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

PubMed

Chen, Qun

2015-01-01

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

Digital Autonomous Terminal Access Communication (DATAC) system

NASA Technical Reports Server (NTRS)

Novacki, Stanley M., III

1987-01-01

In order to accommodate the increasing number of computerized subsystems aboard today's more fuel efficient aircraft, the Boeing Co. has developed the DATAC (Digital Autonomous Terminal Access Control) bus to minimize the need for point-to-point wiring to interconnect these various systems, thereby reducing total aircraft weight and maintaining an economical flight configuration. The DATAC bus is essentially a local area network providing interconnections for any of the flight management and control systems aboard the aircraft. The task of developing a Bus Monitor Unit was broken down into four subtasks: (1) providing a hardware interface between the DATAC bus and the Z8000-based microcomputer system to be used as the bus monitor; (2) establishing a communication link between the Z8000 system and a CP/M-based computer system; (3) generation of data reduction and display software to output data to the console device; and (4) development of a DATAC Terminal Simulator to facilitate testing of the hardware and software which transfer data between the DATAC's bus and the operator's console in a near real time environment. These tasks are briefly discussed.

Analyzing the effects of transit network change on agency performance and riders in a decentralized, small-to-mid-sized US metropolitan area : a case study of Tallahassee, Florida.

DOT National Transportation Integrated Search

2013-05-01

On July 11, 2011, StarMetro, the local public transit agency in Tallahassee, Florida, restructured its entire bus network from a : downtown-focused radial system to a decentralized, grid-like system that local officials and agency leaders believed wo...

The high speed interconnect system architecture and operation

NASA Astrophysics Data System (ADS)

Anderson, Steven C.

The design and operation of a fiber-optic high-speed interconnect system (HSIS) being developed to meet the requirements of future avionics and flight-control hardware with distributed-system architectures are discussed. The HSIS is intended for 100-Mb/s operation of a local-area network with up to 256 stations. It comprises a bus transmission system (passive star couplers and linear media linked by active elements) and network interface units (NIUs). Each NIU is designed to perform the physical, data link, network, and transport functions defined by the ISO OSI Basic Reference Model (1982 and 1983) and incorporates a fiber-optic transceiver, a high-speed protocol based on the SAE AE-9B linear token-passing data bus (1986), and a specialized application interface unit. The operating modes and capabilities of HSIS are described in detail and illustrated with diagrams.

Spatial analysis of bus transport networks using network theory

NASA Astrophysics Data System (ADS)

Shanmukhappa, Tanuja; Ho, Ivan Wang-Hei; Tse, Chi Kong

2018-07-01

In this paper, we analyze the bus transport network (BTN) structure considering the spatial embedding of the network for three cities, namely, Hong Kong (HK), London (LD), and Bengaluru (BL). We propose a novel approach called supernode graph structuring for modeling the bus transport network. A static demand estimation procedure is proposed to assign the node weights by considering the points of interests (POIs) and the population distribution in the city over various localized zones. In addition, the end-to-end delay is proposed as a parameter to measure the topological efficiency of the bus networks instead of the shortest distance measure used in previous works. With the aid of supernode graph representation, important network parameters are analyzed for the directed, weighted and geo-referenced bus transport networks. It is observed that the supernode concept has significant advantage in analyzing the inherent topological behavior. For instance, the scale-free and small-world behavior becomes evident with supernode representation as compared to conventional or regular graph representation for the Hong Kong network. Significant improvement in clustering, reduction in path length, and increase in centrality values are observed in all the three networks with supernode representation. The correlation between topologically central nodes and the geographically central nodes reveals the interesting fact that the proposed static demand estimation method for assigning node weights aids in better identifying the geographically significant nodes in the network. The impact of these geographically significant nodes on the local traffic behavior is demonstrated by simulation using the SUMO (Simulation of Urban Mobility) tool which is also supported by real-world empirical data, and our results indicate that the traffic speed around a particular bus stop can reach a jammed state from a free flow state due to the presence of these geographically important nodes. A comparison of the simulation and the empirical data provides useful information on how bus operators can better plan their routes and deploy stops considering the geographically significant nodes.

Multi-Antenna Data Collector for Smart Metering Networks with Integrated Source Separation by Spatial Filtering

NASA Astrophysics Data System (ADS)

Quednau, Philipp; Trommer, Ralph; Schmidt, Lorenz-Peter

2016-03-01

Wireless transmission systems in smart metering networks share the advantage of lower installation costs due to the expandability of separate infrastructure but suffer from transmission problems. In this paper the issue of interference of wireless transmitted smart meter data with third party systems and data from other meters is investigated and an approach for solving the problem is presented. A multi-channel wireless m-bus receiver was developed to separate the desired data from unwanted interferers by spatial filtering. The according algorithms are presented and the influence of different antenna types on the spatial filtering is investigated. The performance of the spatial filtering is evaluated by extensive measurements in a realistic surrounding with several hundreds of active wireless m-bus transponders. These measurements correspond to the future environment for data-collectors as they took place in rural and urban areas with smart gas meters equipped with wireless m-bus transponders installed in almost all surrounding buildings.

Scaling and correlations in three bus-transport networks of China

NASA Astrophysics Data System (ADS)

Xu, Xinping; Hu, Junhui; Liu, Feng; Liu, Lianshou

2007-01-01

We report the statistical properties of three bus-transport networks (BTN) in three different cities of China. These networks are composed of a set of bus lines and stations serviced by these. Network properties, including the degree distribution, clustering and average path length are studied in different definitions of network topology. We explore scaling laws and correlations that may govern intrinsic features of such networks. Besides, we create a weighted network representation for BTN with lines mapped to nodes and number of common stations to weights between lines. In such a representation, the distributions of degree, strength and weight are investigated. A linear behavior between strength and degree s(k)∼k is also observed.

Network integration modelling of feeder and BRT(bus rapid transit) to reduce the usage of private vehicles in Palembang’s suburban area

NASA Astrophysics Data System (ADS)

Nur'afalia, D.; Afifa, F.; Rubianto, L.; Handayeni, K. D. M. E.

2018-01-01

The aim of this research is to determine the optimal feeder network route that integrates with BRT (Bus Rapid Transit). Palembang, a high growing population city with unresolved transportation demand sector. BRT as main public transportation could not fulfill people’s demand in transportation, especially in Alang-Alang Lebar sub-district. As an impact, the usage of private vehicles increases along the movement toward the city center. The concept of Network Integration that integrates feeder network with BRT is expected to be a solution to suppress the rate of private vehicles’ usage and to improve public transportation service, so that the use of BRT will be increased in the suburban area of Palembang. The method used to identifying the optimal route using Route Analysis method is route analysis using Tranetsim 0.4. The best route is obtained based on 156 movement samples. The result is 58,7% from 199 mobility’s potency of private vehicle usage’s can be reduced if there is a feeder network’s route in Alang-Alang Lebar’s sub-district. From the result, the existance of integration between feeder network and BRT is potential enough to reduce the usage of private vehicles and supports the sustainability of transportation mobility in Palembang City.

Analysis of Feeder Bus Network Design and Scheduling Problems

PubMed Central

Almasi, Mohammad Hadi; Karim, Mohamed Rehan

2014-01-01

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

The NASA bus communications listening device software

NASA Technical Reports Server (NTRS)

Allen, M. A.

1979-01-01

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

Modular sensor network node

DOEpatents

Davis, Jesse Harper Zehring [Berkeley, CA; Stark, Jr., Douglas Paul; Kershaw, Christopher Patrick [Hayward, CA; Kyker, Ronald Dean [Livermore, CA

2008-06-10

A distributed wireless sensor network node is disclosed. The wireless sensor network node includes a plurality of sensor modules coupled to a system bus and configured to sense a parameter. The parameter may be an object, an event or any other parameter. The node collects data representative of the parameter. The node also includes a communication module coupled to the system bus and configured to allow the node to communicate with other nodes. The node also includes a processing module coupled to the system bus and adapted to receive the data from the sensor module and operable to analyze the data. The node also includes a power module connected to the system bus and operable to generate a regulated voltage.

Research on Some Bus Transport Networks with Random Overlapping Clique Structure

NASA Astrophysics Data System (ADS)

Yang, Xu-Hua; Wang, Bo; Wang, Wan-Liang; Sun, You-Xian

2008-11-01

On the basis of investigating the statistical data of bus transport networks of three big cities in China, we propose that each bus route is a clique (maximal complete subgraph) and a bus transport network (BTN) consists of a lot of cliques, which intensively connect and overlap with each other. We study the network properties, which include the degree distribution, multiple edges' overlapping time distribution, distribution of the overlap size between any two overlapping cliques, distribution of the number of cliques that a node belongs to. Naturally, the cliques also constitute a network, with the overlapping nodes being their multiple links. We also research its network properties such as degree distribution, clustering, average path length, and so on. We propose that a BTN has the properties of random clique increment and random overlapping clique, at the same time, a BTN is a small-world network with highly clique-clustered and highly clique-overlapped. Finally, we introduce a BTN evolution model, whose simulation results agree well with the statistical laws that emerge in real BTNs.

Application of new electro-optic technology to Space Station Freedom data management system

NASA Technical Reports Server (NTRS)

Husbands, C. R.; Girard, M. M.

1993-01-01

A low risk design methodology to permit the local bus structures to support increased data carrying capacities and to speed messages and data flow between nodes or stations on the Space Station Freedom Data Management System in anticipation of growing requirements was evaluated and recommended. The recommended design employs a collateral fiber optic technique that follows a NATO avionic standard that is developed, tested, and available. Application of this process will permit a potential 25 fold increase in data transfer performance on the local wire bus network with a fiber optic network, maintaining the functionality of the low-speed bus and supporting all of the redundant transmission and fault detection capabilities designed into the existing system. The application of wavelength division multiplexing (WDM) technology to both the local data bus and global data bus segments of the Data Management System to support anticipated additional highspeed data transmission requirements was also examined. Techniques were examined to provide a dual wavelength implementation of the fiber optic collateral networks. This dual wavelength implementation would permit each local bus to support two simultaneous high-speed transfers on the same fiber optic bus structure and operate within the limits of the existing protocol standard. A second WDM study examined the use of spectral sliced technology to provide a fourfold increase in the Fiber Distributed Data Interface (FDDI) global bus networks without requiring modifications to the existing installed cable plant. Computer simulations presented indicated that this data rate improvement can be achieved with commercially available optical components.

The ISES: A non-intrusive medium for in-space experiments in on-board information extraction

NASA Technical Reports Server (NTRS)

Murray, Nicholas D.; Katzberg, Stephen J.; Nealy, Mike

1990-01-01

The Information Science Experiment System (ISES) represents a new approach in applying advanced systems technology and techniques to on-board information extraction in the space environment. Basically, what is proposed is a 'black box' attached to the spacecraft data bus or local area network. To the spacecraft the 'black box' appears to be just another payload requiring power, heat rejection, interfaces, adding weight, and requiring time on the data management and communication system. In reality, the 'black box' is a programmable computational resource which eavesdrops on the data network, taking and producing selectable, real-time science data back on the network. This paper will present a brief overview of the ISES Concept and will discuss issues related to applying the ISES to the polar platform and Space Station Freedom. Critical to the operation of ISES is the viability of a payload-like interface to the spacecraft data bus or local area network. Study results that address this question will be reviewed vis-a-vis the solar platform and the core space station. Also, initial results of processing science and other requirements for onboard, real-time information extraction will be presented with particular emphasis on the polar platform. Opportunities for a broader range of applications on the core space station will also be discussed.

Local Area Networking Handbook

DTIC Science & Technology

1990-06-01

Number of dcvices IO’s-lOOO’s 10’s. I00Ys W0"s-10O’s supported Attachment cost S500-S50U) S40k-$ 56k S250-SIOOU C. LOCAL AREA NETWORKS Due to the...broadband cable by substituting RF modems for the conventional modems or line drivers. Then control may be imposed through conventional communications link...Ref. 11:p. 33] In a typical broadband bus configuration using FDM, channels are allocated dynamically, using frequency agile RF modems , rather than

Combined Simulated Annealing and Genetic Algorithm Approach to Bus Network Design

NASA Astrophysics Data System (ADS)

Liu, Li; Olszewski, Piotr; Goh, Pong-Chai

A new method - combined simulated annealing (SA) and genetic algorithm (GA) approach is proposed to solve the problem of bus route design and frequency setting for a given road network with fixed bus stop locations and fixed travel demand. The method involves two steps: a set of candidate routes is generated first and then the best subset of these routes is selected by the combined SA and GA procedure. SA is the main process to search for a better solution to minimize the total system cost, comprising user and operator costs. GA is used as a sub-process to generate new solutions. Bus demand assignment on two alternative paths is performed at the solution evaluation stage. The method was implemented on four theoretical grid networks of different size and a benchmark network. Several GA operators (crossover and mutation) were utilized and tested for their effectiveness. The results show that the proposed method can efficiently converge to the optimal solution on a small network but computation time increases significantly with network size. The method can also be used for other transport operation management problems.

Network device interface for digitally interfacing data channels to a controller a via network

NASA Technical Reports Server (NTRS)

Konz, Daniel W. (Inventor); Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Winkelmann, Joseph P. (Inventor)

2006-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. In one embodiment, the bus controller transmits messages to the network device interface containing a plurality of bits having a value defined by a transition between first and second states in the bits. The network device interface determines timing of the data sequence of the message and uses the determined timing to communicate with the bus controller.

Use of small stand-alone Internet nodes as a distributed control system

NASA Astrophysics Data System (ADS)

Goodwin, Robert W.; Kucera, Michael J.; Shea, Michael F.

1994-12-01

For several years, the standard model for accelerator control systems has been workstation consoles connected to VME local stations by a Local Area Network with analog and digital data being accessed via a field bus to custom I/O interface electronics. Commercially available hardware has now made it possible to implement a small stand-alone data acquisition station that combines the LAN connection, the computer, and the analog and digital I/O interface on a single board. This eliminates the complexity of a field bus and the associated proprietary I/O hardware. A minimum control system is one data acquisition station and a Macintosh or workstation console, both connected to the network; larger systems have more consoles and nodes. An implementation of this architecture is described along with performance and operational experience.

Sensor/Transducer Bus Alternatives for Space derived from Automotive Networks

NASA Astrophysics Data System (ADS)

Heyer, H.-V.

2004-06-01

Both automotive and space industry have major constraints concerning cable and harness. As in a satellite, the dry mass of the harness in the empty car is about 3.3% of the total car mass and the harness costs are about 12% of the total production cost. So a lot of new architectural communication and power distribution concepts are needed to reduce these drawbacks. One of the possible solutions is the use of distributed bus systems which contains in a decentralized topology busses such as CAN, TTCAN or FLEX-RAY for hard-real-time applications, MOST for fast video communication via optical fiber cabling and fire wire IEEE1394 as backbone.For the general purpose sensor/actuator tasks a simple robust one-wire bus has been defined, the Local Interconnect Network (LIN) bus. This bus is an open standard which is supported by several semiconductor manufactures. The bus was firstly introduced in 1999 and has now reached an acceptable maturity with version 2.0 turning out to be quite interesting as sensor / transducer bus for space applications.This presentation will focus on the LIN Bus and present an overview of that bus.

The Construction of Infrastructure for Library's Digital Document Telecommunications.

ERIC Educational Resources Information Center

Changxing, Ying; Zuzao, Lin

This paper discusses the construction of the infrastructure for libraries' digital document telecommunications. The first section describes the topologies of the library LAN (Local Area Network) cabling system, including the main characteristics of the LAN and three classical topologies typically used with LANs, i.e., the bus, star, and ring…

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Konz, Daniel W. (Inventor); Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Winkelmann, Joseph P. (Inventor)

2006-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted into digital signals and transmitted back to the controller. In one embodiment, the bus controller sends commands and data a defined bit rate, and the network device interface senses this bit rate and sends data back to the bus controller using the defined bit rate.

Identifying hub stations and important lines of bus networks: A case study in Xiamen, China

NASA Astrophysics Data System (ADS)

Zhang, Hui; Zhuge, Chengxiang; Yu, Xiaohua

2018-07-01

Hub stations and important lines play key roles in transfers between stations. In this paper, a node failure model is proposed to identify hub stations. In the model, we introduce two new indicators called neighborhood degree ratio and transfer index to evaluate the importance of stations, which consider neighborhood stations' degree of station and the initial transfer times between stations. Moreover, line accessibility is developed to measure the importance of lines in the bus network. Xiamen bus network in 2016 is utilized to test the model. The results show that the two introduced indicators are more effective to identify hub stations compared with traditional complex network indicators such as degree, clustering coefficient and betweenness.

AERIS--applications for the environment : real-time information synthesis state-of-the-practice support : state-of-the-practice assessment of technology to enable environmental data acquisition.

DOT National Transportation Integrated Search

2011-06-21

In this report, vehicle-based and infrastructure-based data acquisition technologies are assessed. Vehicle-based technologies include methods for accessing the Controller Area Network (CAN) Bus on heavy vehicles, the On-Board Diagnostic (OBD II) on s...

A study of topologies and protocols for fiber optic local area network

NASA Technical Reports Server (NTRS)

Yeh, C.; Gerla, M.; Rodrigues, P.

1985-01-01

The emergence of new applications requiring high data traffic necessitates the development of high speed local area networks. Optical fiber is selected as the transmission medium due to its inherent advantages over other possible media and the dual optical bus architecture is shown to be the most suitable topology. Asynchronous access protocols, including token, random, hybrid random/token, and virtual token schemes, are developed and analyzed. Exact expressions for insertion delay and utilization at light and heavy load are derived, and intermediate load behavior is investigated by simulation. A new tokenless adaptive scheme whose control depends only on the detection of activity on the channel is shown to outperform round-robin schemes under uneven loads and multipacket traffic and to perform optimally at light load. An approximate solution to the queueing delay for an oscillating polling scheme under chaining is obtained and results are compared with simulation. Solutions to the problem of building systems with a large number of stations are presented, including maximization of the number of optical couplers, and the use of passive star/bus topologies, bridges and gateways.

Electrical Design and Evaluation of Asynchronous Serial Bus Communication Network of 48 Sensor Platform LSIs with Single-Ended I/O for Integrated MEMS-LSI Sensors.

PubMed

Shao, Chenzhong; Tanaka, Shuji; Nakayama, Takahiro; Hata, Yoshiyuki; Muroyama, Masanori

2018-01-15

For installing many sensors in a limited space with a limited computing resource, the digitization of the sensor output at the site of sensation has advantages such as a small amount of wiring, low signal interference and high scalability. For this purpose, we have developed a dedicated Complementary Metal-Oxide-Semiconductor (CMOS) Large-Scale Integration (LSI) (referred to as "sensor platform LSI") for bus-networked Micro-Electro-Mechanical-Systems (MEMS)-LSI integrated sensors. In this LSI, collision avoidance, adaptation and event-driven functions are simply implemented to relieve data collision and congestion in asynchronous serial bus communication. In this study, we developed a network system with 48 sensor platform LSIs based on Printed Circuit Board (PCB) in a backbone bus topology with the bus length being 2.4 m. We evaluated the serial communication performance when 48 LSIs operated simultaneously with the adaptation function. The number of data packets received from each LSI was almost identical, and the average sampling frequency of 384 capacitance channels (eight for each LSI) was 73.66 Hz.

TMS communications hardware. Volume 2: Bus interface unit

NASA Technical Reports Server (NTRS)

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

1979-01-01

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

Bus-based park-and-ride system: a stochastic model on multimodal network with congestion pricing schemes

NASA Astrophysics Data System (ADS)

Liu, Zhiyuan; Meng, Qiang

2014-05-01

This paper focuses on modelling the network flow equilibrium problem on a multimodal transport network with bus-based park-and-ride (P&R) system and congestion pricing charges. The multimodal network has three travel modes: auto mode, transit mode and P&R mode. A continuously distributed value-of-time is assumed to convert toll charges and transit fares to time unit, and the users' route choice behaviour is assumed to follow the probit-based stochastic user equilibrium principle with elastic demand. These two assumptions have caused randomness to the users' generalised travel times on the multimodal network. A comprehensive network framework is first defined for the flow equilibrium problem with consideration of interactions between auto flows and transit (bus) flows. Then, a fixed-point model with unique solution is proposed for the equilibrium flows, which can be solved by a convergent cost averaging method. Finally, the proposed methodology is tested by a network example.

Modeling and Simulation of Bus Dispatching Policy for Timed Transfers on Signalized Networks

NASA Astrophysics Data System (ADS)

Cho, Hsun-Jung; Lin, Guey-Shii

2007-12-01

The major work of this study is to formulate the system cost functions and to integrate the bus dispatching policy with signal control. The integrated model mainly includes the flow dispersion model for links, signal control model for nodes, and dispatching control model for transfer terminals. All such models are inter-related for transfer operations in one-center transit network. The integrated model that combines dispatching policies with flexible signal control modes can be applied to assess the effectiveness of transfer operations. It is found that, if bus arrival information is reliable, an early dispatching decision made at the mean bus arrival times is preferable. The costs for coordinated operations with slack times are relatively low at the optimal common headway when applying adaptive route control. Based on such findings, a threshold function of bus headway for justifying an adaptive signal route control under various time values of auto drivers is developed.

Electrical Design and Evaluation of Asynchronous Serial Bus Communication Network of 48 Sensor Platform LSIs with Single-Ended I/O for Integrated MEMS-LSI Sensors

PubMed Central

Shao, Chenzhong; Tanaka, Shuji; Nakayama, Takahiro; Hata, Yoshiyuki

2018-01-01

For installing many sensors in a limited space with a limited computing resource, the digitization of the sensor output at the site of sensation has advantages such as a small amount of wiring, low signal interference and high scalability. For this purpose, we have developed a dedicated Complementary Metal-Oxide-Semiconductor (CMOS) Large-Scale Integration (LSI) (referred to as “sensor platform LSI”) for bus-networked Micro-Electro-Mechanical-Systems (MEMS)-LSI integrated sensors. In this LSI, collision avoidance, adaptation and event-driven functions are simply implemented to relieve data collision and congestion in asynchronous serial bus communication. In this study, we developed a network system with 48 sensor platform LSIs based on Printed Circuit Board (PCB) in a backbone bus topology with the bus length being 2.4 m. We evaluated the serial communication performance when 48 LSIs operated simultaneously with the adaptation function. The number of data packets received from each LSI was almost identical, and the average sampling frequency of 384 capacitance channels (eight for each LSI) was 73.66 Hz. PMID:29342923

WITS - A Coaxial Cable Bus Network for Medical Applications

PubMed Central

LaSonde, Clarence J.

1980-01-01

Walter Reed ARMY Medical Center has been serving as a Army test bed for coaxial cable-based local area networks since early 1978. This particular network, called the WRAMC Information Transfer System (WITS), carries commercial television, FM radio, closed-circuit TV and maintenance intercom audio, as well as digital data. The technology has proven successful. Broadband coaxial cable systems provide an opportunity to realize communications architectures that are flexible, highly reliable, and inexpensive. They are particularly appropriate for use in medical facilities where applications change over time and when many and varied systems are required to interact together.

Design Report for Isolated RS-485 Bus Node

DTIC Science & Technology

2016-07-01

controlled wired RS-485 network. The Android-based smartphone or tablet is used in conjunction with a USB to serial bridge to operate as the bus master in...Android-based smartphone or tablet is used in conjunction with a USB to serial bridge to operate as the bus master in the system. The Android device

A study on some urban bus transport networks

NASA Astrophysics Data System (ADS)

Chen, Yong-Zhou; Li, Nan; He, Da-Ren

2007-03-01

In this paper, we present the empirical investigation results on the urban bus transport networks (BTNs) of four major cities in China. In BTN, nodes are bus stops. Two nodes are connected by an edge when the stops are serviced by a common bus route. The empirical results show that the degree distributions of BTNs take exponential function forms. Other two statistical properties of BTNs are also considered, and they are suggested as the distributions of so-called “the number of stops in a bus route” (represented by S) and “the number of bus routes a stop joins” (by R). The distributions of R also show exponential function forms, while the distributions of S follow asymmetric, unimodal functions. To explain these empirical results and attempt to simulate a possible evolution process of BTN, we introduce a model by which the analytic and numerical result obtained agrees well with the empirical facts. Finally, we also discuss some other possible evolution cases, where the degree distribution shows a power law or an interpolation between the power law and the exponential decay.

Improved Results for Route Planning in Stochastic Transportation Networks

NASA Technical Reports Server (NTRS)

Boyan, Justin; Mitzenmacher, Michael

2000-01-01

In the bus network problem, the goal is to generate a plan for getting from point X to point Y within a city using buses in the smallest expected time. Because bus arrival times are not determined by a fixed schedule but instead may be random. the problem requires more than standard shortest path techniques. In recent work, Datar and Ranade provide algorithms in the case where bus arrivals are assumed to be independent and exponentially distributed. We offer solutions to two important generalizations of the problem, answering open questions posed by Datar and Ranade. First, we provide a polynomial time algorithm for a much wider class of arrival distributions, namely those with increasing failure rate. This class includes not only exponential distributions but also uniform, normal, and gamma distributions. Second, in the case where bus arrival times are independent and geometric discrete random variable,. we provide an algorithm for transportation networks of buses and trains, where trains run according to a fixed schedule.

A high-rate PCI-based telemetry processor system

NASA Astrophysics Data System (ADS)

Turri, R.

2002-07-01

The high performances reached by the Satellite on-board telemetry generation and transmission, as consequently, will impose the design of ground facilities with higher processing capabilities at low cost to allow a good diffusion of these ground station. The equipment normally used are based on complex, proprietary bus and computing architectures that prevent the systems from exploiting the continuous and rapid increasing in computing power available on market. The PCI bus systems now allow processing of high-rate data streams in a standard PC-system. At the same time the Windows NT operating system supports multitasking and symmetric multiprocessing, giving the capability to process high data rate signals. In addition, high-speed networking, 64 bit PCI-bus technologies and the increase in processor power and software, allow creating a system based on COTS products (which in future may be easily and inexpensively upgraded). In the frame of EUCLID RTP 9.8 project, a specific work element was dedicated to develop the architecture of a system able to acquire telemetry data of up to 600 Mbps. Laben S.p.A - a Finmeccanica Company -, entrusted of this work, has designed a PCI-based telemetry system making possible the communication between a satellite down-link and a wide area network at the required rate.

Efficient and Robust Data Collection Using Compact Micro Hardware, Distributed Bus Architectures and Optimizing Software

NASA Technical Reports Server (NTRS)

Chau, Savio; Vatan, Farrokh; Randolph, Vincent; Baroth, Edmund C.

2006-01-01

Future In-Space propulsion systems for exploration programs will invariably require data collection from a large number of sensors. Consider the sensors needed for monitoring several vehicle systems states of health, including the collection of structural health data, over a large area. This would include the fuel tanks, habitat structure, and science containment of systems required for Lunar, Mars, or deep space exploration. Such a system would consist of several hundred or even thousands of sensors. Conventional avionics system design will require these sensors to be connected to a few Remote Health Units (RHU), which are connected to robust, micro flight computers through a serial bus. This results in a large mass of cabling and unacceptable weight. This paper first gives a survey of several techniques that may reduce the cabling mass for sensors. These techniques can be categorized into four classes: power line communication, serial sensor buses, compound serial buses, and wireless network. The power line communication approach uses the power line to carry both power and data, so that the conventional data lines can be eliminated. The serial sensor bus approach reduces most of the cabling by connecting all the sensors with a single (or redundant) serial bus. Many standard buses for industrial control and sensor buses can support several hundreds of nodes, however, have not been space qualified. Conventional avionics serial buses such as the Mil-Std-1553B bus and IEEE 1394a are space qualified but can support only a limited number of nodes. The third approach is to combine avionics buses to increase their addressability. The reliability, EMI/EMC, and flight qualification issues of wireless networks have to be addressed. Several wireless networks such as the IEEE 802.11 and Ultra Wide Band are surveyed in this paper. The placement of sensors can also affect cable mass. Excessive sensors increase the number of cables unnecessarily. Insufficient number of sensors may not provide adequate coverage of the system. This paper also discusses an optimal technique to place and validate sensors.

Combined Quarterly Technical Report Number 25. SATNET Development and Operation, Pluribus Satellite IMP Development, Remote Site Maintenance, Internet Operations and Maintenance, Mobile Access Terminal Network, TCP for the HP3000, TCP for VAX-UNIX.

DTIC Science & Technology

1982-05-01

the F-Bus. The two possible SuperSUE I Pollers, SSPE and SSPF, are on the E and F buses, respectively. P13 is the P13 Poller. A PSAT will have at... SSPE and SSPF are again the two possible SuperSUE Pollers. HPOL is an abbrevation for the HINPOL and HOUTPOL routines. -44- jReport No. 5003 Bolt...I IS I E-Bus,F-Bus I E-Bus Only I F-Bus only I s -- - - - - - - - - - - - - - - - - -- - - - - - P E-Bus ISMIE/ SSPE ISMIE/ SSPE ISMIF/SSPF IF-Bu3

Multilevel-Dc-Bus Inverter For Providing Sinusoidal And Pwm Electrical Machine Voltages

DOEpatents

Su, Gui-Jia [Knoxville, TN

2005-11-29

A circuit for controlling an ac machine comprises a full bridge network of commutation switches which are connected to supply current for a corresponding voltage phase to the stator windings, a plurality of diodes, each in parallel connection to a respective one of the commutation switches, a plurality of dc source connections providing a multi-level dc bus for the full bridge network of commutation switches to produce sinusoidal voltages or PWM signals, and a controller connected for control of said dc source connections and said full bridge network of commutation switches to output substantially sinusoidal voltages to the stator windings. With the invention, the number of semiconductor switches is reduced to m+3 for a multi-level dc bus having m levels. A method of machine control is also disclosed.

RICA: a reliable and image configurable arena for cyborg bumblebee based on CAN bus.

PubMed

Gong, Fan; Zheng, Nenggan; Xue, Lei; Xu, Kedi; Zheng, Xiaoxiang

2014-01-01

In this paper, we designed a reliable and image configurable flight arena, RICA, for developing cyborg bumblebees. To meet the spatial and temporal requirements of bumblebees, the Controller Area Network (CAN) bus is adopted to interconnect the LED display modules to ensure the reliability and real-time performance of the arena system. Easily-configurable interfaces on a desktop computer implemented by python scripts are provided to transmit the visual patterns to the LED distributor online and configure RICA dynamically. The new arena system will be a power tool to investigate the quantitative relationship between the visual inputs and induced flight behaviors and also will be helpful to the visual-motor research in other related fields.

Network protocols for real-time applications

NASA Technical Reports Server (NTRS)

Johnson, Marjory J.

1987-01-01

The Fiber Distributed Data Interface (FDDI) and the SAE AE-9B High Speed Ring Bus (HSRB) are emerging standards for high-performance token ring local area networks. FDDI was designed to be a general-purpose high-performance network. HSRB was designed specifically for military real-time applications. A workshop was conducted at NASA Ames Research Center in January, 1987 to compare and contrast these protocols with respect to their ability to support real-time applications. This report summarizes workshop presentations and includes an independent comparison of the two protocols. A conclusion reached at the workshop was that current protocols for the upper layers of the Open Systems Interconnection (OSI) network model are inadequate for real-time applications.

A 250-Mbit/s ring local computer network using 1.3-microns single-mode optical fibers

NASA Technical Reports Server (NTRS)

Eng, S. T.; Tell, R.; Andersson, T.; Eng, B.

1985-01-01

A 250-Mbit/s three-station fiber-optic ring local computer network was built and successfully demonstrated. A conventional token protocol was employed for bus arbitration to maximize the bus efficiency under high loading conditions, and a non-return-to-zero (NRS) data encoding format was selected for simplicity and maximum utilization of the ECL-circuit bandwidth.

Impacts of Vehicle (In)Security

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chugg, J.; Rohde, K.

Nuclear and radioactive material is routinely transported worldwide every day. Since 2010, the complexity of the transport vehicle to support such activities has grown exponentially. Many core functions of a vehicle are now handled by small embedded computer modules with more being added each year to enhance the owner’s experience and convenience. With a system as complex as today’s automobile, the potential for cyber security issues is certain. Hackers have begun exploring this new domain with public information increasingly disseminated. Because vehicles are allowed into and around secure nuclear facilities, the potential for using a vehicle as a new cybermore » entry point or vector into the facility is now plausible and must be mitigated. In addition, compromising such a vehicle could aide in illicit removal of nuclear material, putting sensitive cargo at risk. Because cyber attacks can now be introduced using vehicles, cyber security, needs to be integrated into an organization’s design basis threat document. Essentially, a vehicle now extends the perimeter for which security professionals are responsible.Electronic Control Units (ECU) responsible for handling all core and ancillary vehicle functions are interconnected using the controller area network (CAN) bus. A typical CAN network in a modern automobile contains 50 or more ECUs. The CAN protocol now supports a wide variety of areas, including automotive, road transportation, rail transportation, industrial automation, power generation, maritime, military vehicles, aviation, and medical devices. In many ways, the nuclear industry is employing the CAN bus protocol or other similar broadcast serial networks. This paper will provide an overview of the current state of automobile and CAN Bus security, as well as an overview of what has been publicly disclosed by many research organizations. It will then present several hypotheses of how vehicle security issues may impact nuclear activities. An initial discussion of how a vehicle can be used as a new threat vector to penetrate secure facilities will be presented. This includes how a modern automobile can be used as the exploitation mechanism for nearby devices such as laptops, cell phones, and wireless access points. Additional discussion will highlight how vehicle security might impact transportation of nuclear material through remote exploitation of a moving vehicle. The final discussion will include what possible implications might be relative to the physical protection systems at nuclear facilities. The audience will also be given details regarding the complexity of attack, thus implying the likelihood of successful exploitation, and information on how such attacks may be mitigated. Emerging security products for automobiles will be discussed and other mitigation methods will be detailed (e.g. disabling vehicle cellular modems). As a result, the audience will have a greater understanding of how to add vehicle security as a part of a comprehensive nuclear security policy.Finally, this paper will highlight the similarities between CAN Bus and other broadcast serial bus networks such as Profibus or DeviceNet, helping educate the reader on how susceptible this type of networking is to nefarious attacks and how it might affect components connected to many different nuclear systems, including control systems, safety systems, emergency systems, and support systems.« less

Quantifying patron needs at intermodal facilities.

DOT National Transportation Integrated Search

2011-07-01

New Jersey has a varied network of commuter rail, light rail, bus, paratransit, county and private : shuttle services. These services meet a range of needs including commuter travel to major : employment centers, local bus service for various trip pu...

Simulation studies of multiple large wind turbine generators on a utility network

NASA Technical Reports Server (NTRS)

Gilbert, L. J.; Triezenberg, D. M.

1979-01-01

The potential electrical problems that may be inherent in the inertia of clusters of wind turbine generators and an electric utility network were investigated. Preliminary and limited results of an analog simulation of two MOD-2 wind generators tied to an infinite bus indicate little interaction between the generators and between the generators and the bus. The system demonstrated transient stability for the conditions considered.

An experimental study on real time bus arrival time prediction with GPS data

DOT National Transportation Integrated Search

2001-01-01

Bus headway in a rural area is usually much larger than that in an urban area. Providing real-time bus : arrival information could make the public transit system more user-friendly and thus enhance its : competitiveness among various transportation m...

An experimental study on real time bus arrival time prediction with GPS data

DOT National Transportation Integrated Search

1999-01-01

Bus headway in a rural area usually is much larger than that in an urban area. Providing real-time bus arrival information could make the public transit system more user-friendly and thus enhance its competitiveness among various transportation modes...

Real-Time-Simulation of IEEE-5-Bus Network on OPAL-RT-OP4510 Simulator

NASA Astrophysics Data System (ADS)

Atul Bhandakkar, Anjali; Mathew, Lini, Dr.

2018-03-01

The Real-Time Simulator tools have high computing technologies, improved performance. They are widely used for design and improvement of electrical systems. The advancement of the software tools like MATLAB/SIMULINK with its Real-Time Workshop (RTW) and Real-Time Windows Target (RTWT), real-time simulators are used extensively in many engineering fields, such as industry, education, and research institutions. OPAL-RT-OP4510 is a Real-Time Simulator which is used in both industry and academia. In this paper, the real-time simulation of IEEE-5-Bus network is carried out by means of OPAL-RT-OP4510 with CRO and other hardware. The performance of the network is observed with the introduction of fault at various locations. The waveforms of voltage, current, active and reactive power are observed in the MATLAB simulation environment and on the CRO. Also, Load Flow Analysis (LFA) of IEEE-5-Bus network is computed using MATLAB/Simulink power-gui load flow tool.

Empirical study on a directed and weighted bus transport network in China

NASA Astrophysics Data System (ADS)

Feng, Shumin; Hu, Baoyu; Nie, Cen; Shen, Xianghao

2016-01-01

Bus transport networks are directed complex networks that consist of routes, stations, and passenger flow. In this study, the concept of duplication factor is introduced to analyze the differences between uplinks and downlinks for the bus transport network of Harbin (BTN-H). Further, a new representation model for BTNs is proposed, named as directed-space P. Two empirical characteristics of BTN-H are reported in this paper. First, the cumulative distributions of weighted degree, degree, number of routes that connect to each station, and node weight (peak-hour trips at a station) uniformly follow the exponential law. Meanwhile, the node weight shows positive correlations with the corresponding weighted degree, degree, and number of routes that connect to a station. Second, a new richness parameter of a node is explored by its node weight and the connectivity, weighted connectivity, average shortest path length and efficiency between rich nodes can be fitted by composite exponential functions to demonstrate the rich-club phenomenon.

Mars Comm/Nav MicroSat Network Using the Multi-Mission Bus Launched Piggyback by Ariane 5

NASA Technical Reports Server (NTRS)

Hastrup, R. C.; Cesarone, R. J.; Morabito, D. D.

1999-01-01

Recently, NASA's Jet Propulsion Laboratory completed a Mars Exploration Program Architecture Definition Study with strong international participation. The recommendations of this study include establishment of a low cost in-situ communications and navigation satellite network to provide enabling and enhancing support for the international exploration of Mars. This would be the first step toward establishing a "virtual presence throughout the solar system" as called for in NASA's Strategic Plan. Response to the proposed comm/nav satellite network has been very favorably received, as reflected by the inclusion of a line item in NASA's budget submittal to Congress, which provides funding for implementation of the network with first launch in the 2003 opportunity. Funding has already been provided for a phase A study being conducted this year. This paper presents the planned implementation of the comm/nav network, which will utilize microsats based on a multi-mission spacecraft bus being designed for launch by the Ariane 5 as a secondary payload. A companion paper at this conference, entitled "The Multi-Purpose Mars Micro-Mission System Design Utilizing Ariane 5 Piggyback Launch", describes the multimission bus design. This paper addresses the application of the multi-mission bus to the comm/nav microsat mission. Following an introduction, which provides the background that has led to the proposed comm/nav network, the paper discusses the projected user needs with emphasis on the various possible robotic missions (landers, rovers, ascent vehicles, balloons, aircraft, etc.) progressing toward eventual piloted missions. Next, the paper describes the concept for an evolving network of comm/nav microsats and the expected capability to satisfy the user needs. Results of communications and navigation performance analysis are summarized for attractive satellite constellation configurations. The important comm/nav microsat functional requirements on the multi-mission spacecraft bus are described with discussion of the mission-system tradeoffs for the driving requirements. The functional design of the in-situ communications / navigation package, which constitutes the payload of the microsat, is also described. The paper also includes discussion of technologies which are of specific importance to the implementation of the comm/nav microsat network.

Network design analysis for special needs student services.

DOT National Transportation Integrated Search

2010-06-01

Population growth can lead to public school capacity issues, as well as increased school bus utilization. This increased utilization, in turn, can result in longer school bus transport times for both regular and special needs/medically fragile studen...

Crashworthiness evaluation of mass transit buses.

DOT National Transportation Integrated Search

2008-11-01

Mass transit bus systems are an integral part of the national transportation network, serving more than 20.6 billion passenger-miles per year with a relatively low fatality rate. Bus occupant injuries are evenly distributed among crashes on all sides...

Lewis Research Center studies of multiple large wind turbine generators on a utility network

NASA Technical Reports Server (NTRS)

Gilbert, L. J.; Triezenberg, D. M.

1979-01-01

A NASA-Lewis program to study the anticipated performance of a wind turbine generator farm on an electric utility network is surveyed. The paper describes the approach of the Lewis Wind Energy Project Office to developing analysis capabilities in the area of wind turbine generator-utility network computer simulations. Attention is given to areas such as, the Lewis Purdue hybrid simulation, an independent stability study, DOE multiunit plant study, and the WEST simulator. Also covered are the Lewis mod-2 simulation including analog simulation of a two wind turbine system and comparison with Boeing simulation results, and gust response of a two machine model. Finally future work to be done is noted and it is concluded that the study shows little interaction between the generators and between the generators and the bus.

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

Development of hybrid genetic-algorithm-based neural networks using regression trees for modeling air quality inside a public transportation bus.

PubMed

Kadiyala, Akhil; Kaur, Devinder; Kumar, Ashok

2013-02-01

The present study developed a novel approach to modeling indoor air quality (IAQ) of a public transportation bus by the development of hybrid genetic-algorithm-based neural networks (also known as evolutionary neural networks) with input variables optimized from using the regression trees, referred as the GART approach. This study validated the applicability of the GART modeling approach in solving complex nonlinear systems by accurately predicting the monitored contaminants of carbon dioxide (CO2), carbon monoxide (CO), nitric oxide (NO), sulfur dioxide (SO2), 0.3-0.4 microm sized particle numbers, 0.4-0.5 microm sized particle numbers, particulate matter (PM) concentrations less than 1.0 microm (PM10), and PM concentrations less than 2.5 microm (PM2.5) inside a public transportation bus operating on 20% grade biodiesel in Toledo, OH. First, the important variables affecting each monitored in-bus contaminant were determined using regression trees. Second, the analysis of variance was used as a complimentary sensitivity analysis to the regression tree results to determine a subset of statistically significant variables affecting each monitored in-bus contaminant. Finally, the identified subsets of statistically significant variables were used as inputs to develop three artificial neural network (ANN) models. The models developed were regression tree-based back-propagation network (BPN-RT), regression tree-based radial basis function network (RBFN-RT), and GART models. Performance measures were used to validate the predictive capacity of the developed IAQ models. The results from this approach were compared with the results obtained from using a theoretical approach and a generalized practicable approach to modeling IAQ that included the consideration of additional independent variables when developing the aforementioned ANN models. The hybrid GART models were able to capture majority of the variance in the monitored in-bus contaminants. The genetic-algorithm-based neural network IAQ models outperformed the traditional ANN methods of the back-propagation and the radial basis function networks. The novelty of this research is the development of a novel approach to modeling vehicular indoor air quality by integration of the advanced methods of genetic algorithms, regression trees, and the analysis of variance for the monitored in-vehicle gaseous and particulate matter contaminants, and comparing the results obtained from using the developed approach with conventional artificial intelligence techniques of back propagation networks and radial basis function networks. This study validated the newly developed approach using holdout and threefold cross-validation methods. These results are of great interest to scientists, researchers, and the public in understanding the various aspects of modeling an indoor microenvironment. This methodology can easily be extended to other fields of study also.

A study of headway maintenance for bus routes : causes and effects of "bus bunching" in extensive and congested service areas.

DOT National Transportation Integrated Search

2012-07-01

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

Cascading failures in interconnected networks with dynamical redistribution of loads

NASA Astrophysics Data System (ADS)

Zhao, Zhuang; Zhang, Peng; Yang, Hujiang

2015-09-01

Cascading failures of loads in isolated networks and coupled networks have been studied in the past few years. In most of the corresponding results, the topologies of the networks are destroyed. Here, we present an interconnected network model considering cascading failures based on the dynamic redistribution of flow in the networks. Compared with the results of single scale-free networks, we find that interconnected scale-free networks have higher vulnerability. Additionally, the network heterogeneity plays an important role in the robustness of interconnected networks under intentional attacks. Considering the effects of various coupling preferences, the results show that there are almost no differences. Finally, the application of our model to the Beijing interconnected traffic network, which consists of a subway network and a bus network, shows that the subway network suffers more damage under the attack. Moreover, the interconnected traffic network may be more exposed to damage after initial attacks on the bus network. These discussions are important for the design and optimization of interconnected networks.

Intrusion Detection System Using Deep Neural Network for In-Vehicle Network Security.

PubMed

Kang, Min-Joo; Kang, Je-Won

2016-01-01

A novel intrusion detection system (IDS) using a deep neural network (DNN) is proposed to enhance the security of in-vehicular network. The parameters building the DNN structure are trained with probability-based feature vectors that are extracted from the in-vehicular network packets. For a given packet, the DNN provides the probability of each class discriminating normal and attack packets, and, thus the sensor can identify any malicious attack to the vehicle. As compared to the traditional artificial neural network applied to the IDS, the proposed technique adopts recent advances in deep learning studies such as initializing the parameters through the unsupervised pre-training of deep belief networks (DBN), therefore improving the detection accuracy. It is demonstrated with experimental results that the proposed technique can provide a real-time response to the attack with a significantly improved detection ratio in controller area network (CAN) bus.

Intrusion Detection System Using Deep Neural Network for In-Vehicle Network Security

PubMed Central

Kang, Min-Joo

2016-01-01

A novel intrusion detection system (IDS) using a deep neural network (DNN) is proposed to enhance the security of in-vehicular network. The parameters building the DNN structure are trained with probability-based feature vectors that are extracted from the in-vehicular network packets. For a given packet, the DNN provides the probability of each class discriminating normal and attack packets, and, thus the sensor can identify any malicious attack to the vehicle. As compared to the traditional artificial neural network applied to the IDS, the proposed technique adopts recent advances in deep learning studies such as initializing the parameters through the unsupervised pre-training of deep belief networks (DBN), therefore improving the detection accuracy. It is demonstrated with experimental results that the proposed technique can provide a real-time response to the attack with a significantly improved detection ratio in controller area network (CAN) bus. PMID:27271802

Car travel time and accessibility by bus to general practitioner services: a study using patient registers and GIS.

PubMed

Lovett, Andrew; Haynes, Robin; Sünnenberg, Gisela; Gale, Susan

2002-07-01

Accessibility to general practitioner (GP) surgeries was investigated in a population study of East Anglia (Cambridgeshire, Norfolk and Suffolk) in the United Kingdom. Information from patient registers was combined with details of general practitioner surgery locations, road network characteristics, bus routes and community transport services, and a geographical information system (GIS) was used to calculate measures of accessibility to surgeries by public and private transport. Outcome measures included car travel times and indicators of the extent to which bus services could be used to visit GP surgeries. These variables were aggregated for wards or parishes and then compared with socio-economic characteristics of the populations living in those areas. The results indicated that only 10% of residents faced a car journey of more than 10 min to a GP. Some 13% of the population could not reach general medical services by daily bus. For 5% of the population, the car journey to the nearest surgery was longer than 10 min and there was no suitable bus service each weekday. In the remoter rural parishes, the lowest levels of personal mobility and the highest health needs indicators were found in the places with no daytime bus service each weekday and no community transport. The overall extent of accessibility problems and the existence of inverse care law effects in some rural localities have implications for the NHS, which aims to provide an equitable service to people wherever they live. The research also demonstrates the potential of patient registers and GIS as research and planning tools, though the practical difficulties of using these data sources and techniques should not be underestimated.

Effect of bus-stop spacing on mobile emissions in urban areas.

DOT National Transportation Integrated Search

2003-01-01

The operational effect of bus-stop spacing has been a critical issue. Closely spaced bus stops : disrupt the traffic flow on the bus route, particularly during peak hours because buses make frequent stops : to provide services to customers. The disru...

Stability improvement of wind turbine penetrated using power system stabilizer (PSS) on South Sulawesi transmission system

NASA Astrophysics Data System (ADS)

Siswanto, Agus; Gunadin, Indar Chaerah; Said, Sri Mawar; Suyuti, Ansar

2018-03-01

The purpose of this research is to improve the stability of interconnection of South Sulawesi system caused by penetration new wind turbine in Sidrap area on bus 2 and in Jeniponto area on bus 34. The method used in this research was via software Power System analysis Toolbox (PSAT) under MATLAB. In this research, there are two problems that are evaluated, the stability of the system before and after penetration wind turbine into the system South Sulawesi system. From the simulation result shows that penetration of wind turbine on bus 2 Sidrap, bus 37 Jeniponto give effect oscillation on the system. The oscillation was damped by installation of Power System Stabilizer (PSS) on bus 29 area Sungguminasa, that South Sulawesi system stable according to normal condition.

