Buses of Cuernavaca—an agent-based model for universal random matrix behavior minimizing mutual information

NASA Astrophysics Data System (ADS)

Warchoł, Piotr

2018-06-01

The public transportation system of Cuernavaca, Mexico, exhibits random matrix theory statistics. In particular, the fluctuation of times between the arrival of buses on a given bus stop, follows the Wigner surmise for the Gaussian unitary ensemble. To model this, we propose an agent-based approach in which each bus driver tries to optimize his arrival time to the next stop with respect to an estimated arrival time of his predecessor. We choose a particular form of the associated utility function and recover the appropriate distribution in numerical experiments for a certain value of the only parameter of the model. We then investigate whether this value of the parameter is otherwise distinguished within an information theoretic approach and give numerical evidence that indeed it is associated with a minimum of averaged pairwise mutual information.

Objectification of Public Bus Stop's Pavement Surface Morphology

NASA Astrophysics Data System (ADS)

Decký, Martin; Kováč, Matúš; Mužík, Juraj; Mičechová, Lenka; Ďuriš, Lukáš

2018-06-01

The article deals with the road pavement surface morphology objectification in term of the surface unevenness degradation during the life cycle of bus stop pavements. The article presents the results of long-term rut depth measurements performed during 25 years on selected bus stops which were intended to determine correlation dependences of pavement rut depth on a number of design axles. The article also presents different methods for rut depth measurements including the straightedge test, Profilograph GE, TRIMBLE CX, and dynamic Road Scanner.

Individual and population intake fractions of diesel particulate matter (DPM) in bus stop microenvironments.

PubMed

Xu, Jia; Jin, Taosheng; Miao, Yaning; Han, Bin; Gao, Jiajia; Bai, Zhipeng; Xu, Xiaohong

2015-12-01

Diesel particulate matter (DPM) is associated with adverse human health effects. This study aims to investigate the relationship between DPM exposure and emissions by estimating the individual intake fraction (iFi) and population intake fraction (iFp) of DPM. Daily average concentrations of particulate matter at two bus stops during rush hours were measured, and then they were apportioned to DPM due to heavy-duty diesel bus emissions using Chemical Mass Balance Model. The DPM emissions of diesel buses for different driving conditions (idling, creeping and traveling) were estimated on the basis of field observations and published emission factors. The median iFi of DPM was 0.67 and 1.39 per million for commuters standing at the bus stop and pedestrians/cyclists passing through the bus stop during rush hours, respectively. The median iFp of DPM was 94 per million. Estimations of iFi and iFp of DPM are potentially significant for exposure assessment and risk management. Copyright © 2015 Elsevier Ltd. All rights reserved.

IMPACTS OF BUS STOP IMPROVEMENTS

DOT National Transportation Integrated Search

2018-03-23

Improving bus stops by providing shelters, seating, signage, and sidewalks is relatively inexpensive and popular among riders and local officials. Making such improvements, however, is not often a priority for U.S. transit providers because of compet...

Efficiency in bus stop location and design.

DOT National Transportation Integrated Search

1980-01-01

The research reported here identified those elements associated with the location and design of bus stops that affect the efficiency of transit and traffic operations, and developed guidelines to assist transportation engineers and planners in techni...

Transit bus stop pedestrian warning application : requirements document.

DOT National Transportation Integrated Search

2016-08-01

This document describes the System Requirements for the Transit Bus Stop Pedestrian Warning (TSPW) application. The requirements describe the system of interest for the implementation team including the required functions and performance along with t...

Final Environmental Assessment (EA) for the Revitalization of Military Family Housing Keesler AFB, MS

DTIC Science & Technology

2006-03-01

12,000 square feet each). An Olympic-size swimming pool (approximately 71 feet by 164 feet). Twelve covered bus stops. A skateboard park...11,644 Covered Bus Stop 100 12 1,200 Skateboard Park 10,890 1 10,890 Storage Unit 100 534 53,400 Total N/A N/A 125,134 Location to be determined...Olympic-size Swimming Pool 1 1 Covered Bus Stop 5 4 3 12 Skateboard Park 1 1 Storage Unit 0 294 160 80 534 2.6 ALTERNATIVE 1 (IMMEDIATE

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.

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.

Transit bus stop pedestrian warning application : acceptance test plan : final report.

DOT National Transportation Integrated Search

2016-10-14

This document is the Acceptance Test Plan for the Transit Bus Stop Pedestrian Warning (TSPW) application. This report describes the test and demonstration plan to verify that the application meets its functional and performance requirements.

Transit bus stop pedestrian warning application : concept of operations document.

DOT National Transportation Integrated Search

2015-02-04

This document describes the Concept of Operations (ConOps) for the Transit Bus Stop Pedestrian Warning (TSPW) application. The ConOps describes the current state of operations with respect to the integration of connected vehicle technology in transit...

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 ...

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.

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

Motorist Comprehension of Florida's School Bus Stop Law and School Bus Signalization Devices

DOT National Transportation Integrated Search

1997-06-01

In May 1995, the Center for Urban Transportation Research (CUTR) conducted a study on behalf of the Florida Department of Education (DOE) that investigated the frequency and extent with which drivers in Florida were illegally passing stopped school b...

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...

The role of a bus network in access to primary health care in Metropolitan Auckland, New Zealand.

PubMed

Rocha, C M; McGuire, S; Whyman, R; Kruger, E; Tennant, M

2015-09-01

Background: This study examined the spatial accessibility of the population of metropolitan Auckland, New Zealand to the bus network, to connect them to primary health providers, in this case doctors (GP) and dentists. Analysis of accessibility by ethnic identity and socio-economic status were also carried out, because of existing health inequalities along these dimensions. The underlying hypothesis was that most people would live within easy reach of primary health providers, or easy bus transport to such providers. An integrated geographic model of bus transport routes and stops, with population and primary health providers (medical. and dental practices) was developed and analysed. Although the network of buses in metropolitan Auckland is substantial and robust it was evident that many people live more than 150 metres from a stop. Improving the access to bus stops, particularly in areas of high primary health care need (doctors and dentists), would certainly be an opportunity to enhance spatial access in a growing metropolitan area.

Cost Effectiveness Analysis of Quasi-In-Motion Wireless Power Transfer for Plug-In Hybrid Electric Transit Buses from Fleet Perspective

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

Wang, Lijuan; Gonder, Jeff; Brooker, Aaron

This study evaluated the costs and benefits associated with the use of stationary-wireless-power-transfer-enabled plug-in hybrid electric buses and determined the cost effectiveness relative to conventional buses and hybrid electric buses. A factorial design was performed over a number of different battery sizes, charging power levels, and f bus stop charging stations. The net present costs were 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 hybrid electric comparison scenario.more » The parameter sensitivity was also investigated under favorable and unfavorable market penetration assumptions.« less

1. VIEW, LOOKING SOUTH, OF THE NORTH ELEVATION OF BUILDING ...

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

1. VIEW, LOOKING SOUTH, OF THE NORTH ELEVATION OF BUILDING 114. BUILDING 114 SERVED AS THE BUS STOP SHELTER WHEN PERSONAL VEHICLES WERE BANNED ON THE SITE PROPERTY. - Rocky Flats Plant, Bus Stop Shelter, West side of Fourth Street, south of Central Avenue, Golden, Jefferson County, CO

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…

The Bus Stops Here.

ERIC Educational Resources Information Center

Milshtein, Amy

1999-01-01

Explores some of the factors to consider before school planners decide to buy new school buses. Provides a checklist to help build and maintain a bus fleet. Concludes by addressing bus safety and advertising. (GR)

Pilot survey of subway and bus stop noise levels.

PubMed

Gershon, Robyn R M; Neitzel, Richard; Barrera, Marissa A; Akram, Muhammad

2006-09-01

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

214. RUSTIC BUS SHELTER, GUARDRAILS AND LAMP POST BELLE HAVEN ...

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

214. RUSTIC BUS SHELTER, GUARDRAILS AND LAMP POST BELLE HAVEN BUS STOP WIDENING, 1932. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

Influence of bus stop with left-turn lines between two adjacent signalized intersections

NASA Astrophysics Data System (ADS)

Pang, Ming-Bao; Ye, Lan-Hang; Pei, Ya-Nan

2016-08-01

Based on the symmetric two-lane Nagel-Schreckenberg (STNS) model, a three-lane cellular automaton model between two intersections containing a bus stop with left-turning buses is established in which model the occurrences of vehicle accidents are taken into account. The characteristics of traffic flows with different ratios of left-turn lines are discussed via the simulation experiments. The results indicate that the left-turn lines have more negative effects on capacity, accident rate as well as delay if the stop is located close to the intersections, where the negative effect in a near-side stop is more severe than that in a far-side one. The range of appropriate position for a bus stop without the bottleneck effect becomes more and more narrow with the increase of the ratio of left-turn bus lines. When the inflow is small, a short signal cycle and a reasonable offset are beneficial. When the inflow reaches or exceeds the capacity, a longer signal cycle is helpful. But if the stop position is inappropriate, the increase of cycle fails in reducing the negative effect of left-turning buses and the effectiveness of offset is weakened. Project supported by the National Natural Science Foundation of China (Grant No. 50478088) and the Natural Science Foundation of Hebei Province, China (Grant No. E2015202266).

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...

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.

Pilot Survey of Subway and Bus Stop Noise Levels

PubMed Central

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

2006-01-01

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

Integration of bus stop counts data with census data for improving bus service.

DOT National Transportation Integrated Search

2016-04-01

This research project produced an open source transit market data visualization and analysis tool suite, : The Bus Transit Market Analyst (BTMA), which contains user-friendly GIS mapping and data : analytics tools, and state-of-the-art transit demand...

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.

Optimation of Operation System Integration between Main and Feeder Public Transport (Case Study: Trans Jakarta-Kopaja Bus Services)

NASA Astrophysics Data System (ADS)

Miharja, M.; Priadi, Y. N.

2018-05-01

Promoting a better public transport is a key strategy to cope with urban transport problems which are mostly caused by a huge private vehicle usage. A better public transport service quality not only focuses on one type of public transport mode, but also concerns on inter modes service integration. Fragmented inter mode public transport service leads to a longer trip chain as well as average travel time which would result in its failure to compete with a private vehicle. This paper examines the optimation process of operation system integration between Trans Jakarta Bus as the main public transport mode and Kopaja Bus as feeder public transport service in Jakarta. Using scoring-interview method combined with standard parameters in operation system integration, this paper identifies the key factors that determine the success of the two public transport operation system integrations. The study found that some key integration parameters, such as the cancellation of “system setoran”, passenger get in-get out at official stop points, and systematic payment, positively contribute to a better service integration. However, some parameters such as fine system, time and changing point reliability, and information system reliability are among those which need improvement. These findings are very useful for the authority to set the right strategy to improve operation system integration between Trans Jakarta and Kopaja Bus services.

Complexity analysis on public transport networks of 97 large- and medium-sized cities in China

NASA Astrophysics Data System (ADS)

Tian, Zhanwei; Zhang, Zhuo; Wang, Hongfei; Ma, Li

2018-04-01

The traffic situation in Chinese urban areas is continuing to deteriorate. To make a better planning and designing of the public transport system, it is necessary to make profound research on the structure of urban public transport networks (PTNs). We investigate 97 large- and medium-sized cities’ PTNs in China, construct three types of network models — bus stop network, bus transit network and bus line network, then analyze the structural characteristics of them. It is revealed that bus stop network is small-world and scale-free, bus transit network and bus line network are both small-world. Betweenness centrality of each city’s PTN shows similar distribution pattern, although these networks’ size is various. When classifying cities according to the characteristics of PTNs or economic development level, the results are similar. It means that the development of cities’ economy and transport network has a strong correlation, PTN expands in a certain model with the development of economy.

Evolutionary algorithm for vehicle driving cycle generation.

PubMed

Perhinschi, Mario G; Marlowe, Christopher; Tamayo, Sergio; Tu, Jun; Wayne, W Scott

2011-09-01

Modeling transit bus emissions and fuel economy requires a large amount of experimental data over wide ranges of operational conditions. Chassis dynamometer tests are typically performed using representative driving cycles defined based on vehicle instantaneous speed as sequences of "microtrips", which are intervals between consecutive vehicle stops. Overall significant parameters of the driving cycle, such as average speed, stops per mile, kinetic intensity, and others, are used as independent variables in the modeling process. Performing tests at all the necessary combinations of parameters is expensive and time consuming. In this paper, a methodology is proposed for building driving cycles at prescribed independent variable values using experimental data through the concatenation of "microtrips" isolated from a limited number of standard chassis dynamometer test cycles. The selection of the adequate "microtrips" is achieved through a customized evolutionary algorithm. The genetic representation uses microtrip definitions as genes. Specific mutation, crossover, and karyotype alteration operators have been defined. The Roulette-Wheel selection technique with elitist strategy drives the optimization process, which consists of minimizing the errors to desired overall cycle parameters. This utility is part of the Integrated Bus Information System developed at West Virginia University.

Computer-Based Video Instruction to Teach Students with Intellectual Disabilities to Use Public Bus Transportation

ERIC Educational Resources Information Center

Mechling, Linda; O'Brien, Eileen

2010-01-01

This study investigated the effectiveness of computer-based video instruction (CBVI) to teach three young adults with moderate intellectual disabilities to push a "request to stop bus signal" and exit a city bus in response to target landmarks. A multiple probe design across three students and one bus route was used to evaluate effectiveness of…

Recommendations for yield-to-bus traffic control devices and bus pullout bays design characteristics.

DOT National Transportation Integrated Search

2013-04-01

Traffic control devices such as roadside signs and pavement markings are used to promote highway safety and efficiency for all road users. A bus pullout bay is a special geometric roadway feature that allows transit buses to stop outside the travel l...

Highway Accident Summary Report: Bus Collision With Pedestrians, Normandy, Missouri, June 11, 1997

DOT National Transportation Integrated Search

1998-02-19

On June 11, 1997, a transit bus collided with seven pedestrians at a "park and ride" transit facility in Normandy, Missouri. The bus was being operated by a driver trainee who had just completed a routine stop at the station. After allowing the passe...

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.

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.

Performance Analysis of Trans-Jakarta Bus Suburban Service Move-Across Greater Jakarta

NASA Astrophysics Data System (ADS)

Tangkudung, ESW; Widyadayinta, C.

2018-03-01

Trans-Jakarta have developed their services scope as Suburban Service or Feeder move-across service that operate from greater Jakarta into Jakarta central vice versa. One of the route is Ciputat – Bundaran Hotel Indonesia (Tosari) and integrated with corridor 1 (one) and 8 (eight). This service is not travel on the exclusive lane or bus-way. Objective of Government Jakarta to provide this service is to decrease private car to enter the central of Jakarta. The objective of this study is to find the performance of the service. Survey have conducted static and dynamic on work day to get variable of travel time and delay, waiting time of passenger at the bus stop, headway and ridership of the bus. Service Standard Minimum of Trans-Jakarta have compared with the result of variable headway, travel speed, and waiting time at bus stop as concern of all the passengers. Analysis use correlation test method and linear regression model have done. The performance of Trans-Jakarta bus suburban service, based on travel speed indicator is fairly bad, only 8.1% of trip could comply with Minimum Service Standard. Bus performance based on the indicator of density in the bus is good, where all points are below the maximum limit i.e. 8 people/m2 at peak hour and 5 people/m2 at off-peak hour.

3 Ways that Web-Based Computing Will Change Colleges--And Challenge Them

ERIC Educational Resources Information Center

Young, Jeffrey R.

2008-01-01

Cloud computing, one of the latest technology buzzwords, is so hard to explain that Google drove a bus from campus to campus to walk students through the company's vision of it. After students sat through a demo at computers set up nearby, they boarded the bus and got free T-shirts. The bus only stopped at colleges that had already agreed to hand…

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.

Guidelines for bus transit stops in highway construction work zones.

DOT National Transportation Integrated Search

2014-12-01

Fixed route transit systems provide a valuable transportation service for many of our citizens. As users depend on : bus transit to access to the essentials of life, maintaining transit service is a critical issue. Given the extent of : nationwide bu...

Evaluation of bus transit reliability in the District of Columbia.

DOT National Transportation Integrated Search

2013-11-01

Several performance metrics can be used to assess the reliability of a transit system. These include on-time arrivals, travel-time : adherence, run-time adherence, and customer satisfaction, among others. On-time arrival at bus stops is one of the pe...

Safer stops for vulnerable customers

DOT National Transportation Integrated Search

2003-03-01

This synthesis report presents a brief synopsis of the current literature and technologies being used in the development of safer and more secure bus stops. While the focus is more specifically with regard to vulnerable populations - women, children,...

Parameterizing Sound: Design Considerations for an Environmental Sound Database

DTIC Science & Technology

2015-04-01

Accordion Car backfire Crushing a metal can Aerosol can Car crash Crushing a tin can Alarm clock Car ignition Crushing egg shells Alloette...top Coffee perking Eggs beaten in a bowl with a whisk Bowling Coffee pot whistling Elastic (snap) Bread cutting Coin dropping Electric...Bus Combination lock Female speaking Bus air break Cooking with fat Ferry Bus stop and go Cuckoo clock Ferry horn Camera Corduroy

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%.

School bus’s level of service in Malang City

NASA Astrophysics Data System (ADS)

Hariyani, S.

2017-06-01

School Bus began operated on the 12th of January 2015. Provision of school buses is expected to reduce not only the use of vehicles by students, but it is also to reduce the number of traffic jams. Malang school bus facilities provided by the Department of Transport in cooperation with the Department of Education to serve students in elementary school, junior and senior high schools. After the service running two years, based on the preliminary observation not all students are interested in using the school bus. The research objective was to measure the school bus’s level service. The method to measure school bus’s level of service was used Importance Performance analysis (IPA). The results showed that through IPA, it can be concluded that school bus’s level of service in Malang City have been able to serve students/customers with the mean of degree suitability (Tki) is 111. Meanwhile it must be observed and get more attention to improve by government, attributes which is lies in the first quadrant or concentrate here (attribute Adequate space, Seating capacity, Availability trash can, Passenger facility down in points, The availability of information boards in each bus stop, Availability public telephone in each bus stop, and Availability CCTV in each bus), in order to increase its performance.

Evaluating the attractiveness of a new light rail extension: Testing simple change and displacement change hypotheses

PubMed Central

Brown, Barbara B.; Tribby, Calvin P.; Tharp, Doug; Flick, Kristi; Miller, Harvey J.; Smith, Ken R.; Jensen, Wyatt

2015-01-01

Many communities in the United States have been adding new light rail to bus-predominant public transit systems. However, there is disagreement as to whether opening light rail lines attracts new ridership or merely draws ridership from existing transit users. We study a new light rail line in Salt Lake City, Utah, USA, which is part of a complete street redevelopment. We utilize a pre-test post-test control group quasi-experimental design to test two different measures of ridership change. The first measure is calculated from stops along the light rail route; the second assumes that nearby bus stops might be displaced by the rail and calculates ridership change with those stops included as baseline. Both the simple measure (transit use changes on the complete street light rail corridor) and the “displacement” measure (transit use changes in the one-quarter mile catchment areas around new light rail stops) showed significant (p < .01) and substantial (677%) increases in transit passengers compared to pre-light rail bus users. In particular, the displacement analysis discredits a common challenge that when a new light rail line opens, most passengers are simply former bus riders whose routes were canceled in favor of light rail. The study suggests that light rail services can attract additional ridership to public transit systems. In addition, although pre-post control-group designs require time and effort, this project underscores the benefits of such quasi-experimental designs in terms of the strength of the inferences that can be drawn about the impacts of new transit infrastructure and services. PMID:26543329

Evaluating the attractiveness of a new light rail extension: Testing simple change and displacement change hypotheses.

PubMed

Werner, Carol M; Brown, Barbara B; Tribby, Calvin P; Tharp, Doug; Flick, Kristi; Miller, Harvey J; Smith, Ken R; Jensen, Wyatt

2016-01-01

Many communities in the United States have been adding new light rail to bus-predominant public transit systems. However, there is disagreement as to whether opening light rail lines attracts new ridership or merely draws ridership from existing transit users. We study a new light rail line in Salt Lake City, Utah, USA, which is part of a complete street redevelopment. We utilize a pre-test post-test control group quasi-experimental design to test two different measures of ridership change. The first measure is calculated from stops along the light rail route; the second assumes that nearby bus stops might be displaced by the rail and calculates ridership change with those stops included as baseline. Both the simple measure (transit use changes on the complete street light rail corridor) and the "displacement" measure (transit use changes in the one-quarter mile catchment areas around new light rail stops) showed significant ( p < .01) and substantial (677%) increases in transit passengers compared to pre-light rail bus users. In particular, the displacement analysis discredits a common challenge that when a new light rail line opens, most passengers are simply former bus riders whose routes were canceled in favor of light rail. The study suggests that light rail services can attract additional ridership to public transit systems. In addition, although pre-post control-group designs require time and effort, this project underscores the benefits of such quasi-experimental designs in terms of the strength of the inferences that can be drawn about the impacts of new transit infrastructure and services.

Assessing Liability and Legitimacy of School Transportation Services

ERIC Educational Resources Information Center

Ammon, Tim; Burns, Peggy

2011-01-01

Whenever a school district considers changing bus stops, bus routes, or bell times, the public reaction is often decidedly unequal to the magnitude of the changes proposed. Unfortunately, the severity of continued budget crises has compelled many school districts to make major changes to their transportation systems. While additional cuts in…

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.

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.

Impact of Transit Stop Location on Pedestrian Safety [Final Report

DOT National Transportation Integrated Search

2017-10-30

This research involved a GIS analysis of pedestrian crashes that occurred within 100 feet of bus stops in Broward County and Palm Beach County, Florida between 2011 and 2014. There were 357 such pedestrian crashes in Broward County and 221 in Palm Be...

Mapping Between Bus Rapid Transit Shelter and High School Location in Semarang

NASA Astrophysics Data System (ADS)

Dewi, D. I. K.; Rakhmatulloh, A. R.; Anggraini, P.

2018-02-01

The main users of public bus transport are those who have the goal to work and attend school. But the last few years there has been a decline in the use of public transport for high school students. Partly of the reason are the high use of motorcycle by student and lack of bus stop service range to high school location. This research has aim to increase the use of public transport for school students by mapping Bus Rapid Transit (BRT) shelter and school locations. The research method used are descriptive quantitative with GIs analysis tools and using spatial analysis approach

Highway/Railroad Accident Report: Collision Of Northeast Illinois Regional Commuter Railroad Corporation (METRA) Train And Transportation Joint Agreement School District 47/155 School Bus At Railroad/Highway Grade Crossing In Fox River Grove, Illinois, On

DOT National Transportation Integrated Search

1996-10-29

This report explains the collision of a Northeast Illinois Regional Commuter Railroad Corporation commuter train with a Transportation Joint Agreement School District 47/155 school bus that was stopped at a railroad/highway grade crossing in Fox Rive...

Stepping up Protection

ERIC Educational Resources Information Center

Kennedy, Mike

2006-01-01

As a school bus comes to a halt on a busy street, the driver swings out the vehicle's stop arm and turns on flashing red lights. Most drivers know what those signals mean--they are required by law to stop their vehicles so that children can safely cross the thoroughfare. However, many drivers simply choose to ignore the law. Thousands of…

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.

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.

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.

Remote infrared signage evaluation for transit stations and intersections.

PubMed

Crandall, W; Brabyn, J; Bentzen, B L; Myers, L

1999-10-01

Opportunities for education and employment depend upon effective and independent travel. For mainstream society, this is accomplished to a large extent by printed signs. People who are print disabled, visually impaired, or totally blind are at a disadvantage because they do not have access to signage. Remote infrared signage, such as the Talking Signs (TS) system, provides a solution to this need by labeling the environment for distant viewing. The system uses a transmitting "sign" and a hand-held receiver to tell people about their surroundings. In a seamless infrared signage environment, a visually impaired traveler could: walk safely across an intersection to an ATM or fare machine, from fare machine to bus stop, from bus stop to bus; from bus to building, from building to elevator, from elevator to office, from office to restroom, and so forth. This paper focuses on two problems that are among the most challenging and dangerous faced by blind travelers: negotiating complex transit stations and controlled intersections. We report on human factors studies of TS in these critical tasks, examining such issues as how much training is needed to use the system, its impact on performance and safety, benefits for different population subgroups and user opinions of its value. Results indicate that blind people can quickly and easily learn to use remote infrared signage effectively, and that its use improves travel safety, efficiency, and independence.

An Optimal Control Strategy for DC Bus Voltage Regulation in Photovoltaic System with Battery Energy Storage

PubMed Central

Daud, Muhamad Zalani; Mohamed, Azah; Hannan, M. A.

2014-01-01

This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV) system with battery energy storage (BES). The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way, the regulation of DC bus voltage of the PV/BES system can be enhanced as compared to the conventional regulation that is solely based on the voltage-sourced converter (VSC). For the grid side VSC (G-VSC), two control methods, namely, the voltage-mode and current-mode controls, are applied. For control parameter optimization, the simplex optimization technique is applied for the G-VSC voltage- and current-mode controls, including the BES DC/DC buck-boost converter controllers. A new set of optimized parameters are obtained for each of the power converters for comparison purposes. The PSCAD/EMTDC-based simulation case studies are presented to evaluate the performance of the proposed optimized control scheme in comparison to the conventional methods. PMID:24883374

An optimal control strategy for DC bus voltage regulation in photovoltaic system with battery energy storage.

PubMed

Daud, Muhamad Zalani; Mohamed, Azah; Hannan, M A

2014-01-01

This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV) system with battery energy storage (BES). The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way, the regulation of DC bus voltage of the PV/BES system can be enhanced as compared to the conventional regulation that is solely based on the voltage-sourced converter (VSC). For the grid side VSC (G-VSC), two control methods, namely, the voltage-mode and current-mode controls, are applied. For control parameter optimization, the simplex optimization technique is applied for the G-VSC voltage- and current-mode controls, including the BES DC/DC buck-boost converter controllers. A new set of optimized parameters are obtained for each of the power converters for comparison purposes. The PSCAD/EMTDC-based simulation case studies are presented to evaluate the performance of the proposed optimized control scheme in comparison to the conventional methods.

Determinants of spikes in ultrafine particle concentration whilst commuting by bus

NASA Astrophysics Data System (ADS)

Lim, Shanon; Dirks, Kim N.; Salmond, Jennifer A.; Xie, Shanju

2015-07-01

This paper examines concentration of ultrafine particles (UFPs) based on data collected using high-resolution UFP monitors whilst travelling by bus during rush hour along three different urban routes in Auckland, New Zealand. The factors influencing in-bus UFP concentration were assessed using a combination of spatial, statistical and GIS analysis techniques to determine both spatial and temporal variability. Results from 68 bus trips showed that concentrations varied more within a route than between on a given day, despite differences in urban morphology, land use and traffic densities between routes. A number of trips were characterised by periods of very rapid increases in UFPs (concentration 'spikes'), followed by slow declines. Trips which recorded at least one spike (an increase of greater than 10,000 pt/cm3) resulted in significantly higher mean concentrations. Spikes in UFPs were significantly more likely to occur when travelling at low speeds and when passengers were alighting and boarding at bus stops close to traffic light intersections.

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 ...

25 CFR 170.152 - What transit facilities and activities are eligible for IRR Program funding?

Code of Federal Regulations, 2014 CFR

2014-04-01

... INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Policy and... facilities that incorporate other community services; (h) Passenger shelters, bus stop signs, and similar...

25 CFR 170.152 - What transit facilities and activities are eligible for IRR Program funding?

Code of Federal Regulations, 2012 CFR

2012-04-01

... INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Policy and... facilities that incorporate other community services; (h) Passenger shelters, bus stop signs, and similar...

25 CFR 170.152 - What transit facilities and activities are eligible for IRR Program funding?

Code of Federal Regulations, 2013 CFR

2013-04-01

... INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Policy and... facilities that incorporate other community services; (h) Passenger shelters, bus stop signs, and similar...

25 CFR 170.152 - What transit facilities and activities are eligible for IRR Program funding?

Code of Federal Regulations, 2011 CFR

2011-04-01

... INTERIOR LAND AND WATER INDIAN RESERVATION ROADS PROGRAM Indian Reservation Roads Program Policy and... facilities that incorporate other community services; (h) Passenger shelters, bus stop signs, and similar...

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

Evaluation of the Salt Lake City Computerized Rider Information System

DOT National Transportation Integrated Search

1985-11-01

The Utah Transit Authority (UTA) Computerized Rider Information System (CRIS) project involved the installation of an automated telephone service to quickly provide bus stop-specific schedule and service information to residents throughout the Author...

Dirty breathing

NASA Astrophysics Data System (ADS)

Wisham, M.

2017-12-01

Breathing issues befall most asthmatics. However, the symptoms are not caused randomly. Particulate matter is a cause that has been collected and sampled at several bus stops. The following experiment provides the results of collected particulate matter in several locations around LSU.

Characterisation of an urban bus network for environmental purposes.

PubMed

André, Michel; Villanova, André

2004-12-01

Since pollutant emissions are closely related to the operating conditions of vehicles, their evaluation usually involves studying these operating conditions (through bus instrumentation and monitoring under actual operation), the design of representative driving or engine test cycles and the measurement of pollutant emissions. A preliminary characterisation of the routes on a bus network should make it possible to identify typical routes, the driving conditions and pollutant emissions of which are then studied. Two approaches are envisaged and applied to the Paris area, for which a wealth of information is available, which should be transferable to other bus networks. Both approaches are based on factorial analysis and automatic clustering, to allow optimum description and the identification of a pertinent typology of the bus routes in several classes. The first attempt at characterisation is based on statistics relating to bus operations: route characteristics (length, dedicated bus lanes, number of stops, location of stops: schools, tourist sites, hospitals, railways or underground stations), travel time, commercial speed, annual statistics (number of passengers, number of vehicles per hour, total kilometres), the irregularity of travel (variation of travel times, injuries, congestion.), as well as information on the problems encountered (congestion, distribution of the passenger load, junctions, bends). A second approach is based on the analysis of the "urban context" in which buses are driven. Population, employment, housing, road network, traffic and places that generate or disturb traffic (schools, railway stations, shopping areas, etc.) are calculated for the Ile de France region, by cells of 100 x 100 m, and collected in a geographical information system (GIS). Statistical analyses enable a typology of these urban cells to be established, the main parameters being density, type of housing, road types and traffic levels. The bus routes are then analysed according to their itineraries across these typical areas (distances travelled in each type of area) using a similar approach. A comparison of the typologies obtained from operational data and from urban data highlights the advantages and disadvantages of the two approaches. The first result from these typologies is the selection of routes which are representative of the different classes, in order to instrument buses and record driving patterns. This method should also make it possible to link driving conditions and urban characteristics, and then to allocate pollutant emission factors to given geographical situations, in particular, in the context of emission inventories or impact studies.

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.

Sudden illness while driving a vehicle--a retrospective analysis of commercial drivers in Japan.

PubMed

Hitosugi, Masahito; Gomei, Sayaka; Okubo, Takao; Tokudome, Shogo

2012-01-01

We performed a retrospective analysis of commercial drivers to clarify the background of incidents of sudden illness while driving. The analysis used reports submitted by employers to the Japan Ministry of Land, Infrastructure, Transport, and Tourism regarding commercial drivers who had been ordered to stop driving owing to health problems. Of 211 cases with an average work history of 15.2 years, there were 88 bus drivers, 70 taxi drivers, and 53 truck drivers, 36.0% of who had died as a result of their disease. Among taxi and truck drivers, more than 70% of incidents were due to cardiac, aortic, and cerebrovascular disease. More than 80% of these were unable to avoid traffic accidents caused by sudden illness. However, among bus drivers, cardiac, aortic, and cerebrovascular disease accounted for only 23.5% of incidents, and accidents were avoided in more than half of the cases. The duration between starting work and the incident time was significantly shorter among bus drivers [mean 3.3 hours, standard deviation (SD) 3.1] than taxi (7.7 hours, SD 5.8) and truck (7.2 hours, SD 6.3) drivers (P<0.01). The difference between the sudden illness rates of taxi and truck drivers and those of bus drivers is due to both reporting bias and differences in the awareness needed to prevent disabling events while driving. As a precaution, physicians should advise commercial drivers to stop driving as soon as they detect slight discomfort. To prevent accidents, more assertive health promotion aimed at professional drivers is needed.

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.

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

PubMed

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

2015-01-01

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

Fairness in optimizing bus-crew scheduling process.

PubMed

Ma, Jihui; Song, Cuiying; Ceder, Avishai Avi; Liu, Tao; Guan, Wei

2017-01-01

This work proposes a model considering fairness in the problem of crew scheduling for bus drivers (CSP-BD) using a hybrid ant-colony optimization (HACO) algorithm to solve it. The main contributions of this work are the following: (a) a valid approach for cases with a special cost structure and constraints considering the fairness of working time and idle time; (b) an improved algorithm incorporating Gamma heuristic function and selecting rules. The relationships of each cost are examined with ten bus lines collected from the Beijing Public Transport Holdings (Group) Co., Ltd., one of the largest bus transit companies in the world. It shows that unfair cost is indirectly related to common cost, fixed cost and extra cost and also the unfair cost approaches to common and fixed cost when its coefficient is twice of common cost coefficient. Furthermore, the longest time for the tested bus line with 1108 pieces, 74 blocks is less than 30 minutes. The results indicate that the HACO-based algorithm can be a feasible and efficient optimization technique for CSP-BD, especially with large scale problems.

Regular transport dynamics produce chaotic travel times.

PubMed

Villalobos, Jorge; Muñoz, Víctor; Rogan, José; Zarama, Roberto; Johnson, Neil F; Toledo, Benjamín; Valdivia, Juan Alejandro

2014-06-01

In the hope of making passenger travel times shorter and more reliable, many cities are introducing dedicated bus lanes (e.g., Bogota, London, Miami). Here we show that chaotic travel times are actually a natural consequence of individual bus function, and hence of public transport systems more generally, i.e., chaotic dynamics emerge even when the route is empty and straight, stops and lights are equidistant and regular, and loading times are negligible. More generally, our findings provide a novel example of chaotic dynamics emerging from a single object following Newton's laws of motion in a regularized one-dimensional system.

Regular transport dynamics produce chaotic travel times

NASA Astrophysics Data System (ADS)

Villalobos, Jorge; Muñoz, Víctor; Rogan, José; Zarama, Roberto; Johnson, Neil F.; Toledo, Benjamín; Valdivia, Juan Alejandro

2014-06-01

In the hope of making passenger travel times shorter and more reliable, many cities are introducing dedicated bus lanes (e.g., Bogota, London, Miami). Here we show that chaotic travel times are actually a natural consequence of individual bus function, and hence of public transport systems more generally, i.e., chaotic dynamics emerge even when the route is empty and straight, stops and lights are equidistant and regular, and loading times are negligible. More generally, our findings provide a novel example of chaotic dynamics emerging from a single object following Newton's laws of motion in a regularized one-dimensional system.

Road safety issues for bus transport management.

PubMed

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

2013-11-01

Because of the low percentage of crashes involving buses and the assumption that public transport improves road safety by reducing vehicular traffic, public interest in bus safety is not as great as that in the safety of other types of vehicles. It is possible that less attention is paid to the significance of crashes involving buses because the safety level of bus systems is considered to be adequate. The purpose of this study was to evaluate the knowledge and perceptions of bus managers with respect to safety issues and the potential effectiveness of various technologies in achieving higher safety standards. Bus managers were asked to give their opinions on safety issues related to drivers (training, skills, performance evaluation and behaviour), vehicles (maintenance and advanced devices) and roads (road and traffic safety issues) in response to a research survey. Kendall's algorithm was used to evaluate the level of concordance. The results showed that the majority of the proposed items were considered to have great potential for improving bus safety. The data indicated that in the experience of the participants, passenger unloading and pedestrians crossing near bus stops are the most dangerous actions with respect to vulnerable users. The final results of the investigation showed that start inhibition, automatic door opening, and the materials and internal architecture of buses were considered the items most strongly related to bus passenger safety. Brake assistance and vehicle monitoring systems were also considered to be very effective. With the exception of driver assistance systems for passenger and pedestrian safety, the perceptions of the importance of other driver assistance systems for vehicle monitoring and bus safety were not unanimous among the bus company managers who participated in this survey. The study results showed that the introduction of new technologies is perceived as an important factor in improving bus safety, but a better understanding of their actual effectiveness and related risk factor avoidance must be developed to permit their useful implementation in bus fleets. Copyright © 2013 Elsevier Ltd. All rights reserved.

