson-type distribution. For an email system, however, the number of emails delivered to a mail box in a unit time we measured follows a power-law distribution with general exponent gamma . For this case, we obtain analytically the exponent alpha , which is not necessarily 1 or 32 and takes nonuniversal values depending on gamma . We develop the generating function formalism to obtain the exponent alpha , which is distinct from the continuous time approximation used in the previous studies. PMID:19392017

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

2009-03-01

334

Priority queues with bursty arrivals of incoming tasks  

NASA Astrophysics Data System (ADS)

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

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

2009-03-01

335

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.

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

2014-01-01

336

STOCK RATIONING IN A MULTI-CLASS MAKE-TO-STOCK QUEUE WITH INFORMATION ON THE PRODUCTION STATUS  

E-print Network

STOCK RATIONING IN A MULTI-CLASS MAKE-TO-STOCK QUEUE WITH INFORMATION ON THE PRODUCTION STATUS Engineering Ko¸c University 34450, Sariyer, Istanbul, TURKEY fkaraesmen@ku.edu.tr #12;Stock Rationing in a Multi-class Make-to-Stock Queue with Information on the Production Status August 17, 2006 Abstract We

Karaesmen, Fikri

337

The abstract Cauchy problem for the non-stationary bulk queue M(t)|M[k, B]|1  

E-print Network

We derived state probability equations describing the queue M(t)|M[k, B]|1 and formulated as an abstract Cauchy problem to investigate by means of the semi-group theory of bounded linear operators in functional analysis. For the abstract Cauchy problem of this queue, we determined the eigenfunctions of maximal operator and showed some properties of the Dirichlet operator.

Yong Chol Chon

2013-11-05

338

A COMPARISON OF AIRCRAFT TRAJECTORY-BASED AND AGGREGATE QUEUE-BASED CONTROL OF AIRPORT TAXI PROCESSES  

E-print Network

A COMPARISON OF AIRCRAFT TRAJECTORY-BASED AND AGGREGATE QUEUE-BASED CONTROL OF AIRPORT TAXI of aircraft at airports by optimizing surface operations. A simple surface traffic optimization approach is to hold aircraft back at the gates based on aggregate information on surface queues. Depending

Gummadi, Ramakrishna

339

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

340

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

341

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

342

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

343

Design and analysis of a model predictive controller for active queue management.  

PubMed

Model predictive (MP) control as a novel active queue management (AQM) algorithm in dynamic computer networks is proposed. According to the predicted future queue length in the data buffer, early packets at the router are dropped reasonably by the MPAQM controller so that the queue length reaches the desired value with minimal tracking error. The drop probability is obtained by optimizing the network performance. Further, randomized algorithms are applied to analyze the robustness of MPAQM successfully, and also to provide the stability domain of systems with uncertain network parameters. The performances of MPAQM are evaluated through a series of simulations in NS2. The simulation results show that the MPAQM algorithm outperforms RED, PI, and REM algorithms in terms of stability, disturbance rejection, and robustness. PMID:21963108

Wang, Ping; Chen, Hong; Yang, Xiaoping; Ma, Yan

2012-01-01

344

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

345

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

346

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

347

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

348

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

349

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

350

Development of an integrated cryogenic bus for spacecraft applications  

NASA Astrophysics Data System (ADS)

To improve the efficiency and reduce the overdesign penalties associated with integrating cryogenic systems into spacecraft, the Integrated Cryogenic Bus (ICB) program was initiated in April 1996. The technical objectives of the program were to develop an integrated, lightweight means of thermally linking a cryogenic cooling source to a cooled satellite component, to commonize the interfaces to the cooling source and cooled component, and to commonize the integration of these systems into spacecraft. The technical plan involves several steps beginning with the definition of requirements, the identification and characterization of potential bus components, the development of new concepts and optimization methods, breadboard testing, and prototype development. Six months into the program, over 25 cryocooler, focal plane, and cryogenic hardware organizations have been interviewed or surveyed to identify requirements, numerous components have been identified and characterized, several preliminary concepts have been developed, an optimization plan has been outlined, and critical breadboard tests have begun. This paper summarizes the progress to date during Phase I of this Phillips Laboratory program funded by the Ballistic Missile Defense Organization (BMDO).

Bugby, David C.; Brennan, Patrick J.; Davis, Thomas M.; Tomlinson, Joe; Stoyanof, Marko; Crawford, Larry; Glaister, David S.

1997-01-01

351

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

352

Finite-State Analysis of the CAN Bus Protocol Michiel van Osch Scott A. Smolka  

E-print Network

Finite-State Analysis of the CAN Bus Protocol Michiel van Osch Scott A. Smolka Eindhoven University Network (CAN), a high-speed serial bus system with real-time capabilities, widely used in embedded systems. CAN's primary application domain is automotive, and the physical and data link layers of the CAN

Smolka, Scott

353

Data acquisition system based on CompactPCI bus and FPGA for electrical resistance tomography  

Microsoft Academic Search

As a kind of visual measurement technique based upon variations in conductivity, electrical resistance tomography has great potential in process application. A new data acquisition system for electrical resistance tomography is described. This data acquisition system is built based on the CompactPCI bus and the FPGA. The application of the CompactPCI bus can make the single plane electrical resistance tomography

Zhiqiang Zhang; Feng Dong; Cong Xu

2011-01-01

354

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

355

A Comparison of State Methods of Purchasing School Bus Bodies. Monographs in Education No. 6.  

ERIC Educational Resources Information Center

The purpose of this study was to explore alternative methods for saving public funds in the purchasing of school bus bodies in the state of Georgia. Officials from each of the 50 states responded to a questionnaire that solicited descriptions of the methods used by state officials in purchasing school bus bodies. The discussion focuses on (1) the…

Bryans, Charles Michael

356

This Could Save Your Child's Life. A School Bus Handrail Handbook.  

ERIC Educational Resources Information Center

School-bus handrails have had the same basic design for more than 30 years. However, students' recent propensity to wear oversized and baggy clothing increases the likelihood that clothing or accessories may become snagged on bus handrails. Children across the United States have been injured or killed when their clothing or accessories caught in…

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

357

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

E-print Network

Power-optimal Encoding for DRAM Address Bus Wei-Chung Cheng and Massoud Pedram University Pyramid code, an optimal code for transmitting sequential addresses over a DRAM bus. Constructed Modern electronic systems have a dichotomy of simultaneously needing to be low power and high performance

Pedram, Massoud

358

Bus Str Sustainability Spring 2011 MGT 6359: BUSINESS STRATEGIES FOR SUSTAINABILITY  

E-print Network

Bus Str Sustainability Spring 2011 1/11 MGT 6359: BUSINESS STRATEGIES FOR SUSTAINABILITY Professor and management tools Corporate environmental programs Sustainable development Environmental marketing and capitalizing on these opportunities. #12;Bus Str Sustainability Spring 2011 2/11 Course Outline The course

Li, Mo

359

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

360

Resource allocation in a dynamically partitionable bus network using a graph coloring algorithm  

Microsoft Academic Search

An efficient dynamic graph traversal algorithm is used to identify nonconflicting requests and to allocate network resources in a dynamically partitionable bus network (DPBN). In centralized network control a special processor receives from the control computer of a partitionable bus network an adjacency matrix which indicates conflicts among requests. It applies the dynamic graph traversal algorithm and returns the identified

Tai-Kuo Woo; Stanley Y. W. Su; Richard Newman-Wolfe

1991-01-01

361

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.

362

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

363

Adaptive Task Flow Management of Distributed Spacecraft Bus based on Multi Agent Reinforcement Learning  

Microsoft Academic Search

Distributed systems have been intensively researched for large-scaled systems which require scalability in design phase and robustness in operation phase. In this paper, the concept of Distributed Spacecraft Bus (DSB) is proposed. Components of spacecraft bus are distributed to form a multi-agent system. In order to achieve high performance as well as fault tolerance, a novel method of adaptive task

Takashi Eishima; Shinichi Nakasuka

2005-01-01

364

Evoking Emotions and Unpacking Layered Histories through Young Children's Illustrations of Racial Bus Segregation  

ERIC Educational Resources Information Center

Drawing on theories of multi-modality and critical visual literacy, this article focuses on images that five-and six year-olds painted in a class-made book, Voice on the Bus, about racial segregation. The article discusses how children used illustrations to convey their understandings of Rosa Parks' bus arrest in Alabama. A post-structural view…

Kuby, Candace R.

2013-01-01

365

Running time variability and resource allocation : a data-driven analysis of high-frequency bus operations  

E-print Network

Running time variability is one of the most important factors determining service quality and operating cost of high-frequency bus transit. This research aims to improve performance analysis tools currently used in the bus ...

Sánchez-Martínez, Gabriel Eduardo

2013-01-01

366

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

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false How does a school calculate annual bus transportation miles...THE INTERIOR EDUCATION THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation...Transportation Miles § 39.711 How does a school calculate annual bus transportation...

