WorldWideScience

Sample records for commute mode choice

  1. What affects commute mode choice: Physical neighborhood structure or preferences toward neighborhoods?

    NARCIS (Netherlands)

    Schwanen, T.; Mokhtarian, P.L.

    2005-01-01

    The academic literature on the impact of urban form on travel behavior has increasingly recognized that residential location choice and travel choices may be interconnected. We contribute to the understanding of this interrelation by studying to what extent commute mode choice differs by

  2. The influence of travel attitudes, commute mode choice, and perceived neighborhood characteristics on physical activity.

    Science.gov (United States)

    Morckel, Victoria; Terzano, Kathryn

    2014-01-01

    This study examines the relationships between physical activity, travel attitudes, commute mode choice, and perceived neighborhood characteristics. A recent study found that people who walk or bike during their commute exercise more outside of the commute than do people who commute by mass transit or car. The current study seeks to explain what might account for this relationship, using ANOVA models (Method) conducted on survey data from 3 cities. Perceived neighborhood characteristics and travel attitudes influence participants' reported physical activity levels both during the commute and outside of the commute. While the study does not establish causality, the results provide some support for the notion that policy makers interested in increasing physical activity levels should consider changing not only the physical environment, but also perceived neighborhood characteristics and travel attitudes.

  3. Exploring the Influence of Attitudes to Walking and Cycling on Commute Mode Choice Using a Hybrid Choice Model

    Directory of Open Access Journals (Sweden)

    Chuan Ding

    2017-01-01

    Full Text Available Transport-related problems, such as automobile dependence, traffic congestion, and greenhouse emissions, lead to a great burden on the environment. In developing countries like China, in order to improve the air quality, promoting sustainable travel modes to reduce the automobile usage is gradually recognized as an emerging national concern. Though there are many studies related to the physically active modes (e.g., walking and cycling, the research on the influence of attitudes to active modes on travel behavior is limited, especially in China. To fill up this gap, this paper focuses on examining the impact of attitudes to walking and cycling on commute mode choice. Using the survey data collected in China cities, an integrated discrete choice model and the structural equation model are proposed. By applying the hybrid choice model, not only the role of the latent attitude played in travel mode choice, but also the indirect effects of social factors on travel mode choice are obtained. The comparison indicates that the hybrid choice model outperforms the traditional model. This study is expected to provide a better understanding for urban planners on the influential factors of green travel modes.

  4. Analysis of Urban Car Owners Commute Mode Choice Based on Evolutionary Game Model

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    Huawei Gong

    2015-01-01

    Full Text Available With the aggravation of the traffic congestion in the city, car owners will have to give up commuting with private cars and take the public transportation instead. The paper uses the replication dynamic mechanism to simulate the learning and adjustment mechanism of the automobile owners commuting mode selection. The evolutionary stable strategy is used to describe the long-term evolution of competition game trend. Finally we simulate equilibrium and stability of an evolution of the game under a payoff imbalance situation. The research shows that a certain proportion of car owners will choose public transit under the pressure of public transport development and heavy traffic, and the proportion will be closely related to the initial conditions and urban transportation development policy.

  5. Discrete choice models for commuting interactions

    DEFF Research Database (Denmark)

    Rouwendal, Jan; Mulalic, Ismir; Levkovich, Or

    An emerging quantitative spatial economics literature models commuting interactions by a gravity equation that is mathematically equivalent to a multinomial logit model. This model is widely viewed as restrictive because of the independence of irrelevant alternatives (IIA) property that links...... substitution behavior in response to changes in the attractiveness of choice alternatives to choice probabilities in a mechanistic way. This is relevant for counterfactual analysis. In this paper we examine the appropriateness of the commuting model from a theoretical as well as an empirical point of view. We...... show that conventional specification tests of the multinomial logit model are of limited use when alternative specific constants are used, as is common in the recent literature, and offer no information with respect to the validity of IIA. In articular, we show that maximum likelihood estimation...

  6. Commuting and wellbeing in London: The roles of commute mode and local public transport connectivity.

    Science.gov (United States)

    Chng, Samuel; White, Mathew; Abraham, Charles; Skippon, Stephen

    2016-07-01

    To explore the relationships between commute mode, neighbourhood public transport connectivity and subjective wellbeing. The study used data on 3630 commuters in London from wave two of Understanding Society (2010/11). Multivariate linear regressions were used to investigate how commute mode and neighbourhood public transport connectivity were associated with subjective wellbeing for all London commuters and for public transport commuters only. Subjective wellbeing was operationalized in terms of both a positive expression (life satisfaction measured by a global single-item question) and a more negative expression (mental distress measured by the General Health Questionnaire). Logistic regression was also used to explore the predictors of public transport over non-public transport commutes. After accounting for potentially-confounding area-level and individual-level socioeconomic and commute-related variables, only walking commutes (but not other modes) were associated with significantly higher life satisfaction than car use but not with lower mental distress, compared to driving. While better public transport connectivity was associated with significantly lower mental distress in general, train users with better connectivity had higher levels of mental distress. Moreover, connectivity was unrelated to likelihood of using public transport for commuting. Instead, public transport commutes were more likely amongst younger commuters who made longer distance commutes and had comparatively fewer children and cars within the household. The findings highlight the heterogeneity of relationships between commute mode, public transport connectivity and subjective wellbeing and have implications for intervention strategies and policies designed to promote commuting behaviour change. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Effect of a School Choice Policy Change on Active Commuting to Elementary School.