Bus-stop shelters : improved safety (phases 1 and 2).

DOT National Transportation Integrated Search

2010-07-01

This research was undertaken to 1) design and construct a wall and basic subassembly of an emergency : storm shelter comprised entirely of wood that could resist a missile (15 lb [6.8 kg], 12-ft [3.66 m] long : 2x4 from FEMA 361 specifications)...

Automated Passenger Counting Systems : Synopsis of Working Group Meeting : Transportation Systems Center, March 23-25, 1982

DOT National Transportation Integrated Search

1983-05-01

The mechanics of automated passenger counting on transit buses and the accuracy of these systems are discussed. Count data needs to be time coded and distance/location information is necessary for effectively correlating data to specific bus stops or...

Minimizing the health and climate impacts of emissions from heavy-duty public transportation bus fleets through operational optimization.

PubMed

Gouge, Brian; Dowlatabadi, Hadi; Ries, Francis J

2013-04-16

In contrast to capital control strategies (i.e., investments in new technology), the potential of operational control strategies (e.g., vehicle scheduling optimization) to reduce the health and climate impacts of the emissions from public transportation bus fleets has not been widely considered. This case study demonstrates that heterogeneity in the emission levels of different bus technologies and the exposure potential of bus routes can be exploited though optimization (e.g., how vehicles are assigned to routes) to minimize these impacts as well as operating costs. The magnitude of the benefits of the optimization depend on the specific transit system and region. Health impacts were found to be particularly sensitive to different vehicle assignments and ranged from worst to best case assignment by more than a factor of 2, suggesting there is significant potential to reduce health impacts. Trade-offs between climate, health, and cost objectives were also found. Transit agencies that do not consider these objectives in an integrated framework and, for example, optimize for costs and/or climate impacts alone, risk inadvertently increasing health impacts by as much as 49%. Cost-benefit analysis was used to evaluate trade-offs between objectives, but large uncertainties make identifying an optimal solution challenging.

Optimal PMU placement using topology transformation method in power systems.

PubMed

Rahman, Nadia H A; Zobaa, Ahmed F

2016-09-01

Optimal phasor measurement units (PMUs) placement involves the process of minimizing the number of PMUs needed while ensuring the entire power system completely observable. A power system is identified observable when the voltages of all buses in the power system are known. This paper proposes selection rules for topology transformation method that involves a merging process of zero-injection bus with one of its neighbors. The result from the merging process is influenced by the selection of bus selected to merge with the zero-injection bus. The proposed method will determine the best candidate bus to merge with zero-injection bus according to the three rules created in order to determine the minimum number of PMUs required for full observability of the power system. In addition, this paper also considered the case of power flow measurements. The problem is formulated as integer linear programming (ILP). The simulation for the proposed method is tested by using MATLAB for different IEEE bus systems. The explanation of the proposed method is demonstrated by using IEEE 14-bus system. The results obtained in this paper proved the effectiveness of the proposed method since the number of PMUs obtained is comparable with other available techniques.

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

PubMed Central

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

2015-01-01

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

Spatial regression analysis of traffic crashes in Seoul.

PubMed

Rhee, Kyoung-Ah; Kim, Joon-Ki; Lee, Young-ihn; Ulfarsson, Gudmundur F

2016-06-01

Traffic crashes can be spatially correlated events and the analysis of the distribution of traffic crash frequency requires evaluation of parameters that reflect spatial properties and correlation. Typically this spatial aspect of crash data is not used in everyday practice by planning agencies and this contributes to a gap between research and practice. A database of traffic crashes in Seoul, Korea, in 2010 was developed at the traffic analysis zone (TAZ) level with a number of GIS developed spatial variables. Practical spatial models using available software were estimated. The spatial error model was determined to be better than the spatial lag model and an ordinary least squares baseline regression. A geographically weighted regression model provided useful insights about localization of effects. The results found that an increased length of roads with speed limit below 30 km/h and a higher ratio of residents below age of 15 were correlated with lower traffic crash frequency, while a higher ratio of residents who moved to the TAZ, more vehicle-kilometers traveled, and a greater number of access points with speed limit difference between side roads and mainline above 30 km/h all increased the number of traffic crashes. This suggests, for example, that better control or design for merging lower speed roads with higher speed roads is important. A key result is that the length of bus-only center lanes had the largest effect on increasing traffic crashes. This is important as bus-only center lanes with bus stop islands have been increasingly used to improve transit times. Hence the potential negative safety impacts of such systems need to be studied further and mitigated through improved design of pedestrian access to center bus stop islands. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

Performance comparison of genetic algorithms and particle swarm optimization for model integer programming bus timetabling problem

NASA Astrophysics Data System (ADS)

Wihartiko, F. D.; Wijayanti, H.; Virgantari, F.

2018-03-01

Genetic Algorithm (GA) is a common algorithm used to solve optimization problems with artificial intelligence approach. Similarly, the Particle Swarm Optimization (PSO) algorithm. Both algorithms have different advantages and disadvantages when applied to the case of optimization of the Model Integer Programming for Bus Timetabling Problem (MIPBTP), where in the case of MIPBTP will be found the optimal number of trips confronted with various constraints. The comparison results show that the PSO algorithm is superior in terms of complexity, accuracy, iteration and program simplicity in finding the optimal solution.

Alternative Fuels Data Center: Multi-Modal Transportation

Science.gov Websites

examples of resources to help travelers use multi-modal transportation. OpenTripPlanner Map - an online transportation modes including transit (bus or train), walking, and bicycling 511 - a one-stop source from the of alternative transportation modes. A 2010 evaluation by the Oregon Transportation Research and

Bus transit operational efficiency resulting from passenger boardings at park-and-ride facilities.

DOT National Transportation Integrated Search

2016-08-01

In order to save time and money by not driving to an ultimate destination, some urban commuters drive themselves a few miles to specially designated parking lots built for transit customers and located where trains or buses stop. The focus of this pa...

46 CFR 116.202 - Plans and information required.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Safety Center, 2100 2nd St. SW., Stop 7102, Washington, DC 20593-7102, in a written or electronic format... cables, bus-tie cables, feeders, and branch circuit cables; (vi) Power, lighting, and interior communication panelboards with number of circuits and rating of energy consuming devices; (vii) Type and...

46 CFR 116.202 - Plans and information required.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Safety Center, 2100 2nd St. SW., Stop 7102, Washington, DC 20593-7102, in a written or electronic format... cables, bus-tie cables, feeders, and branch circuit cables; (vi) Power, lighting, and interior communication panelboards with number of circuits and rating of energy consuming devices; (vii) Type and...

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.

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

From Bus Stop to Farm Village: The Farm Worker Programme in Zimbabwe.

ERIC Educational Resources Information Center

Auret, Diana

This book documents the history, successes, and failures of Save the Children's farmworker program in Zimbabwe, 1981-98. The report explores workers' past and present living and working conditions on commercial farms and describes how the program promoted a progression from workers with a migrant mentality to the building of functional…

Research on connection structure of aluminumbody bus using multi-objective topology optimization

NASA Astrophysics Data System (ADS)

Peng, Q.; Ni, X.; Han, F.; Rhaman, K.; Ulianov, C.; Fang, X.

2018-01-01

For connecting Aluminum Alloy bus body aluminum components often occur the problem of failure, a new aluminum alloy connection structure is designed based on multi-objective topology optimization method. Determining the shape of the outer contour of the connection structure with topography optimization, establishing a topology optimization model of connections based on SIMP density interpolation method, going on multi-objective topology optimization, and improving the design of the connecting piece according to the optimization results. The results show that the quality of the aluminum alloy connector after topology optimization is reduced by 18%, and the first six natural frequencies are improved and the strength performance and stiffness performance are obviously improved.

Aerial view of the newest bus stop to view Launch Pad 39B

NASA Technical Reports Server (NTRS)

1998-01-01

Tour buses unload passengers at a new stop on the KSC tour that allows visitors to view Pad LC-39B. The tour road runs parallel to the crawlerway (just out of sight) that is used to transport the Space Shuttle vehicles to the pad. The length of the crawlerway from the Vehicle Assembly Building to Pad B is 6,828 meters (22,440 ft); its width overall is 40 meters (130 ft); each lane is 12 meters (40ft) with a 15-meter (50ft) median. This view looks south.

Short-range evaluation of air pollution near bus and railway stations.

PubMed

Corfa, E; Maury, F; Segers, P; Fresneau, A; Albergel, A

2004-12-01

In the early morning, during workdays, intensive activity is observed at both bus and railway stations. This particular time is critical because of the combination of three factors: (1) simultaneous departure of many buses and trains, (2) cold engines, and, quite frequently, (3) stable meteorological conditions. In our approach, we use ARIA Local, a simulation package applying CFD tools to air pollution modeling, to study different scenarios. The CFD model used in this study is the MERCURE model, developed by Electricite de France. For a bus station, we simulate a typical morning peak hour situation and study in detail how the pollution is accumulated in the station courtyard and the impact on the close vicinity. Two scenarios are presented: one with classical diesel engine and one with buses using AQUAZOL or NGV fuel. The definition of the sources inside the Eulerian grid is described as static linear sources. The total emission is averaged over the mean path driven by the bus from the bus stop to the exit of the bus station. For a railway station, we simulate a situation in a real railway station within the city of Paris. The emission from a diesel "locomotive" and its impact on air quality is computed and compared to the impact of other nonmobile emissions. In this case, the definition of sources is described as mobile point sources following the trajectory of the train. These two scenarios are discussed in an urban context, taking into account the flow around buildings and different meteorological conditions.

Optimal Congestion Management in Electricity Market Using Particle Swarm Optimization with Time Varying Acceleration Coefficients

NASA Astrophysics Data System (ADS)

Boonyaritdachochai, Panida; Boonchuay, Chanwit; Ongsakul, Weerakorn

2010-06-01

This paper proposes an optimal power redispatching approach for congestion management in deregulated electricity market. Generator sensitivity is considered to indicate the redispatched generators. It can reduce the number of participating generators. The power adjustment cost and total redispatched power are minimized by particle swarm optimization with time varying acceleration coefficients (PSO-TVAC). The IEEE 30-bus and IEEE 118-bus systems are used to illustrate the proposed approach. Test results show that the proposed optimization scheme provides the lowest adjustment cost and redispatched power compared to the other schemes. The proposed approach is useful for the system operator to manage the transmission congestion.

Economic Load Dispatch Using Adaptive Social Acceleration Constant Based Particle Swarm Optimization

NASA Astrophysics Data System (ADS)

Jain, N. K.; Nangia, Uma; Jain, Jyoti

2018-04-01

In this paper, an Adaptive Social Acceleration Constant based Particle Swarm Optimization (ASACPSO) has been developed which uses the best value of social acceleration constant (Csg). Three formulations of Csg have been used to search for the best value of Csg. These three formulations led to the development of three algorithms-ALDPSO, AELDPSO-I and AELDPSO-II which were implemented for Economic Load Dispatch of IEEE 5 bus, 14 bus and 30 bus systems. The best value of Csg was selected based on the minimum number of Kounts i.e. number of function evaluations required to minimize the function. This value of Csg was directly used in basic PSO algorithm which led to the development of ASACPSO algorithm. ASACPSO was found to converge faster and give more accurate results compared to BPSO for IEEE 5, 14 and 30 bus systems.

Helping Black and Latino Males Succeed

ERIC Educational Resources Information Center

Jackson, Robert

2016-01-01

Growing up in a poor, dysfunctional family in a violent inner-city neighborhood, Jackson faced daily challenges even getting to the bus stop without being attacked by gang members. When he was bused to a white suburban school in 5th grade, things got even worse. Every black student who was bused in from his neighborhood was placed in remedial…

Best practices for using geographic data in transit : a location referencing guidebook : defining geographic locations of bus stops, routes and other map data for ITS, GIS and operational efficiencies

DOT National Transportation Integrated Search

2005-04-01

This Guidebook was developed at the request of the transit industry. It provides best practices for both transit managers and technical staff with respect to planning, implementing and using geographic data in transit. The Guidebook discusses issues ...

The Bus Stops Here: The Case for Biodiesel in School Buses.

ERIC Educational Resources Information Center

Rao, Steven T.

2002-01-01

Suggests that diesel exhaust from most of the nation's school buses may be hazardous to children's health. Documents studies on the nature and potential magnitude of the risk to children and proposes replacing petroleum diesel with biodiesel as the fuel for school buses. Presents the merits and practicality of switching to biodiesel as a healthier…

Genetic Algorithm for Multiple Bus Line Coordination on Urban Arterial

PubMed Central

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

2015-01-01

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

Indonesian commercial bus drum brake system temperature model

NASA Astrophysics Data System (ADS)

Wibowo, D. B.; Haryanto, I.; Laksono, N. P.

2016-03-01

Brake system is the most significant aspect of an automobile safety. It must be able to slow the vehicle, quickly intervening and reliable under varying conditions. Commercial bus in Indonesia, which often stops suddenly and has a high initial velocity, will raise the temperature of braking significantly. From the thermal analysis it is observed that for the bus with the vehicle laden mass of 15 tons and initial velocity of 80 km/h the temperature is increasing with time and reaches the highest temperature of 270.1 °C when stops on a flat road and reaches 311.2 °C on a declination road angle, ø, 20°. These temperatures exceeded evaporation temperature of brake oil DOT 3 and DOT 4. Besides that, the magnitude of the braking temperature also potentially lowers the friction coefficient of more than 30%. The brakes are pressed repeatedly and high-g decelerations also causes brake lining wear out quickly and must be replaced every 1 month as well as the emergence of a large thermal stress which can lead to thermal cracking or thermal fatigue crack. Brake fade phenomenon that could be the cause of many buses accident in Indonesia because of the failure of the braking function. The chances of accidents will be even greater when the brake is worn and not immediately replaced which could cause hot spots as rivets attached to the brake drum and brake oil is not changed for more than 2 years that could potentially lower the evaporation temperature because of the effect hygroscopic.

Development of a microscale land use regression model for predicting NO2 concentrations at a heavy trafficked suburban area in Auckland, NZ.

PubMed

Weissert, L F; Salmond, J A; Miskell, G; Alavi-Shoshtari, M; Williams, D E

2018-04-01

Land use regression (LUR) analysis has become a key method to explain air pollutant concentrations at unmeasured sites at city or country scales, but little is known about the applicability of LUR at microscales. We present a microscale LUR model developed for a heavy trafficked section of road in Auckland, New Zealand. We also test the within-city transferability of LUR models developed at different spatial scales (local scale and city scale). Nitrogen dioxide (NO 2 ) was measured during summer at 40 sites and a LUR model was developed based on standard criteria. The results showed that LUR models are able to capture the microscale variability with the model explaining 66% of the variability in NO 2 concentrations. Predictor variables identified at this scale were street width, distance to major road, presence of awnings and number of bus stops, with the latter three also being important determinants at the local scale. This highlights the importance of street and building configurations for individual exposure at the street level. However, within-city transferability was limited with the number of bus stops being the only significant predictor variable at all spatial scales and locations tested, indicating the strong influence of diesel emissions related to bus traffic. These findings show that air quality monitoring is necessary at a high spatial density within cities in capturing small-scale variability in NO 2 concentrations at the street level and assessing individual exposure to traffic related air pollutants. Copyright © 2017. Published by Elsevier B.V.

Indonesian commercial bus drum brake system temperature model

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

Wibowo, D. B., E-mail: rmt.bowo@gmail.com; Haryanto, I., E-mail: ismoyo2001@yahoo.de; Laksono, N. P., E-mail: priyolaksono89@gmail.com

Brake system is the most significant aspect of an automobile safety. It must be able to slow the vehicle, quickly intervening and reliable under varying conditions. Commercial bus in Indonesia, which often stops suddenly and has a high initial velocity, will raise the temperature of braking significantly. From the thermal analysis it is observed that for the bus with the vehicle laden mass of 15 tons and initial velocity of 80 km/h the temperature is increasing with time and reaches the highest temperature of 270.1 °C when stops on a flat road and reaches 311.2 °C on a declination road angle,more » ø, 20°. These temperatures exceeded evaporation temperature of brake oil DOT 3 and DOT 4. Besides that, the magnitude of the braking temperature also potentially lowers the friction coefficient of more than 30%. The brakes are pressed repeatedly and high-g decelerations also causes brake lining wear out quickly and must be replaced every 1 month as well as the emergence of a large thermal stress which can lead to thermal cracking or thermal fatigue crack. Brake fade phenomenon that could be the cause of many buses accident in Indonesia because of the failure of the braking function. The chances of accidents will be even greater when the brake is worn and not immediately replaced which could cause hot spots as rivets attached to the brake drum and brake oil is not changed for more than 2 years that could potentially lower the evaporation temperature because of the effect hygroscopic.« less

Study on transfer optimization of urban rail transit and conventional public transport

NASA Astrophysics Data System (ADS)

Wang, Jie; Sun, Quan Xin; Mao, Bao Hua

2018-04-01

This paper mainly studies the time optimization of feeder connection between rail transit and conventional bus in a shopping center. In order to achieve the goal of connecting rail transportation effectively and optimizing the convergence between the two transportations, the things had to be done are optimizing the departure intervals, shorting the passenger transfer time and improving the service level of public transit. Based on the goal that has the minimum of total waiting time of passengers and the number of start of classes, establish the optimizing model of bus connecting of departure time. This model has some constrains such as transfer time, load factor, and the convergence of public transportation grid spacing. It solves the problems by using genetic algorithms.

Socioeconomic differences in outdoor food advertising at public transit stops across Melbourne suburbs.

PubMed

Settle, Philippa J; Cameron, Adrian J; Thornton, Lukar E

2014-10-01

To assess and compare the number and type of outdoor food advertisements at public transit stops within suburbs of varying levels of socioeconomic disadvantage. An observational audit tool was developed and implemented to assess the number and type of food advertisements at public transit stops within Melbourne, Victoria. A total of 20 Melbourne neighbourhoods (suburbs) from across the least and the most socioeconomically disadvantaged areas were selected. All public transit stops, including train stations and bus and tram stops with a shelter were audited.  A similar proportion of transit stops in the least and most-disadvantaged suburbs displayed food advertisements (total n=203). However, some differences in the type of advertisements across suburbs were noted with advertisements for fast food restaurants, flavoured milk and fruit juice more common in the most-disadvantaged neighbourhoods (all p<0.05) and advertisements for diet soft drink, tea, coffee and convenience stores more common in the least-disadvantaged neighbourhoods (all p<0.05). This exploration of outdoor food advertising at Melbourne transit stops found 30% displayed food advertisements, with those in more disadvantaged suburbs more frequently promoting chain-brand fast food and less frequently promoting diet varieties of soft drinks. These findings may help raise awareness of unhealthy environmental exposures. © 2014 Public Health Association of Australia.

Quantification of Self Pollution from Two Diesel School Buses using Three Independent Methods.

PubMed

Liu, L-J Sally; Phuleria, Harish C; Webber, Whitney; Davey, Mark; Lawson, Douglas R; Ireson, Robert G; Zielinska, Barbara; Ondov, John M; Weaver, Christopher S; Lapin, Charles A; Easter, Michael; Hesterberg, Thomas W; Larson, Timothy

2010-09-01

We monitored two Seattle school buses to quantify the buses' self pollution using the dual tracers (DT), lead vehicle (LV), and chemical mass balance (CMB) methods. Each bus drove along a residential route simulating stops, with windows closed or open. Particulate matter (PM) and its constituents were monitored in the bus and from a LV. We collected source samples from the tailpipe and crankcase emissions using an on-board dilution tunnel. Concentrations of PM(1), ultrafine particle counts, elemental and organic carbon (EC/OC) were higher on the bus than the LV. The DT method estimated that the tailpipe and the crankcase emissions contributed 1.1 and 6.8 mug/m(3) of PM(2.5) inside the bus, respectively, with significantly higher crankcase self pollution (SP) when windows were closed. Approximately two-thirds of in-cabin PM(2.5) originated from background sources. Using the LV approach, SP estimates from the EC and the active personal DataRAM (pDR) measurements correlated well with the DT estimates for tailpipe and crankcase emissions, respectively, although both measurements need further calibration for accurate quantification. CMB results overestimated SP from the DT method but confirmed crankcase emissions as the major SP source. We confirmed buses' SP using three independent methods and quantified crankcase emissions as the dominant contributor.

Quantification of self pollution from two diesel school buses using three independent methods

NASA Astrophysics Data System (ADS)

Sally Liu, L.-J.; Phuleria, Harish C.; Webber, Whitney; Davey, Mark; Lawson, Douglas R.; Ireson, Robert G.; Zielinska, Barbara; Ondov, John M.; Weaver, Christopher S.; Lapin, Charles A.; Easter, Michael; Hesterberg, Thomas W.; Larson, Timothy

2010-09-01

We monitored two Seattle school buses to quantify the buses' self pollution using the dual tracers (DT), lead vehicle (LV), and chemical mass balance (CMB) methods. Each bus drove along a residential route simulating stops, with windows closed or open. Particulate matter (PM) and its constituents were monitored in the bus and from a LV. We collected source samples from the tailpipe and crankcase emissions using an on-board dilution tunnel. Concentrations of PM 1, ultrafine particle counts, elemental and organic carbon (EC/OC) were higher on the bus than the LV. The DT method estimated that the tailpipe and the crankcase emissions contributed 1.1 and 6.8 μg m -3 of PM 2.5 inside the bus, respectively, with significantly higher crankcase self pollution (SP) when windows were closed. Approximately two-thirds of in-cabin PM 2.5 originated from background sources. Using the LV approach, SP estimates from the EC and the active personal DataRAM (pDR) measurements correlated well with the DT estimates for tailpipe and crankcase emissions, respectively, although both measurements need further calibration for accurate quantification. CMB results overestimated SP from the DT method but confirmed crankcase emissions as the major SP source. We confirmed buses' SP using three independent methods and quantified crankcase emissions as the dominant contributor.

A Feeder-Bus Dispatch Planning Model for Emergency Evacuation in Urban Rail Transit Corridors

PubMed Central

Wang, Yun; Yan, Xuedong; Zhou, Yu; Zhang, Wenyi

2016-01-01

The mobility of modern metropolises strongly relies on urban rail transit (URT) systems, and such a heavy dependence causes that even minor service interruptions would make the URT systems unsustainable. This study aims at optimally dispatching the ground feeder-bus to coordinate with the urban rails’ operation for eliminating the effect of unexpected service interruptions in URT corridors. A feeder-bus dispatch planning model was proposed for the collaborative optimization of URT and feeder-bus cooperation under emergency situations and minimizing the total evacuation cost of the feeder-buses. To solve the model, a concept of dummy feeder-bus system is proposed to transform the non-linear model into traditional linear programming (ILP) model, i.e., traditional transportation problem. The case study of Line #2 of Nanjing URT in China was adopted to illustrate the model application and sensitivity analyses of the key variables. The modeling results show that as the evacuation time window increases, the total evacuation cost as well as the number of dispatched feeder-buses decrease, and the dispatched feeder-buses need operate for more times along the feeder-bus line. The number of dispatched feeder-buses does not show an obvious change with the increase of parking spot capacity and time window, indicating that simply increasing the parking spot capacity would cause huge waste for the emergent bus utilization. When the unbalanced evacuation demand exists between stations, the more feeder-buses are needed. The method of this study will contribute to improving transportation emergency management and resource allocation for URT systems. PMID:27676179

Biomechanical and ergonomic assessment of urban transit operators.

PubMed

Albert, Wayne J; Everson, Donald; Rae, Michelle; Callaghan, Jack P; Croll, Jim; Kuruganti, Usha

2014-01-01

The prevalence of neck and low back musculoskeletal injuries in transit operators has been shown to be high; with work absences exceeding double the National average. There is a lack of biomechanical data generated from field researches to inform on musculoskeletal risk associated with transportation and driving occupations. Instead there has been a reliance on simulated driving and questionnaire-based research. This study was designed to examine the musculoskeletal and biomechanical stresses experienced by urban bus drivers. The main objective was to obtain a baseline understanding of sitting posture, muscle activiation and subjective ratings of stress during regular driving tasks. Fifteen urban city bus drivers were recruited for this study. Bus drivers drove the same 65-minute bus route once, at the same time of day, in the same preselected bus. Wireless surface electromyography monitored muscular activity of the drivers' neck, upper trapezius, and erector spinae and video analysis and seat pressure mapping was used to monitor changes in driving posture. A health and lifestyle questionnaire was administered to record specific neck and back pain experienced by drivers as well as to provide lifestyle habits. Drivers were found to exhibit non-neutral postures for less than 30% of the time while conducting routine tasks of turning and stopping for passenger loading and unloading. The neck posture was the greatest concern in terms of non-neutral posture and this was supported by the higher muscle activation to the neck musculature. There was significant posture adjustment made during the one-hour driving period with the adjustments increasing with driving time. Activities associated with bus driving appear to require the use of non-neutral postures an increase in muscle activation. Significant postural adjustments were needed over the one-hour observation period suggesting that the musculoskeletal demands may increase over a regular 12-hour shift.

Distance to retail stores and risk of being homebound among older adults in a city severely affected by the 2011 Great East Japan Earthquake

PubMed Central

Hirai, Hiroshi; Kondo, Naoki; Sasaki, Ryohei; Iwamuro, Shinya; Masuno, Kanako; Ohtsuka, Rika; Miura, Hisayuki; Sakata, Kiyomi

2015-01-01

Background: after the Great East Japan Earthquake in 2011, inactivity and the homebound status of older victims in affected areas have been a serious public health concern owing to the victims' prolonged existence as evacuees in mountainous areas. Objective: to evaluate the association between distances to retail stores and risks of being homebound. Design: secondary analysis of cross-sectional interview survey data with a geographical information analysis. Setting: Rikuzentakata, Iwate, a municipality seriously damaged by the 2011 earthquake and tsunami. Subjects: all Rikuzentakata residents aged 65 or older except for those living in temporary housing (n = 2,327). Methods: we calculated road distances between each residential address and retail stores, hawker sites and shopping bus stops, accounting for the extra load caused by walking on slopes. The prevalence ratio of being homebound adjusted for age, source of income and morbidity by road distance was estimated using Poisson regression with a generalised estimating equation. Results: those living at distances of 1,200 m or more were 1.78 (95% confidence intervals, 1.03–3.08) times more likely to be homebound (going out only every 4 or more days a week) among men and 1.85 (1.13-3.02) among women, compared with those residing in places <400 m from retail stores or shopping bus stops. The distances were reduced by new hawker and shopping bus services, but the improvements varied greatly across the districts. Conclusions: access to daily needs is essential to prevent homebound status. Post-disaster community diagnosis in terms of the built environment is important for strategic community restoration. PMID:25315229

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

Synchronous clock stopper for microprocessor

NASA Technical Reports Server (NTRS)

Kitchin, David A. (Inventor)

1985-01-01

A synchronous clock stopper circuit for inhibiting clock pulses to a microprocessor in response to a stop request signal, and for reinstating the clock pulses in response to a start request signal thereby to conserve power consumption of the microprocessor when used in an environment of limited power. The stopping and starting of the microprocessor is synchronized, by a phase tracker, with the occurrences of a predetermined phase in the instruction cycle of the microprocessor in which the I/O data and address lines of the microprocessor are of high impedance so that a shared memory connected to the I/O lines may be accessed by other peripheral devices. The starting and stopping occur when the microprocessor initiates and completes, respectively, an instruction, as well as before and after transferring data with a memory. Also, the phase tracker transmits phase information signals over a bus to other peripheral devices which signals identify the current operational phase of the microprocessor.

Metal Whiskers: A Discussion of Risks and Mitigation

DTIC Science & Technology

2010-11-30

efforts to investigate – Chromate conversion finishes DO NOT appear to stop whisker formation [4] S. Arnold, "Repressing the Growth of Tin Whiskers...November 30, 2010 Metal Whiskers 10 Examples of Metal Whiskers Zinc-Plated Steel Bus Rail with Yellow Chromate Conversion Finish Zinc whiskers grew...Metal Whiskers 11 Examples of Metal Whiskers Tin-Plated D-Sub Connector Shell Connector Advertised as “RoHS Compliant” November 30, 2010 Metal

DG Planning with Amalgamation of Operational and Reliability Considerations

NASA Astrophysics Data System (ADS)

Battu, Neelakanteshwar Rao; Abhyankar, A. R.; Senroy, Nilanjan

2016-04-01

Distributed Generation has been playing a vital role in dealing issues related to distribution systems. This paper presents an approach which provides policy maker with a set of solutions for DG placement to optimize reliability and real power loss of the system. Optimal location of a Distributed Generator is evaluated based on performance indices derived for reliability index and real power loss. The proposed approach is applied on a 15-bus radial distribution system and a 18-bus radial distribution system with conventional and wind distributed generators individually.

Speed limiter integrated fatigue analyzer (SLIFA) for speed and fatigue control on diesel engine truck and bus

NASA Astrophysics Data System (ADS)

Wahyudi, Haris; Pranoto, Hadi; Leman, A. M.; Sebayang, Darwin; Baba, I.

2017-09-01

Every second, the number of road traffic deaths is increased globally with millions more sustaining severe injuries and living with long-term adverse health consequences. Jakarta alone in year 2015 had recorded 556 people died due to road accidents, approximately reached 6.231 road accident cases. The identified major contributory factors of such unfortunate events are both driver fatigue and over speeding habit especially related to the driving of truck and bus. This paper presents the idea on how to control the electronic system from input fuel system of injection pump and the combustion chamber engine will control the valve solenoid in injection pump which can lock and fuel will stop for moment, and speed limit can be success, by using sensor heart rate we can input reduce speed limit when fatigue detection driver. Integration process this tool can be relevant when Speed Limiter Integrated Fatigue Analyser (SLIFA) trial in the diesel engine for truck and bus, the result of this research Speed Limiter Integrated Fatigue Analyser (SLIFA) able to control speed of diesel engine for truck and bus almost 30km/h, 60km/h, and until 70 km/h. The installation of the sensor heart rate as the input speed limit SLIFA would work when the driver is detected to be in the fatigue condition. We make Speed Limiter Integrated Fatigue Analyser (SLIFA) for control and monitoring system for diesel engine in truck and bus. Speed Limiter Integrated Fatigue Analyser (SLIFA) system can save the historical of the speed record, fatigue, rpm, and body temperature of the driver.

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.

Quantification of Self Pollution from Two Diesel School Buses using Three Independent Methods

PubMed Central

Liu, L.-J. Sally; Phuleria, Harish C.; Webber, Whitney; Davey, Mark; Lawson, Douglas R.; Ireson, Robert G.; Zielinska, Barbara; Ondov, John M.; Weaver, Christopher S.; Lapin, Charles A.; Easter, Michael; Hesterberg, Thomas W.; Larson, Timothy

2010-01-01

We monitored two Seattle school buses to quantify the buses’ self pollution using the dual tracers (DT), lead vehicle (LV), and chemical mass balance (CMB) methods. Each bus drove along a residential route simulating stops, with windows closed or open. Particulate matter (PM) and its constituents were monitored in the bus and from a LV. We collected source samples from the tailpipe and crankcase emissions using an on-board dilution tunnel. Concentrations of PM1, ultrafine particle counts, elemental and organic carbon (EC/OC) were higher on the bus than the LV. The DT method estimated that the tailpipe and the crankcase emissions contributed 1.1 and 6.8 μg/m3 of PM2.5 inside the bus, respectively, with significantly higher crankcase self pollution (SP) when windows were closed. Approximately two-thirds of in-cabin PM2.5 originated from background sources. Using the LV approach, SP estimates from the EC and the active personal DataRAM (pDR) measurements correlated well with the DT estimates for tailpipe and crankcase emissions, respectively, although both measurements need further calibration for accurate quantification. CMB results overestimated SP from the DT method but confirmed crankcase emissions as the major SP source. We confirmed buses’ SP using three independent methods and quantified crankcase emissions as the dominant contributor. PMID:20694046

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.

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.

TLBO based Voltage Stable Environment Friendly Economic Dispatch Considering Real and Reactive Power Constraints

NASA Astrophysics Data System (ADS)

Verma, H. K.; Mafidar, P.

2013-09-01

In view of growing concern towards environment, power system engineers are forced to generate quality green energy. Hence the economic dispatch (ED) aims at the power generation to meet the load demand at minimum fuel cost with environmental and voltage constraints along with essential constraints on real and reactive power. The emission control which reduces the negative impact on environment is achieved by including the additional constraints in ED problem. Presently, the power system mostly operates near its stability limits, therefore with increased demand the system faces voltage problem. The bus voltages are brought within limit in the present work by placement of static var compensator (SVC) at weak bus which is identified from bus participation factor. The optimal size of SVC is determined by univariate search method. This paper presents the use of Teaching Learning based Optimization (TLBO) algorithm for voltage stable environment friendly ED problem with real and reactive power constraints. The computational effectiveness of TLBO is established through test results over particle swarm optimization (PSO) and Big Bang-Big Crunch (BB-BC) algorithms for the ED problem.

Energy efficient motion control of the electric bus on route

NASA Astrophysics Data System (ADS)

Kotiev, G. O.; Butarovich, D. O.; Kositsyn, B. B.

2018-02-01

At present, the urgent problem is the reduction of energy costs of urban motor transport. The article proposes a method of solving this problem by developing an energy-efficient law governing the movement of an electric bus along a city route. To solve this problem, an algorithm is developed based on the dynamic programming method. The proposed method allows you to take into account the constraints imposed on the phase coordinates, control action, as well as on the time of the route. In the course of solving the problem, the model of rectilinear motion of an electric bus on a horizontal reference surface is considered, taking into account the assumptions that allow it to be adapted for the implementation of the method. For the formation of a control action in the equations of motion dynamics, an algorithm for changing the traction / braking torque on the wheels of an electric bus is considered, depending on the magnitude of the control parameter and the speed of motion. An optimal phase trajectory was obtained on a selected section of the road for the prototype of an electric bus. The article presents the comparison of simulation results obtained with the optimal energy efficient control law with the results obtained by a test driver. The comparison proved feasibility of the energy efficient control law for the automobile city electric transport.

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.

Economic Optimization Analysis of Chengdu Electric Community Bus Operation

NASA Astrophysics Data System (ADS)

Yidong, Wang; Yun, Cai; Zhengping, Tan; Xiong, Wan

2018-03-01

In recent years, the government has strongly supported and promoted electric vehicles and has given priority to demonstration and popularization in the field of public transport. The economy of public transport operations has drawn increasing attention. In this paper, Chengdu wireless charging pure electric community bus is used as the research object, the battery, air conditioning, driver’s driving behavior and other economic influence factors were analyzed, and optimizing the operation plan through case data analysis, through the reasonable battery matching and mode of operation to help businesses effectively save operating costs and enhance economic efficiency.

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.

Writing on the Bus: Using Athletic Team Notebooks and Journals to Advance Learning and Performance in Sports

ERIC Educational Resources Information Center

Kent, Richard

2012-01-01

"Writing on the Bus" showcases the what, how, and why of using athletic team notebooks and journals. The book guides coaches and athletes, from elementary school through college, in analyzing games while thinking deeply about motivation, goal setting, and communication in order to optimize performance. Filled with lesson plans, writing activities,…

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.

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.