2013-04-01

367

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

Code of Federal Regulations, 2014 CFR

... 2014-04-01 false How does a school calculate annual bus transportation miles...THE INTERIOR EDUCATION THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation...Transportation Miles § 39.711 How does a school calculate annual bus transportation...

2014-04-01

368

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

369

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

370

A Shared-Bus Control Mechanism and a Cache Coherence Protocol for a High-Performance On-Chip Multiprocessor  

Microsoft Academic Search

A new cache coherence solution is proposed for an over 500 MHz on-chip multiprocessor using advanced VLSI technology. In order to reduce shared-bus transaction time, the central coherence unit (CCU) is introduced. The CCU controls all shared-bus transactions, monitoring all cache rays every clock cycle, and executes a bus transaction in four clock cycles while a conventional bus mechanism requires

Masafumi Takahashi; Hiroyuki Takano; Emi Kaneko; Seigo Suzuki

1996-01-01

371

An Analytical Model of the CAN Bus for Online Schedulability Test Zhenwu Shi and Fumin Zhang, Georgia Institute of Technology  

E-print Network

An Analytical Model of the CAN Bus for Online Schedulability Test Zhenwu Shi and Fumin Zhang, Georgia Institute of Technology Abstract--Controller area network (CAN) is a priority- based bus that supports real-time communication. Existing schedulability analysis for the CAN bus is peformed

Zhang, Fumin

372

Controller Area Network (CAN) Schedulability Analysis with FIFO queues Robert I. Davis  

E-print Network

Controller Area Network (CAN) Schedulability Analysis with FIFO queues Robert I. Davis Real-ulm.de Abstract-- Controller Area Network (CAN) is widely used in automotive applications. Existing schedulability analysis for CAN is based on the assumption that the highest priority message ready for transmission

Ulm, Universität

373

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

374

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

375

Complexity-Effective Issue Queue Design Under Load-Hit Speculation  

Microsoft Academic Search

Current trends in microprocessor designs indicate increasing pipeline depth in order to keep up with higher clock frequencies and increased architectural complexity. Speculatively issued in- structions may be particularly sensitive to increase in pipeline depth, assuming that issued instructions are kept in the issue queue. In this paper, we evaluate the effectiveness of load hit spec- ulation as pipeline depth

Tali Moreshet; R. Iris Bahar

2002-01-01

376

Solving Layered Queueing Networks of Large Client-Server Systems with Symmetric Replication  

E-print Network

in multi-tiered client server systems in which the response time of an entity is not only de- pendentSolving Layered Queueing Networks of Large Client-Server Systems with Symmetric Replication Tariq University Ottawa, ON Canada K1S 5B6 {tomari,greg,cmw,amy}@sce.carleton.ca ABSTRACT Large distributed client

Woodside, C. Murray

377

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

E-print Network

Index Policies for a Multi-Class Queue with Convex Holding Cost and Abandonments M. Larra~naga1 of no abandonments and lin- ear holding cost, our index coincides with the cµ-rule, which is known to be optimal, which allows us to derive the asymptotic structure of the index policies, and (ii) as the abandonment

Ayesta, Urtzi

378

Rational Abandonment from Tele-Queues: Nonlinear Waiting Costs with Heterogeneous Preferences  

E-print Network

Rational Abandonment from Tele-Queues: Nonlinear Waiting Costs with Heterogeneous Preferences Nahum Shimkin 1 and Avishai Mandelbaum 2 November 2003 Abstract We consider the modelling of abandonment from. These equilibria may be viewed as stable operating points of the system, and determine the customer abandonment pro

Shimkin, Nahum

379

Transient and busy period analysis of theGI\\/G\\/1 queue: The method of stages  

Microsoft Academic Search

In this paper we study the transient behavior of the MGEL\\/MGEM\\/1 queueing system, where MGE is the class of mixed generalized Erlang distributions which can approximate an arbitrary distribution. We use the method of stages combined with the separation of variables and root finding techniques together with linear and tensor algebra. We find simple closed form expressions for the Laplace

Dimitris J. Bertsimas; Daisuke Nakazato

1992-01-01

380

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

E-print Network

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

Karaesmen, Fikri

381

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

E-print Network

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

Mendonça, David

382

Numerical analysis of M/G/1 type queueing systems with Phase-type transition structure  

E-print Network

Numerical analysis of M/G/1 type queueing systems with Phase-type transition structure T. ´Elteto1 and present an numerically stable al- gorithm for the steady state analysis of the approximate model. We show results describe the numerical calculation of the steady state distribution of an M/G/1/ type Markov chain

Telek, Miklós

383

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

384

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

385

Brownian models of multiclass queueing networks: Current status and open problems  

Microsoft Academic Search

This paper is concerned with Brownian system models that arise as heavy traffic approximations for open queueing networks. The focus is on model formulation, and more specifically, on the formulation of Brownian models for networks with complex routing. We survey the current state of knowledge in this dynamic area of research, including important open problems. Brownian approximations culminate in estimates

J. Michael Harrison; Viên Nguyen

1993-01-01

386

Flow-Through-Queue based Power Management for Gigabit Ethernet Controller1  

E-print Network

link speeds continue to grow exponentially, a Gigabit Ethernet controller is becoming more complex consumption increases rapidly with increase in link speed [2]. Thus, designers of the Gigabit EthernetFlow-Through-Queue based Power Management for Gigabit Ethernet Controller1 Hwisung Jung Andy Hwang

Pedram, Massoud

387

Advances in Applied Probability, 1995 The Probability of Large Queue Lengths and  

E-print Network

Advances in Applied Probability, 1995 The Probability of Large Queue Lengths and Waiting Times Purdue University West Lafayette, IN 47907 USA Abstract We consider a multiserver queuing process establish conditions for the queuing process to be characterized as a geometrically Harris recurrent Markov

Szpankowski, Wojciech

388

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

NASA Astrophysics Data System (ADS)

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

Park, Byungsung; Yoo, Jaeyeong; Kim, Hagbae

389

Queueing Syst (2010) 65: 175209 DOI 10.1007/s11134-010-9170-5  

E-print Network

Queueing Syst (2010) 65: 175­209 DOI 10.1007/s11134-010-9170-5 Busy period, virtual waiting time the distributions of the main characteristics of the queuing system, such as the busy period, the time of the first loss of a customer, the number of customers in the system, the virtual waiting time in transient

Einmahl, Uwe

390

Priority queues with bursty arrivals of incoming tasks N. Masuda,1  

E-print Network

modeled via the waiting-time distribution of a task in the queue operating based on priority; the waiting time follows a power-law distribution Pw - with either =1 or 3/2 depending on the detail of queuing­5 . Such a bursty nature of human dynamics has been understood to be a consequence of queuing processes driven

Kahng, Byungnam

391

Time Dependent Priority Queues Author(s): Leonard Kleinrock and Roy P. Finkelstein  

E-print Network

are given to display the behavior of the waiting time vari- ance. AMONG those priority queuing systems is a class of rth order delay-dependent priority queuing dis- ciplines in which a customer from the pth result states that the expected wait on queue for p-type customers in an rth order system with parameter

Kleinrock, Leonard

392

A slow-to-start traffic model related to a M/M/1 queue  

NASA Astrophysics Data System (ADS)

We consider a system of ordered cars moving in \\mathbb {R} from right to left. Each car is represented by a point in \\mathbb {R} ; two or more cars can occupy the same point but cannot overpass. Cars have two possible velocities: either 0 or 1. An unblocked car needs an exponential random time of mean 1 to pass from speed 0 to speed 1 (slow-to-start). Car i, say, travels at speed 1 until it (possibly) hits the stopped car i-1 to its left. After the departure of car i-1, car i waits an exponential random time to change its speed to 1, travels at this speed until it hits again stopped car i-1 and so on. Initially cars are distributed in \\mathbb {R} according to a Poisson process of parameter ?<1. We show that every car will be stopped only a finite number of times and that the final relative car positions are again a Poisson process with parameter ?. To do that, we relate the trajectories of the cars to an M/M/1 stationary queue as follows. Space in the traffic model is time for the queue. The initial positions of the cars coincide with the arrival process of the queue and the final relative car positions match the departure process of the queue.

Castellares Cáceres, Fredy; Ferrari, Pablo A.; Pechersky, Eugene

2007-07-01

393

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.