High Speed All-Optical Data Distribution Network

NASA Astrophysics Data System (ADS)

Braun, Steve; Hodara, Henri

2017-11-01

This article describes the performance and capabilities of an all-optical network featuring low latency, high speed file transfer between serially connected optical nodes. A basic component of the network is a network interface card (NIC) implemented through a unique planar lightwave circuit (PLC) that performs add/drop data and optical signal amplification. The network uses a linear bus topology with nodes in a "T" configuration, as described in the text. The signal is sent optically (hence, no latency) to all nodes via wavelength division multiplexing (WDM), with each node receiver tuned to wavelength of choice via an optical de-multiplexer. Each "T" node routes a portion of the signal to/from the bus through optical couplers, embedded in the network interface card (NIC), to each of the 1 through n computers.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor)

2005-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted by the network device interface into digital signals and transmitted back to the controller. In one advantageous embodiment, the network device interface uses a specialized protocol for communicating across the network bus that uses a low-level instruction set and has low overhead for data communication.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Ellerbrock, Philip J. (Inventor); Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor); Grant, Robert L. (Inventor)

2004-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted by the network device interface into digital signals and transmitted back to the controller. In one advantageous embodiment, the network device interface uses a specialized protocol for communicating across the network bus that uses a low-level instruction set and has low overhead for data communication.

Preliminary concept for statewide intercity bus and rail transit system : priority corridor ranking and analysis.

DOT National Transportation Integrated Search

2009-03-01

This product summarizes the preliminary concept and priority corridors for development of a potential : statewide intercity bus and rail network. The concept is based upon the results of Tasks 1 through 5 of Texas : Department of Transportation Proje...

Bus driving assistance system for town area by using ATmega328P microcontroller

NASA Astrophysics Data System (ADS)

Zakaria, Mohamad Fauzi; Soon, Tan Jiah; Rohani, Munzilah Md

2017-09-01

Recently, several bus accidents happened because of bus driver's behavior. In fact, there is no dedicated tool for assisting them to drive safely. This project gives solutions to this by assisting the driver, according to the speed and acceleration of the bus. These data are collected by using a motion processing unit (MPU-6050) and a global positioning system (GPS) and then indicate the driving mode status on the LEDs. All data and status are recorded in a secure digital (SD) card for the authority or the bus company to analyze the driving behavior of a bus driver. This system has been successfully developed and tested in two different areas which includes the UTHM main campus and the road from Parit Raja to Batu Pahat.

Statistical analysis of passenger-crowding in bus transport network of Harbin

NASA Astrophysics Data System (ADS)

Hu, Baoyu; Feng, Shumin; Li, Jinyang; Zhao, Hu

2018-01-01

Passenger flow data is indispensable but rare in the study of public transport networks. In this study, we focus on the passenger-crowding characteristics of the bus transport network of Harbin (BTN-H) based on passenger flow investigation. The three frequency histograms for all the uplinks and downlinks in Harbin are presented, including passengers on the bus at each section, crowding coefficients, and position parameters of crowded sections. The differences in crowding position are analyzed on each route. The distributions of degree and crowding degree (in directed space L) follow an exponential law. The new finding indicates that there are many stations with few crowded sections and a few stations with many crowded sections. The distributions of path length and crowded length (in directed space P) are presented based on the minimum transfer times, and it is found that they can be fitted by a composite Gaussian function and a Gaussian function, respectively. The stations and paths can be divided into three crowd levels. We conclude that BTN-H is crowded from a network-based perspective.

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Ellerbrock, Philip J. (Inventor); Winkelmann, Joseph P. (Inventor); Grant, Robert L. (Inventor); Konz, Daniel W. (Inventor)

2006-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is then converted by the network device interface into digital signals and transmitted back to the controller. In one advantageous embodiment, the network device interface is a state machine, such as an ASIC, that operates independent of a processor in communicating with the bus controller and data channels.

Multi-Scale Visualization Analysis of Bus Flow Average Travel Speed in Qingdao

NASA Astrophysics Data System (ADS)

Yong, HAN; Man, GAO; Xiao-Lei, ZHANG; Jie, LI; Ge, CHEN

2016-11-01

Public transportation is a kind of complex spatiotemporal behaviour. The traffic congestion and environmental pollution caused by the increase in private cars is becoming more and more serious in our city. Spatiotemporal data visualization is an effective tool for studying traffic, transforming non-visual data into recognizable images, which can reveal where/when congestion is formed, developed and disappeared in space and time simultaneously. This paper develops a multi-scale visualization of average travel speed derived from floating bus data, to enable congestion on urban bus networks to be shown and analyzed. The techniques of R language, Echarts, WebGL are used to draw statistical pictures and 3D wall map, which show the congestion in Qingdao from the view of space and time. The results are as follows:(1) There is a more severely delay in Shibei and Shinan areas than Licun and Laoshan areas; (2) The high congestion usually occurs on Hong Kong Middle Road, Shandong Road, Nanjing Road, Liaoyang West Road and Taiping Road;(3) There is a similar law from Monday to Sunday that the congestion is severer in the morning and evening rush hours than other hours; (4) On Monday morning the severity of congestion is higher than on Friday morning, and on Friday evening the severity is higher than on Monday evening. The research results will help to improve the public transportation of Qingdao.

Bus accident analysis of routes with/without bus priority.

PubMed

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

2014-04-01

This paper summarises findings on road safety performance and bus-involved accidents in Melbourne along roads where bus priority measures had been applied. Results from an empirical analysis of the accident types revealed significant reduction in the proportion of accidents involving buses hitting stationary objects and vehicles, which suggests the effect of bus priority in addressing manoeuvrability issues for buses. A mixed-effects negative binomial (MENB) regression and back-propagation neural network (BPNN) modelling of bus accidents considering wider influences on accident rates at a route section level also revealed significant safety benefits when bus priority is provided. Sensitivity analyses done on the BPNN model showed general agreement in the predicted accident frequency between both models. The slightly better performance recorded by the MENB model results suggests merits in adopting a mixed effects modelling approach for accident count prediction in practice given its capability to account for unobserved location and time-specific factors. A major implication of this research is that bus priority in Melbourne's context acts to improve road safety and should be a major consideration for road management agencies when implementing bus priority and road schemes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Implementation of a Cooking Bus intervention to support cooking in schools in Wales, UK

PubMed Central

Segrott, Jeremy; Holliday, Jo; Murphy, Simon; Macdonald, Sarah; Roberts, Joan; Moore, Laurence; Phillips, Ceri

2017-01-01

Purpose The teaching of cooking is an important aspect of school-based efforts to promote healthy diets among children, and is frequently done by external agencies. Within a limited evidence base relating to cooking interventions in schools, there are important questions about how interventions are integrated within school settings. The purpose of this paper is to examine how a mobile classroom (Cooking Bus) sought to strengthen connections between schools and cooking, and drawing on the concept of the sociotechnical network, theorise the interactions between the Bus and school contexts. Design/methodology/approach Methods comprised a postal questionnaire to 76 schools which had received a Bus visit, and case studies of the Bus’ work in five schools, including a range of school sizes and urban/rural locations. Case studies comprised observation of Cooking Bus sessions, and interviews with school staff. Findings The Cooking Bus forged connections with schools through aligning intervention and schools’ goals, focussing on pupils’ cooking skills, training teachers and contributing to schools’ existing cooking-related activities. The Bus expanded its sociotechnical network through post-visit integration of cooking activities within schools, particularly teachers’ use of intervention cooking kits. Research limitations/implications The paper highlights the need for research on the long-term impacts of school cooking interventions, and better understanding of the interaction between interventions and school contexts. Originality/value This paper adds to the limited evidence base on school-based cooking interventions by theorising how cooking interventions relate to school settings, and how they may achieve integration. PMID:28725120

Modeling inter-signal arrival times for accurate detection of CAN bus signal injection attacks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, Michael Roy; Bridges, Robert A; Combs, Frank L

Modern vehicles rely on hundreds of on-board electronic control units (ECUs) communicating over in-vehicle networks. As external interfaces to the car control networks (such as the on-board diagnostic (OBD) port, auxiliary media ports, etc.) become common, and vehicle-to-vehicle / vehicle-to-infrastructure technology is in the near future, the attack surface for vehicles grows, exposing control networks to potentially life-critical attacks. This paper addresses the need for securing the CAN bus by detecting anomalous traffic patterns via unusual refresh rates of certain commands. While previous works have identified signal frequency as an important feature for CAN bus intrusion detection, this paper providesmore » the first such algorithm with experiments on five attack scenarios. Our data-driven anomaly detection algorithm requires only five seconds of training time (on normal data) and achieves true positive / false discovery rates of 0.9998/0.00298, respectively (micro-averaged across the five experimental tests).« less

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Konz, Daniel W. (Inventor); Winkelmann, Joseph P. (Inventor); Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor)

2007-01-01

The present invention provides a network device interface and method for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is converted into digital signals and transmitted to the controller. In some embodiments, network device interfaces associated with different data channels coordinate communications with the other interfaces based on either a transition in a command message sent by the bus controller or a synchronous clock signal.

Emission inventory estimation of an intercity bus terminal.

PubMed

Qiu, Zhaowen; Li, Xiaoxia; Hao, Yanzhao; Deng, Shunxi; Gao, H Oliver

2016-06-01

Intercity bus terminals are hotspots of air pollution due to concentrated activities of diesel buses. In order to evaluate the bus terminals' impact on air quality, it is necessary to estimate the associated mobile emission inventories. Since the vehicles' operating condition at the bus terminal varies significantly, conventional calculation of the emissions based on average emission factors suffers the loss of accuracy. In this study, we examined a typical intercity bus terminal-the Southern City Bus Station of Xi'an, China-using a multi-scale emission model-(US EPA's MOVES model)-to quantity the vehicle emission inventory. A representative operating cycle for buses within the station is constructed. The emission inventory was then estimated using detailed inputs including vehicle ages, operating speeds, operating schedules, and operating mode distribution, as well as meteorological data (temperature and humidity). Five functional areas (bus yard, platforms, disembarking area, bus travel routes within the station, and bus entrance/exit routes) at the terminal were identified, and the bus operation cycle was established using the micro-trip cycle construction method. Results of our case study showed that switching to compressed natural gas (CNG) from diesel fuel could reduce PM2.5 and CO emissions by 85.64 and 6.21 %, respectively, in the microenvironment of the bus terminal. When CNG is used, tail pipe exhaust PM2.5 emission is significantly reduced, even less than brake wear PM2.5. The estimated bus operating cycles can also offer researchers and policy makers important information for emission evaluation in the planning and design of any typical intercity bus terminals of a similar scale.

Development and Implementation of a Bus Driver Training Program.

ERIC Educational Resources Information Center

Buchovecky, John G.

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

Empirical investigation of topological and weighted properties of a bus transport network from China

NASA Astrophysics Data System (ADS)

Shu-Min, Feng; Bao-Yu, Hu; Cen, Nie; Xiang-Hao, Shen; Yu-Sheng, Ci

2016-03-01

Many bus transport networks (BTNs) have evolved into directed networks. A new representation model for BTNs is proposed, called directed-space P. The bus transport network of Harbin (BTN-H) is described as a directed and weighted complex network by the proposed representation model and by giving each node weights. The topological and weighted properties are revealed in detail. In-degree and out-degree distributions, in-weight and out-weight distributions are presented as an exponential law, respectively. There is a strong relation between in-weight and in-degree (also between out-weight and out-degree), which can be fitted by a power function. Degree-degree and weight-weight correlations are investigated to reveal that BTN-H has a disassortative behavior as the nodes have relatively high degree (or weight). The disparity distributions of out-degree and in-degree follow an approximate power-law. Besides, the node degree shows a near linear increase with the number of routes that connect to the corresponding station. These properties revealed in this paper can help public transport planners to analyze the status quo of the BTN in nature. Project supported by the National High Technology Research and Development Program of China (Grant No. 2014AA110304).

Network device interface for digitally interfacing data channels to a controller via a network

NASA Technical Reports Server (NTRS)

Ellerbrock, Philip J. (Inventor); Grant, Robert L. (Inventor); Winkelmann, Joseph P. (Inventor); Konz, Daniel W. (Inventor)

2009-01-01

A communications system and method are provided for digitally connecting a plurality of data channels, such as sensors, actuators, and subsystems, to a controller using a network bus. The network device interface interprets commands and data received from the controller and polls the data channels in accordance with these commands. Specifically, the network device interface receives digital commands and data from the controller, and based on these commands and data, communicates with the data channels to either retrieve data in the case of a sensor or send data to activate an actuator. Data retrieved from the sensor is converted into digital signals and transmitted to the controller. Network device interfaces associated with different data channels can coordinate communications with the other interfaces based on either a transition in a command message sent by the bus controller or a synchronous clock signal.

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

PubMed

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

2012-05-01

Much recent public health research has emphasised the health impacts for young people of 'active travel' modes, typically defined as walking and cycling. Less research has focused on public transport modes. Drawing on qualitative data, we examine the links between bus travel and wellbeing in London, where young people currently have free bus travel. Our findings indicate that bus travel can be both a physically and socially active experience for young people. We suggest a more nuanced understanding of 'active travel' is now needed, alongside greater attention to urban public transport networks as key sites that impact on important determinants of wellbeing such as independent mobility and social inclusion. Copyright © 2012 Elsevier Ltd. All rights reserved.

Mission Services Evolution Center Message Bus

NASA Technical Reports Server (NTRS)

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

2011-01-01

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

A Survey of Some Approaches to Distributed Data Base & Distributed File System Architecture.

DTIC Science & Technology

1980-01-01

BUS POD A DD A 12 12 A = A Cell D = D Cell Figure 7-1: MUFFIN logical architecture - 45 - MUFI January 1980 ".-.Bus Interface V Conventional Processor...and Applied Mathematics (14), * December, 1966. [Kimbleton 791 Kimbleton, Stephen; Wang, Pearl; and Fong, Elizabeth. XNDM: An Experimental Network

The fiber-optic high-speed data bus for a new generation of military aircraft

NASA Astrophysics Data System (ADS)

Uhlhorn, Roger W.

1991-02-01

The avionic suite for the next generation of military aircraft is being designed with component and module commonality in mind in order to control recurring costs and capitalize on economy of scale. The backbone of the suite fashioned out of these modular building blocks is the fiber-optic bit-serial time-division multiplexed high-speed data bus (HSDB), operating at 50 Mb/s, which provides command and control communications among most of the aircraft subsystems and can be used to provide communications for a fly-by-light flight-control system or for the block transfer of data between mass memories and data processors. The fiber-optic HSDB is examined from the top down, beginning with an overview of the evolution of avionic architectures. A review is given of the standardization activity associated with development of the network, the protocols chosen to implement the desired communication functions, configuration options, and the fiber-optic components used in the bus interfaces or other active nodes of the network. It is believed that the utility of the bus extends beyond aircraft to spacecraft, ships, and land vehicles.

Effect of distributed generation installation on power loss using genetic algorithm method

NASA Astrophysics Data System (ADS)

Hasibuan, A.; Masri, S.; Othman, W. A. F. W. B.

2018-02-01

Injection of the generator distributed in the distribution network can affect the power system significantly. The effect that occurs depends on the allocation of DG on each part of the distribution network. Implementation of this approach has been made to the IEEE 30 bus standard and shows the optimum location and size of the DG which shows a decrease in power losses in the system. This paper aims to show the impact of distributed generation on the distribution system losses. The main purpose of installing DG on a distribution system is to reduce power losses on the power system.Some problems in power systems that can be solved with the installation of DG, one of which will be explored in the use of DG in this study is to reduce the power loss in the transmission line. Simulation results from case studies on the IEEE 30 bus standard system show that the system power loss decreased from 5.7781 MW to 1,5757 MW or just 27,27%. The simulated DG is injected to the bus with the lowest voltage drop on the bus number 8.

Chattanooga SmartBus Project : phase III evaluation report

DOT National Transportation Integrated Search

2009-12-01

This report presents the results of Phase III of the national evaluation of the Chattanooga Area Regional Transportation Authoritys (CARTA) SmartBus Project. The SmartBus Project is a comprehensive transit ITS program for the city of Chattanooga, ...

Efficiency and robustness of different bus network designs

NASA Astrophysics Data System (ADS)

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

2015-07-01

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

Methodology of mixed load customized bus lines and adjustment based on time windows

PubMed Central

Song, Rui

2018-01-01

Custom bus routes need to be optimized to meet the needs of a customized bus for personalized trips of different passengers. This paper introduced a customized bus routing problem in which trips for each depot are given, and each bus stop has a fixed time window within which trips should be completed. Treating a trip as a virtual stop was the first consideration in solving the school bus routing problem (SBRP). Then, the mixed load custom bus routing model was established with a time window that satisfies its requirement and the result were solved by Cplex software. Finally, a simple network diagram with three depots, four pickup stops, and five delivery stops was structured to verify the correctness of the model, and based on the actual example, the result is that all the buses ran 124.42 kilometers, the sum of kilometers was 10.35 kilometers less than before. The paths and departure times of the different busses that were provided by the model were evaluated to meet the needs of the given conditions, thus providing valuable information for actual work. PMID:29320505

Multi-modal two-step floating catchment area analysis of primary health care accessibility.

PubMed

Langford, Mitchel; Higgs, Gary; Fry, Richard

2016-03-01

Two-step floating catchment area (2SFCA) techniques are popular for measuring potential geographical accessibility to health care services. This paper proposes methodological enhancements to increase the sophistication of the 2SFCA methodology by incorporating both public and private transport modes using dedicated network datasets. The proposed model yields separate accessibility scores for each modal group at each demand point to better reflect the differential accessibility levels experienced by each cohort. An empirical study of primary health care facilities in South Wales, UK, is used to illustrate the approach. Outcomes suggest the bus-riding cohort of each census tract experience much lower accessibility levels than those estimated by an undifferentiated (car-only) model. Car drivers' accessibility may also be misrepresented in an undifferentiated model because they potentially profit from the lower demand placed upon service provision points by bus riders. The ability to specify independent catchment sizes for each cohort in the multi-modal model allows aspects of preparedness to travel to be investigated. Copyright © 2016. Published by Elsevier Ltd.

Connecting and Networking for Schools

EPA Pesticide Factsheets

Resources for connecting and networking for schools through e-newsletters, finding school IAQ Champions and other EPA school programs such as Asthma, Energy Star, Clean School Bus USA, School Flag, etc.

Spacelab, Spacehab, and Space Station Freedom payload interface projects

NASA Technical Reports Server (NTRS)

Smith, Dean Lance

1992-01-01

Contributions were made to several projects. Howard Nguyen was assisted in developing the Space Station RPS (Rack Power Supply). The RPS is a computer controlled power supply that helps test equipment used for experiments before the equipment is installed on Space Station Freedom. Ron Bennett of General Electric Government Services was assisted in the design and analysis of the Standard Interface Rack Controller hardware and software. An analysis was made of the GPIB (General Purpose Interface Bus), looking for any potential problems while transmitting data across the bus, such as the interaction of the bus controller with a data talker and its listeners. An analysis was made of GPIB bus communications in general, including any negative impact the bus may have on transmitting data back to Earth. A study was made of transmitting digital data back to Earth over a video channel. A report was written about the study and a revised version of the report will be submitted for publication. Work was started on the design of a PC/AT compatible circuit board that will combine digital data with a video signal. Another PC/AT compatible circuit board is being designed to recover the digital data from the video signal. A proposal was submitted to support the continued development of the interface boards after the author returns to Memphis State University in the fall. A study was also made of storing circuit board design software and data on the hard disk server of a LAN (Local Area Network) that connects several IBM style PCs. A report was written that makes several recommendations. A preliminary design review was started of the AIVS (Automatic Interface Verification System). The summer was over before any significant contribution could be made to this project.

Analysis of Mesh Distribution Systems Considering Load Models and Load Growth Impact with Loops on System Performance

NASA Astrophysics Data System (ADS)

Kumar Sharma, A.; Murty, V. V. S. N.

2014-12-01

The distribution system is the final link between bulk power system and consumer end. A distinctive load flow solution method is used for analysis of the load flow of radial and weakly meshed network based on Kirchhoff's Current Law (KCL) and KVL. This method has excellent convergence characteristics for both radial as well as weakly meshed structure and is based on bus injection to branch current and branch-current to bus-voltage matrix. The main contribution of the paper is: (i) an analysis has been carried out for a weekly mesh network considering number of loops addition and its impact on the losses, kW and kVAr requirements from a system, and voltage profile, (ii) different load models, realistic ZIP load model and load growth impact on losses, voltage profile, kVA and kVAr requirements, (iii) impact of addition of loops on losses, voltage profile, kVA and kVAr requirements from substation, and (iv) comparison of system performance with radial distribution system. Voltage stability is a major concern in planning and operation of power systems. This paper also includes identifying the closeness critical bus which is the most sensitive to the voltage collapse in radial distribution networks. Node having minimum value of voltage stability index is the most sensitive node. Voltage stability index values are computed for meshed network with number of loops added in the system. The results have been obtained for IEEE 33 and 69 bus test system. The results have also been obtained for radial distribution system for comparison.

American Fuel Cell Bus Project Evaluation : Third Report

DOT National Transportation Integrated Search

2017-05-01

This report presents results of the American Fuel Cell Bus (AFCB) Project, a demonstration of fuel cell electric buses (FCEB) operating in the Coachella Valley area of California. The AFCB, built on an ElDorado National-California 40-foot Axess bus p...

Emergence of criticality in the transportation passenger flow: scaling and renormalization in the Seoul bus system.

PubMed

Goh, Segun; Lee, Keumsook; Choi, Moo Young; Fortin, Jean-Yves

2014-01-01

Social systems have recently attracted much attention, with attempts to understand social behavior with the aid of statistical mechanics applied to complex systems. Collective properties of such systems emerge from couplings between components, for example, individual persons, transportation nodes such as airports or subway stations, and administrative districts. Among various collective properties, criticality is known as a characteristic property of a complex system, which helps the systems to respond flexibly to external perturbations. This work considers the criticality of the urban transportation system entailed in the massive smart card data on the Seoul transportation network. Analyzing the passenger flow on the Seoul bus system during one week, we find explicit power-law correlations in the system, that is, power-law behavior of the strength correlation function of bus stops and verify scale invariance of the strength fluctuations. Such criticality is probed by means of the scaling and renormalization analysis of the modified gravity model applied to the system. Here a group of nearby (bare) bus stops are transformed into a (renormalized) "block stop" and the scaling relations of the network density turn out to be closely related to the fractal dimensions of the system, revealing the underlying structure. Specifically, the resulting renormalized values of the gravity exponent and of the Hill coefficient give a good description of the Seoul bus system: The former measures the characteristic dimensionality of the network whereas the latter reflects the coupling between distinct transportation modes. It is thus demonstrated that such ideas of physics as scaling and renormalization can be applied successfully to social phenomena exemplified by the passenger flow.

Emergence of Criticality in the Transportation Passenger Flow: Scaling and Renormalization in the Seoul Bus System

PubMed Central

Goh, Segun; Lee, Keumsook; Choi, MooYoung; Fortin, Jean-Yves

2014-01-01

Social systems have recently attracted much attention, with attempts to understand social behavior with the aid of statistical mechanics applied to complex systems. Collective properties of such systems emerge from couplings between components, for example, individual persons, transportation nodes such as airports or subway stations, and administrative districts. Among various collective properties, criticality is known as a characteristic property of a complex system, which helps the systems to respond flexibly to external perturbations. This work considers the criticality of the urban transportation system entailed in the massive smart card data on the Seoul transportation network. Analyzing the passenger flow on the Seoul bus system during one week, we find explicit power-law correlations in the system, that is, power-law behavior of the strength correlation function of bus stops and verify scale invariance of the strength fluctuations. Such criticality is probed by means of the scaling and renormalization analysis of the modified gravity model applied to the system. Here a group of nearby (bare) bus stops are transformed into a (renormalized) “block stop” and the scaling relations of the network density turn out to be closely related to the fractal dimensions of the system, revealing the underlying structure. Specifically, the resulting renormalized values of the gravity exponent and of the Hill coefficient give a good description of the Seoul bus system: The former measures the characteristic dimensionality of the network whereas the latter reflects the coupling between distinct transportation modes. It is thus demonstrated that such ideas of physics as scaling and renormalization can be applied successfully to social phenomena exemplified by the passenger flow. PMID:24599221

Distributed control system for parallel-connected DC boost converters

DOEpatents

Goldsmith, Steven

2017-08-15

The disclosed invention is a distributed control system for operating a DC bus fed by disparate DC power sources that service a known or unknown load. The voltage sources vary in v-i characteristics and have time-varying, maximum supply capacities. Each source is connected to the bus via a boost converter, which may have different dynamic characteristics and power transfer capacities, but are controlled through PWM. The invention tracks the time-varying power sources and apportions their power contribution while maintaining the DC bus voltage within the specifications. A central digital controller solves the steady-state system for the optimal duty cycle settings that achieve a desired power supply apportionment scheme for a known or predictable DC load. A distributed networked control system is derived from the central system that utilizes communications among controllers to compute a shared estimate of the unknown time-varying load through shared bus current measurements and bus voltage measurements.

Short-term exposure to PM 10, PM 2.5, ultrafine particles and CO 2 for passengers at an intercity bus terminal

NASA Astrophysics Data System (ADS)

Cheng, Yu-Hsiang; Chang, Hsiao-Peng; Hsieh, Cheng-Ju

2011-04-01

The Taipei Bus Station is the main transportation hub for over 50 bus routes to eastern, central, and southern Taiwan. Daily traffic volume at this station is about 2500 vehicles, serving over 45,000 passengers daily. The station is a massive 24-story building housing a bus terminal, a business hotel, a shopping mall, several cinemas, offices, private residential suites, and over 900 parking spaces. However, air quality inside this bus terminal is a concern as over 2500 buses are scheduled to run daily. This study investigates the PM 10, PM 2.5, UFP and CO 2 levels inside and outside the bus terminal. All measurements were taken between February and April 2010. Measurement results show that coarse PM inside the bus terminal was resuspended by the movement of large numbers of passengers. The fine and ultrafine PM in the station concourse were from outside vehicles. Moreover, fine and ultrafine PM at waiting areas were exhausted directly from buses in the building. The CO 2 levels at waiting areas were likely elevated by bus exhaust and passengers exhaling. The PM 10, PM 2.5 and CO 2 levels at the bus terminal were lower than Taiwan's EPA suggested standards for indoor air quality. However, UFP levels at the bus terminal were significantly higher than those in the urban background by about 10 times. Therefore, the effects of UFPs on the health of passengers and workers must be addressed at this bus terminal since the levels of UFPs are higher than >1.0 × 10 5 particles cm -3.

Concept and Design of the Hybrid Sensor Bus System for Telecommunication Satellites

NASA Astrophysics Data System (ADS)

Hurni, Andreas; Tiefenbeck, Christoph; Manhart, Markus; Heyer, Heinz-Volker; Plattner, Markus; Putzer, Philipp; Roßner, Max; Koch, Alexander W.; Furano, Gianluca; McKenzie, Iain; Lam, King

2012-08-01

The Hybrid Sensor Bus (HSB) is a system for sensor interrogation in telecommunication satellites, which will be developed in the frame of the ESA ARTES program. The main target of the HSB system is the replacement of classical point-to-point wired sensors by sensors connected on bus networks. This will save mass and reduces efforts in assembly, integration and testing (AIT). The HSB system is able to manage an electrical I2C and a fiber-optical sensor network. The system consists of an intelligent power module, an electrical and a fiber-optical interrogator module in cold redundancy. Additional features of the HSB system are its modularity and the adaptability to different satellite platforms. The implementation of a HSB system allows platform manufacturers to build a more cost efficient satellite.This paper presents the concept and the design status of the HSB system.

PMU Data Integrity Evaluation through Analytics on a Virtual Test-Bed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olama, Mohammed M.; Shankar, Mallikarjun

Power systems are rapidly becoming populated by phasor measurement units (PMUs) in ever increasing numbers. PMUs are critical components of today s energy management systems, designed to enable near real-time wide area monitoring and control of the electric power system. They are able to measure highly accurate bus voltage phasors as well as branch current phasors incident to the buses at which PMUs are equipped. Synchrophasor data is used for applications varying from state estimation, islanding control, identifying outages, voltage stability detection and correction, disturbance recording, and others. However, PMU-measured readings may suffer from errors due to meter biases ormore » drifts, incorrect configurations, or even cyber-attacks. Furthermore, the testing of early PMUs showed a large disparity between the reported values from PMUs provided by different manufacturers, particularly when frequency was off-nominal, during dynamic events, and when harmonic/inter-harmonic content was present. Detection and identification of PMU gross measurement errors are thus crucial in maintaining highly accurate phasor readings throughout the system. In this paper, we present our work in conducting analytics to determine the trustworthiness and worth of the PMU readings collected across an electric network system. By implementing the IEEE 118 bus test case on a virtual test bed (VTB) , we are able to emulate PMU readings (bus voltage and branch current phasors in addition to bus frequencies) under normal and abnormal conditions using (virtual) PMU sensors deployed across major substations in the network. We emulate a variety of failures such as bus, line, transformer, generator, and/or load failures. Data analytics on the voltage phase angles and frequencies collected from the PMUs show that specious (or compromised) PMU device(s) can be identified through abnormal behaviour by comparing the trend of its frequency and phase angle reading with the ensemble of all other PMU readings in the network. If the reading trend of a particular PMU deviates from the weighted average of the reading trends of other PMUs at nearby substations, then it is likely that the PMU is malfunctioning. We assign a weight to each PMU denoting how electric-topology-wise close it is from where the PMU under consideration is located. The closer a PMU is, the higher the weight it has. To compute the closeness between two nodes in the power network, we employ a form of the resistance distance metric. It computes the electrical distance by taking into consideration the underlying topology as well as the physical laws that govern the electrical connections or flows between the network components. The detection accuracy of erroneous PMUs should be improved by employing this metric. We present results to validate the proposed approach. We also discuss the effectiveness of using an end-to-end VTB approach that allows us to investigate different types of failures and their responses as seen by the ensemble of PMUs. The collected data on certain types of events may be amenable to certain types of analysis (e.g., alerting for sudden changes can be done on a small window of data) and hence determine the data analytics architectures is required to evaluate the streaming PMU data.« less

Development of bus-stop time models in dense urban areas : a case study in Washington DC.

DOT National Transportation Integrated Search

2015-08-01

Bus transit reliability depends on several factors including the route of travel, traffic conditions, time of day, and conditions at : the bus stops along the route. The number of passengers alighting or boarding, fare payment method, dwell time (DT)...

BBIS: Beacon Bus Information System

NASA Astrophysics Data System (ADS)

Kasim, Shahreen; Hafit, Hanayanti; Pei Juin, Kong; Afizah Afif, Zehan; Hashim, Rathiah; Ruslai, Husni; Jahidin, Kamaruzzaman; Syafwan Arshad, Mohammad

2016-11-01

Lack of bus information for example bus timetable, status of the bus and messy advertisement on bulletin board at the bus stop will give negative impact to tourist. Therefore, a real-time update bus information bulletin board provides all information needed so that passengers can save their bus information searching time. Supported with Android or iOS, Beacon Bus Information System (BBIS) provides bus information between Batu Pahat and Kluang area. BBIS is a system that implements physical web technology and interaction on demand. It built on Backend-as-a-Service, a cloud solution and Firebase non relational database as data persistence backend and syncs between user client in the real-time. People walk through bus stop with smart device and do not require any application. Bluetooth Beacon is used to achieve smart device's best performance of data sharing. Intellij IDEA 15 is one of the tools that that used to develop the BBIS system. Multi-language included front end and backend supported Integration development environment (IDE) helped to speed up integration process.

Deadly Lessons.

ERIC Educational Resources Information Center

Vail, Kathleen

1996-01-01

In Fox River Grove, Illinois, 7 teenagers were killed the morning of October 25, 1995, when a 620-ton commuter train crashed into the rear end of their school bus. School, transportation, and safety officials have focused on three areas: train crossings and signals, bus-driver training, and school-bus construction. Lists 10 vital lessons for…

A Study of the Effects of Fieldbus Network Induced Delays on Control Systems

ERIC Educational Resources Information Center

Mainoo, Joseph

2012-01-01

Fieldbus networks are all-digital, two-way, multi-drop communication systems that are used to connect field devices such as sensors and actuators, and controllers. These fieldbus network systems are also called networked control systems (NCS). Although, there are different varieties of fieldbus networks such as Foundation Field Bus, DeviceNet, and…

Comparative study of fuel cell, battery and hybrid buses for renewable energy constrained areas

NASA Astrophysics Data System (ADS)

Stempien, J. P.; Chan, S. H.

2017-02-01

Fuel cell- and battery-based public bus technologies are reviewed and compared for application in tropical urban areas. This paper scrutinizes the reported literature on fuel cell bus, fuel cell electric bus, battery electric bus, hybrid electric bus, internal combustion diesel bus and compressed natural gas bus. The comparison includes the capital and operating costs, fuel consumption and fuel cycle emissions. To the best of authors knowledge, this is the first study to holistically compare hydrogen and battery powered buses, which is the original contribution of this paper. Moreover, this is the first study to focus on supplying hydrogen and electricity from fossil resources, while including the associated emissions. The study shows that compressed natural gas and hybrid electric buses appear to be the cheapest options in terms of total cost of ownership, but they are unable to meet the EURO VI emissions' standard requirement. Only fuel cell based buses have the potential to achieve the emissions' standard when the fuel cycle based on fossil energy was considered. Fuel cell electric buses are identified as a technology allowing for the largest CO2 emission reduction, making ∼61% decrease in annual emissions possible.

Building the vision, a series of AZTech ITS model deployment success stories for the Phoenix metropolitan area : number ten : high-tech transit, using state-of-the art technology to keep bus riders informed

DOT National Transportation Integrated Search

1998-01-01

Traditionally, the biggest problem experienced by transit riders is a lack of information. They may not have access to a bus schedule. Or, even if they do have a copy of the Bus Book, they have no way of : knowing if their particular bus is on schedu...

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

NASA Technical Reports Server (NTRS)

Ruhman, Smil; Rosemberg, Flavia

1986-01-01

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.

Throughput analysis of the IEEE 802.4 token bus standard under heavy load

NASA Technical Reports Server (NTRS)

Pang, Joseph; Tobagi, Fouad

1987-01-01

It has become clear in the last few years that there is a trend towards integrated digital services. Parallel to the development of public Integrated Services Digital Network (ISDN) is service integration in the local area (e.g., a campus, a building, an aircraft). The types of services to be integrated depend very much on the specific local environment. However, applications tend to generate data traffic belonging to one of two classes. According to IEEE 802.4 terminology, the first major class of traffic is termed synchronous, such as packetized voice and data generated from other applications with real-time constraints, and the second class is called asynchronous which includes most computer data traffic such as file transfer or facsimile. The IEEE 802.4 token bus protocol which was designed to support both synchronous and asynchronous traffic is examined. The protocol is basically a timer-controlled token bus access scheme. By a suitable choice of the design parameters, it can be shown that access delay is bounded for synchronous traffic. As well, the bandwidth allocated to asynchronous traffic can be controlled. A throughput analysis of the protocol under heavy load with constant channel occupation of synchronous traffic and constant token-passing times is presented.

Magnitude and correlates of bird collisions at glass bus shelters in an urban landscape.

PubMed

Barton, Christine M; Riding, Corey S; Loss, Scott R

2017-01-01

Wildlife residing in urban landscapes face many human-related threats to their survival. For birds, collision with glass on manmade structures has been identified as a major hazard, causing hundreds of millions of avian fatalities in North America every year. Although research has investigated factors associated with bird-glass collision mortality at buildings, no prior studies have focused on bird fatalities at glass-walled bus shelters. Our objectives in this study were to describe the magnitude of bird-bus shelter collisions in the city of Stillwater, Oklahoma and assess potential predictors of collision risk, including characteristics of shelters (glass area) and surrounding land cover (e.g., vegetative features). We surveyed for bird carcasses and indirect collision evidence at 18 bus shelters over a five-month period. Linear regression and model selection results revealed that the amount of glass on shelters and the area of lawn within 50 m of shelters were both positively related to fatal bird collisions; glass area was also positively associated with observations of collision evidence on glass surfaces. After accounting for scavenger removal of carcasses, we estimate that a minimum of 34 birds are killed each year between May and September by collision with the 36 bus shelters in the city of Stillwater. While our study provides an initial look at bird fatalities at bus shelters, additional research is needed to generate a large-scale estimate of collision mortality and to assess species composition of fatalities at a national scale. Designing new bus shelters to include less glass and retrofitting existing shelters to increase visibility of glass to birds will likely reduce fatal bird collisions at bus shelters and thus reduce the cumulative magnitude of anthropogenic impacts to birds in cities.

State intercity bus plan : a report to the California Legislature in conformity with Chapter 99, item 266-001-041 of the 1981 Budget Act

DOT National Transportation Integrated Search

1982-03-01

The legislative directive for the State Intercity Bus Plan asked that the Department offer alternatives for future State involvement in the intercity bus area, estimates for the projected State capital and operating costs and revenues for each of the...

Extensibility and limitations of FDDI

NASA Technical Reports Server (NTRS)

Game, David; Maly, Kurt J.

1990-01-01

Recently two standards for Metropolitan Area Networks (MANs), Fiber Distributed Data Interface (FDDI) and Distributed Queue Dual Bus (DQDB), have emerged as the primary competitors for the MAN arena. Great interest exists in building higher speed networks which support large numbers of node and greater distance, and it is not clear what types of protocols are needed for this type of environment. There is some question as to whether or not these MAN standards can be extended to such environments. The extensibility of FDDI to the Gbps range and a long distance environment is investigated. Specification parameters which affect performance are shown and a measure is provided for predicting utilization of FDDI. A comparison of FDDI at 100 Mbps and 1 Gbps is presented. Some specific problems with FDDI are addressed and modifications which improve the viability of FDDI in such high speed networks are investigated.

Harmonic Resonance in Power Transmission Systems due to the Addition of Shunt Capacitors

NASA Astrophysics Data System (ADS)

Patil, Hardik U.

Shunt capacitors are often added in transmission networks at suitable locations to improve the voltage profile. In this thesis, the transmission system in Arizona is considered as a test bed. Many shunt capacitors already exist in the Arizona transmission system and more are planned to be added. Addition of these shunt capacitors may create resonance conditions in response to harmonic voltages and currents. Such resonance, if it occurs, may create problematic issues in the system. It is main objective of this thesis to identify potential problematic effects that could occur after placing new shunt capacitors at selected buses in the Arizona network. Part of the objective is to create a systematic plan for avoidance of resonance issues. For this study, a method of capacitance scan is proposed. The bus admittance matrix is used as a model of the networked transmission system. The calculations on the admittance matrix were done using Matlab. The test bed is the actual transmission system in Arizona; however, for proprietary reasons, bus names are masked in the thesis copy intended for the public domain. The admittance matrix was obtained from data using the PowerWorld Simulator after equivalencing the 2016 summer peak load (planning case). The full Western Electricity Coordinating Council (WECC) system data were used. The equivalencing procedure retains only the Arizona portion of the WECC. The capacitor scan results for single capacitor placement and multiple capacitor placement cases are presented. Problematic cases are identified in the form of 'forbidden response. The harmonic voltage impact of known sources of harmonics, mainly large scale HVDC sources, is also presented. Specific key results for the study indicated include: (1) The forbidden zones obtained as per the IEEE 519 standard indicates the bus 10 to be the most problematic bus. (2) The forbidden zones also indicate that switching values for the switched shunt capacitor (if used) at bus 3 should be should be considered carefully to avoid resonance condition from existing. (3) The highest sensitivity of 0.0033 per unit for HVDC sources of harmonics was observed at bus 7 when all the HVDC sources were active at the same time.

Evaluation of bus emissions generated near bus stops

NASA Astrophysics Data System (ADS)

Yu, Qian; Li, Tiezhu

2014-03-01

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

Definition, analysis and development of an optical data distribution network for integrated avionics and control systems

NASA Technical Reports Server (NTRS)

Burns, R. R.

1981-01-01

The potential and functional requirements of fiber optic bus designs for next generation aircraft are assessed. State-of-the-art component evaluations and projections were used in the system study. Complex networks were decomposed into dedicated structures, star buses, and serial buses for detailed analysis. Comparisons of dedicated links, star buses, and serial buses with and without full duplex operation and with considerations for terminal to terminal communication requirements were obtained. This baseline was then used to consider potential extensions of busing methods to include wavelength multiplexing and optical switches. Example buses were illustrated for various areas of the aircraft as potential starting points for more detail analysis as the platform becomes definitized.

Analysis of a dc bus system with a nonlinear constant power load and its delayed feedback control.

PubMed

Konishi, Keiji; Sugitani, Yoshiki; Hara, Naoyuki

2014-02-01

This paper tackles a destabilizing problem of a direct-current (dc) bus system with constant power loads, which can be considered a fundamental problem of dc power grid networks. The present paper clarifies scenarios of the destabilization and applies the well-known delayed-feedback control to the stabilization of the destabilized bus system on the basis of nonlinear science. Further, we propose a systematic procedure for designing the delayed feedback controller. This controller can converge the bus voltage exactly on an unstable operating point without accurate information and can track it using tiny control energy even when a system parameter, such as the power consumption of the load, is slowly varied. These features demonstrate that delayed feedback control can be considered a strong candidate for solving the destabilizing problem.

Fuel Cell Electric Bus Evaluations | Hydrogen and Fuel Cells | NREL

Science.gov Websites

. Transit Fleets: Current Status 2017, L. Eudy and M. Post (November 2017) Zero Emission Bay Area (ZEBA ) Fuel Cell Bus Demonstration Results: Sixth Report, L. Eudy, M. Post, and M. Jeffers (September 2017 2017) American Fuel Cell Bus Project Evaluation: Third Report, L. Eudy, M. Post, and M. Jeffers (May

Comparison of Communication Architectures and Network Topologies for Distributed Propulsion Controls (Preprint)

DTIC Science & Technology

2013-05-01

logic to perform control function computations and are connected to the full authority digital engine control ( FADEC ) via a high-speed data...Digital Engine Control ( FADEC ) via a high speed data communication bus. The short term distributed engine control configu- rations will be core...concen- trator; and high temperature electronics, high speed communication bus between the data concentrator and the control law processor master FADEC

JPRS Report, Soviet Union, Political Affairs

DTIC Science & Technology

1988-11-28

in the development of its physical plant , improve designing , increase work quality, as well as strengthen order and organization in the sector...time, the Academy considers it essential to develop within its system a network of design bureaus and experimental plants . It must be said that almost...insufficiently developed physical plant . Over the last 10 years, not a single bus system has been built. For more than 6 years now, a trolley bus

Network Management of the SPLICE Computer Network.

DTIC Science & Technology

1982-12-01

Approved for public release; distri4ition unlimited. Network lanagenent Df the SPLICE Computer Network by Zriig E. Opal captaini United St~tes larine... structure of the network must leni itself t3 change and reconfiguration, one author [Ref. 2: p.21] recommended that a global bus topology be adopted for...statistics, trace statistics, snapshot statistiZs, artifi - cial traffic generators, auulat on, a network measurement center which includes control, collction

Tradeoffs between costs and greenhouse gas emissions in the design of urban transit systems

NASA Astrophysics Data System (ADS)

Griswold, Julia B.; Madanat, Samer; Horvath, Arpad

2013-12-01

Recent investments in the transit sector to address greenhouse gas emissions have concentrated on purchasing efficient replacement vehicles and inducing mode shift from the private automobile. There has been little focus on the potential of network and operational improvements, such as changes in headways, route spacing, and stop spacing, to reduce transit emissions. Most models of transit system design consider user and agency cost while ignoring emissions and the potential environmental benefit of operational improvements. We use a model to evaluate the user and agency costs as well as greenhouse gas benefit of design and operational improvements to transit systems. We examine how the operational characteristics of urban transit systems affect both costs and greenhouse gas emissions. The research identifies the Pareto frontier for designing an idealized transit network. Modes considered include bus, bus rapid transit (BRT), light rail transit (LRT), and metro (heavy) rail, with cost and emissions parameters appropriate for the United States. Passenger demand follows a many-to-many travel pattern with uniformly distributed origins and destinations. The approaches described could be used to optimize the network design of existing bus service or help to select a mode and design attributes for a new transit system. The results show that BRT provides the lowest cost but not the lowest emissions for our large city scenarios. Bus and LRT systems have low costs and the lowest emissions for our small city scenarios. Relatively large reductions in emissions from the cost-optimal system can be achieved with only minor increases in user travel time.

Grid Transmission Expansion Planning Model Based on Grid Vulnerability

NASA Astrophysics Data System (ADS)

Tang, Quan; Wang, Xi; Li, Ting; Zhang, Quanming; Zhang, Hongli; Li, Huaqiang

2018-03-01

Based on grid vulnerability and uniformity theory, proposed global network structure and state vulnerability factor model used to measure different grid models. established a multi-objective power grid planning model which considering the global power network vulnerability, economy and grid security constraint. Using improved chaos crossover and mutation genetic algorithm to optimize the optimal plan. For the problem of multi-objective optimization, dimension is not uniform, the weight is not easy given. Using principal component analysis (PCA) method to comprehensive assessment of the population every generation, make the results more objective and credible assessment. the feasibility and effectiveness of the proposed model are validated by simulation results of Garver-6 bus system and Garver-18 bus.

Some Protocols For Optical-Fiber Digital Communications

NASA Technical Reports Server (NTRS)

Yeh, Cavour; Gerla, Mario

1989-01-01

One works best in heavy traffic, another, in light traffic. Three protocols proposed for digital communications among stations connected by passive taps to pair of uni-directional optical-fiber buses. Mediate round-robin, bounded-delay access to buses by all stations and particularly suited to fast transmission. Partly because transmission medium passive (no relay stations) and partly because protocols distribute control of network among all stations with provision for addition and deletion of stations (no control stations), communication network able to resist and recover from failures. Implicit token propagates in one direction on one bus and in opposite direction on other bus, minimizing interval of silence between end of one round and beginning of next.

User-based representation of time-resolved multimodal public transportation networks.

PubMed

Alessandretti, Laura; Karsai, Márton; Gauvin, Laetitia

2016-07-01

Multimodal transportation systems, with several coexisting services like bus, tram and metro, can be represented as time-resolved multilayer networks where the different transportation modes connecting the same set of nodes are associated with distinct network layers. Their quantitative description became possible recently due to openly accessible datasets describing the geo-localized transportation dynamics of large urban areas. Advancements call for novel analytics, which combines earlier established methods and exploits the inherent complexity of the data. Here, we provide a novel user-based representation of public transportation systems, which combines representations, accounting for the presence of multiple lines and reducing the effect of spatial embeddedness, while considering the total travel time, its variability across the schedule, and taking into account the number of transfers necessary. After the adjustment of earlier techniques to the novel representation framework, we analyse the public transportation systems of several French municipal areas and identify hidden patterns of privileged connections. Furthermore, we study their efficiency as compared to the commuting flow. The proposed representation could help to enhance resilience of local transportation systems to provide better design policies for future developments.

User-based representation of time-resolved multimodal public transportation networks

PubMed Central

Alessandretti, Laura; Gauvin, Laetitia

2016-01-01

Multimodal transportation systems, with several coexisting services like bus, tram and metro, can be represented as time-resolved multilayer networks where the different transportation modes connecting the same set of nodes are associated with distinct network layers. Their quantitative description became possible recently due to openly accessible datasets describing the geo-localized transportation dynamics of large urban areas. Advancements call for novel analytics, which combines earlier established methods and exploits the inherent complexity of the data. Here, we provide a novel user-based representation of public transportation systems, which combines representations, accounting for the presence of multiple lines and reducing the effect of spatial embeddedness, while considering the total travel time, its variability across the schedule, and taking into account the number of transfers necessary. After the adjustment of earlier techniques to the novel representation framework, we analyse the public transportation systems of several French municipal areas and identify hidden patterns of privileged connections. Furthermore, we study their efficiency as compared to the commuting flow. The proposed representation could help to enhance resilience of local transportation systems to provide better design policies for future developments. PMID:27493773

Can in Space-Status and Future after ECSS-E-ST-50-15C Release

NASA Astrophysics Data System (ADS)

Taylor, Chris; Furano, Gianluca; Valverde-Carretero, Alberto; Marinis, Kostas; Magistrati, Giorgio; Bolognino, Luca; Richard Jansen, King Lam; Caramia, Maurizio; Grau Llovera, Angel; Dalenq, Jean; Vinet, Francois

2015-09-01

Nowadays Controller Area Network (CAN) Bus is used more and more in spacecraft onboard applications. It has already been successfully used in many missions (ATV, SMART-1, MATROSHKA, SSTL Satellites, SENTINEL-2 etc.), will soon be the the main onboard communications bus for the EXOMars Mission and in will enable extended capabilities on future European Telecom palatforms. CAN Bus provides numerous advantages (robust, low cost, low power consumption, European, etc.). Thanks to its wide acceptance in the commercial market, numerous development tools are available that support and reduce the cost of all the engineering process, from specifications and design to the final assembly, integration and tests. Since 2009, ESA-ESTEC established an ESA-Industry Working Group on CAN Bus, in order to identify the main issues for its use in space applications and drive research and development. This long process has finally provided as output an ECSS standard and a set of building blocks that fully enable deployment of CAN bus for platform and payload use in all classes of space missions. The EXOMars project team has spearheaded these efforts, taking as reference the draft guidelines, and has taken into account the particularities of the EXOMars mission requirements, in order to provide a consistent methodology for the development of the multiple units that need to interface with the CAN Bus. The selection of CANOpen as preferred higher layer protocol for CAN in space application is due to the experience and hindsight developed during this long and sometimes not linear process. Two notable efforts were the development of an hardware support layer (the CCIPC IP core) for the CANOpen protocol and the qualification of three rad hard transceivers compliant with CAN commercial ISO physical standard. The CCIPC development has been performed concurrently with the ECSS-E-50-15C standardization activities. This approach has allowed the constant monitoring of the adopted IP core design solution by the ECSS Working Group. The first flight of the CCIPC is foreseen in 2016 with the EXOMARS Entry Descent and Landing Demonstrator Module. This paper will focus on the implementation of CAN Bus for all the future sapce DHSs, both on the technical aspects of physical layer selection, particularities of the higher layer protocol, etc. and on the methodology aspects related to the procurement of multiple heterogeneous units that are required to provide a standard interface to the Bus. Finally, a critical review of the current CAN Bus draft ECSS standard will be presented, based on advantages and difficulties encountered in the application of the current draft standard in the ongoing space applications.