Fuzzy control based engine sizing optimization for a fuel cell/battery hybrid mini-bus

NASA Astrophysics Data System (ADS)

Kim, Minjin; Sohn, Young-Jun; Lee, Won-Yong; Kim, Chang-Soo

The fuel cell/battery hybrid vehicle has been focused for the alternative engine of the existing internal-combustion engine due to the following advantages of the fuel cell and the battery. Firstly, the fuel cell is highly efficient and eco-friendly. Secondly, the battery has the fast response for the changeable power demand. However, the competitive efficiency of the hybrid fuel cell vehicle is necessary to successfully alternate the conventional vehicles with the fuel cell hybrid vehicle. The most relevant factor which affects the overall efficiency of the hybrid fuel cell vehicle is the relative engine sizing between the fuel cell and the battery. Therefore the design method to optimize the engine sizing of the fuel cell hybrid vehicle has been proposed. The target system is the fuel cell/battery hybrid mini-bus and its power distribution is controlled based on the fuzzy logic. The optimal engine sizes are determined based on the simulator developed in this paper. The simulator includes the several models for the fuel cell, the battery, and the major balance of plants. After the engine sizing, the system efficiency and the stability of the power distribution are verified based on the well-known driving schedule. Consequently, the optimally designed mini-bus shows good performance.

Inseparability of Go and Stop in Inhibitory Control: Go Stimulus Discriminability Affects Stopping Behavior.

PubMed

Ma, Ning; Yu, Angela J

2016-01-01

Inhibitory control, the ability to stop or modify preplanned actions under changing task conditions, is an important component of cognitive functions. Two lines of models of inhibitory control have previously been proposed for human response in the classical stop-signal task, in which subjects must inhibit a default go response upon presentation of an infrequent stop signal: (1) the race model, which posits two independent go and stop processes that race to determine the behavioral outcome, go or stop; and (2) an optimal decision-making model, which posits that observers decides whether and when to go based on continually (Bayesian) updated information about both the go and stop stimuli. In this work, we probe the relationship between go and stop processing by explicitly manipulating the discrimination difficulty of the go stimulus. While the race model assumes the go and stop processes are independent, and therefore go stimulus discriminability should not affect the stop stimulus processing, we simulate the optimal model to show that it predicts harder go discrimination should result in longer go reaction time (RT), lower stop error rate, as well as faster stop-signal RT. We then present novel behavioral data that validate these model predictions. The results thus favor a fundamentally inseparable account of go and stop processing, in a manner consistent with the optimal model, and contradicting the independence assumption of the race model. More broadly, our findings contribute to the growing evidence that the computations underlying inhibitory control are systematically modulated by cognitive influences in a Bayes-optimal manner, thus opening new avenues for interpreting neural responses underlying inhibitory control.

Images of Eyes Enhance Investments in a Real-Life Public Good

PubMed Central

Francey, Damien; Bergmüller, Ralph

2012-01-01

A key issue in cooperation research is to determine the conditions under which individuals invest in a public good. Here, we tested whether cues of being watched increase investments in an anonymous public good situation in real life. We examined whether individuals would invest more by removing experimentally placed garbage (paper and plastic bottles) from bus stop benches in Geneva in the presence of images of eyes compared to controls (images of flowers). We provided separate bins for each of both types of garbage to investigate whether individuals would deposit more items into the appropriate bin in the presence of eyes. The treatment had no effect on the likelihood that individuals present at the bus stop would remove garbage. However, those individuals that engaged in garbage clearing, and were thus likely affected by the treatment, invested more time to do so in the presence of eyes. Images of eyes had a direct effect on behaviour, rather than merely enhancing attention towards a symbolic sign requesting removal of garbage. These findings show that simple images of eyes can trigger reputational effects that significantly enhance on non-monetary investments in anonymous public goods under real life conditions. We discuss our results in the light of previous findings and suggest that human social behaviour may often be shaped by relatively simple and potentially unconscious mechanisms instead of very complex cognitive capacities. PMID:22624026

Predictive optimized adaptive PSS in a single machine infinite bus.

PubMed

Milla, Freddy; Duarte-Mermoud, Manuel A

2016-07-01

Power System Stabilizer (PSS) devices are responsible for providing a damping torque component to generators for reducing fluctuations in the system caused by small perturbations. A Predictive Optimized Adaptive PSS (POA-PSS) to improve the oscillations in a Single Machine Infinite Bus (SMIB) power system is discussed in this paper. POA-PSS provides the optimal design parameters for the classic PSS using an optimization predictive algorithm, which adapts to changes in the inputs of the system. This approach is part of small signal stability analysis, which uses equations in an incremental form around an operating point. Simulation studies on the SMIB power system illustrate that the proposed POA-PSS approach has better performance than the classical PSS. In addition, the effort in the control action of the POA-PSS is much less than that of other approaches considered for comparison. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Novel optimization technique of isolated microgrid with hydrogen energy storage.

PubMed

Beshr, Eman Hassan; Abdelghany, Hazem; Eteiba, Mahmoud

2018-01-01

This paper presents a novel optimization technique for energy management studies of an isolated microgrid. The system is supplied by various Distributed Energy Resources (DERs), Diesel Generator (DG), a Wind Turbine Generator (WTG), Photovoltaic (PV) arrays and supported by fuel cell/electrolyzer Hydrogen storage system for short term storage. Multi-objective optimization is used through non-dominated sorting genetic algorithm to suit the load requirements under the given constraints. A novel multi-objective flower pollination algorithm is utilized to check the results. The Pros and cons of the two optimization techniques are compared and evaluated. An isolated microgrid is modelled using MATLAB software package, dispatch of active/reactive power, optimal load flow analysis with slack bus selection are carried out to be able to minimize fuel cost and line losses under realistic constraints. The performance of the system is studied and analyzed during both summer and winter conditions and three case studies are presented for each condition. The modified IEEE 15 bus system is used to validate the proposed algorithm.

Novel optimization technique of isolated microgrid with hydrogen energy storage

PubMed Central

Abdelghany, Hazem; Eteiba, Mahmoud

2018-01-01

This paper presents a novel optimization technique for energy management studies of an isolated microgrid. The system is supplied by various Distributed Energy Resources (DERs), Diesel Generator (DG), a Wind Turbine Generator (WTG), Photovoltaic (PV) arrays and supported by fuel cell/electrolyzer Hydrogen storage system for short term storage. Multi-objective optimization is used through non-dominated sorting genetic algorithm to suit the load requirements under the given constraints. A novel multi-objective flower pollination algorithm is utilized to check the results. The Pros and cons of the two optimization techniques are compared and evaluated. An isolated microgrid is modelled using MATLAB software package, dispatch of active/reactive power, optimal load flow analysis with slack bus selection are carried out to be able to minimize fuel cost and line losses under realistic constraints. The performance of the system is studied and analyzed during both summer and winter conditions and three case studies are presented for each condition. The modified IEEE 15 bus system is used to validate the proposed algorithm. PMID:29466433

Power-balancing instantaneous optimization energy management for a novel series-parallel hybrid electric bus

NASA Astrophysics Data System (ADS)

Sun, Dongye; Lin, Xinyou; Qin, Datong; Deng, Tao

2012-11-01

Energy management(EM) is a core technique of hybrid electric bus(HEB) in order to advance fuel economy performance optimization and is unique for the corresponding configuration. There are existing algorithms of control strategy seldom take battery power management into account with international combustion engine power management. In this paper, a type of power-balancing instantaneous optimization(PBIO) energy management control strategy is proposed for a novel series-parallel hybrid electric bus. According to the characteristic of the novel series-parallel architecture, the switching boundary condition between series and parallel mode as well as the control rules of the power-balancing strategy are developed. The equivalent fuel model of battery is implemented and combined with the fuel of engine to constitute the objective function which is to minimize the fuel consumption at each sampled time and to coordinate the power distribution in real-time between the engine and battery. To validate the proposed strategy effective and reasonable, a forward model is built based on Matlab/Simulink for the simulation and the dSPACE autobox is applied to act as a controller for hardware in-the-loop integrated with bench test. Both the results of simulation and hardware-in-the-loop demonstrate that the proposed strategy not only enable to sustain the battery SOC within its operational range and keep the engine operation point locating the peak efficiency region, but also the fuel economy of series-parallel hybrid electric bus(SPHEB) dramatically advanced up to 30.73% via comparing with the prototype bus and a similar improvement for PBIO strategy relative to rule-based strategy, the reduction of fuel consumption is up to 12.38%. The proposed research ensures the algorithm of PBIO is real-time applicability, improves the efficiency of SPHEB system, as well as suite to complicated configuration perfectly.

Bring Me Men: Intertextual Identity Formation at the US Air Force Academy

DTIC Science & Technology

2008-09-01

equivalent performance from the alienated gender was a surprise rather than an expectation; the "Women in the Air Force" display is a two panel glass...note card I held at eyelevel in front of me trying to memorize. The bus stopped before I could memorize all the information about General Butler , Class...the Wing is performed only twice in a cadet’s career; once after successful completion of Basic Cadet Training when the new Fourth Classmen

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.

Switching coordination of distributed dc-dc converters for highly efficient photovoltaic power plants

DOEpatents

Agamy, Mohammed; Elasser, Ahmed; Sabate, Juan Antonio; Galbraith, Anthony William; Harfman Todorovic, Maja

2014-09-09

A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

MightySat II.1 Hyperspectral Imager: Summary of On-Orbit Performance

DTIC Science & Technology

2002-01-01

are on board MightySat II.1, consisting of Experimental Bus Components and Stand-Alone Experiments . There are five Experimental Bus Components from...optimized for measuring vegetation in the visible to near infrared (600 to 900 nm) for terrain categorization purposes. Table 1 shows the design and...integration accounts for $6 million of the total cost. The adaptability of the satellite is seen in the amount and variety of experiments . Ten experiments

An implementation of particle swarm optimization to evaluate optimal under-voltage load shedding in competitive electricity markets

NASA Astrophysics Data System (ADS)

Hosseini-Bioki, M. M.; Rashidinejad, M.; Abdollahi, A.

2013-11-01

Load shedding is a crucial issue in power systems especially under restructured electricity environment. Market-driven load shedding in reregulated power systems associated with security as well as reliability is investigated in this paper. A technoeconomic multi-objective function is introduced to reveal an optimal load shedding scheme considering maximum social welfare. The proposed optimization problem includes maximum GENCOs and loads' profits as well as maximum loadability limit under normal and contingency conditions. Particle swarm optimization (PSO) as a heuristic optimization technique, is utilized to find an optimal load shedding scheme. In a market-driven structure, generators offer their bidding blocks while the dispatchable loads will bid their price-responsive demands. An independent system operator (ISO) derives a market clearing price (MCP) while rescheduling the amount of generating power in both pre-contingency and post-contingency conditions. The proposed methodology is developed on a 3-bus system and then is applied to a modified IEEE 30-bus test system. The obtained results show the effectiveness of the proposed methodology in implementing the optimal load shedding satisfying social welfare by maintaining voltage stability margin (VSM) through technoeconomic analyses.

Spatial distribution of diesel transit bus emissions and urban populations: implications of coincidence and scale on exposure.

PubMed

Gouge, Brian; Ries, Francis J; Dowlatabadi, Hadi

2010-09-15

Macroscale emissions modeling approaches have been widely applied in impact assessments of mobile source emissions. However, these approaches poorly characterize the spatial distribution of emissions and have been shown to underestimate emissions of some pollutants. To quantify the implications of these limitations on exposure assessments, CO, NO(X), and HC emissions from diesel transit buses were estimated at 50 m intervals along a bus rapid transit route using a microscale emissions modeling approach. The impacted population around the route was estimated using census, pedestrian count and transit ridership data. Emissions exhibited significant spatial variability. In intervals near major intersections and bus stops, emissions were 1.6-3.0 times higher than average. The coincidence of these emission hot spots and peaks in pedestrian populations resulted in a 20-40% increase in exposure compared to estimates that assumed homogeneous spatial distributions of emissions and/or populations along the route. An additional 19-30% increase in exposure resulted from the underestimate of CO and NO(X) emissions by macroscale modeling approaches. The results of this study indicate that macroscale modeling approaches underestimate exposure due to poor characterization of the influence of vehicle activity on the spatial distribution of emissions and total emissions.

Optimally Stopped Optimization

NASA Astrophysics Data System (ADS)

Vinci, Walter; Lidar, Daniel

We combine the fields of heuristic optimization and optimal stopping. We propose a strategy for benchmarking randomized optimization algorithms that minimizes the expected total cost for obtaining a good solution with an optimal number of calls to the solver. To do so, rather than letting the objective function alone define a cost to be minimized, we introduce a further cost-per-call of the algorithm. We show that this problem can be formulated using optimal stopping theory. The expected cost is a flexible figure of merit for benchmarking probabilistic solvers that can be computed when the optimal solution is not known, and that avoids the biases and arbitrariness that affect other measures. The optimal stopping formulation of benchmarking directly leads to a real-time, optimal-utilization strategy for probabilistic optimizers with practical impact. We apply our formulation to benchmark the performance of a D-Wave 2X quantum annealer and the HFS solver, a specialized classical heuristic algorithm designed for low tree-width graphs. On a set of frustrated-loop instances with planted solutions defined on up to N = 1098 variables, the D-Wave device is between one to two orders of magnitude faster than the HFS solver.

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

Delay correction model for estimating bus emissions at signalized intersections based on vehicle specific power distributions.

PubMed

Song, Guohua; Zhou, Xixi; Yu, Lei

2015-05-01

The intersection is one of the biggest emission points for buses and also the high exposure site for people. Several traffic performance indexes have been developed and widely used for intersection evaluations. However, few studies have focused on the relationship between these indexes and emissions at intersections. This paper intends to propose a model that relates emissions to the two commonly used measures of effectiveness (i.e. delay time and number of stops) by using bus activity data and emission data at intersections. First, with a large number of field instantaneous emission data and corresponding activity data collected by the Portable Emission Measurement System (PEMS), emission rates are derived for different vehicle specific power (VSP) bins. Then, 2002 sets of trajectory data, an equivalent of about 140,000 sets of second-by-second activity data, are obtained from Global Position Systems (GPSs)-equipped diesel buses in Beijing. The delay and the emission factors of each trajectory are estimated. Then, by using baseline emission factors for two types of intersections, e.g. the Arterial @ Arterial Intersection and the Arterial @ Collector, delay correction factors are calculated for the two types of intersections at different congestion levels. Finally, delay correction models are established for adjusting emission factors for each type of intersections and different numbers of stops. A comparative analysis between estimated and field emission factors demonstrates that the delay correction model is reliable. Copyright © 2015 Elsevier B.V. All rights reserved.

[Consent to smoking in public places and at home the opinions of smokers and nonsmokers girls].

PubMed

Kowalewska, Anna

2010-01-01

The aim of this study was researching of dependence between current status of smoking and opinions about smoking tobacco in public places and at home of girls at the age 18. We examined 2246 girls who graduated junior high schools and were continuing their education in four types of schools: high schools, profiled high schools, technical secondary schools and vocational schools. Two-stage sampling method was used, with the team stratification by type of school. The study was conducted in November and December 2008, the auditorium method. The results show that although more than half of the girls, do not agree with smoking in various public places and by parents at home, about one quarter of them accept smoking in cafes, restaurants, pubs and bus stops, and less than 1/5 have no opinion on the subject. Applied analysis using logistic regression analysis indicate a close relationship between smoking trials undertaken by the girls examined, and their opinion about the approval for smoking by students at the school. The model attempts to smoking was a significant predictor of acceptance of smoking in cafes and pubs, and the model of the current consensus on tobacco smoking at bus stops. The presented results indicate the need for prevention activities among children and adolescents, which will contribute to the education of attitudes and skills necessary to take measures aimed at creating environments free from tobacco smoke.

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.

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.

Combined comfort model of thermal comfort and air quality on buses in Hong Kong.

PubMed

Shek, Ka Wing; Chan, Wai Tin

2008-01-25

Air-conditioning settings are important factors in controlling the comfort of passengers on buses. The local bus operators control in-bus air quality and thermal environment by conforming to the prescribed levels stated in published standards. As a result, the settings are merely adjusted to fulfill the standards, rather than to satisfy the passengers' thermal comfort and air quality. Such "standard-oriented" practices are not appropriate; the passengers' preferences and satisfaction should be emphasized instead. Thus a "comfort-oriented" philosophy should be implemented to achieve a comfortable in-bus commuting environment. In this study, the achievement of a comfortable in-bus environment was examined with emphasis on thermal comfort and air quality. Both the measurement of physical parameters and subjective questionnaire surveys were conducted to collect practical in-bus thermal and air parameters data, as well as subjective satisfaction and sensation votes from the passengers. By analyzing the correlation between the objective and subjective data, a combined comfort models were developed. The models helped in evaluating the percentage of dissatisfaction under various combinations of passengers' sensation votes towards thermal comfort and air quality. An effective approach integrated the combined comfort model, hardware and software systems and the bus air-conditioning system could effectively control the transient in-bus environment. By processing and analyzing the data from the continuous monitoring system with the combined comfort model, air-conditioning setting adjustment commands could be determined and delivered to the hardware. This system adjusted air-conditioning settings depending on real-time commands along the bus journey. Therefore, a comfortable in-bus air quality and thermal environment could be achieved and efficiently maintained along the bus journey despite dynamic outdoor influences. Moreover, this model can help optimize air-conditioning control by striking a beneficial balance between energy conservation and passengers' satisfaction level.

On Per-Phase Topology Control and Switching in Emerging Distribution Systems

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

Ding, Fei; Mousavi, Mirrasoul J.

This paper presents a new concept and approach for topology control and switching in distribution systems by extending the traditional circuit switching to laterals and single-phase loads. Voltage unbalance and other key performance indicators including voltage magnitudes, line loading, and energy losses are used to characterize and demonstrate the technical value of optimizing system topology on a per-phase basis in response to feeder conditions. The near-optimal per-phase topology control is defined as a series of hierarchical optimization problems. The proposed approach is respectively applied to IEEE 13-bus and 123-bus test systems for demonstration, which included the impact of integrating electricmore » vehicles (EVs) in the test circuit. It is concluded that the proposed approach can be effectively leveraged to improve voltage profiles with electric vehicles, the extent of which depends upon the performance of the base case without EVs.« less

A study investigating the travel habits and preferences of older Australian adults with a falls risk.

PubMed

McCluskey, Annie; Thurtell, Andrew; Clemson, Lindy; Kendig, Hal

2011-12-01

  To investigate the travel habits and preferences of city-dwelling older Australians with a falls risk, and factors influencing outings.   A retrospective cross-sectional survey was conducted with 96 community-dwelling adults with a falls risk.   The mean age of participants was 78.2 years (SD 5.33). The majority were women (77%). Most (75%) went on five or more outings per week (mean 6.9 outings). Men drove more than women (41% vs 31%). Shopping was the most common reason for outings. Walking was the most frequent mode of travel, and buses were both the easiest and most difficult. Factors that enabled bus travel included bus stop location, good services and cheap fares. Primary reasons for restricting outings were poor health, transport barriers, neighbourhood safety and personal motivation.   These older adults went out nearly every day. Findings can be used to improve transport services for older people. © 2010 The Authors. Australasian Journal on Ageing © 2010 ACOTA.

Correlates of walking to school and implications for public policies: survey results from parents of elementary school children in Austin, Texas.

PubMed

Zhu, Xuemei; Lee, Chanam

2009-01-01

Walking can be a healthy, sustainable, and equitable mode of transportation, but is not widely used for children's school travel. This study identifies multi-level correlates of walking to/from school and relevant policy implications. We surveyed parents/guardians of 2,695 students from 19 elementary schools in Austin, Texas, which featured diverse sociodemographic and environmental characteristics. Among the personal and social factors, negative correlates were parents' education, car ownership, personal barriers, and school bus availability; positive correlates were parents' and children's positive attitude and regular walking behavior, and supportive peer influences. Of physical environmental factors, the strongest negative correlates were distance and safety concerns, followed by the presence of highways/freeways, convenience stores, office buildings, and bus stops en route. Our findings suggest that society should give high priority to lower socioeconomic status populations and to multi-agency policy interventions that facilitate environmental changes, safety improvements, and educational programs targeting both parents and children.

Position reporting system using small satellites

NASA Technical Reports Server (NTRS)

Pavesi, B.; Rondinelli, G.; Graziani, F.

1990-01-01

A system able to provide position reporting and monitoring services for mobile applications represents a natural complement to the Global Positioning System (GPS) navigation system. The system architecture is defined on the basis of the communications requirements derived by user needs, allowing maximum flexibility in the use of channel capacity, and a very simple and low cost terminal. The payload is sketched, outlining the block modularity and the use of qualified hardware. The global system capacity is also derived. The spacecraft characteristics are defined on the basis of the payload requirements. A small bus optimized for Ariane IV, Delta II vehicles and based on the modularity concept is presented. The design takes full advantage of each launcher with a common basic bus or bus elements for a mass production.

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.

Improved estimation of commuter waiting times using headway and commuter boarding information

NASA Astrophysics Data System (ADS)

Ramli, Muhamad Azfar; Jayaraman, Vasundhara; Kwek, Hyen Chee; Tan, Kian Heong; Lee Kee Khoon, Gary; Monterola, Christopher

2018-07-01

The average amount of waiting time spent by commuters is one of the key indicators of service quality for public bus operations. While actual measurements of actual waiting time is difficult to be done en masse, models of waiting time can be derived from bus headways and these models have been adopted by transport planners in monitoring and regulating service reliability of operators. However, these models are founded on several assumptions on the patterns of commuter arrival which may not be applicable for bus services that experience high demand and heavily fluctuating commuter patterns. Given the availability of granular data on commuter boarding from automated fare collection systems, we propose a new methodology to better estimate the average waiting time of commuters. The formulation is anchored and validated using a three-month dataset from ten selected bus routes in Singapore. Finally, we discuss how our new measure allows for minimization of commuter waiting time through schedule optimization.

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.

Replacement model of city bus: A dynamic programming approach

NASA Astrophysics Data System (ADS)

Arifin, Dadang; Yusuf, Edhi

2017-06-01

This paper aims to develop a replacement model of city bus vehicles operated in Bandung City. This study is driven from real cases encountered by the Damri Company in the efforts to improve services to the public. The replacement model propounds two policy alternatives: First, to maintain or keep the vehicles, and second is to replace them with new ones taking into account operating costs, revenue, salvage value, and acquisition cost of a new vehicle. A deterministic dynamic programming approach is used to solve the model. The optimization process was heuristically executed using empirical data of Perum Damri. The output of the model is to determine the replacement schedule and the best policy if the vehicle has passed the economic life. Based on the results, the technical life of the bus is approximately 20 years old, while the economic life is an average of 9 (nine) years. It means that after the bus is operated for 9 (nine) years, managers should consider the policy of rejuvenation.

Comparison of on-road emissions for hybrid and regular transit buses.

PubMed

Hallmark, Shauna L; Wang, Bo; Sperry, Robert

2013-10-01

Hybrid technology offers an attractive option for transit buses, since it has the potential to significantly reduce operating costs for transit agencies. The main impetus behind use of hybrid transit vehicles is fuel savings and reduced emissions. Laboratory tests have indicated that hybrid transit buses can have significantly lower emissions compared with conventional transit buses. However the number of studies is limited and laboratory tests may not represent actual driving conditions, since in-use vehicle operation differs from laboratory test cycles. This paper describes an on-road evaluation of in-use emission differences between hybrid-electric and conventional transit buses for the Ames, Iowa transit authority, CyRide. Emissions were collected on-road using a portable emissions monitoring system (PEMS) for three hybrid and two control buses. Emissions were collected for at least one operating bus day. Each bus was evaluated over the same route pattern, which utilizes the same driver. The number of passengers embarking or disembarking at each stop was collected by an on-board data collector so that passenger load could be included. Vehicle emissions are correlated to engine load demand, which is a function of factors such as vehicle load, speed, and acceleration. PEMS data are provided second by second and vehicle-specific power (VSP) was calculated for each row of data. Instantaneous data were stratified into the defined VSP bins and then average modal emission rates and standard errors were calculated for each bus for each pollutant. Pollutants were then compared by bus type. Carbon dioxide, carbon monoxide, and hydrocarbon emissions were higher for the regular buses across most VSP bins than for the hybrid buses. Nitrogen oxide emissions were unexpectedly higher for the hybrid buses than for the control buses.

Bus operators' responses to job strain: An experimental test of the job demand-control model.

PubMed

Cendales-Ayala, Boris; Useche, Sergio Alejandro; Gómez-Ortiz, Viviola; Bocarejo, Juan Pablo

2017-10-01

The research aim was to test the Job Demand-Control (JDC) Model demands × Control interaction (or buffering) hypothesis in a simulated bus driving experiment. The buffering hypothesis was tested using a 2 (low and high demands) × 2 (low and high decision latitude) design with repeated measures on the second factor. A sample of 80 bus operators were randomly assigned to the low (n = 40) and high demands (n = 40) conditions. Demands were manipulated by increasing or reducing the number of stops to pick up passengers, and decision latitude by imposing or removing restrictions on the Rapid Transit Bus (BRT) operators' pace of work. Outcome variables include physiological markers (heart rate [HR], heart rate variability [HRV], breathing rate [BR], electromyography [EMG], and skin conductance [SC]), objective driving performance and self-report measurements of psychological wellbeing (psychological distress, interest/enjoyment [I/E], perceived competence, effort/importance [E/I], and pressure/tension [P/T]). It was found that job decision latitude moderates the effect of job demands on both physiological arousal (BR: F(1, 74) = 4.680, p = .034, SC: F(1, 75) = 6.769, p = .011, and EMG: F(1, 75) = 6.550, p = .013) and psychological well-being (P/T: F(1, 75) = 4.289, p = .042 and I/E: F(1, 74) = 4.548, p = .036). Consistently with the JDC model buffering hypothesis, the experimental findings suggest that increasing job decision latitude can moderate the negative effect of job demands on different psychophysiological outcomes. This finding is useful for designing organizational and clinical interventions in an occupational group at high risk of work stress-related disease. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Economic Benefit of Introducing a Bus Rapid Transit (BRT) in Kano State Nigeria

NASA Astrophysics Data System (ADS)

Ahmad, K. A.; Afolabi, S.; Nda, M.; Daura, H. A.

2018-04-01

The objective of this study is to know the variables use in quantifying economic benefits of public transport project, contribution of public transport to economic productivity This paper attempts to provide a Road User Cost (RUC) comparison of current usage of Buses and Cars in three different stages which are the present time, do nothing and the introduction of new modes. Vehicle operating cost (VOC), value of time (VOT), pollution cost, accident cost and environmental cost are calculated in other to know the benefits for their abilities to ensure accessibility and mobility, reduce accidents and reduce environmental loss. The study stretch involves an 11.1 km of 2-lane divided carriageway road connecting Kabuga bus stop to Janguza market. Social costs which included accident costs, accident cost of cars (private modes) were found to be 50 times the accident cost of bus accidents. California Air Resource Board (CARB) model was adopted to evaluate Environmental costs. The total road user costs were then obtained to provide comparative evaluation among the study modes. Furthermore, the multiple future scenarios were created to provide understanding about the need for inclusion of other modes. In this regard, this paper provided a framework for the cost evaluation for an urban area and results indicate that buses are more cost-effective in transportation of equivalent number of passengers.

Cycle Tracks and Parking Environments in China: Learning from College Students at Peking University

PubMed Central

Yuan, Changzheng; Sun, Yangbo; Lv, Jun; Lusk, Anne C.

2017-01-01

China has a historic system of wide cycle tracks, many of which are now encroached by cars, buses and bus stops. Even with these conditions, college students still bicycle. On campuses, students park their bikes on facilities ranging from kick-stand-plazas to caged sheds with racks, pumps and an attendant. In other countries, including Canada, some of the newer cycle tracks need to be wider to accommodate an increasing number of bicyclists. Other countries will also need to improve their bike parking, which includes garage-basement cages and two-tiered racks. China could provide lessons about cycle tracks and bike parking. This study applied the Maslow Transportation Level of Service (LOS) theory, i.e., for cycle tracks and bike parking, only after the basic needs of safety and security are met for both vehicle occupants and bicyclists can the higher needs of convenience and comfort be met. With random clustering, a self-administered questionnaire was collected from 410 students in six dormitory buildings at Peking University in Beijing and an environmental scan of bicycle parking conducted in school/office and living areas. Cycle tracks (1 = very safe/5 = very unsafe) shared with moving cars were most unsafe (mean = 4.6), followed by sharing with parked cars (4.1) or bus stop users (4.1) (p < 0.001). Close to half thought campus bike parking lacked order. The most suggested parking facilities were sheds, security (guard or camera), bicycle racks and bicycle parking services (pumps, etc.). If parking were improved, three quarters indicated they would bicycle more. While caged sheds were preferred, in living areas with 1597 parked bikes, caged sheds were only 74.4% occupied. For the future of China’s wide cycle tracks, perhaps a fence-separated bus lane beside a cycle track might be considered or, with China’s recent increase in bike riding, shared bikes and E-bikes, perhaps cars/buses could be banned from the wide cycle tracks. In other countries, a widened cycle track entrance should deter cars. Everywhere, bike parking sheds could be built and redesigned with painted lines to offer more space and order, similar to car parking. PMID:28820463

Cycle Tracks and Parking Environments in China: Learning from College Students at Peking University.

PubMed

Yuan, Changzheng; Sun, Yangbo; Lv, Jun; Lusk, Anne C

2017-08-18

China has a historic system of wide cycle tracks, many of which are now encroached by cars, buses and bus stops. Even with these conditions, college students still bicycle. On campuses, students park their bikes on facilities ranging from kick-stand-plazas to caged sheds with racks, pumps and an attendant. In other countries, including Canada, some of the newer cycle tracks need to be wider to accommodate an increasing number of bicyclists. Other countries will also need to improve their bike parking, which includes garage-basement cages and two-tiered racks. China could provide lessons about cycle tracks and bike parking. This study applied the Maslow Transportation Level of Service (LOS) theory, i.e., for cycle tracks and bike parking, only after the basic needs of safety and security are met for both vehicle occupants and bicyclists can the higher needs of convenience and comfort be met. With random clustering, a self-administered questionnaire was collected from 410 students in six dormitory buildings at Peking University in Beijing and an environmental scan of bicycle parking conducted in school/office and living areas. Cycle tracks (1 = very safe/5 = very unsafe) shared with moving cars were most unsafe (mean = 4.6), followed by sharing with parked cars (4.1) or bus stop users (4.1) ( p < 0.001). Close to half thought campus bike parking lacked order. The most suggested parking facilities were sheds, security (guard or camera), bicycle racks and bicycle parking services (pumps, etc.). If parking were improved, three quarters indicated they would bicycle more. While caged sheds were preferred, in living areas with 1597 parked bikes, caged sheds were only 74.4% occupied. For the future of China's wide cycle tracks, perhaps a fence-separated bus lane beside a cycle track might be considered or, with China's recent increase in bike riding, shared bikes and E-bikes, perhaps cars/buses could be banned from the wide cycle tracks. In other countries, a widened cycle track entrance should deter cars. Everywhere, bike parking sheds could be built and redesigned with painted lines to offer more space and order, similar to car parking.

Optimally Stopped Optimization

NASA Astrophysics Data System (ADS)

Vinci, Walter; Lidar, Daniel A.

2016-11-01

We combine the fields of heuristic optimization and optimal stopping. We propose a strategy for benchmarking randomized optimization algorithms that minimizes the expected total cost for obtaining a good solution with an optimal number of calls to the solver. To do so, rather than letting the objective function alone define a cost to be minimized, we introduce a further cost-per-call of the algorithm. We show that this problem can be formulated using optimal stopping theory. The expected cost is a flexible figure of merit for benchmarking probabilistic solvers that can be computed when the optimal solution is not known and that avoids the biases and arbitrariness that affect other measures. The optimal stopping formulation of benchmarking directly leads to a real-time optimal-utilization strategy for probabilistic optimizers with practical impact. We apply our formulation to benchmark simulated annealing on a class of maximum-2-satisfiability (MAX2SAT) problems. We also compare the performance of a D-Wave 2X quantum annealer to the Hamze-Freitas-Selby (HFS) solver, a specialized classical heuristic algorithm designed for low-tree-width graphs. On a set of frustrated-loop instances with planted solutions defined on up to N =1098 variables, the D-Wave device is 2 orders of magnitude faster than the HFS solver, and, modulo known caveats related to suboptimal annealing times, exhibits identical scaling with problem size.

Heterogeneity Index for the Assessment of Relationship Between Land Use Pattern and Road Traffic Congestion in Apapa-Oworoshoki Express way, Lagos Metropolis

NASA Astrophysics Data System (ADS)

Alaigba, D. B.; Soumah, M.; Banjo, M. O.

2017-05-01

The problem of urban mobility is complicated by traffic delay, resulting from poor planning, high population density and poor condition of roads within urban spaces. This study assessed traffic congestion resulting from differential contribution made by various land-uses along Apapa-Oworoshoki expressway in Lagos metropolis. The data for this study was from both primary and secondary sources; GPS point data was collected at selected points for traffic volume count; observation of the nature of vehicular traffic congestion, and land use types along the corridor. Existing data on traffic count along the corridor, connectivity map and land use map sourced from relevant authorities were acquired. Traffic congestion within the area was estimated using volume capacity ratio (V/C). Heterogeneity Index was developed and used to quantify the percentage contribution to traffic volume from various land-use categories. Analytical Hierarchical Processing (AHP) and knowledge-based weighting were used to rank the importance of different heterogeneity indices. Results showed significant relationship between the degree of heterogeneity of the land use pattern and road traffic congestion. Volume Capacity Ratio computed revealed that the route corridor exceeds its designed capacity in the southward direction between the hours of 8am and 12pm on working days. Five major nodes were analyzed along the corridor, and were all above the expected Passenger Car Unit (PCU), these are "Oshodi" 15 %, "Airport junction" 10 %, "Cele bus stop" 21 %, "Mile 2" 14 %, "Berger" 15 % and "Tincan bus stop" 33 % indicating heavy traffic congestion.

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.

Spacecraft configuration study for second generation mobile satellite system

NASA Technical Reports Server (NTRS)

Louie, M.; Vonstentzsch, W.; Zanella, F.; Hayes, R.; Mcgovern, F.; Tyner, R.

1985-01-01

A high power, high performance communicatons satellite bus being developed is designed to satisfy a broad range of multimission payload requirements in a cost effective manner and is compatible with both STS and expendable launchers. Results are presented of tradeoff studies conducted to optimize the second generation mobile satellite system for its mass, power, and physical size. Investigations of the 20-meter antenna configuration, transponder linearization techniques, needed spacecraft modifications, and spacecraft power, dissipation, mass, and physical size indicate that the advanced spacecraft bus is capable of supporting the required payload for the satellite.

Optimal subinterval selection approach for power system transient stability simulation

DOE PAGES

Kim, Soobae; Overbye, Thomas J.

2015-10-21

Power system transient stability analysis requires an appropriate integration time step to avoid numerical instability as well as to reduce computational demands. For fast system dynamics, which vary more rapidly than what the time step covers, a fraction of the time step, called a subinterval, is used. However, the optimal value of this subinterval is not easily determined because the analysis of the system dynamics might be required. This selection is usually made from engineering experiences, and perhaps trial and error. This paper proposes an optimal subinterval selection approach for power system transient stability analysis, which is based on modalmore » analysis using a single machine infinite bus (SMIB) system. Fast system dynamics are identified with the modal analysis and the SMIB system is used focusing on fast local modes. An appropriate subinterval time step from the proposed approach can reduce computational burden and achieve accurate simulation responses as well. As a result, the performance of the proposed method is demonstrated with the GSO 37-bus system.« less

Developing a discrete event simulation model for university student shuttle buses

NASA Astrophysics Data System (ADS)

Zulkepli, Jafri; Khalid, Ruzelan; Nawawi, Mohd Kamal Mohd; Hamid, Muhammad Hafizan

2017-11-01

Providing shuttle buses for university students to attend their classes is crucial, especially when their number is large and the distances between their classes and residential halls are far. These factors, in addition to the non-optimal current bus services, typically require the students to wait longer which eventually opens a space for them to complain. To considerably reduce the waiting time, providing the optimal number of buses to transport them from location to location and the effective route schedules to fulfil the students' demand at relevant time ranges are thus important. The optimal bus number and schedules are to be determined and tested using a flexible decision platform. This paper thus models the current services of student shuttle buses in a university using a Discrete Event Simulation approach. The model can flexibly simulate whatever changes configured to the current system and report its effects to the performance measures. How the model was conceptualized and formulated for future system configurations are the main interest of this paper.