394

The effects of active queue management and explicit congestion notification on web performance  

Microsoft Academic Search

We present an empirical study of the effects of ac- tive queue management (AQM) and explicit congestion notification (ECN) on the distribution of response times experienced by users browsing the Web. Three prominent AQM designs are considered: the Proportional Integral (PI) controller, the Random Exponential Marking (REM) controller, and Adaptive Random Early Detec- tion (ARED). The effects of these AQM

Long Le; Jay Aikat; Kevin Jeffay; F. Donelson Smith

2007-01-01

395

The effects of active queue management and explicit congestion notification on web performance  

Microsoft Academic Search

We present an empirical study of the effects of active queue management (AQM) and explicit congestion notification (ECN) on the distribution of response times experienced by users browsing the Web. Three prominent AQM designs are considered: the Proportional Integral (PI) controller, the Random Exponential Marking (REM) controller, and Adaptive Random Early Detection (ARED). The effects of these AQM designs were

Long Le; Jay Aikat; Kevin Jeffay; F. Donelson Smith

2007-01-01

396

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

397

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

398

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

E-print Network

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

Guillemin, Fabrice

399

Design and Application of Queue-Buffer Communication Model in Pneumatic Conveying  

Microsoft Academic Search

In order to communicate with a PLC (Programmable Logic Controller) flexibly and freely, a data communication model based on the PLC's free port is designed. In the structure of the model, a distributed data communication environment is constructed by using Ethernet and serial adapters. In the communication algorithm, a method of queue- buffer for multi-threaded is used to improve the

Liping Zhang; Haomin Hu

2013-01-01

400

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

401

Queueing Behavior of Hashing Methods Used to Build URL Routing Tables  

E-print Network

Queueing Behavior of Hashing Methods Used to Build URL Routing Tables Zornitza Genova Prodanoff behavior. We examine hashing as applied to URL routing used in Content Distribution Networks (CDNs). URL can be very insightful. Fig. 1 URL router forwarding or redirecting a request I. INTRODUCTION Content

Prodanoff, Zornitza Genova

402

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

Microsoft Academic Search

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

N. g. Duffield; Neil Connell

1994-01-01

403

Analysis of Multi-Server Queues with Station and Server Vacations  

E-print Network

Analysis of Multi-Server Queues with Station and Server Vacations Xiuli Chao Department and server vacation. In the first one, all the servers take vacation si- multaneously whenever the system vacation for all servers. This phe- nomenon occurs in practice, for example, when the system consists

Zhao, Yiqiang Q.

404

Input and output queueing packet switch with backpressure mode for loss sensitive packets in threshold scheme  

Microsoft Academic Search

We propose an N×N input and output queueing packet switch model with backpressure mode for loss sensitive packets in threshold scheme. In the proposed model, delay sensitive packets gain an advantage over loss sensitive packets at input and output ports and backpressure mode is applied for loss sensitive packets. We evaluate the average system delay and the packet loss probability

Takeshi Kanazawa; Toshiki Endo; Shigeki Shiokawa; Iwao Sasase

1997-01-01

405

DATADRAW: A Command Language for Manipulating and Displaying Stacks, Queues, Lists and Trees.  

ERIC Educational Resources Information Center

DATADRAW is a command language, written in FORTRAN IV, to manipulate stacks, queues, lists and trees, and to display them on the CDC 252 scope system attached to a CDC 6600. A DATADRAW primer is given, and the algorithms for updating and displaying structures are described. It is noted that DATADRAW was designed to be a simple command language…

Siklossy, L.; And Others

406

Queueing Syst (2012) 71:7995 DOI 10.1007/s11134-012-9284-z  

E-print Network

on the speed of convergence to sta- tionarity for unreliable queueing networks, as in Lorek and Szekli [13 state space. A spe- cial case is a stochastically monotone birth-and-death process for which the strong to be again a birth-and-death process on the same state space. Times to absorption are usually m

Lorek, Pawel

407

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

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

408

MDP Based Optimal Pricing for a Cloud Computing Queueing Rami Atar Israel Cidon Mark Shifrin  

E-print Network

MDP Based Optimal Pricing for a Cloud Computing Queueing Model Rami Atar Israel Cidon Mark Shifrin] and especially cloud computing services at both consumer and enterprise markets [12], [18]. Previous MDP formulations for cloud computing applications can be found in [13] and [14]. These works optimize the decision

Atar, Rami

409

Resequencing Delays Under Multipath Routing - Asymptotics in a Simple Queueing Model  

Microsoft Academic Search

To study the resequencing delay caused by multipath routing, we consider a system of parallel queues under random routing as a model of network routing behavior. The impact of resequencing on packet end-to-end delay is explored through the newly introduced resequencing index. We compute this new metric under several distributional asumptions (e.g., light vs. heavy tails) on routing delays.

Yijie Han; Armand M. Makowski

2006-01-01

410

A distributed self-clocked fair queueing architecture for wireless ATM networks  

Microsoft Academic Search

The application of asynchronous transfer mode (ATM) to a wireless local area network (WLAN) environment is a new undertaking and poses many problems not found in either wireline ATM or data-only WLAN networks. The WLAN is designed as a centralized network, where a complex base station polls simpler remote stations. A polling algorithm called distributed fair queueing (DFQ) is developed

Richard Kautz; A. Leon-Garcia

1997-01-01

411

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

Microsoft Academic Search

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

Dimitrios Stiliadis; Anujan Varma

1998-01-01

412

Queue Management Strategies to Improve TCP Fairness in IEEE 802.11 Wireless LANs  

E-print Network

Queue Management Strategies to Improve TCP Fairness in IEEE 802.11 Wireless LANs Mingwei Gong Qian,qianwu,carey}@cpsc.ucalgary.ca Abstract-- Wireless Local Area Networks (WLANs) based on the IEEE 802.11 technology have become increasingly popular and ubiquitous. The 802.11 standard allows each station in a WLAN equal opportunity

Williamson, Carey

413

A Queue Theory-Based Approach to Staff Software Maintenance Centers G. Antoniol  

E-print Network

of the management of software projects. Software develop- ment and maintenance are labor intensive; the project cost technologies to cooperate. Communi- cation technologies and infrastructures allow the compa- nies to create centers coop- erated. Queue theory allowed effective control of the process supporting project management

Di Penta, Massimiliano

414

Improved blood pressure control among school bus drivers with hypertension.  

PubMed

The impact of a hypertension awareness and educational program, BP DownShift, was evaluated among school bus drivers in a southern US state. At baseline (August 2007), blood pressure (BP) measurements, self-reported demographics, and hypertension awareness and management practices were collected from drivers who consented to participate in the study. Interventions included 4 educational mailings, installation of BP machines at all bus terminals, and access to free dietitian consultations and gym memberships. BP was evaluated using Department of Transportation guidelines. BP was remeasured and a survey was administered at follow-up (May 2008). At baseline, 208 drivers consented to the BP screening; 120 (58%) returned for a follow-up assessment. Most participants completing the study were female (73%) and African American (72%). Mean age was 50 years and mean body mass index was 32 kg/m(2); 52% of participants were obese. In all, 58% of participants reported a prior diagnosis of hypertension by a physician, and 63% reported taking antihypertensive medication. Both systolic and diastolic BP (SBP and DBP) were lower at follow-up (135/82 mmHg vs. 145/87 mmHg at baseline; P < 0.001, both comparisons); 42% had a reduction in SBP > 10 mmHg, and 44% had a reduction in DBP > 5 mmHg. At follow-up, 58% were controlled to BP < 140/90, compared to 38% at baseline (P < 0.001). At follow-up, an increased proportion of previously diagnosed drivers reported home BP monitoring, healthy diet, and regular exercise as components of hypertension self-management. The implementation of our hypertension education, self-management, and awareness program was associated with an improvement in BP control, which may positively impact commercial driver's license recertification as well as improve employee health. PMID:20415620

Doyle, Joseph; Severance-Fonte, Tina; Morandi-Matricaria, Elizabeth; Wogen, Jenifer; Frech-Tamas, Feride

2010-04-01

415

Optimal Control Strategy Design Based on Dynamic Programming for a Dual-Motor Coupling-Propulsion System  

PubMed Central

A dual-motor coupling-propulsion electric bus (DMCPEB) is modeled, and its optimal control strategy is studied in this paper. The necessary dynamic features of energy loss for subsystems is modeled. Dynamic programming (DP) technique is applied to find the optimal control strategy including upshift threshold, downshift threshold, and power split ratio between the main motor and auxiliary motor. Improved control rules are extracted from the DP-based control solution, forming near-optimal control strategies. Simulation results demonstrate that a significant improvement in reducing energy loss due to the dual-motor coupling-propulsion system (DMCPS) running is realized without increasing the frequency of the mode switch.

Zhang, Shuo; Zhang, Chengning; Han, Guangwei; Wang, Qinghui

2014-01-01

416

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

417

Dual Gravity and Matter  

E-print Network

We consider the problem of finding a dual formulation of gravity in the presence of non-trivial matter couplings. In the absence of matter a dual graviton can be introduced only for linearised gravitational interactions. We show that the coupling of linearised gravity to matter poses obstructions to the usual construction and comment on possible resolutions of this difficulty.

Eric A. Bergshoeff; Mees de Roo; Sven F. Kerstan; Axel Kleinschmidt; Fabio Riccioni

2008-03-27

418

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

419

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

420

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

421

Bounds on Average Delays and Queue Size Averages and Variances in Input-Queued Cell-Based Switches  

Microsoft Academic Search

In this paper we develop a general methodology, mainly based upon Lyapunov functions, to derive bounds on average delays, and on queue size averages and variances of complex systems of queues. We then apply this methodology to input-buffered, cell-based switch and router ar- chitectures. These architectures require a scheduling algorithm to select at each slot a subset of input-buffered cells

Emilio Leonardi; Marco Mellia; Fabio Neri; Marco Ajmone Marsan

2001-01-01

422

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

423

Analysis of a conditional active bus priority strategy in a coordinated signal system  

E-print Network

objective of the experiment was to develop an evaluation methodology which could be used by engineers to determine how a priority strategy would operate prior to implementation. The priority strategy developed used two methods to benefit bus movement. One...