Bus--carpool FWY lanes in San Francisco area

DOE Office of Scientific and Technical Information (OSTI.GOV)

Newman, L.

1976-11-01

The California Department of Transportation is studying ways to increase the use of the urban freeway systems that will accommodate the maximum number of people with the least delay and the maximum possible safety in a cost-effective way. This paper describes operational features of four different projects under way, namely: a contraflow bus lane; a part-time bus lane in the same direction and unseparated from normal traffic; a bus-carpool lane also in the same direction and unseparated from normal traffic; and a preferential access to a metered freeway. (MCW)

Development of network-based multichannel neuromuscular electrical stimulation system for stroke rehabilitation.

PubMed

Qu, Hongen; Xie, Yongji; Liu, Xiaoxuan; He, Xin; Hao, Manzhao; Bao, Yong; Xie, Qing; Lan, Ning

2016-01-01

Neuromuscular electrical stimulation (NMES) is a promising assistive technology for stroke rehabilitation. Here we present the design and development of a multimuscle stimulation system as an emerging therapy for people with paretic stroke. A network-based multichannel NMES system was integrated based on dual bus architecture of communication and an H-bridge current regulator with a power booster. The structure of the system was a body area network embedded with multiple stimulators and a communication protocol of controlled area network to transmit muscle stimulation parameter information to individual stimulators. A graphical user interface was designed to allow clinicians to specify temporal patterns and muscle stimulation parameters. We completed and tested a prototype of the hardware and communication software modules of the multichannel NMES system. The prototype system was first verified in nondisabled subjects for safety, and then tested in subjects with stroke for feasibility with assisting multijoint movements. Results showed that synergistic stimulation of multiple muscles in subjects with stroke improved performance of multijoint movements with more natural velocity profiles at elbow and shoulder and reduced acromion excursion due to compensatory trunk rotation. The network-based NMES system may provide an innovative solution that allows more physiological activation of multiple muscles in multijoint task training for patients with stroke.

Network operating system

NASA Technical Reports Server (NTRS)

1985-01-01

Long-term and short-term objectives for the development of a network operating system for the Space Station are stated. The short-term objective is to develop a prototype network operating system for a 100 megabit/second fiber optic data bus. The long-term objective is to establish guidelines for writing a detailed specification for a Space Station network operating system. Major milestones are noted. Information is given in outline form.

A simple, effective media access protocol system for integrated, high data rate networks

NASA Technical Reports Server (NTRS)

Foudriat, E. C.; Maly, K.; Overstreet, C. M.; Khanna, S.; Zhang, L.

1992-01-01

The operation and performance of a dual media access protocol for integrated, gigabit networks are described. Unlike other dual protocols, each protocol supports a different class of traffic. The Carrier Sensed Multiple Access-Ring Network (CSMA/RN) protocol and the Circulating Reservation Packet (CRP) protocol support asynchronous and synchronous traffic, respectively. The two protocols operate with minimal impact upon each other. Performance information demonstrates that they support a complete range of integrated traffic loads, do not require call setup/termination or a special node for synchronous traffic control, and provide effective pre-use and recovery. The CRP also provides guaranteed access and fairness control for the asynchronous system. The paper demonstrates that the CSMA-CRP system fulfills many of the requirements for gigabit LAN-MAN networks most effectively and simply. To accomplish this, CSMA-CRP features are compared against similar ring and bus systems, such as Cambridge Fast Ring, Metaring, Cyclic Reservation Multiple Access, and Distributed Dual Queue Data Bus (DQDB).

Providing the full DDF link protection for bus-connected SIEPON based system architecture

NASA Astrophysics Data System (ADS)

Hwang, I.-Shyan; Pakpahan, Andrew Fernando; Liem, Andrew Tanny; Nikoukar, AliAkbar

2016-09-01

Currently a massive amount of traffic per second is delivered through EPON systems, one of the prominent access network technologies for delivering the next generation network. Therefore, it is vital to keep the EPON optical distribution network (ODN) working by providing the necessity protection mechanism in the deployed devices; otherwise, when failures occur it will cause a great loss for both network operators and business customers. In this paper, we propose a bus-connected architecture to protect and recover distribution drop fiber (DDF) link faults or transceiver failures at ONU(s) in SIEPON system. The proposed architecture provides a cost-effective architecture, which delivers the high fault-tolerance in handling multiple DDF faults, while also providing flexibility in choosing the backup ONU assignments. Simulation results show that the proposed architecture provides the reliability and maintains quality of service (QoS) performance in terms of mean packet delay, system throughput, packet loss and EF jitter when DDF link failures occur.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eudy, L.; Chandler, K.

2013-01-01

SunLine Transit Agency, which provides public transit services to the Coachella Valley area of California, has demonstrated hydrogen and fuel cell bus technologies for more than 10 years. In May 2010, SunLine began demonstrating the advanced technology (AT) fuel cell bus with a hybrid electric propulsion system, fuel cell power system, and lithium-based hybrid batteries. This report describes operations at SunLine for the AT fuel cell bus and five compressed natural gas buses. The U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is working with SunLine to evaluate the bus in real-world service to document the results and helpmore » 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.« less

Computer Simulation of an Electric Trolley Bus

DOT National Transportation Integrated Search

1979-12-01

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

Bicycle-bus conflict area study.

DOT National Transportation Integrated Search

2009-11-01

Increasing bicycle use and bus ridership are both desirable policy goals : from a sustainability standpoint, but on city streets these two modes of : transport are often in conflict. While occupying opposite ends of the size : and weight spectrum, th...

Chattanooga SmartBus Project : phase 2 evaluation report

DOT National Transportation Integrated Search

2008-06-10

This report presents the results of Phase II of the national evaluation of the Chattanooga Area Regional Transportation Authoritys (CARTAs) SmartBus Project. The Smartbus Project is a comprehensive transit ITS program for the city of Chattanoog...

Mass, surface area and number metrics in diesel occupational exposure assessment.

PubMed

Ramachandran, Gurumurthy; Paulsen, Dwane; Watts, Winthrop; Kittelson, David

2005-07-01

While diesel aerosol exposure assessment has traditionally been based on the mass concentration metric, recent studies have suggested that particle number and surface area concentrations may be more health-relevant. In this study, we evaluated the exposures of three occupational groups-bus drivers, parking garage attendants, and bus mechanics-using the mass concentration of elemental carbon (EC) as well as surface area and number concentrations. These occupational groups are exposed to mixtures of diesel and gasoline exhaust on a regular basis in various ratios. The three groups had significantly different exposures to workshift TWA EC with the highest levels observed in the bus garage mechanics and the lowest levels in the parking ramp booth attendants. In terms of surface area, parking ramp attendants had significantly greater exposures than bus garage mechanics, who in turn had significantly greater exposures than bus drivers. In terms of number concentrations, the exposures of garage mechanics exceeded those of ramp booth attendants by a factor of 5-6. Depending on the exposure metric chosen, the three occupational groups had quite different exposure rankings. This illustrates the importance of the choice of exposure metric in epidemiological studies. If these three occupational groups were part of an epidemiological study, depending on the metric used, they may or may not be part of the same similarly exposed group (SEG). The exposure rankings (e.g., low, medium, or high) of the three groups also changes with the metric used. If the incorrect metric is used, significant misclassification errors may occur.

On-line determination of transient stability status using multilayer perceptron neural network

NASA Astrophysics Data System (ADS)

Frimpong, Emmanuel Asuming; Okyere, Philip Yaw; Asumadu, Johnson

2018-01-01

A scheme to predict transient stability status following a disturbance is presented. The scheme is activated upon the tripping of a line or bus and operates as follows: Two samples of frequency deviation values at all generator buses are obtained. At each generator bus, the maximum frequency deviation within the two samples is extracted. A vector is then constructed from the extracted maximum frequency deviations. The Euclidean norm of the constructed vector is calculated and then fed as input to a trained multilayer perceptron neural network which predicts the stability status of the system. The scheme was tested using data generated from the New England test system. The scheme successfully predicted the stability status of all two hundred and five disturbance test cases.

Distributed Ship Navigation Control System Based on Dual Network

NASA Astrophysics Data System (ADS)

Yao, Ying; Lv, Wu

2017-10-01

Navigation system is very important for ship’s normal running. There are a lot of devices and sensors in the navigation system to guarantee ship’s regular work. In the past, these devices and sensors were usually connected via CAN bus for high performance and reliability. However, as the development of related devices and sensors, the navigation system also needs the ability of high information throughput and remote data sharing. To meet these new requirements, we propose the communication method based on dual network which contains CAN bus and industrial Ethernet. Also, we import multiple distributed control terminals with cooperative strategy based on the idea of synchronizing the status by multicasting UDP message contained operation timestamp to make the system more efficient and reliable.

The volume and type of unhealthy bus shelter advertising around schools in Perth, Western Australia: Results from an explorative study.

PubMed

Parnell, Ashleigh; Edmunds, Melinda; Pierce, Hannah; Stoneham, Melissa J

2018-03-05

Exposure to advertising for unhealthy food, alcohol and gambling has been shown to influence children and adolescents' behaviours and attitudes. This exploratory study aimed to assess the volume and type of unhealthy bus shelter advertisements near schools in five local government areas in Perth, Western Australia and to monitor whether the volume of unhealthy advertisements varied seasonally. The 29 local governments in the Perth metropolitan region were contacted seeking information regarding the locations of bus shelters featuring advertisements in their local government area. Five local governments provided sufficient information for an audit of the bus shelter advertisements in their area to be conducted. Every bus shelter within 500 m of a school was photographed and the type of advertisement recorded. The advertisements in the food, non-alcoholic beverage, alcohol, or gambling categories were then classified as being healthy, moderate, or unhealthy. This process was carried out in June, September, December 2016, and March 2017 to ascertain whether the type of advertisements displayed changed depending on the season. Of the 293 advertisements recorded over the four audits, 31% featured unhealthy products, 3% moderate, and <1% healthy. Only two of the 293 advertisements were classified as being healthy. Seasonal variation in the volume of unhealthy advertisements was not identified. SO WHAT?: Western Australian school students are regularly exposed to unhealthy bus shelter advertisements. Stricter regulation of outdoor advertising is needed to ensure that young people are protected from the influence of unhealthy industries. © 2018 Australian Health Promotion Association.

A smartphone-based platform to test the performance of wireless mobile networks and preliminary findings

NASA Astrophysics Data System (ADS)

Geng, Xinli; Xu, Hao; Qin, Xiaowei

2016-10-01

During the last several years, the amount of wireless network traffic data increased fast and relative technologies evolved rapidly. In order to improve the performance and Quality of Experience (QoE) of wireless network services, the analysis of field network data and existing delivery mechanisms comes to be a promising research topic. In order to achieve this goal, a smartphone based platform named Monitor and Diagnosis of Mobile Applications (MDMA) was developed to collect field data. Based on this tool, the web browsing service of High Speed Downlink Packet Access (HSDPA) network was tested. The top 200 popular websites in China were selected and loaded on smartphone for thousands times automatically. Communication packets between the smartphone and the cell station were captured for various scenarios (e.g. residential area, urban roads, bus station etc.) in the selected city. A cross-layer database was constructed to support the off-line analysis. Based on the results of client-side experiments and analysis, the usability of proposed portable tool was verified. The preliminary findings and results for existing web browsing service were also presented.

Telecommunication Platforms for Transmitting Sensor Data over Communication Networks-State of the Art and Challenges.

PubMed

Staniec, Kamil; Habrych, Marcin

2016-07-19

The importance of constructing wide-area sensor networks for holistic environmental state evaluation has been demonstrated. A general structure of such a network has been presented with distinction of three segments: local (based on ZigBee, Ethernet and ModBus techniques), core (base on cellular technologies) and the storage/application. The implementation of these techniques requires knowledge of their technical limitations and electromagnetic compatibility issues. The former refer to ZigBee performance degradation in multi-hop transmission, whereas the latter are associated with the common electromagnetic spectrum sharing with other existing technologies or with undesired radiated emissions generated by the radio modules of the sensor network. In many cases, it is also necessary to provide a measurement station with autonomous energy source, such as solar. As stems from measurements of the energetic efficiency of these sources, one should apply them with care and perform detailed power budget since their real performance may turn out to be far from expected. This, in turn, may negatively affect-in particular-the operation of chemical sensors implemented in the network as they often require additional heating.

Montana intercity bus service study.

DOT National Transportation Integrated Search

2011-12-01

Intercity bus service funding from the Federal Transit Administration (FTAs) Section 5311(f) program is a part : of the larger 5311 program known as Formula Grants for Other than Urbanized Areas. The S.5311(f), requires : that 15% of the total 531...

Network Management System for Tactical Mobile Ad Hoc Network Segments

DTIC Science & Technology

2011-09-01

Protocol UFO UHF Follow-On UHF Ultra High Frequency USB Universal Serial Bus VHF Very High Frequency VIRT Valuable Information at the Right Time...military satellite system known as the UHF Follow-on system ( UFO ) only provides capacity for 600 concurrent users. DoD users also have commercial

Urinary 1-hydroxypyrene and mutagenicity in bus drivers and mail carriers exposed to urban air pollution in Denmark.

PubMed

Hansen, Ase Marie; Wallin, Håkan; Binderup, Mona Lise; Dybdahl, Marianne; Autrup, Herman; Loft, Steffen; Knudsen, Lisbeth Ehlert

2004-01-10

Previous studies in Denmark have shown that bus drivers and tramway employees were at an increased risk for developing several types of cancer and that bus drives from central Copenhagen have high levels of biomarkers of DNA damage. The present study evaluates 1-hydroxypyrene concentrations and mutagenic activity in urine as biomarkers of exposure in non-smoking bus drivers in city and rural areas on a work day and a day off and in non-smoking mail carriers working outdoors (in the streets) and indoors (in the office). Twenty-four hour urine samples were collected on a working day and a day off from 60 non-smoking bus drivers in city and rural areas and from 88 non-smoking mail carriers working outdoors (in the streets) and indoors (in the office). The concentration of 1-hydroxypyrene was measured by means of HPLC and the mutagenic activity was assessed by the Ames assay with Salmonella tester strain YG1021 and S9 mix. The N-acetyltransferase (NAT2) phenotype was used as a biomarker for susceptibility to mutagenic/carcinogenic compounds. Bus drivers excreted more 1-hydroxypyrene in urine than did mail carriers. The differences were slightly smaller when NAT2 phenotype, cooking at home, exposure to vehicle exhaust, and performing physical exercise after work were included. The NAT2 slow acetylators had 29% (1.29 [CI: 1.15-1.98]) higher 1-hydroxypyrene concentrations in urine than the fast acetylators. Male bus drivers had 0.92 revertants/mol creatinine [CI: 0.37-1.47] and female bus drivers 1.90 revertants/mol creatinine [CI: 1.01-2.79] higher mutagenic activity in urine than mail carriers. The present study indicates that bus drivers are more exposed to polycyclic aromatic hydrocarbons (PAH) and mutagens than mail carriers. Mail carriers who worked outdoors had higher urinary concentration of 1-hydroxypyrene, a marker of exposure to PAH, than those working indoors. The individual levels of urinary mutagenic activity were not correlated to excretion of 1-hydroxypyrene. This might be due to the fact that the most potent mutagenic compounds in diesel exhaust are not PAH but dinitro-pyrenes. Among bus drivers, fast NAT2 acetylators had higher mutagenic activity in urine than slow NAT2 acetylators and female bus drivers had higher mutagenic activity than male bus drivers.

American Fuel Cell Bus Project Evaluation : Second Report

DOT National Transportation Integrated Search

2015-09-01

This report presents results of the American Fuel Cell Bus (AFCB) Project, a demonstration of fuel cell electric buses (FCEB) operating in the Coachella Valley area of California. The prototype AFCB was developed as part of the Federal Transit Admini...

Analysis of movable bus stop boarding and alighting areas.

DOT National Transportation Integrated Search

2013-05-01

This study explored the feasibility of using movable and reusable boarding and alighting (B&A) pads at bus stops. : Potential design alternatives in terms of materials and structural support for these pads were evaluated. The review : focused on the ...

Transient stability enhancement of modern power grid using predictive Wide-Area Monitoring and Control

NASA Astrophysics Data System (ADS)

Yousefian, Reza

This dissertation presents a real-time Wide-Area Control (WAC) designed based on artificial intelligence for large scale modern power systems transient stability enhancement. The WAC using the measurements available from Phasor Measurement Units (PMUs) at generator buses, monitors the global oscillations in the system and optimally augments the local excitation system of the synchronous generators. The complexity of the power system stability problem along with uncertainties and nonlinearities makes the conventional modeling non-practical or inaccurate. In this work Reinforcement Learning (RL) algorithm on the benchmark of Neural Networks (NNs) is used to map the nonlinearities of the system in real-time. This method different from both the centralized and the decentralized control schemes, employs a number of semi-autonomous agents to collaborate with each other to perform optimal control theory well-suited for WAC applications. Also, to handle the delays in Wide-Area Monitoring (WAM) and adapt the RL toward the robust control design, Temporal Difference (TD) is proposed as a solver for RL problem or optimal cost function. However, the main drawback of such WAC design is that it is challenging to determine if an offline trained network is valid to assess the stability of the power system once the system is evolved to a different operating state or network topology. In order to address the generality issue of NNs, a value priority scheme is proposed in this work to design a hybrid linear and nonlinear controllers. The algorithm so-called supervised RL is based on mixture of experts, where it is initialized by linear controller and as the performance and identification of the RL controller improves in real-time switches to the other controller. This work also focuses on transient stability and develops Lyapunov energy functions for synchronous generators to monitor the stability stress of the system. Using such energies as a cost function guarantees the convergence toward optimal post-fault solutions. These energy functions are developed on inter-area oscillations of the system identified online with Prony analysis. Finally, this work investigates the impacts of renewable energy resources, in specific Doubly Fed Induction Generator (DFIG)-based wind turbines, on power system transient stability and control. As the penetration of such resources is increased in transmission power system, neglecting the impacts of them will make the WAC design non-realistic. An energy function is proposed for DFIGs based on their dynamic performance in transient disturbances. Further, this energy is augmented to synchronous generators' energy as a global cost function, which is minimized by the WAC signals. We discuss the relative advantages and bottlenecks of each architecture and methodology using dynamic simulations of several test systems including a 2-area 8 bus system, IEEE 39 bus system, and IEEE 68 bus system in EMTP and real-time simulators. Being nonlinear-based, fast, accurate, and non-model based design, the proposed WAC system shows better transient and damping response when compared to conventional control schemes and local PSSs.

Transmission Loss Calculation using A and B Loss Coefficients in Dynamic Economic Dispatch Problem

NASA Astrophysics Data System (ADS)

Jethmalani, C. H. Ram; Dumpa, Poornima; Simon, Sishaj P.; Sundareswaran, K.

2016-04-01

This paper analyzes the performance of A-loss coefficients while evaluating transmission losses in a Dynamic Economic Dispatch (DED) Problem. The performance analysis is carried out by comparing the losses computed using nominal A loss coefficients and nominal B loss coefficients in reference with load flow solution obtained by standard Newton-Raphson (NR) method. Density based clustering method based on connected regions with sufficiently high density (DBSCAN) is employed in identifying the best regions of A and B loss coefficients. Based on the results obtained through cluster analysis, a novel approach in improving the accuracy of network loss calculation is proposed. Here, based on the change in per unit load values between the load intervals, loss coefficients are updated for calculating the transmission losses. The proposed algorithm is tested and validated on IEEE 6 bus system, IEEE 14 bus, system IEEE 30 bus system and IEEE 118 bus system. All simulations are carried out using SCILAB 5.4 (www.scilab.org) which is an open source software.

Health effects caused by primary fine particulate matter (PM2.5) emitted from buses in the Helsinki metropolitan area, Finland.

PubMed

Tainio, Marko; Tuomisto, Jouni T; Hänninen, Otto; Aarnio, Päivi; Koistinen, Kimmo J; Jantunen, Matti J; Pekkanen, Juha

2005-02-01

Fine particle (PM(2.5)) emissions from traffic have been associated with premature mortality. The current work compares PM(2.5)-induced mortality in alternative public bus transportation strategies as being considered by the Helsinki Metropolitan Area Council, Finland. The current bus fleet and transportation volume is compared to four alternative hypothetical bus fleet strategies for the year 2020: (1) the current bus fleet for 2020 traffic volume, (2) modern diesel buses without particle traps, (3) diesel buses with particle traps, and (4) buses using natural gas engines. The average population PM(2.5) exposure level attributable to the bus emissions was determined for the 1996-1997 situation using PM(2.5) exposure measurements including elemental composition from the EXPOLIS-Helsinki study and similar element-based source apportionment of ambient PM(2.5) concentrations observed in the ULTRA study. Average population exposure to particles originating from the bus traffic in the year 2020 is assumed to be proportional to the bus emissions in each strategy. Associated mortality was calculated using dose-response relationships from two large cohort studies on PM(2.5) mortality from the United States. Estimated number of deaths per year (90% confidence intervals in parenthesis) associated with primary PM(2.5) emissions from buses in Helsinki Metropolitan Area in 2020 were 18 (0-55), 9 (0-27), 4 (0-14), and 3 (0-8) for the strategies 1-4, respectively. The relative differences in the associated mortalities for the alternative strategies are substantial, but the number of deaths in the lowest alternative, the gas buses, is only marginally lower than what would be achieved by diesel engines equipped with particle trap technology. The dose-response relationship and the emission factors were identified as the main sources of uncertainty in the model.

Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration Results : Third Report

DOT National Transportation Integrated Search

2014-05-01

This report presents results of a demonstration of 12 fuel cell electric buses (FCEB) operating in Oakland, California. The FCEBs have a fuel cell dominant hybrid electric propulsion system in a series configuration. The bus manufacturerVan Hool...

Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration : Second Results Report

DOT National Transportation Integrated Search

2012-07-04

This report presents results of a demonstration of 12 new fuel cell electric buses (FCEB) operating in Oakland, California. The FCEBs have a fuel cell dominant hybrid electric propulsion system in a series configuration. The bus manufacturerVan Ho...

The use of UNIX in a real-time environment

NASA Technical Reports Server (NTRS)

Luken, R. D.; Simons, P. C.

1986-01-01

This paper describes a project to evaluate the feasibility of using commercial off-the-shelf hardware and the UNIX operating system, to implement a real-time control and monitor system. A functional subset of the Checkout, Control and Monitor System was chosen as the test bed for the project. The project consists of three separate architecture implementations: a local area bus network, a star network, and a central host. The motivation for this project stemmed from the need to find a way to implement real-time systems, without the cost burden of developing and maintaining custom hardware and unique software. This has always been accepted as the only option because of the need to optimize the implementation for performance. However, with the cost/performance of today's hardware, the inefficiencies of high-level languages and portable operating systems can be effectively overcome.

Private business perceptions of transportation issues and the island explorer bus system at Acadia National Park, Maine

Treesearch

Rea Brennan; Marc Edwards; John J. Daigle

2002-01-01

National Parks and communities that surround them often must work together to create the best possible experience for the visitors to the area. In the case of Acadia National Park in Maine, the surrounding communities and the park have worked together to face the issue of congestion in the area caused by too many automobiles. The Island Explorer Bus alternative...

Evaluation of the concentrations and distribution of carbonyl compounds in selected areas of a Brazilian bus terminal.

PubMed

de Mendonça Ochs, Soraya; de Almeida Furtado, Leonardo; Pereira Netto, Annibal Duarte

2015-06-01

This study describes the determination of 30 carbonyl compounds (CCs) in three areas (bus boarding platform, passenger circulation area, and a pastry shop) of the Presidente João Goulart Bus Terminal, located at Niterói City, RJ, Brazil, and in an open area 700 m distant from the terminal. Samples were collected using SEP-PAK cartridges impregnated with 2,4-dinitrophenylhydrazine, during May to July 2012. The hydrazones formed were analyzed using rapid resolution liquid chromatography with UV detection. The studied locations showed distinct profiles of distribution of CC. The circulation area, which is influenced by different pollution sources, presented an intermediate profile between that of the pastry shop and boarding platform. Formaldehyde and acetaldehyde were the most abundant CC, but acetaldehyde predominated in the pastry shop once it is a by-product of baking yeast fermentation. Samples taken in the pastry shop and circulation area showed significant concentrations of hexanaldehyde and nonanaldehyde emitted during cooking. The pastry shop showed the largest level of total CC among the studied areas followed by the circulation area, the boarding platform, and the open area.

Estimating Performance of Single Bus, Shared Memory Multiprocessors

DTIC Science & Technology

1987-05-01

Chandy78] K.M. Chandy, C.M. Sauer, "Approximate methods for analyzing queuing network models of computing systems," Computing Surveys, vol10 , no 3...Denning78] P. Denning, J. Buzen, "The operational analysis of queueing network models", Computing Sur- veys, vol10 , no 3, September 1978, pp 225-261

Racial disparities in travel time to radiotherapy facilities in the Atlanta metropolitan area

PubMed Central

Peipins, Lucy A.; Graham, Shannon; Young, Randall; Lewis, Brian; Flanagan, Barry

2018-01-01

Low-income women with breast cancer who rely on public transportation may have difficulty in completing recommended radiation therapy due to inadequate access to radiation facilities. Using a geographic information system (GIS) and network analysis we quantified spatial accessibility to radiation treatment facilities in the Atlanta, Georgia metropolitan area. We built a transportation network model that included all bus and rail routes and stops, system transfers and walk and wait times experienced by public transportation system travelers. We also built a private transportation network to model travel times by automobile. We calculated travel times to radiation therapy facilities via public and private transportation from a population-weighted center of each census tract located within the study area. We broadly grouped the tracts by low, medium and high household access to a private vehicle and by race. Facility service areas were created using the network model to map the extent of areal coverage at specified travel times (30, 45 and 60 min) for both public and private modes of transportation. The median public transportation travel time to the nearest radiotherapy facility was 56 min vs. approximately 8 min by private vehicle. We found that majority black census tracts had longer public transportation travel times than white tracts across all categories of vehicle access and that 39% of women in the study area had longer than 1 h of public transportation travel time to the nearest facility. In addition, service area analyses identified locations where the travel time barriers are the greatest. Spatial inaccessibility, especially for women who must use public transportation, is one of the barriers they face in receiving optimal treatment. PMID:23726213

Racial disparities in travel time to radiotherapy facilities in the Atlanta metropolitan area.

PubMed

Peipins, Lucy A; Graham, Shannon; Young, Randall; Lewis, Brian; Flanagan, Barry

2013-07-01

Low-income women with breast cancer who rely on public transportation may have difficulty in completing recommended radiation therapy due to inadequate access to radiation facilities. Using a geographic information system (GIS) and network analysis we quantified spatial accessibility to radiation treatment facilities in the Atlanta, Georgia metropolitan area. We built a transportation network model that included all bus and rail routes and stops, system transfers and walk and wait times experienced by public transportation system travelers. We also built a private transportation network to model travel times by automobile. We calculated travel times to radiation therapy facilities via public and private transportation from a population-weighted center of each census tract located within the study area. We broadly grouped the tracts by low, medium and high household access to a private vehicle and by race. Facility service areas were created using the network model to map the extent of areal coverage at specified travel times (30, 45 and 60 min) for both public and private modes of transportation. The median public transportation travel time to the nearest radiotherapy facility was 56 min vs. approximately 8 min by private vehicle. We found that majority black census tracts had longer public transportation travel times than white tracts across all categories of vehicle access and that 39% of women in the study area had longer than 1 h of public transportation travel time to the nearest facility. In addition, service area analyses identified locations where the travel time barriers are the greatest. Spatial inaccessibility, especially for women who must use public transportation, is one of the barriers they face in receiving optimal treatment. Published by Elsevier Ltd.

Multi-load Groups Coordinated Load Control Strategy Considering Power Network Constraints

NASA Astrophysics Data System (ADS)

Liu, Meng; Zhao, Binchao; Wang, Jun; Zhang, Guohui; Wang, Xin

2017-05-01

Loads with energy storage property can actively participate in power balance for power systems, this paper takes air conditioner as a controllable load example, proposing a multi-load groups coordinated load control strategy considering power network constraints. Firstly, two load control modes considering recovery of load diversity are designed, blocking power oscillation of aggregated air conditioners. As the same time, air conditioner temperature setpoint recovery control strategy is presented to avoid power recovery peak. Considering inherent characteristics of two load control modes, an coordinated load control mode is designed by combining the both. Basing on this, a multi-load groups coordinated load control strategy is proposed. During the implementing of load control, power network constraints should be satisfied. An indice which can reflect the security of power system operating is defined. By minimizing its value through optimization, the change of air conditioning loads’ aggregated power on each load bus can be calculated. Simulations are conducted on an air conditioners group and New England 10-generator 39-bus system, verifying the effectiveness of the proposed multi-load groups coordinated load control strategy considering power network constraints.

Equivalent Relaxations of Optimal Power Flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bose, S; Low, SH; Teeraratkul, T

2015-03-01

Several convex relaxations of the optimal power flow (OPF) problem have recently been developed using both bus injection models and branch flow models. In this paper, we prove relations among three convex relaxations: a semidefinite relaxation that computes a full matrix, a chordal relaxation based on a chordal extension of the network graph, and a second-order cone relaxation that computes the smallest partial matrix. We prove a bijection between the feasible sets of the OPF in the bus injection model and the branch flow model, establishing the equivalence of these two models and their second-order cone relaxations. Our results implymore » that, for radial networks, all these relaxations are equivalent and one should always solve the second-order cone relaxation. For mesh networks, the semidefinite relaxation and the chordal relaxation are equally tight and both are strictly tighter than the second-order cone relaxation. Therefore, for mesh networks, one should either solve the chordal relaxation or the SOCP relaxation, trading off tightness and the required computational effort. Simulations are used to illustrate these results.« less

Evaluation of transit operations : data applications of Tri-Met's automated bus dispatching system

DOT National Transportation Integrated Search

2001-02-01

This paper presents an analysis of operating performance for Tri-Met, the transit provider for the Portland, Oregon metropolitan area. The analysis draws on data recovered by Tri-Met's automated Bus Dispatching System (BDS) and focuses on two main su...

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

DOT National Transportation Integrated Search

2013-01-01

SunLine Transit Agency provides public transit services to the Coachella Valley area of California. SunLine has demonstrated hydrogen and fuel cell bus technologies for more than 10 years. In May 2010, SunLine began demonstrating the advanced technol...

Activities of four bus terminals of Semarang City gateway and the related GHG emission

NASA Astrophysics Data System (ADS)

Huboyo, H. S.; Wardhana, I. W.; Sutrisno, E.; Wangi, L. S.; Lina, R. A.

2018-01-01

The activities of the bus terminal, including loading-unloading passengers, bus idling, and bus movements at the terminal, will emit GHG’s emission. This research analyzes GHG emission from four terminals, i.e., Mangkang, Terboyo, Penggaron, and Sukun in Semarang City. The emission was estimated by observing detail activities of public transport means, especially for moving and idling time. The emission was calculated by Tier 2 method based on the vehicle type as well as fuel consumption. The highest CO2e during vehicle movements at Sukun area was contributed by large bus about 2.08 tons/year, while at Terboyo terminal was contributed by medium bus about 347.97 tons/year. At Mangkang terminals, the highest emission for vehicle movements was attributed by medium bus as well of about 53.18 tons/year. At last, Penggaron terminal’s highest GHG emission was attributed by BRT about 26.47 tons/year. During idling time, the highest contributor to CO2e was the large bus at the three terminals, i.e., Sukun of 43.53 tons/year, Terboyo of 196.56 tons/year, and Mangkang of 84.26 tons/year, while at Penggaron, BRT dominated with CO2e of 26.47 tons/year. The management of public transport in terminals is crucial to mitigate the emission related to bus terminals activities.

Get off the bus: sound strategy for injury prevention during a tornado?

PubMed

Comstock, R Dawn; Mallonee, Sue

2005-01-01

On 08 May 2003, a tornado categorized as an F-3 on the Fujita Tornado Scale (the "F Scale") struck an Oklahoma City, Oklahoma commuter bus carrying 24 passengers. The driver evacuated several passengers before the tornado struck. The tornado rolled the bus, and pelted it with debris. A case-series investigation of tornado-related injuries was conducted among passengers who were evacuated to a ditch and those who remained on the bus when the tornado struck. Nineteen of 24 passengers sought care for injuries at hospital emergency departments (injury rate = 79.2%). While a greater number of passengers who were outside the bus when the tornado struck (11) sought care for injuries than did those who remained on the bus (8); passengers outside of the bus suffered fewer injuries than did those who remained on the bus (median number of injuries 3 versus 4), and their injuries were less severe (median injury severity score (ISS) 1 versus 4). For persons caught in motor vehicles during tornado events, this study supports currently accepted recommendations to immediately evacuate and lie in a low-lying area away from motor vehicles if other shelter is unavailable. However, generalizing the experience of bus passengers to automobile drivers might be inappropriate because buses lack the safety features that might protect automobile drivers from tornado-related injuries.

Reducing transit bus emissions: Alternative fuels or traffic operations?

NASA Astrophysics Data System (ADS)

Alam, Ahsan; Hatzopoulou, Marianne

2014-06-01

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.

Protocol for communications in potentially noisy environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyd, Gerlad M.; Farrow, Jeffrey

2016-02-09

A communications protocol that is designed for transmission of data in networks that are subjected to harsh conditions is described herein. A network includes a plurality of devices, where the devices comprise respective nodes. The nodes are in communication with one another by way of a central network hub. The protocol causes the nodes to transmit data over a network bus at different data rates depending upon whether the nodes are operating normally or an arbitration procedure has been invoked.

Synchrophasor Sensor Networks for Grid Communication and Protection.

PubMed

Gharavi, Hamid; Hu, Bin

2017-07-01

This paper focuses primarily on leveraging synchronized current/voltage amplitudes and phase angle measurements to foster new categories of applications, such as improving the effectiveness of grid protection and minimizing outage duration for distributed grid systems. The motivation for such an application arises from the fact that with the support of communication, synchronized measurements from multiple sites in a grid network can greatly enhance the accuracy and timeliness of identifying the source of instabilities. The paper first provides an overview of synchrophasor networks and then presents techniques for power quality assessment, including fault detection and protection. To achieve this we present a new synchrophasor data partitioning scheme that is based on the formation of a joint space and time observation vector. Since communication is an integral part of synchrophasor networks, the newly adopted wireless standard for machine-to-machine (M2M) communication, known as IEEE 802.11ah, has been investigated. The paper also presents a novel implementation of a hardware in the loop testbed for real-time performance evaluation. The purpose is to illustrate the use of both hardware and software tools to verify the performance of synchrophasor networks under more realistic environments. The testbed is a combination of grid network modeling, and an Emulab-based communication network. The combined grid and communication network is then used to assess power quality for fault detection and location using the IEEE 39-bus and 390-bus systems.

Synchrophasor Sensor Networks for Grid Communication and Protection

PubMed Central

Gharavi, Hamid

2017-01-01

This paper focuses primarily on leveraging synchronized current/voltage amplitudes and phase angle measurements to foster new categories of applications, such as improving the effectiveness of grid protection and minimizing outage duration for distributed grid systems. The motivation for such an application arises from the fact that with the support of communication, synchronized measurements from multiple sites in a grid network can greatly enhance the accuracy and timeliness of identifying the source of instabilities. The paper first provides an overview of synchrophasor networks and then presents techniques for power quality assessment, including fault detection and protection. To achieve this we present a new synchrophasor data partitioning scheme that is based on the formation of a joint space and time observation vector. Since communication is an integral part of synchrophasor networks, the newly adopted wireless standard for machine-to-machine (M2M) communication, known as IEEE 802.11ah, has been investigated. The paper also presents a novel implementation of a hardware in the loop testbed for real-time performance evaluation. The purpose is to illustrate the use of both hardware and software tools to verify the performance of synchrophasor networks under more realistic environments. The testbed is a combination of grid network modeling, and an Emulab-based communication network. The combined grid and communication network is then used to assess power quality for fault detection and location using the IEEE 39-bus and 390-bus systems. PMID:28890553

Available Transfer Capability Determination Using Hybrid Evolutionary Algorithm

NASA Astrophysics Data System (ADS)

Jirapong, Peeraool; Ongsakul, Weerakorn

2008-10-01

This paper proposes a new hybrid evolutionary algorithm (HEA) based on evolutionary programming (EP), tabu search (TS), and simulated annealing (SA) to determine the available transfer capability (ATC) of power transactions between different control areas in deregulated power systems. The optimal power flow (OPF)-based ATC determination is used to evaluate the feasible maximum ATC value within real and reactive power generation limits, line thermal limits, voltage limits, and voltage and angle stability limits. The HEA approach simultaneously searches for real power generations except slack bus in a source area, real power loads in a sink area, and generation bus voltages to solve the OPF-based ATC problem. Test results on the modified IEEE 24-bus reliability test system (RTS) indicate that ATC determination by the HEA could enhance ATC far more than those from EP, TS, hybrid TS/SA, and improved EP (IEP) algorithms, leading to an efficient utilization of the existing transmission system.

Telecommunication Platforms for Transmitting Sensor Data over Communication Networks—State of the Art and Challenges

PubMed Central

Staniec, Kamil; Habrych, Marcin

2016-01-01

The importance of constructing wide-area sensor networks for holistic environmental state evaluation has been demonstrated. A general structure of such a network has been presented with distinction of three segments: local (based on ZigBee, Ethernet and ModBus techniques), core (base on cellular technologies) and the storage/application. The implementation of these techniques requires knowledge of their technical limitations and electromagnetic compatibility issues. The former refer to ZigBee performance degradation in multi-hop transmission, whereas the latter are associated with the common electromagnetic spectrum sharing with other existing technologies or with undesired radiated emissions generated by the radio modules of the sensor network. In many cases, it is also necessary to provide a measurement station with autonomous energy source, such as solar. As stems from measurements of the energetic efficiency of these sources, one should apply them with care and perform detailed power budget since their real performance may turn out to be far from expected. This, in turn, may negatively affect—in particular—the operation of chemical sensors implemented in the network as they often require additional heating. PMID:27447633

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

DOT National Transportation Integrated Search

2012-05-01

SunLine Transit Agency provides public transit services to the Coachella Valley area of California. SunLine has demonstrated hydrogen and fuel cell bus technologies for more than 10 years. This report describes operations at SunLine for a prototype f...

Compressed Natural Gas (CNG) Transit Bus Experience Survey: April 2009--April 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, R.; Horne, D. B.

2010-09-01

This survey was commissioned by the U.S. Department of Energy (DOE) and the National Renewable Energy Laboratory (NREL) to collect and analyze experiential data and information from a cross-section of U.S. transit agencies with varying degrees of compressed natural gas (CNG) bus and station experience. This information will be used to assist DOE and NREL in determining areas of success and areas where further technical or other assistance might be required, and to assist them in focusing on areas judged by the CNG transit community as priority items.

Theoretical Comparison of Fixed Route Bus and Flexible Route Subscription Bus Feeder Service in Low Density Areas

DOT National Transportation Integrated Search

1975-03-01

parametric variation of demand density was used to compare service level and cost of two alternative systems for providing low density feeder service. Supply models for fixed route and flexible route service were developed and applied to determine ra...

High-Speed Ring Bus

NASA Technical Reports Server (NTRS)

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

2010-01-01

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

A Multi-agent Based Cooperative Voltage and Reactive Power Control

NASA Astrophysics Data System (ADS)

Ishida, Masato; Nagata, Takeshi; Saiki, Hiroshi; Shimada, Ikuhiko; Hatano, Ryousuke

In order to maintain system voltage within the optimal range and prevent voltage instability phenomena before they occur, a variety of phase modifying equipment is installed in optimal locations throughout the power system network and a variety of methods of voltage reactive control are employed. The proposed system divided the traditional method to control voltage and reactive power into two sub problems; “voltage control” to adjust the secondary bus voltage of substations, and “reactive power control” to adjust the primary bus voltage. In this system, two types of agents are installed in substations in order to cooperate “voltage control” and “reactive power control”. In order to verify the performance of the proposed method, it has been applied to the model network system. The results confirm that our proposed method is able to control violent fluctuations in load.

Global system data bus using the Digital Autonomous Terminal Access Communication protocol

NASA Technical Reports Server (NTRS)

Holmes, David C. E.

1986-01-01

Modern digital avionic systems with distributed processing require networking to connect the many elements. Digital Autonomous Terminal Access Communication (DATAC) is one of many such networks. DATAC has been implemented on the Transport Systems Research Vehicle (TSRV), a Boeing 737 aircraft operated by the National Aeronautics and Space Administration's Advanced Transport Operating Systems Program Office (ATOPS). This paper presents the TSRV implementation of the DATAC bus, a description of the DATAC system, a synchronization mechanism, details of data flow throughout the system, and a discussion of the modes available with DATAC. Numerous flight tests have been conducted using DATAC as the only means of communication between systems with outstanding results. DATAC is now an integral part of the TSRV and is expected to satisfy near term as well as future requirements for growth and flexibility.

Safety models incorporating graph theory based transit indicators.

PubMed

Quintero, Liliana; Sayed, Tarek; Wahba, Mohamed M

2013-01-01

There is a considerable need for tools to enable the evaluation of the safety of transit networks at the planning stage. One interesting approach for the planning of public transportation systems is the study of networks. Network techniques involve the analysis of systems by viewing them as a graph composed of a set of vertices (nodes) and edges (links). Once the transport system is visualized as a graph, various network properties can be evaluated based on the relationships between the network elements. Several indicators can be calculated including connectivity, coverage, directness and complexity, among others. The main objective of this study is to investigate the relationship between network-based transit indicators and safety. The study develops macro-level collision prediction models that explicitly incorporate transit physical and operational elements and transit network indicators as explanatory variables. Several macro-level (zonal) collision prediction models were developed using a generalized linear regression technique, assuming a negative binomial error structure. The models were grouped into four main themes: transit infrastructure, transit network topology, transit route design, and transit performance and operations. The safety models showed that collisions were significantly associated with transit network properties such as: connectivity, coverage, overlapping degree and the Local Index of Transit Availability. As well, the models showed a significant relationship between collisions and some transit physical and operational attributes such as the number of routes, frequency of routes, bus density, length of bus and 3+ priority lanes. Copyright © 2012 Elsevier Ltd. All rights reserved.

Towards smart mobility in urban spaces: Bus tracking and information application

NASA Astrophysics Data System (ADS)

Yue, Wong Seng; Chye, Koh Keng; Hoy, Cheong Wan

2017-10-01

Smart city can be defined as an urban space with complete and advanced infrastructure, intelligent networks and platforms, with millions of sensors among which people themselves and their mobile devices. Urban mobility is one of the global smart city project which offers traffic management in real-time, management of passenger transport means, tracking applications and logistics, car sharing services, car park management and more smart mobility services. Due to the frustrated waiting time for the arrival of buses and the difficulty of accessing shuttle bus-related information in a one-stop centre, bus tracking and information application (BTA) is one the proposed solutions to solve the traffic problems in urban spaces. This paper is aimed to design and develop a bus tracking and information application in a selected city in Selangor state, Malaysia. Next, this application also provides an alternative to design public transport tracking and information application for the urban places in Malaysia. Furthermore, the application also provides a smart solution for the management of public infrastructures and urban facilities in Malaysia in future.

Multipurpose satellite bus (MPS)

NASA Technical Reports Server (NTRS)

1991-01-01

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

Critical incident management guidelines

DOT National Transportation Integrated Search

1998-07-01

The public transportation network in the United States includes 508 bus and rail agencies and 15 commuter railroads providing 22 million trips daily, 8 billion trips annually. These agencies employ almost 300,000 people and provide approximately 41 b...

CCSDS Time-Critical Onboard Networking Service

NASA Technical Reports Server (NTRS)

Parkes, Steve; Schnurr, Rick; Marquart, Jane; Menke, Greg; Ciccone, Massimiliano

2006-01-01

The Consultative Committee for Space Data Systems (CCSDS) is developing recommendations for communication services onboard spacecraft. Today many different communication buses are used on spacecraft requiring software with the same basic functionality to be rewritten for each type of bus. This impacts on the application software resulting in custom software for almost every new mission. The Spacecraft Onboard Interface Services (SOIS) working group aims to provide a consistent interface to various onboard buses and sub-networks, enabling a common interface to the application software. The eventual goal is reusable software that can be easily ported to new missions and run on a range of onboard buses without substantial modification. The system engineer will then be able to select a bus based on its performance, power, etc and be confident that a particular choice of bus will not place excessive demands on software development. This paper describes the SOIS Intra-Networking Service which is designed to enable data transfer and multiplexing of a variety of internetworking protocols with a range of quality of service support, over underlying heterogeneous data links. The Intra-network service interface provides users with a common Quality of Service interface when transporting data across a variety of underlying data links. Supported Quality of Service (QoS) elements include: Priority, Resource Reservation and Retry/Redundancy. These three QoS elements combine and map into four TCONS services for onboard data communications: Best Effort, Assured, Reserved, and Guaranteed. Data to be transported is passed to the Intra-network service with a requested QoS. The requested QoS includes the type of service, priority and where appropriate, a channel identifier. The data is de-multiplexed, prioritized, and the required resources for transport are allocated. The data is then passed to the appropriate data link for transfer across the bus. The SOIS supported data links may inherently provide the quality of service support requested by the intra-network layer. In the case where the data link does not have the required level of support, the missing functionality is added by SOIS. As a result of this architecture, re-usable software applications can be designed and used across missions thereby promoting common mission operations. In addition, the protocol multiplexing function enables the blending of multiple onboard networks. This paper starts by giving an overview of the SOIS architecture in section 11, illustrating where the TCONS services fit into the overall architecture. It then describes the quality of service approach adopted, in section III. The prototyping efforts that have been going on are introduced in section JY. Finally, in section V the current status of the CCSDS recommendations is summarized.

A Conceptual Approach for Optimising Bus Stop Spacing

NASA Astrophysics Data System (ADS)

Johar, Amita; Jain, S. S.; Garg, P. k.

2017-06-01

An efficient public transportation system is essential of any country. The growth, development and shape of the urban areas are mainly due to availability of good transportation (Shah et al. in Inst Town Plan India J 5(3):50-59, 1). In developing countries, like India, travel by local bus in a city is very common. The accidents, congestion, pollution and appropriate location of bus stops are the major problems arising in metropolitan cities. Among all the metropolitan cities in India, Delhi has highest percentage of growth of population and vehicles. Therefore, it is important to adopt efficient and effective ways to improve mobility in different metropolitan cities in order to overcome the problem and to reduce the number of private vehicles on the road. The primary objective of this paper is to present a methodology for developing a model for optimum bus stop spacing (OBSS). It describes the evaluation of existing urban bus route, data collection, development of model for optimizing urban bus route and application of model. In this work, the bus passenger generalized cost method is used to optimize the spacing between bus stops. For the development of model, a computer program is required to be written. The applicability of the model has been evaluated by taking the data of urban bus route of Delhi Transport Corporation (DTC) in Excel sheet in first phase. Later on, it is proposed to develop a programming in C++ language. The developed model is expected to be useful to transport planner for rational design of the spacing of bus stops to save travel time and to generalize operating cost. After analysis it is found that spacing between the bus stop comes out to be between 250 and 500 m. The Proposed Spacing of bus stops is done considering the points that they don't come nearer to metro/rail station, entry or exit of flyover and near traffic signal.