Fuel cells, batteries and super-capacitors stand-alone power systems management using optimal/flatness based-control

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

Benaouadj, M.; Aboubou, A.; Bahri, M.

2016-07-25

In this work, an optimal control (under constraints) based on the Pontryagin’s maximum principle is used to optimally manage energy flows in a basic PEM (Proton Exchange Membrane) fuel cells system associated to lithium-ion batteries and supercapacitors through a common DC bus having a voltage to stabilize using the differential flatness approach. The adaptation of voltage levels between different sources and load is ensured by use of three DC-DC converters, one boost connected to the PEM fuel cells, while the two others are buck/boost and connected to the lithiumion batteries and supercapacitors. The aim of this paper is to developmore » an energy management strategy that is able to satisfy the following objectives: Impose the power requested by a habitat (representing the load) according to a proposed daily consumption profile, Keep fuel cells working at optimal power delivery conditions, Maintain constant voltage across the common DC bus, Stabilize the batteries voltage and stored quantity of charge at desired values given by the optimal control. Results obtained under MATLAB/Simulink environment prove that the cited objectives are satisfied, validating then, effectiveness and complementarity between the optimal and flatness concepts proposed for energy management. Note that this study is currently in experimentally validation within MSE Laboratory.« less

Contraction Options and Optimal Multiple-Stopping in Spectrally Negative Lévy Models

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

Yamazaki, Kazutoshi, E-mail: kyamazak@kansai-u.ac.jp

This paper studies the optimal multiple-stopping problem arising in the context of the timing option to withdraw from a project in stages. The profits are driven by a general spectrally negative Lévy process. This allows the model to incorporate sudden declines of the project values, generalizing greatly the classical geometric Brownian motion model. We solve the one-stage case as well as the extension to the multiple-stage case. The optimal stopping times are of threshold-type and the value function admits an expression in terms of the scale function. A series of numerical experiments are conducted to verify the optimality and tomore » evaluate the efficiency of the algorithm.« less

Using real time traveler demand data to optimize commuter rail feeder systems.

DOT National Transportation Integrated Search

2012-08-01

"This report focuses on real time optimization of the Commuter Rail Circulator Route Network Design Problem (CRCNDP). The route configuration of the circulator system where to stop and the route among the stops is determined on a real-time ba...

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.

Grid-Optimization Program for Photovoltaic Cells

NASA Technical Reports Server (NTRS)

Daniel, R. E.; Lee, T. S.

1986-01-01

CELLOPT program developed to assist in designing grid pattern of current-conducting material on photovoltaic cell. Analyzes parasitic resistance losses and shadow loss associated with metallized grid pattern on both round and rectangular solar cells. Though performs sensitivity studies, used primarily to optimize grid design in terms of bus bar and grid lines by minimizing power loss. CELLOPT written in APL.

Variable Swing Optimal Parallel Links - Minimal Power, Maximal Density for Parallel Links

DTIC Science & Technology

2009-01-01

implemented; it allows controlling the transmitter current by a simple design of a differential pair with a 100 ohms termination resistor. Figure 3.4...optimization. Zuber, P., et al. 2005. 0-7695-2288-2. 21. A 36Gb/s ACCI Multi-Channel Bus using a Fully Differential Pulse Receiver. Wilson, Lei Luo

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.

Optimized MPPT algorithm for boost converters taking into account the environmental variables

NASA Astrophysics Data System (ADS)

Petit, Pierre; Sawicki, Jean-Paul; Saint-Eve, Frédéric; Maufay, Fabrice; Aillerie, Michel

2016-07-01

This paper presents a study on the specific behavior of the Boost DC-DC converters generally used for powering conversion of PV panels connected to a HVDC (High Voltage Direct Current) Bus. It follows some works pointing out that converter MPPT (Maximum Power Point Tracker) is severely perturbed by output voltage variations due to physical dependency of parameters as the input voltage, the output voltage and the duty cycle of the PWM switching control of the MPPT. As a direct consequence many converters connected together on a same load perturb each other because of the output voltage variations induced by fluctuations on the HVDC bus essentially due to a not insignificant bus impedance. In this paper we show that it is possible to include an internal computed variable in charge to compensate local and external variations to take into account the environment variables.

Optimal bus temperature for thermal comfort during a cool day.

PubMed

Velt, K B; Daanen, H A M

2017-07-01

A challenge for electric buses is to minimize heating and cooling power to maximally extend the driving range, but still provide sufficient thermal comfort for the driver and passengers. Therefore, we investigated the thermal sensation (TS) and thermal comfort (TC) of passengers in buses during a cool day (temperature 13.4 ± 0.5 °C, relative humidity (RH) 60 ± 5.8%) typical for the Dutch temperate maritime climate. 28 Males and 72 females rated TS and TC and gave information on age, stature, body weight and worn garments. The temperature in the bus of 22.5 ± 1.1 °C and RH of 59.9 ± 5.8% corresponded to a slightly warm feeling (TS = 0.85 ± 1.06) and TC of 0.39 ± 0.65. TS related significantly to bus temperature, clothing insulation and age. Linear regression based on these parameters showed that the temperature in the bus corresponding to TC = 0 and TS = 0 would have been 20.9 ± 0.6 °C. In conclusion, a 1.6 °C lower bus temperature during the investigated cool day probably would have led to less thermal discomfort and energy savings of electrical busses. The methodology to relate climatic measurements to subjective assessments is currently employed in a wider climatic range and may prove to be useful to find a better balance between thermal comfort and energy savings of the bus. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mathematical modeling for optimizing skip-stop rail transit operation strategy using genetic algorithm.

DOT National Transportation Integrated Search

2012-03-01

"With skip-stop rail transit operation, transit agencies can reduce their operating costs and fleet size, : and passengers can experience reduced in-transit travel times without extra track and technological : improvement. However, since skip-stop op...

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.

Time of flight system on a chip

NASA Technical Reports Server (NTRS)

Paschalidis, Nicholas P. (Inventor)

2006-01-01

A CMOS time-of-flight TOF system-on-a-chip SoC for precise time interval measurement with low power consumption and high counting rate has been developed. The analog and digital TOF chip may include two Constant Fraction Discriminators CFDs and a Time-to-Digital Converter TDC. The CFDs can interface to start and stop anodes through two preamplifiers and perform signal processing for time walk compensation (110). The TDC digitizes the time difference with reference to an off-chip precise external clock (114). One TOF output is an 11-bit digital word and a valid event trigger output indicating a valid event on the 11-bit output bus (116).

Multi-Objective Differential Evolution for Voltage Security Constrained Optimal Power Flow in Deregulated Power Systems

NASA Astrophysics Data System (ADS)

Roselyn, J. Preetha; Devaraj, D.; Dash, Subhransu Sekhar

2013-11-01

Voltage stability is an important issue in the planning and operation of deregulated power systems. The voltage stability problems is a most challenging one for the system operators in deregulated power systems because of the intense use of transmission line capabilities and poor regulation in market environment. This article addresses the congestion management problem avoiding offline transmission capacity limits related to voltage stability by considering Voltage Security Constrained Optimal Power Flow (VSCOPF) problem in deregulated environment. This article presents the application of Multi Objective Differential Evolution (MODE) algorithm to solve the VSCOPF problem in new competitive power systems. The maximum of L-index of the load buses is taken as the indicator of voltage stability and is incorporated in the Optimal Power Flow (OPF) problem. The proposed method in hybrid power market which also gives solutions to voltage stability problems by considering the generation rescheduling cost and load shedding cost which relieves the congestion problem in deregulated environment. The buses for load shedding are selected based on the minimum eigen value of Jacobian with respect to the load shed. In the proposed approach, real power settings of generators in base case and contingency cases, generator bus voltage magnitudes, real and reactive power demands of selected load buses using sensitivity analysis are taken as the control variables and are represented as the combination of floating point numbers and integers. DE/randSF/1/bin strategy scheme of differential evolution with self-tuned parameter which employs binomial crossover and difference vector based mutation is used for the VSCOPF problem. A fuzzy based mechanism is employed to get the best compromise solution from the pareto front to aid the decision maker. The proposed VSCOPF planning model is implemented on IEEE 30-bus system, IEEE 57 bus practical system and IEEE 118 bus system. The pareto optimal front obtained from MODE is compared with reference pareto front and the best compromise solution for all the cases are obtained from fuzzy decision making strategy. The performance measures of proposed MODE in two test systems are calculated using suitable performance metrices. The simulation results show that the proposed approach provides considerable improvement in the congestion management by generation rescheduling and load shedding while enhancing the voltage stability in deregulated power system.

An innovative solution to raise public awareness using a mobile colorectal clinic - The 'bowel bus'.

PubMed

Naguib, N; Lewis, M; Iredale, R; Pugh, R; Haray, P N

2017-03-01

Colorectal cancer is the fourth most common cancer in the United Kingdom; however, figures show that the uptake for bowel cancer screening lags behind other cancer screening programmes. This is a report of a multi-staged development of an outreach colorectal clinical community service provided through a Mobile Unit (a Bowel Bus). The unit delivers a one-stop colorectal clinic that provides a rapid access pathway to members of the public who have concerns about, or symptoms of, bowel cancer. The aims of the project were to increase public awareness about colorectal cancer and to provide an outreach clinic as a supplement to the hospital based colorectal clinic. This service is a result of collaborative efforts between Tenovus Cancer Care (TCC) and the colorectal surgery department of the local NHS Hospital. During one year, the Bowel Bus has provided services to 772 members of the local community. 244 patients were examined by the colorectal nurse specialist including 66 drop-in patients and 135 patients referred by the GPs. The service led to decrease in the waiting list for routine referrals to be seen in the colorectal clinic at the hospital from a mean of 10.5 weeks-5.9 weeks. A feedback questionnaire from 180 patients, used to audit the quality of the service, has confirmed an overwhelming satisfaction with the service. The Mobile Unit is a novel solution to addressing the ever increasing demand for specialist outpatient services without compromising the quality of care whilst enhancing the patient experience. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Subsystem design in aircraft power distribution systems using optimization

NASA Astrophysics Data System (ADS)

Chandrasekaran, Sriram

2000-10-01

The research reported in this dissertation focuses on the development of optimization tools for the design of subsystems in a modern aircraft power distribution system. The baseline power distribution system is built around a 270V DC bus. One of the distinguishing features of this power distribution system is the presence of regenerative power from the electrically driven flight control actuators and structurally integrated smart actuators back to the DC bus. The key electrical components of the power distribution system are bidirectional switching power converters, which convert, control and condition electrical power between the sources and the loads. The dissertation is divided into three parts. Part I deals with the formulation of an optimization problem for a sample system consisting of a regulated DC-DC buck converter preceded by an input filter. The individual subsystems are optimized first followed by the integrated optimization of the sample system. It is shown that the integrated optimization provides better results than that obtained by integrating the individually optimized systems. Part II presents a detailed study of piezoelectric actuators. This study includes modeling, optimization of the drive amplifier and the development of a current control law for piezoelectric actuators coupled to a simple mechanical structure. Linear and nonlinear methods to study subsystem interaction and stability are studied in Part III. A multivariable impedance ratio criterion applicable to three phase systems is proposed. Bifurcation methods are used to obtain global stability characteristics of interconnected systems. The application of a nonlinear design methodology, widely used in power systems, to incrementally improve the robustness of a system to Hopf bifurcation instability is discussed.

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.

Where to locate transit stops: Cross-intersection profiles of ultrafine particles and implications for pedestrian exposure.

PubMed

Choi, Wonsik; Ranasinghe, Dilhara; DeShazo, J R; Kim, Jae-Jin; Paulson, Suzanne E

2018-02-01

Epidemiological studies have shown that exposure to traffic-related pollutants increases incidence of adverse health outcomes. Transit users in cities across the globe commonly spend 15-45 min or more waiting at transit stops each day, often at locations with high levels of pollution from traffic. Here, we investigate the characteristics of concentration profiles of ultrafine particles (UFP) with 5 m spatial resolution across intersections, to determine the best place to site transit stops to minimize exposures. Cross-intersection UFP profiles were derived from 1744 profiles covering 90 m before and after each intersection center with a mobile monitoring platform. Measurements were made at 10 signalized intersections located at six urban sites, each with a distinct built environment, during both mornings and afternoons. Measurements were made within 1.5 m of the sidewalk and approximately at breathing height (1.5 m above ground level) to approximate sidewalk exposures. UFP profiles were strongly influenced by high emissions from vehicle stops and accelerations, and peaked within 30 m of intersection centers; from there concentrations decreased sharply with distance. Peak concentrations averaged about 90% higher than the minima along the block. They were accompanied by more frequent and larger transient concentration spikes, increasing the chance of people near the intersection being exposed to both short-term extremely high concentration spikes and higher average concentrations. The decays are somewhat larger before the intersection than after the intersection, however as siting transit stops after intersections is preferred for smooth traffic flow, we focus on after the intersection. Simple time-duration exposure calculations combined with breathing rates suggest moving a bus stop from 20 to 40-50 m after the intersection can reduce transit-users' exposure levels to total UFP substantially, in proportion to the reciprocal of the magnitude of elevation at the intersection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Finite Optimal Stopping Problems: The Seller's Perspective

ERIC Educational Resources Information Center

Hemmati, Mehdi; Smith, J. Cole

2011-01-01

We consider a version of an optimal stopping problem, in which a customer is presented with a finite set of items, one by one. The customer is aware of the number of items in the finite set and the minimum and maximum possible value of each item, and must purchase exactly one item. When an item is presented to the customer, she or he observes its…

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

Modified Shuffled Frog Leaping Optimization Algorithm Based Distributed Generation Rescheduling for Loss Minimization

NASA Astrophysics Data System (ADS)

Arya, L. D.; Koshti, Atul

2018-05-01

This paper investigates the Distributed Generation (DG) capacity optimization at location based on the incremental voltage sensitivity criteria for sub-transmission network. The Modified Shuffled Frog Leaping optimization Algorithm (MSFLA) has been used to optimize the DG capacity. Induction generator model of DG (wind based generating units) has been considered for study. Standard test system IEEE-30 bus has been considered for the above study. The obtained results are also validated by shuffled frog leaping algorithm and modified version of bare bones particle swarm optimization (BBExp). The performance of MSFLA has been found more efficient than the other two algorithms for real power loss minimization problem.

Power converters for the 120 V bus supply control

NASA Astrophysics Data System (ADS)

Elisabelar, Christian

1993-03-01

Power converters for the 120 V bus supply control in such projects as Columbus and Hermes are addressed. Because of the power levels involved and the existing state of the art, several converter modules need to be connected in parallel to supply a single bus. To simplify the study, the power of each converter is set at around 1 kW. Many converter structures which satisfy requirement specifications and several solutions, with or without galvanic insulation, are proposed. The choice and sizing of the converter structure are considered. Stress factors and available technology are selection criteria in determining the most suitable structures. The dimensions of each structure, taking into account the rules of space design enable efficiency to be analytically estimated and it is subsequently verified experimentally. The converter command and its functional performance are then addressed. Numerical simulations with SUCCESS software are run to observe the actual operation of the power part of the converter and to develop the command law with its regulation parameters. The converter is simulated in its entirety and different transients are studied like load variation, no load operating point, short circuit. The response time, stability and behavior under disturbed conditions are thus known. A comparison of the various structures studied enabled the optimal converter to be chosen for some 120 V regulated bus applications.

Study on the factors affecting the quality of public bus transportation service in Bali Province using factor analysis

NASA Astrophysics Data System (ADS)

Susilawati, M.; Nilakusmawati, D. P. E.

2017-06-01

The volume of mobility flows are increasing day by day and the condition of the number of people using private transport modes contribute to traffic congestion. With the limited capacity of the road, one of the alternatives solution to reduce congestion is to optimize the use of public transport. The purposes of this study are to determine the factors that influence user’s satisfaction on the quality of public bus transportation service and determine variables that became identifier on the dominant factor affecting user’s satisfaction. The study was conducted for the public bus transportation between districts in the province of Bali, which is among the eight regencies and one municipality, using a questionnaire as a data collection instrument. Service variables determinant of user’s satisfaction in this study, described in 25 questions, which were analyzed using factor analysis. The results showed there were six factors that explain the satisfaction of users of public transport in Bali, with a total diversity of data that can be parsed by 61.436%. These factors are: Safety and comfort, Responsiveness, Capacity, Tangible, Safety, Reliability. The dominant factor affecting public transport user satisfaction is the safety and comfort, with the most influential variable is feeling concerned about the personal safety of users when on the bus.

Method of recording bioelectrical signals using a capacitive coupling

NASA Astrophysics Data System (ADS)

Simon, V. A.; Gerasimov, V. A.; Kostrin, D. K.; Selivanov, L. M.; Uhov, A. A.

2017-11-01

In this article a technique for the bioelectrical signals acquisition by means of the capacitive sensors is described. A feedback loop for the ultra-high impedance biasing of the input instrumentation amplifier, which provides receiving of the electrical cardiac signal (ECS) through a capacitive coupling, is proposed. The mains 50/60 Hz noise is suppressed by a narrow-band stop filter with an independent notch frequency and quality factor tuning. Filter output is attached to a ΣΔ analog-to-digital converter (ADC), which acquires the filtered signal with a 24-bit resolution. Signal processing board is connected through universal serial bus interface to a personal computer, where ECS in a digital form is recorded and processed.

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.

Operation management of daily economic dispatch using novel hybrid particle swarm optimization and gravitational search algorithm with hybrid mutation strategy

NASA Astrophysics Data System (ADS)

Wang, Yan; Huang, Song; Ji, Zhicheng

2017-07-01

This paper presents a hybrid particle swarm optimization and gravitational search algorithm based on hybrid mutation strategy (HGSAPSO-M) to optimize economic dispatch (ED) including distributed generations (DGs) considering market-based energy pricing. A daily ED model was formulated and a hybrid mutation strategy was adopted in HGSAPSO-M. The hybrid mutation strategy includes two mutation operators, chaotic mutation, Gaussian mutation. The proposed algorithm was tested on IEEE-33 bus and results show that the approach is effective for this problem.

Application of Improved APO Algorithm in Vulnerability Assessment and Reconstruction of Microgrid

NASA Astrophysics Data System (ADS)

Xie, Jili; Ma, Hailing

2018-01-01

Artificial Physics Optimization (APO) has good global search ability and can avoid the premature convergence phenomenon in PSO algorithm, which has good stability of fast convergence and robustness. On the basis of APO of the vector model, a reactive power optimization algorithm based on improved APO algorithm is proposed for the static structure and dynamic operation characteristics of microgrid. The simulation test is carried out through the IEEE 30-bus system and the result shows that the algorithm has better efficiency and accuracy compared with other optimization algorithms.

Food system access, shopping behavior, and influences on purchasing groceries in adult Hmong living in Minnesota.

PubMed

Franzen, Lisa; Smith, Chery

2010-01-01

To investigate influences on shopping and eating behavior of Hmong adults living in St. Paul/Minneapolis, Minnesota. Conducted a mapping project, food surveys, food frequency questionnaire (FFQ), and focus groups (n = 11). Subjects were assigned to three groups. The B-TL(1) group was made up of subjects who were born in Thailand/Laos and had lived in the US < or =5 years (n = 19). The B-TL(2) group was made up of subjects who were born in Thailand/Laos, had food memories, and had lived in the US >5 years (n = 20). The B-US group was made up of subjects who were born and/or raised in the US (n = 30). Using Geographical Informational Systems software, 15 grocery stores were mapped and surveyed. Food prices were compared with the consumer price index (CPI). The FFQ assessed food consumption patterns. Focus group transcripts were evaluated for themes and coded. Degree of acculturation was assessed by adapting a previously developed instrument. The population is concentrated in St. Paul, coinciding with store density. Limited foods had CPIs and some CPIs were outdated. B-US had significantly higher levels of dietary acculturation than B-TL(2) and B-TL(1), with B-TL(2) also having a higher dietary acculturation level compared with B-TL(1). Acculturation of the Hmong into the American food system, determinants of store type, and Hmong food's having a mainstream factor were identified themes. B-US and B-TL(2) shopped at American stores more than did B-TL(1) because of convenience, one-stop shopping, and increased English fluency. Hmong foods have entered the American food system and are sold at Asian and American stores.

Individual welfare maximization in electricity markets including consumer and full transmission system modeling

NASA Astrophysics Data System (ADS)

Weber, James Daniel

1999-11-01

This dissertation presents a new algorithm that allows a market participant to maximize its individual welfare in the electricity spot market. The use of such an algorithm in determining market equilibrium points, called Nash equilibria, is also demonstrated. The start of the algorithm is a spot market model that uses the optimal power flow (OPF), with a full representation of the transmission system. The OPF is also extended to model consumer behavior, and a thorough mathematical justification for the inclusion of the consumer model in the OPF is presented. The algorithm utilizes price and dispatch sensitivities, available from the Hessian matrix of the OPF, to help determine an optimal change in an individual's bid. The algorithm is shown to be successful in determining local welfare maxima, and the prospects for scaling the algorithm up to realistically sized systems are very good. Assuming a market in which all participants maximize their individual welfare, economic equilibrium points, called Nash equilibria, are investigated. This is done by iteratively solving the individual welfare maximization algorithm for each participant until a point is reached where all individuals stop modifying their bids. It is shown that these Nash equilibria can be located in this manner. However, it is also demonstrated that equilibria do not always exist, and are not always unique when they do exist. It is also shown that individual welfare is a highly nonconcave function resulting in many local maxima. As a result, a more global optimization technique, using a genetic algorithm (GA), is investigated. The genetic algorithm is successfully demonstrated on several systems. It is also shown that a GA can be developed using special niche methods, which allow a GA to converge to several local optima at once. Finally, the last chapter of this dissertation covers the development of a new computer visualization routine for power system analysis: contouring. The contouring algorithm is demonstrated to be useful in visualizing bus-based and transmission line-based quantities.

Decision Support for Environmental Management of Industrial Non-Hazardous Secondary Materials: New Analytical Methods Combined with Simulation and Optimization Modeling

EPA Science Inventory

Non-hazardous solid materials from industrial processes, once regarded as waste and disposed in landfills, offer numerous environmental and economic advantages when put to beneficial uses (BUs). Proper management of these industrial non-hazardous secondary materials (INSM) requir...

A Three-Stage Enhanced Reactive Power and Voltage Optimization Method for High Penetration of Solar

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

Ke, Xinda; Huang, Renke; Vallem, Mallikarjuna R.

This paper presents a three-stage enhanced volt/var optimization method to stabilize voltage fluctuations in transmission networks by optimizing the usage of reactive power control devices. In contrast with existing volt/var optimization algorithms, the proposed method optimizes the voltage profiles of the system, while keeping the voltage and real power output of the generators as close to the original scheduling values as possible. This allows the method to accommodate realistic power system operation and market scenarios, in which the original generation dispatch schedule will not be affected. The proposed method was tested and validated on a modified IEEE 118-bus system withmore » photovoltaic data.« less

Start-Stop Moment Optimization of Range Extender and Control Strategy Design for Extended -Range Electric Vehicle

NASA Astrophysics Data System (ADS)

Zhao, Jing-bo; Han, Bing-yuan; Bei, Shao-yi

2017-10-01

Range extender is the core component of E-REV, its start-stop control determines the operation modes of vehicle. This paper based on a certain type of E-REV, researched constant power control strategy of range extender in extended-range model, to target range as constraint condition, combined with different driving cycle conditions, by correcting battery SOC for range extender start-stop moment, optimized the control strategy of range extender, and established the vehicle and range extender start-stop control simulation model. Selected NEDC and UDDS conditions simulation results show that: under certain target mileage, the range extender running time reduced by 37.2% and 28.2% in the NEDC condition, and running time UDDS conditions were reduced by 40.6% and 33.5% in the UDDS condition, reached the purpose of meeting the vehicle mileage and reducing consumption and emission.

Energy storage requirements of dc microgrids with high penetration renewables under droop control

DOE PAGES

Weaver, Wayne W.; Robinett, Rush D.; Parker, Gordon G.; ...

2015-01-09

Energy storage is a important design component in microgrids with high penetration renewable sources to maintain the system because of the highly variable and sometimes stochastic nature of the sources. Storage devices can be distributed close to the sources and/or at the microgrid bus. In addition, storage requirements can be minimized with a centralized control architecture, but this creates a single point of failure. Distributed droop control enables a completely decentralized architecture but, the energy storage optimization becomes more difficult. Our paper presents an approach to droop control that enables the local and bus storage requirements to be determined. Givenmore » a priori knowledge of the design structure of a microgrid and the basic cycles of the renewable sources, we found that the droop settings of the sources are such that they minimize both the bus voltage variations and overall energy storage capacity required in the system. This approach can be used in the design phase of a microgrid with a decentralized control structure to determine appropriate droop settings as well as the sizing of energy storage devices.« less

An input-to-state stability approach to verify almost global stability of a synchronous-machine-infinite-bus system.

PubMed

Schiffer, Johannes; Efimov, Denis; Ortega, Romeo; Barabanov, Nikita

2017-08-13

Conditions for almost global stability of an operating point of a realistic model of a synchronous generator with constant field current connected to an infinite bus are derived. The analysis is conducted by employing the recently proposed concept of input-to-state stability (ISS)-Leonov functions, which is an extension of the powerful cell structure principle developed by Leonov and Noldus to the ISS framework. Compared with the original ideas of Leonov and Noldus, the ISS-Leonov approach has the advantage of providing additional robustness guarantees. The efficiency of the derived sufficient conditions is illustrated via numerical experiments.This article is part of the themed issue 'Energy management: flexibility, risk and optimization'. © 2017 The Author(s).

Implications of optimization cost for balancing exploration and exploitation in global search and for experimental optimization

NASA Astrophysics Data System (ADS)

Chaudhuri, Anirban

Global optimization based on expensive and time consuming simulations or experiments usually cannot be carried out to convergence, but must be stopped because of time constraints, or because the cost of the additional function evaluations exceeds the benefits of improving the objective(s). This dissertation sets to explore the implications of such budget and time constraints on the balance between exploration and exploitation and the decision of when to stop. Three different aspects are considered in terms of their effects on the balance between exploration and exploitation: 1) history of optimization, 2) fixed evaluation budget, and 3) cost as a part of objective function. To this end, this research develops modifications to the surrogate-based optimization technique, Efficient Global Optimization algorithm, that controls better the balance between exploration and exploitation, and stopping criteria facilitated by these modifications. Then the focus shifts to examining experimental optimization, which shares the issues of cost and time constraints. Through a study on optimization of thrust and power for a small flapping wing for micro air vehicles, important differences and similarities between experimental and simulation-based optimization are identified. The most important difference is that reduction of noise in experiments becomes a major time and cost issue, and a second difference is that parallelism as a way to cut cost is more challenging. The experimental optimization reveals the tendency of the surrogate to display optimistic bias near the surrogate optimum, and this tendency is then verified to also occur in simulation based optimization.

A heuristic statistical stopping rule for iterative reconstruction in emission tomography.

PubMed

Ben Bouallègue, F; Crouzet, J F; Mariano-Goulart, D

2013-01-01

We propose a statistical stopping criterion for iterative reconstruction in emission tomography based on a heuristic statistical description of the reconstruction process. The method was assessed for MLEM reconstruction. Based on Monte-Carlo numerical simulations and using a perfectly modeled system matrix, our method was compared with classical iterative reconstruction followed by low-pass filtering in terms of Euclidian distance to the exact object, noise, and resolution. The stopping criterion was then evaluated with realistic PET data of a Hoffman brain phantom produced using the GATE platform for different count levels. The numerical experiments showed that compared with the classical method, our technique yielded significant improvement of the noise-resolution tradeoff for a wide range of counting statistics compatible with routine clinical settings. When working with realistic data, the stopping rule allowed a qualitatively and quantitatively efficient determination of the optimal image. Our method appears to give a reliable estimation of the optimal stopping point for iterative reconstruction. It should thus be of practical interest as it produces images with similar or better quality than classical post-filtered iterative reconstruction with a mastered computation time.

Test apparatus for locating shorts during assembly of electrical buses

NASA Technical Reports Server (NTRS)

Deboo, G. J.; Devine, D. L. (Inventor)

1981-01-01

A test apparatus is described for locating electrical shorts that is especially suited for use while an electrical circuit is being fabricated or assembled. A ring counter derives input pulses from a square wave oscillator. The outputs of the counter are fed through transistors to an array of light emitting diodes. Each diode is connected to an electrical conductor, such as a bus bar, that is to be tested. In the absence of a short between the electrical conductors the diodes are sequentially illuminated. When a short occurs, a comparator/multivibrator circuit triggers an alarm and stops the oscillator and the sequential energization of the diodes. The two diodes that remain illuminated identify the electrical conductors that are shorted.

Impact of a pilot walking school bus intervention on children's pedestrian safety behaviors: a pilot study.

PubMed

Mendoza, Jason A; Watson, Kathy; Chen, Tzu-An; Baranowski, Tom; Nicklas, Theresa A; Uscanga, Doris K; Hanfling, Marcus J

2012-01-01

Walking school buses (WSB) increased children's physical activity, but impact on pedestrian safety behaviors (PSB) is unknown. We tested the feasibility of a protocol evaluating changes to PSB during a WSB program. Outcomes were school-level street crossing PSB prior to (Time 1) and during weeks 4-5 (Time 2) of the WSB. The protocol collected 1252 observations at Time 1 and 2548 at Time 2. Mixed model analyses yielded: intervention schoolchildren had 5-fold higher odds (p<0.01) of crossing at the corner/crosswalk but 5-fold lower odds (p<0.01) of stopping at the curb. The protocol appears feasible for documenting changes to school-level PSB. Copyright © 2011 Elsevier Ltd. All rights reserved.

Modelling and Optimization of Four-Segment Shielding Coils of Current Transformers

PubMed Central

Gao, Yucheng; Zhao, Wei; Wang, Qing; Qu, Kaifeng; Li, He; Shao, Haiming; Huang, Songling

2017-01-01

Applying shielding coils is a practical way to protect current transformers (CTs) for large-capacity generators from the intensive magnetic interference produced by adjacent bus-bars. The aim of this study is to build a simple analytical model for the shielding coils, from which the optimization of the shielding coils can be calculated effectively. Based on an existing stray flux model, a new analytical model for the leakage flux of partial coils is presented, and finite element method-based simulations are carried out to develop empirical equations for the core-pickup factors of the models. Using the flux models, a model of the common four-segment shielding coils is derived. Furthermore, a theoretical analysis is carried out on the optimal performance of the four-segment shielding coils in a typical six-bus-bars scenario. It turns out that the “all parallel” shielding coils with a 45° starting position have the best shielding performance, whereas the “separated loop” shielding coils with a 0° starting position feature the lowest heating value. Physical experiments were performed, which verified all the models and the conclusions proposed in the paper. In addition, for shielding coils with other than the four-segment configuration, the analysis process will generally be the same. PMID:28587137

Modelling and Optimization of Four-Segment Shielding Coils of Current Transformers.

PubMed

Gao, Yucheng; Zhao, Wei; Wang, Qing; Qu, Kaifeng; Li, He; Shao, Haiming; Huang, Songling

2017-05-26

Applying shielding coils is a practical way to protect current transformers (CTs) for large-capacity generators from the intensive magnetic interference produced by adjacent bus-bars. The aim of this study is to build a simple analytical model for the shielding coils, from which the optimization of the shielding coils can be calculated effectively. Based on an existing stray flux model, a new analytical model for the leakage flux of partial coils is presented, and finite element method-based simulations are carried out to develop empirical equations for the core-pickup factors of the models. Using the flux models, a model of the common four-segment shielding coils is derived. Furthermore, a theoretical analysis is carried out on the optimal performance of the four-segment shielding coils in a typical six-bus-bars scenario. It turns out that the "all parallel" shielding coils with a 45° starting position have the best shielding performance, whereas the "separated loop" shielding coils with a 0° starting position feature the lowest heating value. Physical experiments were performed, which verified all the models and the conclusions proposed in the paper. In addition, for shielding coils with other than the four-segment configuration, the analysis process will generally be the same.

Reactive power planning under high penetration of wind energy using Benders decomposition

DOE PAGES

Xu, Yan; Wei, Yanli; Fang, Xin; ...

2015-11-05

This study addresses the optimal allocation of reactive power volt-ampere reactive (VAR) sources under the paradigm of high penetration of wind energy. Reactive power planning (RPP) in this particular condition involves a high level of uncertainty because of wind power characteristic. To properly model wind generation uncertainty, a multi-scenario framework optimal power flow that considers the voltage stability constraint under the worst wind scenario and transmission N 1 contingency is developed. The objective of RPP in this study is to minimise the total cost including the VAR investment cost and the expected generation cost. Therefore RPP under this condition ismore » modelled as a two-stage stochastic programming problem to optimise the VAR location and size in one stage, then to minimise the fuel cost in the other stage, and eventually, to find the global optimal RPP results iteratively. Benders decomposition is used to solve this model with an upper level problem (master problem) for VAR allocation optimisation and a lower problem (sub-problem) for generation cost minimisation. Impact of the potential reactive power support from doubly-fed induction generator (DFIG) is also analysed. Lastly, case studies on the IEEE 14-bus and 118-bus systems are provided to verify the proposed method.« less

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.

Breast ultrasound image segmentation: an optimization approach based on super-pixels and high-level descriptors

NASA Astrophysics Data System (ADS)

Massich, Joan; Lemaître, Guillaume; Martí, Joan; Mériaudeau, Fabrice

2015-04-01

Breast cancer is the second most common cancer and the leading cause of cancer death among women. Medical imaging has become an indispensable tool for its diagnosis and follow up. During the last decade, the medical community has promoted to incorporate Ultra-Sound (US) screening as part of the standard routine. The main reason for using US imaging is its capability to differentiate benign from malignant masses, when compared to other imaging techniques. The increasing usage of US imaging encourages the development of Computer Aided Diagnosis (CAD) systems applied to Breast Ultra-Sound (BUS) images. However accurate delineations of the lesions and structures of the breast are essential for CAD systems in order to extract information needed to perform diagnosis. This article proposes a highly modular and flexible framework for segmenting lesions and tissues present in BUS images. The proposal takes advantage of optimization strategies using super-pixels and high-level descriptors, which are analogous to the visual cues used by radiologists. Qualitative and quantitative results are provided stating a performance within the range of the state-of-the-art.

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.

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

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

PubMed Central

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

2014-01-01

A dual-motor coupling-propulsion electric bus (DMCPEB) is modeled, and its optimal control strategy is studied in this paper. The necessary dynamic features of energy loss for subsystems is modeled. Dynamic programming (DP) technique is applied to find the optimal control strategy including upshift threshold, downshift threshold, and power split ratio between the main motor and auxiliary motor. Improved control rules are extracted from the DP-based control solution, forming near-optimal control strategies. Simulation results demonstrate that a significant improvement in reducing energy loss due to the dual-motor coupling-propulsion system (DMCPS) running is realized without increasing the frequency of the mode switch. PMID:25540814

Optimal control strategy design based on dynamic programming for a dual-motor coupling-propulsion system.

PubMed

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

2014-01-01

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

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.