Beasley, Phillip Scott

1995-01-01

424

Leveraging infrastructure : sustainable bus rapid transit route planning in Beirut, Lebanon  

E-print Network

This thesis applies the concepts of urban design, public transportation planning, economic development, and sustainability, to the routing and site plan of a two-kilometer bus rapid transit (BRT) line segment into downtown ...

Nabti, Jumana M., 1976-

2004-01-01

425

Simulating service reliability of a high frequency bus route using automatically collected data  

E-print Network

High frequency bus routes are subject to a variety of influences that can affect the quality of service provided to passengers. Since they have short headways and high passenger demand interaction between buses can easily ...

Milkovits, Martin Nicholas

2008-01-01

426

Scheduling bus services in Universiti Teknologi MARA (UiTM) Shah Alam  

NASA Astrophysics Data System (ADS)

This study deals with bus scheduling problem in a local public university. Given existing bus daily trips, set of buses used and set of policy, the aims of this study are to optimize the use of buses for in-campus trips and to cover the trip demands. This study is conducted at Universiti Teknologi Mara (UiTM) Shah Alam that involves six-zone trips and a single depot. The bus scheduling problem in UiTM is formulated using the integer programming model and the LINGO 12.0 software is used for solving this bus scheduling model. The results of this model showed that the number of buses can be reduced during off-peak hours. Furthermore, optimal trips can also be identified from the results.

Omar, Mawardi; Ismail, Wan Rosmanira; Oughalime, Ahmed

2014-09-01

427

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

NASA Astrophysics Data System (ADS)

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

Ge, Ying-long

2013-07-01

428

APPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY Appl. Stochastic Models Bus. Ind., 2005; 21:111136  

E-print Network

APPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY Appl. Stochastic Models Bus. Ind., 2005; 21 a feature space. To summarize, there are three benefits to transform the data into H 1. It lets us define

429

77 FR 74452 - Bus Testing: Calculation of Average Passenger Weight and Test Vehicle Weight  

Federal Register 2010, 2011, 2012, 2013, 2014

...2132-AB01 Bus Testing: Calculation of Average Passenger Weight and Test Vehicle Weight AGENCY: Federal Transit Administration (FTA...regulation to increase the assumed average passenger weight value used for ballasting test buses from the...

2012-12-14

430

Optimal vehicle control strategy of a fuel cell\\/battery hybrid city bus  

Microsoft Academic Search

In this article, an optimal vehicle control strategy based on a time-triggered controller area network (TTCAN) system for a polymer electrolyte membrane (PEM) fuel cell\\/nickel-metal hydride (Ni-MH) battery powered city bus is presented. Aiming at improving the fuel economy of the city bus, the control strategy comprises an equivalent consumption minimization strategy (ECMS) and a braking energy regeneration strategy (BERS).

Liangfei Xu; Jianqiu Li; Jianfeng Hua; Xiangjun Li; Minggao Ouyang

2009-01-01

431

Optimal energy management for a series–parallel hybrid electric bus  

Microsoft Academic Search

This paper aims to present a new type of series–parallel hybrid electric bus and its energy management strategy. This hybrid bus is a post-transmission coupled system employing a novel transmission as the series–parallel configuration switcher. In this paper, the vehicle architecture, transmission scheme and numerical models are presented. The energy management system governs the mode switching between the series mode

Weiwei Xiong; Yong Zhang; Chengliang Yin

2009-01-01

432

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

E-print Network

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

Brohlin, Paul LeRoy

1988-01-01

433

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

E-print Network

THE PREDICTION OF BUS ARRIVAL TIME USING AUTOMATIC VEHICLE LOCATION SYSTEMS DATA A Dissertation by RAN HEE JEONG Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of DOCTOR OF PHILOSOPHY December 2004 Major Subject: Civil Engineering THE PREDICTION OF BUS ARRIVAL TIME USING AUTOMATIC VEHICLE LOCATION SYSTEMS DATA A Dissertation by RAN HEE JEONG Submitted to Texas...

Jeong, Ran Hee

2005-02-17

434

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

E-print Network

;Customer Satisfaction with Service Attributes and Overall Service BRT Bus Metro Mean Ranking Mean Ranking.44 3.41 3.39 3.34 3.26 3.21 3.13 Ordinal Score #12;Customer Satisfaction with BUS Service Attributes 0.9 Ordinal Score #12;Customer Satisfaction with METRO Service Attributes 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 3

Minnesota, University of

435

Research of network transmission of process bus based upon IEC 61850  

Microsoft Academic Search

The real-time and reliable transmission of the sampled values and trip signals via the Ethernet is an important function of the smart substation process bus communication based upon IEC61850, but there involves many new technologies and high requirements for the real-time capability and reliability. So process bus communication schemes of present stage are very wariness in practical engineering application and

Yong-hui Yi; Lei-tao Wang; Yong-jian Tao

2011-01-01

436

Performance of IEC 61850-9-2 Process Bus and Corrective Measure for Digital Relaying  

Microsoft Academic Search

International Electrotechnical Commission (IEC) standard 61850 proposes the Ethernet-based communication networks for protection and automation within the power sub- station. Major manufacturers are currently developing products for the process bus in compliance with IEC 61850 part 9-2. For the successful implementation of the IEC 61850-9-2 process bus, it is important to analyze the performance of time-critical mes- sages for the

Mitalkumar G. Kanabar; Tarlochan S. Sidhu

2011-01-01

437

Modeling multilayered PCB power-bus designs using an MPIE based circuit extraction technique  

Microsoft Academic Search

A circuit extraction tool (CEMPIE) has been developed based on the mixed-potential integral equation (MPIE) using a quasi-static approximation. A power-bus in a multi-layered PCB consisting of a pair of dedicated ground and power planes is studied using this tool. The distributed behavior of a power-bus is represented by a collection of passive circuit elements, which is valid up to

Hao Shi; Jun Fan; James L. Drewniak; Todd H. Hubing; Thomas P. Van Doren

1998-01-01

438

Transit Bus Operator Performance and Attitudes Toward a Collision Warning System: Results of a Simulator Experiment  

Microsoft Academic Search

Objective. This article discusses the results of a simulator experiment to examine the efficacy of a collision warning system for transit bus operators.Methods. Bus operators from a major metropolitan transit agency were assigned to one of three conditions: a collision warning system with a visual-only driver-vehicle interface, a collision warning system with a visual and auditory driver-vehicle interface, or no

Stephen J. Reinach; Jeffrey H. Everson

2005-01-01

439

Ergonomic work analysis of urban bus drivers in Rio de Janeiro city.  

PubMed

This article is the result of a case study on ergonomic work analysis carried out in an urban bus company located in Ilha do Governador, Rio de Janeiro. The methodology used in this work follows the French-tradition Ergonomic Analysis of the Work (EWA) combined with the best tradition from anglo-saxon ergonomic work analysis. The situated diagnosis was performed to provide relevant information about the work conditions of a bus driver. PMID:22317732

Querido, Aloá; Nogueira, Tainan; Gama, Rafael; Orlando, José

2012-01-01

440

Dual thyroid ectopia.  

PubMed

Ectopic thyroid gland is a rare embryological fault of thyroid development. Dual ectopic thyroid is even more rare and only 8 cases have been reported in the literature. The author presents a case of dual ectopic thyroid in a 16-year-old boy with an anterior neck mass, which is gradually growing in size particularly in the last 2 years. The initial diagnosis was thyroglossal duct cyst. Thyroid function test revealed elevated thyroid-stimulating hormone. Ultrasound of the neck did not show thyroid gland in its normal pretracheal position. Thyroid scan (Technetium 99) revealed the diagnosis of dual thyroid ectopia (lingual and subhyoid). PMID:12973493

Al-Akeely, Mohammed H

2003-09-01

441

Analysis of M/G/1 queueing model with state dependent arrival and vacation  

NASA Astrophysics Data System (ADS)

This investigation deals with single server queueing system wherein the arrival of the units follow Poisson process with varying arrival rates in different states and the service time of the units is arbitrary (general) distributed. The server may take a vacation of a fixed duration or may continue to be available in the system for next service. Using the probability argument, we construct the set of steady state equations by introducing the supplementary variable corresponding to elapsed service time. Then, we obtain the probability generating function of the units present in the system. Various performance indices, such as expected number of units in the queue and in the system, average waiting time, etc., are obtained explicitly. Some special cases are also deduced by setting the appropriate parameter values. The numerical illustrations are provided to carry out the sensitivity analysis in order to explore the effect of different parameters on the system performance measures.

Singh, Charan Jeet; Jain, Madhu; Kumar, Binay

2012-05-01

442

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

NASA Astrophysics Data System (ADS)

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

Romano, S.; Wimmer, R.

1993-02-01

443

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

SciTech Connect

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

Romano, S.; Wimmer, R.