Prevalence of and factors associated with distraction among public transit bus drivers

PubMed Central

Griffin, Russell; Huisingh, Carrie; McGwin, Gerald

2015-01-01

Objective Recent research has suggested that driver distraction is a major cause of driving performance impairment and motor vehicle collisions. Research on the topic has focused on passenger vehicles, with studies suggesting that drivers may be distracted nearly 33% of the time spent driving. To date, no study has examined the prevalence of distraction specifically among public transit bus drivers. Methods Over a three-month period, trained investigators observed and recorded distraction behaviors of bus drivers. Distraction prevalence was compared by route characteristics (e.g., geographic area, travel speed) using chi-square test. A general estimating equation logistic regression was used to estimate p-values for distraction prevalence by driver demographics. Results Overall, there was a 39% prevalence of distraction. The most prevalent distractions were due to interactions with another passenger. Distractions were more prevalent among drivers <30 years of age or ≥50 years of age, on city streets or highways (relative to residential streets), and when there were more than 20 passengers. Distractions were the least prevalent in suburban areas, with the highest prevalence observed in city centers and rural areas. Conclusions Driver distraction is a common problem for public transit bus drivers, mainly due to other passengers. Drivers should be educated on the hazards of distracted driving and on ways to avoid distraction. PMID:24433192

Assessment of the applicability of cooperative vehicle-highway automation systems (CVHAS) to bus transit and intermodal freight : case study feasibility analyses in the Metropolitan Chicago Region.

DOT National Transportation Integrated Search

2008-12-01

This report presents the results of its performance assessment of the feasibility of applying cooperative vehicle- highway automation systems (CVHAS) to bus transit and freight movements in the metropolitan Chicago area. : CVHAS are systems that prov...

Improvement of multiprocessing performance by using optical centralized shared bus

NASA Astrophysics Data System (ADS)

Han, Xuliang; Chen, Ray T.

2004-06-01

With the ever-increasing need to solve larger and more complex problems, multiprocessing is attracting more and more research efforts. One of the challenges facing the multiprocessor designers is to fulfill in an effective manner the communications among the processes running in parallel on multiple multiprocessors. The conventional electrical backplane bus provides narrow bandwidth as restricted by the physical limitations of electrical interconnects. In the electrical domain, in order to operate at high frequency, the backplane topology has been changed from the simple shared bus to the complicated switched medium. However, the switched medium is an indirect network. It cannot support multicast/broadcast as effectively as the shared bus. Besides the additional latency of going through the intermediate switching nodes, signal routing introduces substantial delay and considerable system complexity. Alternatively, optics has been well known for its interconnect capability. Therefore, it has become imperative to investigate how to improve multiprocessing performance by utilizing optical interconnects. From the implementation standpoint, the existing optical technologies still cannot fulfill the intelligent functions that a switch fabric should provide as effectively as their electronic counterparts. Thus, an innovative optical technology that can provide sufficient bandwidth capacity, while at the same time, retaining the essential merits of the shared bus topology, is highly desirable for the multiprocessing performance improvement. In this paper, the optical centralized shared bus is proposed for use in the multiprocessing systems. This novel optical interconnect architecture not only utilizes the beneficial characteristics of optics, but also retains the desirable properties of the shared bus topology. Meanwhile, from the architecture standpoint, it fits well in the centralized shared-memory multiprocessing scheme. Therefore, a smooth migration with substantial multiprocessing performance improvement is expected. To prove the technical feasibility from the architecture standpoint, a conceptual emulation of the centralized shared-memory multiprocessing scheme is demonstrated on a generic PCI subsystem with an optical centralized shared bus.

The Center of Attention

NASA Technical Reports Server (NTRS)

2000-01-01

New Hampshire-based Creare, Inc. used a NASA SBIR contract with Dryden to develop "middleware" known commercially as DataTurbine. DataTurbine acts as "glueware" allowing communication between dissimilar computer platforms and analysis, storage and acquisition of shared data. DataTurbine relies on Ring Buffered Network Bus technology, which is a software server providing a buffered network path between suppliers and consumers of information.

Efficient algorithm for locating and sizing series compensation devices in large power transmission grids: II. Solutions and applications

DOE PAGES

Frolov, Vladimir; Backhaus, Scott; Chertkov, Misha

2014-10-01

In a companion manuscript, we developed a novel optimization method for placement, sizing, and operation of Flexible Alternating Current Transmission System (FACTS) devices to relieve transmission network congestion. Specifically, we addressed FACTS that provide Series Compensation (SC) via modification of line inductance. In this manuscript, this heuristic algorithm and its solutions are explored on a number of test cases: a 30-bus test network and a realistically-sized model of the Polish grid (~ 2700 nodes and ~ 3300 lines). The results on the 30-bus network are used to study the general properties of the solutions including non-locality and sparsity. The Polishmore » grid is used as a demonstration of the computational efficiency of the heuristics that leverages sequential linearization of power flow constraints and cutting plane methods that take advantage of the sparse nature of the SC placement solutions. Using these approaches, the algorithm is able to solve an instance of Polish grid in tens of seconds. We explore the utility of the algorithm by analyzing transmission networks congested by (a) uniform load growth, (b) multiple overloaded configurations, and (c) sequential generator retirements.« less

IEEE 1393 Spaceborne Fiber Optic Data Bus: A Standard Approach to On-Board Payload Data Handling Networks for the AIAA Space Technology Conference and Exposition "Partnering in the 21th Century"

NASA Technical Reports Server (NTRS)

Andrucyk, Dennis J.; Orlando, Fred J.; Chalfant, Charles H.

1999-01-01

The Spaceborne Fiber Optic Data Bus (SFODB) is the next generation in on-board data handling networks. It will do for high speed payloads what SAE 1773 has done for on-board command and telemetry systems. That is, it will significantly reduce the cost of payload development, integration and test through interface standardization. As defined in IEEE 1393, SFODB is a 1 Gb/s, fiber optic network specifically designed to support the real-time, on-board data handling requirements of remote sensing spacecraft. The network is highly reliable, fault tolerant, 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. SFODB was developed jointly by DoD and NASA GSFC to meet the on-board data handling needs of Remote Sensing satellites. This jointly funded project produced a complete set of flight transmitters, receivers and protocol ASICS; a complete Development & Evaluation System; and, the IEEE 1393 standard.

Efficient Algorithm for Locating and Sizing Series Compensation Devices in Large Transmission Grids: Solutions and Applications (PART II)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frolov, Vladimir; Backhaus, Scott N.; Chertkov, Michael

2014-01-14

In a companion manuscript, we developed a novel optimization method for placement, sizing, and operation of Flexible Alternating Current Transmission System (FACTS) devices to relieve transmission network congestion. Specifically, we addressed FACTS that provide Series Compensation (SC) via modification of line inductance. In this manuscript, this heuristic algorithm and its solutions are explored on a number of test cases: a 30-bus test network and a realistically-sized model of the Polish grid (~2700 nodes and ~3300 lines). The results on the 30-bus network are used to study the general properties of the solutions including non-locality and sparsity. The Polish grid ismore » used as a demonstration of the computational efficiency of the heuristics that leverages sequential linearization of power flow constraints and cutting plane methods that take advantage of the sparse nature of the SC placement solutions. Using these approaches, the algorithm is able to solve an instance of Polish grid in tens of seconds. We explore the utility of the algorithm by analyzing transmission networks congested by (a) uniform load growth, (b) multiple overloaded configurations, and (c) sequential generator retirements« less

The school bus routing and scheduling problem with transfers

PubMed Central

Doerner, Karl F.; Parragh, Sophie N.

2015-01-01

In this article, we study the school bus routing and scheduling problem with transfers arising in the field of nonperiodic public transportation systems. It deals with the transportation of pupils from home to their school in the morning taking the possibility that pupils may change buses into account. Allowing transfers has several consequences. On the one hand, it allows more flexibility in the bus network structure and can, therefore, help to reduce operating costs. On the other hand, transfers have an impact on the service level: the perceived service quality is lower due to the existence of transfers; however, at the same time, user ride times may be reduced and, thus, transfers may also have a positive impact on service quality. The main objective is the minimization of the total operating costs. We develop a heuristic solution framework to solve this problem and compare it with two solution concepts that do not consider transfers. The impact of transfers on the service level in terms of time loss (or user ride time) and the number of transfers is analyzed. Our results show that allowing transfers reduces total operating costs significantly while average and maximum user ride times are comparable to solutions without transfers. © 2015 Wiley Periodicals, Inc. NETWORKS, Vol. 65(2), 180–203 2015 PMID:28163329

Sociospatial distribution of access to facilities for moderate and vigorous intensity physical activity in Scotland by different modes of transport

PubMed Central

2012-01-01

Background People living in neighbourhoods of lower socioeconomic status have been shown to have higher rates of obesity and a lower likelihood of meeting physical activity recommendations than their more affluent counterparts. This study examines the sociospatial distribution of access to facilities for moderate or vigorous intensity physical activity in Scotland and whether such access differs by the mode of transport available and by Urban Rural Classification. Methods A database of all fixed physical activity facilities was obtained from the national agency for sport in Scotland. Facilities were categorised into light, moderate and vigorous intensity activity groupings before being mapped. Transport networks were created to assess the number of each type of facility accessible from the population weighted centroid of each small area in Scotland on foot, by bicycle, by car and by bus. Multilevel modelling was used to investigate the distribution of the number of accessible facilities by small area deprivation within urban, small town and rural areas separately, adjusting for population size and local authority. Results Prior to adjustment for Urban Rural Classification and local authority, the median number of accessible facilities for moderate or vigorous intensity activity increased with increasing deprivation from the most affluent or second most affluent quintile to the most deprived for all modes of transport. However, after adjustment, the modelling results suggest that those in more affluent areas have significantly higher access to moderate and vigorous intensity facilities by car than those living in more deprived areas. Conclusions The sociospatial distributions of access to facilities for both moderate intensity and vigorous intensity physical activity were similar. However, the results suggest that those living in the most affluent neighbourhoods have poorer access to facilities of either type that can be reached on foot, by bicycle or by bus than those living in less affluent areas. This poorer access from the most affluent areas appears to be reversed for those with access to a car. PMID:22568969

Heuristic Optimization Approach to Selecting a Transport Connection in City Public Transport

NASA Astrophysics Data System (ADS)

Kul'ka, Jozef; Mantič, Martin; Kopas, Melichar; Faltinová, Eva; Kachman, Daniel

2017-02-01

The article presents a heuristic optimization approach to select a suitable transport connection in the framework of a city public transport. This methodology was applied on a part of the public transport in Košice, because it is the second largest city in the Slovak Republic and its network of the public transport creates a complex transport system, which consists of three different transport modes, namely from the bus transport, tram transport and trolley-bus transport. This solution focused on examining the individual transport services and their interconnection in relevant interchange points.

Future Data Communication Architectures for Safety Critical Aircraft Cabin Systems

NASA Astrophysics Data System (ADS)

Berkhahn, Sven-Olaf

2012-05-01

The cabin of modern aircraft is subject to increasing demands for fast reconfiguration and hence flexibility. These demands require studies for new network architectures and technologies of the electronic cabin systems, which consider also weight and cost reductions as well as safety constraints. Two major approaches are in consideration to reduce the complex and heavy wiring harness: the usage of a so called hybrid data bus technology, which enables the common usage of the same data bus for several electronic cabin systems with different safety and security requirements and the application of wireless data transfer technologies for electronic cabin systems.

SAE for the prediction of road traffic status from taxicab operating data and bus smart card data

NASA Astrophysics Data System (ADS)

Zhengfeng, Huang; Pengjun, Zheng; Wenjun, Xu; Gang, Ren

Road traffic status is significant for trip decision and traffic management, and thus should be predicted accurately. A contribution is that we consider multi-modal data for traffic status prediction than only using single source data. With the substantial data from Ningbo Passenger Transport Management Sector (NPTMS), we wished to determine whether it was possible to develop Stacked Autoencoders (SAEs) for accurately predicting road traffic status from taxicab operating data and bus smart card data. We show that SAE performed better than linear regression model and Back Propagation (BP) neural network for determining the relationship between road traffic status and those factors. In a 26-month data experiment using SAE, we show that it is possible to develop highly accurate predictions (91% test accuracy) of road traffic status from daily taxicab operating data and bus smart card data.

Multimode marine engine room simulation system based on field bus technology

NASA Astrophysics Data System (ADS)

Zheng, Huayao; Deng, Linlin; Guo, Yi

2003-09-01

Developing multi mode MER (Marine Engine Room) Labs is the main work in Marine Simulation Center, which is the key lab of Communication Ministry of China. It includes FPP (Fixed Pitch Propeller) and CPP (Controllable Pitch Propeller) mode MER simulation systems, integrated electrical propulsion mode MER simulation system, physical mode MER lab, etc. FPP mode simulation system, which was oriented to large container ship, had been completed since 1999, and got second level of Shanghai Municipal Science and Technical Progress award. This paper mainly introduces the recent development and achievements of Marine Simulation Center. Based on the Lon Works field bus, the structure characteristics and control strategies of completely distributed intelligent control network are discussed. The experiment mode of multi-nodes field bus detection and control system is described. Besides, intelligent fault diagnosis technology about some mechatronics integration control systems explored is also involved.

Rochester New York Integrated Transit Demonstration : Volume 3. Appendices.

DOT National Transportation Integrated Search

1979-03-01

The Rochester Integrated Transit Demonstration (RITD) was designed to assess the roles of demand-responsive transit services in a regionwide transit system that includes an extensive fixed-route bus network. The demonstration extended transit service...

Rochester New York Integrated Transit Demonstration : Volume 2. Evaluation Report.

DOT National Transportation Integrated Search

1979-03-01

The Rochester Integrated Transit Demonstration (RITD) was designed to assess the roles of demand-responsive transit services in a regionwide transit system that includes an extensive fixed-route bus network. The demonstration extended transit service...

Rochester New York Integrated Transit Demonstration : Volume 1. Executive Summary.

DOT National Transportation Integrated Search

1979-03-01

The Rochester Integrated Transit Demonstration (RITD) was designed to assess the roles of demand-responsive transit services in a regionwide transit system that includes an extensive fixed-route bus network. The demonstration extended transit service...

The Researching on Evaluation of Automatic Voltage Control Based on Improved Zoning Methodology

NASA Astrophysics Data System (ADS)

Xiao-jun, ZHU; Ang, FU; Guang-de, DONG; Rui-miao, WANG; De-fen, ZHU

2018-03-01

According to the present serious phenomenon of increasing size and structure of power system, hierarchically structured automatic voltage control(AVC) has been the researching spot. In the paper, the reduced control model is built and the adaptive reduced control model is researched to improve the voltage control effect. The theories of HCSD, HCVS, SKC and FCM are introduced and the effect on coordinated voltage regulation caused by different zoning methodologies is also researched. The generic framework for evaluating performance of coordinated voltage regulation is built. Finally, the IEEE-96 stsyem is used to divide the network. The 2383-bus Polish system is built to verify that the selection of a zoning methodology affects not only the coordinated voltage regulation operation, but also its robustness to erroneous data and proposes a comprehensive generic framework for evaluating its performance. The New England 39-bus network is used to verify the adaptive reduced control models’ performance.

American Fuel Cell Bus Project Evaluation. Second Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eudy, Leslie; Post, Matthew

2015-09-01

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pickerell, D.H.; Abkowitz, M.; Tozzi, J.

The 9 papers in the report deal with the following areas: Federal operating assistance for urban mass transit; a decade of experience; transit route characteristics and headway-based reliability control; day-of-week and part-of-month variation in bus ridership; job satisfaction and transit operator recognition programs; results of a survey of muni operators; bus marketing costs: the experience of 18 section 15 reporters from 1981 to 1983; prospects for differential transit pricing in the United States; an initial analysis of total factor productivity for public-transit coordination of transportation resources: the Georgia experience; absenteeism, accidents, and attrition: part-time versus full-time bus drivers.

Circuit for Communication Over Power Lines

NASA Technical Reports Server (NTRS)

Krasowski, Michael J.; Prokop, Normal F.; Greer, Lawrence C., III; Nappier, Jennifer

2011-01-01

Many distributed systems share common sensors and instruments along with a common power line supplying current to the system. A communication technique and circuit has been developed that allows for the simple inclusion of an instrument, sensor, or actuator node within any system containing a common power bus. Wherever power is available, a node can be added, which can then draw power for itself, its associated sensors, and actuators from the power bus all while communicating with other nodes on the power bus. The technique modulates a DC power bus through capacitive coupling using on-off keying (OOK), and receives and demodulates the signal from the DC power bus through the same capacitive coupling. The circuit acts as serial modem for the physical power line communication. The circuit and technique can be made of commercially available components or included in an application specific integrated circuit (ASIC) design, which allows for the circuit to be included in current designs with additional circuitry or embedded into new designs. This device and technique moves computational, sensing, and actuation abilities closer to the source, and allows for the networking of multiple similar nodes to each other and to a central processor. This technique also allows for reconfigurable systems by adding or removing nodes at any time. It can do so using nothing more than the in situ power wiring of the system.

Distributed multiport memory architecture

NASA Technical Reports Server (NTRS)

Kohl, W. H. (Inventor)

1983-01-01

A multiport memory architecture is diclosed for each of a plurality of task centers connected to a command and data bus. Each task center, includes a memory and a plurality of devices which request direct memory access as needed. The memory includes an internal data bus and an internal address bus to which the devices are connected, and direct timing and control logic comprised of a 10-state ring counter for allocating memory devices by enabling AND gates connected to the request signal lines of the devices. The outputs of AND gates connected to the same device are combined by OR gates to form an acknowledgement signal that enables the devices to address the memory during the next clock period. The length of the ring counter may be effectively lengthened to any multiple of ten to allow for more direct memory access intervals in one repetitive sequence. One device is a network bus adapter which serially shifts onto the command and data bus, a data word (8 bits plus control and parity bits) during the next ten direct memory access intervals after it has been granted access. The NBA is therefore allocated only one access in every ten intervals, which is a predetermined interval for all centers. The ring counters of all centers are periodically synchronized by DMA SYNC signal to assure that all NBAs be able to function in synchronism for data transfer from one center to another.

Implementation of neuromorphic systems: from discrete components to analog VLSI chips (testing and communication issues).

PubMed

Dante, V; Del Giudice, P; Mattia, M

2001-01-01

We review a series of implementations of electronic devices aiming at imitating to some extent structure and function of simple neural systems, with particular emphasis on communication issues. We first provide a short overview of general features of such "neuromorphic" devices and the implications of setting up "tests" for them. We then review the developments directly related to our work at the Istituto Superiore di Sanità (ISS): a pilot electronic neural network implementing a simple classifier, autonomously developing internal representations of incoming stimuli; an output network, collecting information from the previous classifier and extracting the relevant part to be forwarded to the observer; an analog, VLSI (very large scale integration) neural chip implementing a recurrent network of spiking neurons and plastic synapses, and the test setup for it; a board designed to interface the standard PCI (peripheral component interconnect) bus of a PC with a special purpose, asynchronous bus for communication among neuromorphic chips; a short and preliminary account of an application-oriented device, taking advantage of the above communication infrastructure.

Effects of the window openings on the micro-environmental condition in a school bus

NASA Astrophysics Data System (ADS)

Li, Fei; Lee, Eon S.; Zhou, Bin; Liu, Junjie; Zhu, Yifang

2017-10-01

School bus is an important micro-environment for children's health because the level of in-cabin air pollution can increase due to its own exhaust in addition to on-road traffic emissions. However, it has been challenging to understand the in-cabin air quality that is associated with complex airflow patterns inside and outside a school bus. This study conducted Computational Fluid Dynamics (CFD) modeling analyses to determine the effects of window openings on the self-pollution for a school bus. Infiltration through the window gaps is modeled by applying variable numbers of active computational cells as a function of the effective area ratio of the opening. The experimental data on ventilation rates from the literature was used to validate the model. Ultrafine particles (UFPs) and black carbon (BC) concentrations were monitored in ;real world; field campaigns using school buses. This modeling study examined the airflow pattern inside the school bus under four different types of side-window openings at 20, 40, and 60 mph (i.e., a total of 12 cases). We found that opening the driver's window could allow the infiltration of exhaust through window/door gaps in the back of school bus; whereas, opening windows in the middle of the school bus could mitigate this phenomenon. We also found that an increased driving speed (from 20 mph to 60 mph) could result in a higher ventilation rate (up to 3.4 times) and lower mean age of air (down to 0.29 time) inside the bus.

Analysis of local bus markets : volume II – rider characteristics : final report.

DOT National Transportation Integrated Search

2017-07-04

Despite having an extensive network of public transit, traffic congestion and transportation-related greenhouse gas (GHG) emissions are significant concerns in New Jersey. This research hypothesizes that traffic congestion and air quality concerns in...

Analysis of local bus markets : volume I – methodology and findings : final report.

DOT National Transportation Integrated Search

2017-07-04

Despite having an extensive network of public transit, traffic congestion and transportation-related greenhouse gas (GHG) emissions are significant concerns in New Jersey. This research hypothesizes that traffic congestion and air quality concerns in...

Analysis of local bus markets : volume III – travel characteristics : final report.

DOT National Transportation Integrated Search

2017-07-04

Despite having an extensive network of public transit, traffic congestion and transportation-related greenhouse gas (GHG) emissions are significant concerns in New Jersey. This research hypothesizes that traffic congestion and air quality concerns in...

Analysis of local bus markets – volumes I - III: technical brief.

DOT National Transportation Integrated Search

2017-07-04

Despite having an extensive network of public transit, traffic congestion and transportation-related greenhouse gas (GHG) emissions are significant concerns in New Jersey. This research examines the congestion and GHG impacts of transit by exclusivel...

MOBS - A modular on-board switching system

NASA Astrophysics Data System (ADS)

Berner, W.; Grassmann, W.; Piontek, M.

The authors describe a multibeam satellite system that is designed for business services and for communications at a high bit rate. The repeater is regenerative with a modular onboard switching system. It acts not only as baseband switch but also as the central node of the network, performing network control and protocol evaluation. The hardware is based on a modular bus/memory architecture with associated processors.

A preliminary survey analysis of school shuttle bus system towards smart mobility solutions

NASA Astrophysics Data System (ADS)

Yue, Wong Seng; Hoy, Cheong Wan; Chye, Koh Keng

2017-10-01

Mobility and accessibility are crucial indicators of urban development. Public transport in the urban areas came into existence to fulfil transportation needs as well as mobility and accessibility demands. Ridership can be affected by the quality and quantity of transit service. However, technical improvements are needed for such as real-time bus information, controlling run time and headway delay. Thus, this paper is aimed to carry out a preliminary survey to determine the problems of school shuttle bus that faced by the students in a selected educational institution, their perceptions of using shuttle bus tracking and information mobile application and impacts of real-time information of public transits on bus ridership and towards smart mobility solutions. Efficient public transportation system needs further investigation about the role of mobile application for the bus tracking system in supporting smart mobility actions and real-time information. The proposed application also provides a smart solution for the management of public infrastructures and urban facilities in Malaysia in future. Eventually, this study opens an opportunity to improve Malaysian quality of life on the public value that created for the city as a whole.

A modular neural network scheme applied to fault diagnosis in electric power systems.

PubMed

Flores, Agustín; Quiles, Eduardo; García, Emilio; Morant, Francisco; Correcher, Antonio

2014-01-01

This work proposes a new method for fault diagnosis in electric power systems based on neural modules. With this method the diagnosis is performed by assigning a neural module for each type of component comprising the electric power system, whether it is a transmission line, bus or transformer. The neural modules for buses and transformers comprise two diagnostic levels which take into consideration the logic states of switches and relays, both internal and back-up, with the exception of the neural module for transmission lines which also has a third diagnostic level which takes into account the oscillograms of fault voltages and currents as well as the frequency spectrums of these oscillograms, in order to verify if the transmission line had in fact been subjected to a fault. One important advantage of the diagnostic system proposed is that its implementation does not require the use of a network configurator for the system; it does not depend on the size of the power network nor does it require retraining of the neural modules if the power network increases in size, making its application possible to only one component, a specific area, or the whole context of the power system.

A Modular Neural Network Scheme Applied to Fault Diagnosis in Electric Power Systems

PubMed Central

Flores, Agustín; Morant, Francisco

2014-01-01

This work proposes a new method for fault diagnosis in electric power systems based on neural modules. With this method the diagnosis is performed by assigning a neural module for each type of component comprising the electric power system, whether it is a transmission line, bus or transformer. The neural modules for buses and transformers comprise two diagnostic levels which take into consideration the logic states of switches and relays, both internal and back-up, with the exception of the neural module for transmission lines which also has a third diagnostic level which takes into account the oscillograms of fault voltages and currents as well as the frequency spectrums of these oscillograms, in order to verify if the transmission line had in fact been subjected to a fault. One important advantage of the diagnostic system proposed is that its implementation does not require the use of a network configurator for the system; it does not depend on the size of the power network nor does it require retraining of the neural modules if the power network increases in size, making its application possible to only one component, a specific area, or the whole context of the power system. PMID:25610897

Concurrent communication among multi-transceiver stations over shared media. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Birk, Yitzhak

1987-01-01

In order to increase a local-area network's throughput beyond a single bus data rate without using dedicated switching nodes, multiple buses and multitransceiver stations are required. The design space of single-hop interconnections is explored among such stations. Interconnections are presented whose throughput can grow quadratically with the number of transmitters and receivers per station. These are referred to as selective broadcast interconnections (SBIs). The performance of various SBIs are studied. A spread-spectrum channel can accommodate several current successful transmission, and a single-transceiver node can thus utilize only a small fraction of the channel capacity. In order to allocate the appropriate fraction of capacity to a busy node, it is proposed to equip it with several transmitters and receivers, thereby turning it into a supernode. Several architectures and operation policies for supernodes are suggested and compared. It is shown that a supernode can significantly outperform a collection of independent conventional nodes with the same total numbers of transmitters and receivers. Packet-radio networks with half-duplex nodes, as well as networks with full-duplex nodes, are considered.

ITS National Intelligent Transportation Systems Program Plan: Five Year Horizon Plan

DOT National Transportation Integrated Search

2000-08-01

Transportation is vital to the social and economic health of the nation. Surface transportation systems - the net-works of highways, local streets, bus routes, and rail lines - are the ties that bind communities and facilitate commerce, connecting re...

Communications systems and methods for subsea processors

DOEpatents

Gutierrez, Jose; Pereira, Luis

2016-04-26

A subsea processor may be located near the seabed of a drilling site and used to coordinate operations of underwater drilling components. The subsea processor may be enclosed in a single interchangeable unit that fits a receptor on an underwater drilling component, such as a blow-out preventer (BOP). The subsea processor may issue commands to control the BOP and receive measurements from sensors located throughout the BOP. A shared communications bus may interconnect the subsea processor and underwater components and the subsea processor and a surface or onshore network. The shared communications bus may be operated according to a time division multiple access (TDMA) scheme.

Stormwater Pollutant Control from Critical Source Areas

EPA Science Inventory

Critical source areas include: vehicular maintenance facilities, parking lots and bus terminals, junk and lumber yards, industrial storage facilities, loading docks and refueling areas, manufacturing sites, etc. Addressing pollutant runoff from these areas is an important compon...

Computer hardware for radiologists: Part 2.

PubMed

Indrajit, Ik; Alam, A

2010-11-01

Computers are an integral part of modern radiology equipment. In the first half of this two-part article, we dwelt upon some fundamental concepts regarding computer hardware, covering components like motherboard, central processing unit (CPU), chipset, random access memory (RAM), and memory modules. In this article, we describe the remaining computer hardware components that are of relevance to radiology. "Storage drive" is a term describing a "memory" hardware used to store data for later retrieval. Commonly used storage drives are hard drives, floppy drives, optical drives, flash drives, and network drives. The capacity of a hard drive is dependent on many factors, including the number of disk sides, number of tracks per side, number of sectors on each track, and the amount of data that can be stored in each sector. "Drive interfaces" connect hard drives and optical drives to a computer. The connections of such drives require both a power cable and a data cable. The four most popular "input/output devices" used commonly with computers are the printer, monitor, mouse, and keyboard. The "bus" is a built-in electronic signal pathway in the motherboard to permit efficient and uninterrupted data transfer. A motherboard can have several buses, including the system bus, the PCI express bus, the PCI bus, the AGP bus, and the (outdated) ISA bus. "Ports" are the location at which external devices are connected to a computer motherboard. All commonly used peripheral devices, such as printers, scanners, and portable drives, need ports. A working knowledge of computers is necessary for the radiologist if the workflow is to realize its full potential and, besides, this knowledge will prepare the radiologist for the coming innovations in the 'ever increasing' digital future.

Distributed Generation Planning using Peer Enhanced Multi-objective Teaching-Learning based Optimization in Distribution Networks

NASA Astrophysics Data System (ADS)

Selvam, Kayalvizhi; Vinod Kumar, D. M.; Siripuram, Ramakanth

2017-04-01

In this paper, an optimization technique called peer enhanced teaching learning based optimization (PeTLBO) algorithm is used in multi-objective problem domain. The PeTLBO algorithm is parameter less so it reduced the computational burden. The proposed peer enhanced multi-objective based TLBO (PeMOTLBO) algorithm has been utilized to find a set of non-dominated optimal solutions [distributed generation (DG) location and sizing in distribution network]. The objectives considered are: real power loss and the voltage deviation subjected to voltage limits and maximum penetration level of DG in distribution network. Since the DG considered is capable of injecting real and reactive power to the distribution network the power factor is considered as 0.85 lead. The proposed peer enhanced multi-objective optimization technique provides different trade-off solutions in order to find the best compromise solution a fuzzy set theory approach has been used. The effectiveness of this proposed PeMOTLBO is tested on IEEE 33-bus and Indian 85-bus distribution system. The performance is validated with Pareto fronts and two performance metrics (C-metric and S-metric) by comparing with robust multi-objective technique called non-dominated sorting genetic algorithm-II and also with the basic TLBO.

Evolution of weighted complex bus transit networks with flow

NASA Astrophysics Data System (ADS)

Huang, Ailing; Xiong, Jie; Shen, Jinsheng; Guan, Wei

2016-02-01

Study on the intrinsic properties and evolutional mechanism of urban public transit networks (PTNs) has great significance for transit planning and control, particularly considering passengers’ dynamic behaviors. This paper presents an empirical analysis for exploring the complex properties of Beijing’s weighted bus transit network (BTN) based on passenger flow in L-space, and proposes a bi-level evolution model to simulate the development of transit routes from the view of complex network. The model is an iterative process that is driven by passengers’ travel demands and dual-controlled interest mechanism, which is composed of passengers’ spatio-temporal requirements and cost constraint of transit agencies. Also, the flow’s dynamic behaviors, including the evolutions of travel demand, sectional flow attracted by a new link and flow perturbation triggered in nearby routes, are taken into consideration in the evolutional process. We present the numerical experiment to validate the model, where the main parameters are estimated by using distribution functions that are deduced from real-world data. The results obtained have proven that our model can generate a BTN with complex properties, such as the scale-free behavior or small-world phenomenon, which shows an agreement with our empirical results. Our study’s results can be exploited to optimize the real BTN’s structure and improve the network’s robustness.

Plug-and-Play Environmental Monitoring Spacecraft Subsystem

NASA Technical Reports Server (NTRS)

Patel, Jagdish; Brinza, David E.; Tran, Tuan A.; Blaes, Brent R.

2011-01-01

A Space Environment Monitor (SEM) subsystem architecture has been developed and demonstrated that can benefit future spacecraft by providing (1) real-time knowledge of the spacecraft state in terms of exposure to the environment; (2) critical, instantaneous information for anomaly resolution; and (3) invaluable environmental data for designing future missions. The SEM architecture consists of a network of plug-and- play (PnP) Sensor Interface Units (SIUs), each servicing one or more environmental sensors. The SEM architecture is influenced by the IEEE Smart Transducer Interface Bus standard (IEEE Std 1451) for its PnP functionality. A network of PnP Spacecraft SIUs is enabling technology for gathering continuous real-time information critical to validating spacecraft health in harsh space environments. The demonstrated system that provided a proof-of-concept of the SEM architecture consisted of three SIUs for measurement of total ionizing dose (TID) and single event upset (SEU) radiation effects, electromagnetic interference (EMI), and deep dielectric charging through use of a prototype Internal Electro-Static Discharge Monitor (IESDM). Each SIU consists of two stacked 2X2 in. (approximately 5X5 cm) circuit boards: a Bus Interface Unit (BIU) board that provides data conversion, processing and connection to the SEM power-and-data bus, and a Sensor Interface Electronics (SIE) board that provides sensor interface needs and data path connection to the BIU.

Intelligent transportation systems field operational test cross-cutting study : emergency notification and response

DOT National Transportation Integrated Search

2000-08-01

Transportation is vital to the social and economic health of the nation. Surface transportation systems ? the networks of highways, local streets, bus routes, and rail lines ? are the ties that bind communities and facilitate commerce. Despite the fa...

Design of temperature detection device for drum of belt conveyor

NASA Astrophysics Data System (ADS)

Zhang, Li; He, Rongjun

2018-03-01

For difficult wiring and big measuring error existed in the traditional temperature detection method for drum of belt conveyor, a temperature detection device for drum of belt conveyor based on Radio Frequency(RF) communication is designed. In the device, detection terminal can collect temperature data through tire pressure sensor chip SP370 which integrates temperature detection and RF emission. The receiving terminal which is composed of RF receiver chip and microcontroller receives the temperature data and sends it to Controller Area Network(CAN) bus. The test results show that the device meets requirements of field application with measuring error ±3.73 ° and single button battery can provide continuous current for the detection terminal over 1.5 years.

Exposure to diesel exhaust fumes in the context of exposure to ultrafine particles.

PubMed

Bujak-Pietrek, Stella; Mikołajczyk, Urszula; Kamińska, Irena; Cieślak, Małgorzata; Szadkowska-Stańczyk, Irena

2016-01-01

Diesel exhaust fumes emission is a significant source of ultrafine particles, the size of which is expressed in nanometers. People occupationally exposed to diesel exhaust particles include mainly workers servicing vehicles with engines of this type. This article presents the analysis of measurements of ultrafine particle concentrations occurring in the bus depot premises during the work connected with everyday technical servicing of buses. The measurements were carried out in the everyday servicing (ES) room of the bus depot before, during and after the work connected with bus servicing. Determinations included: particle concentrations in terms of particle number and particle surface area, and mass concentrations of aerosol. Mean value of number concentration of 10- to 1000-nm particles increased almost 20-fold, from 7600 particles/cm3 before starting bus servicing procedures to 130 000 particles/cm3 during the bus servicing procedures in the room. During the procedures, the mean surface area concentration of particles potentially deposited in the alveolar (A) region was almost 3 times higher than that of the particles depositing in the tracheo-bronchial (TB) region: 356.46 μm2/cm3 vs. 95.97 μm2/cm3, respectively. The mass concentration of the fraction of particulate matter with aerodynamic diameter 0.02-1 μm (PM1) increased 5-fold during the analyzed procedures and was 0.042 mg/m3 before, and 0.298 mg/m3 while the procedures continued. At the time when bus servicing procedures continued in the ES room, a very high increase in all parameters of the analyzed particles was observed. The diesel exhaust particles exhibit a very high degree of fragmentation and, while their number is very high and their surface area is very large, their mass concentration is relatively low. The above findings confirm that ultrafine particles found in diesel exhaust fumes may be harmful to the health of the exposed people, and to their respiratory tract in particular. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Large area organic light emitting diodes with multilayered graphene anodes

NASA Astrophysics Data System (ADS)

Moon, Jaehyun; Hwang, Joohyun; Choi, Hong Kyw; Kim, Taek Yong; Choi, Sung-Yool; Joo, Chul Woong; Han, Jun-Han; Shin, Jin-Wook; Lee, Bong Joon; Cho, Doo-Hee; Huh, Jin Woo; Park, Seung Koo; Cho, Nam Sung; Chu, Hye Yong; Lee, Jeong-Ik

2012-09-01

In this work, we demonstrate fully uniform blue fluorescence graphene anode OLEDs, which have an emission area of 10×7 mm2. Catalytically grown multilayered graphene films have been used as the anode material. In order to compensate the current drop, which is due to the graphene's electrical resistance, we have furnished metal bus lines on the support. Processing and optical issues involved in graphene anode OLED fabrications are presented. The fabricated OLEDs with graphene anode showed comparable performances to that of ITO anode OLEDs. Our works shows that metal bus furnished graphene anode can be extended into large area OLED lighting applications in which flexibility and transparency is required.

Analysis and Application of Microgrids

NASA Astrophysics Data System (ADS)

Yue, Lu

New trends of generating electricity locally and utilizing non-conventional or renewable energy sources have attracted increasing interests due to the gradual depletion of conventional fossil fuel energy sources. The new type of power generation is called Distributed Generation (DG) and the energy sources utilized by Distributed Generation are termed Distributed Energy Sources (DERs). With DGs embedded in the distribution networks, they evolve from passive distribution networks to active distribution networks enabling bidirectional power flows in the networks. Further incorporating flexible and intelligent controllers and employing future technologies, active distribution networks will turn to a Microgrid. A Microgrid is a small-scale, low voltage Combined with Heat and Power (CHP) supply network designed to supply electrical and heat loads for a small community. To further implement Microgrids, a sophisticated Microgrid Management System must be integrated. However, due to the fact that a Microgrid has multiple DERs integrated and is likely to be deregulated, the ability to perform real-time OPF and economic dispatch with fast speed advanced communication network is necessary. In this thesis, first, problems such as, power system modelling, power flow solving and power system optimization, are studied. Then, Distributed Generation and Microgrid are studied and reviewed, including a comprehensive review over current distributed generation technologies and Microgrid Management Systems, etc. Finally, a computer-based AC optimization method which minimizes the total transmission loss and generation cost of a Microgrid is proposed and a wireless communication scheme based on synchronized Code Division Multiple Access (sCDMA) is proposed. The algorithm is tested with a 6-bus power system and a 9-bus power system.

Synthesis of highly integrated optical network based on microdisk-resonator add-drop filters in silicon-on-insulator technology

NASA Astrophysics Data System (ADS)

Kaźmierczak, Andrzej; Dortu, Fabian; Giannone, Domenico; Bogaerts, Wim; Drouard, Emmanuel; Rojo-Romeo, Pedro; Gaffiot, Frederic

2009-10-01

We analyze a highly compact optical add-drop filter topology based on a pair of microdisk resonators and a bus waveguide intersection. The filter is further assessed on an integrated optical 4×4 network for optical on-chip communication. The proposed network structure, as compact as 50×50 μm, is fabricated in a CMOS-compatible process on a silicon-on-insulator (SOI) substrate. Finally, the experimental results demonstrate the proper operation of the fabricated devices.

IEEE-1588(Trademark) Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems

DTIC Science & Technology

2002-12-01

34th Annual Precise Time and Time Interval (PTTI) Meeting 243 IEEE-1588™ STANDARD FOR A PRECISION CLOCK SYNCHRONIZATION PROTOCOL FOR... synchronization . 2. Cyclic-systems. In cyclic-systems, timing is periodic and is usually defined by the characteristics of a cyclic network or bus...incommensurate, timing schedules for each device are easily implemented. In addition, synchronization accuracy depends on the accuracy of the common

Comparison of the application of B-mode and strain elastography ultrasound in the estimation of lymph node metastasis of papillary thyroid carcinoma based on a radiomics approach.

PubMed

Liu, Tongtong; Ge, Xifeng; Yu, Jinhua; Guo, Yi; Wang, Yuanyuan; Wang, Wenping; Cui, Ligang

2018-06-21

B-mode ultrasound (B-US) and strain elastography ultrasound (SE-US) images have a potential to distinguish thyroid tumor with different lymph node (LN) status. The purpose of our study is to investigate whether the application of multi-modality images including B-US and SE-US can improve the discriminability of thyroid tumor with LN metastasis based on a radiomics approach. Ultrasound (US) images including B-US and SE-US images of 75 papillary thyroid carcinoma (PTC) cases were retrospectively collected. A radiomics approach was developed in this study to estimate LNs status of PTC patients. The approach included image segmentation, quantitative feature extraction, feature selection and classification. Three feature sets were extracted from B-US, SE-US, and multi-modality containing B-US and SE-US. They were used to evaluate the contribution of different modalities. A total of 684 radiomics features have been extracted in our study. We used sparse representation coefficient-based feature selection method with 10-bootstrap to reduce the dimension of feature sets. Support vector machine with leave-one-out cross-validation was used to build the model for estimating LN status. Using features extracted from both B-US and SE-US, the radiomics-based model produced an area under the receiver operating characteristic curve (AUC) [Formula: see text] 0.90, accuracy (ACC) [Formula: see text] 0.85, sensitivity (SENS) [Formula: see text] 0.77 and specificity (SPEC) [Formula: see text] 0.88, which was better than using features extracted from B-US or SE-US separately. Multi-modality images provided more information in radiomics study. Combining use of B-US and SE-US could improve the LN metastasis estimation accuracy for PTC patients.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansen, Timothy M.; Palmintier, Bryan; Suryanarayanan, Siddharth

As more Smart Grid technologies (e.g., distributed photovoltaic, spatially distributed electric vehicle charging) are integrated into distribution grids, static distribution simulations are no longer sufficient for performing modeling and analysis. GridLAB-D is an agent-based distribution system simulation environment that allows fine-grained end-user models, including geospatial and network topology detail. A problem exists in that, without outside intervention, once the GridLAB-D simulation begins execution, it will run to completion without allowing the real-time interaction of Smart Grid controls, such as home energy management systems and aggregator control. We address this lack of runtime interaction by designing a flexible communication interface, Bus.pymore » (pronounced bus-dot-pie), that uses Python to pass messages between one or more GridLAB-D instances and a Smart Grid simulator. This work describes the design and implementation of Bus.py, discusses its usefulness in terms of some Smart Grid scenarios, and provides an example of an aggregator-based residential demand response system interacting with GridLAB-D through Bus.py. The small scale example demonstrates the validity of the interface and shows that an aggregator using said interface is able to control residential loads in GridLAB-D during runtime to cause a reduction in the peak load on the distribution system in (a) peak reduction and (b) time-of-use pricing cases.« less

Planning Tripoli Metro Network by the Use of Remote Sensing Imagery

NASA Astrophysics Data System (ADS)

Alhusain, O.; Engedy, Gy.; Milady, A.; Paulini, L.; Soos, G.

2012-08-01

Tripoli, the capital city of Libya is going through significant and integrated development process, this development is expected to continue in the next few decades. The Libyan authorities have put it as their goal to develop Tripoli to an important metropolis in North Africa. To achieve this goal, they identified goals for the city's future development in all human, economic, cultural, touristic, and nonetheless infrastructure levels. On the infrastructure development level, among other things, they have identified the development of public transportation as one of the important development priorities. At present, public transportation in Tripoli is carried out by a limited capacity bus network alongside of individual transportation. However, movement in the city is characterized mainly by individual transportation with all its disadvantages such as traffic jams, significant air pollution with both carbon monoxide and dust, and lack of parking space. The Libyan authorities wisely opted for an efficient, modern, and environment friendly solution for public transportation, this was to plan a complex Metro Network as the backbone of public transportation in the city, and to develop and integrate the bus network and other means of transportation to be in harmony with the planned Metro network. The Metro network is planned to provide convenient connections to Tripoli International Airport and to the planned Railway station. They plan to build a system of Park and Ride (P+R) facilities at suitable locations along the Metro lines. This paper will present in details the planned Metro Network, some of the applied technological solutions, the importance of applying remote sensing and GIS technologies in different planning phases, and problems and benefits associated with the use of multi-temporal-, multi-format spatial data in the whole network planning phase.

Training Manual for School Bus Drivers Transporting the Handicapped. [A Resource Manual for the Development and Evaluation of Special Programs for Exceptional Students, Volume IV-A].

ERIC Educational Resources Information Center

Florida State Dept. of Education, Tallahassee. Bureau of Education for Exceptional Students.

One of a series designed to help Florida school districts provide special programs for exceptional children, the training packet is intended to be used in a 2-day training session for school bus drivers who transport handicapped students. The manual includes a brief introduction to five disability areas (physical impairments, visual impairments,…

Structural and robustness properties of smart-city transportation networks

NASA Astrophysics Data System (ADS)

Zhang, Zhen-Gang; Ding, Zhuo; Fan, Jing-Fang; Meng, Jun; Ding, Yi-Min; Ye, Fang-Fu; Chen, Xiao-Song

2015-09-01

The concept of smart city gives an excellent resolution to construct and develop modern cities, and also demands infrastructure construction. How to build a safe, stable, and highly efficient public transportation system becomes an important topic in the process of city construction. In this work, we study the structural and robustness properties of transportation networks and their sub-networks. We introduce a complementary network model to study the relevance and complementarity between bus network and subway network. Our numerical results show that the mutual supplement of networks can improve the network robustness. This conclusion provides a theoretical basis for the construction of public traffic networks, and it also supports reasonable operation of managing smart cities. Project supported by the Major Projects of the China National Social Science Fund (Grant No. 11 & ZD154).

Particles exposure while sitting at bus stops of hot and humid Singapore

NASA Astrophysics Data System (ADS)

Velasco, Erik; Tan, Sok Huang

2016-10-01

Transport microenvironments represent hotspots of personal exposure to airborne toxics, particularly of ultrafine particles. Thus, a large exposure may be experienced during daily commuting trips. Amongst these microenvironments, bus stops are critical because of the commuters' close proximity to fresh fumes rich in particles emitted by passing, idling and accelerating buses and motor vehicles, in general. Standing at a bus stop may represent a period of disproportionately high exposure and it is, therefore, essential to know the number, chemical composition and physical characteristics of such particles for a proper public health assessment and design of mobility strategies. On this account, a set of portable and battery operated sensors were used to evaluate a number of properties of the traffic particles to which thousands of citizens are daily exposed at bus stops of Singapore. In terms of fine particles, the exposure concentration was on average 1.5-3 times higher than the mean concentration at ambient level reported by the local authorities. On average 60% of those particles corresponded to black carbon. An important presence of particle-bound polycyclic aromatics was observed. The particle number concentration and active surface area were effective metrics to quantify ultrafine particles, as expected both showed strong correlations. The number of particles at bus stops was on average 3.5 times higher than at ambient level. The most alarming issue was probably the size of the particles. Assuming spherical particles, a median of 27 nm was estimated based on the active surface area and particle number data. Particles of this size form the nucleation mode, which is related to harmful health effects.

Integrated Services Digital Network

DTIC Science & Technology

1992-01-01

users. " Pair Gain • ISDN’s capability to deliver multiple communications channels over a limited set of wires (as in 2B+D service or pasive bus...configuration commands to devices encountered in a communications path, is not yet a reality at Redstone. But for that matter , transparent connectivity

The Status of Spacecraft Bus and Platform Technology Development under the NASA ISPT Program

NASA Technical Reports Server (NTRS)

Anderson, David J.; Munk, Michelle M.; Pencil, Eric; Dankanich, John; Glaab, Louis; Peterson, Todd

2013-01-01

The In-Space Propulsion Technology (ISPT) program is developing spacecraft bus and platform technologies that will enable or enhance NASA robotic science missions. The ISPT program is currently developing technology in four areas that include Propulsion System Technologies (electric and chemical), Entry Vehicle Technologies (aerocapture and Earth entry vehicles), Spacecraft Bus and Sample Return Propulsion Technologies (components and ascent vehicles), and Systems/Mission Analysis. Three technologies are ready for near-term flight infusion: 1) the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance; 2) NASA s Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system; and 3) Aerocapture technology development with investments in a family of thermal protection system (TPS) materials and structures; guidance, navigation, and control (GN&C) models of blunt-body rigid aeroshells; and aerothermal effect models. Two component technologies being developed with flight infusion in mind are the Advanced Xenon Flow Control System and ultralightweight propellant tank technologies. Future directions for ISPT are technologies that relate to sample return missions and other spacecraft bus technology needs like: 1) Mars Ascent Vehicles (MAV); 2) multi-mission technologies for Earth Entry Vehicles (MMEEV); and 3) electric propulsion. These technologies are more vehicles and mission-focused, and present a different set of technology development and infusion steps beyond those previously implemented. The Systems/Mission Analysis area is focused on developing tools and assessing the application of propulsion and spacecraft bus technologies to a wide variety of mission concepts. These inspace propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, and sample return missions currently under consideration, as well as having broad applicability to potential Flagship missions. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness of in-space propulsion technologies in the areas of electric propulsion, Aerocapture, Earth entry vehicles, propulsion components, Mars ascent vehicle, and mission/systems analysis.