Continuation Power Flow with Variable-Step Variable-Order Nonlinear Predictor

NASA Astrophysics Data System (ADS)

Kojima, Takayuki; Mori, Hiroyuki

This paper proposes a new continuation power flow calculation method for drawing a P-V curve in power systems. The continuation power flow calculation successively evaluates power flow solutions through changing a specified value of the power flow calculation. In recent years, power system operators are quite concerned with voltage instability due to the appearance of deregulated and competitive power markets. The continuation power flow calculation plays an important role to understand the load characteristics in a sense of static voltage instability. In this paper, a new continuation power flow with a variable-step variable-order (VSVO) nonlinear predictor is proposed. The proposed method evaluates optimal predicted points confirming with the feature of P-V curves. The proposed method is successfully applied to IEEE 118-bus and IEEE 300-bus systems.

A rapid and simple pretreatment method for benzoylurea insecticides in honey samples using in-syringe dispersive liquid-liquid microextraction based on the direct solidification of ionic liquids.

PubMed

Wang, Huazi; Hu, Lu; Li, Wanzhen; Lu, Runhua; Zhang, Sanbing; Zhou, Wenfeng; Gao, Haixiang

2016-11-04

A pretreatment method using in-syringe dispersive liquid-liquid microextraction based on the direct solidification of ionic liquids before high performance liquid chromatography analysis was developed for the determination of benzoylurea insecticides (BUs) in honey samples. The hydrophobic ionic liquid [N 4444 ][PF 6 ], formed in situ by the hydrophilic ionic liquid [N 4444 ]Cl and the ion exchange reagent KPF 6 , was used to extract the target analytes. The entire extraction procedure was performed in a syringe. The extractant was solidified at room temperature and collected using a nylon membrane filter. This technique did not require a dispersive solvent, vortex mixer, ultrasound bath, or centrifugation. The parameters affecting the extraction efficiency were investigated through an experimental design. Under the optimal conditions, the limits of detection for the four BUs varied from 0.21 to 0.42μgL -1 in solution (2.1-4.2μgkg -1 in honey). Good linearities were obtained in the range of 2-300μgL -1 , with coefficients of determination greater than 0.999. The recoveries of the four BUs ranged from 80.94% to 84.59%. The intra-day (n=3) and inter-day (n=3) relative standard deviations were less than 5.08%. Finally, the proposed method was applied to the determination of BUs in commercial honey samples with satisfactory results. Copyright © 2016 Elsevier B.V. All rights reserved.

Rational decision-making in inhibitory control.

PubMed

Shenoy, Pradeep; Yu, Angela J

2011-01-01

An important aspect of cognitive flexibility is inhibitory control, the ability to dynamically modify or cancel planned actions in response to changes in the sensory environment or task demands. We formulate a probabilistic, rational decision-making framework for inhibitory control in the stop signal paradigm. Our model posits that subjects maintain a Bayes-optimal, continually updated representation of sensory inputs, and repeatedly assess the relative value of stopping and going on a fine temporal scale, in order to make an optimal decision on when and whether to go on each trial. We further posit that they implement this continual evaluation with respect to a global objective function capturing the various reward and penalties associated with different behavioral outcomes, such as speed and accuracy, or the relative costs of stop errors and go errors. We demonstrate that our rational decision-making model naturally gives rise to basic behavioral characteristics consistently observed for this paradigm, as well as more subtle effects due to contextual factors such as reward contingencies or motivational factors. Furthermore, we show that the classical race model can be seen as a computationally simpler, perhaps neurally plausible, approximation to optimal decision-making. This conceptual link allows us to predict how the parameters of the race model, such as the stopping latency, should change with task parameters and individual experiences/ability.

Rational Decision-Making in Inhibitory Control

PubMed Central

Shenoy, Pradeep; Yu, Angela J.

2011-01-01

An important aspect of cognitive flexibility is inhibitory control, the ability to dynamically modify or cancel planned actions in response to changes in the sensory environment or task demands. We formulate a probabilistic, rational decision-making framework for inhibitory control in the stop signal paradigm. Our model posits that subjects maintain a Bayes-optimal, continually updated representation of sensory inputs, and repeatedly assess the relative value of stopping and going on a fine temporal scale, in order to make an optimal decision on when and whether to go on each trial. We further posit that they implement this continual evaluation with respect to a global objective function capturing the various reward and penalties associated with different behavioral outcomes, such as speed and accuracy, or the relative costs of stop errors and go errors. We demonstrate that our rational decision-making model naturally gives rise to basic behavioral characteristics consistently observed for this paradigm, as well as more subtle effects due to contextual factors such as reward contingencies or motivational factors. Furthermore, we show that the classical race model can be seen as a computationally simpler, perhaps neurally plausible, approximation to optimal decision-making. This conceptual link allows us to predict how the parameters of the race model, such as the stopping latency, should change with task parameters and individual experiences/ability. PMID:21647306

A Status report to the Superintendent of Public Instruction on a study of optimal school bus speed limits on Virginia highways.

DOT National Transportation Integrated Search

1988-01-01

The study was prompted by the fact that on Virginia's rural interstate highways there is a three-tiered speed limit: 45 mph for school buses, 55 mph for other buses and trucks, and 65 mph for passenger vehicles. On the urban interstate system, school...

Parallel Harmony Search Based Distributed Energy Resource Optimization

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

Ceylan, Oguzhan; Liu, Guodong; Tomsovic, Kevin

2015-01-01

This paper presents a harmony search based parallel optimization algorithm to minimize voltage deviations in three phase unbalanced electrical distribution systems and to maximize active power outputs of distributed energy resources (DR). The main contribution is to reduce the adverse impacts on voltage profile during a day as photovoltaics (PVs) output or electrical vehicles (EVs) charging changes throughout a day. The IEEE 123- bus distribution test system is modified by adding DRs and EVs under different load profiles. The simulation results show that by using parallel computing techniques, heuristic methods may be used as an alternative optimization tool in electricalmore » power distribution systems operation.« less

Optimally stopped variational quantum algorithms

NASA Astrophysics Data System (ADS)

Vinci, Walter; Shabani, Alireza

2018-04-01

Quantum processors promise a paradigm shift in high-performance computing which needs to be assessed by accurate benchmarking measures. In this article, we introduce a benchmark for the variational quantum algorithm (VQA), recently proposed as a heuristic algorithm for small-scale quantum processors. In VQA, a classical optimization algorithm guides the processor's quantum dynamics to yield the best solution for a given problem. A complete assessment of the scalability and competitiveness of VQA should take into account both the quality and the time of dynamics optimization. The method of optimal stopping, employed here, provides such an assessment by explicitly including time as a cost factor. Here, we showcase this measure for benchmarking VQA as a solver for some quadratic unconstrained binary optimization. Moreover, we show that a better choice for the cost function of the classical routine can significantly improve the performance of the VQA algorithm and even improve its scaling properties.

An optimal autonomous microgrid cluster based on distributed generation droop parameter optimization and renewable energy sources using an improved grey wolf optimizer

NASA Astrophysics Data System (ADS)

Moazami Goodarzi, Hamed; Kazemi, Mohammad Hosein

2018-05-01

Microgrid (MG) clustering is regarded as an important driver in improving the robustness of MGs. However, little research has been conducted on providing appropriate MG clustering. This article addresses this shortfall. It proposes a novel multi-objective optimization approach for finding optimal clustering of autonomous MGs by focusing on variables such as distributed generation (DG) droop parameters, the location and capacity of DG units, renewable energy sources, capacitors and powerline transmission. Power losses are minimized and voltage stability is improved while virtual cut-set lines with minimum power transmission for clustering MGs are obtained. A novel chaotic grey wolf optimizer (CGWO) algorithm is applied to solve the proposed multi-objective problem. The performance of the approach is evaluated by utilizing a 69-bus MG in several scenarios.

Optimal Operation and Dispatch of Voltage Regulation Devices Considering High Penetrations of Distributed Photovoltaic Generation

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

Mather, Barry A; Hodge, Brian S; Cho, Gyu-Jung

Voltage regulation devices have been traditionally installed and utilized to support distribution voltages. Installations of distributed energy resources (DERs) in distribution systems are rapidly increasing, and many of these generation resources have variable and uncertain power output. These generators can significantly change the voltage profile for a feeder; therefore, in the distribution system planning stage of the optimal operation and dispatch of voltage regulation devices, possible high penetrations of DERs should be considered. In this paper, we model the IEEE 34-bus test feeder, including all essential equipment. An optimization method is adopted to determine the optimal siting and operation ofmore » the voltage regulation devices in the presence of distributed solar power generation. Finally, we verify the optimal configuration of the entire system through the optimization and simulation results.« less

Lessons Learned in a Breastfeeding Media Campaign.

PubMed

Ware, Julie L; Mzayek, Fawaz; Levy, Marian

2016-09-01

Breastfeeding is well accepted as the optimal nutrition for babies. The American Academy of Pediatrics states that infant feeding should no longer be thought of as a lifestyle choice, but rather as a public health issue. In Shelby County, Tennessee, rates of breastfeeding continue to be disparately low. To address this public health problem, a focus group study was conducted with the Shelby County population least likely to breastfeed. Following participants' suggestion to use a billboard campaign with pictures of local mothers and families, one highway billboard and ten bus stop signs were placed around the city in areas of the lowest breastfeeding rates. Self-administered surveys were completed by convenience sampling in target population areas with women least likely to breastfeed, both before placing the signs and 6 months later. No significant differences were noted in knowledge, attitudes, or practices after the media campaign, but trends toward increased intention to breastfeed were noted among expectant mothers. With collapsed data (pre and post), a majority of participants believed that breastfeeding is the best way to feed a baby and they were significantly more likely to plan to breastfeed if they knew about health benefits to the baby and to themselves. If they had heard about breastfeeding on the TV or radio, they were more likely to believe breastfeeding is important for long-term health. These findings suggest that a media campaign could have a complementary role in promoting breastfeeding among women with low initiation rates.

Irrelevance of the Power Stroke for the Directionality, Stopping Force, and Optimal Efficiency of Chemically Driven Molecular Machines

PubMed Central

Astumian, R. Dean

2015-01-01

A simple model for a chemically driven molecular walker shows that the elastic energy stored by the molecule and released during the conformational change known as the power-stroke (i.e., the free-energy difference between the pre- and post-power-stroke states) is irrelevant for determining the directionality, stopping force, and efficiency of the motor. Further, the apportionment of the dependence on the externally applied force between the forward and reverse rate constants of the power-stroke (or indeed among all rate constants) is irrelevant for determining the directionality, stopping force, and efficiency of the motor. Arguments based on the principle of microscopic reversibility demonstrate that this result is general for all chemically driven molecular machines, and even more broadly that the relative energies of the states of the motor have no role in determining the directionality, stopping force, or optimal efficiency of the machine. Instead, the directionality, stopping force, and optimal efficiency are determined solely by the relative heights of the energy barriers between the states. Molecular recognition—the ability of a molecular machine to discriminate between substrate and product depending on the state of the machine—is far more important for determining the intrinsic directionality and thermodynamics of chemo-mechanical coupling than are the details of the internal mechanical conformational motions of the machine. In contrast to the conclusions for chemical driving, a power-stroke is very important for the directionality and efficiency of light-driven molecular machines and for molecular machines driven by external modulation of thermodynamic parameters. PMID:25606678

Coordinated Optimization of Distributed Energy Resources and Smart Loads in Distribution Systems: Preprint

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

Yang, Rui; Zhang, Yingchen

2016-08-01

Distributed energy resources (DERs) and smart loads have the potential to provide flexibility to the distribution system operation. A coordinated optimization approach is proposed in this paper to actively manage DERs and smart loads in distribution systems to achieve the optimal operation status. A three-phase unbalanced Optimal Power Flow (OPF) problem is developed to determine the output from DERs and smart loads with respect to the system operator's control objective. This paper focuses on coordinating PV systems and smart loads to improve the overall voltage profile in distribution systems. Simulations have been carried out in a 12-bus distribution feeder andmore » results illustrate the superior control performance of the proposed approach.« less

Coordinated Optimization of Distributed Energy Resources and Smart Loads in Distribution Systems

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

Yang, Rui; Zhang, Yingchen

2016-11-14

Distributed energy resources (DERs) and smart loads have the potential to provide flexibility to the distribution system operation. A coordinated optimization approach is proposed in this paper to actively manage DERs and smart loads in distribution systems to achieve the optimal operation status. A three-phase unbalanced Optimal Power Flow (OPF) problem is developed to determine the output from DERs and smart loads with respect to the system operator's control objective. This paper focuses on coordinating PV systems and smart loads to improve the overall voltage profile in distribution systems. Simulations have been carried out in a 12-bus distribution feeder andmore » results illustrate the superior control performance of the proposed approach.« less

Investigating Geosparql Requirements for Participatory Urban Planning

NASA Astrophysics Data System (ADS)

Mohammadi, E.; Hunter, A. J. S.

2015-06-01

We propose that participatory GIS (PGIS) activities including participatory urban planning can be made more efficient and effective if spatial reasoning rules are integrated with PGIS tools to simplify engagement for public contributors. Spatial reasoning is used to describe relationships between spatial entities. These relationships can be evaluated quantitatively or qualitatively using geometrical algorithms, ontological relations, and topological methods. Semantic web services utilize tools and methods that can facilitate spatial reasoning. GeoSPARQL, introduced by OGC, is a spatial reasoning standard used to make declarations about entities (graphical contributions) that take the form of a subject-predicate-object triple or statement. GeoSPARQL uses three basic methods to infer topological relationships between spatial entities, including: OGC's simple feature topology, RCC8, and the DE-9IM model. While these methods are comprehensive in their ability to define topological relationships between spatial entities, they are often inadequate for defining complex relationships that exist in the spatial realm. Particularly relationships between urban entities, such as those between a bus route, the collection of associated bus stops and their overall surroundings as an urban planning pattern. In this paper we investigate common qualitative spatial reasoning methods as a preliminary step to enhancing the capabilities of GeoSPARQL in an online participatory GIS framework in which reasoning is used to validate plans based on standard patterns that can be found in an efficient/effective urban environment.

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...

A Living Laboratory for Energy Systems Integration - Continuum Magazine |

Science.gov Websites

research centers across NREL to study how to optimize the campus's energy use. The Energy DataBus The , at second-by-second intervals, 24 hours per day, and stores it all in one giant database. And the use solution that is designed for large, scalable databases. "It's similar to the one that Facebook and

Decision Support for Environmental Management of Industrial ...

EPA Pesticide Factsheets

Non-hazardous solid materials from industrial processes, once regarded as waste and disposed in landfills, offer numerous environmental and economic advantages when put to beneficial uses (BUs). Proper management of these industrial non-hazardous secondary materials (INSM) requires estimates of their probable environmental impacts among disposal as well as BU options. The U.S. Environmental Protection Agency (EPA) has recently approved new analytical methods (EPA Methods 1313–1316) to assess leachability of constituents of potential concern in these materials. These new methods are more realistic for many disposal and BU options than historical methods, such as the toxicity characteristic leaching protocol. Experimental data from these new methods are used to parameterize a chemical fate and transport (F&T) model to simulate long-term environmental releases from flue gas desulfurization gypsum (FGDG) when disposed of in an industrial landfill or beneficially used as an agricultural soil amendment. The F&T model is also coupled with optimization algorithms, the Beneficial Use Decision Support System (BUDSS), under development by EPA to enhance INSM management. The objective of this paper is to demonstrate the methodologies and encourage similar applications to improve environmental management and BUs of INSM through F&T simulation coupled with optimization, using realistic model parameterization.

Spatial-Temporal Synchrophasor Data Characterization and Analytics in Smart Grid Fault Detection, Identification, and Impact Causal Analysis

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

Jiang, Huaiguang; Dai, Xiaoxiao; Gao, David Wenzhong

An approach of big data characterization for smart grids (SGs) and its applications in fault detection, identification, and causal impact analysis is proposed in this paper, which aims to provide substantial data volume reduction while keeping comprehensive information from synchrophasor measurements in spatial and temporal domains. Especially, based on secondary voltage control (SVC) and local SG observation algorithm, a two-layer dynamic optimal synchrophasor measurement devices selection algorithm (OSMDSA) is proposed to determine SVC zones, their corresponding pilot buses, and the optimal synchrophasor measurement devices. Combining the two-layer dynamic OSMDSA and matching pursuit decomposition, the synchrophasor data is completely characterized inmore » the spatial-temporal domain. To demonstrate the effectiveness of the proposed characterization approach, SG situational awareness is investigated based on hidden Markov model based fault detection and identification using the spatial-temporal characteristics generated from the reduced data. To identify the major impact buses, the weighted Granger causality for SGs is proposed to investigate the causal relationship of buses during system disturbance. The IEEE 39-bus system and IEEE 118-bus system are employed to validate and evaluate the proposed approach.« less

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...

On-road PM2.5 pollution exposure in multiple transport microenvironments in Delhi

NASA Astrophysics Data System (ADS)

Goel, Rahul; Gani, Shahzad; Guttikunda, Sarath K.; Wilson, Daniel; Tiwari, Geetam

2015-12-01

PM2.5 pollution in Delhi averaged 150 μg/m3 from 2012 through 2014, which is 15 times higher than the World Health Organization's annual-average guideline. For this setting, we present on-road exposure of PM2.5 concentrations for 11 transport microenvironments along a fixed 8.3-km arterial route, during morning rush hour. The data collection was carried out using a portable TSI DustTrak DRX 8433 aerosol monitor, between January and May (2014). The monthly-average measured ambient concentrations varied from 130 μg/m3 to 250 μg/m3. The on-road PM2.5 concentrations exceeded the ambient measurements by an average of 40% for walking, 10% for cycle, 30% for motorised two wheeler (2W), 30% for open-windowed (OW) car, 30% for auto rickshaw, 20% for air-conditioned as well as for OW bus, 20% for bus stop, and 30% for underground metro station. On the other hand, concentrations were lower by 50% inside air-conditioned (AC) car and 20% inside the metro rail carriage. We find that the percent exceedance for open modes (cycle, auto rickshaw, 2W, OW car, and OW bus) reduces non-linearly with increasing ambient concentration. The reduction is steeper at concentrations lower than 150 μg/m3 than at higher concentrations. After accounting for air inhalation rate and speed of travel, PM2.5 mass uptake per kilometer during cycling is 9 times of AC car, the mode with the lowest exposure. At current level of concentrations, an hour of cycling in Delhi during morning rush-hour period results in PM2.5 dose which is 40% higher than an entire-day dose in cities like Tokyo, London, and New York, where ambient concentrations range from 10 to 20 μg/m3.

Characteristics of cabin air quality in school buses in Central Texas

NASA Astrophysics Data System (ADS)

Rim, Donghyun; Siegel, Jeffrey; Spinhirne, Jarett; Webb, Alba; McDonald-Buller, Elena

This study assessed in-cabin concentrations of diesel-associated air pollutants in six school buses with diesel engines during a typical route in suburban Austin, Texas. Air exchange rates measured by SF 6 decay were 2.60-4.55 h -1. In-cabin concentrations of all pollutants measured exhibited substantial variability across the range of tests even between buses of similar age, mileage, and engine type. In-cabin NO x concentrations ranged from 44.7 to 148 ppb and were 1.3-10 times higher than roadway NO x concentrations. Mean in-cabin PM 2.5 concentrations were 7-20 μg m -3 and were generally lower than roadway levels. In-cabin concentrations exhibited higher variability during cruising mode than frequent stops. Mean in-cabin ultrafine PM number concentrations were 6100-32,000 particles cm -3 and were generally lower than roadway levels. Comparison of median concentrations indicated that in-cabin ultrafine PM number concentrations were higher than or approximately the same as the roadway concentrations, which implied that, by excluding the bias caused by local traffic, ultrafine PM levels were higher in the bus cabin than outside of the bus. Cabin pollutant concentrations on three buses were measured prior to and following the phased installation of a Donaldson Spiracle Crankcase Filtration System and a Diesel Oxidation Catalyst. Following installation of the Spiracle, the Diesel Oxidation Catalyst provided negligible or small additional reductions of in-cabin pollutant levels. In-cabin concentration decreases with the Spiracle alone ranged from 24 to 37% for NO x and 26 to 62% and 6.6 to 43% for PM 2.5 and ultrafine PM, respectively. Comparison of the ranges of PM 2.5 and ultrafine PM variations between repetitive tests suggested that retrofit installation could not always be conclusively linked to the decrease of pollutant levels in the bus cabin.

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.

Application of GPS data for benefits of air quality assessment and fleet management

NASA Astrophysics Data System (ADS)

Hao, Song; Fat Lam, Yun; Cheong Ying, Chi; Chan, Ka Lok

2017-04-01

In the modern digitizedsociety, traffic data can be easily collected for use in roadway development, urban planning and vehicle emission. These data are then further parameterized to support traffic simulation and roadside emission calculations. With the commercialization of AGPS/GPS technology, GPS data are widely utilized to study habit and travelling behaviors. GPS on franchised buses can provide not only positioning information for fleet management but also raw data to analyze traffic situations. In HK, franchised buses account for 6% of RSP and 20% of NOx emissions among the whole vehicle fleet. Being the most heavily means of public transport, the setting up of bus travelling trajectories and service frequency always raise concern from citizens. On this basis, there is an increasing interest and as well as to design and realize an effective cost benefit fleet management strategy. In this study, data collection analysis is carried out on all bus routes (i.e. 112) in Shatin district, one of the 18 districts in Hong Kong. The GPS/AGPS data through Esri ArcGIS investigate the potential benefit of GPS data in different emission scenarios (such as engine type over whole bus fleet). Building on the emission factors from EMFC-HK model, we accounted for factors like travelling distance, idling time, occupancy rate, service frequency, tire and break emissions. Through the simple emission developed model we demonstrate how GPS are data are utilized to assess bus fleet emissions. Further amelioration on the results involve tuning the model with field measurement so as to assess district level emission change after fleet optimization.

Computational Analysis and Low-Scale Constitutive Expression of Laccases Synthetic Genes GlLCC1 from Ganoderma lucidum and POXA 1B from Pleurotus ostreatus in Pichia pastoris

PubMed Central

Reyes-Guzmán, Edwin Alfredo; Poutou-Piñales, Raúl A.; Reyes-Montaño, Edgar Antonio; Pedroza-Rodríguez, Aura Marina; Rodríguez-Vázquez, Refugio; Cardozo-Bernal, Ángela M.

2015-01-01

Lacasses are multicopper oxidases that can catalyze aromatic and non-aromatic compounds concomitantly with reduction of molecular oxygen to water. Fungal laccases have generated a growing interest due to their biotechnological potential applications, such as lignocellulosic material delignification, biopulping and biobleaching, wastewater treatment, and transformation of toxic organic pollutants. In this work we selected fungal genes encoding for laccase enzymes GlLCC1 in Ganoderma lucidum and POXA 1B in Pleurotus ostreatus. These genes were optimized for codon use, GC content, and regions generating secondary structures. Laccase proposed computational models, and their interaction with ABTS [2, 2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)] substrate was evaluated by molecular docking. Synthetic genes were cloned under the control of Pichia pastoris glyceraldehyde-3-phosphate dehydrogenase (GAP) constitutive promoter. P. pastoris X-33 was transformed with pGAPZαA-LaccGluc-Stop and pGAPZαA-LaccPost-Stop constructs. Optimization reduced GC content by 47 and 49% for LaccGluc-Stop and LaccPost-Stop genes, respectively. A codon adaptation index of 0.84 was obtained for both genes. 3D structure analysis using SuperPose revealed LaccGluc-Stop is similar to the laccase crystallographic structure 1GYC of Trametes versicolor. Interaction analysis of the 3D models validated through ABTS, demonstrated higher substrate affinity for LaccPost-Stop, in agreement with our experimental results with enzymatic activities of 451.08 ± 6.46 UL-1 compared to activities of 0.13 ± 0.028 UL-1 for LaccGluc-Stop. This study demonstrated that G. lucidum GlLCC1 and P. ostreatus POXA 1B gene optimization resulted in constitutive gene expression under GAP promoter and α-factor leader in P. pastoris. These are important findings in light of recombinant enzyme expression system utility for environmentally friendly designed expression systems, because of the wide range of substrates that laccases can transform. This contributes to a great gamut of products in diverse settings: industry, clinical and chemical use, and environmental applications. PMID:25611746

Computational analysis and low-scale constitutive expression of laccases synthetic genes GlLCC1 from Ganoderma lucidum and POXA 1B from Pleurotus ostreatus in Pichia pastoris.

PubMed

Rivera-Hoyos, Claudia M; Morales-Álvarez, Edwin David; Poveda-Cuevas, Sergio Alejandro; Reyes-Guzmán, Edwin Alfredo; Poutou-Piñales, Raúl A; Reyes-Montaño, Edgar Antonio; Pedroza-Rodríguez, Aura Marina; Rodríguez-Vázquez, Refugio; Cardozo-Bernal, Ángela M

2015-01-01

Lacasses are multicopper oxidases that can catalyze aromatic and non-aromatic compounds concomitantly with reduction of molecular oxygen to water. Fungal laccases have generated a growing interest due to their biotechnological potential applications, such as lignocellulosic material delignification, biopulping and biobleaching, wastewater treatment, and transformation of toxic organic pollutants. In this work we selected fungal genes encoding for laccase enzymes GlLCC1 in Ganoderma lucidum and POXA 1B in Pleurotus ostreatus. These genes were optimized for codon use, GC content, and regions generating secondary structures. Laccase proposed computational models, and their interaction with ABTS [2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)] substrate was evaluated by molecular docking. Synthetic genes were cloned under the control of Pichia pastoris glyceraldehyde-3-phosphate dehydrogenase (GAP) constitutive promoter. P. pastoris X-33 was transformed with pGAPZαA-LaccGluc-Stop and pGAPZαA-LaccPost-Stop constructs. Optimization reduced GC content by 47 and 49% for LaccGluc-Stop and LaccPost-Stop genes, respectively. A codon adaptation index of 0.84 was obtained for both genes. 3D structure analysis using SuperPose revealed LaccGluc-Stop is similar to the laccase crystallographic structure 1GYC of Trametes versicolor. Interaction analysis of the 3D models validated through ABTS, demonstrated higher substrate affinity for LaccPost-Stop, in agreement with our experimental results with enzymatic activities of 451.08 ± 6.46 UL-1 compared to activities of 0.13 ± 0.028 UL-1 for LaccGluc-Stop. This study demonstrated that G. lucidum GlLCC1 and P. ostreatus POXA 1B gene optimization resulted in constitutive gene expression under GAP promoter and α-factor leader in P. pastoris. These are important findings in light of recombinant enzyme expression system utility for environmentally friendly designed expression systems, because of the wide range of substrates that laccases can transform. This contributes to a great gamut of products in diverse settings: industry, clinical and chemical use, and environmental applications.

Traffic signal coordination and queue management in oversaturated intersection.

DOT National Transportation Integrated Search

2011-03-18

Traffic signal timing optimization when done properly, could significantly improve network : performance by reducing delay, increasing network throughput, reducing number of stops, or : increasing average speed in the network. The optimization can be...

Traffic signal coordination and queue management in oversaturated intersections.

DOT National Transportation Integrated Search

2011-03-18

Traffic signal timing optimization when done properly, could significantly improve network performance by reducing delay, increasing network throughput, reducing number of stops, or increasing average speed in the network. The optimization can become...

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.

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.

Robust optimization-based DC optimal power flow for managing wind generation uncertainty

NASA Astrophysics Data System (ADS)

Boonchuay, Chanwit; Tomsovic, Kevin; Li, Fangxing; Ongsakul, Weerakorn

2012-11-01

Integrating wind generation into the wider grid causes a number of challenges to traditional power system operation. Given the relatively large wind forecast errors, congestion management tools based on optimal power flow (OPF) need to be improved. In this paper, a robust optimization (RO)-based DCOPF is proposed to determine the optimal generation dispatch and locational marginal prices (LMPs) for a day-ahead competitive electricity market considering the risk of dispatch cost variation. The basic concept is to use the dispatch to hedge against the possibility of reduced or increased wind generation. The proposed RO-based DCOPF is compared with a stochastic non-linear programming (SNP) approach on a modified PJM 5-bus system. Primary test results show that the proposed DCOPF model can provide lower dispatch cost than the SNP approach.

A Pause-then-Cancel model of stopping: evidence from basal ganglia neurophysiology.

PubMed

Schmidt, Robert; Berke, Joshua D

2017-04-19

Many studies have implicated the basal ganglia in the suppression of action impulses ('stopping'). Here, we discuss recent neurophysiological evidence that distinct hypothesized processes involved in action preparation and cancellation can be mapped onto distinct basal ganglia cell types and pathways. We examine how movement-related activity in the striatum is related to a 'Go' process and how going may be modulated by brief epochs of beta oscillations. We then describe how, rather than a unitary 'Stop' process, there appear to be separate, complementary 'Pause' and 'Cancel' mechanisms. We discuss the implications of these stopping subprocesses for the interpretation of the stop-signal reaction time-in particular, some activity that seems too slow to causally contribute to stopping when assuming a single Stop processes may actually be fast enough under a Pause-then-Cancel model. Finally, we suggest that combining complementary neural mechanisms that emphasize speed or accuracy respectively may serve more generally to optimize speed-accuracy trade-offs.This article is part of the themed issue 'Movement suppression: brain mechanisms for stopping and stillness'. © 2017 The Author(s).

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.

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...

STOP Analysis and Optimization of a Very-Low-Distortion Space Instrument: HST WFC3 Case Study

NASA Technical Reports Server (NTRS)

Kunt, Cengiz; Broduer, Steve (Technical Monitor)

2001-01-01

New generation optical instruments with very demanding stability requirements are being proposed and developed for space applications. STOP (Structural-Thermal-Optical Performance) analysis and optimization is crucial in meeting the very tight distortion budgets of these instruments. This presentation outlines STOP analysis and optimization approach in the context of WFC3 (Wide-Field Camera 3), which is a radial instrument designed to replace the Wide-Field Planetary Camera 2 (WFPC2) of the Hubble Space Telescope (HST). WFC3 houses two separate channels, UVIS and IR, and will have greater throughput and sensitivity than WFPC2. WFC3 line-of-sight alignment budget for the UVIS and IR channels are as small as 10 and 20 milli-arcsec, respectively. Its optical bench is the most critical subsystem effecting the optical stability of WFC3 hence our effort concentrates on the design and analysis of the bench and its interfaces. Structural analysis has accompanied the mechanical design of the bench since the initial concept study. A high fidelity structural Finite Element Model (FEM) of the bench has been developed and used for minimizing its thermally induced distortions as well as sizing it to meet the stiffness and strength requirements of a Shuttle launch. The bench is a composite honeycomb panel box structure with a very low planar Coefficient of Thermal Expansion (CTE) of approximately 0.1 ppm/C. Optic components are mounted to super-INVAR inserts bonded into the panels. The bench is kinematically supported on three HST latches via interface struts, which are tailored to exhibit negative CTE to cancel out the thermal motions of the latches. The interface struts also incorporate flexure elements to minimize the mechanical distortions coming into the bench from its enclosure. Bench FEM is coupled with the enclosure FEM to quantify these effects. Short term or on-orbit STOP analysis includes distortion due to the temperature variations of the bench, the struts, and the enclosure. Long term or ground-to-orbit STOP analysis includes distortional effects of gravity release, desorption, and assembly in addition to the ground-to-orbit temperature variations. A rigorous testing program has been implemented for verifying the material properties and the analysis predictions. STOP analysis results demonstrate that both the short-term and the long-term alignment budgets will be met. Presentation will cover design and analysis details that are critical to a successful implementation of the STOP analysis and optimization process.

Optimal Control of Connected and Automated Vehicles at Roundabouts

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

Zhao, Liuhui; Malikopoulos, Andreas; Rios-Torres, Jackeline

Connectivity and automation in vehicles provide the most intriguing opportunity for enabling users to better monitor transportation network conditions and make better operating decisions to improve safety and reduce pollution, energy consumption, and travel delays. This study investigates the implications of optimally coordinating vehicles that are wirelessly connected to each other and to an infrastructure in roundabouts to achieve a smooth traffic flow without stop-and-go driving. We apply an optimization framework and an analytical solution that allows optimal coordination of vehicles for merging in such traffic scenario. The effectiveness of the efficiency of the proposed approach is validated through simulationmore » and it is shown that coordination of vehicles can reduce total travel time by 3~49% and fuel consumption by 2~27% with respect to different traffic levels. In addition, network throughput is improved by up to 25% due to elimination of stop-and-go driving behavior.« less

Voronoi Diagram Based Optimization of Dynamic Reactive Power Sources

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

Huang, Weihong; Sun, Kai; Qi, Junjian

2015-01-01

Dynamic var sources can effectively mitigate fault-induced delayed voltage recovery (FIDVR) issues or even voltage collapse. This paper proposes a new approach to optimization of the sizes of dynamic var sources at candidate locations by a Voronoi diagram based algorithm. It first disperses sample points of potential solutions in a searching space, evaluates a cost function at each point by barycentric interpolation for the subspaces around the point, and then constructs a Voronoi diagram about cost function values over the entire space. Accordingly, the final optimal solution can be obtained. Case studies on the WSCC 9-bus system and NPCC 140-busmore » system have validated that the new approach can quickly identify the boundary of feasible solutions in searching space and converge to the global optimal solution.« less

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.

Domain Wall Fermion Inverter on Pentium 4

NASA Astrophysics Data System (ADS)

Pochinsky, Andrew

2005-03-01

A highly optimized domain wall fermion inverter has been developed as part of the SciDAC lattice initiative. By designing the code to minimize memory bus traffic, it achieves high cache reuse and performance in excess of 2 GFlops for out of L2 cache problem sizes on a GigE cluster with 2.66 GHz Xeon processors. The code uses the SciDAC QMP communication library.

Cloud Computing Solutions for the Marine Corps: An Architecture to Support Expeditionary Logistics

DTIC Science & Technology

2013-09-01

reform IT financial , acquisition, and contracting practices (Takai, 2012). The second step is to optimize data center consolidation . Kundra (2010...the U.S. Government. IRB Protocol number ____N/A____. 12a. DISTRIBUTION / AVAILABILITY STATEMENT Approved for public release;distribution is...USB universal serial bus USMCELC United States Marine Corps Expeditionary Logistics Cloud UUNS urgent universal needs statement xix VA volt

Ringfield lithographic camera

DOEpatents

Sweatt, W.C.

1998-09-08

A projection lithography camera is presented with a wide ringfield optimized so as to make efficient use of extreme ultraviolet radiation from a large area radiation source (e.g., D{sub source} {approx_equal} 0.5 mm). The camera comprises four aspheric mirrors optically arranged on a common axis of symmetry. The camera includes an aperture stop that is accessible through a plurality of partial aperture stops to synthesize the theoretical aperture stop. Radiation from a mask is focused to form a reduced image on a wafer, relative to the mask, by reflection from the four aspheric mirrors. 11 figs.

Optimizing Intratheater Military Airlift in Iraq and Afghanistan

DTIC Science & Technology

2013-01-01

2013 Page 37 Data lenr number of stops on route r aðr ; sÞ airfield at stop number s on route r, where 1# s # lenr carryaiaj cr amount of cargo c on...comes after, and within maxloadhops of, stop s on route r: 1# s , s## lenr , s#2 s #maxloadhops Variables SELECTr integer number of times airplane...so , lenr ; c (4) X r; s#: 1, s## lenr ; aðr; s#Þ5aj SELECTr # landingaj "aj 2 A (5) The objective function (1) calculates the priority-weighted value

Buffer thermal energy storage for a solar thermal powered 1-MW sub e electrical plant

NASA Astrophysics Data System (ADS)

Polzien, R. E.

The application of a latent heat thermal energy buffer storage (TEBS) subsystem to the small community solar thermal power experiment (SCSE) is discussed. The SCSE is a 1-MW sub e solar thermal electric plant consisting of multiple paraboloidal concentrators with an organic Rankine cycle power conversion unit mounted at the focus of each concentrator. Objective of the TEBS is to minimize plant shutdowns during intermittent cloud coverage thereby improving life expectancy of major subsystems. An SCSE plant performance model is used with time varying insolation to show that 70 to 80 percent of the potential engine shutdowns may be averted with the TEBS system. Parametric variation of engine life dependency on start/stop cycles shows the potential for a 4 percent reduction in levelized bus bar energy cost using TEBS.