1993-02-04

444

Efficiency-Driven Heavy-Traffic Approximations for Many-Server Queues with Abandonments  

Microsoft Academic Search

To provide useful practical insight into the performance of service-oriented (non-revenue- generating) call centers, which often provide low-to-moderate quality of service, this paper investigates the e-ciency-driven (ED) many-server heavy-tra-c limiting regime for queues with abandonments. Attention is focused on the M=M=s=r+M model, having a Poisson arrival process, exponential service times, s servers, r extra waiting spaces, exponential abandon times (the

Ward Whitt

2004-01-01

445

GI\\/M\\/1 Queue with Set-Up Period and Working Vacation and Vacation Interruption  

Microsoft Academic Search

In this paper, we consider a GI\\/M\\/1 queue with set-up period and working vacation and working interruption. We introduce set-up time and vacation interruption policy: the server can come back to the set-up period once there are customers after a service completion during the vacation period, thus the server may not accomplish vacation. Using matrix-geometric solution method, we obtain the

Guo-hui Zhao; Xin-xin Du; P. R. China; Nai-shuo Tian

446

Queue Size Determines the Width of Tunnels in the Formosan Subterranean Termite (Isoptera: Rhinotermitidae)  

Microsoft Academic Search

We present a model of tunnel excavation by termites that requires no pheromone labeling of soil or work sites, but instead\\u000a relies on tactile interactions and individuals who actively orient their movement. Potential termite excavators moved from\\u000a the tunnel origin towards the distal end of the tunnel and formed a queue behind those termites at the digging face. Delayed\\u000a termites

Paul M. Bardunias; Nan-Yao Su

2010-01-01

447

Power-law and exponential tails in a stochastic priority-based model queue  

NASA Astrophysics Data System (ADS)

We derive exact asymptotic results for a stochastic queueing model in which tasks are executed according to a continuous-valued priority. The distribution P(?) of the waiting times ? of executed tasks for this model is shown to behave asymptotically as a power law, P(?)˜?-3/2 , when the average rates of task arrival ? and execution ? satisfy ??? (as was earlier noted empirically). For ?>? , P(?)˜?-5/2exp[-(?-?)2?] .

Grinstein, G.; Linsker, R.

2008-01-01

448

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

449

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

450

Rainbow Fair Queueing: Fair Bandwidth Sharing Without Per-Flow State  

Microsoft Academic Search

Fair bandwidth sharing at routers has several advantages, includingprotection of well-behaved flows and possible simplification of endto-end congestion control mechanisms. Traditional mechanisms to achievefair sharing (e.g., Weighted Fair Queueing, Flow Random Early Discard)require per-flow state to determine which packets to drop under congestion,and therefore are complex to implement at the interior of a high-speednetwork. In recent work, Stoica et al.

Zhiruo Cao; Zheng Wang; Ellen W. Zegura

2000-01-01

451

Priority queue schedulers with approximate sorting in output-buffered switches  

Microsoft Academic Search

All recently proposed packet-scheduling algorithms for output-buffered switches that support quality-of-service (QoS) transmit packets in some priority order, e.g., according to deadlines, virtual finishing times, eligibility times, or other time stamps that are associated with a packet. Since maintaining a sorted priority queue introduces significant overhead, much emphasis on QoS scheduler design is put on methods to simplify the task

Jorg Liebeherr; Dallas E. Wrege

1999-01-01

452

PCS optical fibers for an automobile data bus  

NASA Astrophysics Data System (ADS)

Optical fibers have been used for data communications in automobiles for several years. The fiber of choice thus far has been a plastic core/plastic clad optical fiber (POF) consisting of the plastic polymethylmethacrylate (PMMA). The POF fiber provides a low cost fiber with relatively easy termination. However, increasing demands regarding temperature performance, transmission losses and bandwidth have pushed the current limits of the POF fiber, and the automotive industry is now moving towards an optical fiber with a silica glass core/plastic clad (PCS). PCS optical fibers have been used successfully in industrial, medical, sensor, military and data communications systems for over two decades. The PCS fiber is now being adapted specifically for automotive use. In the following, the design criteria and design alternatives for the PCS as well as optical, thermal, and mechanical testing results for key automotive parameters are described. The fiber design tested was 200&mum synthetic silica core/230&mum fluoropolymer cladding/1510&mum nylon buffer. Key attributes such as 700 - 900 nm spectral attenuation, 125°C thermal soak, -40 to 125°C thermal cycling, bending losses, mechanical strength, termination capability, and cost are discussed and compared. Overall, a specifically designed PCS fiber is expected to be acceptable for the use in an automotive data bus, and will show improvement in optical transmission, temperature range and bandwidth. However, the final selection of buffer and jacket materials and properties will be most dependent on the selection of a reliable and economical termination method.

Clarkin, James P.; Timmerman, Richard J.; Stolte, Gary W.; Klein, Karl-Friedrich

2005-02-01

453

An evaluation of comfort of a bus seat.  

PubMed

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

Jianghong, Z; Long, T

1994-12-01

454

Oxygen Generation System Laptop Bus Controller Flight Software  

NASA Technical Reports Server (NTRS)

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

Rowe, Chad; Panter, Donna

2009-01-01

455

Composite Bus Structure for the SMEX/WIRE Satellite  

NASA Technical Reports Server (NTRS)

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

Rosanova, Giulio G.

1998-01-01

456

Self-dual and quasi self-dual algebras.  

E-print Network

A self-dual algebras is one isomorphic as a module to the opposite of its dual; a quasi self-dual algebra is one whose cohomology with coefficients in itself is isomorphic to that with coefficients in the opposite of its dual. For these algebras, cohomology with coefficients in itself, which governs its deformation theory, is a contravariant functor of the algebra. Finite dimensional self-dual algebras over a field are identical with symmetric Frobenius algebras. (The monoidal category of commutative Frobenius algebras is known to be equivalent to that of 1+1 dimensional topological quantum field theories.) All finite poset algebras are quasi self-dual.

Murray Gerstenhaber

457

Smoking close to others and butt littering at bus stops: pilot observational study  

PubMed Central

Background. Transportation settings such as bus stops and train station platforms are increasingly the target for new smokefree legislation. Relevant issues include secondhand smoke exposure, nuisance, litter, fire risks and the normalization of smoking. We therefore aimed to pilot study aspects of smoking behavior and butt disposal at bus stops. Methods. Systematic observation of smoking and butt disposal by smokers at bus stops. The selection of 11 sites was a mix of convenience and purposeful (bus stops on main routes) in two New Zealand cities. Results. During 27 h of observation, a total of 112 lit cigarettes were observed being smoked. Smoking occurred in the presence of: just adults (46%), both young people and adults (44%), just young people (6%) and alone (5%). An average of 6.3 adults and 3.8 young people were present at the bus stops while smoking occurred, at average minimum distances of 1.7 and 2.2 m respectively. In bus stops that included an enclosed shelter, 33% of the cigarettes were smoked inside the shelter with others present. Littering was the major form of cigarette disposal with 84% of cigarettes smoked being littered (95% CI; 77%–90%). Also, 4% of disposals were into vegetation, which may pose a fire risk. Conclusions. This pilot study is limited by its small size and various methodological aspects but it appears to be a first attempt to provide observational evidence around smoking at bus stops. The issues described could be considered by policy makers who are investigating national smokefree laws or by-laws covering transportation settings. PMID:24688851

Oliver, Jane; Thomson, George

2014-01-01

458

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

SciTech Connect

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

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

1987-05-08

459

Teaching queueing theory with an inquiry-based learning approach: A case for applying webquest in a course in simulation and statistical analysis  

Microsoft Academic Search

This paper presents a case on applying WebQuest, a model for constructivist inquiry-based learning, to facilitate the teaching and learning of queueing theory. The author is a faculty member in an information engineering department, teaching an undergraduate course titled Simulation and Statistical Analysis in which queueing theory is a key topic. In this paper, the author shares her experience of

Yuen-Yan Chan

2007-01-01

460

Fault Location for Transmission Lines with Voltage and Current Measurements at One Bus  

NASA Astrophysics Data System (ADS)

This paper presents a novel fault location method for transmission lines. The proposed method extends an existing method to locate faults by employing voltage and current measurements at one bus, which can be the bus of the faulted line or be far away from the faulted line. The method is applicable if a loop exists that encloses the faulted line, and the bus, of which the voltage is used, and the branch, of which the current is used. The during-fault positive-sequence bus impedance matrix is derived. Then superimposed voltages and currents due to the fault are expressed as a function of fault location and related transfer and driving point impedances. Consequently, the fault location can be evaluated using the obtained measurements. The distributed parameter line model is adopted to consider the shunt capacitances of the line. The proposed method is independent of fault resistance and fault type. Simulation studies have been carried out based on a 27-bus power system, and promising results have been achieved.