The status of spacecraft bus and platform technology development under the NASA ISPT program

NASA Astrophysics Data System (ADS)

Anderson, D. J.; Munk, M. M.; Pencil, E.; Dankanich, J.; Glaab, L.; Peterson, T.

The In-Space Propulsion Technology (ISPT) program is developing spacecraft bus and platform technologies that will enable or enhance NASA robotic science missions. The ISPT program is currently developing technology in four areas that include Propulsion System Technologies (electric and chemical), Entry Vehicle Technologies (aerocapture and Earth entry vehicles), Spacecraft Bus and Sample Return Propulsion Technologies (components and ascent vehicles), and Systems/Mission Analysis. Three technologies are ready for near-term flight infusion: 1) the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance; 2) NASA's Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system; and 3) Aerocapture technology development with investments in a family of thermal protection system (TPS) materials and structures; guidance, navigation, and control (GN& C) models of blunt-body rigid aeroshells; and aerothermal effect models. Two component technologies being developed with flight infusion in mind are the Advanced Xenon Flow Control System and ultra-lightweight propellant tank technologies. Future directions for ISPT are technologies that relate to sample return missions and other spacecraft bus technology needs like: 1) Mars Ascent Vehicles (MAV); 2) multi-mission technologies for Earth Entry Vehicles (MMEEV); and 3) electric propulsion. These technologies are more vehicles and mission-focused, and present a different set of technology development and infusion steps beyond those previously implemented. The Systems/Mission Analysis area is focused on developing tools and assessing the application of propulsion and spacecraft bus technologies to a wide variety of mission concepts. These in-space propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, and sample return missions currently under consideration, as well as having broad applicabilit- to potential Flagship missions. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness of in-space propulsion technologies in the areas of electric propulsion, Aerocapture, Earth entry vehicles, propulsion components, Mars ascent vehicle, and mission/systems analysis.

The Status of Spacecraft Bus and Platform Technology Development Under the NASA ISPT Program

NASA Technical Reports Server (NTRS)

Anderson, David J.; Munk, Michelle M.; Pencil, Eric J.; Dankanich, John; Glaab, Louis J.

2013-01-01

The In-Space Propulsion Technology (ISPT) program is developing spacecraft bus and platform technologies that will enable or enhance NASA robotic science missions. The ISPT program is currently developing technology in four areas that include Propulsion System Technologies (electric and chemical), Entry Vehicle Technologies (aerocapture and Earth entry vehicles), Spacecraft Bus and Sample Return Propulsion Technologies (components and ascent vehicles), and Systems/Mission Analysis. Three technologies are ready for near-term flight infusion: 1) the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance 2) NASAs Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system and 3) Aerocapture technology development with investments in a family of thermal protection system (TPS) materials and structures guidance, navigation, and control (GN&C) models of blunt-body rigid aeroshells and aerothermal effect models. Two component technologies being developed with flight infusion in mind are the Advanced Xenon Flow Control System, and ultra-lightweight propellant tank technologies. Future direction for ISPT are technologies that relate to sample return missions and other spacecraft bus technology needs like: 1) Mars Ascent Vehicles (MAV) 2) multi-mission technologies for Earth Entry Vehicles (MMEEV) and 3) electric propulsion. These technologies are more vehicle and mission-focused, and present a different set of technology development and infusion steps beyond those previously implemented. The Systems/Mission Analysis area is focused on developing tools and assessing the application of propulsion and spacecraft bus technologies to a wide variety of mission concepts. These in-space propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, and sample return missions currently under consideration, as well as having broad applicability to potential Flagship missions. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness of in-space propulsion technologies in the areas of electric propulsion, Aerocapture, Earth entry vehicles, propulsion components, Mars ascent vehicle, and mission/systems analysis.

Myocardial infarction among male bus, taxi, and lorry drivers in middle Sweden.

PubMed Central

Gustavsson, P; Alfredsson, L; Brunnberg, H; Hammar, N; Jakobsson, R; Reuterwall, C; Ostlin, P

1996-01-01

OBJECTIVES: The aim of the present case-referent study was to investigate the incidence of myocardial infarction among male professional drivers, taking the type of vehicles and area of residence into account. METHODS: The study base comprised all men aged 30-74 in five counties in middle Sweden during 1976-81 or 1976-84. Incident cases of the first episode of myocardial infarction were identified from registers of hospital admissions and causes of deaths. Referents were selected randomly from the study base. Information about occupation was obtained from the national censuses in 1970 and 1975. The possible impact from tobacco smoking and overweight were evaluated by simulations in combination with indirect data on these factors. RESULTS: The incidence of myocardial infarction was increased among bus drivers in Stockholm (relative risk (RR) = 1.53, 95% confidence interval (95% CI) 1.15-2.05), and among taxi drivers both in Stockholm (RR 1.65, 95% CI 1.30-2.11) and in the surrounding rural counties (RR 1.82, 95% CI 1.17-2.82). A smaller increase was found among long distance lorry drivers, whereas the relative risk among short distance lorry drivers was close to unity. Indirect comparisons make it unlikely that the excess among bus drivers in Stockholm could be explained by uncontrolled confounding from tobacco smoking or overweight. A very high proportion (more than 80%) of urban bus drivers in Sweden report a combination of high psychological demands and low control at work. CONCLUSIONS: Different types of drivers are at different risk of myocardial infarction. Bus drivers in urban areas seem to be at an increased risk, which is unlikely to be explained by uncontrolled confounding from tobacco smoking or overweight. Psychosocial work conditions may play a part in the increased incidence of myocardial infarction among urban bus drivers and should be investigated further. PMID:8664960

Analysis of critical operating conditions for LV distribution networks with microgrids

NASA Astrophysics Data System (ADS)

Zehir, M. A.; Batman, A.; Sonmez, M. A.; Font, A.; Tsiamitros, D.; Stimoniaris, D.; Kollatou, T.; Bagriyanik, M.; Ozdemir, A.; Dialynas, E.

2016-11-01

Increase in the penetration of Distributed Generation (DG) in distribution networks, raises the risk of voltage limit violations while contributing to line losses. Especially in low voltage (LV) distribution networks (secondary distribution networks), impacts of active power flows on the bus voltages and on the network losses are more dominant. As network operators must meet regulatory limitations, they have to take into account the most critical operating conditions in their systems. In this study, it is aimed to present the impact of the worst operation cases of LV distribution networks comprising microgrids. Simulation studies are performed on a field data-based virtual test-bed. The simulations are repeated for several cases consisting different microgrid points of connection with different network loading and microgrid supply/demand conditions.

Intelligent Urban Public Transportation for Accessibility Dedicated to People with Disabilities

PubMed Central

Zhou, Haiying; Hou, Kun-Mean; Zuo, Decheng; Li, Jian

2012-01-01

The traditional urban public transport system generally cannot provide an effective access service for people with disabilities, especially for disabled, wheelchair and blind (DWB) passengers. In this paper, based on advanced information & communication technologies (ICT) and green technologies (GT) concepts, a dedicated public urban transportation service access system named Mobi+ has been introduced, which facilitates the mobility of DWB passengers. The Mobi+ project consists of three subsystems: a wireless communication subsystem, which provides the data exchange and network connection services between buses and stations in the complex urban environments; the bus subsystem, which provides the DWB class detection & bus arrival notification services; and the station subsystem, which implements the urban environmental surveillance & bus auxiliary access services. The Mobi+ card that supports multi-microcontroller multi-transceiver adopts the fault-tolerant component-based hardware architecture, in which the dedicated embedded system software, i.e., operating system micro-kernel and wireless protocol, has been integrated. The dedicated Mobi+ embedded system provides the fault-tolerant resource awareness communication and scheduling mechanism to ensure the reliability in data exchange and service provision. At present, the Mobi+ system has been implemented on the buses and stations of line ‘2’ in the city of Clermont-Ferrand (France). The experiential results show that, on one hand the Mobi+ prototype system reaches the design expectations and provides an effective urban bus access service for people with disabilities; on the other hand the Mobi+ system is easily to deploy in the buses and at bus stations thanks to its low energy consumption and small form factor. PMID:23112622

Intelligent urban public transportation for accessibility dedicated to people with disabilities.

PubMed

Zhou, Haiying; Hou, Kun-Mean; Zuo, Decheng; Li, Jian

2012-01-01

The traditional urban public transport system generally cannot provide an effective access service for people with disabilities, especially for disabled, wheelchair and blind (DWB) passengers. In this paper, based on advanced information & communication technologies (ICT) and green technologies (GT) concepts, a dedicated public urban transportation service access system named Mobi+ has been introduced, which facilitates the mobility of DWB passengers. The Mobi+ project consists of three subsystems: a wireless communication subsystem, which provides the data exchange and network connection services between buses and stations in the complex urban environments; the bus subsystem, which provides the DWB class detection & bus arrival notification services; and the station subsystem, which implements the urban environmental surveillance & bus auxiliary access services. The Mobi+ card that supports multi-microcontroller multi-transceiver adopts the fault-tolerant component-based hardware architecture, in which the dedicated embedded system software, i.e., operating system micro-kernel and wireless protocol, has been integrated. The dedicated Mobi+ embedded system provides the fault-tolerant resource awareness communication and scheduling mechanism to ensure the reliability in data exchange and service provision. At present, the Mobi+ system has been implemented on the buses and stations of line '2' in the city of Clermont-Ferrand (France). The experiential results show that, on one hand the Mobi+ prototype system reaches the design expectations and provides an effective urban bus access service for people with disabilities; on the other hand the Mobi+ system is easily to deploy in the buses and at bus stations thanks to its low energy consumption and small form factor.

Hyperswitch Communication Network Computer

NASA Technical Reports Server (NTRS)

Peterson, John C.; Chow, Edward T.; Priel, Moshe; Upchurch, Edwin T.

1993-01-01

Hyperswitch Communications Network (HCN) computer is prototype multiple-processor computer being developed. Incorporates improved version of hyperswitch communication network described in "Hyperswitch Network For Hypercube Computer" (NPO-16905). Designed to support high-level software and expansion of itself. HCN computer is message-passing, multiple-instruction/multiple-data computer offering significant advantages over older single-processor and bus-based multiple-processor computers, with respect to price/performance ratio, reliability, availability, and manufacturing. Design of HCN operating-system software provides flexible computing environment accommodating both parallel and distributed processing. Also achieves balance among following competing factors; performance in processing and communications, ease of use, and tolerance of (and recovery from) faults.

Public Transport Systems in Poland: From Bialystok to Zielona Góra by Bus and Tram Using Universal Statistics of Complex Networks

NASA Astrophysics Data System (ADS)

Sienkiewicz, J.; Holyst, J. A.

2005-05-01

We have examined a topology of 21 public transport networks in Poland. Our data exhibit several universal features in considered systems when they are analyzed from the point of view of evolving networks. Depending on the assumed definition of a network topology the degree distribution can follow a power law p(k) ˜ k-γ or can be described by an exponential function p(k) ˜ exp (-α k). In the first case one observes that mean distances between two nodes are a linear function of logarithms of their degrees product.

Memory Network For Distributed Data Processors

NASA Technical Reports Server (NTRS)

Bolen, David; Jensen, Dean; Millard, ED; Robinson, Dave; Scanlon, George

1992-01-01

Universal Memory Network (UMN) is modular, digital data-communication system enabling computers with differing bus architectures to share 32-bit-wide data between locations up to 3 km apart with less than one millisecond of latency. Makes it possible to design sophisticated real-time and near-real-time data-processing systems without data-transfer "bottlenecks". This enterprise network permits transmission of volume of data equivalent to an encyclopedia each second. Facilities benefiting from Universal Memory Network include telemetry stations, simulation facilities, power-plants, and large laboratories or any facility sharing very large volumes of data. Main hub of UMN is reflection center including smaller hubs called Shared Memory Interfaces.

Commuter exposure to black carbon particles on diesel buses, on bicycles and on foot: a case study in a Brazilian city.

PubMed

Targino, Admir Créso; Rodrigues, Marcos Vinicius C; Krecl, Patricia; Cipoli, Yago Alonso; Ribeiro, João Paulo M

2018-01-01

Commuting in urban environments accounts for a large fraction of the daily dose of inhaled air pollutants, especially in countries where vehicles have old technologies or run on dirty fuels. We measured black carbon (BC) concentrations during bus, walk and bicycle commutes in a Brazilian city and found a large spatial variability across the surveyed area, with median values between 2.5 and 12.0 μg m -3 . Traffic volume on roadways (especially the number of heavy-duty diesel vehicles), self-pollution from the bus tailpipe, number of stops along the route and displacement speed were the main drivers of air pollution on the buses. BC concentrations increased abruptly at or close to traffic signals and bus stops, causing in-cabin peaks as large as 60.0 μg m -3 . BC hotspots for the walk mode coincided with the locations of bus stops and traffic signals, whilst measurements along a cycle lane located 12 m from the kerb were less affected. The median BC concentrations of the two active modes were significantly lower than the concentrations inside the bus, with a bus/walk and bus/bicycle ratios of up to 6. However, the greater inhalation rates of cyclist and pedestrians yielded larger doses (2.6 and 3.5 μg on a 1.5-km commute), suggesting that the greater physical effort during the active commute may outweigh the reduction in exposure due to the shift from passive to active transport modes.

Analyzing GAIAN Database (GaianDB) on a Tactical Network

DTIC Science & Technology

2015-11-30

we connected 3 Raspberry Pi’s running GaianDB and our augmented version of splatform to a network of 3 CSRs. The Raspberry Pi is a low power, low...based on Debian from a connected secure digital high capacity (SDHC) card or a universal serial bus (USB) device. The Raspberry Pi comes equipped with...requirements, capabilities, and cost make the Raspberry Pi a useful device for sensor experimentation. From there, we performed 3 types of benchmarks

UGV: security analysis of subsystem control network

NASA Astrophysics Data System (ADS)

Abbott-McCune, Sam; Kobezak, Philip; Tront, Joseph; Marchany, Randy; Wicks, Al

2013-05-01

Unmanned Ground vehicles (UGVs) are becoming prolific in the heterogeneous superset of robotic platforms. The sensors which provide odometry, localization, perception, and vehicle diagnostics are fused to give the robotic platform a sense of the environment it is traversing. The automotive industry CAN bus has dominated the industry due to the fault tolerance and the message structure allowing high priority messages to reach the desired node in a real time environment. UGVs are being researched and produced at an accelerated rate to preform arduous, repetitive, and dangerous missions that are associated with a military action in a protracted conflict. The technology and applications of the research will inevitably be turned into dual-use platforms to aid civil agencies in the performance of their various operations. Our motivation is security of the holistic system; however as subsystems are outsourced in the design, the overall security of the system may be diminished. We will focus on the CAN bus topology and the vulnerabilities introduced in UGVs and recognizable security vulnerabilities that are inherent in the communications architecture. We will show how data can be extracted from an add-on CAN bus that can be customized to monitor subsystems. The information can be altered or spoofed to force the vehicle to exhibit unwanted actions or render the UGV unusable for the designed mission. The military relies heavily on technology to maintain information dominance, and the security of the information introduced onto the network by UGVs must be safeguarded from vulnerabilities that can be exploited.

Lunar Reconnaissance Orbiter (LRO) Command and Data Handling Flight Electronics Subsystem

NASA Technical Reports Server (NTRS)

Nguyen, Quang; Yuknis, William; Haghani, Noosha; Pursley, Scott; Haddad, Omar

2012-01-01

A document describes a high-performance, modular, and state-of-the-art Command and Data Handling (C&DH) system developed for use on the Lunar Reconnaissance Orbiter (LRO) mission. This system implements a complete hardware C&DH subsystem in a single chassis enclosure that includes a processor card, 48 Gbytes of solid-state recorder memory, data buses including MIL-STD-1553B, custom RS-422, SpaceWire, analog collection, switched power services, and interfaces to the Ka-Band and S-Band RF communications systems. The C&DH team capitalized on extensive experience with hardware and software with PCI bus design, SpaceWire networking, Actel FPGA design, digital flight design techniques, and the use of VxWorks for the real-time operating system. The resulting hardware architecture was implemented to meet the LRO mission requirements. The C&DH comprises an enclosure, a backplane, a low-voltage power converter, a single-board computer, a communications interface board, four data storage boards, a housekeeping and digital input/output board, and an analog data acquisition board. The interfaces between the C&DH and the instruments and avionics are connected through a SpaceWire network, a MIL-STD-1553 bus, and a combination of synchronous and asynchronous serial data transfers over RS-422 and LVDS (low-voltage differential-signaling) electrical interfaces. The C&DH acts as the spacecraft data system with an instrument data manager providing all software and internal bus scheduling, ingestion of science data, distribution of commands, and performing science operations in real time.

A Tactile Sensor Network System Using a Multiple Sensor Platform with a Dedicated CMOS-LSI for Robot Applications †

PubMed Central

Shao, Chenzhong; Tanaka, Shuji; Nakayama, Takahiro; Hata, Yoshiyuki; Bartley, Travis; Muroyama, Masanori

2017-01-01

Robot tactile sensation can enhance human–robot communication in terms of safety, reliability and accuracy. The final goal of our project is to widely cover a robot body with a large number of tactile sensors, which has significant advantages such as accurate object recognition, high sensitivity and high redundancy. In this study, we developed a multi-sensor system with dedicated Complementary Metal-Oxide-Semiconductor (CMOS) Large-Scale Integration (LSI) circuit chips (referred to as “sensor platform LSI”) as a framework of a serial bus-based tactile sensor network system. The sensor platform LSI supports three types of sensors: an on-chip temperature sensor, off-chip capacitive and resistive tactile sensors, and communicates with a relay node via a bus line. The multi-sensor system was first constructed on a printed circuit board to evaluate basic functions of the sensor platform LSI, such as capacitance-to-digital and resistance-to-digital conversion. Then, two kinds of external sensors, nine sensors in total, were connected to two sensor platform LSIs, and temperature, capacitive and resistive sensing data were acquired simultaneously. Moreover, we fabricated flexible printed circuit cables to demonstrate the multi-sensor system with 15 sensor platform LSIs operating simultaneously, which showed a more realistic implementation in robots. In conclusion, the multi-sensor system with up to 15 sensor platform LSIs on a bus line supporting temperature, capacitive and resistive sensing was successfully demonstrated. PMID:29061954

A Tactile Sensor Network System Using a Multiple Sensor Platform with a Dedicated CMOS-LSI for Robot Applications.

PubMed

Shao, Chenzhong; Tanaka, Shuji; Nakayama, Takahiro; Hata, Yoshiyuki; Bartley, Travis; Nonomura, Yutaka; Muroyama, Masanori

2017-08-28

Robot tactile sensation can enhance human-robot communication in terms of safety, reliability and accuracy. The final goal of our project is to widely cover a robot body with a large number of tactile sensors, which has significant advantages such as accurate object recognition, high sensitivity and high redundancy. In this study, we developed a multi-sensor system with dedicated Complementary Metal-Oxide-Semiconductor (CMOS) Large-Scale Integration (LSI) circuit chips (referred to as "sensor platform LSI") as a framework of a serial bus-based tactile sensor network system. The sensor platform LSI supports three types of sensors: an on-chip temperature sensor, off-chip capacitive and resistive tactile sensors, and communicates with a relay node via a bus line. The multi-sensor system was first constructed on a printed circuit board to evaluate basic functions of the sensor platform LSI, such as capacitance-to-digital and resistance-to-digital conversion. Then, two kinds of external sensors, nine sensors in total, were connected to two sensor platform LSIs, and temperature, capacitive and resistive sensing data were acquired simultaneously. Moreover, we fabricated flexible printed circuit cables to demonstrate the multi-sensor system with 15 sensor platform LSIs operating simultaneously, which showed a more realistic implementation in robots. In conclusion, the multi-sensor system with up to 15 sensor platform LSIs on a bus line supporting temperature, capacitive and resistive sensing was successfully demonstrated.

Applicability of Bogota's TransMilenio BRT system to the United States : final report, May 2006.

DOT National Transportation Integrated Search

2006-05-01

Serving the city of Bogot, Colombia, TransMilenio is one of the worlds premier Bus Rapid Transit (BRT) systems. Commencing service in : December 2000, the system was carrying over one million passengers per day by early 2006 on a 40 mile network...

Advanced network planning for bus rapid transit : the "Quickway" model as a modal alternative to "Light Rail Lite"

DOT National Transportation Integrated Search

2008-02-01

Transit planning in the United States has tended toward viewing BRT as an analogue to light rail transit, with similar operating patterns. This model, referred to as Light Rail Lite, is compared to international best practices, which have often...

An operating system for future aerospace vehicle computer systems

NASA Technical Reports Server (NTRS)

Foudriat, E. C.; Berman, W. J.; Will, R. W.; Bynum, W. L.

1984-01-01

The requirements for future aerospace vehicle computer operating systems are examined in this paper. The computer architecture is assumed to be distributed with a local area network connecting the nodes. Each node is assumed to provide a specific functionality. The network provides for communication so that the overall tasks of the vehicle are accomplished. The O/S structure is based upon the concept of objects. The mechanisms for integrating node unique objects with node common objects in order to implement both the autonomy and the cooperation between nodes is developed. The requirements for time critical performance and reliability and recovery are discussed. Time critical performance impacts all parts of the distributed operating system; e.g., its structure, the functional design of its objects, the language structure, etc. Throughout the paper the tradeoffs - concurrency, language structure, object recovery, binding, file structure, communication protocol, programmer freedom, etc. - are considered to arrive at a feasible, maximum performance design. Reliability of the network system is considered. A parallel multipath bus structure is proposed for the control of delivery time for time critical messages. The architecture also supports immediate recovery for the time critical message system after a communication failure.

Transportation Matters: A Health Impact Assessment in Rural New Mexico.

PubMed

Del Rio, Michelle; Hargrove, William L; Tomaka, Joe; Korc, Marcelo

2017-06-13

This Health Impact Assessment (HIA) informed the decision of expanding public transportation services to rural, low income communities of southern Doña Ana County, New Mexico on the U.S./Mexico border. The HIA focused on impacts of access to health care services, education, and economic development opportunities. Qualitative and quantitative data were collected from surveys of community members, key informant interviews, a focus group with community health workers, and passenger surveys during an initial introduction of the transit system. Results from the survey showed that a high percentage of respondents would use the bus system to access the following: (1) 84% for health services; (2) 83% for formal and informal education opportunities; and (3) 81% for economic opportunities. Results from interviews and the focus group supported the benefits of access to services but many were concerned with the high costs of providing bus service in a rural area. We conclude that implementing the bus system would have major impacts on resident's health through improved access to: (1) health services, and fresh foods, especially for older adults; (2) education opportunities, such as community colleges, universities, and adult learning, especially for young adults; and (3) economic opportunities, especially jobs, job training, and consumer goods and services. We highlight the challenges associated with public transportation in rural areas where there are: (1) long distances to travel; (2) difficulties in scheduling to meet all needs; and (3) poor road and walking conditions for bus stops. The results are applicable to low income and fairly disconnected rural areas, where access to health, education, and economic opportunities are limited.

Transportation Matters: A Health Impact Assessment in Rural New Mexico

PubMed Central

Del Rio, Michelle; Hargrove, William L.; Tomaka, Joe; Korc, Marcelo

2017-01-01

This Health Impact Assessment (HIA) informed the decision of expanding public transportation services to rural, low income communities of southern Doña Ana County, New Mexico on the U.S./Mexico border. The HIA focused on impacts of access to health care services, education, and economic development opportunities. Qualitative and quantitative data were collected from surveys of community members, key informant interviews, a focus group with community health workers, and passenger surveys during an initial introduction of the transit system. Results from the survey showed that a high percentage of respondents would use the bus system to access the following: (1) 84% for health services; (2) 83% for formal and informal education opportunities; and (3) 81% for economic opportunities. Results from interviews and the focus group supported the benefits of access to services but many were concerned with the high costs of providing bus service in a rural area. We conclude that implementing the bus system would have major impacts on resident’s health through improved access to: (1) health services, and fresh foods, especially for older adults; (2) education opportunities, such as community colleges, universities, and adult learning, especially for young adults; and (3) economic opportunities, especially jobs, job training, and consumer goods and services. We highlight the challenges associated with public transportation in rural areas where there are: (1) long distances to travel; (2) difficulties in scheduling to meet all needs; and (3) poor road and walking conditions for bus stops. The results are applicable to low income and fairly disconnected rural areas, where access to health, education, and economic opportunities are limited. PMID:28608826

Terminals for Suburb Bus Transport in Bratislava

NASA Astrophysics Data System (ADS)

Schlosser, Tibor; Schlosser, Peter; Cápayová, Silvia; Hodáková, Dominika

2017-10-01

The main objective of this article is to describe the strategy for development of the public transport terminals in the city of Bratislava, Capital of Slovak Republic. The reason goes from the private operator Slovak Lines, who operates the suburb bus transport in the agglomeration of the city. For this operator was created a transport model, while placing emphasis on optimizing the compliance of suburban public transport with urban public transport in the city of Bratislava and evaluating the significance of the new Bus Station to be constructed at Mlynské Nivy - in a new down town centre of the city. The main issue is to ensure the best available offer of public transport (PT) to passengers in the Bratislava agglomeration. The subject of the study was oriented to specify and propose changes in the transport infrastructure and integrated public transport organisation on the area of the city in terms of the significant position of the new Mlynské Nivy Bus Station (MN BS), which is under preparation with realization in the year 2017.

Spacecraft design project multipurpose satellite bus MPS

NASA Technical Reports Server (NTRS)

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

1990-01-01

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

Research on centrality of urban transport network nodes

NASA Astrophysics Data System (ADS)

Wang, Kui; Fu, Xiufen

2017-05-01

Based on the actual data of urban transport in Guangzhou, 19,150 bus stations in Guangzhou (as of 2014) are selected as nodes. Based on the theory of complex network, the network model of Guangzhou urban transport is constructed. By analyzing the degree centrality index, betweenness centrality index and closeness centrality index of nodes in the network, the level of centrality of each node in the network is studied. From a different point of view to determine the hub node of Guangzhou urban transport network, corresponding to the city's key sites and major transfer sites. The reliability of the network is determined by the stability of some key nodes (transport hub station). The research of network node centralization can provide a theoretical basis for the rational allocation of urban transport network sites and public transport system planning.

Effects of transit bus interior configuration on performance of wheeled mobility users during simulated boarding and disembarking.

PubMed

D'Souza, Clive; Paquet, Victor; Lenker, James A; Steinfeld, Edward

2017-07-01

The emergence of low-floor bus designs and related regulatory standards in the U.S. have resulted in substantial improvements in public transit accessibility. However, passengers using wheeled mobility devices still experience safety concerns and inefficiencies in boarding, disembarking, and interior circulation on low-floor buses. This study investigates effects of low-floor bus interior configuration and passenger crowding on boarding and disembarking efficiency and safety. Users of manual wheelchairs (n = 18), powered wheelchairs (n = 21) and electric scooters (n = 9) simulated boarding and disembarking in three interior layout configurations at low and high passenger crowding conditions on a full-scale laboratory mock-up of a low-floor bus. Dependent measures comprised task times and critical incidents during access ramp use, fare payment, and movement to and from the doorway and wheeled mobility securement area. Individual times for unassisted boarding ranged from 15.2 to 245.3 s and for disembarking ranged from 9.1 to 164.6 s across layout and passenger crowding conditions. Nonparametric analysis of variance showed significant differences and interactions across vehicle design conditions, passenger load and mobility device type on user performance. The configuration having electronic on-board fare payment, rear-bus entrance doorways and adjacent device securement areas demonstrated greatest efficiency and safety. High passenger load adversely impacted efficiency and frequency of critical incidents during on-board circulation across all three layouts. Findings have broader implications for improving transit system efficiency and quality of service across the spectrum of transit users. Copyright © 2017 Elsevier Ltd. All rights reserved.

System design of the Pioneer Venus spacecraft. Volume 3: Systems analysis

NASA Technical Reports Server (NTRS)

Fisher, J. N.

1973-01-01

The mission, systems, operations, ground systems, and reliability analysis of the Thor/Delta baseline design used for the Pioneer Space Probe are discussed. Tradeoff decisions concerning spin axis orientation, bus antenna design, communication system design, probe descent, and reduced science payload are analyzed. The reliability analysis is made for the probe bus mission, large probe mission, and small probe mission. Detailed mission sequences were established to identify critical areas and provide phasing of critical operation.

Deregulation and Intercity Bus Operations in Florida: A Preliminary Study.

DTIC Science & Technology

1981-03-02

revenues have been consistent recently, but expenses have risen. The three areas most frequently served by Rabbit Bus Lines are Disney World, Sea World...Manager, Shoreline Stages had annual revenues of roughly $890,000 in 1980. In terms of trips, about ninety percent of this carrier’s traffic is interstate...this traffic constitutes the bulk of Shoreline Stage’s business by revenue , volume of traffic, and number of passengers. Charter trips to Disney

HyspIRI Intelligent Payload Module(IPM) and Benchmarking Algorithms for Upload

NASA Technical Reports Server (NTRS)

Mandl, Daniel

2010-01-01

Features: Hardware: a) Xilinx Virtex-5 (GSFC Space Cube 2); b) 2 x 400MHz PPC; c) 100MHz Bus; d) 2 x 512MB SDRAM; e) Dual Gigabit Ethernet. Support Linux kernel 2.6.31 (gcc version 4.2.2). Support software running in stand alone mode for better performance. Can stream raw data up to 800 Mbps. Ready for operations. Software Application Examples: Band-stripping Algiotrhmsl:cloud, sulfur, flood, thermal, SWIL, NDVI, NDWI, SIWI, oil spills, algae blooms, etc. Corrections: geometric, radiometric, atmospheric. Core Flight System/dynamic software bus. CCSDS File Delivery Protocol. Delay Tolerant Network. CASPER /onboard planning. Fault monitoring/recovery software. S/C command and telemetry software. Data compression. Sensor Web for Autonomous Mission Operations.

Topological Quantum Buses: Coherent Quantum Information Transfer between Topological and Conventional Qubits

NASA Astrophysics Data System (ADS)

Bonderson, Parsa; Lutchyn, Roman M.

2011-04-01

We propose computing bus devices that enable quantum information to be coherently transferred between topological and conventional qubits. We describe a concrete realization of such a topological quantum bus acting between a topological qubit in a Majorana wire network and a conventional semiconductor double quantum dot qubit. Specifically, this device measures the joint (fermion) parity of these two different qubits by using the Aharonov-Casher effect in conjunction with an ancilliary superconducting flux qubit that facilitates the measurement. Such a parity measurement, together with the ability to apply Hadamard gates to the two qubits, allows one to produce states in which the topological and conventional qubits are maximally entangled and to teleport quantum states between the topological and conventional quantum systems.

Property relationships of the physical infrastructure and the traffic flow networks

NASA Astrophysics Data System (ADS)

Zhou, Ta; Zou, Sheng-Rong; He, Da-Ren

2010-03-01

We studied both empirically and analytically the correlation between the degrees or the clustering coefficients, respectively, of the networks in the physical infrastructure and the traffic flow layers in three Chinese transportation systems. The systems are bus transportation systems in Beijing and Hangzhou, and the railway system in the mainland. It is found that the correlation between the degrees obey a linear function; while the correlation between the clustering coefficients obey a power law. A possible dynamic explanation on the rules is presented.

Active distribution network planning considering linearized system loss

NASA Astrophysics Data System (ADS)

Li, Xiao; Wang, Mingqiang; Xu, Hao

2018-02-01

In this paper, various distribution network planning techniques with DGs are reviewed, and a new distribution network planning method is proposed. It assumes that the location of DGs and the topology of the network are fixed. The proposed model optimizes the capacities of DG and the optimal distribution line capacity simultaneously by a cost/benefit analysis and the benefit is quantified by the reduction of the expected interruption cost. Besides, the network loss is explicitly analyzed in the paper. For simplicity, the network loss is appropriately simplified as a quadratic function of difference of voltage phase angle. Then it is further piecewise linearized. In this paper, a piecewise linearization technique with different segment lengths is proposed. To validate its effectiveness and superiority, the proposed distribution network planning model with elaborate linearization technique is tested on the IEEE 33-bus distribution network system.

Empirical study on dyad act-degree distribution in some collaboration networks

NASA Astrophysics Data System (ADS)

Chang, Hui; Zhang, Pei-Pei; He, Yue; He, Da-Ren

2006-03-01

We (and cooperators) suggest studying the evolution of the extended collaboration networks by a dyad-act organizing model. The analytic and numeric studies of the model lead to a conclusion that most of the collaboration networks should show a dyad act-degree distribution (how many acts a dyad belongs to) between a power law and an exponential function, which can be described by a shifted power law. We have done an empirical study on dyad act-degree distribution in some collaboration networks. They are: the train networks in China, the bus network of Beijing, and traditional Chinese medical prescription formulation network. The results show good agreement with this conclusion. We also discuss what dyad act-degree implies in these networks and what are the possible applications of the study. The details will be published elsewhere.

Bedside ultrasound curriculum for medical students: report of a blended learning curriculum implementation and validation.

PubMed

Blackstock, Uché; Munson, Jaclyn; Szyld, Demian

2015-03-01

Medical students on clinical rotations rarely receive formal bedside ultrasound (BUS) training. We designed, implemented, and evaluated a standardized BUS curriculum for medical students on their Emergency Medicine (EM) rotation. Teaching was aimed toward influencing four cognitive and psychomotor learning domains: BUS instrumentation knowledge, image interpretation, image acquisition, and procedural guidance. Participants viewed three instructional Web-based tutorials on BUS instrumentation, the Focused Assessment for Sonography in Trauma (FAST) examination and ultrasound-guided central venous catheter (CVC) placement. Subsequently, participants attended a 3-hour hands-on training session to discuss the same content area and practice with faculty coaches. A Web-based, multiple-choice questionnaire was administered before and after the session. During the final week of the rotation, students returned for skills assessments on FAST image acquisition and CVC placement. Forty-five medical students on an EM rotation were enrolled. Sonographic knowledge overall mean score improved significantly from 66.6% (SD ±11.2) to 85.7% (SD ±10.0), corresponding to a mean difference of 19.1% (95% CI 15.5-22.7; p < 0.001). There were high pass rates for FAST (89.0%, 40/45) and CVC (96.0%, 43/45) skills assessments. There was no significant difference between medical student posttest and EM resident test scores 85.7% (SD ±10.0) and 88.1% (SD ± 7.6) (p = 0.40), respectively. A formal BUS curriculum for medical students on EM rotation positively influenced performance in several key learning domains. As BUS competency is required for residency in EM and other specialties, medical schools could consider routinely incorporating BUS teaching into their clinical rotation curricula. © 2014 Wiley Periodicals, Inc.

Bus Stops Location and Bus Route Planning Using Mean Shift Clustering and Ant Colony in West Jakarta

NASA Astrophysics Data System (ADS)

Supangat, Kenny; Eko Soelistio, Yustinus

2017-03-01

Traffic Jam has been a daily problem for people in Jakarta which is one of the busiest city in Indonesia up until now. Even though the official government has tried to reduce the impact of traffic issues by developing a new public transportation which takes up a lot of resources and time, it failed to diminish the problem. The actual concern to this problem actually lies in how people move between places in Jakarta where they always using their own vehicle like cars, and motorcycles that fill most of the street in Jakarta. Among much other public transportations that roams the street of Jakarta, Buses is believed to be an efficient transportation that can move many people at once. However, the location of the bus stop is now have moved to the middle of the main road, and its too far for the nearby residence to access to it. This paper proposes an optimal location of optimal bus stops in West Jakarta that is experimentally proven to have a maximal distance of 350 m. The optimal location is estimated by means of mean shift clustering method while the optimal routes are calculated using Ant Colony algorithm. The bus stops locations rate of error is 0.07% with overall route area of 32 km. Based on our experiments, we believe our proposed bus stop plan can be an interesting alternative to reduce traffic congestion in West Jakarta.

6. SECOND FLOOR, LOOKING SOUTHEAST, AREA PREVIOUSLY CONTAINED HIGH TENSION ...

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

6. SECOND FLOOR, LOOKING SOUTHEAST, AREA PREVIOUSLY CONTAINED HIGH TENSION BUS AND SWITCHING EQUIPMENT FOR BUILDINGS L1 AND L2 - Portland General Electric Company, Lincoln Substation, 1841 Southeast Water Street, Portland, Multnomah County, OR

5. WEST MEZZANINE, LOOKING NORTH, AREA PREVIOUSLY CONTAINED HIGH TENSION ...

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

5. WEST MEZZANINE, LOOKING NORTH, AREA PREVIOUSLY CONTAINED HIGH TENSION BUS AND SWITCHING EQUIPMENT FOR BUILDINGS L1 AND L2 - Portland General Electric Company, Lincoln Substation, 1841 Southeast Water Street, Portland, Multnomah County, OR

Next Generation Instrumentation Bus Test Plan for Fibre Channel

DTIC Science & Technology

1999-09-30

sample for port testing. The heart of the Fibre Xpress network cards is the tachyon chip from Hewlett Packard. The tachyon chip is basically a single...be to test the protocols. 1.5.1.1 Tachyon chip The user’s manual for the Tachyon controller chip identifies the following FC-AL specification

Alternative Fuels Data Center: Pennsylvania Transportation Data for

Science.gov Websites

/TTIwZrpNGf4 Video thumbnail for Pennsylvania School Buses Run on Natural Gas Pennsylvania School Buses Run on Network, Clean School Bus/Vehicle Incentive, and Green Jobs Outreach Program Independence National Partnership for Promoting Natural Gas Vehicles Ready to Roll! - Southeastern Pennsylvania's Regional Electric

The Fuel Efficient Missile Combat Crew Routing Network.

DTIC Science & Technology

1980-06-01

after a 24 -hour alert tour, driving safety might be impacted. Al- though the 1.98 gallons per passenger is a 43% improvement over the present MCC...Van/DS II, Van/DS I, and 29 Pax Bus/ DS I combinations, the authors believe that the potential lengthy travel times, driving safety factor, vehicle

Multinode data acquisition and control system for the 4-element TACTIC telescope array

NASA Astrophysics Data System (ADS)

Yadav, K. K.; Chouhan, N.; Kaul, S. R.; Koul, R.

2002-03-01

An interrupt driven multinode data acquisition and control system has been developed for the 4-element gamma-ray telescope array, TACTIC. Computer networking technology and the CAMAC bus have been integrated to develop this icon-based, userfriendly failsafe system. The paper describes the salient features of the system.

Computer hardware for radiologists: Part 2

PubMed Central

Indrajit, IK; Alam, A

2010-01-01

Computers are an integral part of modern radiology equipment. In the first half of this two-part article, we dwelt upon some fundamental concepts regarding computer hardware, covering components like motherboard, central processing unit (CPU), chipset, random access memory (RAM), and memory modules. In this article, we describe the remaining computer hardware components that are of relevance to radiology. “Storage drive” is a term describing a “memory” hardware used to store data for later retrieval. Commonly used storage drives are hard drives, floppy drives, optical drives, flash drives, and network drives. The capacity of a hard drive is dependent on many factors, including the number of disk sides, number of tracks per side, number of sectors on each track, and the amount of data that can be stored in each sector. “Drive interfaces” connect hard drives and optical drives to a computer. The connections of such drives require both a power cable and a data cable. The four most popular “input/output devices” used commonly with computers are the printer, monitor, mouse, and keyboard. The “bus” is a built-in electronic signal pathway in the motherboard to permit efficient and uninterrupted data transfer. A motherboard can have several buses, including the system bus, the PCI express bus, the PCI bus, the AGP bus, and the (outdated) ISA bus. “Ports” are the location at which external devices are connected to a computer motherboard. All commonly used peripheral devices, such as printers, scanners, and portable drives, need ports. A working knowledge of computers is necessary for the radiologist if the workflow is to realize its full potential and, besides, this knowledge will prepare the radiologist for the coming innovations in the ‘ever increasing’ digital future. PMID:21423895

Investigation of bus transit schedule behavior modeling using advanced techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kalaputapu, R.; Demetsky, M.J.

This research focused on investigating the application of artificial neural networks (ANN) and the Box-Jenkins technique for developing and testing schedule behavior models using data obtained for a test route from Tidewater Regional Transit`s AVL system. The three ANN architectures investigated were: Feedforward Network, Elman Network and Jordan Network. In addition, five different model structures were investigated. The time-series methodology was adopted for developing the schedule behavior models. Finally, the role of a schedule behavior model within the framework of an intelligent transit management system is defined and the potential utility of the schedule behavior model is discussed using anmore » example application.« less

Understanding spatio-temporal mobility patterns for seniors, child/student and adult using smart card data

NASA Astrophysics Data System (ADS)

Huang, X.; Tan, J.

2014-11-01

Commutes in urban areas create interesting travel patterns that are often stored in regional transportation databases. These patterns can vary based on the day of the week, the time of the day, and commuter type. This study proposes methods to detect underlying spatio-temporal variability among three groups of commuters (senior citizens, child/students, and adults) using data mining and spatial analytics. Data from over 36 million individual trip records collected over one week (March 2012) on the Singapore bus and Mass Rapid Transit (MRT) system by the fare collection system were used. Analyses of such data are important for transportation and landuse designers and contribute to a better understanding of urban dynamics. Specifically, descriptive statistics, network analysis, and spatial analysis methods are presented. Descriptive variables were proposed such as density and duration to detect temporal features of people. A directed weighted graph G ≡ (N , L, W) was defined to analyze the global network properties of every pair of the transportation link in the city during an average workday for all three categories. Besides, spatial interpolation and spatial statistic tools were used to transform the discrete network nodes into structured human movement landscape to understand the role of transportation systems in urban areas. The travel behaviour of the three categories follows a certain degree of temporal and spatial universality but also displays unique patterns within their own specialties. Each category is characterized by their different peak hours, commute distances, and specific locations for travel on weekdays.

Bluetooth wireless monitoring, diagnosis and calibration interface for control system of fuel cell bus in Olympic demonstration

NASA Astrophysics Data System (ADS)

Hua, Jianfeng; Lin, Xinfan; Xu, Liangfei; Li, Jianqiu; Ouyang, Minggao

With the worldwide deterioration of the natural environment and the fossil fuel crisis, the possible commercialization of fuel cell vehicles has become a hot topic. In July 2008, Beijing started a clean public transportation plan for the 29th Olympic games. Three fuel cell city buses and 497 other low-emission vehicles are now serving the Olympic core area and Beijing urban areas. The fuel cell buses will operate along a fixed bus line for 1 year as a public demonstration of green energy vehicles. Due to the specialized nature of fuel cell engines and electrified power-train systems, measurement, monitoring and calibration devices are indispensable. Based on the latest Bluetooth wireless technology, a novel Bluetooth universal data interface was developed for the control system of the fuel cell city bus. On this platform, a series of wireless portable control auxiliary systems have been implemented, including wireless calibration, a monitoring system and an in-system programming platform, all of which are ensuring normal operation of the fuel cell buses used in the demonstration.

Improvised Explosive Devise Placement Detection from a Semi-Autonomous Ground Vehicle

DTIC Science & Technology

2006-12-01

is not autonomous, weighs approximately 100 lbs , costs well over $50,000, and has dimensions of approximately 3’ x 2’ x 3’ [Ref. 2]. These factors...bottom. 2. Power Bus and Battery The power bus with battery consists of all commercial off the shelf (COTS) products. The battery (Figure 10) is...camera is mounted on AGV’s shelf , above the motion detectors (future locations will include a more protected area). Figure 29. D-Link, DCS-900

An Artificially Intelligent Physical Model-Checking Approach to Detect Switching-Related Attacks on Power Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

El Hariri, Mohamad; Faddel, Samy; Mohammed, Osama

Decentralized and hierarchical microgrid control strategies have lain the groundwork for shaping the future smart grid. Such control approaches require the cooperation between microgrid operators in control centers, intelligent microcontrollers, and remote terminal units via secure and reliable communication networks. In order to enhance the security and complement the work of network intrusion detection systems, this paper presents an artificially intelligent physical model-checking that detects tampered-with circuit breaker switching control commands whether, due to a cyber-attack or human error. In this technique, distributed agents, which are monitoring sectionalized areas of a given microgrid, will be trained and continuously adapted tomore » verify that incoming control commands do not violate the physical system operational standards and do not put the microgrid in an insecure state. The potential of this approach has been tested by deploying agents that monitor circuit breakers status commands on a 14-bus IEEE benchmark system. The results showed the accuracy of the proposed framework in characterizing the power system and successfully detecting malicious and/or erroneous control commands.« less

Optimal placement and sizing of wind / solar based DG sources in distribution system

NASA Astrophysics Data System (ADS)

Guan, Wanlin; Guo, Niao; Yu, Chunlai; Chen, Xiaoguang; Yu, Haiyang; Liu, Zhipeng; Cui, Jiapeng

2017-06-01

Proper placement and sizing of Distributed Generation (DG) in distribution system can obtain maximum potential benefits. This paper proposes quantum particle swarm algorithm (QPSO) based wind turbine generation unit (WTGU) and photovoltaic (PV) array placement and sizing approach for real power loss reduction and voltage stability improvement of distribution system. Performance modeling of wind and solar generation system are described and classified into PQ\\PQ (V)\\PI type models in power flow. Considering the WTGU and PV based DGs in distribution system is geographical restrictive, the optimal area and DG capacity limits of each bus in the setting area need to be set before optimization, the area optimization method is proposed . The method has been tested on IEEE 33-bus radial distribution systems to demonstrate the performance and effectiveness of the proposed method.

Spacecraft Bus and Platform Technology Development under the NASA ISPT Program

NASA Technical Reports Server (NTRS)

Anderson, David J.; Munk, Michelle M.; Pencil, Eric; Dankanich, John; Glaab, Louis; Peterson, Todd

2013-01-01

The In-Space Propulsion Technology (ISPT) program is developing spacecraft bus and platform technologies that will enable or enhance NASA robotic science missions. The ISPT program is currently developing technology in four areas that include Propulsion System Technologies (electric and chemical), Entry Vehicle Technologies (aerocapture and Earth entry vehicles), Spacecraft Bus and Sample Return Propulsion Technologies (components and ascent vehicles), and Systems/Mission Analysis. Three technologies are ready for near-term flight infusion: 1) the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance; 2) NASA s Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system; and 3) Aerocapture technology development with investments in a family of thermal protection system (TPS) materials and structures; guidance, navigation, and control (GN&C) models of blunt-body rigid aeroshells; and aerothermal effect models. Two component technologies being developed with flight infusion in mind are the Advanced Xenon Flow Control System, and ultra-lightweight propellant tank technologies. Future direction for ISPT are technologies that relate to sample return missions and other spacecraft bus technology needs like: 1) Mars Ascent Vehicles (MAV); 2) multi-mission technologies for Earth Entry Vehicles (MMEEV) for sample return missions; and 3) electric propulsion for sample return and low cost missions. These technologies are more vehicle and mission-focused, and present a different set of technology development and infusion steps beyond those previously implemented. The Systems/Mission Analysis area is focused on developing tools and assessing the application of propulsion and spacecraft bus technologies to a wide variety of mission concepts. These in-space propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, and sample return missions currently under consideration, as well as having broad applicability to potential Flagship missions. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness of in-space propulsion technologies in the areas of electric propulsion, Aerocapture, Earth entry vehicles, propulsion components, Mars ascent vehicle, and mission/systems analysis.

Spacecraft Bus and Platform Technology Development under the NASA ISPT Program

NASA Technical Reports Server (NTRS)

Anderson, David J.; Munk, Michelle M.; Pencil, Eric J.; Dankanich, John W.; Glaab, Louis J.; Peterson, Todd T.

2013-01-01

The In-Space Propulsion Technology (ISPT) program is developing spacecraft bus and platform technologies that will enable or enhance NASA robotic science missions. The ISPT program is currently developing technology in four areas that include Propulsion System Technologies (electric and chemical), Entry Vehicle Technologies (aerocapture and Earth entry vehicles), Spacecraft Bus and Sample Return Propulsion Technologies (components and ascent vehicles), and Systems/Mission Analysis. Three technologies are ready for near-term flight infusion: 1) the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance 2) NASAs Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system and 3) Aerocapture technology development with investments in a family of thermal protection system (TPS) materials and structures guidance, navigation, and control (GN&C) models of blunt-body rigid aeroshells and aerothermal effect models. Two component technologies being developed with flight infusion in mind are the Advanced Xenon Flow Control System, and ultra-lightweight propellant tank technologies. Future direction for ISPT are technologies that relate to sample return missions and other spacecraft bus technology needs like: 1) Mars Ascent Vehicles (MAV) 2) multi-mission technologies for Earth Entry Vehicles (MMEEV) for sample return missions and 3) electric propulsion for sample return and low cost missions. These technologies are more vehicle and mission-focused, and present a different set of technology development and infusion steps beyond those previously implemented. The Systems/Mission Analysis area is focused on developing tools and assessing the application of propulsion and spacecraft bus technologies to a wide variety of mission concepts. These in-space propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, and sample return missions currently under consideration, as well as having broad applicability to potential Flagship missions. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness of in-space propulsion technologies in the areas of electric propulsion, Aerocapture, Earth entry vehicles, propulsion components, Mars ascent vehicle, and mission/systems analysis.