Split delivery vehicle routing problem with time windows: a case study

NASA Astrophysics Data System (ADS)

Latiffianti, E.; Siswanto, N.; Firmandani, R. A.

2018-04-01

This paper aims to implement an extension of VRP so called split delivery vehicle routing problem (SDVRP) with time windows in a case study involving pickups and deliveries of workers from several points of origin and several destinations. Each origin represents a bus stop and the destination represents either site or office location. An integer linear programming of the SDVRP problem is presented. The solution was generated using three stages of defining the starting points, assigning busses, and solving the SDVRP with time windows using an exact method. Although the overall computational time was relatively lengthy, the results indicated that the produced solution was better than the existing routing and scheduling that the firm used. The produced solution was also capable of reducing fuel cost by 9% that was obtained from shorter total distance travelled by the shuttle buses.

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.

Optimization and conceptual design of demonstration military and civilian mobile satellites using existing buses

NASA Astrophysics Data System (ADS)

Sultan, N.; Payne, W. F.; Carter, D. R.; Jeffrey, G. I.

The Canadian Mobile Satellite (MSAT) program had the objective to demonstrate the feasibility of reliable communications, via a geosynchronous satellite, to a variety of civilian and military users, operating in different frequency bands. The military system would provide, with various degrees of protection against jamming, a variety of military communication services. The civilian mobile satellite system was intended to provide public, mobile radio service (MRS), mobile telephone service (MTS), and data service (DS) to mobile and transportable terminals operating in the 821-825 MHz and 866-870 MHz bands. Service is to be provided for remote data collection platforms. The present investigation is concerned with the feasibility for a military or combined mission using an existing civilian bus, at least for the demonstration phase. It is found that such a use of a civilian bus is indeed feasible.

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.

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...

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.

Optimal Design of a Traveling-Wave Kinetic Inductance Amplifier Operated in Three-Wave Mixing Mode

NASA Astrophysics Data System (ADS)

Erickson, Robert; Bal, Mustafa; Ku, Ksiang-Sheng; Wu, Xian; Pappas, David

In the presence of a DC bias, an injected pump, of frequency fP, and a signal, of frequency fS, undergo parametric three-way mixing (3WM) within a traveling-wave kinetic inductance (KIT) amplifier, producing an idler product of frequency fI =fP -fS . Periodic frequency stops are engineered into the coplanar waveguide of the device to enhance signal amplification. With fP placed just above the first frequency stop gap, 3WM broadband signal gain is achieved with maximum gain at fS =fP / 2 . Within a theory of the dispersion of traveling waves in the presence of these engineered loadings, which accounts for this broadband signal gain, we show how an optimal frequency-stop design may be constructed to achieve maximum signal amplification. The optimization approach we describe can be applied to the design of other nonlinear traveling-wave parametric amplifiers. This work was supported by the Army Research Office and the Laboratory for Physical Sciences under EAO221146, EAO241777, and the NIST Quantum Initiative. RPE acknowledges Grant 60NANB14D024 from the US Department of Commerce, NIST.

Voltage stability index based optimal placement of static VAR compensator and sizing using Cuckoo search algorithm

NASA Astrophysics Data System (ADS)

Venkateswara Rao, B.; Kumar, G. V. Nagesh; Chowdary, D. Deepak; Bharathi, M. Aruna; Patra, Stutee

2017-07-01

This paper furnish the new Metaheuristic algorithm called Cuckoo Search Algorithm (CSA) for solving optimal power flow (OPF) problem with minimization of real power generation cost. The CSA is found to be the most efficient algorithm for solving single objective optimal power flow problems. The CSA performance is tested on IEEE 57 bus test system with real power generation cost minimization as objective function. Static VAR Compensator (SVC) is one of the best shunt connected device in the Flexible Alternating Current Transmission System (FACTS) family. It has capable of controlling the voltage magnitudes of buses by injecting the reactive power to system. In this paper SVC is integrated in CSA based Optimal Power Flow to optimize the real power generation cost. SVC is used to improve the voltage profile of the system. CSA gives better results as compared to genetic algorithm (GA) in both without and with SVC conditions.

Implementing a quantum cloning machine in separate cavities via the optical coherent pulse as a quantum communication bus

NASA Astrophysics Data System (ADS)

Zhu, Meng-Zheng; Ye, Liu

2015-04-01

An efficient scheme is proposed to implement a quantum cloning machine in separate cavities based on a hybrid interaction between electron-spin systems placed in the cavities and an optical coherent pulse. The coefficient of the output state for the present cloning machine is just the direct product of two trigonometric functions, which ensures that different types of quantum cloning machine can be achieved readily in the same framework by appropriately adjusting the rotated angles. The present scheme can implement optimal one-to-two symmetric (asymmetric) universal quantum cloning, optimal symmetric (asymmetric) phase-covariant cloning, optimal symmetric (asymmetric) real-state cloning, optimal one-to-three symmetric economical real-state cloning, and optimal symmetric cloning of qubits given by an arbitrary axisymmetric distribution. In addition, photon loss of the qubus beams during the transmission and decoherence effects caused by such a photon loss are investigated.

Design of static synchronous series compensator based damping controller employing invasive weed optimization algorithm.

PubMed

Ahmed, Ashik; Al-Amin, Rasheduzzaman; Amin, Ruhul

2014-01-01

This paper proposes designing of Static Synchronous Series Compensator (SSSC) based damping controller to enhance the stability of a Single Machine Infinite Bus (SMIB) system by means of Invasive Weed Optimization (IWO) technique. Conventional PI controller is used as the SSSC damping controller which takes rotor speed deviation as the input. The damping controller parameters are tuned based on time integral of absolute error based cost function using IWO. Performance of IWO based controller is compared to that of Particle Swarm Optimization (PSO) based controller. Time domain based simulation results are presented and performance of the controllers under different loading conditions and fault scenarios is studied in order to illustrate the effectiveness of the IWO based design approach.

MBus: An Ultra-Low Power Interconnect Bus for Next Generation Nanopower Systems

PubMed Central

Pannuto, Pat; Lee, Yoonmyung; Kuo, Ye-Sheng; Foo, ZhiYoong; Kempke, Benjamin; Kim, Gyouho; Dreslinski, Ronald G.; Blaauw, David; Dutta, Prabal

2015-01-01

As we show in this paper, I/O has become the limiting factor in scaling down size and power toward the goal of invisible computing. Achieving this goal will require composing optimized and specialized—yet reusable—components with an interconnect that permits tiny, ultra-low power systems. In contrast to today’s interconnects which are limited by power-hungry pull-ups or high-overhead chip-select lines, our approach provides a superset of common bus features but at lower power, with fixed area and pin count, using fully synthesizable logic, and with surprisingly low protocol overhead. We present MBus, a new 4-pin, 22.6 pJ/bit/chip chip-to-chip interconnect made of two “shoot-through” rings. MBus facilitates ultra-low power system operation by implementing automatic power-gating of each chip in the system, easing the integration of active, inactive, and activating circuits on a single die. In addition, we introduce a new bus primitive: power oblivious communication, which guarantees message reception regardless of the recipient’s power state when a message is sent. This disentangles power management from communication, greatly simplifying the creation of viable, modular, and heterogeneous systems that operate on the order of nanowatts. To evaluate the viability, power, performance, overhead, and scalability of our design, we build both hardware and software implementations of MBus and show its seamless operation across two FPGAs and twelve custom chips from three different semiconductor processes. A three-chip, 2.2 mm3 MBus system draws 8 nW of total system standby power and uses only 22.6 pJ/bit/chip for communication. This is the lowest power for any system bus with MBus’s feature set. PMID:26855555

MBus: An Ultra-Low Power Interconnect Bus for Next Generation Nanopower Systems.

PubMed

Pannuto, Pat; Lee, Yoonmyung; Kuo, Ye-Sheng; Foo, ZhiYoong; Kempke, Benjamin; Kim, Gyouho; Dreslinski, Ronald G; Blaauw, David; Dutta, Prabal

2015-06-01

As we show in this paper, I/O has become the limiting factor in scaling down size and power toward the goal of invisible computing. Achieving this goal will require composing optimized and specialized-yet reusable-components with an interconnect that permits tiny, ultra-low power systems. In contrast to today's interconnects which are limited by power-hungry pull-ups or high-overhead chip-select lines, our approach provides a superset of common bus features but at lower power, with fixed area and pin count, using fully synthesizable logic, and with surprisingly low protocol overhead. We present MBus , a new 4-pin, 22.6 pJ/bit/chip chip-to-chip interconnect made of two "shoot-through" rings. MBus facilitates ultra-low power system operation by implementing automatic power-gating of each chip in the system, easing the integration of active, inactive, and activating circuits on a single die. In addition, we introduce a new bus primitive: power oblivious communication, which guarantees message reception regardless of the recipient's power state when a message is sent. This disentangles power management from communication, greatly simplifying the creation of viable, modular, and heterogeneous systems that operate on the order of nanowatts. To evaluate the viability, power, performance, overhead, and scalability of our design, we build both hardware and software implementations of MBus and show its seamless operation across two FPGAs and twelve custom chips from three different semiconductor processes. A three-chip, 2.2 mm 3 MBus system draws 8 nW of total system standby power and uses only 22.6 pJ/bit/chip for communication. This is the lowest power for any system bus with MBus's feature set.

Analysis and design of a high power, digitally-controlled spacecraft power system

NASA Technical Reports Server (NTRS)

Lee, F. C.; Cho, B. H.

1990-01-01

The progress to date on the analysis and design of a high power, digitally controlled spacecraft power system is described. Several battery discharger topologies were compared for use in the space platform application. Updated information has been provided on the battery voltage specification. Initially it was thought to be in the 30 to 40 V range. It is now specified to be 53 V to 84 V. This eliminated the tapped-boost and the current-fed auto-transformer converters from consideration. After consultations with NASA, it was decided to trade-off the following topologies: (1) boost converter; (2) multi-module, multi-phase boost converter; and (3) voltage-fed push-pull with auto-transformer. A non-linear design optimization software tool was employed to facilitate an objective comparison. Non-linear design optimization insures that the best design of each topology is compared. The results indicate that a four-module, boost converter with each module operating 90 degrees out of phase is the optimum converter for the space platform. Large-signal and small-signal models were generated for the shunt, charger, discharger, battery, and the mode controller. The models were first tested individually according to the space platform power system specifications supplied by NASA. The effect of battery voltage imbalance on parallel dischargers was investigated with respect to dc and small-signal responses. Similarly, the effects of paralleling dischargers and chargers were also investigated. A solar array and shunt model was included in these simulations. A model for the bus mode controller (power control unit) was also developed to interface the Orbital replacement Unit (ORU) model to the platform power system. Small signal models were used to generate the bus impedance plots in the various operating modes. The large signal models were integrated into a system model, and time domain simulations were performed to verify bus regulation during mode transitions. Some changes have subsequently been incorporated into the models. The changes include the use of a four module boost discharger, and a new model for the mode controller, which includes the effects of saturation. The new simulations for the boost discharger show the improvement in bus ripple that can be achieved by phase-shifted operation of each of the boost modules.

Dissociable brain mechanisms underlying the conscious and unconscious control of behavior.

PubMed

van Gaal, Simon; Lamme, Victor A F; Fahrenfort, Johannes J; Ridderinkhof, K Richard

2011-01-01

Cognitive control allows humans to overrule and inhibit habitual responses to optimize performance in challenging situations. Contradicting traditional views, recent studies suggest that cognitive control processes can be initiated unconsciously. To further capture the relation between consciousness and cognitive control, we studied the dynamics of inhibitory control processes when triggered consciously versus unconsciously in a modified version of the stop task. Attempts to inhibit an imminent response were often successful after unmasked (visible) stop signals. Masked (invisible) stop signals rarely succeeded in instigating overt inhibition but did trigger slowing down of response times. Masked stop signals elicited a sequence of distinct ERP components that were also observed on unmasked stop signals. The N2 component correlated with the efficiency of inhibitory control when elicited by unmasked stop signals and with the magnitude of slowdown when elicited by masked stop signals. Thus, the N2 likely reflects the initiation of inhibitory control, irrespective of conscious awareness. The P3 component was much reduced in amplitude and duration on masked versus unmasked stop trials. These patterns of differences and similarities between conscious and unconscious cognitive control processes are discussed in a framework that differentiates between feedforward and feedback connections in yielding conscious experience.

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

Dc microgrid stabilization through fuzzy control of interleaved, heterogeneous storage elements

NASA Astrophysics Data System (ADS)

Smith, Robert David

As microgrid power systems gain prevalence and renewable energy comprises greater and greater portions of distributed generation, energy storage becomes important to offset the higher variance of renewable energy sources and maximize their usefulness. One of the emerging techniques is to utilize a combination of lead-acid batteries and ultracapacitors to provide both short and long-term stabilization to microgrid systems. The different energy and power characteristics of batteries and ultracapacitors imply that they ought to be utilized in different ways. Traditional linear controls can use these energy storage systems to stabilize a power grid, but cannot effect more complex interactions. This research explores a fuzzy logic approach to microgrid stabilization. The ability of a fuzzy logic controller to regulate a dc bus in the presence of source and load fluctuations, in a manner comparable to traditional linear control systems, is explored and demonstrated. Furthermore, the expanded capabilities (such as storage balancing, self-protection, and battery optimization) of a fuzzy logic system over a traditional linear control system are shown. System simulation results are presented and validated through hardware-based experiments. These experiments confirm the capabilities of the fuzzy logic control system to regulate bus voltage, balance storage elements, optimize battery usage, and effect self-protection.

Optimal placement of unified power flow controllers to improve dynamic voltage stability using power system variable based voltage stability indices.

PubMed

Albatsh, Fadi M; Ahmad, Shameem; Mekhilef, Saad; Mokhlis, Hazlie; Hassan, M A

2015-01-01

This study examines a new approach to selecting the locations of unified power flow controllers (UPFCs) in power system networks based on a dynamic analysis of voltage stability. Power system voltage stability indices (VSIs) including the line stability index (LQP), the voltage collapse proximity indicator (VCPI), and the line stability index (Lmn) are employed to identify the most suitable locations in the system for UPFCs. In this study, the locations of the UPFCs are identified by dynamically varying the loads across all of the load buses to represent actual power system conditions. Simulations were conducted in a power system computer-aided design (PSCAD) software using the IEEE 14-bus and 39- bus benchmark power system models. The simulation results demonstrate the effectiveness of the proposed method. When the UPFCs are placed in the locations obtained with the new approach, the voltage stability improves. A comparison of the steady-state VSIs resulting from the UPFCs placed in the locations obtained with the new approach and with particle swarm optimization (PSO) and differential evolution (DE), which are static methods, is presented. In all cases, the UPFC locations given by the proposed approach result in better voltage stability than those obtained with the other approaches.

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.

Optimal Placement of Unified Power Flow Controllers to Improve Dynamic Voltage Stability Using Power System Variable Based Voltage Stability Indices

PubMed Central

Albatsh, Fadi M.; Ahmad, Shameem; Mekhilef, Saad; Mokhlis, Hazlie; Hassan, M. A.

2015-01-01

This study examines a new approach to selecting the locations of unified power flow controllers (UPFCs) in power system networks based on a dynamic analysis of voltage stability. Power system voltage stability indices (VSIs) including the line stability index (LQP), the voltage collapse proximity indicator (VCPI), and the line stability index (Lmn) are employed to identify the most suitable locations in the system for UPFCs. In this study, the locations of the UPFCs are identified by dynamically varying the loads across all of the load buses to represent actual power system conditions. Simulations were conducted in a power system computer-aided design (PSCAD) software using the IEEE 14-bus and 39- bus benchmark power system models. The simulation results demonstrate the effectiveness of the proposed method. When the UPFCs are placed in the locations obtained with the new approach, the voltage stability improves. A comparison of the steady-state VSIs resulting from the UPFCs placed in the locations obtained with the new approach and with particle swarm optimization (PSO) and differential evolution (DE), which are static methods, is presented. In all cases, the UPFC locations given by the proposed approach result in better voltage stability than those obtained with the other approaches. PMID:25874560

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.

Optimization of Artificial Neural Network using Evolutionary Programming for Prediction of Cascading Collapse Occurrence due to the Hidden Failure Effect

NASA Astrophysics Data System (ADS)

Idris, N. H.; Salim, N. A.; Othman, M. M.; Yasin, Z. M.

2018-03-01

This paper presents the Evolutionary Programming (EP) which proposed to optimize the training parameters for Artificial Neural Network (ANN) in predicting cascading collapse occurrence due to the effect of protection system hidden failure. The data has been collected from the probability of hidden failure model simulation from the historical data. The training parameters of multilayer-feedforward with backpropagation has been optimized with objective function to minimize the Mean Square Error (MSE). The optimal training parameters consists of the momentum rate, learning rate and number of neurons in first hidden layer and second hidden layer is selected in EP-ANN. The IEEE 14 bus system has been tested as a case study to validate the propose technique. The results show the reliable prediction of performance validated through MSE and Correlation Coefficient (R).

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.

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".

Ringfield lithographic camera

DOEpatents

Sweatt, William C.

1998-01-01

A projection lithography camera is presented with a wide ringfield optimized so as to make efficient use of extreme ultraviolet radiation from a large area radiation source (e.g., D.sub.source .apprxeq.0.5 mm). The camera comprises four aspheric mirrors optically arranged on a common axis of symmetry with an increased etendue for the camera system. The camera includes an aperture stop that is accessible through a plurality of partial aperture stops to synthesize the theoretical aperture stop. Radiation from a mask is focused to form a reduced image on a wafer, relative to the mask, by reflection from the four aspheric mirrors.

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.

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 (

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...

A Clustering Based Approach for Observability and Controllability Analysis for Optimal Placement of PMU

NASA Astrophysics Data System (ADS)

Murthy, Ch; MIEEE; Mohanta, D. K.; SMIEE; Meher, Mahendra

2017-08-01

Continuous monitoring and control of the power system is essential for its healthy operation. This can be achieved by making the system observable as well as controllable. Many efforts have been made by several researchers to make the system observable by placing the Phasor Measurement Units (PMUs) at the optimal locations. But so far the idea of controllability with PMUs is not considered. This paper contributes how to check whether the system is controllable or not, if not then how make it controllable using a clustering approach. IEEE 14 bus system is considered to illustrate the concept of controllability.

An application of different dioids in public key cryptography

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

Durcheva, Mariana I., E-mail: mdurcheva66@gmail.com

2014-11-18

Dioids provide a natural framework for analyzing a broad class of discrete event dynamical systems such as the design and analysis of bus and railway timetables, scheduling of high-throughput industrial processes, solution of combinatorial optimization problems, the analysis and improvement of flow systems in communication networks. They have appeared in several branches of mathematics such as functional analysis, optimization, stochastic systems and dynamic programming, tropical geometry, fuzzy logic. In this paper we show how to involve dioids in public key cryptography. The main goal is to create key – exchange protocols based on dioids. Additionally the digital signature scheme ismore » presented.« less

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

Multi-procedure management in an eyeglasses-related open globe injury

PubMed Central

Skopiński, Piotr; Langwińska-Wośko, Ewa; Korwin, Magdalena; Kołodziejczyk, Wojciech; Ambroziak, Anna Maria

2014-01-01

We present a case of successful multi-procedure management of a patient with an open globe injury. A 47-year-old man sustained an injury to his left eye caused by glass fragments of his own spectacles shattered while he was protecting an unknown woman from physical assault at a bus stop. Over a span of 65 months the patient underwent multiple procedures including primary wound repair, penetrating keratoplasty combined with extracapsular cataract extraction, neodymium: YAG laser capsulotomy, and laser-assisted subepithelial keratectomy (LASEK), and had a successfully treated episode of corneal graft rejection. This sequence of treatment substantially improved his left eye vision from hand movements at the time of admission to 0.9–0.5 × 90 at the last follow-up nearly 10 years after the trauma. Proper initial surgical management of an open globe injury can create the possibility for virtually complete vision restoration. PMID:24729818

Optimal placement of FACTS devices using optimization techniques: A review

NASA Astrophysics Data System (ADS)

Gaur, Dipesh; Mathew, Lini

2018-03-01

Modern power system is dealt with overloading problem especially transmission network which works on their maximum limit. Today’s power system network tends to become unstable and prone to collapse due to disturbances. Flexible AC Transmission system (FACTS) provides solution to problems like line overloading, voltage stability, losses, power flow etc. FACTS can play important role in improving static and dynamic performance of power system. FACTS devices need high initial investment. Therefore, FACTS location, type and their rating are vital and should be optimized to place in the network for maximum benefit. In this paper, different optimization methods like Particle Swarm Optimization (PSO), Genetic Algorithm (GA) etc. are discussed and compared for optimal location, type and rating of devices. FACTS devices such as Thyristor Controlled Series Compensator (TCSC), Static Var Compensator (SVC) and Static Synchronous Compensator (STATCOM) are considered here. Mentioned FACTS controllers effects on different IEEE bus network parameters like generation cost, active power loss, voltage stability etc. have been analyzed and compared among the devices.

Stopping Criteria for Log-Domain Diffeomorphic Demons Registration: An Experimental Survey for Radiotherapy Application.

PubMed

Peroni, M; Golland, P; Sharp, G C; Baroni, G

2016-02-01

A crucial issue in deformable image registration is achieving a robust registration algorithm at a reasonable computational cost. Given the iterative nature of the optimization procedure an algorithm must automatically detect convergence, and stop the iterative process when most appropriate. This paper ranks the performances of three stopping criteria and six stopping value computation strategies for a Log-Domain Demons Deformable registration method simulating both a coarse and a fine registration. The analyzed stopping criteria are: (a) velocity field update magnitude, (b) mean squared error, and (c) harmonic energy. Each stoping condition is formulated so that the user defines a threshold ∊, which quantifies the residual error that is acceptable for the particular problem and calculation strategy. In this work, we did not aim at assigning a value to e, but to give insights in how to evaluate and to set the threshold on a given exit strategy in a very popular registration scheme. Experiments on phantom and patient data demonstrate that comparing the optimization metric minimum over the most recent three iterations with the minimum over the fourth to sixth most recent iterations can be an appropriate algorithm stopping strategy. The harmonic energy was found to provide best trade-off between robustness and speed of convergence for the analyzed registration method at coarse registration, but was outperformed by mean squared error when all the original pixel information is used. This suggests the need of developing mathematically sound new convergence criteria in which both image and vector field information could be used to detect the actual convergence, which could be especially useful when considering multi-resolution registrations. Further work should be also dedicated to study same strategies performances in other deformable registration methods and body districts. © The Author(s) 2014.

Ranking of stopping criteria for log domain diffeomorphic demons application in clinical radiation therapy.

PubMed

Peroni, M; Golland, P; Sharp, G C; Baroni, G

2011-01-01

Deformable Image Registration is a complex optimization algorithm with the goal of modeling a non-rigid transformation between two images. A crucial issue in this field is guaranteeing the user a robust but computationally reasonable algorithm. We rank the performances of four stopping criteria and six stopping value computation strategies for a log domain deformable registration. The stopping criteria we test are: (a) velocity field update magnitude, (b) vector field Jacobian, (c) mean squared error, and (d) harmonic energy. Experiments demonstrate that comparing the metric value over the last three iterations with the metric minimum of between four and six previous iterations is a robust and appropriate strategy. The harmonic energy and vector field update magnitude metrics give the best results in terms of robustness and speed of convergence.

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

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...

Network Extender for MIL-STD-1553 Bus

NASA Technical Reports Server (NTRS)

Marcus, Julius; Hanson, T. David

2003-01-01

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

Design and fabrication of a full-scale actively controlled satellite appendage simulator unit

NASA Astrophysics Data System (ADS)

Jacobs, Jack H.; Quenon, Dan; Hadden, Steve; Self, Rick

1999-07-01

Modern satellites require the ability to slew and settle quickly in order to acquire or transmit data efficiently. Solar arrays and communication antennas cause low frequency disturbances to the satellite bus during these maneuvers causing undesirable induced vibration of the payload. The ability to develop and experimentally demonstrate attitude control laws which compensate for these flexible body disturbances is of prime importance to modern day satellite manufacturers. Honeywell has designed and fabricated an actively controlled Appendage Simulator Unit (ASU) which can physically induce the modal characteristics of satellite appendages on to a ground based satellite test bed installed on an air bearing. The ASU consists of two orthogonal fulcrum beams weighting over 800 pounds each utilizing two electrodynamic shakers to induce active torques onto the bus. The ASU is programmed with the state space characteristics of the desired appendage and responds in real time to the bus motion to generate realistic disturbances back onto the satellite. Two LVDT's are used on each fulcrum beam to close the loop and insure the system responds in real time the same way a real solar array would on-orbit. Each axis is independently programmable in order to simulate various orientations or modal contributions from an appendage. The design process for the ASU involved the optimization of sensors, actuators, control authority, weight, power and functionality. The smart structure system design process and experimental results are described in detail.

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...

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.

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...

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.

Optimal Battery Sizing in Photovoltaic Based Distributed Generation Using Enhanced Opposition-Based Firefly Algorithm for Voltage Rise Mitigation

PubMed Central

Wong, Ling Ai; Shareef, Hussain; Mohamed, Azah; Ibrahim, Ahmad Asrul

2014-01-01

This paper presents the application of enhanced opposition-based firefly algorithm in obtaining the optimal battery energy storage systems (BESS) sizing in photovoltaic generation integrated radial distribution network in order to mitigate the voltage rise problem. Initially, the performance of the original firefly algorithm is enhanced by utilizing the opposition-based learning and introducing inertia weight. After evaluating the performance of the enhanced opposition-based firefly algorithm (EOFA) with fifteen benchmark functions, it is then adopted to determine the optimal size for BESS. Two optimization processes are conducted where the first optimization aims to obtain the optimal battery output power on hourly basis and the second optimization aims to obtain the optimal BESS capacity by considering the state of charge constraint of BESS. The effectiveness of the proposed method is validated by applying the algorithm to the 69-bus distribution system and by comparing the performance of EOFA with conventional firefly algorithm and gravitational search algorithm. Results show that EOFA has the best performance comparatively in terms of mitigating the voltage rise problem. PMID:25054184

Optimal battery sizing in photovoltaic based distributed generation using enhanced opposition-based firefly algorithm for voltage rise mitigation.

PubMed

Wong, Ling Ai; Shareef, Hussain; Mohamed, Azah; Ibrahim, Ahmad Asrul

2014-01-01

This paper presents the application of enhanced opposition-based firefly algorithm in obtaining the optimal battery energy storage systems (BESS) sizing in photovoltaic generation integrated radial distribution network in order to mitigate the voltage rise problem. Initially, the performance of the original firefly algorithm is enhanced by utilizing the opposition-based learning and introducing inertia weight. After evaluating the performance of the enhanced opposition-based firefly algorithm (EOFA) with fifteen benchmark functions, it is then adopted to determine the optimal size for BESS. Two optimization processes are conducted where the first optimization aims to obtain the optimal battery output power on hourly basis and the second optimization aims to obtain the optimal BESS capacity by considering the state of charge constraint of BESS. The effectiveness of the proposed method is validated by applying the algorithm to the 69-bus distribution system and by comparing the performance of EOFA with conventional firefly algorithm and gravitational search algorithm. Results show that EOFA has the best performance comparatively in terms of mitigating the voltage rise problem.

Parallel Hybrid Vehicle Optimal Storage System

NASA Technical Reports Server (NTRS)

Bloomfield, Aaron P.

2009-01-01

A paper reports the results of a Hybrid Diesel Vehicle Project focused on a parallel hybrid configuration suitable for diesel-powered, medium-sized, commercial vehicles commonly used for parcel delivery and shuttle buses, as the missions of these types of vehicles require frequent stops. During these stops, electric hybridization can effectively recover the vehicle's kinetic energy during the deceleration, store it onboard, and then use that energy to assist in the subsequent acceleration.

Long-haul truck drivers want healthful meal options at truck-stop restaurants.

PubMed

Whitfield Jacobson, Pamela J; Prawitz, Aimee D; Lukaszuk, Judith M

2007-12-01

Long-haul truckers are confined, by parking regulations and other constraints, to dining at truck-stop restaurants. Objectives were to (a) compare truckers' anthropometrics with recommended guidelines; and (b) assess eating/exercise habits, importance of healthful food choices, and attitudes about restaurants' provision of healthful options. Hypotheses were: (a) overweight/obese drivers will place less importance on healthful food choices than will drivers of optimal weight; (b) importance of healthful food choices and attitudes about their provision will be positively correlated. Questionnaires included Food Choices Index, Nutrition Attitude Survey, and demographic information; bioelectrical impedance assessed weight, body fat, and body mass index. Subjects (n=92) were truckers at a Midwestern truck-stop restaurant; 79 were overweight, 52 were obese. Mean rating of importance of healthful choices was above average. There was no difference in importance of healthful food choices for overweight/obese and optimal weight drivers, t(89)=-1.312; P=0.19. Drivers placing more importance on healthful food choices had more positive attitudes about restaurants' provision of such options, r(90)=0.74, P<0.001. Overall, drivers indicated they would choose healthful foods if available and appetizing. Registered dietitian-directed wellness programs that include education, support, and cooperation of truck-stop restaurants are critical to reduce obesity and risk of disease in this population.

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.

Case study of a healthy eating intervention for Swedish lorry drivers.

PubMed

Gill, Peter E; Wijk, Katarina

2004-06-01

Professional drivers, i.e. lorry, truck, bus and taxi drivers, have been identified as a particular health risk group. An intervention to study the efficacy of a series of educational programmes, involving improved nutritional balance in meals served, food preparation routines and carrying out personal health profiles on staff, was implemented at a Swedish truck stop in order to target this specific hard-to-reach risk group. Professional drivers were targeted through an information campaign, healthier 'Today's Special' choices and by using staff as proxy health promoters. A campaign emblem on the menu notice board indicated healthier food choice menu items. Drivers choosing healthier alternatives were given lottery tokens. The intervention was evaluated through nutritional analyses, field observations, questionnaires and interviews. Positive staff-level outcomes included increased nutritional awareness, personal health empowerment and, most crucially, overwhelming staff support for a health-promoting role. Nutritional analysis of pre- and post-intervention 'Today's Specials' showed a better balance of fat, calories, carbohydrates and protein (per 100 g) content in the dishes tested. At management level there were economic benefits in terms of time savings and reduced use of cooking fat in food preparation. Drivers tended to choose healthier alternatives and there was increased awareness of the healthier alternatives on offer. The case study showed that using truck stop staff as proxy health promoters offers a viable intervention strategy.

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.

A Pause-then-Cancel model of stopping: evidence from basal ganglia neurophysiology

PubMed Central

Berke, Joshua D.

2017-01-01

Many studies have implicated the basal ganglia in the suppression of action impulses (‘stopping’). Here, we discuss recent neurophysiological evidence that distinct hypothesized processes involved in action preparation and cancellation can be mapped onto distinct basal ganglia cell types and pathways. We examine how movement-related activity in the striatum is related to a ‘Go’ process and how going may be modulated by brief epochs of beta oscillations. We then describe how, rather than a unitary ‘Stop’ process, there appear to be separate, complementary ‘Pause’ and ‘Cancel’ mechanisms. We discuss the implications of these stopping subprocesses for the interpretation of the stop-signal reaction time—in particular, some activity that seems too slow to causally contribute to stopping when assuming a single Stop processes may actually be fast enough under a Pause-then-Cancel model. Finally, we suggest that combining complementary neural mechanisms that emphasize speed or accuracy respectively may serve more generally to optimize speed–accuracy trade-offs. This article is part of the themed issue ‘Movement suppression: brain mechanisms for stopping and stillness’. PMID:28242736

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.

Optimal surveillance strategy for invasive species management when surveys stop after detection.

PubMed

Guillera-Arroita, Gurutzeta; Hauser, Cindy E; McCarthy, Michael A

2014-05-01

Invasive species are a cause for concern in natural and economic systems and require both monitoring and management. There is a trade-off between the amount of resources spent on surveying for the species and conducting early management of occupied sites, and the resources that are ultimately spent in delayed management at sites where the species was present but undetected. Previous work addressed this optimal resource allocation problem assuming that surveys continue despite detection until the initially planned survey effort is consumed. However, a more realistic scenario is often that surveys stop after detection (i.e., follow a "removal" sampling design) and then management begins. Such an approach will indicate a different optimal survey design and can be expected to be more efficient. We analyze this case and compare the expected efficiency of invasive species management programs under both survey methods. We also evaluate the impact of mis-specifying the type of sampling approach during the program design phase. We derive analytical expressions that optimize resource allocation between monitoring and management in surveillance programs when surveys stop after detection. We do this under a scenario of unconstrained resources and scenarios where survey budget is constrained. The efficiency of surveillance programs is greater if a "removal survey" design is used, with larger gains obtained when savings from early detection are high, occupancy is high, and survey costs are not much lower than early management costs at a site. Designing a surveillance program disregarding that surveys stop after detection can result in an efficiency loss. Our results help guide the design of future surveillance programs for invasive species. Addressing program design within a decision-theoretic framework can lead to a better use of available resources. We show how species prevalence, its detectability, and the benefits derived from early detection can be considered.

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...

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 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.

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.

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.

Children at risk: A comparison of child pedestrian traffic collisions in Santiago, Chile, and Seoul, South Korea.

PubMed

Blazquez, Carola; Lee, Jae Seung; Zegras, Christopher

2016-01-01

We examine and compare pedestrian-vehicle collisions and injury outcomes involving school-age children between 5 and 18 years of age in the capital cities of Santiago, Chile, and Seoul, South Korea. We conduct descriptive analysis of the child pedestrian-vehicle collision (P-VC) data (904 collisions for Santiago and 3,505 for Seoul) reported by the police between 2010 and 2011. We also statistically analyze factors associated with child P-VCs, by both incident severity and age group, using 3 regression models: negative binomial, probit, and spatial lag models. Descriptive statistics suggest that child pedestrians in Seoul have a higher risk of being involved in traffic crashes than their counterparts in Santiago. However, in Seoul a greater proportion of children are unharmed as a result of these incidents, whereas more child pedestrians are killed in Santiago. Younger children in Seoul suffer more injuries from P-VCs than in Santiago. The majority of P-VCs in both cities tend to occur in the afternoon and evening, at intersections in Santiago and at midblock locations in Seoul. Our model results suggest that the resident population of children is positively associated with P-VCs in both cities, and school concentrations apparently increase P-VC risk among older children in Santiago. Bus stops are associated with higher P-VCs in Seoul, and subway stations relate to higher P-VCs among older children in Santiago. Zone-level land use mix was negatively related to child P-VCs in Seoul but not in Santiago. Arterial roads are associated with fewer P-VCs, especially for younger children in both cities. A share of collector roads is associated with increased P-VCs in Seoul but fewer P-VCs in Santiago. Hilliness is related to fewer P-VCs in both cities. Differences in these model results for Santiago and Seoul warrant additional analysis, as do the differences in results across model type (negative binomial versus spatial lag models). To reduce child P-VCs, this study suggests the need to assess subway station and bus stop area conditions in Santiago and Seoul, respectively; areas with high density of schools in Santiago; areas with greater concentrations of children in both cities; and collector roads in Seoul.

Hamiltonian methods of modeling and control of AC microgrids with spinning machines and inverters

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

Matthews, Ronald C.; Weaver, Wayne W.; Robinett, Rush D.