Xiu, Wanjing; Liao, Yuan

2014-10-01

461

Implementation of Ada protocols on Mil-STD-1553 B data bus  

NASA Technical Reports Server (NTRS)

Standardization activity of data communication in avionic systems started in 1968 for the purpose of total system integration and the elimination of heavy wire bundles carrying signals between various subassemblies. The growing complexity of avionic systems is straining the capabilities of MIL-STD-1553 B (first issued in 1973), but a much greater challenge to it is posed by Ada, the standard language adopted for real-time, computer embedded-systems. Hardware implementation of Ada communication protocols in a contention/token bus or token ring network is proposed. However, during the transition period when the current command/response multiplex data bus is still flourishing and the development environment for distributed multi-computer Ada systems is as yet lacking, a temporary accomodation of the standard language with the standard bus could be very useful and even highly desirable. By concentrating all status informtion and decisions at the bus controller, it was found to be possible to construct an elegant and efficient harware impelementation of the Ada protocols at the bus interface. This solution is discussed.

Ruhman, Smil; Rosemberg, Flavia

1986-01-01

462

Design of bus-on-chip core for micro-satellite avionics  

NASA Astrophysics Data System (ADS)

This paper discusses a layout of bus-on-chip core referring to SoC thinking which is composed of six sections based on a physical chip of FPGA: multi-Processor cache coherence unit, external bus control module, TT&C module, Ethernet Mac interface, EDAC/DMA module, and AMBA bridges. Multi-processor cache coherence unit, as a key part of the bus core, is used to serve the rapid parallel computing by means of the breakthrough of write/read speed of EMS memory and enhances the reliability of OBC with the service of supporting the hot standby of redundancy and the reconfiguration of fault-tolerance. External bus control module is made to support the PnP of external components applying varieties of buses, which is designed by means of soft-core in order to adapt the variation of macro-design and improve the flexibility of external application. TT&C module is the interface of subsystems of telemetry, telecommand and communication, which involves the protocols of HDLC. Ethernet Mac interface based on TCP/IP acts as the access of ISL for formation flying, constellation, etc. EDAC/DMA module mainly manages the data exchange between AMBA bus and RAM, and assigns DMA for the payloads.

Liu, Youjun; You, Zheng; Li, Bin; Zhang, Xiangqi; Meng, Ziyang

2007-11-01

463

Self-dual supergravities  

NASA Astrophysics Data System (ADS)

The N-extended supersymmetric self-dual Poincaré supergravity equations provide a natural local description of supermanifolds possessing hyperkähler structure. These equations admit an economical formulation in chiral superspace. A reformulation in harmonic superspace encodes self-dual supervielbeins and superconnections in a graded skew-symmetric supermatrix superfield prepotential satisfying generalised Cauchy-Riemann conditions. A recipe is presented for extracting explicit self-dual supervielbeins and superconnections from such "analytic" prepotentials. We demonstrate the method by explicitly decoding a simple example of superfield prepotential, analogous to that corresponding to the Taub-NUT solution. The superspace we thus construct is an interesting N = 2 supersymmetric deformation of flat space, having flat "body" and constant curvature "soul".

Devchand, Ch.; Ogievetsky, V.

1995-02-01

464

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

NASA Astrophysics Data System (ADS)

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

Kempa, Wojciech M.

2010-10-01

465

Dual-Mode Combustor  

NASA Technical Reports Server (NTRS)

A new dual-mode ramjet combustor used for operation over a wide flight Mach number range is described. Subsonic combustion mode is usable to lower flight Mach numbers than current dual-mode scramjets. High speed mode is characterized by supersonic combustion in a free-jet that traverses the subsonic combustion chamber to a variable nozzle throat. Although a variable combustor exit aperture is required, the need for fuel staging to accommodate the combustion process is eliminated. Local heating from shock-boundary-layer interactions on combustor walls is also eliminated.

Trefny, Charles J (Inventor); Dippold, Vance F (Inventor)

2013-01-01

466

An impurity-induced gap system as a quantum data bus for quantum state transfer  

NASA Astrophysics Data System (ADS)

We introduce a tight-binding chain with a single impurity to act as a quantum data bus for perfect quantum state transfer. Our proposal is based on the weak coupling limit of the two outermost quantum dots to the data bus, which is a gapped system induced by the impurity. By connecting two quantum dots to two sites of the data bus, the system can accomplish a high-fidelity and long-distance quantum state transfer. Numerical simulations for finite system show that the numerical and analytical results of the effective coupling strength agree well with each other. Moreover, we study the robustness of this quantum communication protocol in the presence of disorder in the couplings between the nearest-neighbor quantum dots. We find that the gap of the system plays an important role in robust quantum state transfer.

Chen, Bing; Li, Yong; Song, Z.; Sun, C.-P.

2014-09-01

467

An evaluation plan of bus architectures and protocols using the NASA Ames intelligent redundant actuation system  

NASA Technical Reports Server (NTRS)

Means for evaluating data bus architectures and protocols for highly integrated flight control system applications are needed. Described are the criteria and plans to do this by using the NASA/Ames Intelligent Redundant Actuation System (IRAS) experimental set-up. Candidate bus architectures differ from one another in terms of: topology, access control, message transfer schemes, message characteristics, initialization. data flow control, transmission rates, fault tolerance, and time synchronization. The evaluation criteria are developed relative to these features. A preliminary, analytical evaluation of four candidate busses (MIL-STD-1553B, DATAC, Ethernet, and HSIS) is described. A bus must be exercised in a real-time environment to evaluate its dynamic characteristics. A plan for real-time evaluation of these four busses using a combination of hardware and simulation techniques is presented.

Defeo, P.; Chen, M.

1987-01-01

468

Experimental verification of PRD operation in CNG bus properties. Final report, November 1994--October 1995  

SciTech Connect

A review is presented of the experimental work continuing the failure analysis conducted by Thermo Power Corporation and Brooklyn Union on a temperature and pressure (disk fusible) relief device (PRD) manufactured by Mirada Research and Manufacturing Company. The study was stimulated by the recurrence of almost identical failures of the Mirada Generation III PRD that is in service on numerous compressed natural gas (CNG) bus properties throughout the United States. The field tests collected temperature data as actual buses were refueled. It was considered the only definitive means of determining whether the theory that a Joule-Thomson temperature depression, caused by a small orifice restriction in the Mirada shut off valve, was causing a thermal cycling of the PRD. Results of testing on two bus properties: Brooklyn Union`s Triboro Fleet and the Capital Metro bus fleet are presented in the appendixes.

Di Bella, F.; Neoh, S.

1996-07-01

469

Prototype crate and module system for a high speed top-mounted bus  

SciTech Connect

A prototype crate and module system, which uses the top surface of the modules both for mechanical support and for electrical connection to data and power buses, was built to evaluate its potential use in a fast ECL bus environment. Although the system was optimized for a wide, fast bus using transmission lines and emitter-coupled-logic buffers, the construction has advantages and economics which may make it useful in low-performance systems as well. Both the front and rear module ends are available for user controls and connections. The vertical size of the modules is independent of the bus mechanics. Modules can be inserted and removed from either the front or the rear of the rack. Construction details of the prototype are given. 8 figures.

Gustavson, D.B.

1978-10-01

470

Increasing throughput of multiplexed electrical bus in pipe-lined architecture  

DOEpatents

Techniques are disclosed for increasing the throughput of a multiplexed electrical bus by exploiting available pipeline stages of a computer or other system. For example, a method for increasing a throughput of an electrical bus that connects at least two devices in a system comprises introducing at least one signal hold stage in a signal-receiving one of the two devices, such that a maximum frequency at which the two devices are operated is not limited by a number of cycles of an operating frequency of the electrical bus needed for a signal to propagate from a signal-transmitting one of the two devices to the signal-receiving one of the two devices. Preferably, the signal hold stage introduced in the signal-receiving one of the two devices is a pipeline stage re-allocated from the signal-transmitting one of the two devices.

Asaad, Sameh; Brezzo, Bernard V; Kapur, Mohit

2014-05-27

471

IEEE 1394/firewire a low cost, high speed, digital serial bus  

SciTech Connect

Does the world need yet another 1/0 bus standard? If you need fast and cheap serial video communication, then the answer is yes. As technology advances, so too must data transport mechanisms advance. You can`t expect RS-232 to support real-time digital video, and if you can`t afford expensive professional serial video interfaces, (such as Sony`s Serial Digital Interface), Firewire may be a good solution. IEEE 1394, or commonly known as Firewire, is a general purpose serial bus that meets many of the 1/0 needs of today`s video and multimedia developers. For those of you who only read the first paragraph, here`s Firewire in a nutshell: It provides a guaranteed transfer rate of 10OMbps or 20OMbps of digital data (such as video direct from camera to computer), over an inexpensive, non-proprietary serial bus. Here is a list of its features.

Gaunt, R.

1997-05-01

472

The perception of pleasantness in a product of collective use: the bus shelter.  