Heterogeneity of passenger exposure to air pollutants in public transport microenvironments

NASA Astrophysics Data System (ADS)

Yang, Fenhuan; Kaul, Daya; Wong, Ka Chun; Westerdahl, Dane; Sun, Li; Ho, Kin-fai; Tian, Linwei; Brimblecombe, Peter; Ning, Zhi

2015-05-01

Epidemiologic studies have linked human exposure to pollutants with adverse health effects. Passenger exposure in public transport systems contributes an important fraction of daily burden of air pollutants. While there is extensive literature reporting the concentrations of pollutants in public transport systems in different cities, there are few studies systematically addressing the heterogeneity of passenger exposure in different transit microenvironments, in cabins of different transit vehicles and in areas with different characteristics. The present study investigated PM2.5 (particulate matter with aerodynamic diameters smaller than 2.5 μm), black carbon (BC), ultrafine particles (UFP) and carbon monoxide (CO) pollutant concentrations in various public road transport systems in highly urbanized city of Hong Kong. Using a trolley case housing numerous portable air monitors, we conducted a total of 119 trips during the campaign. Transit microenvironments, classified as 1). busy and secondary roadside bus stops; 2). open and enclosed termini; 3). above- and under-ground Motor Rail Transport (MTR) platforms, were investigated and compared to identify the factors that may affect passenger exposures. The pollutants inside bus and MTR cabins were also investigated together with a comparison of time integrated exposure between the transit modes. Busy roadside and enclosed termini demonstrated the highest average particle concentrations while the lowest was found on the MTR platforms. Traffic-related pollutants BC, UFP and CO showed larger variations than PM2.5 across different microenvironments and areas confirming their heterogeneity in urban environments. In-cabin pollutant concentrations showed distinct patterns with BC and UFP high in diesel bus cabins and CO high in LPG bus cabins, suggesting possible self-pollution issues and/or penetration of on-road pollutants inside cabins during bus transit. The total passenger exposure along selected routes, showed bus trips had the potential for higher integrated passenger exposure compared to MTR trips. The present study may provide useful information to better characterize the distribution of passenger exposure pattern in health assessment studies and the results also highlight the need to formulate exposure reduction based air policies in large cities.

Violence against metropolitan bus drivers and fare collectors in Brazil

PubMed Central

Assunção, Ada Ávila; de Medeiros, Adriane Mesquita

2015-01-01

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

a Mini Multi-Gas Detection System Based on Infrared Principle

NASA Astrophysics Data System (ADS)

Zhijian, Xie; Qiulin, Tan

2006-12-01

To counter the problems of gas accidents in coal mines, family safety resulted from using gas, a new infrared detection system with integration and miniaturization has been developed. The infrared detection optics principle used in developing this system is mainly analyzed. The idea that multi gas detection is introduced and guided through analyzing single gas detection is got across. Through researching the design of cell structure, the cell with integration and miniaturization has been devised. The way of data transmission on Controller Area Network (CAN) bus is explained. By taking Single-Chip Microcomputer (SCM) as intelligence handling, the functional block diagram of gas detection system is designed with its hardware and software system analyzed and devised. This system designed has reached the technology requirement of lower power consumption, mini-volume, big measure range, and able to realize multi-gas detection.

Coordinated control of active and reactive power of distribution network with distributed PV cluster via model predictive control

NASA Astrophysics Data System (ADS)

Ji, Yu; Sheng, Wanxing; Jin, Wei; Wu, Ming; Liu, Haitao; Chen, Feng

2018-02-01

A coordinated optimal control method of active and reactive power of distribution network with distributed PV cluster based on model predictive control is proposed in this paper. The method divides the control process into long-time scale optimal control and short-time scale optimal control with multi-step optimization. The models are transformed into a second-order cone programming problem due to the non-convex and nonlinear of the optimal models which are hard to be solved. An improved IEEE 33-bus distribution network system is used to analyse the feasibility and the effectiveness of the proposed control method

7. SECOND FLOOR, EAST SIDE OF BUILDING LOOKING SOUTHEAST, AREA ...

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

7. SECOND FLOOR, EAST SIDE OF BUILDING LOOKING SOUTHEAST, AREA PREVIOUSLY CONTAINED HIGH TENSION BUS AND SWITCHING EQUIPMENT FOR BUILDINGS L1 AND L2 - Portland General Electric Company, Lincoln Substation, 1841 Southeast Water Street, Portland, Multnomah County, OR

Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration Results: Sixth Report

DOT National Transportation Integrated Search

2017-09-01

This report presents results of a demonstration of fuel cell electric buses (FCEBs) operating in Oakland, California. Alameda-Contra Costa Transit District (AC Transit) leads the Zero Emission Bay Area (ZEBA) demonstration that includes 13 advanced-d...

Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration Results : Fourth Report

DOT National Transportation Integrated Search

2015-07-04

This report presents results of a demonstration of fuel cell electric buses (FCEB) operating in Oakland, California. Alameda-Contra Costa Transit District (AC Transit) leads the Zero Emission Bay Area (ZEBA) demonstration, which includes 12 advanced-...

Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration Results : Fifth Report

DOT National Transportation Integrated Search

2016-06-01

This report presents results of a demonstration of fuel cell electric buses (FCEBs) operating in Oakland, California. Alameda-Contra Costa Transit District (AC Transit) leads the Zero Emission Bay Area (ZEBA) demonstration, which includes 13 advanced...

Land Ecological on Public Transport Infrastructure Development In Indonesia

NASA Astrophysics Data System (ADS)

Sari, N.

2017-10-01

The development of public transport infrastructure in Indonesia has been growing rapidly since the last five years. The utilization of area as public transport infrastructure, for example bus depot, bus Station and terminal requires wide area and influences many elements, such as land ecological quality, water supplies, power supplies, and environmental balance. However the development of public transport infrastructure now days is less considering on environmental approach, especially for green and catchment area for water conservation (water balance).This paper aims to propose the concept of Public Transport Infrastructure using green concept. The green design concept is using GBCI (Green Building Council Indonesia) standard, which contains seven categories: land ecological enhancement, movement and connectivity, water management and conservation, solid waste and material, community wellbeing strategy, building and energy, and also innovation and future development. The result is, by using the GBCI standard for the green design of Public Transport Infrastructure, the land ecological impact could be decreased. The effective areas that required are at least 5000 m2, from which the green areas for public increase 36% and 76% of areas could be used as catchment area for water conservation.

Topological quantum buses: coherent quantum information transfer between topological and conventional qubits.

PubMed

Bonderson, Parsa; Lutchyn, Roman M

2011-04-01

We propose computing bus devices that enable quantum information to be coherently transferred between topological and conventional qubits. We describe a concrete realization of such a topological quantum bus acting between a topological qubit in a Majorana wire network and a conventional semiconductor double quantum dot qubit. Specifically, this device measures the joint (fermion) parity of these two different qubits by using the Aharonov-Casher effect in conjunction with an ancilliary superconducting flux qubit that facilitates the measurement. Such a parity measurement, together with the ability to apply Hadamard gates to the two qubits, allows one to produce states in which the topological and conventional qubits are maximally entangled and to teleport quantum states between the topological and conventional quantum systems. © 2011 American Physical Society

High speed bus technology development

NASA Astrophysics Data System (ADS)

Modrow, Marlan B.; Hatfield, Donald W.

1989-09-01

The development and demonstration of the High Speed Data Bus system, a 50 Million bits per second (Mbps) local data network intended for avionics applications in advanced military aircraft is described. The Advanced System Avionics (ASA)/PAVE PILLAR program provided the avionics architecture concept and basic requirements. Designs for wire and fiber optic media were produced and hardware demonstrations were performed. An efficient, robust token-passing protocol was developed and partially demonstrated. The requirements specifications, the trade-offs made, and the resulting designs for both a coaxial wire media system and a fiber optics design are examined. Also, the development of a message-oriented media access protocol is described, from requirements definition through analysis, simulation and experimentation. Finally, the testing and demonstrations conducted on the breadboard and brassboard hardware is presented.

Risk Management: Supporting the District's Ancillary Services Staff

ERIC Educational Resources Information Center

Waldmann, Steve; Strasburger, Tom

2013-01-01

The everyday operations of a school district depend on a network of people, including students, teachers, staff, and administrators. However, the ancillary services staff are really responsible for making the school day run smoothly. They are often the first employees that students see in the morning, either on the school bus or in the cafeteria,…

Accessible Bus Service in the Washington, D.C. Metropolitan Area.

DOT National Transportation Integrated Search

1983-01-01

The Washington Metropolitan Area Transit Authority (WMATA) began operation of lift-equipped fixed-route service on several of its Metrobus routes in July 1979. Using 151 Flxible buses equipped with Vapor front-door lift devices, WMATA made 8% of its ...

Formed photovoltaic module busbars

DOEpatents

Rose, Douglas; Daroczi, Shan; Phu, Thomas

2015-11-10

A cell connection piece for a photovoltaic module is disclosed herein. The cell connection piece includes an interconnect bus, a plurality of bus tabs unitarily formed with the interconnect bus, and a terminal bus coupled with the interconnect bus. The plurality of bus tabs extend from the interconnect bus. The terminal bus includes a non-linear portion.

Use of CCSDS Packets Over SpaceWire to Control Hardware

NASA Technical Reports Server (NTRS)

Haddad, Omar; Blau, Michael; Haghani, Noosha; Yuknis, William; Albaijes, Dennis

2012-01-01

For the Lunar Reconnaissance Orbiter, the Command and Data Handling subsystem consisted of several electronic hardware assemblies that were connected with SpaceWire serial links. Electronic hardware would be commanded/controlled and telemetry data was obtained using the SpaceWire links. Prior art focused on parallel data buses and other types of serial buses, which were not compatible with the SpaceWire and the core flight executive (CFE) software bus. This innovation applies to anything that utilizes both SpaceWire networks and the CFE software. The CCSDS (Consultative Committee for Space Data Systems) packet contains predetermined values in its payload fields that electronic hardware attached at the terminus of the SpaceWire node would decode, interpret, and execute. The hardware s interpretation of the packet data would enable the hardware to change its state/configuration (command) or generate status (telemetry). The primary purpose is to provide an interface that is compatible with the hardware and the CFE software bus. By specifying the format of the CCSDS packet, it is possible to specify how the resulting hardware is to be built (in terms of digital logic) that results in a hardware design that can be controlled by the CFE software bus in the final application

COTS-Based Fault Tolerance in Deep Space: Qualitative and Quantitative Analyses of a Bus Network Architecture

NASA Technical Reports Server (NTRS)

Tai, Ann T.; Chau, Savio N.; Alkalai, Leon

2000-01-01

Using COTS products, standards and intellectual properties (IPs) for all the system and component interfaces is a crucial step toward significant reduction of both system cost and development cost as the COTS interfaces enable other COTS products and IPs to be readily accommodated by the target system architecture. With respect to the long-term survivable systems for deep-space missions, the major challenge for us is, under stringent power and mass constraints, to achieve ultra-high reliability of the system comprising COTS products and standards that are not developed for mission-critical applications. The spirit of our solution is to exploit the pertinent standard features of a COTS product to circumvent its shortcomings, though these standard features may not be originally designed for highly reliable systems. In this paper, we discuss our experiences and findings on the design of an IEEE 1394 compliant fault-tolerant COTS-based bus architecture. We first derive and qualitatively analyze a -'stacktree topology" that not only complies with IEEE 1394 but also enables the implementation of a fault-tolerant bus architecture without node redundancy. We then present a quantitative evaluation that demonstrates significant reliability improvement from the COTS-based fault tolerance.

Placement of Synchronized Measurements for Power System Observability during Cascaded Outages

NASA Astrophysics Data System (ADS)

Thirugnanasambandam, Venkatesh; Jain, Trapti

2017-11-01

Cascaded outages often result in power system islanding followed by a blackout and therefore considered as a severe disturbance. Maintaining the observability of each island may help in taking proper control actions to preserve the stability of individual islands thus, averting system collapse. With this intent, a strategy for placement of synchronized measurements, which can be obtained from phasor measurement units (PMU), has been proposed in this paper to keep the system observable during cascaded outages also. Since, all the cascaded failures may not lead to islanding situations, therefore, failures leading to islanding as well as non-islanding situations have been considered. A topology based algorithm has been developed to identify the islanding/non-islanding condition created by a particular cascaded event. Additional contingencies such as single line loss and single PMU failure have also been considered after the occurrence of cascaded events. The proposed method is further extended to incorporate the measurement redundancy, which is desirable for a reliable state estimation. The proposed scheme is tested on IEEE 14-bus, IEEE 30-bus and a practical Indian 246-bus networks. The numerical results ensure the observability of the power system under system intact as well as during cascaded islanding and non-islanding disturbances.

Ambient levels of carbonyl compounds and their sources in Guangzhou, China

NASA Astrophysics Data System (ADS)

Feng, Yanli; Wen, Sheng; Chen, Yingjun; Wang, Xinming; Lü, Huixiong; Bi, Xinhui; Sheng, Guoying; Fu, Jiamo

Ambient levels of carbonyl compounds and their possible sources, vehicular exhaust and cooking exhaust, were studied at seven places in Guangzhou, including five districts (a residential area, an industrial area, a botanical garden, a downtown area and a semi-rural area), a bus station and a restaurant during the period of June-September 2003. Nineteen carbonyl compounds were identified in the ambient air, of which acetone was the most abundant carbonyl, followed by formaldehyde and acetaldehyde. Only little changes were found in carbonyl concentration levels in the five different districts because of their dispersion and mixture in the atmosphere in summer. The lower correlations between the carbonyls' concentrations might result from the mixture of carbonyls derived from different sources, including strong photochemical reactions at noon in summer. Formaldehyde and acetaldehyde were the main carbonyls in bus station, while straight-chain carbonyls were comparatively abundant in cooking exhaust. Besides vehicular exhaust, cooking might be another major source of carbonyl compounds in Guangzhou City, especially for high molecular weight carbonyls.

Commuting to school and to work among high school students in Santa Catarina state, Brazil: a comparative analysis between 2001 and 2011.

PubMed

Silva, Kelly Samara; Lopes, Adair da Silva; Hardman, Carla Menêses; Cabral, Luciana Gatto Azevedo; da Silva, Shana Ginar; Nahas, Markus Vinicius

2014-11-01

Commuting reflects an important opportunity for youth to engage in physical activity. This study aimed to compare modes of commuting to school and to work and to identify sociodemographic factors associated with various modes of transportation. Epidemiologic study with a repeated cross-sectional design. Participants included high school students (15-19 years of age) from Santa Catarina state, Brazil, in 2001 (n = 5028) and 2011 (n = 6529). A questionnaire containing information on the type of transport used to commute to school and to work was administered. Walking/bicycling and the use of the bus to commute to school and to work remained stable after a decade; however, the use of car/motorcycle to school (6.4% versus 12.6%) and to work (10.2% versus 19.7%) increased significantly. In both cases, females more frequently used buses, whereas males commuted to work by car/bus. Students from rural areas more commonly commuted to school by car/motorcycle, whereas those from urban areas traveled to work more by bus. There was a greater use of cars/motorcycles by young people from higher-income families. The use of cars/motorcycles to commute to school/work has almost doubled in the last decade. Sex, residential area and income were associated with passive commuting.

Optimal Siting and Sizing of Multiple DG Units for the Enhancement of Voltage Profile and Loss Minimization in Transmission Systems Using Nature Inspired Algorithms

PubMed Central

Ramamoorthy, Ambika; Ramachandran, Rajeswari

2016-01-01

Power grid becomes smarter nowadays along with technological development. The benefits of smart grid can be enhanced through the integration of renewable energy sources. In this paper, several studies have been made to reconfigure a conventional network into a smart grid. Amongst all the renewable sources, solar power takes the prominent position due to its availability in abundance. Proposed methodology presented in this paper is aimed at minimizing network power losses and at improving the voltage stability within the frame work of system operation and security constraints in a transmission system. Locations and capacities of DGs have a significant impact on the system losses in a transmission system. In this paper, combined nature inspired algorithms are presented for optimal location and sizing of DGs. This paper proposes a two-step optimization technique in order to integrate DG. In a first step, the best size of DG is determined through PSO metaheuristics and the results obtained through PSO is tested for reverse power flow by negative load approach to find possible bus locations. Then, optimal location is found by Loss Sensitivity Factor (LSF) and weak (WK) bus methods and the results are compared. In a second step, optimal sizing of DGs is determined by PSO, GSA, and hybrid PSOGSA algorithms. Apart from optimal sizing and siting of DGs, different scenarios with number of DGs (3, 4, and 5) and PQ capacities of DGs (P alone, Q alone, and  P and Q both) are also analyzed and the results are analyzed in this paper. A detailed performance analysis is carried out on IEEE 30-bus system to demonstrate the effectiveness of the proposed methodology. PMID:27057557

Optimal Siting and Sizing of Multiple DG Units for the Enhancement of Voltage Profile and Loss Minimization in Transmission Systems Using Nature Inspired Algorithms.

PubMed

Ramamoorthy, Ambika; Ramachandran, Rajeswari

2016-01-01

Power grid becomes smarter nowadays along with technological development. The benefits of smart grid can be enhanced through the integration of renewable energy sources. In this paper, several studies have been made to reconfigure a conventional network into a smart grid. Amongst all the renewable sources, solar power takes the prominent position due to its availability in abundance. Proposed methodology presented in this paper is aimed at minimizing network power losses and at improving the voltage stability within the frame work of system operation and security constraints in a transmission system. Locations and capacities of DGs have a significant impact on the system losses in a transmission system. In this paper, combined nature inspired algorithms are presented for optimal location and sizing of DGs. This paper proposes a two-step optimization technique in order to integrate DG. In a first step, the best size of DG is determined through PSO metaheuristics and the results obtained through PSO is tested for reverse power flow by negative load approach to find possible bus locations. Then, optimal location is found by Loss Sensitivity Factor (LSF) and weak (WK) bus methods and the results are compared. In a second step, optimal sizing of DGs is determined by PSO, GSA, and hybrid PSOGSA algorithms. Apart from optimal sizing and siting of DGs, different scenarios with number of DGs (3, 4, and 5) and PQ capacities of DGs (P alone, Q alone, and P and Q both) are also analyzed and the results are analyzed in this paper. A detailed performance analysis is carried out on IEEE 30-bus system to demonstrate the effectiveness of the proposed methodology.

An Efficient Method of Sharing Mass Spatio-Temporal Trajectory Data Based on Cloudera Impala for Traffic Distribution Mapping in an Urban City.

PubMed

Zhou, Lianjie; Chen, Nengcheng; Yuan, Sai; Chen, Zeqiang

2016-10-29

The efficient sharing of spatio-temporal trajectory data is important to understand traffic congestion in mass data. However, the data volumes of bus networks in urban cities are growing rapidly, reaching daily volumes of one hundred million datapoints. Accessing and retrieving mass spatio-temporal trajectory data in any field is hard and inefficient due to limited computational capabilities and incomplete data organization mechanisms. Therefore, we propose an optimized and efficient spatio-temporal trajectory data retrieval method based on the Cloudera Impala query engine, called ESTRI, to enhance the efficiency of mass data sharing. As an excellent query tool for mass data, Impala can be applied for mass spatio-temporal trajectory data sharing. In ESTRI we extend the spatio-temporal trajectory data retrieval function of Impala and design a suitable data partitioning method. In our experiments, the Taiyuan BeiDou (BD) bus network is selected, containing 2300 buses with BD positioning sensors, producing 20 million records every day, resulting in two difficulties as described in the Introduction section. In addition, ESTRI and MongoDB are applied in experiments. The experiments show that ESTRI achieves the most efficient data retrieval compared to retrieval using MongoDB for data volumes of fifty million, one hundred million, one hundred and fifty million, and two hundred million. The performance of ESTRI is approximately seven times higher than that of MongoDB. The experiments show that ESTRI is an effective method for retrieving mass spatio-temporal trajectory data. Finally, bus distribution mapping in Taiyuan city is achieved, describing the buses density in different regions at different times throughout the day, which can be applied in future studies of transport, such as traffic scheduling, traffic planning and traffic behavior management in intelligent public transportation systems.

Space Station laboratory module power loading analysis

NASA Astrophysics Data System (ADS)

Fu, S. J.

1994-07-01

The electrical power system of Space Station Freedom is an isolated electrical power generation and distribution network designed to meet the demands of a large number of electrical loads. An algorithm is developed to determine the power bus loading status under normal operating conditions to ensure the supply meets demand. The probabilities of power availability for payload operations (experiments) are also derived.

Open Source Initiative Powers Real-Time Data Streams

NASA Technical Reports Server (NTRS)

2014-01-01

Under an SBIR contract with Dryden Flight Research Center, Creare Inc. developed a data collection tool called the Ring Buffered Network Bus. The technology has now been released under an open source license and is hosted by the Open Source DataTurbine Initiative. DataTurbine allows anyone to stream live data from sensors, labs, cameras, ocean buoys, cell phones, and more.

SNE Industrial Fieldbus Interface

NASA Technical Reports Server (NTRS)

Lucena, Angel; Raines, Matthew; Oostdyk, Rebecca; Mata, Carlos

2011-01-01

Programmable logic controllers (PLCs) have very limited diagnostic and no prognostic capabilities, while current smart sensor designs do not have the capability to communicate over Fieldbus networks. The aim is to interface smart sensors with PLCs so that health and status information, such as failure mode identification and measurement tolerance, can be communicated via an industrial Fieldbus such as ControlNet. The SNE Industrial Fieldbus Interface (SIFI) is an embedded device that acts as a communication module in a networked smart sensor. The purpose is to enable a smart sensor to communicate health and status information to other devices, such as PLCs, via an industrial Fieldbus networking protocol. The SNE (Smart Network Element) is attached to a commercial off-the-shelf Any bus-S interface module through the SIFI. Numerous Anybus-S modules are available, each one designed to interface with a specific Fieldbus. Development of the SIFI focused on communications using the ControlNet protocol, but any of the Anybus-S modules can be used. The SIFI communicates with the Any-bus module via a data buffer and mailbox system on the Anybus module, and supplies power to the module. The Anybus module transmits and receives data on the Fieldbus using the proper protocol. The SIFI is intended to be connected to other existing SNE modules in order to monitor the health and status of a transducer. The SIFI can also monitor aspects of its own health using an onboard watchdog timer and voltage monitors. The SIFI also has the hardware to drive a touchscreen LCD (liquid crystal display) unit for manual configuration and status monitoring.

Radial Basis Function Neural Network Application to Power System Restoration Studies

PubMed Central

Sadeghkhani, Iman; Ketabi, Abbas; Feuillet, Rene

2012-01-01

One of the most important issues in power system restoration is overvoltages caused by transformer switching. These overvoltages might damage some equipment and delay power system restoration. This paper presents a radial basis function neural network (RBFNN) to study transformer switching overvoltages. To achieve good generalization capability for developed RBFNN, equivalent parameters of the network are added to RBFNN inputs. The developed RBFNN is trained with the worst-case scenario of switching angle and remanent flux and tested for typical cases. The simulated results for a partial of 39-bus New England test system show that the proposed technique can estimate the peak values and duration of switching overvoltages with good accuracy. PMID:22792093

Comprehensive evaluation of impacts of distributed generation integration in distribution network

NASA Astrophysics Data System (ADS)

Peng, Sujiang; Zhou, Erbiao; Ji, Fengkun; Cao, Xinhui; Liu, Lingshuang; Liu, Zifa; Wang, Xuyang; Cai, Xiaoyu

2018-04-01

All Distributed generation (DG) as the supplement to renewable energy centralized utilization, is becoming the focus of development direction of renewable energy utilization. With the increasing proportion of DG in distribution network, the network power structure, power flow distribution, operation plans and protection are affected to some extent. According to the main impacts of DG, a comprehensive evaluation model of distributed network with DG is proposed in this paper. A comprehensive evaluation index system including 7 aspects, along with their corresponding index calculation method is established for quantitative analysis. The indices under different access capacity of DG in distribution network are calculated based on the IEEE RBTS-Bus 6 system and the evaluation result is calculated by analytic hierarchy process (AHP). The proposed model and method are verified effective and validity through case study.

Construct mine environment monitoring system based on wireless mesh network

NASA Astrophysics Data System (ADS)

Chen, Xin; Ge, Gengyu; Liu, Yinmei; Cheng, Aimin; Wu, Jun; Fu, Jun

2018-04-01

The system uses wireless Mesh network as a network transmission medium, and strive to establish an effective and reliable underground environment monitoring system. The system combines wireless network technology and embedded technology to monitor the internal data collected in the mine and send it to the processing center for analysis and environmental assessment. The system can be divided into two parts: the main control network module and the data acquisition terminal, and the SPI bus technology is used for mutual communication between them. Multi-channel acquisition and control interface design Data acquisition and control terminal in the analog signal acquisition module, digital signal acquisition module, and digital signal output module. The main control network module running Linux operating system, in which the transplant SPI driver, USB card driver and AODV routing protocol. As a result, the internal data collection and reporting of the mine are realized.

Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration : First Results Report

DOT National Transportation Integrated Search

2011-08-01

In response to the California Air Resources Board (CARB) rule for transit agencies in the state, five San Francisco Bay Area transit agencies have joined together to demonstrate the largest fleet of fuel cell buses in the United States. The Zero Emis...

Fuel Cell Buses in U.S. Transit Fleets: Current Status 2016

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eudy, Leslie; Post, Matthew; Jeffers, Matthew

This report, published annually, summarizes the progress of fuel cell electric bus development in the United States and discusses the achievements and challenges of introducing fuel cell propulsion in transit. The report provides a summary of results from evaluations performed by the National Renewable Energy Laboratory. Funding for this effort is provided by the U.S. Department of Energy's Fuel Cell Technologies Office within the Office of Energy Efficiency and Renewable Energy and by the U.S. Department of Transportation's Federal Transit Administration. The 2016 summary results primarily focus on the most recent year for each demonstration, from August 2015 through Julymore » 2016. The results for these buses account for more than 550,000 miles traveled and 59,500 hours of fuel cell power system operation. The primary results presented in the report are from three demonstrations of two different fuel-cell-dominant bus designs: Zero Emission Bay Area Demonstration Group led by Alameda-Contra Costa Transit District (AC Transit) in California; American Fuel Cell Bus Project at SunLine Transit Agency in California; and American Fuel Cell Bus Project at the University of California at Irvine.« less

Development and Commissioning Results of the Hybrid Sensor Bus Engineering Qualification Model

NASA Astrophysics Data System (ADS)

Hurni, Andreas; Putzer, Phillipp; Roner, Markus; Gurster, Markus; Hulsemeyer, Christian; Lemke, Norbert M. K.

2016-08-01

In order to reduce mass, AIT effort and overall costs of classical point-to-point wired temperature sensor harness on-board spacecraft OHB System AGhas introduced the Hybrid Sensor Bus (HSB) system which interrogates sensors connected in a bus architecture. To use the advantages of electrical as wellas of fiber-optical sensing technologies, HSB is designed as a modular measurement system interrogating digital sensors connected on electricalsensor buses based on I2C and fiber-optical sensor buses based on fiber Bragg grating (FBG) sensors inscribed in optical fibers. Fiber-optical sensor bus networks on-board satellites are well suited for temperature measurement due to low mass, electro-magnetic insensitivity and the capability to embed them inside structure parts. The lightweight FBG sensors inscribed in radiation tolerant fibers can reach every part of the satellite. HSB has been developed in the frame of the ESA ARTES program with European and German co- funding and will be verified as flight demonstrator on- board the German Heinrich Hertz satellite (H2Sat).In this paper the Engineering Qualification Model (EQM) development of HSB and first commissioning results are presented. For the HSB development requirements applicable for telecommunication satellite platforms have been considered. This includes an operation of at least 15 years in a geostationary orbit.In Q3/2016 the qualification test campaign is planned to be carried out. The HSB EQM undergoes a full qualification according to ECSS. The paper concludes with an outlook regarding this HSB flight demonstrator development and its in-orbit verification (IOV) on board H2Sat.

COM-BUS : A Southern California Subscription Bus Service

DOT National Transportation Integrated Search

1977-05-01

The evolution and operations of the COM-BUS Subscription Commuter Bus Service are documented. COM-BUS is a privately owned organization operating at a profit without any form of subsidy. COM-BUS serves approximately 2,000 commuters per day on 47 rout...

School buses, diesel emissions, and respiratory health.

PubMed

Beatty, Timothy K M; Shimshack, Jay P

2011-09-01

School buses contribute disproportionately to ambient air quality, pollute near schools and residential areas, and their emissions collect within passenger cabins. This paper examines the impact of school bus emissions reductions programs on health outcomes. A key contribution relative to the broader literature is that we examine localized pollution reduction programs at a fine level of aggregation. We find that school bus retrofits induced reductions in bronchitis, asthma, and pneumonia incidence for at-risk populations. Back of the envelope calculations suggest conservative benefit-cost ratios between 7:1 and 16:1. Copyright © 2011 Elsevier B.V. All rights reserved.

49 CFR 605.19 - Approval of school bus operations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Approval of school bus operations. 605.19 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.19 Approval of school bus operations. (a) The Administrator will consider the comments filed by private school bus...

49 CFR 605.18 - Comments by private school bus operators.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Comments by private school bus operators. 605.18... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS School Bus Agreements § 605.18 Comments by private school bus operators. Private school bus operators may file written comments on an applicant's...

49 CFR 605.18 - Comments by private school bus operators.

Code of Federal Regulations, 2010 CFR

2010-10-01

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

49 CFR 605.19 - Approval of school bus operations.

Code of Federal Regulations, 2010 CFR

2010-10-01

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

Modelling the protocol stack in NCS with deterministic and stochastic petri net

NASA Astrophysics Data System (ADS)

Hui, Chen; Chunjie, Zhou; Weifeng, Zhu

2011-06-01

Protocol stack is the basis of the networked control systems (NCS). Full or partial reconfiguration of protocol stack offers both optimised communication service and system performance. Nowadays, field testing is unrealistic to determine the performance of reconfigurable protocol stack; and the Petri net formal description technique offers the best combination of intuitive representation, tool support and analytical capabilities. Traditionally, separation between the different layers of the OSI model has been a common practice. Nevertheless, such a layered modelling analysis framework of protocol stack leads to the lack of global optimisation for protocol reconfiguration. In this article, we proposed a general modelling analysis framework for NCS based on the cross-layer concept, which is to establish an efficiency system scheduling model through abstracting the time constraint, the task interrelation, the processor and the bus sub-models from upper and lower layers (application, data link and physical layer). Cross-layer design can help to overcome the inadequacy of global optimisation based on information sharing between protocol layers. To illustrate the framework, we take controller area network (CAN) as a case study. The simulation results of deterministic and stochastic Petri-net (DSPN) model can help us adjust the message scheduling scheme and obtain better system performance.

A new bus lane on urban expressway with no-bay bus stop

NASA Astrophysics Data System (ADS)

Tian, Zhao; Jia, Limin

2016-01-01

The sharp increase in residents and vehicles causes heavy traffic pressure in many cities. To ease traffic congestion, it has been the common sense that we should develop public transit system. The priority of the bus appears particularly necessary with the rapid development of the public transport system. The bus lane is an important embodiment of the bus priority. Focusing on the problem of the unreasonable dedicated bus lane (DBL) under the lower ratio of buses, this paper proposed a new bus lane with limited physical length. And this bus lane can reduce the lane-changing conflict caused by the buses and cars running on roads without bus lanes. Based on the cellular automata (CA) traffic flow model and the lane-changing behavior of the vehicle including the optional lane-changing and the mandatory lane-changing, a three-lane traffic model with an isolated no-bay bus stop is proposed. The ordinary three-lane traffic without a bus lane and the cases of traffic with a DBL or the proposed bus lane are simulated, and the comparisons in the form of the fundamental diagrams are made among them. It is shown that the no-bay bus stop can act as a bottleneck on the traffic flow because of the mandatory lane-changing behavior. Under a certain ratio of the bus number to the total vehicles number, (1) the traffic with the proposed bus lane has less lane-changing conflict and can provide higher traffic capacity than the ordinary traffic without a bus lane, (2) compared with the DBL, the proposed bus lane is advantageous in easing congestion on the ordinary lanes when the traffic flow is high and can avoid unreasonable allocation of the road resources.

Shuttle bus services quality assessment Tangerang Selatan toward smart city

NASA Astrophysics Data System (ADS)

Fassa, Ferdinand; Sitorus, Fredy Jhon Philip; Adikesuma, Tri Nugraha

2017-11-01

Around the world, shuttle bus operation played the significant role to accommodate transportation for commuting bus passengers. Shuttle Bus services in cities are provided by various bus agencies with kinds of own specific purposes. For instance, at Tangerang Selatan, Indonesia, it was said that shuttle bus In Trans Bintaro is run and operated by private bus companies hire by Bintaro developer. The aim of this research is to identify factors of satisfaction of shuttle bus service in Kota Tangerang Selatan, Indonesia. Several factors are used to analyze sums of 20 parameters performance indicators of Shuttle Bus. A face to face interview using a questionnaire (N=200) was used to collect data on October and March 2017. Likert and diagram Cartesian were used to model the all the parameters. This research succeeded in finding some categories of Shuttle bus service attributes such as accessibility, comfort, and safety. Users agreed that eight indicators in shuttle bus have the excellent achievement, while three indicators on performance remain low and should receive more attention especially punctuality of the bus.

Slow Controls Using the Axiom M5235BCC

NASA Astrophysics Data System (ADS)

Hague, Tyler

2008-10-01

The Forward Vertex Detector group at PHENIX plans to adopt the Axiom M5235 Business Card Controller for use as slow controls. It is also being evaluated for slow controls on FermiLab e906. This controller features the Freescale MCF5235 microprocessor. It also has three parallel buses, these being the MCU port, BUS port, and enhanced Time Processing Unit (eTPU) port. The BUS port uses a chip select module with three external chip selects to communicate with peripherals. This will be used to communicate with and configure Field Programmable Gate Arrays (FPGAs). The controller also has an Ethernet port which can use several different protocols such as TCP and UDP. This will be used to transfer files with computers on a network. The M5235 Business Card Controller will be placed in a VME crate along with VME card and a Spartan-3 FPGA.

Reconfiguration of Smart Distribution Network in the Presence of Renewable DG’s Using GWO Algorithm

NASA Astrophysics Data System (ADS)

Siavash, M.; Pfeifer, C.; Rahiminejad, A.; Vahidi, B.

2017-08-01

In this paper, the optimal reconfiguration of smart distribution system is performed with the aim of active power loss reduction and voltage stability improvement. The distribution network is considered equipped with wind turbines and solar cells as Renewable DG’s (RDG’s). Because of the presence of smart metering devices, the network state is known accurately at any moment. Based on the network conditions (the amount of load and generation of RDG’s), the optimal configuration of the network is obtained. The optimization problem is solved using a recently introduced method known as Grey Wolf Optimizer (GWO). The proposed approach is applied on 69-bus radial test system and the results of the GWO are compared to those of Particle Swarm Optimization (PSO), and Genetic Algorithm (GA). The results show the effectiveness of the proposed approach and the selected optimization method.

Optical interconnection network for parallel access to multi-rank memory in future computing systems.

PubMed

Wang, Kang; Gu, Huaxi; Yang, Yintang; Wang, Kun

2015-08-10

With the number of cores increasing, there is an emerging need for a high-bandwidth low-latency interconnection network, serving core-to-memory communication. In this paper, aiming at the goal of simultaneous access to multi-rank memory, we propose an optical interconnection network for core-to-memory communication. In the proposed network, the wavelength usage is delicately arranged so that cores can communicate with different ranks at the same time and broadcast for flow control can be achieved. A distributed memory controller architecture that works in a pipeline mode is also designed for efficient optical communication and transaction address processes. The scaling method and wavelength assignment for the proposed network are investigated. Compared with traditional electronic bus-based core-to-memory communication, the simulation results based on the PARSEC benchmark show that the bandwidth enhancement and latency reduction are apparent.

Serial network simplifies the design of multiple microcomputer systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Folkes, D.

1981-01-01

Recently there has been a lot of interest in developing network communication schemes for carrying digital data between locally distributed computing stations. Many of these schemes have focused on distributed networking techniques for data processing applications. These applications suggest the use of a serial, multipoint bus, where a number of remote intelligent units act as slaves to a central or host computer. Each slave would be serially addressable from the host and would perform required operations upon being addressed by the host. Based on an MK3873 single-chip microcomputer, the SCU 20 is designed to be such a remote slave device.more » The capabilities of the SCU 20 and its use in systems applications are examined.« less

78 FR 17995 - Agency Information Collection Activity Under OMB Review

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-25

... collections: 49 U.S.C. Section 5337--State of Good Repair Program 49 U.S.C. Section 5339--Bus and Bus... on a quarterly basis. The information submitted ensures FTA's compliance with applicable federal laws. Title: 49 U.S.C. Section 5339--Bus and Bus Facilities Program. Abstract: 49 U.S.C. 5339--Bus and Bus...

Robust Distribution Network Reconfiguration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Changhyeok; Liu, Cong; Mehrotra, Sanjay

2015-03-01

We propose a two-stage robust optimization model for the distribution network reconfiguration problem with load uncertainty. The first-stage decision is to configure the radial distribution network and the second-stage decision is to find the optimal a/c power flow of the reconfigured network for given demand realization. We solve the two-stage robust model by using a column-and-constraint generation algorithm, where the master problem and subproblem are formulated as mixed-integer second-order cone programs. Computational results for 16, 33, 70, and 94-bus test cases are reported. We find that the configuration from the robust model does not compromise much the power loss undermore » the nominal load scenario compared to the configuration from the deterministic model, yet it provides the reliability of the distribution system for all scenarios in the uncertainty set.« less

Advanced Intelligent System Application to Load Forecasting and Control for Hybrid Electric Bus

NASA Technical Reports Server (NTRS)

Momoh, James; Chattopadhyay, Deb; Elfayoumy, Mahmoud

1996-01-01

The primary motivation for this research emanates from providing a decision support system to the electric bus operators in the municipal and urban localities which will guide the operators to maintain an optimal compromise among the noise level, pollution level, fuel usage etc. This study is backed up by our previous studies on study of battery characteristics, permanent magnet DC motor studies and electric traction motor size studies completed in the first year. The operator of the Hybrid Electric Car must determine optimal power management schedule to meet a given load demand for different weather and road conditions. The decision support system for the bus operator comprises three sub-tasks viz. forecast of the electrical load for the route to be traversed divided into specified time periods (few minutes); deriving an optimal 'plan' or 'preschedule' based on the load forecast for the entire time-horizon (i.e., for all time periods) ahead of time; and finally employing corrective control action to monitor and modify the optimal plan in real-time. A fully connected artificial neural network (ANN) model is developed for forecasting the kW requirement for hybrid electric bus based on inputs like climatic conditions, passenger load, road inclination, etc. The ANN model is trained using back-propagation algorithm employing improved optimization techniques like projected Lagrangian technique. The pre-scheduler is based on a Goal-Programming (GP) optimization model with noise, pollution and fuel usage as the three objectives. GP has the capability of analyzing the trade-off among the conflicting objectives and arriving at the optimal activity levels, e.g., throttle settings. The corrective control action or the third sub-task is formulated as an optimal control model with inputs from the real-time data base as well as the GP model to minimize the error (or deviation) from the optimal plan. These three activities linked with the ANN forecaster proving the output to the GP model which in turn produces the pre-schedule of the optimal control model. Some preliminary results based on a hypothetical test case will be presented for the load forecasting module. The computer codes for the three modules will be made available fe adoption by bus operating agencies. Sample results will be provided using these models. The software will be a useful tool for supporting the control systems for the Electric Bus project of NASA.

Analysis of movable bus stop boarding and alighting areas : [summary].

DOT National Transportation Integrated Search

2013-05-01

Floridas transit ridership comprises persons from : varying demographic backgrounds, including : those with disabilities. An important goal for the : Florida Deaprtment of Transportation (FDOT) : and Florida transit agencies is to ensure that all ...

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

DOEpatents

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

1991-01-15

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

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

DOEpatents

Atac, Robert; Fischler, Mark S.; Husby, Donald E.

1991-01-01

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

Wireless Sensor Buoys for Perimeter Security of Military Vessels and Seabases

DTIC Science & Technology

2015-12-01

however, additional sensors utilizing modern technology and a self -forming, as well as self - healing , network could further diminish attacks against...Space SSDF Ship’s Self -Defense Force UAV Unmanned Aerial Vehicle UGS Unattended Ground Sensor USB Universal Serial Bus USMC United States Marine...conditions may delay their reaction resulting in the attacking surface craft entering into a critically close position. The Ship’s Self -Defense

Implementation of Particle Swarm Optimization Method for Voltage Stability Analysis in 150 kV Sub System Grati – Paiton East Java

NASA Astrophysics Data System (ADS)

Kusumaningtyas, A. B.; Hidayat, M. N.; Ronilaya, F.

2018-04-01

Based on the data from State Electric Company on 15 January 2013, the undistributed power in the 150 kV sub system Grati-Paiton Region IV, that consist of 26 bus 150 kV and 2 bus generation 500 kV system, was recorded 3.286,00 MW. At the same time, the frequency of the system was down to 49 Hz. This lead to a deficit generation and unstable voltage condition in the system. Fast Voltage Stability Index (FVSI) method is used in this research to analyze the voltage stability of the buses. For buses with unstable voltage condition, reactive power will be injected through capacitor installation. The site where the capacitor will be installed is determined using the Fast Voltage Stability Index (FVSI) method while the size of the capacitor is determined using the Particle Swarm Optimization (PSO) method. The PSO method has been applied in some researches, such as to determine optimal placement and sizing in radial distribution network as well as in transmission network.. In this research, the PSO method is used to find the Qloss of an interconnection transmission system, which in turn, the value of the Qloss is used to determine the capacitance of the capacitor needed by the system.

Traveling by Bus Instead of Car on Urban Major Roads: Safety Benefits for Vehicle Occupants, Pedestrians, and Cyclists.

PubMed

Morency, Patrick; Strauss, Jillian; Pépin, Félix; Tessier, François; Grondines, Jocelyn

2018-04-01

Some studies have estimated fatality and injury rates for bus occupants, but data was aggregated at the country level and made no distinction between bus types. Also, injured pedestrians and cyclists, as a result of bus travel, were overlooked. We compared injury rates for car and city bus occupants on specific urban major roads, as well as the cyclist and pedestrian injuries associated with car and bus travel. We selected ten bus routes along major urban arterials (in Montreal, Canada). Passenger-kilometers traveled were estimated from vehicle counts at intersections (2002-2010) and from bus passenger counts (2008). Police accident reports (2001-2010) provided injury data for all modes. Injury rates associated with car and bus travel were calculated for vehicle occupants, pedestrians, and cyclists. Injury rate ratios were also computed. The safety benefits of bus travel, defined as the number of vehicle occupant, cyclist, and pedestrian injuries saved, were estimated for each route. Overall, for all ten routes, the ratio between car and bus occupant injury rates is 3.7 (95% CI [3.4, 4.0]). The rates of pedestrian and cyclist injuries per hundred million passenger-kilometers are also significantly greater for car travel than that for bus travel: 4.1 (95% CI [3.5, 4.9]) times greater for pedestrian injuries; 5.3 (95% CI [3.8, 7.6]) times greater for cyclist injuries. Similar results were observed for fatally and severely injured vehicle occupants, cyclists, and pedestrians. At the route level, the safety benefits of bus travel increase with the difference in injury rate associated with car and bus travel but also with the amount of passenger-kilometers by bus. Results show that city bus is a safer mode than car, for vehicle occupants but also for cyclists and pedestrians traveling along these bus routes. The safety benefits of bus travel greatly vary across urban routes; this spatial variation is most likely linked to environmental factors. Understanding the safety benefits of public transit for specific transport routes is likely to provide valuable information for mobilizing city and transportation planners.

A new balancing three level three dimensional space vector modulation strategy for three level neutral point clamped four leg inverter based shunt active power filter controlling by nonlinear back stepping controllers.

PubMed

Chebabhi, Ali; Fellah, Mohammed Karim; Kessal, Abdelhalim; Benkhoris, Mohamed F

2016-07-01

In this paper is proposed a new balancing three-level three dimensional space vector modulation (B3L-3DSVM) strategy which uses a redundant voltage vectors to realize precise control and high-performance for a three phase three-level four-leg neutral point clamped (NPC) inverter based Shunt Active Power Filter (SAPF) for eliminate the source currents harmonics, reduce the magnitude of neutral wire current (eliminate the zero-sequence current produced by single-phase nonlinear loads), and to compensate the reactive power in the three-phase four-wire electrical networks. This strategy is proposed in order to gate switching pulses generation, dc bus voltage capacitors balancing (conserve equal voltage of the two dc bus capacitors), and to switching frequency reduced and fixed of inverter switches in same times. A Nonlinear Back Stepping Controllers (NBSC) are used for regulated the dc bus voltage capacitors and the SAPF injected currents to robustness, stabilizing the system and to improve the response and to eliminate the overshoot and undershoot of traditional PI (Proportional-Integral). Conventional three-level three dimensional space vector modulation (C3L-3DSVM) and B3L-3DSVM are calculated and compared in terms of error between the two dc bus voltage capacitors, SAPF output voltages and THDv, THDi of source currents, magnitude of source neutral wire current, and the reactive power compensation under unbalanced single phase nonlinear loads. The success, robustness, and the effectiveness of the proposed control strategies are demonstrated through simulation using Sim Power Systems and S-Function of MATLAB/SIMULINK. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Propulsion system for a motor vehicle using a bidirectional energy converter

DOEpatents

Tamor, Michael Alan; Gale, Allan Roy

1999-01-01

A motor vehicle propulsion system includes an electrical energy source and a traction motor coupled to receive electrical energy from the electrical energy source. The system also has a first bus provided electrical energy by the electrical energy source and a second bus of relatively lower voltage than the first bus. In addition, the system includes an electrically-driven source of reaction gas for the electrical energy source, the source of reaction gas coupled to receive electrical energy from the first bus. Also, the system has an electrical storage device coupled to the second bus for storing electrical energy at the lower voltage. The system also includes a bidirectional energy converter coupled to convert electrical energy from the first bus to the second bus and from the second bus to the first bus.

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

NASA Astrophysics Data System (ADS)

Yamauchi, Hiroyuki; Akamatsu, Hironori; Fujita, Tsutomu

1995-04-01

An asymptotically zero power charge recycling bus (CRB) architecture, featuring virtual stacking of the individual bus-capacitance into a series configuration between supply voltage and ground, has been proposed. This CRB architecture makes it possible to reduce not only each bus-swing but also a total equivalent bus-capacitance of the ultramultibit buses running in parallel. The voltage swing of each bus is given by the recycled charge-supplying from the upper adjacent bus capacitance, instead of the power line. The dramatical power reduction was verified by the simulated and measured data. According to these data, the ultrahigh data rate of 25.6 Gb/s can be achieved while maintaining the power dissipation to be less than 100 mW, which corresponds to less than 10% that of the previously reported 0.9 V suppressed bus-swing scheme, at V(sub cc) = 3.6 V for the bus width of 512 b with the bus-capacitance of 14 pF per bit operating at 50 MHz.

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

PubMed Central

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

2015-01-01

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

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

PubMed

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

2015-01-01

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

A Real-Time Decision Support System for Voltage Collapse Avoidance in Power Supply Networks

NASA Astrophysics Data System (ADS)

Chang, Chen-Sung

This paper presents a real-time decision support system (RDSS) based on artificial intelligence (AI) for voltage collapse avoidance (VCA) in power supply networks. The RDSS scheme employs a fuzzy hyperrectangular composite neural network (FHRCNN) to carry out voltage risk identification (VRI). In the event that a threat to the security of the power supply network is detected, an evolutionary programming (EP)-based algorithm is triggered to determine the operational settings required to restore the power supply network to a secure condition. The effectiveness of the RDSS methodology is demonstrated through its application to the American Electric Power Provider System (AEP, 30-bus system) under various heavy load conditions and contingency scenarios. In general, the numerical results confirm the ability of the RDSS scheme to minimize the risk of voltage collapse in power supply networks. In other words, RDSS provides Power Provider Enterprises (PPEs) with a viable tool for performing on-line voltage risk assessment and power system security enhancement functions.