This study presents a novel approach to the modeling and control of AC microgrids that contain spinning machines, power electronic inverters and energy storage devices. The inverters in the system can adjust their frequencies and power angles very quickly, so the modeling focuses on establishing a common reference frequency and angle in the microgrid based on the spinning machines. From this dynamic model, nonlinear Hamiltonian surface shaping and power flow control method is applied and shown to stabilize. From this approach the energy flow in the system is used to show the energy storage device requirements and limitations for themore » system. This paper first describes the model for a single bus AC microgrid with a Hamiltonian control, then extends this model and control to a more general class of multiple bus AC microgrids. Finally, simulation results demonstrate the efficacy of the approach in stabilizing and optimization of the microgrid.« less

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.

Hamiltonian methods of modeling and control of AC microgrids with spinning machines and inverters

DOE PAGES

Matthews, Ronald C.; Weaver, Wayne W.; Robinett, Rush D.; ...

2017-12-22

This study presents a novel approach to the modeling and control of AC microgrids that contain spinning machines, power electronic inverters and energy storage devices. The inverters in the system can adjust their frequencies and power angles very quickly, so the modeling focuses on establishing a common reference frequency and angle in the microgrid based on the spinning machines. From this dynamic model, nonlinear Hamiltonian surface shaping and power flow control method is applied and shown to stabilize. From this approach the energy flow in the system is used to show the energy storage device requirements and limitations for themore » system. This paper first describes the model for a single bus AC microgrid with a Hamiltonian control, then extends this model and control to a more general class of multiple bus AC microgrids. Finally, simulation results demonstrate the efficacy of the approach in stabilizing and optimization of the microgrid.« less

High-resolution quantization based on soliton self-frequency shift and spectral compression in a bi-directional comb-fiber architecture

NASA Astrophysics Data System (ADS)

Zhang, Xuyan; Zhang, Zhiyao; Wang, Shubing; Liang, Dong; Li, Heping; Liu, Yong

2018-03-01

We propose and demonstrate an approach that can achieve high-resolution quantization by employing soliton self-frequency shift and spectral compression. Our approach is based on a bi-directional comb-fiber architecture which is composed of a Sagnac-loop-based mirror and a comb-like combination of N sections of interleaved single-mode fibers and high nonlinear fibers. The Sagnac-loop-based mirror placed at the terminal of a bus line reflects the optical pulses back to the bus line to achieve additional N-stage spectral compression, thus single-stage soliton self-frequency shift (SSFS) and (2 N - 1)-stage spectral compression are realized in the bi-directional scheme. The fiber length in the architecture is numerically optimized, and the proposed quantization scheme is evaluated by both simulation and experiment in the case of N = 2. In the experiment, a quantization resolution of 6.2 bits is obtained, which is 1.2-bit higher than that of its uni-directional counterpart.

Chance-Constrained System of Systems Based Operation of Power Systems

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

Kargarian, Amin; Fu, Yong; Wu, Hongyu

In this paper, a chance-constrained system of systems (SoS) based decision-making approach is presented for stochastic scheduling of power systems encompassing active distribution grids. Based on the concept of SoS, the independent system operator (ISO) and distribution companies (DISCOs) are modeled as self-governing systems. These systems collaborate with each other to run the entire power system in a secure and economic manner. Each self-governing system accounts for its local reserve requirements and line flow constraints with respect to the uncertainties of load and renewable energy resources. A set of chance constraints are formulated to model the interactions between the ISOmore » and DISCOs. The proposed model is solved by using analytical target cascading (ATC) method, a distributed optimization algorithm in which only a limited amount of information is exchanged between collaborative ISO and DISCOs. In this paper, a 6-bus and a modified IEEE 118-bus power systems are studied to show the effectiveness of the proposed algorithm.« less

[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.

Multi-arm group sequential designs with a simultaneous stopping rule.

PubMed

Urach, S; Posch, M

2016-12-30

Multi-arm group sequential clinical trials are efficient designs to compare multiple treatments to a control. They allow one to test for treatment effects already in interim analyses and can have a lower average sample number than fixed sample designs. Their operating characteristics depend on the stopping rule: We consider simultaneous stopping, where the whole trial is stopped as soon as for any of the arms the null hypothesis of no treatment effect can be rejected, and separate stopping, where only recruitment to arms for which a significant treatment effect could be demonstrated is stopped, but the other arms are continued. For both stopping rules, the family-wise error rate can be controlled by the closed testing procedure applied to group sequential tests of intersection and elementary hypotheses. The group sequential boundaries for the separate stopping rule also control the family-wise error rate if the simultaneous stopping rule is applied. However, we show that for the simultaneous stopping rule, one can apply improved, less conservative stopping boundaries for local tests of elementary hypotheses. We derive corresponding improved Pocock and O'Brien type boundaries as well as optimized boundaries to maximize the power or average sample number and investigate the operating characteristics and small sample properties of the resulting designs. To control the power to reject at least one null hypothesis, the simultaneous stopping rule requires a lower average sample number than the separate stopping rule. This comes at the cost of a lower power to reject all null hypotheses. Some of this loss in power can be regained by applying the improved stopping boundaries for the simultaneous stopping rule. The procedures are illustrated with clinical trials in systemic sclerosis and narcolepsy. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

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.

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.

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

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...

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

An Investigation of DC-DC Converter Power Density Using Si and SiC MOSFETS

DTIC Science & Technology

2010-05-07

submarine or small surface combatant, volumetric constraints quickly become extremely prohibitive. Dedicating generators for high power loads takes...thermal compounds were applied to the MOSFET-heat sink interface. For the Si APT26F120B2, MG Chemicals TC-450ML thermal epoxy was used to connect the... submarines , bus converter modules must be made optimally power dense in order to decrease volumetric requirements of the modules for a rated throughput

Resolvent-Techniques for Multiple Exercise Problems

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

Christensen, Sören, E-mail: christensen@math.uni-kiel.de; Lempa, Jukka, E-mail: jukka.lempa@hioa.no

2015-02-15

We study optimal multiple stopping of strong Markov processes with random refraction periods. The refraction periods are assumed to be exponentially distributed with a common rate and independent of the underlying dynamics. Our main tool is using the resolvent operator. In the first part, we reduce infinite stopping problems to ordinary ones in a general strong Markov setting. This leads to explicit solutions for wide classes of such problems. Starting from this result, we analyze problems with finitely many exercise rights and explain solution methods for some classes of problems with underlying Lévy and diffusion processes, where the optimal characteristicsmore » of the problems can be identified more explicitly. We illustrate the main results with explicit examples.« less

Method and apparatus for high speed data acquisition and processing

DOEpatents

Ferron, J.R.

1997-02-11

A method and apparatus are disclosed for high speed digital data acquisition. The apparatus includes one or more multiplexers for receiving multiple channels of digital data at a low data rate and asserting a multiplexed data stream at a high data rate, and one or more FIFO memories for receiving data from the multiplexers and asserting the data to a real time processor. Preferably, the invention includes two multiplexers, two FIFO memories, and a 64-bit bus connecting the FIFO memories with the processor. Each multiplexer receives four channels of 14-bit digital data at a rate of up to 5 MHz per channel, and outputs a data stream to one of the FIFO memories at a rate of 20 MHz. The FIFO memories assert output data in parallel to the 64-bit bus, thus transferring 14-bit data values to the processor at a combined rate of 40 MHz. The real time processor is preferably a floating-point processor which processes 32-bit floating-point words. A set of mask bits is prestored in each 32-bit storage location of the processor memory into which a 14-bit data value is to be written. After data transfer from the FIFO memories, mask bits are concatenated with each stored 14-bit data value to define a valid 32-bit floating-point word. Preferably, a user can select any of several modes for starting and stopping direct memory transfers of data from the FIFO memories to memory within the real time processor, by setting the content of a control and status register. 15 figs.

Method and apparatus for high speed data acquisition and processing

DOEpatents

Ferron, John R.

1997-01-01

A method and apparatus for high speed digital data acquisition. The apparatus includes one or more multiplexers for receiving multiple channels of digital data at a low data rate and asserting a multiplexed data stream at a high data rate, and one or more FIFO memories for receiving data from the multiplexers and asserting the data to a real time processor. Preferably, the invention includes two multiplexers, two FIFO memories, and a 64-bit bus connecting the FIFO memories with the processor. Each multiplexer receives four channels of 14-bit digital data at a rate of up to 5 MHz per channel, and outputs a data stream to one of the FIFO memories at a rate of 20 MHz. The FIFO memories assert output data in parallel to the 64-bit bus, thus transferring 14-bit data values to the processor at a combined rate of 40 MHz. The real time processor is preferably a floating-point processor which processes 32-bit floating-point words. A set of mask bits is prestored in each 32-bit storage location of the processor memory into which a 14-bit data value is to be written. After data transfer from the FIFO memories, mask bits are concatenated with each stored 14-bit data value to define a valid 32-bit floating-point word. Preferably, a user can select any of several modes for starting and stopping direct memory transfers of data from the FIFO memories to memory within the real time processor, by setting the content of a control and status register.

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.

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

Route optimization as an instrument to improve animal welfare and economics in pre-slaughter logistics.

PubMed

Frisk, Mikael; Jonsson, Annie; Sellman, Stefan; Flisberg, Patrik; Rönnqvist, Mikael; Wennergren, Uno

2018-01-01

Each year, more than three million animals are transported from farms to abattoirs in Sweden. Animal transport is related to economic and environmental costs and a negative impact on animal welfare. Time and the number of pick-up stops between farms and abattoirs are two key parameters for animal welfare. Both are highly dependent on efficient and qualitative transportation planning, which may be difficult if done manually. We have examined the benefits of using route optimization in cattle transportation planning. To simulate the effects of various planning time windows and transportation time regulations and number of pick-up stops along each route, we have used data that represent one year of cattle transport. Our optimization model is a development of a model used in forestry transport that solves a general pick-up and delivery vehicle routing problem. The objective is to minimize transportation costs. We have shown that the length of the planning time window has a significant impact on the animal transport time, the total driving time and the total distance driven; these parameters that will not only affect animal welfare but also affect the economy and environment in the pre-slaughter logistic chain. In addition, we have shown that changes in animal transportation regulations, such as minimizing the number of allowed pick-up stops on each route or minimizing animal transportation time, will have positive effects on animal welfare measured in transportation hours and number of pick-up stops. However, this leads to an increase in working time and driven distances, leading to higher transportation costs for the transport and negative environmental impact.

Route optimization as an instrument to improve animal welfare and economics in pre-slaughter logistics

PubMed Central

2018-01-01

Each year, more than three million animals are transported from farms to abattoirs in Sweden. Animal transport is related to economic and environmental costs and a negative impact on animal welfare. Time and the number of pick-up stops between farms and abattoirs are two key parameters for animal welfare. Both are highly dependent on efficient and qualitative transportation planning, which may be difficult if done manually. We have examined the benefits of using route optimization in cattle transportation planning. To simulate the effects of various planning time windows and transportation time regulations and number of pick-up stops along each route, we have used data that represent one year of cattle transport. Our optimization model is a development of a model used in forestry transport that solves a general pick-up and delivery vehicle routing problem. The objective is to minimize transportation costs. We have shown that the length of the planning time window has a significant impact on the animal transport time, the total driving time and the total distance driven; these parameters that will not only affect animal welfare but also affect the economy and environment in the pre-slaughter logistic chain. In addition, we have shown that changes in animal transportation regulations, such as minimizing the number of allowed pick-up stops on each route or minimizing animal transportation time, will have positive effects on animal welfare measured in transportation hours and number of pick-up stops. However, this leads to an increase in working time and driven distances, leading to higher transportation costs for the transport and negative environmental impact. PMID:29513704

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.

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...

COMPARISON OF PARALLEL AND SERIES HYBRID POWERTRAINS FOR TRANSIT BUS APPLICATION

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

Gao, Zhiming; Daw, C Stuart; Smith, David E

2016-01-01

The fuel economy and emissions of both conventional and hybrid buses equipped with emissions aftertreatment were evaluated via computational simulation for six representative city bus drive cycles. Both series and parallel configurations for the hybrid case were studied. The simulation results indicate that series hybrid buses have the greatest overall advantage in fuel economy. The series and parallel hybrid buses were predicted to produce similar CO and HC tailpipe emissions but were also predicted to have reduced NOx tailpipe emissions compared to the conventional bus in higher speed cycles. For the New York bus cycle (NYBC), which has the lowestmore » average speed among the cycles evaluated, the series bus tailpipe emissions were somewhat higher than they were for the conventional bus, while the parallel hybrid bus had significantly lower tailpipe emissions. All three bus powertrains were found to require periodic active DPF regeneration to maintain PM control. Plug-in operation of series hybrid buses appears to offer significant fuel economy benefits and is easily employed due to the relatively large battery capacity that is typical of the series hybrid configuration.« less

Evaluation of an accelerated 3D SPACE sequence with compressed sensing and free-stop scan mode for imaging of the knee.

PubMed

Henninger, B; Raithel, E; Kranewitter, C; Steurer, M; Jaschke, W; Kremser, C

2018-05-01

To prospectively evaluate a prototypical 3D turbo-spin-echo proton-density-weighted sequence with compressed sensing and free-stop scan mode for preventing motion artefacts (3D-PD-CS-SPACE free-stop) for knee imaging in a clinical setting. 80 patients underwent 3T magnetic resonance imaging (MRI) of the knee with our 2D routine protocol and with 3D-PD-CS-SPACE free-stop. In case of a scan-stop caused by motion (images are calculated nevertheless) the sequence was repeated without free-stop mode. All scans were evaluated by 2 radiologists concerning image quality of the 3D-PD-CS-SPACE (with and without free-stop). Important knee structures were further assessed in a lesion based analysis and compared to our reference 2D-PD-fs sequences. Image quality of the 3D-PD-CS-SPACE free-stop was found optimal in 47/80, slightly compromised in 21/80, moderately in 10/80 and severely in 2/80. In 29/80, the free-stop scan mode stopped the 3D-PD-CS-SPACE due to subject motion with a slight increase of image quality at longer effective acquisition times. Compared to the 3D-PD-CS-SPACE with free-stop, the image quality of the acquired 3D-PD-CS-SPACE without free-stop was found equal in 6/29, slightly improved in 13/29, improved with equal contours in 8/29, and improved with sharper contours in 2/29. The lesion based analysis showed a high agreement between the results from the 3D-PD-CS-SPACE free-stop and our 2D-PD-fs routine protocol (overall agreement 96.25%-100%, Cohen's Kappa 0.883-1, p < 0.001). 3D-PD-CS-SPACE free-stop is a reliable alternative for standard 2D-PD-fs protocols with acceptable acquisition times. Copyright © 2018 Elsevier B.V. All rights reserved.

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

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

Barnitt, R.; Gonder, J.

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

Risk factors affecting fatal bus accident severity: Their impact on different types of bus drivers.

PubMed

Feng, Shumin; Li, Zhenning; Ci, Yusheng; Zhang, Guohui

2016-01-01

While the bus is generally considered to be a relatively safe means of transportation, the property losses and casualties caused by bus accidents, especially fatal ones, are far from negligible. The reasons for a driver to incur fatalities are different in each case, and it is essential to discover the underlying risk factors of bus fatality severity for different types of drivers in order to improve bus safety. The current study investigates the underlying risk factors of fatal bus accident severity to different types of drivers in the U.S. by estimating an ordered logistic model. Data for the analysis are retrieved from the Buses Involved in Fatal Accidents (BIFA) database from the USA for the years 2006-2010. Accidents are divided into three levels by counting their equivalent fatalities, and the drivers are classified into three clusters by the K-means cluster analysis. The analysis shows that some risk factors have the same impact on different types of drivers, they are: (a) season; (b) day of week; (c) time period; (d) number of vehicles involved; (e) land use; (f) manner of collision; (g) speed limit; (h) snow or ice surface condition; (i) school bus; (j) bus type and seating capacity; (k) driver's age; (l) driver's gender; (m) risky behaviors; and (n) restraint system. Results also show that some risk factors only have impact on the "young and elder drivers with history of traffic violations", they are: (a) section type; (b) number of lanes per direction; (c) roadway profile; (d) wet road surface; and (e) cyclist-bus accident. Notably, history of traffic violations has different impact on different types of bus drivers. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

PubMed

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

2005-09-01

Real-time and integrated measurements of gaseous and particulate pollutants were conducted inside five conventional diesel school buses, a diesel bus with a particulate trap, and a bus powered by compressed natural gas (CNG) to determine the range of children's exposures during school bus commutes and conditions leading to high exposures. Measurements were made during 24 morning and afternoon commutes on two Los Angeles Unified School District bus routes from South to West Los Angeles, with seven additional runs on a rural/suburban route, and three runs to test the effect of window position. For these commutes, the mean concentrations of diesel vehicle-related pollutants ranged from 0.9 to 19 microg/m(3) for black carbon, 23 to 400 ng/m(3) for particle-bound polycyclic aromatic hydrocarbon (PB-PAH), and 64 to 220 microg/m(3) for NO(2). Concentrations of benzene and formaldehyde ranged from 0.1 to 11 microg/m(3) and 0.3 to 5 microg/m(3), respectively. The highest real-time concentrations of black carbon, PB-PAH and NO(2) inside the buses were 52 microg/m(3), 2000 ng/m(3), and 370 microg/m(3), respectively. These pollutants were significantly higher inside conventional diesel buses compared to the CNG bus, although formaldehyde concentrations were higher inside the CNG bus. Mean black carbon, PB-PAH, benzene and formaldehyde concentrations were higher when the windows were closed, compared with partially open, in part, due to intrusion of the bus's own exhaust into the bus cabin, as demonstrated through the use of a tracer gas added to each bus's exhaust. These same pollutants tended to be higher on urban routes compared to the rural/suburban route, and substantially higher inside the bus cabins compared to ambient measurements. Mean concentrations of pollutants with substantial secondary formation, such as PM(2.5), showed smaller differences between open and closed window conditions and between bus routes. Type of bus, traffic congestion levels, and encounters with other diesel vehicles contributed to high exposure variability between runs.

Assessment of community satisfaction index of population and civil registration office in Malang municipal

NASA Astrophysics Data System (ADS)

Hakim, A. N.

2017-06-01

The demands and needs of the community will be the quality of public services in Malang increased, so that the Government of Malang as organizers and executors of public services must meet these demands. The Municipal Government in its efforts to improve public service performance, forming the regional One Stop Operator (PPTSP) with the goal will be to simplify and improve efficiency in administrative proceedings. But the existence of the one stop service is still not optimal because of the persistence of public complaints about the performance of the one stop service. This study will discuss the performance of services in service counter of Population and Civil Registration through community satisfaction index to measure the service level and the perception of satisfaction and interest to determine which variables are less optimal and need to be improved using IPA method. The results showed that the level of service at the service counter of Population and Civil Registration quite good. Meanwhile, according the results of IPA analysis, there are two important variables for the community on the performance / quality was lacking, namely the service procedure and time.

Microbial air quality in mass transport buses and work-related illness among bus drivers of Bangkok Mass Transit Authority.

PubMed

Luksamijarulkul, Pipat; Sundhiyodhin, Viboonsri; Luksamijarulkul, Soavalug; Kaewboonchoo, Orawan

2004-06-01

The air quality in mass transport buses, especially air-conditioned buses may affect bus drivers who work full time. Bus numbers 16, 63, 67 and 166 of the Seventh Bus Zone of Bangkok Mass Transit Authority were randomly selected to investigate for microbial air quality. Nine air-conditioned buses and 2-4 open-air buses for each number of the bus (36 air-conditioned buses and 12 open-air buses) were included. Five points of in-bus air samples in each studied bus were collected by using the Millipore A ir Tester Totally, 180 and 60 air samples collected from air-conditioned buses and open-air buses were cultured for bacterial and fungal counts. The bus drivers who drove the studied buses were interviewed towards histories of work-related illness while working. The results revealed that the mean +/- SD of bacterial counts in the studied open-air buses ranged from 358.50 +/- 146.66 CFU/m3 to 506 +/- 137.62 CFU/m3; bus number 16 had the highest level. As well as the mean +/- SD of fungal counts which ranged from 93.33 +/- 44.83 CFU/m3 to 302 +/- 294.65 CFU/m3; bus number 166 had the highest level. Whereas, the mean +/- SD of bacterial counts in the studied air-conditioned buses ranged from 115.24 +/- 136.01 CFU/m3 to 244.69 +/- 234.85 CFU/m3; bus numbers 16 and 67 had the highest level. As well as the mean +/- SD of fungal counts which rangedfrom 18.84 +/- 39.42 CFU/m3 to 96.13 +/- 234.76 CFU/m3; bus number 166 had the highest level. When 180 and 60 studied air samples were analyzed in detail, it was found that 33.33% of the air samples from open-air buses and 6.11% of air samples from air-conditioned buses had a high level of bacterial counts (> 500 CFU/m3) while 6.67% of air samples from open-air buses and 2.78% of air samples from air-conditioned buses had a high level of fungal counts (> 500 CFU/m3). Data from the history of work-related illnesses among the studied bus drivers showed that 91.67% of open-air bus drivers and 57.28% of air-conditioned bus drivers had symptoms of work-related illnesses, p = 0.0185.

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.

Big Data Discovery and Access Services through NOAA OneStop

NASA Astrophysics Data System (ADS)

Casey, K. S.; Neufeld, D.; Ritchey, N. A.; Relph, J.; Fischman, D.; Baldwin, R.

2017-12-01

The NOAA OneStop Project was created as a pathfinder effort to to improve the discovery of, access to, and usability of NOAA's vast and diverse collection of big data. OneStop is led by the NOAA/NESDIS National Centers for Environmental Information (NCEI), and is seen as a key NESDIS contribution to NOAA's open data and data stewardship efforts. OneStop consists of an entire framework of services, from storage and interoperable access services at the base, through metadata and catalog services in the middle, to a modern user interface experience at the top. Importantly, it is an open framework where external tools and services can connect at whichever level is most appropriate. Since the beta release of the OneStop user interface at the 2016 Fall AGU meeting, significant progress has been made improving and modernizing many NOAA data collections to optimize their use within the framework. In addition, OneStop has made progress implementing robust metadata management and catalog systems at the collection and granule level and improving the user experience with the web interface. This progress will be summarized and the results of extensive user testing including professional usability studies will be reviewed. Key big data technologies supporting the framework will be presented and a community input sought on the future directions of the OneStop Project.

Co-optimization of Energy and Demand-Side Reserves in Day-Ahead Electricity Markets

NASA Astrophysics Data System (ADS)

Surender Reddy, S.; Abhyankar, A. R.; Bijwe, P. R.

2015-04-01

This paper presents a new multi-objective day-ahead market clearing (DAMC) mechanism with demand-side reserves/demand response (DR) offers, considering realistic voltage-dependent load modeling. The paper proposes objectives such as social welfare maximization (SWM) including demand-side reserves, and load served error (LSE) minimization. In this paper, energy and demand-side reserves are cleared simultaneously through co-optimization process. The paper clearly brings out the unsuitability of conventional SWM for DAMC in the presence of voltage-dependent loads, due to reduction of load served (LS). Under such circumstances multi-objective DAMC with DR offers is essential. Multi-objective Strength Pareto Evolutionary Algorithm 2+ (SPEA 2+) has been used to solve the optimization problem. The effectiveness of the proposed scheme is confirmed with results obtained from IEEE 30 bus system.

Dynamic remedial action scheme using online transient stability analysis

NASA Astrophysics Data System (ADS)

Shrestha, Arun

Economic pressure and environmental factors have forced the modern power systems to operate closer to their stability limits. However, maintaining transient stability is a fundamental requirement for the operation of interconnected power systems. In North America, power systems are planned and operated to withstand the loss of any single or multiple elements without violating North American Electric Reliability Corporation (NERC) system performance criteria. For a contingency resulting in the loss of multiple elements (Category C), emergency transient stability controls may be necessary to stabilize the power system. Emergency control is designed to sense abnormal conditions and subsequently take pre-determined remedial actions to prevent instability. Commonly known as either Remedial Action Schemes (RAS) or as Special/System Protection Schemes (SPS), these emergency control approaches have been extensively adopted by utilities. RAS are designed to address specific problems, e.g. to increase power transfer, to provide reactive support, to address generator instability, to limit thermal overloads, etc. Possible remedial actions include generator tripping, load shedding, capacitor and reactor switching, static VAR control, etc. Among various RAS types, generation shedding is the most effective and widely used emergency control means for maintaining system stability. In this dissertation, an optimal power flow (OPF)-based generation-shedding RAS is proposed. This scheme uses online transient stability calculation and generator cost function to determine appropriate remedial actions. For transient stability calculation, SIngle Machine Equivalent (SIME) technique is used, which reduces the multimachine power system model to a One-Machine Infinite Bus (OMIB) equivalent and identifies critical machines. Unlike conventional RAS, which are designed using offline simulations, online stability calculations make the proposed RAS dynamic and adapting to any power system configuration and operating state. The generation-shedding cost is calculated using pre-RAS and post-RAS OPF costs. The criteria for selecting generators to trip is based on the minimum cost rather than minimum amount of generation to shed. For an unstable Category C contingency, the RAS control action that results in stable system with minimum generation shedding cost is selected among possible candidate solutions. The RAS control actions update whenever there is a change in operating condition, system configuration, or cost functions. The effectiveness of the proposed technique is demonstrated by simulations on the IEEE 9-bus system, the IEEE 39-bus system, and IEEE 145-bus system. This dissertation also proposes an improved, yet relatively simple, technique for solving Transient Stability-Constrained Optimal Power Flow (TSC-OPF) problem. Using the SIME method, the sets of dynamic and transient stability constraints are reduced to a single stability constraint, decreasing the overall size of the optimization problem. The transient stability constraint is formulated using the critical machines' power at the initial time step, rather than using the machine rotor angles. This avoids the addition of machine steady state stator algebraic equations in the conventional OPF algorithm. A systematic approach to reach an optimal solution is developed by exploring the quasi-linear behavior of critical machine power and stability margin. The proposed method shifts critical machines active power based on generator costs using an OPF algorithm. Moreover, the transient stability limit is based on stability margin, and not on a heuristically set limit on OMIB rotor angle. As a result, the proposed TSC-OPF solution is more economical and transparent. The proposed technique enables the use of fast and robust commercial OPF tool and time-domain simulation software for solving large scale TSC-OPF problem, which makes the proposed method also suitable for real-time application.

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

ERIC Educational Resources Information Center

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

Developed for teachers and members of the pupil transportation staff who conduct school bus drills, these 10 lesson outlines are intended for classroom instruction on school bus safety. Lessons may be adapted to fit the grade level, intelligence, and special needs of students. Topics covered are: preparing to ride the bus, boarding and proceeding…

Increasing security in inter-chip communication

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

Edwards, Nathan J.; Hamlet, Jason; Bauer, Todd

An apparatus for increasing security in inter-chip communication includes a sending control module, a communication bus, and a receiving control module. The communication bus is coupled between the sending control module and the receiving control module. The sending control module operates to send data on the communication bus, disable the communication bus when threats are detected, or both.

Bus-Programmable Slave Card

NASA Technical Reports Server (NTRS)

Hall, William A.

1990-01-01

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

School Bus Accidents and Driver Age.

ERIC Educational Resources Information Center

McMichael, Judith

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

Increasing security in inter-chip communication

DOEpatents

Edwards, Nathan J; Hamlet, Jason; Bauer, Todd; Helinski, Ryan

2014-10-28

An apparatus for increasing security in inter-chip communication includes a sending control module, a communication bus, and a receiving control module. The communication bus is coupled between the sending control module and the receiving control module. The sending control module operates to send data on the communication bus, disable the communication bus when threats are detected, or both.

49 CFR 571.222 - Standard No. 222; School bus passenger seating and crash protection.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 222; School bus passenger seating and... VEHICLE SAFETY STANDARDS Federal Motor Vehicle Safety Standards § 571.222 Standard No. 222; School bus... requirements for school bus passenger seating and restraining barriers. S2. Purpose. The purpose of this...

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…

The SMART MIL-STD-1553 bus adapter hardware manual

NASA Technical Reports Server (NTRS)

Ton, T. T.

1981-01-01

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

Energy Monitoring and Control Systems Operator Training - Recommended Qualifications, Staffing, Job Description, and Training Requirements for EMCS Operators.

DTIC Science & Technology

1982-06-01

start/stop chiller optimization , and demand limiting were added. The system monitors a 7,000 ton chiller plant and controls 74 air handlers. The EMCS does...Modify analog limits. g. Adjust setpoints of selected controllers. h. Select manual or automatic control modes. i. Enable and disable individual points...or event schedules and controller setpoints ; make nonscheduled starts and stops of equipment or disable field panels when required for routine

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.

Exploring the nearly degenerate stop region with sbottom decays

DOE PAGES

An, Haipeng; Gu, Jiayin; Wang, Lian-Tao

2017-04-13

A light stop with mass almost degenerate with the lightest neutralino has important connections with both naturalness and dark matter relic abundance. This region is also very hard to probe at colliders. In this paper, we demonstrate the potential of searching for such stop particles at the LHC from sbottom decays, focusing on two channels with final states 2ℓ+EmissT2ℓ+ETmiss and 1b1ℓ+Emore » $$miss\\atop{T}$$1b1ℓ+E$$miss\\atop{T}$$. We also found that, if the lightest sbottom has mass around or below 1 TeV and has a significant branching ratio to decay to stop and W($$\\tilde{b}$$→$$\\tilde{t}$$W), a stop almost degenerate with neutralino can be excluded up to about 500-600 GeV at the 13 TeV LHC with 300 fb -1 data. The searches we propose are complementary to other SUSY searches at the LHC and could have the best sensitivity to the stop-bino coannihilation region. Finally, since they involve final states which have already been used in LHC searches, a reinterpretation of the search results already has sensitivity. Further optimization could deliver the full potential of these channels.« less

An Optimal Partial Differential Equations-based Stopping Criterion for Medical Image Denoising.

PubMed

Khanian, Maryam; Feizi, Awat; Davari, Ali

2014-01-01

Improving the quality of medical images at pre- and post-surgery operations are necessary for beginning and speeding up the recovery process. Partial differential equations-based models have become a powerful and well-known tool in different areas of image processing such as denoising, multiscale image analysis, edge detection and other fields of image processing and computer vision. In this paper, an algorithm for medical image denoising using anisotropic diffusion filter with a convenient stopping criterion is presented. In this regard, the current paper introduces two strategies: utilizing the efficient explicit method due to its advantages with presenting impressive software technique to effectively solve the anisotropic diffusion filter which is mathematically unstable, proposing an automatic stopping criterion, that takes into consideration just input image, as opposed to other stopping criteria, besides the quality of denoised image, easiness and time. Various medical images are examined to confirm the claim.

Users' demographic profile and quality attributes of bus services: The perspectives of users, operators and local authorities

NASA Astrophysics Data System (ADS)

Noh, Nur'Amirah Mhd.; Hamid, Ahmad Hilmy Abd

2017-10-01

Bus services that can help meet almost every bus user's needs are the goals of bus operators. Despite such an idealistic view, the operators themselves, users and even the local authorities have been found to hold different views about the quality of service that the bus should deliver. As the users i.e., customers are considered as important stakeholders, understanding their characteristics, profile and pattern is very crucial. To this end, the present study has attempted to gauge the perspectives of all the above-mentioned stakeholders. For the users, a customer satisfaction survey was employed to look into the relative influence of service attributes. In addition, surveys were also administered to bus operators and local authorities to study their perspectives in relation to this matter. 450 randomly selected respondents were surveyed. Identification of the service level was analyzed through the Likert scale whereas the perspectives of the operators and authorities were dealt with through mean value Analysis. Specifically, this study aims to identify the crucial attributes in determining the quality of the bus services. Findings of the study indicated that different attributes were selected by users, operators and authorities, which clearly enlightened the variations of the important attributes in determining the level of bus service quality. In its attempt to compare the service level attributes from three perspectives, this study has helped advance better improvement and strategies for the urban public bus operators and planners, in addition to the authorities in delivering user-friendly bus services by taking into account the local context, user profile and demographic characteristics.

A decentralized software bus based on IP multicas ting

NASA Technical Reports Server (NTRS)

Callahan, John R.; Montgomery, Todd

1995-01-01

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

Preliminary Investigation of Workload on Intrastate Bus Traffic Controllers

NASA Astrophysics Data System (ADS)

Yen Bin, Teo; Azlis-Sani, Jalil; Nur Annuar Mohd Yunos, Muhammad; Ismail, S. M. Sabri S. M.; Tajedi, Noor Aqilah Ahmad

2016-11-01

The daily routine of bus traffic controller which involves high mental processes would have a direct impact on the level of workload. To date, the level of workload on the bus traffic controllers in Malaysia is relatively unknown. Excessive workload on bus traffic controllers would affect the control and efficiency of the system. This paper served to study the workload on bus traffic controllers and justify the needs to conduct further detailed research on this field. The objectives of this research are to identify the level of workload on the intrastate bus traffic controllers. Based on the results, recommendations will be proposed for improvements and future studies. The level of workload for the bus traffic controllers is quantified using questionnaire adapted from NASA TLX. Interview sessions were conducted for validation of workload. Sixteen respondents were involved and it was found that the average level of workload based on NASA TLX was 6.91. It was found that workload is not affected by gender and marital status. This study also showed that the level of workload and working experience of bus traffic controllers has a strong positive linear relationship. This study would serve as a guidance and reference related to this field. Since this study is a preliminary investigation, further detailed studies could be conducted to obtain a better comprehension regarding the bus traffic controllers.

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.

Application of Multi-Objective Human Learning Optimization Method to Solve AC/DC Multi-Objective Optimal Power Flow Problem

NASA Astrophysics Data System (ADS)

Cao, Jia; Yan, Zheng; He, Guangyu

2016-06-01

This paper introduces an efficient algorithm, multi-objective human learning optimization method (MOHLO), to solve AC/DC multi-objective optimal power flow problem (MOPF). Firstly, the model of AC/DC MOPF including wind farms is constructed, where includes three objective functions, operating cost, power loss, and pollutant emission. Combining the non-dominated sorting technique and the crowding distance index, the MOHLO method can be derived, which involves individual learning operator, social learning operator, random exploration learning operator and adaptive strategies. Both the proposed MOHLO method and non-dominated sorting genetic algorithm II (NSGAII) are tested on an improved IEEE 30-bus AC/DC hybrid system. Simulation results show that MOHLO method has excellent search efficiency and the powerful ability of searching optimal. Above all, MOHLO method can obtain more complete pareto front than that by NSGAII method. However, how to choose the optimal solution from pareto front depends mainly on the decision makers who stand from the economic point of view or from the energy saving and emission reduction point of view.

A Safe Ride to School; A Safe Ride Home.

ERIC Educational Resources Information Center

Illinois State Board of Education, Springfield.

Text and illustrations are used to teach safe school bus riding practices. The guide begins with instructions to parents or guardians to set a good example of safe behavior, and to help children learn safety rules and be on time. Instructions to children concern obeying the bus driver, boarding the bus, riding the bus, crossing the road, and using…

Perceptions of Heat Risk to Health: A Qualitative Study of Professional Bus Drivers and Their Managers in Jinan, China

PubMed Central

Zhou, Lin; Xin, Zheng; Bai, Li; Wan, Fangjun; Wang, Yongming; Sang, Shaowei; Liu, Shouqin; Zhang, Ji; Liu, Qiyong

2014-01-01

Summer extreme heat threatens the health of individuals, especially persons who are involved in outdoor activities. Ensuring the normal function of a city, bus drivers are among those who participate in outdoor physical activities and are exposed to excessive heat in hot summer weather. This qualitative study was performed to explore professional bus drivers’ in-depth views of extreme heat risks to their health, and ultimately develop targeted advice and policy interventions for city bus drivers. An interview-based study was performed among professional bus drivers in Jinan, China, including four focus groups with professional bus drivers (n = 37) and three interviews with their managers (n = 14). Five central themes or categories from the bus driver interviews were found: concerns about summer heat; health effects related to extreme heat; adaptive measures; barriers in implementing these adaptive measures; and suggested interventions. The beneficial role of cooling facilities (particularly air-conditioning) during extreme heat are addressed. The barriers not only impede the implementation of behavioral adaptive measures but also enhance the negative attitudes of bus drivers towards their effectiveness. The responsibilities of managers in promoting preventive actions are addressed. PMID:24477213

Comparison of Parallel and Series Hybrid Power Trains for Transit Bus Applications

DOE PAGES

Gao, Zhiming; Daw, C. Stuart; Smith, David E.; ...