PubMed

This article presents a study on the identification of a setting whose arrangement of attributes could lead to the perception of pleasantness of a bus shelter: a product that should welcome people while waiting for the bus. Two different bus shelters typologies in the city of Porto Alegre, state of Rio Grande do Sul, Brazil, were evaluated, where four attributes were under consideration. The relation between the shelters subject of the study and the surroundings was significant for defining the attributes. The setting with curve shaped cover, bench, rear wall, and surrounding vegetation was considered the most pleasant one. The seats and the rear wall were associated with the practical function of the product while the curve shaped cover and the surrounding vegetation were associated with the aesthetical function according to the participant users. PMID:22316736

Pizzato, Gabriela; Guimarães, Lia; ten Caten, Carla

2012-01-01

473

Self-reported low back symptoms in urban bus drivers exposed to whole-body vibration.  

PubMed

The prevalence of self-reported low back symptoms was investigated by a postal questionnaire in a group of 234 urban bus drivers exposed to whole-body vibration and postural stress and in a control group of 125 maintenance workers employed at the same bus municipal company. The average vertical whole-body vibration magnitude measured on the seat pan of the buses was 0.4 m/s2. After controlling for potential confounders, the prevalence odds ratios for the bus drivers compared to the controls significantly exceeded 1 for several types of low back symptoms (leg pain, acute low back pain, low back pain). The occurrence of low back symptoms increased with increasing whole-body vibration exposure expressed in terms of total (lifetime) vibration dose (years m2/s4), equivalent vibration magnitude (m/s2), and duration of exposure (years of service). The highest prevalence of disc protrusion was found among the bus drivers with more severe whole-body vibration exposure. Frequent awkward postures at work were also related to some types of low back symptoms. It is concluded that bus driving is associated with an increased risk for low back troubles. This excess risk may be due to both whole-body vibration exposure and prolonged sitting in a constrained posture. The findings of this study also indicated that among the bus drivers low back symptoms occurred at whole-body vibration exposure levels that were lower than the health-based exposure limits proposed by the International Standard ISO 2631/1. PMID:1411756

Bovenzi, M; Zadini, A

1992-09-01

474

Stochastic analyses arising from a new approach for closed queueing networks  

E-print Network

service distribution using the Cox-r (C r ) representation, a numerical solution was obtained by Marie [29] and Marie and Pellaumail [30] and provides a particularly efficient algorithm for Cox-2 and Erlang-r service processes. In addition, Marie [28...] proposed an approximate solution to general closed queueing networks, where each node is analyzed iteratively as a ?(n)/C r /1/N model. Stewart and Marie [44] and Willits [49] extended the previous model to include multiple servers. See Appendix A for a...

Sun, Feng

2009-05-15

475

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

E-print Network

-Newall-Gordon type [Daigle, 1992] was derived by Ho and Cao [1983]. They combined the PA formula with a discrete-event simulation and the result obtained from the simulation was compared with the analytical solution. 10 For a restricted class of parameters... approximation algorithm such as the R-M algorithm to optimize parameters for a single server queue in a single simulation run [Cao and Ho, 1987; Suri and Zazanis, 1988; Suri and Leung, 1989]. A gradient updating procedure, which used second derivatives...

Jeong, Ki-Young

2012-06-07

476

Prevalence of metabolic syndrome in bus and truck drivers in Kashan, Iran  

Microsoft Academic Search

Background  Bus and truck drivers are apparently more involved in metabolic syndrome and its complications due to their working conditions.\\u000a The related impacts are not only harmful for driver's health, but also may endanger others. The present research was carried\\u000a out to determine the prevalence of metabolic syndrome among bus and truck drivers in Kashan, a city in Iran.\\u000a \\u000a \\u000a \\u000a \\u000a Materials  In 2007,

Hamid R Saberi; Ali R Moravveji; Esmaeil Fakharian; Masoud Motalebi kashani; Ali R Dehdashti

2011-01-01

477

An EPR data system based on S-100 bus home computer components  

NASA Astrophysics Data System (ADS)

A technique for construction of a laboratory data system using commercially available S-100 (IEEE-696) bus components is described. An interface to an IBM/Broker ER-200 EPR spectrometer is also described. This interface could be used generally by any instrument which provides either analog or digital information for computer processing. The S-100 bus components are inexpensive and one is able to construct a complete data system at minimum cost. A final part of the article describes software which has been developed for processing EPR data

Schultz, R.; Hurst, G.; Thieret, T. E.; Kreilick, R. W.

478

Common mode noise on the main Tevatron bus and associated beam emittance growth  

SciTech Connect

Overlap of betatron tune frequencies with the power supply noise spectrum can cause transverse beam emittance growth in a storage ring. We have studied this effect for tunes near the integer, where the betatron frequency is low. By injecting noise onto the main power supply bus, it was determined that common mode noise was the dominant source of emittance growth. A noise suppression feed-back loop was then used to reduce the noise and the emittance growth. These experiments are described as are investigations of the common mode propagation along the Tevatron bus and measurements of the fields generated by common mode excitation of isolated Tevatron magnets. 3 refs., 4 figs.

Zhang, P.; Johnson, R.P.; Kuchnir, M.; Siergiej, D.; Wolff, D.

1991-05-01

479

The Health Service Bus: an architecture and case study in achieving interoperability in healthcare.  

PubMed

Interoperability in healthcare is a requirement for effective communication between entities, to ensure timely access to up to-date patient information and medical knowledge, and thus facilitate consistent patient care. An interoperability framework called the Health Service Bus (HSB), based on the Enterprise Service Bus (ESB) middleware software architecture is presented here as a solution to all three levels of interoperability as defined by the HL7 EHR Interoperability Work group in their definitive white paper "Coming to Terms". A prototype HSB system was implemented based on the Mule Open-Source ESB and is outlined and discussed, followed by a clinically-based example. PMID:20841819

Ryan, Amanda; Eklund, Peter

2010-01-01

480

New Dual Quark Models  

Microsoft Academic Search

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

K. Bardakci; M. B. Halpern

1971-01-01

481

Dual beam optical interferometer  

NASA Technical Reports Server (NTRS)

A dual beam interferometer device is disclosed that enables moving an optics module in a direction, which changes the path lengths of two beams of light. The two beams reflect off a surface of an object and generate different speckle patterns detected by an element, such as a camera. The camera detects a characteristic of the surface.

Gutierrez, Roman C. (Inventor)

2003-01-01

482

Visual and Operational Impacts of Variable Speed Limit Signs on Bus Drivers on Freeways Using Driving Simulator  

Microsoft Academic Search

The benefits of variable speed limit signs (VSLS) include preventing drivers from rear-end collisions and maintaining a stable traffic flow on roads. However, the configurations of VSLS will directly or indirectly affect driverspsila recognition to VSLS systems and then influence their driving behavior. Since bus passenger occupancy is much higher than that of a small passenger car, a bus accident

Chien-Yen Chang; Chai-Chun Li

2008-01-01

483

Comparative study of the FireWire™ IEEE1394 protocol with the Universal Serial Bus and Ethernet  

Microsoft Academic Search

This paper presents results of study of the IEEE 1394 protocol, which is the IEEE standard for a high performance serial bus with similar, and more widely used technologies like the Universal Serial Bus 1.0 and the Ethernet Protocol. A thorough theoretical and experimental investigation between the technologies is made with respect to the actual architecture of the buses and

G. Ramamurthy; K. Ashenayi

2002-01-01

484

Practical experience with IEEE 1588 high Precision Time Synchronization in electrical substation based on IEC 61850 Process Bus  

Microsoft Academic Search

This paper describes the experience from the world first installation of High Voltage substation with IEC 61850 Process Bus where IEEE 1588 Time Synchronization and dynamic multicast filtering have been used. The authors provide brief introduction to the concept of digital substation and process bus, then provide overview of IEEE 1588 standard for precise time synchronization and finally describe the

R. Moore; R. Midence; M. Goraj

2010-01-01

485

A Member of The Texas A&M University System Reducing School Bus Stop-Arm Violations in Texas  

E-print Network

A Member of The Texas A&M University System Reducing School Bus Stop-Arm Violations in Texas-ARM VIOLATIONS IN TEXAS Pilot Test Results for the Application and Effectiveness of Digital Video Technology in Identifying School Bus Stop-Arm Violations By Patricia A. Turner Associate Research Scientist Texas

486

Convergence acceleration and accuracy improvement in power bus impedance calculation with a fast algorithm using cavity modes  

Microsoft Academic Search

Based on the cavity-mode model, we have developed a fast algorithm for calculating power bus impedance in multilayer printed circuit boards. The fast algorithm is based on a closed-form expression for the impedance Z matrix of a rectangular power bus structure; this expression was obtained by reducing the original double infinite series into a single infinite series under an approximation.

Zhi Liang Wang; Osami Wada; Yoshitaka Toyota; Ryuji Koga

2005-01-01

487

49 CFR 1331.5 - Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus.  

Code of Federal Regulations, 2014 CFR

...Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus...Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus...Failure to do so will result in lack of immunity for that activity. (b) The...

2014-10-01

488

49 CFR 1331.5 - Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus.  

Code of Federal Regulations, 2011 CFR

...Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus...Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus...Failure to do so will result in lack of immunity for that activity. (b) The...

2011-10-01

489

49 CFR 1331.5 - Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus.  

Code of Federal Regulations, 2010 CFR

...Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus...Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus...Failure to do so will result in lack of immunity for that activity. (b) The...