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

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-30

... public agencies, private companies engaged in public transportation, or private non-profit organizations... public transportation bus fleet, infrastructure, and equipment in a state of good repair. Grantees... DEPARTMENT OF TRANSPORTATION Federal Transit Administration State of Good Repair Bus and Bus...

49 CFR 655.4 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) Carrying a firearm for security purposes. Vehicle means a bus, electric bus, van, automobile, rail car... involved is a bus, electric bus, van, or automobile, one or more vehicles (including non-FTA funded... the public transportation vehicle involved is a rail car, trolley car, trolley bus, or vessel, the...

49 CFR 655.4 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Carrying a firearm for security purposes. Vehicle means a bus, electric bus, van, automobile, rail car... involved is a bus, electric bus, van, or automobile, one or more vehicles (including non-FTA funded... the public transportation vehicle involved is a rail car, trolley car, trolley bus, or vessel, the...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xiaohu; Shi, Di; Wang, Zhiwei

Shunt FACTS devices, such as, a Static Var Compensator (SVC), are capable of providing local reactive power compensation. They are widely used in the network to reduce the real power loss and improve the voltage profile. This paper proposes a planning model based on mixed integer conic programming (MICP) to optimally allocate SVCs in the transmission network considering load uncertainty. The load uncertainties are represented by a number of scenarios. Reformulation and linearization techniques are utilized to transform the original non-convex model into a convex second order cone programming (SOCP) model. Numerical case studies based on the IEEE 30-bus systemmore » demonstrate the effectiveness of the proposed planning model.« less

Woods Hole Science Aquarium: VISITING

Science.gov Websites

access to the aquarium's back-up area and touch tank is available via a ramp at the rear of the aquarium . Directions from Directions from Boston Directions from Providence Coming by bus The Woods Hole Science

Dispersion of CNG Following a High-Pressure Release

DOT National Transportation Integrated Search

1996-05-01

This report discusses the results of tests to determine the dispersive behavior of compressed natural gas (CNG) when released in enclosed areas such as transit bus facility, and presents the Volpe National Transportation Systems Center's (VNTSC) conc...

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

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-07

... that are public agencies, private companies engaged in public transportation, or private non-profit... Table 1 will provide funds to help maintain the nation's public transportation bus fleet, infrastructure... DEPARTMENT OF TRANSPORTATION Federal Transit Administration State of Good Repair Bus and Bus...

Bus Training Handbook.

ERIC Educational Resources Information Center

Dorny, Audrea; Cole, ChiKay

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

49 CFR 655.4 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) Carrying a firearm for security purposes. Vehicle means a bus, electric bus, van, automobile, rail car... involved is a bus, electric bus, van, or automobile, one or more vehicles (including non-FTA funded... the mass transit vehicle involved is a rail car, trolley car, trolley bus, or vessel, the mass transit...

49 CFR 655.4 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) Carrying a firearm for security purposes. Vehicle means a bus, electric bus, van, automobile, rail car... involved is a bus, electric bus, van, or automobile, one or more vehicles (including non-FTA funded... the mass transit vehicle involved is a rail car, trolley car, trolley bus, or vessel, the mass transit...

49 CFR 655.4 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Carrying a firearm for security purposes. Vehicle means a bus, electric bus, van, automobile, rail car... involved is a bus, electric bus, van, or automobile, one or more vehicles (including non-FTA funded... the mass transit vehicle involved is a rail car, trolley car, trolley bus, or vessel, the mass transit...

Forecast analysis of optical waveguide bus performance

NASA Technical Reports Server (NTRS)

Ledesma, R.; Rourke, M. D.

1979-01-01

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

Massachusetts Fuel Cell Bus Project: Demonstrating a Total Transit Solution for Fuel Cell Electric Buses in Boston

DOE Office of Scientific and Technical Information (OSTI.GOV)

The Federal Transit Administration's National Fuel Cell Bus Program focuses on developing commercially viable fuel cell bus technologies. Nuvera is leading the Massachusetts Fuel Cell Bus project to demonstrate a complete transit solution for fuel cell electric buses that includes one bus and an on-site hydrogen generation station for the Massachusetts Bay Transportation Authority (MBTA). A team consisting of ElDorado National, BAE Systems, and Ballard Power Systems built the fuel cell electric bus, and Nuvera is providing its PowerTap on-site hydrogen generator to provide fuel for the bus.

Electrical system architecture

DOEpatents

Algrain, Marcelo C [Peoria, IL; Johnson, Kris W [Washington, IL; Akasam, Sivaprasad [Peoria, IL; Hoff, Brian D [East Peoria, IL

2008-07-15

An electrical system for a vehicle includes a first power source generating a first voltage level, the first power source being in electrical communication with a first bus. A second power source generates a second voltage level greater than the first voltage level, the second power source being in electrical communication with a second bus. A starter generator may be configured to provide power to at least one of the first bus and the second bus, and at least one additional power source may be configured to provide power to at least one of the first bus and the second bus. The electrical system also includes at least one power consumer in electrical communication with the first bus and at least one power consumer in electrical communication with the second bus.

School bus and children's traffic safety.

PubMed

Pan, Shu-ming; Hargarten, Stephen; Zhu, Shan-kuan

2007-08-01

There is no safer way to transport a child than a school bus. Fatal crashes involving occupants are extremely rare events in the US. In recent years, school bus transportation began to develop in China. We want to bring advanced experience on school bus safety in Western countries such as the US to developing countries. We searched the papers related to school bus safety from Medline, Chinese Scientific Journals Database and the Web of the National Highway Traffic Safety Administration (NHTSA). There were only 9 papers related to school bus safety, which showed that higher levels of safety standards on school buses, school bus-related transportation and environmental laws and injury prevention were the primary reasons for the desired outcome. Few school bus is related to deaths and injuries in the developed countries. The developing countries should make strict environmental laws and standards on school bus safety to prevent children's injury and death.

Modeling the effect of bus stops on capacity of curb lane

NASA Astrophysics Data System (ADS)

Luo, Qingyu; Zheng, Tianyao; Wu, Wenjing; Jia, Hongfei; Li, Jin

With the increase of buses and bus lines, a negative effect on road section capacity is made by the prolonged delay and queuing time at bus stops. However, existing methods of measuring the negative effect pay little attention to different bus stop types in the curb lanes. This paper uses Gap theory and Queuing theory to build models for effect-time and potential capacity in different conditions, including curbside bus stops, bus bays with overflow and bus bays without overflow. In order to make the effect-time models accurate and reliable, two types of probabilities are introduced. One is the probability that the dwell time is less than the headway of curb lane at curbside bus stops; the other is the overflow probability at bus bays. Based on the fundamental road capacity model and effect-time models, potential capacity models of curb lane are designed. The new models are calibrated by the survey data from Changchun City, and verified by the simulation software of VISSIM. Furthermore, with different arrival rates of vehicles, the setting conditions of bus stops are researched. Results show that the potential capacity models have high precision. They can offer a reference for recognizing the effect of bus stops on the capacity of curb lane, which can provide a basis for planning, design and management of urban roads and bus stops.

49 CFR 393.62 - Emergency exits for buses.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (including a school bus used in interstate commerce for non-school bus operations) with a GVWR of more than 4... manufacture. (2) Each bus (including a school bus used in interstate commerce for non-school bus operations... NECESSARY FOR SAFE OPERATION Glazing and Window Construction § 393.62 Emergency exits for buses. (a) Buses...

49 CFR 393.62 - Emergency exits for buses.

Code of Federal Regulations, 2013 CFR

2013-10-01

... (including a school bus used in interstate commerce for non-school bus operations) with a GVWR of more than 4... manufacture. (2) Each bus (including a school bus used in interstate commerce for non-school bus operations... NECESSARY FOR SAFE OPERATION Glazing and Window Construction § 393.62 Emergency exits for buses. (a) Buses...

49 CFR 393.62 - Emergency exits for buses.

Code of Federal Regulations, 2014 CFR

2014-10-01

... (including a school bus used in interstate commerce for non-school bus operations) with a GVWR of more than 4... manufacture. (2) Each bus (including a school bus used in interstate commerce for non-school bus operations... NECESSARY FOR SAFE OPERATION Glazing and Window Construction § 393.62 Emergency exits for buses. (a) Buses...

49 CFR 393.62 - Emergency exits for buses.

Code of Federal Regulations, 2012 CFR

2012-10-01

... (including a school bus used in interstate commerce for non-school bus operations) with a GVWR of more than 4... manufacture. (2) Each bus (including a school bus used in interstate commerce for non-school bus operations... NECESSARY FOR SAFE OPERATION Glazing and Window Construction § 393.62 Emergency exits for buses. (a) Buses...

Electric School Bus Testing | Transportation Research | NREL

Science.gov Websites

Electric School Bus Evaluation Electric School Bus Evaluation Photo of children boarding school bus . NREL is evaluating the performance of electric and conventional school buses operated by two California school districts. Photo courtesy of School Bus Fleet Magazine NREL is evaluating the in-service

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

ERIC Educational Resources Information Center

Wisconsin State Dept. of Transportation, Madison.

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

Multirate control with incomplete information over Profibus-DP network

NASA Astrophysics Data System (ADS)

Salt, J.; Casanova, V.; Cuenca, A.; Pizá, R.

2014-07-01

When a process field bus-decentralized peripherals (Profibus-DP) network is used in an industrial environment, a deterministic behaviour is usually claimed. However, due to some concerns such as bandwidth limitations, lack of synchronisation among different clocks and existence of time-varying delays, a more complex problem must be faced. This problem implies the transmission of irregular and, even, random sequences of incomplete information. The main consequence of this issue is the appearance of different sampling periods at different network devices. In this paper, this aspect is checked by means of a detailed Profibus-DP timescale study. In addition, in order to deal with the different periods, a delay-dependent dual-rate proportional-integral-derivative control is introduced. Stability for the proposed control system is analysed in terms of linear matrix inequalities.

29 CFR 1982.101 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... include school buses, charter, or intercity bus transportation or intercity passenger rail transportation... transportation systems that connect metropolitan areas, without regard to whether those systems use new technologies not associated with traditional railroads, but does not include rapid transit operations in an...

An Efficient Method of Sharing Mass Spatio-Temporal Trajectory Data Based on Cloudera Impala for Traffic Distribution Mapping in an Urban City

PubMed Central

Zhou, Lianjie; Chen, Nengcheng; Yuan, Sai; Chen, Zeqiang

2016-01-01

The efficient sharing of spatio-temporal trajectory data is important to understand traffic congestion in mass data. However, the data volumes of bus networks in urban cities are growing rapidly, reaching daily volumes of one hundred million datapoints. Accessing and retrieving mass spatio-temporal trajectory data in any field is hard and inefficient due to limited computational capabilities and incomplete data organization mechanisms. Therefore, we propose an optimized and efficient spatio-temporal trajectory data retrieval method based on the Cloudera Impala query engine, called ESTRI, to enhance the efficiency of mass data sharing. As an excellent query tool for mass data, Impala can be applied for mass spatio-temporal trajectory data sharing. In ESTRI we extend the spatio-temporal trajectory data retrieval function of Impala and design a suitable data partitioning method. In our experiments, the Taiyuan BeiDou (BD) bus network is selected, containing 2300 buses with BD positioning sensors, producing 20 million records every day, resulting in two difficulties as described in the Introduction section. In addition, ESTRI and MongoDB are applied in experiments. The experiments show that ESTRI achieves the most efficient data retrieval compared to retrieval using MongoDB for data volumes of fifty million, one hundred million, one hundred and fifty million, and two hundred million. The performance of ESTRI is approximately seven times higher than that of MongoDB. The experiments show that ESTRI is an effective method for retrieving mass spatio-temporal trajectory data. Finally, bus distribution mapping in Taiyuan city is achieved, describing the buses density in different regions at different times throughout the day, which can be applied in future studies of transport, such as traffic scheduling, traffic planning and traffic behavior management in intelligent public transportation systems. PMID:27801869

Real-time bus location monitoring using Arduino

NASA Astrophysics Data System (ADS)

Ibrahim, Mohammad Y. M.; Audah, Lukman

2017-09-01

The Internet of Things (IoT) is the network of objects, such as a vehicles, mobile devices, and buildings that have electronic components, software, and network connectivity that enable them to collect data, run commands, and be controlled through the Internet. Controlling physical items from the Internet will increase efficiency and save time. The growing number of devices used by people increases the practicality of having IoT devices on the market. The IoT is also an opportunity to develop products that can save money and time and increase work efficiency. Initially, they need more efficiency for real-time bus location systems, especially in university campuses. This system can easily find the accurate locations of and distances between each bus stop and the estimated time to reach a new location. This system has been separated into two parts, which are the hardware and the software. The hardware parts are the Arduino Uno and the Global Positioning System (GPS), while Google Earth and GpsGate are the software parts. The GPS continuously takes input data from the satellite and stores the latitude and longitude values in the Arduino Uno. If we want to track the vehicle, we need to send the longitude and latitude as a message to the Google Earth software to convert these into maps for navigation. Once the Arduino Uno is activated, it takes the last received latitude and longitude positions' values from GpsGate and sends a message to Google Earth. Once the message has been sent to Google Earth, the current location will be shown, and navigation will be activated automatically. Then it will be broadcast using ManyCam, Google+ Hangouts, and YouTube, as well as Facebook, and appear to users. The additional features use Google Forms for determining problems faced by students, who can also take immediate action against the responsible department. Then after several successful simulations, the results will be shown in real time on a map.

Internet-Protocol-Based Satellite Bus Architecture Designed

NASA Technical Reports Server (NTRS)

Slywczak, Richard A.

2004-01-01

NASA is designing future complex satellite missions ranging from single satellites and constellations to space networks and sensor webs. These missions require more interoperability, autonomy, and coordination than previous missions; in addition, a desire exists to have scientists retrieve data directly from the satellite rather than a central distribution source. To meet these goals, NASA has been studying the possibility of extending the Transmission Control Protocol/Internet Protocol (TCP/IP) suite for spacebased applications.

Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (76th, Kansas City, Missouri, August 11-14, l993). Part VII: Politics and Mass Media.

ERIC Educational Resources Information Center

Association for Education in Journalism and Mass Communication.

The Politics and Mass Media section of this collection of conference presentations contains the following 13 papers: "The 1992 Presidential Debates: A Cognigraphic View" (Richard F. Carter and Keith R. Stamm); "Moving to the Front of the Bus?: Network Coverage of the Invisible Primaries during the 1988 and 1992 Elections"…

Investigation on application of genetic algorithms to optimal reactive power dispatch of power systems

NASA Astrophysics Data System (ADS)

Wu, Q. H.; Ma, J. T.

1993-09-01

A primary investigation into application of genetic algorithms in optimal reactive power dispatch and voltage control is presented. The application was achieved, based on (the United Kingdom) National Grid 48 bus network model, using a novel genetic search approach. Simulation results, compared with that obtained using nonlinear programming methods, are included to show the potential of applications of the genetic search methodology in power system economical and secure operations.

Advanced Teleprocessing Systems

DTIC Science & Technology

1981-09-30

Univur’iiy of Califtri ABSTRACT The network technologies developed over the past decade. due lagly to incredibe advances in integrated chip production. have...seo the stage for an enormous DP revolution the impact of which will soon be felt in the businms community and in the home and consumer markets . We have...most common of (which has already begun). At the top of this the bus architectures is perhaps the well- chain we see the integrated chip from which

Ny-Alesund Geodetic Observatory

NASA Technical Reports Server (NTRS)

Sieber, Moritz

2013-01-01

In 2012 the 20-m telescope at Ny-Alesund, Svalbard, operated by the Norwegian Mapping Authority (NMA), took part in 163 out of 168 scheduled sessions of the IVS program. Since spring, all data was transferred by network, and the receiver monitoring computer was replaced by a bus-coupler. In autumn, the NMA received building permission for a new observatory from the Governor of Svalbard. The bidding process and first construction work for the infrastructure will start in 2013.

Real life testing of a Hybrid PEM Fuel Cell Bus

NASA Astrophysics Data System (ADS)

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

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

TMS communications software. Volume 2: Bus interface unit

NASA Technical Reports Server (NTRS)

Gregor, P. J.

1979-01-01

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

Fault-tolerant processing system

NASA Technical Reports Server (NTRS)

Palumbo, Daniel L. (Inventor)

1996-01-01

A fault-tolerant, fiber optic interconnect, or backplane, which serves as a via for data transfer between modules. Fault tolerance algorithms are embedded in the backplane by dividing the backplane into a read bus and a write bus and placing a redundancy management unit (RMU) between the read bus and the write bus so that all data transmitted by the write bus is subjected to the fault tolerance algorithms before the data is passed for distribution to the read bus. The RMU provides both backplane control and fault tolerance.

Neighborhood-based tobacco advertising targeting adolescents.

PubMed Central

Ammerman, S D; Nolden, M

1995-01-01

Adolescent tobacco use remains a serious problem, and adolescents may be particularly receptive to the glamorous images tobacco companies use in advertisements. A relatively new form of neighborhood-based outdoor advertising, the illuminated bus-stop-shelter billboard, was studied to determine tobacco companies' use of this medium. We hypothesized that in 2 distinct San Francisco, California, neighborhoods, 1 predominantly white and the other mostly Latino, we would find a predominance of tobacco advertising on these billboards in both neighborhoods, that tobacco advertisements would be more prevalent in the minority Latino neighborhood, and that tobacco advertising would target adolescents in both neighborhoods. Each bus-stop-shelter billboard advertisement in the study areas from April 1992 to March 1993 was recorded. The type and frequency of products advertised and qualitative content of tobacco advertisements were analyzed. Adolescents' possible exposure to these advertisements was noted. Our main outcome measures were the percentage of tobacco advertising, possible adolescent exposure to this advertising, and themes of the tobacco advertisements. About 10% of all bus-stop-shelter billboard advertisements in each area promoted tobacco use. Possible exposures to these advertisements were greater in the Latino neighborhood because of a greater adolescent population. Qualitative analyses of tobacco advertisements suggested that adolescents are the primary targets. We urge physicians and educators to explicitly address this form of tobacco advertising, and we urge a ban on neighborhood-based tobacco advertising. PMID:7618311

Neighborhood-based tobacco advertising targeting adolescents.

PubMed

Ammerman, S D; Nolden, M

1995-06-01

Adolescent tobacco use remains a serious problem, and adolescents may be particularly receptive to the glamorous images tobacco companies use in advertisements. A relatively new form of neighborhood-based outdoor advertising, the illuminated bus-stop-shelter billboard, was studied to determine tobacco companies' use of this medium. We hypothesized that in 2 distinct San Francisco, California, neighborhoods, 1 predominantly white and the other mostly Latino, we would find a predominance of tobacco advertising on these billboards in both neighborhoods, that tobacco advertisements would be more prevalent in the minority Latino neighborhood, and that tobacco advertising would target adolescents in both neighborhoods. Each bus-stop-shelter billboard advertisement in the study areas from April 1992 to March 1993 was recorded. The type and frequency of products advertised and qualitative content of tobacco advertisements were analyzed. Adolescents' possible exposure to these advertisements was noted. Our main outcome measures were the percentage of tobacco advertising, possible adolescent exposure to this advertising, and themes of the tobacco advertisements. About 10% of all bus-stop-shelter billboard advertisements in each area promoted tobacco use. Possible exposures to these advertisements were greater in the Latino neighborhood because of a greater adolescent population. Qualitative analyses of tobacco advertisements suggested that adolescents are the primary targets. We urge physicians and educators to explicitly address this form of tobacco advertising, and we urge a ban on neighborhood-based tobacco advertising.

Analysis of real-time variables affecting children's exposure to diesel-related pollutants during school bus commutes in Los Angeles

NASA Astrophysics Data System (ADS)

Sabin, Lisa D.; Kozawa, Kathleen; Behrentz, Eduardo; Winer, Arthur M.; Fitz, Dennis R.; Pankratz, David V.; Colome, Steven D.; Fruin, Scott A.

Variables affecting children's exposure during school bus commutes were investigated using real-time measurements of black carbon (BC), particle-bound polycyclic aromatic hydrocarbons (PB-PAH) and nitrogen dioxide (NO 2) inside 3 conventional diesel school buses, a particle trap-outfitted (TO) diesel school bus and a compressed natural gas (CNG) school bus, while traveling along an urban Los Angeles Unified School District bus route. A video camera was mounted at the front of each bus to record roadway conditions ahead of the bus during each commute. The videotapes from 12 commutes, in conjunction with pollutant concentration time series, were used to determine the influence of variables such as vehicles being followed, bus type and roadway type on pollutant concentrations inside the bus. For all buses tested, the highest concentrations of BC, PB-PAH and NO 2 were observed when following a diesel school bus, especially if that bus was emitting visible exhaust. This result was important because other diesel school buses were responsible for the majority of the diesel vehicle encounters, primarily due to caravanning with each other when leaving a school at the same time. Compared with following a gasoline vehicle or no target, following a smoky diesel school bus yielded BC and PB-PAH concentrations inside the cabin 8 and 11 times higher, respectively, with windows open, and ˜1.8 times higher for both pollutants with windows closed. When other diesel vehicles were not present, pollutant concentrations were highest inside the conventional diesel buses and lowest inside the CNG bus, while the TO diesel bus exhibited intermediate concentrations. Differences in pollutant concentrations between buses were most pronounced with the bus windows closed, and were attributed to a combination of higher concentrations in the exhaust and higher exhaust gas intrusion rates for the conventional diesel buses. Conventional diesel school buses can have a double exposure impact on commuting children: first, exposures to the exhaust from other nearby diesel school buses and, second, exposure to the bus's own exhaust through "self-pollution".

Exposure to ultrafine particles and PM 2.5 in four Sydney transport modes

NASA Astrophysics Data System (ADS)

Knibbs, Luke D.; de Dear, Richard J.

2010-08-01

Concentrations of ultrafine (<0.1 μm) particles (UFPs) and PM 2.5 (<2.5 μm) were measured whilst commuting along a similar route by train, bus, ferry and automobile in Sydney, Australia. One trip on each transport mode was undertaken during both morning and evening peak hours throughout a working week, for a total of 40 trips. Analyses comprised one-way ANOVA to compare overall (i.e. all trips combined) geometric mean concentrations of both particle fractions measured across transport modes, and assessment of both the correlation between wind speed and individual trip means of UFPs and PM 2.5, and the correlation between the two particle fractions. Overall geometric mean concentrations of UFPs and PM 2.5 ranged from 2.8 (train) to 8.4 (bus) × 10 4 particles cm -3 and 22.6 (automobile) to 29.6 (bus) μg m -3, respectively, and a statistically significant difference ( p < 0.001) between modes was found for both particle fractions. Individual trip geometric mean concentrations were between 9.7 × 10 3 (train) and 2.2 × 10 5 (bus) particles cm -3 and 9.5 (train) to 78.7 (train) μg m -3. Estimated commuter exposures were variable, and the highest return trip mean PM 2.5 exposure occurred in the ferry mode, whilst the highest UFP exposure occurred during bus trips. The correlation between fractions was generally poor, and in keeping with the duality of particle mass and number emissions in vehicle-dominated urban areas. Wind speed was negatively correlated with, and a generally poor determinant of, UFP and PM 2.5 concentrations, suggesting a more significant role for other factors in determining commuter exposure.

Level of service for pedestrian movement towards the performance of passenger information in public transport stations in Klang Valley

NASA Astrophysics Data System (ADS)

Ramli, M. Z.; Hanipah, M. H.; Lee, L. G.; Loo, K. F.; Wong, J. K.; Zawawi, M. H.; Fuad, N. F. S.

2017-09-01

Rapid growth in car ownership in Malaysia plays a major role to traffic congestion. Hence, public transportation is crucial to cater the residents in high-density area especially in Klang Valley. Signage information in public transport station is one of an important passenger information system. Poor placement of sign information will decrease the efficiency of passenger flow and caused congestion in the station. Passenger information system is very useful for trip planning and decision making. Therefore, it is interesting to study the performance of passenger information system in focusing the movement behavior of pedestrian at non-peak period. Thus, the study on pedestrian movement during non-peak period on weekdays and weekends in mass transit stations and bus transit stations in Klang Valley was carried out by using video observation. The observation of the pedestrian movement was made in Mass Transit Station 1 in the middle of Kuala Lumpur and Mass Transit Station 2 in southern of Kuala Lumpur. The other site was focused at Bus Transit Station 1 in Putrajaya and Bus Transit Station 2 in Kajang. Findings shown that Mass Transit Station 1 having the best facility in terms of passenger information which the level of service obtained is LOS A, while the lowest level of service which is LOS E was obtained in Bus Transit Station 2.

Integer programming model for optimizing bus timetable using genetic algorithm

NASA Astrophysics Data System (ADS)

Wihartiko, F. D.; Buono, A.; Silalahi, B. P.

2017-01-01

Bus timetable gave an information for passengers to ensure the availability of bus services. Timetable optimal condition happened when bus trips frequency could adapt and suit with passenger demand. In the peak time, the number of bus trips would be larger than the off-peak time. If the number of bus trips were more frequent than the optimal condition, it would make a high operating cost for bus operator. Conversely, if the number of trip was less than optimal condition, it would make a bad quality service for passengers. In this paper, the bus timetabling problem would be solved by integer programming model with modified genetic algorithm. Modification was placed in the chromosomes design, initial population recovery technique, chromosomes reconstruction and chromosomes extermination on specific generation. The result of this model gave the optimal solution with accuracy 99.1%.

Electrical system architecture having high voltage bus

DOEpatents

Hoff, Brian Douglas [East Peoria, IL; Akasam, Sivaprasad [Peoria, IL

2011-03-22

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Lijuan; Gonder, Jeff; Burton, Evan

This study evaluates the costs and benefits associated with the use of a plug-in hybrid electric bus and determines the cost effectiveness relative to a conventional bus and a hybrid electric bus. A sensitivity sweep analysis was performed over a number of a different battery sizes, charging powers, and charging stations. The net present value was calculated for each vehicle design and provided the basis for the design evaluation. In all cases, given present day economic assumptions, the conventional bus achieved the lowest net present value while the optimal plug-in hybrid electric bus scenario reached lower lifetime costs than themore » hybrid electric bus. The study also performed parameter sensitivity analysis under low market potential assumptions and high market potential assumptions. The net present value of plug-in hybrid electric bus is close to that of conventional bus.« less

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

NASA Astrophysics Data System (ADS)

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

2009-05-01

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

Working conditions of bus drivers in the private sector and bus crashes in Kandy district, Sri Lanka: a case-control study.

PubMed

Jayatilleke, A U; Nakahara, S; Dharmaratne, S D; Jayatilleke, A C; Poudel, K C; Jimba, M

2009-04-01

To explore the effects of working conditions of private-bus drivers on bus crashes in Kandy district, Sri Lanka. A case-control study was carried out from August to September 2006. All private-bus drivers registered in Kandy district and involved in crashes reported to the police between November 2005 and April 2006 (n = 63) were selected as cases. Two control groups were included: private-bus drivers working on the same routes as the case drivers (n = 90) and private-bus drivers selected randomly from other routes of the district (n = 111). Data were collected using an anonymous self-administered questionnaire. Associations between working conditions and crashes were analysed using logistic regression. A strong association was observed between drivers' disagreements about working hours and bus crashes (matched controls, adjusted odds ratio (AOR) 5.98, 95% CI 1.02 to 34.90; unmatched controls, AOR 18.74, 95% CI 2.00 to 175.84). A significant association was also observed between low salaries (

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

NASA Technical Reports Server (NTRS)

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

2001-01-01

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

77 FR 27277 - FTA Supplemental Fiscal Year 2012 Apportionments, Allocations, and Program Information

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-09

... allocates Section 5309 Bus and Bus Facilities funds to bus testing and the Fuel Cell program. Tables... Fuel Cell program. FTA will issue a supplemental notice at a later date if additional contract... allocated CA, GA, MA E2012-BUSP-018 Fuel Cell Bus Program..... $13,500,000 PA E2012-BUSP-019 Bus Testing 3...

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

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Maintenance of records for urban bus... SOURCES Urban Bus Rebuild Requirements § 85.1404 Maintenance of records for urban bus operators; submittal of information; right of entry. (a) The operator of any urban bus for which this subpart is...

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

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Maintenance of records for urban bus... SOURCES Urban Bus Rebuild Requirements § 85.1404 Maintenance of records for urban bus operators; submittal of information; right of entry. (a) The operator of any urban bus for which this subpart is...

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

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Maintenance of records for urban bus... SOURCES Urban Bus Rebuild Requirements § 85.1404 Maintenance of records for urban bus operators; submittal of information; right of entry. (a) The operator of any urban bus for which this subpart is...

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

Code of Federal Regulations, 2011 CFR

2011-07-01

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

Increasing the productivity of the nation's urban transportation infrastructure: Measures to increase transit use and carpooling. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kain, J.F.; Gittell, R.; Daniere, A.

1992-01-01

The report surveys the growing use of bus and carpool priority measures to increase the productivity of the nation's transportation infrastructure. While it identifies a wide variety of priority measures, the report principally focuses on the planning and operation of exclusive and shared busways and high occupancy vehicle (HOV) facilities. It presents a variety of case studies describing the implementation of busways and transitways. The document also compares the cost effectiveness of exclusive busways and bus-HOV facilities with the cost effectiveness of recently completed light and heavy rail lines. It also explores the options and problems in serving large downtownmore » areas.« less

Design and test of data acquisition systems for the Medipix2 chip based on PC standard interfaces

NASA Astrophysics Data System (ADS)

Fanti, Viviana; Marzeddu, Roberto; Piredda, Giuseppina; Randaccio, Paolo

2005-07-01

We describe two readout systems for hybrid detectors using the Medipix2 single photon counting chip, developed within the Medipix Collaboration. The Medipix2 chip (256×256 pixels, 55 μm pitch) has an active area of about 2 cm 2 and is bump-bonded to a pixel semiconductor array of silicon or other semiconductor material. The readout systems we are developing are based on two widespread standard PC interfaces: parallel port and USB (Universal Serial Bus) version 1.1. The parallel port is the simplest PC interface even if slow and the USB is a serial bus interface present nowadays on all PCs and offering good performances.

Bus Stops and Pedestrian-Motor Vehicle Collisions in Lima, Peru: A Matched Case-Control Study

PubMed Central

Quistberg, D. Alex; Koepsell, Thomas D.; Johnston, Brian D.; Boyle, Linda Ng; Miranda, J. Jaime; Ebel, Beth E.

2015-01-01

Objective To evaluate the relationship between bus stop characteristics and pedestrian-motor vehicle collisions. Design Matched case-control study where the units of study were pedestrian crossing. Setting Random sample of 11 police commissaries in Lima, Peru. Data collection occurred from February, 2011 to September, 2011. Participants 97 intersection cases representing 1,134 collisions and 40 mid-block cases representing 469 collisions that occurred between October, 2010 and January, 2011 and their matched controls. Main Exposures Presence of a bus stop and specific bus stop characteristics. Main Outcome Occurrence of a pedestrian-motor vehicle collision. Results Intersections with bus stops were three times more likely to have a pedestrian-vehicle collision (OR 3.28, 95% CI 1.53-7.03), relative to intersections without bus stops. Both formal and informal bus stops were associated with a higher odds of a collision at intersections (OR 6.23, 95% CI 1.76-22.0 and OR 2.98, 1.37-6.49). At mid-block sites, bus stops on a bus-dedicated transit lane were also associated with collision risk (OR 2.36, 95% CI 1.02-5.42). All bus stops were located prior to the intersection, contrary to practices in most high income countries. Conclusions In urban Lima, the presence of a bus stop was associated with a three-fold increase in risk of a pedestrian collision. The highly competitive environment among bus companies may provide an economic incentive for risky practices such as dropping off passengers in the middle of traffic and jockeying for position with other buses. Bus stop placement should be considered to improve pedestrian safety. PMID:24357516

German 'Smart Bus' Systems, Potential For Application In Portland, Oregon, Volume 1, Technical Report

DOT National Transportation Integrated Search

1993-01-01

THE TRI-COUNTY METROPOLITAN TRANSPORTATION DISTRICT OF OREGON (TRI-MET) PROVIDES TRANSIT, PARATRANSIT AND RIDESHARING SERVICES WITHIN MULTNOMAH, CLACKAMAS AND WASHINGTON COUNTIES IN THE PORTLAND METROPOLITAN AREA. FOR THE PAST TWO DECADES, TRI-MET HA...

Data visualization as a tool for improved decision making within transit agencies

DOT National Transportation Integrated Search

2007-02-01

TriMet, the regional transit provider in the Portland, OR, area has been a leader in bus transit performance monitoring using data collected via automatic vehicle location and automatic passenger counter technologies. This information is collected an...

Autonomous dial-a-ride transit : benefit-cost evaluation

DOT National Transportation Integrated Search

1998-08-01

Among public transit and for-hire modes, fixed-route bus and rail are most effective in maintaining high ridership in high density areas such as urban centers. The cost effectiveness of fixed-route transit, however, depends on close proximity to the ...

Assessing air quality impacts of managed lanes.

DOT National Transportation Integrated Search

2010-12-01

Impacts on transit bus performance and air quality were investigated for a case study high-occupancy / toll (HOT) lane project on a corridor of I-95 near Miami. Trends in air pollutant concentration monitoring data in the study area first were analyz...

Assessing air quality impacts of managed lanes

DOT National Transportation Integrated Search

2010-12-01

Impacts on transit bus performance and air quality were investigated for a case study high-occupancy / : toll (HOT) lane project on a corridor of I-95 near Miami. Trends in air pollutant concentration : monitoring data in the study area first were an...

Putting a "New Kick" into the Adult Education Program

ERIC Educational Resources Information Center

Hammack, Merle S.

1978-01-01

A vocational agriculture instructor describes the adult education tour program in Ferris, Texas, involving farm bus trips and plane trips to various farming areas and industries. The trips were financed by the participants and some business firms and organizations. (MF)

DART Fixed-Route Service Review Study: Executive Summary

DOT National Transportation Integrated Search

1995-02-01

This study analyzes the probable impact of new light rail transit and commuter rail service into the Dallas Central Business District on existing Dallas Area Rapid Transit (DART) bus service. It looks at possible route and schedule modifications to e...

Evaluation of the Greenwood Drive fringe parking facility.

DOT National Transportation Integrated Search

1978-01-01

The application of a procedural method for planning express bus-fringe parking transit to determine why the Greenwood Drive service in Portsmouth, Virginia, failed to attract more riders than it did is described. The analysis of the study area reveal...

Foothill Transit Battery Electric Bus Demonstration Results

DOT National Transportation Integrated Search

2016-01-01

In October 2010, Foothill Transit began a demonstration of three Proterra battery electric buses (BEBs) in its service area located in the San Gabriel and Pomona Valley region of Los Angeles County, California. The agency had a goal of evaluating the...

Evaluation of HART MetroRapid BRT.

DOT National Transportation Integrated Search

2015-08-01

This report is a limited scope evaluation of the MetroRapids first two years of operation. The : MetroRapid represents Hillsborough Area Regional Transits first foray into bus rapid transit. Built at a : total cost of $34.75 million, or $1.98 m...

SpaceWire Plug and Play

NASA Technical Reports Server (NTRS)

Rakow, Glenn; McGuirk, Patrick; Kimmery, Clifford; Jaffe, Paul

2006-01-01

The ability to rapidly deploy inexpensive satellites to meet tactical goals has become an important goal for military space systems. In fact, Operationally Responsive Space (ORS) has been in the spotlight at the highest levels. The Office of the Secretary of Defense (OSD) has identified that the critical next step is developing the bus standards and modular interfaces. Historically, satellite components have been constructed based on bus standards and standardized interfaces. However, this has not been done to a degree, which would allow the rapid deployment of a satellite. Advancements in plug-and-play (PnP) technologies for terrestrial applications can serve as a baseline model for a PnP approach for satellite applications. Since SpaceWire (SpW) has become a de facto standard for satellite high-speed (greater than 200Mbp) on-board communications, it has become important for SpW to adapt to this Plug and Play (PnP) environment. Because SpW is simply a bulk transport protocol and lacks built-in PnP features, several changes are required to facilitate PnP with SpW. The first is for Host(s) to figure out what the network looks like, i.e., how pieces of the network, routers and nodes, are connected together; network mapping, and to receive notice of changes to the network. The second is for the components connected to the network to be understood so that they can communicate. The first element, network topology mapping & change of status indication, is being defined (topic of this paper). The second element describing how components are to communicate has been defined by ARFL with the electronic data sheets known as XTEDS. The first element, network mapping, is recent activities performed by Air Force Research Lab (ARFL), Naval Research Lab (NRL), NASA and US industry (Honeywell, Clearwater, FL, and others). This work has resulted in the development of a protocol that will perform the lower level functions of network mapping and Change Of Status (COS) indication required by Plug 'n' Play over SpaceWire. This work will be presented to the SpaceWire working group for standardization under European Cooperation for Space Standardization (ECSS) and to obtain a permanent Protocol ID (see SpaceWire Protocol ID: What Does it Mean to You; IEEE Aerospace Conference 2006). The portion of the Plug 'n' Play protocol that will be described in this paper is how the Host(s) of a SpaceWire network map the network and detect additions and deletions of devices on a SpaceWire network.

Distributed State Estimation Using a Modified Partitioned Moving Horizon Strategy for Power Systems.

PubMed

Chen, Tengpeng; Foo, Yi Shyh Eddy; Ling, K V; Chen, Xuebing

2017-10-11

In this paper, a distributed state estimation method based on moving horizon estimation (MHE) is proposed for the large-scale power system state estimation. The proposed method partitions the power systems into several local areas with non-overlapping states. Unlike the centralized approach where all measurements are sent to a processing center, the proposed method distributes the state estimation task to the local processing centers where local measurements are collected. Inspired by the partitioned moving horizon estimation (PMHE) algorithm, each local area solves a smaller optimization problem to estimate its own local states by using local measurements and estimated results from its neighboring areas. In contrast with PMHE, the error from the process model is ignored in our method. The proposed modified PMHE (mPMHE) approach can also take constraints on states into account during the optimization process such that the influence of the outliers can be further mitigated. Simulation results on the IEEE 14-bus and 118-bus systems verify that our method achieves comparable state estimation accuracy but with a significant reduction in the overall computation load.

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

PubMed

Wang, Qiqi; Zhang, Wei; Yang, Rendong; Huang, Yuanxiu; Zhang, Lin; Ning, Peishan; Cheng, Xunjie; Schwebel, David C; Hu, Guoqing; Yao, Hongyan

2015-01-01

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

Deployment strategy for battery energy storage system in distribution network based on voltage violation regulation

NASA Astrophysics Data System (ADS)

Wu, H.; Zhou, L.; Xu, T.; Fang, W. L.; He, W. G.; Liu, H. M.

2017-11-01

In order to improve the situation of voltage violation caused by the grid-connection of photovoltaic (PV) system in a distribution network, a bi-level programming model is proposed for battery energy storage system (BESS) deployment. The objective function of inner level programming is to minimize voltage violation, with the power of PV and BESS as the variables. The objective function of outer level programming is to minimize the comprehensive function originated from inner layer programming and all the BESS operating parameters, with the capacity and rated power of BESS as the variables. The differential evolution (DE) algorithm is applied to solve the model. Based on distribution network operation scenarios with photovoltaic generation under multiple alternative output modes, the simulation results of IEEE 33-bus system prove that the deployment strategy of BESS proposed in this paper is well adapted to voltage violation regulation invariable distribution network operation scenarios. It contributes to regulating voltage violation in distribution network, as well as to improve the utilization of PV systems.

Future development of the PLATO Observatory for Antarctic science

NASA Astrophysics Data System (ADS)

Ashley, Michael C. B.; Bonner, Colin S.; Everett, Jon R.; Lawrence, Jon S.; Luong-Van, Daniel; McDaid, Scott; McLaren, Campbell; Storey, John W. V.

2010-07-01

PLATO is a self-contained robotic observatory built into two 10-foot shipping containers. It has been successfully deployed at Dome A on the Antarctic plateau since January 2008, and has accumulated over 730 days of uptime at the time of writing. PLATO provides 0.5{1kW of continuous electrical power for a year from diesel engines running on Jet-A1, supplemented during the summertime with solar panels. One of the 10-foot shipping containers houses the power system and fuel, the other provides a warm environment for instruments. Two Iridium satellite modems allow 45 MB/day of data to be transferred across the internet. Future enhancements to PLATO, currently in development, include a more modular design, using lithium iron-phosphate batteries, higher power output, and a light-weight low-power version for eld deployment from a Twin Otter aircraft. Technologies used in PLATO include a CAN (Controller Area Network) bus, high-reliability PC/104 com- puters, ultracapacitors for starting the engines, and fault-tolerant redundant design.

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

A new control system hardware architecture for the Hobby-Eberly Telescope prime focus instrument package

NASA Astrophysics Data System (ADS)

Ramiller, Chuck; Taylor, Trey; Rafferty, Tom H.; Cornell, Mark E.; Rafal, Marc; Savage, Richard

2010-07-01

The Hobby-Eberly Telescope (HET) will be undergoing a major upgrade as a precursor to the HET Dark Energy Experiment (HETDEX‡). As part of this upgrade, the Prime Focus Instrument Package (PFIP) will be replaced with a new design that supports the HETDEX requirements along with the existing suite of instruments and anticipated future additions. This paper describes the new PFIP control system hardware plus the physical constraints and other considerations driving its design. Because of its location at the top end of the telescope, the new PFIP is essentially a stand-alone remote automation island containing over a dozen subsystems. Within the PFIP, motion controllers and modular IO systems are interconnected using a local Controller Area Network (CAN) bus and the CANOpen messaging protocol. CCD cameras that are equipped only with USB 2.0 interfaces are connected to a local Ethernet network via small microcontroller boards running embedded Linux. Links to ground-level systems pass through a 100 m cable bundle and use Ethernet over fiber optic cable exclusively; communications are either direct or through Ethernet/CAN gateways that pass CANOpen messages transparently. All of the control system hardware components are commercially available, designed for rugged industrial applications, and rated for extended temperature operation down to -10 °C.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Youssef, Tarek A.; Elsayed, Ahmed T.; Mohammed, Osama A.

This study presents the design and implementation of a communication and control infrastructure for smart grid operation. The proposed infrastructure enhances the reliability of the measurements and control network. The advantages of utilizing the data-centric over message-centric communication approach are discussed in the context of smart grid applications. The data distribution service (DDS) is used to implement a data-centric common data bus for the smart grid. This common data bus improves the communication reliability, enabling distributed control and smart load management. These enhancements are achieved by avoiding a single point of failure while enabling peer-to-peer communication and an automatic discoverymore » feature for dynamic participating nodes. The infrastructure and ideas presented in this paper were implemented and tested on the smart grid testbed. A toolbox and application programing interface for the testbed infrastructure are developed in order to facilitate interoperability and remote access to the testbed. This interface allows control, monitoring, and performing of experiments remotely. Furthermore, it could be used to integrate multidisciplinary testbeds to study complex cyber-physical systems (CPS).« less

GO Bus impact analysis.

DOT National Transportation Integrated Search

2013-08-01

NJ TRANSIT launched two relatively new enhanced bus services: GO 25 serving the : Springfield Avenue corridor in 2008 and GO 28 serving the Bloomfield Avenue corridor in 2009. : As an enhanced but not full Bus Rapid Transit (BRT) service, GO Bus feat...

Bus Crashworthiness Issues. Highway Special Investigation Report

DOT National Transportation Integrated Search

1999-09-01

School bus and motorcoach travel are two of the safest forms of transportation in the United States. Each year, on average, nine school bus passengers and four motorcoach passengers are fatally injured in bus crashes, according to the National Highwa...

System design of the Pioneer Venus spacecraft. Volume 11: Launch vehicle utilization

NASA Technical Reports Server (NTRS)

Varga, R. J.

1973-01-01

A summary of the spacecraft descriptions; the probe bus, large probe, small probe, and orbiter is presented. The highlights on the designs of the Atlas/Centaur spacecraft as compared to the corresponding Thor/Delta spacecraft designs are contained. A comparison is made of the two Atlas/Centaur spacecraft for reference. The major differences are the replacement of the probes of the forward end of the probe bus with the mechanically despun antenna of the orbiter and the replacement of the bicone antenna on the aft end with the orbit insertion motor. The cross sections of the large and small probes are compared. The major features of each probe are described. The Thor/Delta and Atlas/Centaur designs for the probe bus and orbiter are analyzed. The usable spacecraft mass for the Atlas/Centaur is roughly twice that for the Thor/Delta if the Type I trajectory is assumed. It is somewhat less for the Type II trajectory in the designated launch years. This additional mass capability leads to cost savings in many areas which are described.

Optimal Stabilization of Social Welfare under Small Variation of Operating Condition with Bifurcation Analysis

NASA Astrophysics Data System (ADS)

Chanda, Sandip; De, Abhinandan

2016-12-01

A social welfare optimization technique has been proposed in this paper with a developed state space based model and bifurcation analysis to offer substantial stability margin even in most inadvertent states of power system networks. The restoration of the power market dynamic price equilibrium has been negotiated in this paper, by forming Jacobian of the sensitivity matrix to regulate the state variables for the standardization of the quality of solution in worst possible contingencies of the network and even with co-option of intermittent renewable energy sources. The model has been tested in IEEE 30 bus system and illustrious particle swarm optimization has assisted the fusion of the proposed model and methodology.

Building Public Confidence in Urban Schools: It Begins inside the District. A Guide for Administrators and Board Members. A Public Relations Executives Network Project of the Council of the Great City Schools, 2009-2010

ERIC Educational Resources Information Center

Council of the Great City Schools, 2010

2010-01-01

Effective organizational communication begins with employees, who should be communications ambassadors for a district. From administrators to teachers to school bus drivers to custodians, employees set the tone for a district. The informal conversations they have at church, the bowling alley, the barbershop and other venues can make or break the…

Delay compensation in integrated communication and control systems. II - Implementation and verification

NASA Technical Reports Server (NTRS)

Luck, Rogelio; Ray, Asok

1990-01-01

The implementation and verification of the delay-compensation algorithm are addressed. The delay compensator has been experimentally verified at an IEEE 802.4 network testbed for velocity control of a DC servomotor. The performance of the delay-compensation algorithm was also examined by combined discrete-event and continuous-time simulation of the flight control system of an advanced aircraft that uses the SAE (Society of Automotive Engineers) linear token passing bus for data communications.

Tactical Airborne Distributed Computing and Networks

DTIC Science & Technology

1981-10-01

L $ IMF’BS N TRNSE DEAD DT TUEDS L FLO R.T_ B US DEU| DE AD JW A VAEN F . 9 CUL F...SAT 41, rue Cantagrel PARIS 136me RESUME Ce textetexpose Iles risultats pour la partie procidure de l ’&tude d’un systime d’ichal~ges ultraflabla 5...vis du bus. LTýSS egicute un microprograime canal qui interprite les instructions de gestion des seuls mes- sages int~ressant. l 𔄀quipEiient. L

SPring-8 beamline control system.

PubMed

Ohata, T; Konishi, H; Kimura, H; Furukawa, Y; Tamasaku, K; Nakatani, T; Tanabe, T; Matsumoto, N; Ishii, M; Ishikawa, T

1998-05-01

The SPring-8 beamline control system is now taking part in the control of the insertion device (ID), front end, beam transportation channel and all interlock systems of the beamline: it will supply a highly standardized environment of apparatus control for collaborative researchers. In particular, ID operation is very important in a third-generation synchrotron light source facility. It is also very important to consider the security system because the ID is part of the storage ring and is therefore governed by the synchrotron ring control system. The progress of computer networking systems and the technology of security control require the development of a highly flexible control system. An interlock system that is independent of the control system has increased the reliability. For the beamline control system the so-called standard model concept has been adopted. VME-bus (VME) is used as the front-end control system and a UNIX workstation as the operator console. CPU boards of the VME-bus are RISC processor-based board computers operated by a LynxOS-based HP-RT real-time operating system. The workstation and the VME are linked to each other by a network, and form the distributed system. The HP 9000/700 series with HP-UX and the HP 9000/743rt series with HP-RT are used. All the controllable apparatus may be operated from any workstation.

Further validation of artificial neural network-based emissions simulation models for conventional and hybrid electric vehicles.