2016-08-01

The fuel economy and emissions of conventional and hybrid buses equipped with emissions after treatment were evaluated via computational simulation for six representative city bus drive cycles. Both series and parallel configurations for the hybrid case were studied. The simulation results indicated that series hybrid buses have the greatest overall advantage in fuel economy. The series and parallel hybrid buses were predicted to produce similar carbon monoxide and hydrocarbon tailpipe emissions but were also predicted to have reduced tailpipe emissions of nitrogen oxides compared with the conventional bus in higher speed cycles. For the New York bus cycle, which hasmore » the lowest average speed among the cycles evaluated, the series bus tailpipe emissions were somewhat higher than they were for the conventional bus; the parallel hybrid bus had significantly lower tailpipe emissions. All three bus power trains were found to require periodic active diesel particulate filter regeneration to maintain control of particulate matter. Finally, plug-in operation of series hybrid buses appears to offer significant fuel economy benefits and is easily employed because of the relatively large battery capacity that is typical of the series hybrid configuration.« less

Comparison of Parallel and Series Hybrid Power Trains for Transit Bus Applications

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

Gao, Zhiming; Daw, C. Stuart; Smith, David E.

The fuel economy and emissions of conventional and hybrid buses equipped with emissions after treatment were evaluated via computational simulation for six representative city bus drive cycles. Both series and parallel configurations for the hybrid case were studied. The simulation results indicated that series hybrid buses have the greatest overall advantage in fuel economy. The series and parallel hybrid buses were predicted to produce similar carbon monoxide and hydrocarbon tailpipe emissions but were also predicted to have reduced tailpipe emissions of nitrogen oxides compared with the conventional bus in higher speed cycles. For the New York bus cycle, which hasmore » the lowest average speed among the cycles evaluated, the series bus tailpipe emissions were somewhat higher than they were for the conventional bus; the parallel hybrid bus had significantly lower tailpipe emissions. All three bus power trains were found to require periodic active diesel particulate filter regeneration to maintain control of particulate matter. Finally, plug-in operation of series hybrid buses appears to offer significant fuel economy benefits and is easily employed because of the relatively large battery capacity that is typical of the series hybrid configuration.« less

Power inverter with optical isolation

DOEpatents

Duncan, Paul G.; Schroeder, John Alan

2005-12-06

An optically isolated power electronic power conversion circuit that includes an input electrical power source, a heat pipe, a power electronic switch or plurality of interconnected power electronic switches, a mechanism for connecting the switch to the input power source, a mechanism for connecting comprising an interconnecting cable and/or bus bar or plurality of interconnecting cables and/or input bus bars, an optically isolated drive circuit connected to the switch, a heat sink assembly upon which the power electronic switch or switches is mounted, an output load, a mechanism for connecting the switch to the output load, the mechanism for connecting including an interconnecting cable and/or bus bar or plurality of interconnecting cables and/or output bus bars, at least one a fiber optic temperature sensor mounted on the heat sink assembly, at least one fiber optic current sensor mounted on the load interconnection cable and/or output bus bar, at least one fiber optic voltage sensor mounted on the load interconnection cable and/or output bus bar, at least one fiber optic current sensor mounted on the input power interconnection cable and/or input bus bar, and at least one fiber optic voltage sensor mounted on the input power interconnection cable and/or input bus bar.

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

Power management and control for space systems

NASA Technical Reports Server (NTRS)

Finke, R. C.; Myers, I. T.; Terdan, F. F.; Stevens, N. J.

1978-01-01

Power management and control technology for the large, high-power spacecraft of the 1980's is discussed. Systems weight optimization that indicate a need for higher bus voltages are shown. Environmental interactions that are practical limits for the maximum potential on exposed surfaces are shown. A dual-voltage system is proposed that would provide the weight savings of a high-voltage distribution system and take into account the potential environmental interactions. The technology development of new components and circuits is also discussed.

Small Business Innovation Research (SBIR) Program, FY 1994. Program Solicitation 94.1, Closing Date: 14 January 1994

DTIC Science & Technology

1994-01-01

is to design and develop a diode laser and ssociated driver circuitry with i•eh peak power, high pulse repetition frequency (PRF), and good beam...Computer modeling tools shall be used to design and optimize breadboard model of a multi-terminal high speed ring bus for flight critical applications... design , fabricate, and test a fiber optic interface device which will improve coupling of high energy, pulsed lasers into commercial fiber optics at a

Implementing a bubble memory hierarchy system

NASA Technical Reports Server (NTRS)

Segura, R.; Nichols, C. D.

1979-01-01

This paper reports on implementation of a magnetic bubble memory in a two-level hierarchial system. The hierarchy used a major-minor loop device and RAM under microprocessor control. Dynamic memory addressing, dual bus primary memory, and hardware data modification detection are incorporated in the system to minimize access time. It is the objective of the system to incorporate the advantages of bipolar memory with that of bubble domain memory to provide a smart, optimal memory system which is easy to interface and independent of user's system.

Speech-Enabled Interfaces for Travel Information Systems with Large Grammars

NASA Astrophysics Data System (ADS)

Zhao, Baoli; Allen, Tony; Bargiela, Andrzej

This paper introduces three grammar-segmentation methods capable of handling the large grammar issues associated with producing a real-time speech-enabled VXML bus travel application for London. Large grammars tend to produce relatively slow recognition interfaces and this work shows how this limitation can be successfully addressed. Comparative experimental results show that the novel last-word recognition based grammar segmentation method described here achieves an optimal balance between recognition rate, speed of processing and naturalness of interaction.

Fault tolerant data management system

NASA Technical Reports Server (NTRS)

Gustin, W. M.; Smither, M. A.

1972-01-01

Described in detail are: (1) results obtained in modifying the onboard data management system software to a multiprocessor fault tolerant system; (2) a functional description of the prototype buffer I/O units; (3) description of modification to the ACADC and stimuli generating unit of the DTS; and (4) summaries and conclusions on techniques implemented in the rack and prototype buffers. Also documented is the work done in investigating techniques of high speed (5 Mbps) digital data transmission in the data bus environment. The application considered is a multiport data bus operating with the following constraints: no preferred stations; random bus access by all stations; all stations equally likely to source or sink data; no limit to the number of stations along the bus; no branching of the bus; and no restriction on station placement along the bus.

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.

Hydrogen-oxygen driven Zero Emissions bus drives around KSC Visitor Complex

NASA Technical Reports Server (NTRS)

1999-01-01

The Zero Emissions (ZE) transit bus passes a mock-up orbiter named Explorer on a trek through the KSC Visitor Complex. 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. The ZE bus is being used on tour routes at the KSC Visitor Complex for two days to introduce the public to the concept.

Content-addressable memory based enforcement of configurable policies

DOEpatents

Berg, Michael J

2014-05-06

A monitoring device for monitoring transactions on a bus includes content-addressable memory ("CAM") and a response policy unit. The CAM includes an input coupled to receive a bus transaction tag based on bus traffic on the bus. The CAM stores data tags associated with rules of a security policy to compare the bus transaction tag to the data tags. The CAM generates an output signal indicating whether one or more matches occurred. The response policy unit is coupled to the CAM to receive the output signal from the CAM and to execute a policy action in response to the output signal.

Hydrogen powered bus

ScienceCinema

Glass, Bob; Mathis, Mike; Cochran, Ron; Garback, John

2018-06-08

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

Ten bar probe technical summary. [feasibility of outer planet common atmospheric probe

NASA Technical Reports Server (NTRS)

Ellis, T. R.

1974-01-01

The feasibility of an outer planet common atmospheric probe is studied with emphasis on entry heating rates and improved ephemeris. It is concluded that a common probe design is possible except for Jupiter; the basic technology exists except for Jupiter heat shielding. A Mariner class bus provides for better bus science and probe bus communications than a Pioneer class bus.

Multi-access fiber optic data bus using FDM/FSK

NASA Technical Reports Server (NTRS)

Zanger, H.

1984-01-01

The major thrust was to develop a T coupler with very low (0.1 0.2dB) in-line loss. This is essential to any multiaccess bus structure where the word multi implies fifteen or more nodes on the bus, and it is tacitly assumed to be a passive bus. (Reliability considerations tend to exclude the use of active nodes - repeater nodes.)

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.

Behavior Modification of Aggressive Behavior on a Nursery School Bus: A Case Study.1

ERIC Educational Resources Information Center

Whitehurst, Carol; Miller, Edward

1973-01-01

A case study is presented in which aggressive behavior of two pre-school boys on a nursery school bus was modified by the introduction of a negative punishment contingency in which the Ss were told they would be detained on the bus until the second time the bus passed their house (delay of reinforcement) if abusive behavior occurred. (Author)

The ins and outs of terrorist bus explosions: injury profiles of on-board explosions versus explosions occurring adjacent to a bus.

PubMed

Golan, Ron; Soffer, Dror; Givon, Adi; Peleg, Kobi

2014-01-01

Terrorist explosions occurring in varying settings have been shown to lead to significantly different injury patterns among the victims, with more severe injuries generally arising in confined space attacks. Increasing numbers of terrorist attacks have been targeted at civilian buses, yet most studies focus on events in which the bomb was detonated within the bus. This study focuses on the injury patterns and hospital utilisation among casualties from explosive terrorist bus attacks with the bomb detonated either within a bus or adjacent to a bus. All patients hospitalised at six level I trauma centres and four large regional trauma centres following terrorist explosions that occurred in and adjacent to buses in Israel between November 2000 and August 2004 were reviewed. Injury severity scores (ISS) were used to assess severity. Hospital utilisation data included length of hospital stay, surgical procedures performed, and intensive care unit (ICU) admission. The study included 262 victims of 22 terrorist attacks targeted at civilian bus passengers and drivers; 171 victims were injured by an explosion within a bus (IB), and 91 were injured by an explosion adjacent to a bus (AB). Significant differences were noted between the groups, with the IB population having higher ISS scores, more primary blast injury, more urgent surgical procedures performed, and greater ICU utilisation. Both groups had percentages of nearly 20% for burn injury, had high percentages of injuries to the head/neck, and high percentages of surgical wound and burn care. Explosive terrorist attacks detonated within a bus generate more severe injuries among the casualties and require more urgent surgical and intensive level care than attacks occurring adjacent to a bus. The comparison and description of the outcomes to these terrorist attacks should aid in the preparation and response to such devastating events. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

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

Truett, L.F.; Moore, S.; Tonn, B.

1998-07-01

Although major accidents involving school buses are rare (only about 0.3% of all fatal crashes since 1986 are classified as school-bus-related), even minor accidents and breakdowns cause a great deal of parental anxiety. The objective of this research is to design an efficient, cost-effective, accurate, and secure system that will track individual school buses and communicate appropriate information to the school system`s central administration unit, to the school transportation administrator, and to parents of children on the bus. The greatest benefit of the proposed information system is that parents and officials can always know the location and condition (these conditionsmore » would vary depending on the needs of a particular school system) of the school buses. In case of an accident or mechanical problem, when emergency crews are needed, they can be dispatched almost immediately with a good understanding of the problem and the exact location of the bus. In addition to being able to track the bus while the child is on board, parents will be able to determine the location of their child`s bus prior to its arrival in the morning in order to prevent the child from needing to wait outside in inclement weather. The information available to parents can also be expanded to include maps of limited routes (e.g., snow routes). Basically, the Bus 54 concept consists of a bus component and a central data processing unit. Each bus will be outfitted with a global positioning satellite (GPS) device, a wireless communication device, and wireless data communication service. The central data processing unit will receive and process information from the buses and provide information access to parents and officials via an Internet link.« less

Monotop signature from the supersymmetric t t¯ H channel

NASA Astrophysics Data System (ADS)

Gonçalves, Dorival; Sakurai, Kazuki; Takeuchi, Michihisa

2016-10-01

We point out that a distinctive monotop signature is present in natural supersymmetry scenarios when a scalar top quark and Higgsinos are almost mass degenerate. This signature originates from a supersymmetric counterpart of the t t ¯H process, i.e. p p →t ˜t h ˜. Unlike monojet signatures exploiting initial state radiation, this channel can be regarded as a clear signature of a light stop and Higgsinos, allowing a direct probe of the stop and neutralino sectors. The production rate of this channel largely depends on the up-type Higgsino components in the neutralinos while the stop sector is sensitive to angular distributions of the top-quark's decay products. We develop an optimal search strategy to capture the supersymmetric t t ¯ H process and find that a high luminosity LHC can probe the stop and Higgsino sectors with mt˜1≲380 GeV and mt˜1-mχ˜1 0≲mW . Additionally, we propose a kinematic variable with which one can measure the stop mixing in this channel.

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.

Listing of New Bus Technology Applications

DOT National Transportation Integrated Search

1983-12-01

The New Bus Equipment Introduction program is designed to demonstrate innovative features on transit buses and encourage the adoption of innovative features that enhance productivity. New bus demonstrations and purchases have been catalogued for the ...

KSC-99pp1251

NASA Image and Video Library

1999-10-25

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

Method and systems for a radiation tolerant bus interface circuit

NASA Technical Reports Server (NTRS)

Kinstler, Gary A. (Inventor)

2007-01-01

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

Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC

NASA Technical Reports Server (NTRS)

1999-01-01

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

Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC

NASA Technical Reports Server (NTRS)

1999-01-01

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

Hydrogen-oxygen driven Zero Emissions bus draws attention at KSC

NASA Technical Reports Server (NTRS)

1999-01-01

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

TMS communications software. Volume 1: Computer interfaces

NASA Technical Reports Server (NTRS)

Brown, J. S.; Lenker, M. D.

1979-01-01

A prototype bus communications system, which is being used to support the Trend Monitoring System (TMS) as well as for evaluation of the bus concept is considered. Hardware and software interfaces to the MODCOMP and NOVA minicomputers are included. The system software required to drive the interfaces in each TMS computer is described. Documentation of other software for bus statistics monitoring and for transferring files across the bus is also included.

Scheduled Peripheral Component Interconnect Arbiter

NASA Technical Reports Server (NTRS)

Nixon, Scott Alan (Inventor)

2015-01-01

Systems and methods are described for arbitrating access of a communication bus. In one embodiment, a method includes performing steps on one or more processors. The steps include: receiving an access request from a device of the communication bus; evaluating a bus schedule to determine an importance of the device based on the access request; and selectively granting access of the communication bus to the device based on the importance of the device.

A study of multiplex data bus techniques for the space shuttle

NASA Technical Reports Server (NTRS)

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

1972-01-01

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

Vibration energy harvesting with polyphase AC transducers

NASA Astrophysics Data System (ADS)

McCullagh, James J.; Scruggs, Jeffrey T.; Asai, Takehiko

2016-04-01

Three-phase transduction affords certain advantages in the efficient electromechanical conversion of energy, especially at higher power scales. This paper considers the use of a three-phase electric machine for harvesting energy from vibrations. We consider the use of vector control techniques, which are common in the area of industrial electronics, for optimizing the feedback loops in a stochastically-excited energy harvesting system. To do this, we decompose the problem into two separate feedback loops for direct and quadrature current components, and illustrate how each might be separately optimized to maximize power output. In a simple analytical example, we illustrate how these techniques might be used to gain insight into the tradeoffs in the design of the electronic hardware and the choice of bus voltage.

Countermeasures for Developing New Energy Bus Standards in China

NASA Astrophysics Data System (ADS)

Shi, Xin

2018-01-01

With the rapid development of new energy vehicle technology, new energy bus has become more and more popular in China, and the relevant standards and policy are urgently needed to guide the market. According to the assessment of the development situation on new energy vehicle technology and new energy bus, combing with traffic policy guidance and the development trend of new energy vehicles, this paper aims to put forward the countermeasures of the new energy bus standard in China, including standard system, key standards and relevant recommendations. Research result is expected to provide decision support for the wide application of new energy bus in China.

Improved approach for electric vehicle rapid charging station placement and sizing using Google maps and binary lightning search algorithm

PubMed Central

Shareef, Hussain; Mohamed, Azah

2017-01-01

The electric vehicle (EV) is considered a premium solution to global warming and various types of pollution. Nonetheless, a key concern is the recharging of EV batteries. Therefore, this study proposes a novel approach that considers the costs of transportation loss, buildup, and substation energy loss and that incorporates harmonic power loss into optimal rapid charging station (RCS) planning. A novel optimization technique, called binary lightning search algorithm (BLSA), is proposed to solve the optimization problem. BLSA is also applied to a conventional RCS planning method. A comprehensive analysis is conducted to assess the performance of the two RCS planning methods by using the IEEE 34-bus test system as the power grid. The comparative studies show that the proposed BLSA is better than other optimization techniques. The daily total cost in RCS planning of the proposed method, including harmonic power loss, decreases by 10% compared with that of the conventional method. PMID:29220396

Improved approach for electric vehicle rapid charging station placement and sizing using Google maps and binary lightning search algorithm.

PubMed

Islam, Md Mainul; Shareef, Hussain; Mohamed, Azah

2017-01-01

The electric vehicle (EV) is considered a premium solution to global warming and various types of pollution. Nonetheless, a key concern is the recharging of EV batteries. Therefore, this study proposes a novel approach that considers the costs of transportation loss, buildup, and substation energy loss and that incorporates harmonic power loss into optimal rapid charging station (RCS) planning. A novel optimization technique, called binary lightning search algorithm (BLSA), is proposed to solve the optimization problem. BLSA is also applied to a conventional RCS planning method. A comprehensive analysis is conducted to assess the performance of the two RCS planning methods by using the IEEE 34-bus test system as the power grid. The comparative studies show that the proposed BLSA is better than other optimization techniques. The daily total cost in RCS planning of the proposed method, including harmonic power loss, decreases by 10% compared with that of the conventional method.

A Method for Optimal Load Dispatch of a Multi-zone Power System with Zonal Exchange Constraints

NASA Astrophysics Data System (ADS)

Hazarika, Durlav; Das, Ranjay

2018-04-01

This paper presented a method for economic generation scheduling of a multi-zone power system having inter zonal operational constraints. For this purpose, the generator rescheduling for a multi area power system having inter zonal operational constraints has been represented as a two step optimal generation scheduling problem. At first, the optimal generation scheduling has been carried out for the zone having surplus or deficient generation with proper spinning reserve using co-ordination equation. The power exchange required for the deficit zones and zones having no generation are estimated based on load demand and generation for the zone. The incremental transmission loss formulas for the transmission lines participating in the power transfer process among the zones are formulated. Using these, incremental transmission loss expression in co-ordination equation, the optimal generation scheduling for the zonal exchange has been determined. Simulation is carried out on IEEE 118 bus test system to examine the applicability and validity of the method.

Annoyance evaluation and the effect of noise on the health of bus drivers.

PubMed

Bruno, Portela S; Marcos, Queiroga R; Amanda, Constantini; Paulo, Zannin H T

2013-01-01

In the present study, we evaluated annoyance and the effects of noise on the health of bus drivers. For that, 200 bus drivers from a public transport company participated in a cross-sectional study. Annoyance and effects on health was measured with analog scale: Sleep quality, occurrence of tinnitus, headache, irritation, and annoyance from bus engine, traffic, and passengers. Data of age and working time of bus drivers also were obtained. For noise exposure, LA eq was evaluated in 80 buses. Statistical analysis consisted of mean, standard deviation, minimum, and maximum, Kruskal-Wallis test with post-hoc Dunn, one-way ANOVA with post-hoc Tukey and Spearman's correlation coefficient. Results indicate three groups of bus drivers (not annoyed: (N.A.), a little annoyed (L.A.) and highly annoyed (H.A.)). The group H.A. was younger and with less working time in relation to others, with a significant difference only for age. Regarding sleep quality, there was no significant difference. For results on the occurrence of tinnitus, headache and irritation after work, group H.A. had significantly higher means. Result of annoyance to the bus engine was significantly higher in H.A. than in L.A. and N.A. Annoyance to traffic and passengers, no significant differences were found, but the highest results were found for L.A., followed by H.A. and N.A. Equivalent sound pressure level in buses was above of the limit for occupational comfort. It was concluded that bus drivers has considerable level of noise annoyance and some health effects are perceived. The noise is a factor discomfort ergonomic that may cause effects on health of bus drivers. This study aims to evaluate annoyance and the effects of noise on the health of bus drivers. Cross-sectional study with buses and bus drivers. For that, 200 bus drivers from a public transport company participated in a cross-sectional study. Annoyance and effects on health was measured with analog scale: Sleep quality, occurrence of tinnitus, headache, irritation and annoyance from bus engine, traffic, and passengers. Data of age and working time of bus drivers also were obtained. For noise exposure, LA eq was evaluated in 80 buses. Statistical analysis consisted of mean, standard deviation, minimum and maximum, Kruskal-Wallis test with post-hoc Dunn, one-way ANOVA with post-hoc Tukey and Spearman's correlation coefficient. Results indicate three groups of bus drivers (N.A., a L.A. and H.A.). The group H.A. was younger and with less working time in relation to others, with a significant difference only for age. Regarding sleep quality, there was no significant difference. For results on the occurrence of tinnitus, headache and irritation after work, group H.A. had significantly higher means. Result of annoyance to the bus engine was significantly higher in H.A. than in L.A. and N.A. Annoyance to traffic and passengers, no significant differences were found, but the highest results were found for L.A., followed by H.A. and N.A. Equivalent sound pressure level in buses was above of the limit for occupational comfort. It was concluded that bus drivers has considerable level of noise annoyance and some health effects are perceived.

Survey of transit bus maintenance programs in Virginia.

DOT National Transportation Integrated Search

1981-01-01

Transit bus maintenance practices as used by thirteen small and medium-sized transit systems in Virginia were cataloged. Different approaches to maintenance were investigated and the current condition of transit bus maintenance was determined. Factor...

Coordinated distribution network control of tap changer transformers, capacitors and PV inverters

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

Ceylan, Oğuzhan; Liu, Guodong; Tomsovic, Kevin

A power distribution system operates most efficiently with voltage deviations along a feeder kept to a minimum and must ensure all voltages remain within specified limits. Recently with the increased integration of photovoltaics, the variable power output has led to increased voltage fluctuations and violation of operating limits. This study proposes an optimization model based on a recently developed heuristic search method, grey wolf optimization, to coordinate the various distribution controllers. Several different case studies on IEEE 33 and 69 bus test systems modified by including tap changing transformers, capacitors and photovoltaic solar panels are performed. Simulation results are comparedmore » to two other heuristic-based optimization methods: harmony search and differential evolution. Finally, the simulation results show the effectiveness of the method and indicate the usage of reactive power outputs of PVs facilitates better voltage magnitude profile.« less

Coordinated distribution network control of tap changer transformers, capacitors and PV inverters

DOE PAGES

Ceylan, Oğuzhan; Liu, Guodong; Tomsovic, Kevin

2017-06-08

A power distribution system operates most efficiently with voltage deviations along a feeder kept to a minimum and must ensure all voltages remain within specified limits. Recently with the increased integration of photovoltaics, the variable power output has led to increased voltage fluctuations and violation of operating limits. This study proposes an optimization model based on a recently developed heuristic search method, grey wolf optimization, to coordinate the various distribution controllers. Several different case studies on IEEE 33 and 69 bus test systems modified by including tap changing transformers, capacitors and photovoltaic solar panels are performed. Simulation results are comparedmore » to two other heuristic-based optimization methods: harmony search and differential evolution. Finally, the simulation results show the effectiveness of the method and indicate the usage of reactive power outputs of PVs facilitates better voltage magnitude profile.« less

Stochastic DG Placement for Conservation Voltage Reduction Based on Multiple Replications Procedure

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

Wang, Zhaoyu; Chen, Bokan; Wang, Jianhui

2015-06-01

Conservation voltage reduction (CVR) and distributed-generation (DG) integration are popular strategies implemented by utilities to improve energy efficiency. This paper investigates the interactions between CVR and DG placement to minimize load consumption in distribution networks, while keeping the lowest voltage level within the predefined range. The optimal placement of DG units is formulated as a stochastic optimization problem considering the uncertainty of DG outputs and load consumptions. A sample average approximation algorithm-based technique is developed to solve the formulated problem effectively. A multiple replications procedure is developed to test the stability of the solution and calculate the confidence interval ofmore » the gap between the candidate solution and optimal solution. The proposed method has been applied to the IEEE 37-bus distribution test system with different scenarios. The numerical results indicate that the implementations of CVR and DG, if combined, can achieve significant energy savings.« less

Short-Term State Forecasting-Based Optimal Voltage Regulation in Distribution Systems: Preprint

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

Yang, Rui; Jiang, Huaiguang; Zhang, Yingchen

2017-05-17

A novel short-term state forecasting-based optimal power flow (OPF) approach for distribution system voltage regulation is proposed in this paper. An extreme learning machine (ELM) based state forecaster is developed to accurately predict system states (voltage magnitudes and angles) in the near future. Based on the forecast system states, a dynamically weighted three-phase AC OPF problem is formulated to minimize the voltage violations with higher penalization on buses which are forecast to have higher voltage violations in the near future. By solving the proposed OPF problem, the controllable resources in the system are optimally coordinated to alleviate the potential severemore » voltage violations and improve the overall voltage profile. The proposed approach has been tested in a 12-bus distribution system and simulation results are presented to demonstrate the performance of the proposed approach.« less

Distributed Optimal Consensus Over Resource Allocation Network and Its Application to Dynamical Economic Dispatch.

PubMed

Li, Chaojie; Yu, Xinghuo; Huang, Tingwen; He, Xing; Chaojie Li; Xinghuo Yu; Tingwen Huang; Xing He; Li, Chaojie; Huang, Tingwen; He, Xing; Yu, Xinghuo

2018-06-01

The resource allocation problem is studied and reformulated by a distributed interior point method via a -logarithmic barrier. By the facilitation of the graph Laplacian, a fully distributed continuous-time multiagent system is developed for solving the problem. Specifically, to avoid high singularity of the -logarithmic barrier at boundary, an adaptive parameter switching strategy is introduced into this dynamical multiagent system. The convergence rate of the distributed algorithm is obtained. Moreover, a novel distributed primal-dual dynamical multiagent system is designed in a smart grid scenario to seek the saddle point of dynamical economic dispatch, which coincides with the optimal solution. The dual decomposition technique is applied to transform the optimization problem into easily solvable resource allocation subproblems with local inequality constraints. The good performance of the new dynamical systems is, respectively, verified by a numerical example and the IEEE six-bus test system-based simulations.

Corrective Control to Handle Forecast Uncertainty: A Chance Constrained Optimal Power Flow

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

Roald, Line; Misra, Sidhant; Krause, Thilo

Higher shares of electricity generation from renewable energy sources and market liberalization is increasing uncertainty in power systems operation. At the same time, operation is becoming more flexible with improved control systems and new technology such as phase shifting transformers (PSTs) and high voltage direct current connections (HVDC). Previous studies have shown that the use of corrective control in response to outages contributes to a reduction in operating cost, while maintaining N-1 security. In this work, we propose a method to extend the use of corrective control of PSTs and HVDCs to react to uncertainty. We characterize the uncertainty asmore » continuous random variables, and define the corrective control actions through affine control policies. This allows us to efficiently model control reactions to a large number of uncertainty sources. The control policies are then included in a chance constrained optimal power flow formulation, which guarantees that the system constraints are enforced with a desired probability. Lastly, by applying an analytical reformulation of the chance constraints, we obtain a second-order cone problem for which we develop an efficient solution algorithm. In a case study for the IEEE 118 bus system, we show that corrective control for uncertainty leads to a decrease in operational cost, while maintaining system security. Further, we demonstrate the scalability of the method by solving the problem for the IEEE 300 bus and the Polish system test cases.« less

Corrective Control to Handle Forecast Uncertainty: A Chance Constrained Optimal Power Flow

DOE PAGES

Roald, Line; Misra, Sidhant; Krause, Thilo; ...

2016-08-25

Higher shares of electricity generation from renewable energy sources and market liberalization is increasing uncertainty in power systems operation. At the same time, operation is becoming more flexible with improved control systems and new technology such as phase shifting transformers (PSTs) and high voltage direct current connections (HVDC). Previous studies have shown that the use of corrective control in response to outages contributes to a reduction in operating cost, while maintaining N-1 security. In this work, we propose a method to extend the use of corrective control of PSTs and HVDCs to react to uncertainty. We characterize the uncertainty asmore » continuous random variables, and define the corrective control actions through affine control policies. This allows us to efficiently model control reactions to a large number of uncertainty sources. The control policies are then included in a chance constrained optimal power flow formulation, which guarantees that the system constraints are enforced with a desired probability. Lastly, by applying an analytical reformulation of the chance constraints, we obtain a second-order cone problem for which we develop an efficient solution algorithm. In a case study for the IEEE 118 bus system, we show that corrective control for uncertainty leads to a decrease in operational cost, while maintaining system security. Further, we demonstrate the scalability of the method by solving the problem for the IEEE 300 bus and the Polish system test cases.« less

a New Multimodal Multi-Criteria Route Planning Model by Integrating a Fuzzy-Ahp Weighting Method and a Simulated Annealing Algorithm

NASA Astrophysics Data System (ADS)

Ghaderi, F.; Pahlavani, P.

2015-12-01

A multimodal multi-criteria route planning (MMRP) system provides an optimal multimodal route from an origin point to a destination point considering two or more criteria in a way this route can be a combination of public and private transportation modes. In this paper, the simulate annealing (SA) and the fuzzy analytical hierarchy process (fuzzy AHP) were combined in order to find this route. In this regard, firstly, the effective criteria that are significant for users in their trip were determined. Then the weight of each criterion was calculated using the fuzzy AHP weighting method. The most important characteristic of this weighting method is the use of fuzzy numbers that aids the users to consider their uncertainty in pairwise comparison of criteria. After determining the criteria weights, the proposed SA algorithm were used for determining an optimal route from an origin to a destination. One of the most important problems in a meta-heuristic algorithm is trapping in local minima. In this study, five transportation modes, including subway, bus rapid transit (BRT), taxi, walking, and bus were considered for moving between nodes. Also, the fare, the time, the user's bother, and the length of the path were considered as effective criteria for solving the problem. The proposed model was implemented in an area in centre of Tehran in a GUI MATLAB programming language. The results showed a high efficiency and speed of the proposed algorithm that support our analyses.

Intercity bus service in Virginia.

DOT National Transportation Integrated Search

1981-01-01

The intercity bus industry in Virginia was examined to gain information on the status of the industry and to determine the likely impacts of state policy options relating to assistance and deregulation on the industry. The national intercity bus indu...

LYMMO BRT : 15 years later.

DOT National Transportation Integrated Search

2013-06-01

LYMMO bus rapid transit service began in August 1997 in Orlando, Florida, : as one of the first bus-based premium downtown circulators in the U.S. Its : construction was funded, in part, by the Federal Transit Administrations (FTAs) : Bus Rapid...

75 FR 61341 - Airworthiness Directives; Agusta S.p.A. (Agusta) Model A109E Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-05

... electrical failure, an investigation revealed inadequate functioning of the 35 amperes (Amps) battery bus... investigation revealed inadequate functioning of the 35 amperes (Amps) battery bus (BATT BUS) circuit breaker...

Simulation of an Urban Battery Bus Vehicle

DOT National Transportation Integrated Search

1979-07-01

This report describes the computer simulation of a battery-powered bus as it traverses an arbitrary mission profile of specified acceleration, roadway grade, and headwind. The battery-bus system components comprise a DC shunt motor, solid-state power...

Evaluation guidelines for bus rapid transit demonstration projects

DOT National Transportation Integrated Search

2002-02-01

The Federal Transit Administration's (FTA) Bus Rapid Transit Demonstration Program is supporting demonstrations of Bus Rapid Transit (BRT) in selected cities across the United States. The US BRT Demonstration Program aims to adapt the principles of h...

Electric bus systems.

DOT National Transportation Integrated Search

2017-04-01

Pure electric buses (EBs) offer an alternative fuel for the nations transit bus systems. To : evaluate EBs in a transit setting, this project investigated the five electric bus fleet of the : StarMetro transit system of the city of Tallahassee, FL...

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

NASA Technical Reports Server (NTRS)

Flanegan, Mark; Label, Ken

1992-01-01

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

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...

Methods of computing steady-state voltage stability margins of power systems

DOEpatents

Chow, Joe Hong; Ghiocel, Scott Gordon

2018-03-20

In steady-state voltage stability analysis, as load increases toward a maximum, conventional Newton-Raphson power flow Jacobian matrix becomes increasingly ill-conditioned so power flow fails to converge before reaching maximum loading. A method to directly eliminate this singularity reformulates the power flow problem by introducing an AQ bus with specified bus angle and reactive power consumption of a load bus. For steady-state voltage stability analysis, the angle separation between the swing bus and AQ bus can be varied to control power transfer to the load, rather than specifying the load power itself. For an AQ bus, the power flow formulation is only made up of a reactive power equation, thus reducing the size of the Jacobian matrix by one. This reduced Jacobian matrix is nonsingular at the critical voltage point, eliminating a major difficulty in voltage stability analysis for power system operations.

Hydrogen-oxygen driven Zero Emissions bus drives around KSC Visitor Complex

NASA Technical Reports Server (NTRS)

1999-01-01

The Zero Emissions (ZE) transit bus tours the KSC Visitor Complex for a test ride. In the background are a mock-up orbiter named Explorer (left) and a stack of solid rocket boosters and external tank (right), typically used on Shuttle launches. 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. The ZE bus is being used on tour routes at the KSC Visitor Complex for two days to introduce the public to the concept.

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.

Online Assessment of Voltage Stability in Power Systems with PMUs

NASA Astrophysics Data System (ADS)

Chitare, Prasad Bhagwat; Murthy Balijepalli, V. S. K.; Khaparde, S. A.

2013-05-01

Abstract: For the assessment of voltage instability which comprises the detection of voltage instability and identification of critical buses, two indices namely, system wide Qtax, and bus-specific qtax, are proposed. The Qtax, based on the sensitivity of the reactive power injections to the loading in the system provides early detection of impending voltage instability. The computed qtax indices identify the critcal buses among the load buses in the system. The identified critical buses provided optimal lacations for the corrective control actions for averting voltage instability. Additionally, for voltage stability monitoring, determining the poing of exhaustion of the reactive reserves in system is also crucial. This is addressed by proposed Q-Monitoring Index (QMI), which is the ratio of the reactive component of the source current to the sink current that flows through the adjacent transmission line. These proposed indices together can provide early indication to impending voltage instability. This has been illustrated on IEEE-39 bus system. The reactive support on identified critical buses results in maximum increase in the loadability of the system.

Decreasing the exhaust outlet temperatures on a class III bus with the lowest impact on the exhaust backpressure and the fuel consumption

NASA Astrophysics Data System (ADS)

Aslan, E.; Ozturk, Y.; Dileroglu, S.

2017-07-01

The focus of this study is to determine the most appropriate exhaust tail pipe form among three different type of designs with respect to their temperature loss efficiency for a 9.5m intercity bus equipped with an Euro VI diesel engine and an automated transmission. To provide lower temperatures at the exhaust outlet, mentioned designs were submitted on to a CFD simulation using Ansys Fluent 17.1, while for manufactured products, temperature measurement tests were conducted in an environmental chamber with Omega K-type thermocouples, and Flir T420 thermal camera was used to monitor outer surface temperature distributions to make a comparison between theoretical and practical results. In order to obtain these practical results, actual tests were performed in an environmental chamber with a constant ambient temperature during the vehicle exhaust emission system regeneration process. In conclusion, an exhaust tail pipe design with a diffuser having a circular contraction and expansion forms is designated since it was the most optimized option in terms of temperature loss efficiency, inconsiderable exhaust backpressure increase and manufacturing costs.