2010-10-01

490

49 CFR 1331.5 - Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus.  

Code of Federal Regulations, 2012 CFR

...Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus...Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus...Failure to do so will result in lack of immunity for that activity. (b) The...

2012-10-01

491

49 CFR 1331.5 - Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus.  

Code of Federal Regulations, 2013 CFR

...Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus...Additional standards for retaining antitrust immunity by passenger bus industry rate bureaus...Failure to do so will result in lack of immunity for that activity. (b) The...

2013-10-01

492

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

Code of Federal Regulations, 2012 CFR

...2012-04-01 2011-04-01 true How does a school calculate annual bus transportation miles...THE INTERIOR EDUCATION THE INDIAN SCHOOL EQUALIZATION PROGRAM Student Transportation...Transportation Miles § 39.711 How does a school calculate annual bus transportation...

2012-04-01

493

Math. 55 Waiting for a Bus April 12, 1999 11:44 am Prof. W. Kahan Page 1  

E-print Network

Math. 55 Waiting for a Bus April 12, 1999 11:44 am Prof. W. Kahan Page 1 How long can one expect and other contingencies introduce unavoidable variations in schedules. Let w minutes be the intended waiting expect to wait for w/2 minutes until the next bus arrived. This figure w/2 is the average waiting time

California at Berkeley, University of

494

Assessment on the occupational exposure of urban public bus drivers to bioaccessible trace metals through resuspended fraction of settled bus dust.  

PubMed

Limited information is available on the bioaccessible fraction of trace metals in the resuspended fraction of settled bus dust in order to estimate bus drivers' occupational exposure. In this study, 45 resuspended fraction of settled dust samples were collected from gasoline and compressed natural gas (CNG) powered buses and analyzed for trace metals and their fraction concentrations using a three-step sequential extraction procedure. Experimental results showed that zinc (Zn) had the greatest bioaccessible fraction, recorded as an average of 608.53mg/kg, followed in order of decreasing concentration by 129.80mg/kg lead (Pb), 56.77mg/kg copper (Cu), 34.03mg/kg chromium (Cr), 22.05mg/kg nickel (Ni), 13.17mg/kg arsenic (As) and 2.77mg/kg cadmium (Cd). Among the three settled bus dust exposure pathways, ingestion was the main route. Total exposure hazard index (HIt) for non-carcinogenic effect trace metals was lower than the safety level of 1. The incremental lifetime cancer risk (ILCR) for drivers was estimated for trace metal exposure. Pb and Ni presented relatively high potential risks in the non-carcinogenic and potentially carcinogenic health assessment for all drivers. ILCR was in the range of 1.84E-05 to 7.37E-05 and 1.74E-05 to 6.95E-05 for gasoline and CNG buses, respectively. PMID:25437951

Gao, Peng; Liu, Sa; Ye, Wenyuan; Lin, Nan; Meng, Ping; Feng, Yujie; Zhang, Zhaohan; Cui, Fuyi; Lu, Binyu; Xing, Baoshan

2015-03-01

495

J. of Electromagn. Waves and Appl., Vol. 22, 13711379, 2008 DUAL BAND DUAL POLARIZED ANTENNA WITH  

E-print Network

J. of Electromagn. Waves and Appl., Vol. 22, 1371­1379, 2008 DUAL BAND DUAL POLARIZED ANTENNA&MMWAVES Company Malaysia Abstract--In this paper new array element for use in dual band dual polarized antenna band band and dual polarized antenna has been observed. Some designs for dual band and dual polarized

Boyer, Edmond

496

A Priority Queue Model of Human Dynamics with Bursty Input Tasks  

NASA Astrophysics Data System (ADS)

The physics of human activities recently has been studied in the view point that they are dynamic processes of a complex system. The studies reveal that the human activities have bursty nature - occasional abrupt bursts of activity level for short periods of time, along with long periods of inactivity. Quantitative studies show that the distribution of the time, ?, between two consecutive activity events exhibits a power-law behavior with universal exponents ~? - 1.5 or ~? - 1.0. Such universal behaviors were explained by the universality in the waiting-time distribution of tasks in model queue systems, which operate based on priority. In the models, the rates of task input are presumed to follow a Poisson-type distribution. An empirical observation of human activities, however, shows that the task arriving rate for some people also has bursty nature - the number of tasks arrive to the people follows a power-law distribution. In this paper, a new model queue system for this case is introduced and studied by analytic and numerical methods. The waiting-time distribution for the new model is found also to follow a power law, but the exponent varies according to the parameters of the model and takes other values than 1.5 or 1.0. The analytic solution is obtained via the generating function formalism, different from the biased random walk approach used in the previous studies.

Kim, Jin Seop; Masuda, Naoki; Kahng, Byungnam

497

Tutorial in medical decision modeling incorporating waiting lines and queues using discrete event simulation.  

PubMed

In most decision-analytic models in health care, it is assumed that there is treatment without delay and availability of all required resources. Therefore, waiting times caused by limited resources and their impact on treatment effects and costs often remain unconsidered. Queuing theory enables mathematical analysis and the derivation of several performance measures of queuing systems. Nevertheless, an analytical approach with closed formulas is not always possible. Therefore, simulation techniques are used to evaluate systems that include queuing or waiting, for example, discrete event simulation. To include queuing in decision-analytic models requires a basic knowledge of queuing theory and of the underlying interrelationships. This tutorial introduces queuing theory. Analysts and decision-makers get an understanding of queue characteristics, modeling features, and its strength. Conceptual issues are covered, but the emphasis is on practical issues like modeling the arrival of patients. The treatment of coronary artery disease with percutaneous coronary intervention including stent placement serves as an illustrative queuing example. Discrete event simulation is applied to explicitly model resource capacities, to incorporate waiting lines and queues in the decision-analytic modeling example. PMID:20345550

Jahn, Beate; Theurl, Engelbert; Siebert, Uwe; Pfeiffer, Karl-Peter

2010-01-01

498

Handover Management for VoWLAN Based on Estimation of AP Queue Length and Frame Retries  

NASA Astrophysics Data System (ADS)

Switching a communication path from one Access Point (AP) to another in inter-domain WLANs is a critical challenge for delay-sensitive applications such as Voice over IP (VoIP) because communication quality during handover (HO) is more likely to be deteriorated. To maintain VoIP quality during HO, we need to solve many problems. In particular, in bi-directional communication such as VoIP, an AP becomes a bottleneck with the increase of VoIP calls. As a result, packets queued in the AP buffer may experience a large queuing delay or packet losses due to increase in queue length or buffer overflow, thereby causing the degradation of VoIP quality for the Mobile Nodes (MNs) side. To avoid this degradation, MNs need to appropriately and autonomously execute HO in response to the change in wireless network condition, i.e., the deterioration of wireless link quality and the congestion state at the AP. In this paper, we propose an HO decision strategy considering frame retries, AP queue length, and transmission rate at an MN for maintaining VoIP quality during HO. Through simulation experiments, we then show that our proposed method can maintain VoIP quality during HO by properly detecting the wireless network condition.

Niswar, Muhammad; Kashihara, Shigeru; Tsukamoto, Kazuya; Kadobayashi, Youki; Yamaguchi, Suguru

499

Reproductive queue without overt conflict in the primitively eusocial wasp Ropalidia marginata  

PubMed Central

Colonies of the primitively eusocial wasp Ropalidia marginata consist of a single egg layer (queen) and a number of non–egg-laying workers. Although the queen is a docile individual, not at the top of the behavioral dominance hierarchy of the colony, she maintains complete reproductive monopoly. If the queen is lost or removed, one and only one of the workers [potential queen (PQ)] becomes hyperaggressive and will become the next queen of the colony. The PQ is almost never challenged because she first becomes hyperaggressive and then gradually loses her aggression, develops her ovaries, and starts laying eggs. Although we are unable to identify the PQ when the queen is present, she appears to be a “cryptic heir designate.” Here, we show that there is not just one heir designate but a long reproductive queue and that PQs take over the role of egg-laying, successively, without overt conflict, as the queen or previous PQs are removed. The dominance rank of an individual is not a significant predictor of its position in the succession hierarchy. The age of an individual is a significant predictor, but it is not a perfect predictor because PQs often bypass older individuals to become successors. We suggest that such a predesignated reproductive queue that is implemented without overt conflict is adaptive in the tropics, where conspecific usurpers from outside the colony, which can take advantage of the anarchy prevailing in a queenless colony and invade it, are likely to be present throughout the year. PMID:22908278

Bang, Alok; Gadagkar, Raghavendra

2012-01-01

500

Latent heat storage modules for preheating internal combustion engines: application to a bus petrol engine  

Microsoft Academic Search

The heat storage (HS) system for pre-heating a bus petrol engine before its ignition was mathematically modelled and experimentally investigated. The development of such devices is an extremely urgent problem especially for regions with a cold climate. HS system working on the effect of absorption and rejection of heat during the solid-liquid phase change of HS material is realised, tested

L. L. Vasiliev; V. S. Burak; A. G. Kulakov; D. A. Mishkinis; P. V. Bohan

2000-01-01