PubMed

Tóth-Nagy, Csaba; Conley, John J; Jarrett, Ronald P; Clark, Nigel N

2006-07-01

With the advent of hybrid electric vehicles, computer-based vehicle simulation becomes more useful to the engineer and designer trying to optimize the complex combination of control strategy, power plant, drive train, vehicle, and driving conditions. With the desire to incorporate emissions as a design criterion, researchers at West Virginia University have developed artificial neural network (ANN) models for predicting emissions from heavy-duty vehicles. The ANN models were trained on engine and exhaust emissions data collected from transient dynamometer tests of heavy-duty diesel engines then used to predict emissions based on engine speed and torque data from simulated operation of a tractor truck and hybrid electric bus. Simulated vehicle operation was performed with the ADVISOR software package. Predicted emissions (carbon dioxide [CO2] and oxides of nitrogen [NO(x)]) were then compared with actual emissions data collected from chassis dynamometer tests of similar vehicles. This paper expands on previous research to include different driving cycles for the hybrid electric bus and varying weights of the conventional truck. Results showed that different hybrid control strategies had a significant effect on engine behavior (and, thus, emissions) and may affect emissions during different driving cycles. The ANN models underpredicted emissions of CO2 and NO(x) in the case of a class-8 truck but were more accurate as the truck weight increased.

Transit Bus Fuel Economy and Performance Simulation

DOT National Transportation Integrated Search

1984-01-01

This report presents the results of bus simulation studies to determine the effects of various design and operating parameters on bus fuel economy and performance. The bus components are first described in terms of how they are modeled. Then a variat...

75 FR 52054 - Bus and Bus Facilities Discretionary Program Funds

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-24

... engaged in public transportation, or private non-profit organizations. FOR FURTHER INFORMATION CONTACT... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Bus and Bus Facilities Discretionary... program announcement of project selections. SUMMARY: The U.S. Department of Transportation's (DOT) Federal...

Effectiveness of Bus Signal Priority : Final Report

DOT National Transportation Integrated Search

2002-01-01

Effectiveness of Bus Signal Priority (BSP) study evaluates BSP?s impact on traffic operations. The goal was to examine how different situations, such as the level of congestion, placement of bus stops, presence of express bus service, and number of t...

American Fuel Cell Bus Project : First Analysis Report

DOT National Transportation Integrated Search

2013-06-01

This report summarizes the experience and early results from the American Fuel Cell Bus Project, a fuel cell electric bus demonstration funded by the Federal Transit Administration (FTA) under the National Fuel Cell Bus Program. A team led by CALSTAR...

American fuel cell bus project : first analysis report.

DOT National Transportation Integrated Search

2013-06-01

This report summarizes the experience and early results from the American Fuel Cell Bus Project, a fuel cell electric bus demonstration : funded by the Federal Transit Administration (FTA) under the National Fuel Cell Bus Program. A team led by CALST...

Optical technology for flight control systems

NASA Technical Reports Server (NTRS)

Mayanagi, M.

1986-01-01

Optical applications to the flight control system including optical data bus, sensors, and transducers are analyzed. Examples of optical data bus include airborne light optical fiber technology (ALOFT), F-5E, YA-7D, MIL-STD-1553 fiber optic data bus and NAL-optic data bus. This NAL-optic data bus is applied to STOL, and its characteristics are stressed. Principles and advantages of optical pulse-digital transducers are discussed.

Analyzing the Relationship Between Bus Pollution Policies and Morbidity Using a Quasi-Experiment

PubMed Central

Ngo, Nicole S.

2015-01-01

Abstract Transit buses are used by millions of commuters every day, but they emit toxic diesel fumes. In 1988, the U.S. Environmental Protection Agency implemented emission standards for transit buses, which have been continually updated. Yet there is no quantitative evidence of the health benefits from these bus pollution policies due to data constraints and confounding variables. In this study, a quasi-experiment is used to exploit the geographic and temporal variation in emission standards by using bus vintage as a proxy for bus emissions. This is accomplished using a unique, rich panel data set, which includes daily information on bus vintage and route for the New York City Transit bus fleet between 2006 and 2009. This information is merged with daily data on emergency department (ED) visits for respiratory illnesses, which include patients’ residences at the census block level and exact admission date. Economic benefits resulting from these bus pollution policies are then estimated. Results show that stricter transit bus emission standards by the U.S. Environmental Protection Agency for particulate matter are associated with reduced ED visits for respiratory diseases for patients living within a few hundred feet of a bus route. These findings demonstrate that bus pollution policies have made critical improvements to public health. PMID:26376392

Analyzing the Relationship Between Bus Pollution Policies and Morbidity Using a Quasi-Experiment.

PubMed

Ngo, Nicole S

2015-09-01

Transit buses are used by millions of commuters every day, but they emit toxic diesel fumes. In 1988, the U.S. Environmental Protection Agency implemented emission standards for transit buses, which have been continually updated. Yet there is no quantitative evidence of the health benefits from these bus pollution policies due to data constraints and confounding variables. In this study, a quasi-experiment is used to exploit the geographic and temporal variation in emission standards by using bus vintage as a proxy for bus emissions. This is accomplished using a unique, rich panel data set, which includes daily information on bus vintage and route for the New York City Transit bus fleet between 2006 and 2009. This information is merged with daily data on emergency department (ED) visits for respiratory illnesses, which include patients' residences at the census block level and exact admission date. Economic benefits resulting from these bus pollution policies are then estimated. Results show that stricter transit bus emission standards by the U.S. Environmental Protection Agency for particulate matter are associated with reduced ED visits for respiratory diseases for patients living within a few hundred feet of a bus route. These findings demonstrate that bus pollution policies have made critical improvements to public health.

49 CFR 605.11 - Exemptions.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) That private school bus operators in the urban area are unable to provide adequate transportation, at a... 49 Transportation 7 2010-10-01 2010-10-01 false Exemptions. 605.11 Section 605.11 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF...

2006 evaluation of the Las Vegas Metropolitan Area Express (MAX) bus rapid transit project : December 1, 2006

DOT National Transportation Integrated Search

2006-12-01

The surface transportation system plays a crucial role in responding to natural disasters, terrorist acts, and other catastrophic events. The Disaster Response and Evacuation (DRE) User Service uses intelligent transportation systems (ITS) to enhance...

The Status of Spacecraft Bus and Platform Technology Development Under the NASA ISPT Program

NASA Technical Reports Server (NTRS)

Anderson, David; Munk, Michelle M.; Pencil, Eric; Dankanich, John; Glaab, Louis; Peterson, Todd

2014-01-01

The In-Space Propulsion Technology (ISPT) program is developing spacecraft bus and platform technologies that will enable or enhance NASA robotic science missions. The ISPT program is currently developing technology in three areas that include Propulsion System Technologies, Entry Vehicle Technologies, and Systems Mission Analysis. ISPTs propulsion technologies include: 1) NASAs Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system; 2) a Hall-effect electric propulsion (HEP) system for sample return and low cost missions; 3) the Advanced Xenon Flow Control System (AXFS); ultra-lightweight propellant tank technologies (ULTT); and propulsion technologies for a Mars Ascent Vehicle (MAV). The AXFS and ULTT are two component technologies being developed with nearer-term flight infusion in mind, whereas NEXT and the HEP are being developed as EP systems. ISPTs entry vehicle technologies are: 1) Aerocapture technology development with investments in a family of thermal protection system (TPS) materials and structures; guidance, navigation, and control (GNC) models of blunt-body rigid aeroshells; and aerothermal effect models; and 2) Multi-mission technologies for Earth Entry Vehicles (MMEEV) for sample return missions. The Systems Mission Analysis area is focused on developing tools and assessing the application of propulsion, entry vehicle, and spacecraft bus technologies to a wide variety of mission concepts. Several of the ISPT technologies are related to sample return missions and other spacecraft bus technology needs like: MAV propulsion, MMEEV, and electric propulsion. These technologies, as well as Aerocapture, are more vehicle and mission-focused, and present a different set of technology development challenges. These in-space propulsion technologies are applicable, and potentially enabling for future NASA Discovery, New Frontiers, Flagship and sample return missions currently under consideration. This paper provides a brief overview of the ISPT program, describing the development status and technology infusion readiness.

Traffic rule violations of private bus drivers and bus crashes in Sri Lanka: a case-control study.

PubMed

Jayatilleke, Achala Upendra; Poudel, Krishna C; Nakahara, Shinji; Dharmaratne, Samath D; Jayatilleke, Achini Chinthika; Jimba, Masamine

2010-06-01

To explore the association between self-reported traffic rule violations of private sector bus drivers and bus crashes in the Kandy district, Sri Lanka. We carried out a case-control study from August to September 2006. Cases were all the private bus drivers registered in the Kandy district and involved in crashes reported to the police between November 2005 and April 2006 (n = 63). We included two control groups: the private bus drivers working on the same routes of the cases (n = 90; matched controls) and the drivers selected randomly from the other routes of the district (n = 111; unmatched controls). We used a self-administered questionnaire to collect data on the self-reported traffic rule violations and analyzed the association between the self-reported traffic rule violations and crashes using logistic regression. The following variables showed significant associations with private bus crashes: illegal overtaking (matched controls, adjusted odds ratio [AOR] = 14.78, unmatched controls, AOR = 1.04), taking passengers outside the bus bays (matched controls, AOR = 3.96, unmatched controls, AOR = 2.29), and overloading (matched controls, AOR = 10.26, unmatched controls, AOR = 1.93). However, we did not observe an association between high-speed driving and bus crashes matched controls, AOR = 1.22, unmatched controls, AOR = 0.81. Traffic rule violations, such as illegal overtaking, overloading, and taking passengers outside the bus bays, are significant risk factors for private bus crashes in Sri Lanka.

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

PubMed Central

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

2015-01-01

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

Trends in bus transit operations, 1960-1974

DOT National Transportation Integrated Search

1977-01-01

This report analyzes the historical patterns of bus transit operations from 1960 to 1974 using data from 50 bus operations. Because of limitations on the available data, the analyzed data do not represent the universe of bus operations, nor is it a r...

Modular Cooling Components

NASA Technical Reports Server (NTRS)

Eastman, G. Yale; Dussinger, Peter M.; Hartenstine, John R.

1994-01-01

Three modular heat-transfer components designed for use together or separately. Simple mechanical connections facilitate assembly of these and related heat-transfer components into cooling systems of various configurations, such as to cool laboratory equipment rearranged for different experiments. Components are clamp-on cold plate, cold plate attached to flexible heat pipe, and thermal-bus receptacle. Clamp-on cold plate moved to any convenient location for attachment of equipment cooled by it, then clamped onto thermal bus. Heat from equipment conducted through plate and into coolant. Thermal-bus receptacle integral with thermal bus. Includes part of thermal bus to which clamp-on cold plate attached, plus tapered socket into which condenser end of flexible heat pipe plugged. Thermal-bus receptacle includes heat-pipe wick structure using coolant in bus to enhance transfer of heat from cold plate.

Relative importance of school bus-related microenvironments to children's pollutant exposure.

PubMed

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

2005-10-01

Real-time concentrations of black carbon, particle-bound polycyclic aromatic hydrocarbons, nitrogen dioxide, and fine particulate counts, as well as integrated and real-time fine particulate matter (PM2.5) mass concentrations were measured inside school buses during long commutes on Los Angeles Unified School District bus routes, at bus stops along the routes, at the bus loading/unloading zone in front of the selected school, and at nearby urban "background" sites. Across all of the pollutants, mean concentrations during bus commutes were higher than in any other microenvironment. Mean exposures (mean concentration times time spent in a particular microenvironment) in bus commutes were between 50 and 200 times greater than those for the loading/unloading microenvironment, and 20-40 times higher than those for the bus stops, depending on the pollutant. Although the analyzed school bus commutes represented only 10% of a child's day, on average they contributed one-third of a child's 24-hr overall black carbon exposure during a school day. For species closely related to vehicle exhaust, the within- cabin exposures were generally dominated by the effect of surrounding traffic when windows were open and by the bus's own exhaust when windows were closed. Low-emitting buses generally exhibited high concentrations only when traveling behind a diesel vehicle, whereas high-emitting buses exhibited high concentrations both when following other diesel vehicles and when idling without another diesel vehicle in front of the bus. To reduce school bus commute exposures, we recommend minimizing commute times, avoiding caravanning with other school buses, using the cleanest buses for the longest bus routes, maintaining conventional diesel buses to eliminate visible emissions, and transitioning to cleaner fuels and advanced particulate control technologies as soon as possible.

Analysis of a diesel-electric hybrid urban bus system

NASA Astrophysics Data System (ADS)

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

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

Measuring self-pollution in school buses using a tracer gas technique

NASA Astrophysics Data System (ADS)

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

A potentially important, but inadequately studied, source of children's exposure to pollutants during school bus commutes is the introduction of a bus's own exhaust into the passenger compartment. We developed and applied a method to determine the amount of a bus's own exhaust penetrating into the cabin in a study of six in-use school buses over a range of routes, roadway types, fuels, and emission control technologies. A tracer gas, SF 6, was metered into the bus's exhaust system using a mass flow controller whose flow rate was logged by a data acquisition system and processed with the concurrent real-time pollutant measurement data. At the same time, the SF 6 concentration inside the bus was measured using an AeroVironment CTA-1000 continuous analyzer connected to a series of solenoids that switched the sample inlet between the front and rear of the bus cabin. To account for a baseline drift of the CTA-1000, SF 6-free air was also drawn through a line located outside at the front of the bus. Although this third sample line generally provided a reference zero value, it also showed that under certain wind conditions (i.e., wind from the rear) when the bus was stopped and was idling, significant amounts of the bus's own exhaust reached this location at the front of the bus. Self-pollution, the percentage of a bus's own exhaust that can be found inside its cabin, was a function of bus type and age, and a strong function of window position (i.e., open or closed). We estimated up to 0.3% of the air inside the cabin was from the bus's own exhaust in older buses, approximately 10 times the percentage observed for newer buses, and 25% of the black carbon concentration variance was explained by the buses' self-pollution. Analysis of the tracer gas concentrations provided a powerful tool for identifying potentially high-exposure conditions.

Transit bus life cycle cost and year 2007 emissions estimation.

DOT National Transportation Integrated Search

2007-06-01

The report presents a study of transit bus life cycle cost (LCC) analysis, and projected transit bus emissions and fuel economy for 2007 : model year buses. It covers four bus types: diesel buses using ultra low sulfur diesel (ULSD), diesel buses usi...

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

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-16

... DEPARTMENT OF TRANSPORTATION Federal Transit Administration Over-the-Road Bus Accessibility... ``Over-the-Road Bus Accessibility Program Grants,'' extends the application deadline, and allows... comply with the terms and conditions of the Special Warranty for the Over-the-Road Bus Accessibility...

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

NASA Technical Reports Server (NTRS)

Gerber, C. R.

1972-01-01

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

Large school bus design vehicle dimensions

DOT National Transportation Integrated Search

1998-09-01

A survey of United States school bus operators and manufacturers was conducted to define the larger sizes of school buses in regular use. A mid-60 passenger type-c bus (SB-C) and a mid-80 passenger type-D bus (SB-D) were selected as design vehicles. ...

National fuel cell bus program : proterra fuel cell hybrid bus report, Columbia demonstration.

DOT National Transportation Integrated Search

2011-10-01

This report summarizes the experience and early results from a fuel cell bus demonstration funded by the Federal Transit Administration (FTA) under the National Fuel Cell Bus Program. A team led by the Center for Transportation and the Environment an...

Comparing emission rates derived from a model with a plume-based approach and quantifying the contribution of vehicle classes to on-road emissions and air quality.

PubMed

Xu, Junshi; Wang, Jonathan; Hilker, Nathan; Fallah-Shorshani, Masoud; Saleh, Marc; Tu, Ran; Wang, An; Minet, Laura; Stogios, Christos; Evans, Greg; Hatzopoulou, Marianne

2018-06-05

This study presents a comparison of fleet averaged emission factors (EFs) derived from a traffic emission model with EFs estimated using plume-based measurements, including an investigation of the contribution of vehicle classes to carbon monoxide (CO), nitrogen oxides (NO x ), and elemental carbon (EC) along an urban corridor. To this end, a field campaign was conducted over one week in June 2016 on an arterial road in Toronto, Canada. Traffic data were collected using a traffic camera and a radar, while air quality was characterized using two monitoring stations: one located at ground-level and another at the rooftop of a four-storey building. A traffic simulation model was calibrated and validated and sec-by-sec speed profiles for all vehicle trajectories were extracted to model emissions. In addition, dispersion modelling was conducted to identify the extent to which differences in emissions translate to differences in near-road concentrations. Our results indicate that modelled EFs for CO and NO x are twice as high as plume-based EFs. Besides, modelled results indicate that transit bus emissions accounted for 60% and 70% of the total emissions of NO x and EC. Transit bus emission rates in g/passenger.km for NO x and EC were up to 8 and 22 times the emission rates of passenger cars. In contrast, the Toronto streetcars, which are electrically fuelled, were found to improve near-road air quality despite their negative impact on traffic speeds. Finally, we observe that the difference in estimated concentrations derived from the two methods is not as large as the difference in estimated emissions due to the influence of meteorology and of the urban background given that the study network is located in a busy downtown area. Implications This study presents a comparison of fleet averaged emission factors (EFs) derived from a traffic emission model with EFs estimated using plume-based measurements, including an investigation of the contribution of vehicle classes to various pollutants. Besides, dispersion modelling was conducted to identify the extent to which differences in emissions translate to differences in near-road concentrations. We observe that the difference in estimated concentrations derived from the two methods is not as large as the difference in estimated emissions due to the influence of meteorology and of the urban background as the study network is located in a busy downtown area.

Improving acute care through use of medical device data.

PubMed

Kennelly, R J

1998-02-01

The Medical Information Bus (MIB) is a data communications standard for bedside patient connected medical devices. It is formally titled IEEE 1073 Standard for Medical Device Communications. MIB defines a complete seven layer communications stack for devices in acute care settings. All of the design trade-offs in writing the standard were taken to optimize performance in acute care settings. The key clinician based constraints on network performance are: (1) the network must be able to withstand multiple daily reconfigurations due to patient movement and condition changes; (2) the network must be 'plug-and-play' to allow clinicians to set up the network by simply plugging in a connector, taking no other actions; (3) the network must allow for unambiguous associations of devices with specific patients. A network of this type will be used by clinicians, thus giving complete, accurate, real time data from patient connected devices. This capability leads to many possible improvements in patient care and hospital cost reduction. The possible uses for comprehensive automatic data capture are only limited by imagination and creativity of clinicians adapting to the new hospital business paradigm.

Multiple output power supply circuit for an ion engine with shared upper inverter

NASA Technical Reports Server (NTRS)

Cardwell, Jr., Gilbert I. (Inventor); Phelps, Thomas K. (Inventor)

2001-01-01

A power supply circuit for an ion engine suitable for a spacecraft is coupled to a bus having a bus input and a bus return. The power supply circuit has a first primary winding of a first transformer. An upper inverter circuit is coupled to the bus input and the first primary winding. The power supply circuit further includes a first lower inverter circuit coupled to the bus return and the first primary winding. The second primary winding of a second transformer is coupled to the upper inverter circuit. A second lower inverter circuit is coupled to the bus return and the second primary winding.

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

PubMed

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

2008-06-01

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

Survey on the implementation and reliability of CubeSat electrical bus interfaces

NASA Astrophysics Data System (ADS)

Bouwmeester, Jasper; Langer, Martin; Gill, Eberhard

2017-06-01

This paper provides results and conclusions on a survey on the implementation and reliability aspects of CubeSat bus interfaces, with an emphasis on the data bus and power distribution. It provides recommendations for a future CubeSat bus standard. The survey is based on a literature study and a questionnaire representing 60 launched CubeSats and 44 to be launched CubeSats. It is found that the bus interfaces are not the main driver for mission failures. However, it is concluded that the Inter Integrated Circuit (I2C) data bus, as implemented in a great majority of the CubeSats, caused some catastrophic satellite failures and a vast amount of bus lockups. The power distribution may lead to catastrophic failures if the power lines are not protected against overcurrent. A connector and wiring standard widely implemented in CubeSats is based on the PC/104 standard. Most participants find the 104 pin connector of this standard too large. For a future CubeSat bus interface standard, it is recommended to implement a reliable data bus, a power distribution with overcurrent protection and a wiring harness with smaller connectors compared with PC/104.

[Investigation on events of bus on fire in 6 years in the mainland of China].

PubMed

Wang, X G; Liu, Y; Cen, Y; Wu, P; Zhou, H L; Han, C M

2016-12-20

Objective: To retrospectively analyze the characteristics of events of bus on fire in 6 years in the mainland of China. Methods: Events of bus on fire happened between January 2009 and December 2014 were retrieved through Baidu search engine, Chinese Journals Full - text Database, and PubMed database in the search strategy with " bus" and " fire" or " arson" as keywords combined with the name of provinces, autonomous regions, and municipalities of the mainland of China. The occurrence time, region, cause of fire, casualties of each event were recorded, and the correlative analysis was conducted. Data were processed with Microsoft Excel software. Results: Totally 287 events of bus on fire were retrieved, among which 49 events happened in 2009, 36 events happened in 2010, 35 events happened in 2011, 37 events happened in 2012, and respectively 65 events happened in 2013 and 2014. The events of bus on fire most frequently happened in June and July, respectively 49 and 39 events. Among the distribution of occurrence regions of events of bus on fire, there were 78 events (27.18%) in east China, 52 events (18.12%) in northeast China, 41 events (14.29%) both in north China and south China. Among the causes of events of bus on fire, spontaneous combustion of bus ranked in the first (267 events, accounting for 93.03%), followed by arson (13 events, accounting for 4.53%). Among the 13 events of bus on fire caused by arson, 7 events happened between 16: 00 and 20: 00, and 3 events happened between 8: 00 and 10: 00. Totally 27 events of bus on fire (9.41%) were with casualties, among which 13 events (48.15%) were caused by spontaneous combustion of bus, 10 events (37.04%) were caused by arson, and 4 events (14.81%) were caused by traffic accidents. Arson caused the most severe casualties (at least 88 deaths and 287 injuries), followed by spontaneous combustion of bus (at least 35 deaths and 140 injuries) and traffic accidents (at least 9 deaths and 20 injuries). Conclusions: Events of bus on fire happened more frequently in recent years in the mainland of China, and the frequencies were much higher especially in June and July. Most events were caused by spontaneous combustion of bus, followed by arson. Most of the events of bus on fire caused by arson happened in the morning and evening rush hours of urban traffic, and althouth the occurrence rate was not high, the casualties were most severe.

School Planning Safe Transporting.

ERIC Educational Resources Information Center

New Jersey State Dept. of Education, Trenton. Bureau of Pupil Transportation.

Prepared for boards of education and municipal planning authorities, school site selection is related to school bus safety. Consideration of direction and density of traffic flow, street crossings, curbing, drainage, road width, parking areas, number of pupils and personnel, number of buses, method of transportation, schedules and extra-curricular…

Department of Homeland Security Assistance to States and Localities: A Summary and Issues for the 111th Congress

DTIC Science & Technology

2009-02-26

6 Intercity Passenger Rail Program (Amtrak...6 Intercity Bus Security Grant Program................................................................................. 7...for its intercity rail services between high-risk urban areas. 20 U.S. Department of Homeland Security, Federal Emergency Management Agency

Spatial spreading of infectious disease via local and national mobility networks in South Korea

NASA Astrophysics Data System (ADS)

Kwon, Okyu; Son, Woo-Sik

2017-12-01

We study the spread of infectious disease based on local- and national-scale mobility networks. We construct a local mobility network using data on urban bus services to estimate local-scale movement of people. We also construct a national mobility network from orientation-destination data of vehicular traffic between highway tollgates to evaluate national-scale movement of people. A metapopulation model is used to simulate the spread of epidemics. Thus, the number of infected people is simulated using a susceptible-infectious-recovered (SIR) model within the administrative division, and inter-division spread of infected people is determined through local and national mobility networks. In this paper, we consider two scenarios for epidemic spread. In the first, the infectious disease only spreads through local-scale movement of people, that is, the local mobility network. In the second, it spreads via both local and national mobility networks. For the former, the simulation results show infected people sequentially spread to neighboring divisions. Yet for the latter, we observe a faster spreading pattern to distant divisions. Thus, we confirm the national mobility network enhances synchronization among the incidence profiles of all administrative divisions.

Physical and Chemical Characterization of Real-World Particle Number and Mass Emissions from City Buses in Finland.

PubMed

Pirjola, Liisa; Dittrich, Aleš; Niemi, Jarkko V; Saarikoski, Sanna; Timonen, Hilkka; Kuuluvainen, Heino; Järvinen, Anssi; Kousa, Anu; Rönkkö, Topi; Hillamo, Risto

2016-01-05

Exhaust emissions of 23 individual city buses at Euro III, Euro IV and EEV (Enhanced Environmentally Friendly Vehicle) emission levels were measured by the chasing method under real-world conditions at a depot area and on the normal route of bus line 24 in Helsinki. The buses represented different technologies from the viewpoint of engines, exhaust after-treatment systems (ATS) and fuels. Some of the EEV buses were fueled by diesel, diesel-electric, ethanol (RED95) and compressed natural gas (CNG). At the depot area the emission factors were in the range of 0.3-21 × 10(14) # (kg fuel)(-1), 6-40 g (kg fuel)(-1), 0.004-0.88 g (kg fuel)(-1), 0.004-0.56 g (kg fuel)(-1), 0.01-1.2 g (kg fuel)(-1), for particle number (EFN), nitrogen oxides (EFNOx), black carbon (EFBC), organics (EFOrg), and particle mass (EFPM1), respectively. The highest particulate emissions were observed from the Euro III and Euro IV buses and the lowest from the ethanol and CNG-fueled buses, which emitted BC only during acceleration. The organics emitted from the CNG-fueled buses were clearly less oxidized compared to the other bus types. The bus line experiments showed that lowest emissions were obtained from the ethanol-fueled buses whereas large variation existed between individual buses of the same type indicating that the operating conditions by drivers had large effect on the emissions.

Knowledge, Risk Perception and Practice Regarding Tuberculosis Transmission among Long Distance Bus Drivers in Addis Ababa, Ethiopia: A Cross Sectional Study.

PubMed

Gebrehiwot, Tsegaye Tewelde; Tesfamichael, Fessahaye Alemseged

2017-11-01

Window opening during bus transportation is recommended as a tuberculosis prevention strategy.Yet, drivers are affected by lack knowledge and risk perception of passengers and assistants. Boosting knowledge of and notifying the high risk of tuberculosis transmission for every passenger could be too costly. However, strategies targeting bus drivers as key agents unlike targeting all passengers might be less costly for window opening. Data were collected from November 18/2014 to December 21/2014 in inter-region bus stations of Addis Ababa using cross sectional study design. Samples of 306 participants were selected using simple random sampling, and data were collected through face-to-face interview. Data were entered into Epi-data version 3.1 andanalyzed using IBM SPSS version 21. From a sample of 306 bus drivers, 303 were interviewed. Nine in ten and nearly half of participants believed in the need for opening all windows and avoiding overcrowding of passengers as TB preventive measures respectively. Few bus drivers (7.3%) believed that bus drivers and their assistants could be at risk of tuberculosis. The majority (85.7%) of bus drivers opened side window the whole day without precondition. Hearing tuberculosis related information from radio was a promoting factor for tuberculosis preventive measures among bus drivers. Tuberculosis preventive practices and knowledge of bus drivers seempositive (opportunities), despite their low risk perception (challenge). Using the opportunity, further empowering bus drivers to persuade passengers and assistants to open all the rest of the windows is needed.

Analysis, operation and maintenance of a fuel cell/battery series-hybrid bus for urban transit applications

NASA Astrophysics Data System (ADS)

Bubna, Piyush; Brunner, Doug; Gangloff, John J.; Advani, Suresh G.; Prasad, Ajay K.

The fuel cell hybrid bus (FCHB) program was initiated at the University of Delaware in 2005 to demonstrate the viability of fuel cell vehicles for transit applications and to conduct research and development to facilitate the path towards their eventual commercialization. Unlike other fuel cell bus programs, the University of Delaware's FCHB design features a battery-heavy hybrid which offers multiple advantages in terms of cost, performance and durability. The current fuel cell hybrid bus is driven on a regular transit route at the University of Delaware. The paper describes the baseline specifications of the bus with a focus on the fuel cell and the balance of plant. The fuel cell/battery series-hybrid design is well suited for urban transit routes and provides key operational advantages such as hydrogen fuel economy, efficient use of the fuel cell for battery recharging, and regenerative braking. The bus is equipped with a variety of sensors including a custom-designed cell voltage monitoring system which provide a good understanding of bus performance under normal operation. Real-time data collection and analysis have yielded key insights for fuel cell bus design optimization. Results presented here illustrate the complex flow of energy within the various subsystems of the fuel cell hybrid bus. A description of maintenance events has been included to highlight the issues that arise during general operation. The paper also describes several modifications that will facilitate design improvements in future versions of the bus. Overall, the fuel cell hybrid bus demonstrates the viability of fuel cells for urban transit applications in real world conditions.

Dynamic Control of Facts Devices to Enable Large Scale Penetration of Renewable Energy Resources

NASA Astrophysics Data System (ADS)

Chavan, Govind Sahadeo

This thesis focuses on some of the problems caused by large scale penetration of Renewable Energy Resources within EHV transmission networks, and investigates some approaches in resolving these problems. In chapter 4, a reduced-order model of the 500 kV WECC transmission system is developed by estimating its key parameters from phasor measurement unit (PMU) data. The model was then implemented in RTDS and was investigated for its accuracy with respect to the PMU data. Finally it was tested for observing the effects of various contingencies like transmission line loss, generation loss and large scale penetration of wind farms on EHV transmission systems. Chapter 5 introduces Static Series Synchronous Compensators (SSSC) which are seriesconnected converters that can control real power flow along a transmission line. A new application of SSSCs in mitigating Ferranti effect on unloaded transmission lines was demonstrated on PSCAD. A new control scheme for SSSCs based on the Cascaded H-bridge (CHB) converter configuration was proposed and was demonstrated using PSCAD and RTDS. A new centralized controller was developed for the distributed SSSCs based on some of the concepts used in the CHB-based SSSC. The controller's efficacy was demonstrated using RTDS. Finally chapter 6 introduces the problem of power oscillations induced by renewable sources in a transmission network. A power oscillation damping (POD) controller is designed using distributed SSSCs in NYPA's 345 kV three-bus AC system and its efficacy is demonstrated in PSCAD. A similar POD controller is then designed for the CHB-based SSSC in the IEEE 14 bus system in PSCAD. Both controllers were noted to have significantly damped power oscillations in the transmission networks.

Security awareness for public bus transportation : case studies of attacks against the Israeli public bus system [research brief].

DOT National Transportation Integrated Search

2012-03-01

Government regulators and transportation operators of public bus systems are concerned about terrorist attacks. Bus attacks in Israel between late September 2000 and the end of 2006, a period known as the Second Intifada, are particularly well known....

Security awareness for public bus transportation : case studies of attacks against the Israeli public bus system.

DOT National Transportation Integrated Search

2012-03-01

This report presents 16 case studies of attacks planned or carried out against Israeli bus targets, along with statistical data on the number, frequency, and lethality of attacks against bus targets that have taken place in Israel since 1970 and duri...

Research Electrical Distribution Bus | Energy Systems Integration Facility

Science.gov Websites

| NREL Research Electrical Distribution Bus Research Electrical Distribution Bus The research electrical distribution bus (REDB) is the heart of the Energy Systems Integration Facility electrical system throughout the laboratories. Photo of a technician performing maintenance on the Research Electrical

Alternative Fuels Data Center

Science.gov Websites

School Bus Clean School Bus is a public-private partnership that focuses on reducing children's exposure to harmful diesel exhaust by limiting school bus idling, implementing pollution reduction technologies, improving route logistics, and switching to clean fuels. Clean School Bus is part of the U.S

Recommendations for yield-to-bus traffic control devices and bus pullout bays design characteristics : [research summary].

DOT National Transportation Integrated Search

2013-04-01

Bus pullout bays are being installed increasingly : on Floridas roads as a safety factor and so that : stopped buses do not impede traffic. In Florida, : state law requires car drivers to yield to buses : when a bus needs to reenter the roadway af...

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

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 220; School bus rollover protection... STANDARDS Federal Motor Vehicle Safety Standards § 571.220 Standard No. 220; School bus rollover protection. S1. Scope. This standard establishes performance requirements for school bus rollover protection. S2...

Robust planning of dynamic wireless charging infrastructure for battery electric buses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Zhaocai; Song, Ziqi

Battery electric buses with zero tailpipe emissions have great potential in improving environmental sustainability and livability of urban areas. However, the problems of high cost and limited range associated with on-board batteries have substantially limited the popularity of battery electric buses. The technology of dynamic wireless power transfer (DWPT), which provides bus operators with the ability to charge buses while in motion, may be able to effectively alleviate the drawbacks of electric buses. In this paper, we address the problem of simultaneously selecting the optimal location of the DWPT facilities and designing the optimal battery sizes of electric buses formore » a DWPT electric bus system. The problem is first constructed as a deterministic model in which the uncertainty of energy consumption and travel time of electric buses is neglected. The methodology of robust optimization (RO) is then adopted to address the uncertainty of energy consumption and travel time. The affinely adjustable robust counterpart (AARC) of the deterministic model is developed, and its equivalent tractable mathematical programming is derived. Both the deterministic model and the robust model are demonstrated with a real-world bus system. The results of our study demonstrate that the proposed deterministic model can effectively determine the allocation of DWPT facilities and the battery sizes of electric buses for a DWPT electric bus system; and the robust model can further provide optimal designs that are robust against the uncertainty of energy consumption and travel time for electric buses.« less

Robust planning of dynamic wireless charging infrastructure for battery electric buses

DOE PAGES

Liu, Zhaocai; Song, Ziqi

2017-10-01

Battery electric buses with zero tailpipe emissions have great potential in improving environmental sustainability and livability of urban areas. However, the problems of high cost and limited range associated with on-board batteries have substantially limited the popularity of battery electric buses. The technology of dynamic wireless power transfer (DWPT), which provides bus operators with the ability to charge buses while in motion, may be able to effectively alleviate the drawbacks of electric buses. In this paper, we address the problem of simultaneously selecting the optimal location of the DWPT facilities and designing the optimal battery sizes of electric buses formore » a DWPT electric bus system. The problem is first constructed as a deterministic model in which the uncertainty of energy consumption and travel time of electric buses is neglected. The methodology of robust optimization (RO) is then adopted to address the uncertainty of energy consumption and travel time. The affinely adjustable robust counterpart (AARC) of the deterministic model is developed, and its equivalent tractable mathematical programming is derived. Both the deterministic model and the robust model are demonstrated with a real-world bus system. The results of our study demonstrate that the proposed deterministic model can effectively determine the allocation of DWPT facilities and the battery sizes of electric buses for a DWPT electric bus system; and the robust model can further provide optimal designs that are robust against the uncertainty of energy consumption and travel time for electric buses.« less

Design of a High Speed Data Capture Device for a Coherent Radar Application

DTIC Science & Technology

2006-11-01

of the RGASM is discussed, then the primary differences between coherent and non-coherent processing are compared. A basic digital receiver is then...IPP. 19 In-Phase Data Transfer Quadrature Data Transfer Label: Fuction : IQ-Sel Signifies whether data present on the bus is In-Phase or Quadrature...430S_IIZ _ l -.. t....!.... Label: Fuction : ADRS 16-bit address bus value DATA Actual 16-bit value of the data on the bus BUSEN* Bus enable READY* Bus

Workshop on Scientific Analysis and Policy in Network Security

DTIC Science & Technology

2010-09-10

IBBT Dcpt. Electrical Engineering-ESAT/COSlC. Kasteelpark Arenberg 10 Bus 2446, B-3001 Leuven. Belgium bart.preneelflesat.kuleuven.be Abstract. This...Bouissou1,3 1 Electricity de France R&D, 1 avenue du General de Gaulle, 92141 Clamart, France 2 Institut Telecom, Telecom ParisTech, 46 rue Barrault...for any x G Aj1; /, !,_0(x) is a probability distribution on AQ, such that if x G S{i then £jeS, (/’.^(.OXj) = L illul if x e Dii > then £j

Study of intelligent building system based on the internet of things

NASA Astrophysics Data System (ADS)

Wan, Liyong; Xu, Renbo

2017-03-01

In accordance with the problem such as isolated subsystems, weak system linkage and expansibility of the bus type buildings management system, this paper based on the modern intelligent buildings has studied some related technologies of the intelligent buildings and internet of things, and designed system architecture of the intelligent buildings based on the Internet of Things. Meanwhile, this paper has also analyzed wireless networking modes, wireless communication protocol and wireless routing protocol of the intelligent buildings based on the Internet of Things.

Development of Genuine Neural Network Prototype Chip

DTIC Science & Technology

1991-01-28

priori distribution is equivalent, and more readily visualized with a rank curve . The sonar signal data consisted of approximately 85% class Target and...15% class Clutter. For this reason, the rank curves for the class Clutter were used for device parameter analysis. R & D STATUS REPORT 1/28/91 N00014...the signal CLASSLD#. Four 10-bit class probabilities are available on the output bus (C0-C9, C16-C25, C32-C41 and C48- C57 ) at each clock cycle. A

Provision of Ubiquitous Tourist Information in Public Transport Networks

PubMed Central

García, Carmelo R.; Pérez, Ricardo; Alayón, Francisco; Quesada-Arencibia, Alexis; Padrón, Gabino

2012-01-01

This paper outlines an information system for tourists using collective public transport based on mobile devices with limited computation and wireless connection capacities. In this system, the mobile device collaborates with the vehicle infrastructure in order to provide the user with multimedia (visual and audio) information about his/her trip. The information delivered, adapted to the user preferences, is synchronized with the passage of vehicles through points of interest along the route, for example: bus stops, tourist sights, public service centres, etc.

A series of small scientific satellite with flexible standard bus

NASA Astrophysics Data System (ADS)

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

2009-11-01

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

A Versatile Image Processor For Digital Diagnostic Imaging And Its Application In Computed Radiography

NASA Astrophysics Data System (ADS)

Blume, H.; Alexandru, R.; Applegate, R.; Giordano, T.; Kamiya, K.; Kresina, R.

1986-06-01

In a digital diagnostic imaging department, the majority of operations for handling and processing of images can be grouped into a small set of basic operations, such as image data buffering and storage, image processing and analysis, image display, image data transmission and image data compression. These operations occur in almost all nodes of the diagnostic imaging communications network of the department. An image processor architecture was developed in which each of these functions has been mapped into hardware and software modules. The modular approach has advantages in terms of economics, service, expandability and upgradeability. The architectural design is based on the principles of hierarchical functionality, distributed and parallel processing and aims at real time response. Parallel processing and real time response is facilitated in part by a dual bus system: a VME control bus and a high speed image data bus, consisting of 8 independent parallel 16-bit busses, capable of handling combined up to 144 MBytes/sec. The presented image processor is versatile enough to meet the video rate processing needs of digital subtraction angiography, the large pixel matrix processing requirements of static projection radiography, or the broad range of manipulation and display needs of a multi-modality diagnostic work station. Several hardware modules are described in detail. For illustrating the capabilities of the image processor, processed 2000 x 2000 pixel computed radiographs are shown and estimated computation times for executing the processing opera-tions are presented.

The Association between Access to Public Transportation and Self-Reported Active Commuting

PubMed Central

Djurhuus, Sune; Hansen, Henning S.; Aadahl, Mette; Glümer, Charlotte

2014-01-01

Active commuting provides routine-based regular physical activity which can reduce the risk of chronic diseases. Using public transportation involves some walking or cycling to a transit stop, transfers and a walk to the end location and users of public transportation have been found to accumulate more moderate physical activity than non-users. Understanding how public transportation characteristics are associated with active transportation is thus important from a public health perspective. This study examines the associations between objective measures of access to public transportation and self-reported active commuting. Self-reported time spent either walking or cycling commuting each day and the distance to workplace were obtained for adults aged 16 to 65 in the Danish National Health Survey 2010 (n = 28,928). Access to public transportation measures were computed by combining GIS-based road network distances from home address to public transit stops an integrating their service level. Multilevel logistic regression was used to examine the association between access to public transportation measures and active commuting. Distance to bus stop, density of bus stops, and number of transport modes were all positively associated with being an active commuter and with meeting recommendations of physical activity. No significant association was found between bus services at the nearest stop and active commuting. The results highlight the importance of including detailed measurements of access to public transit in order to identify the characteristics that facilitate the use of public transportation and active commuting. PMID:25489998

The association between access to public transportation and self-reported active commuting.

PubMed

Djurhuus, Sune; Hansen, Henning S; Aadahl, Mette; Glümer, Charlotte

2014-12-05

Active commuting provides routine-based regular physical activity which can reduce the risk of chronic diseases. Using public transportation involves some walking or cycling to a transit stop, transfers and a walk to the end location and users of public transportation have been found to accumulate more moderate physical activity than non-users. Understanding how public transportation characteristics are associated with active transportation is thus important from a public health perspective. This study examines the associations between objective measures of access to public transportation and self-reported active commuting. Self-reported time spent either walking or cycling commuting each day and the distance to workplace were obtained for adults aged 16 to 65 in the Danish National Health Survey 2010 (n = 28,928). Access to public transportation measures were computed by combining GIS-based road network distances from home address to public transit stops an integrating their service level. Multilevel logistic regression was used to examine the association between access to public transportation measures and active commuting. Distance to bus stop, density of bus stops, and number of transport modes were all positively associated with being an active commuter and with meeting recommendations of physical activity. No significant association was found between bus services at the nearest stop and active commuting. The results highlight the importance of including detailed measurements of access to public transit in order to identify the characteristics that facilitate the use of public transportation and active commuting.

Design of a Mobile Low-Cost Sensor Network Using Urban Buses for Real-Time Ubiquitous Noise Monitoring.

PubMed

Alsina-Pagès, Rosa Ma; Hernandez-Jayo, Unai; Alías, Francesc; Angulo, Ignacio

2016-12-29

One of the main priorities of smart cities is improving the quality of life of their inhabitants. Traffic noise is one of the pollutant sources that causes a negative impact on the quality of life of citizens, which is gaining attention among authorities. The European Commission has promoted the Environmental Noise Directive 2002/49/EC (END) to inform citizens and to prevent the harmful effects of noise exposure. The measure of acoustic levels using noise maps is a strategic issue in the END action plan. Noise maps are typically calculated by computing the average noise during one year and updated every five years. Hence, the implementation of dynamic noise mapping systems could lead to short-term plan actions, besides helping to better understand the evolution of noise levels along time. Recently, some projects have started the monitoring of noise levels in urban areas by means of acoustic sensor networks settled in strategic locations across the city, while others have taken advantage of collaborative citizen sensing mobile applications. In this paper, we describe the design of an acoustic low-cost sensor network installed on public buses to measure the traffic noise in the city in real time. Moreover, the challenges that a ubiquitous bus acoustic measurement system entails are enumerated and discussed. Specifically, the analysis takes into account the feature extraction of the audio signal, the identification and separation of the road traffic noise from urban traffic noise, the hardware platform to measure and process the acoustic signal, the connectivity between the several nodes of the acoustic sensor network to store the data and, finally, the noise maps' generation process. The implementation and evaluation of the proposal in a real-life scenario is left for future work.

Design of a Mobile Low-Cost Sensor Network Using Urban Buses for Real-Time Ubiquitous Noise Monitoring

PubMed Central

Alsina-Pagès, Rosa Ma; Hernandez-Jayo, Unai; Alías, Francesc; Angulo, Ignacio

2016-01-01

One of the main priorities of smart cities is improving the quality of life of their inhabitants. Traffic noise is one of the pollutant sources that causes a negative impact on the quality of life of citizens, which is gaining attention among authorities. The European Commission has promoted the Environmental Noise Directive 2002/49/EC (END) to inform citizens and to prevent the harmful effects of noise exposure. The measure of acoustic levels using noise maps is a strategic issue in the END action plan. Noise maps are typically calculated by computing the average noise during one year and updated every five years. Hence, the implementation of dynamic noise mapping systems could lead to short-term plan actions, besides helping to better understand the evolution of noise levels along time. Recently, some projects have started the monitoring of noise levels in urban areas by means of acoustic sensor networks settled in strategic locations across the city, while others have taken advantage of collaborative citizen sensing mobile applications. In this paper, we describe the design of an acoustic low-cost sensor network installed on public buses to measure the traffic noise in the city in real time. Moreover, the challenges that a ubiquitous bus acoustic measurement system entails are enumerated and discussed. Specifically, the analysis takes into account the feature extraction of the audio signal, the identification and separation of the road traffic noise from urban traffic noise, the hardware platform to measure and process the acoustic signal, the connectivity between the several nodes of the acoustic sensor network to store the data and, finally, the noise maps’ generation process. The implementation and evaluation of the proposal in a real-life scenario is left for future work. PMID:28036065

A software bus for thread objects

NASA Technical Reports Server (NTRS)

Callahan, John R.; Li, Dehuai

1995-01-01

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

MIL-STD-1553 dynamic bus controller/remote terminal hybrid set

NASA Astrophysics Data System (ADS)

Friedman, S. N.

This paper describes the performance, physical and electrical requirements of a Dual Redundant BUS Interface Unit (BIU) acting as a BUS Controller Interface Unit (BCIU) or Remote Terminal Unit (RTU) between a Motorola 68000 VME BUS and MIL-STD-1553B Multiplex Data Bus. A discussion of how the BIU Hybrid set is programmed, and operates as a BCIU or RTU, will be included. This paper will review Dynamic Bus Control and other Mode Code capabilities. The BIU Hybrid Set interfaces to a 68000 Microprocessor with a VME Bus using programmed I/O transfers. This special interface will be discussed along with the internal Dual Access Memory (4K x 16) used to support the data exchanges between the CPU and the BIU Hybrid Set. The hybrid set's physical size and power requirements will be covered. This includes the present Double Eurocard the BIU function is presently being offered on.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Lijuan; Gonder, Jeff; Burton, Evan

This study evaluates the costs and benefits associated with the use of a stationary-wireless- power-transfer-enabled plug-in hybrid electric bus and determines the cost effectiveness relative to a conventional bus and a hybrid electric bus. A sensitivity sweep was performed over many different battery sizes, charging power levels, and number/location of bus stop charging stations. The net present cost was calculated for each vehicle design and provided the basis for design evaluation. In all cases, given the assumed economic conditions, the conventional bus achieved the lowest net present cost while the optimal plug-in hybrid electric bus scenario beat out the hybridmore » electric comparison scenario. The study also performed parameter sensitivity analysis under favorable and high unfavorable market penetration assumptions. The analysis identifies fuel saving opportunities with plug-in hybrid electric bus scenarios at cumulative net present costs not too dissimilar from those for conventional buses.« less

Bus use and older people: a literature review applying the Person-Environment-Occupation model in macro practice.

PubMed

Broome, Kieran; McKenna, Kryss; Fleming, Jennifer; Worrall, Linda

2009-03-01

The same reasons that prompt older people to give up driving can also result in difficulties with accessing public transport. Difficulties using public transport can limit older people's participation in society, thereby impacting negatively on their health. Focusing on public buses, this review explicates the link between bus usability and the health of older people and frames existing evidence on bus usability issues. The Person-Environment-Occupation (PEO) model offers a framework by which bus usability can be assessed. A combination of person-centred, environmental, and occupation-related factors, including bus design, service provision and performance, information, and the attitudes of staff and the community, impact on older people's ability to catch buses. More systematic research needs to take place in order to develop a comprehensive understanding of bus usability. Occupational therapy has a key role to play in conceptualizing, implementing, and evaluating improvements in bus usability for older people.

Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC

NASA Technical Reports Server (NTRS)

1999-01-01

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

75 FR 5847 - Section 5309 Bus and Bus Facilities Livability Initiative and Urban Circulator Program Grants

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-04

... Livability Initiative and Urban Circulator Program Grants AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice to Extend Application Deadline for the Bus and Bus Facilities and Urban Circulator..., Transportation Equity Act: A Legacy for Users (SAFETEA-LU), Public Law 109-59, August 10, 2005. The Urban...

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

ERIC Educational Resources Information Center

Fox, Michael

1995-01-01

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

School Bus Safety: What Can Our Schools Do to Protect Our Children?

ERIC Educational Resources Information Center

Dargan, Thomas J.; Silverstone, Adam H.

2014-01-01

School districts and school bus contractors are entrusted with the most important of all road users--our nation's children. In the wake of recent newsworthy accidents and attention grabbing headlines regarding unfit bus drivers, claims premised upon school bus accidents have become increasingly tangential and, in turn, personal injury attorneys…

49 CFR 383.123 - Requirements for a school bus endorsement.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 5 2011-10-01 2011-10-01 false Requirements for a school bus endorsement. 383.123... Requirements for a school bus endorsement. (a) An applicant for the school bus endorsement must satisfy the... for school buses by State or Federal law or regulation. (ii) Emergency exits and procedures for safely...