    Science.gov (United States)

    Sirard, John R; McDonald, Kelsey; Mustain, Patrick; Hogan, Whitney; Helm, Alison

    2015-01-01

    The purposes of this study were to assess the effect of restricting school choice on changes in travel distance to school and transportation mode for elementary school students. Study design was pre-post (spring 2010-fall 2010) quasi-experimental. Study setting was all public elementary schools in Minneapolis, Minnesota. Subjects comprised approximately 20,500 students across 39 schools. Study assessed a school choice policy change that restricted school choice to a school closer to the family's home. School district transportation data were used to determine distance to school. Direct observations of student travel modes (two morning and two afternoon commutes at each time point) were used to assess transportation mode. Chi-square and independent-sample t-tests were calculated to describe the schools. Repeated measures general linear models were used to assess changes in travel distance to school and observed commuting behavior. Distance to school significantly decreased (1.83 ± .48 miles to 1.74 ± .46 miles; p = .002). We failed to observe any significant changes in morning (+.7%) or afternoon (-.7%) active commuting (both p = .08) or the number of automobiles in the morning (-7 autos per school; p = .06) or afternoon (+3 autos per school; p = .14). The more restrictive school choice policy decreased distance to school but had no significant effect on active commuting. Policy interventions designed to increase active commuting to school may require additional time to gain traction and programmatic support to induce changes in behavior.

  8. The effectiveness of ridesharing incentives; Discrete-choice models of commuting in Southern California

    Energy Technology Data Exchange (ETDEWEB)

    Brownstone, D.; Golob, T.F. (California Univ., Irvine, CA (USA))

    1992-03-01

    The effects of certain incentives designed to promote ridesharing on work trips to reduce congestion and air pollution are studies. Ordered probit discrete choice models of commuters' mode choices (always rideshare, sometimes rideshare, and always drive alone) are estimated using a new study of full-time workers' commuting behavior in the greater Los Angeles area. We find that women and those who have larger households with multiple workers, longer commutes, and larger worksites are more likely to rideshare. Partial equilibrium policy simulations with our model indicate that providing all workers with reserved parking, ridesharing subsidies, guaranteed rides home, and high-occupancy vehicle lanes would reduce drive-alone commuting between 11 and 18 percent. 1 app., 6 tabs., 22 refs.

  9. Route Choice Model Based on Game Theory for Commuters

    Directory of Open Access Journals (Sweden)

    Licai Yang

    2016-06-01

    Full Text Available The traffic behaviours of commuters may cause traffic congestion during peak hours. Advanced Traffic Information System can provide dynamic information to travellers. Due to the lack of timeliness and comprehensiveness, the provided information cannot satisfy the travellers’ needs. Since the assumptions of traditional route choice model based on Expected Utility Theory conflict with the actual situation, a route choice model based on Game Theory is proposed to provide reliable route choice to commuters in actual situation in this paper. The proposed model treats the alternative routes as game players and utilizes the precision of predicted information and familiarity of traffic condition to build a game. The optimal route can be generated considering Nash Equilibrium by solving the route choice game. Simulations and experimental analysis show that the proposed model can describe the commuters’ routine route choice decisionexactly and the provided route is reliable.

  10. Mode choice model parameters estimation

    OpenAIRE

    Strnad, Irena

    2010-01-01

    The present work focuses on parameter estimation of two mode choice models: multinomial logit and EVA 2 model, where four different modes and five different trip purposes are taken into account. Mode choice model discusses the behavioral aspect of mode choice making and enables its application to a traffic model. Mode choice model includes mode choice affecting trip factors by using each mode and their relative importance to choice made. When trip factor values are known, it...

  11. Transport priorities, risk perception and worry associated with mode use and preferences among Norwegian commuters.

    Science.gov (United States)

    Nordfjærn, Trond; Simşekoğlu, Özlem; Lind, Hans Brende; Jørgensen, Stig Halvard; Rundmo, Torbjørn

    2014-11-01

    There is currently scant research on the role of transport priorities, risk perception and worry for travel mode use and preferences. The present study aims to examine these factors in relation to mode use and preferences among Norwegian commuters. A web-based survey was conducted in a randomly obtained representative sample of daily commuters in the extended greater Oslo area (n=690). The results showed that those who prioritized efficiency and flexibility tended to commute by car, while those who prioritized safety and comfort used public (e.g. metro, tram, and train) or active (e.g. walking and cycling) transport. In a free choice scenario, the respondents who prioritized flexibility reported a preference for using a car, whereas those who prioritized safety and comfort preferred public and active transport for their commuter travels. Risk perception of high impact events, such as terrorism and major accidents, as well as risk perception related to personal impact risks (theft, violence etc.) were related to car use on commuter travels. Transport-related worry exerted weak influences on mode use and preferences. Increased speed on rail transport and more frequent departures may be effective in reducing car use on commuter travels. Risk communication should focus on highlighting the low risk of experiencing security and safety issues in the public transport sector, and this message should be complemented by efforts to reduce the probability of negative events affecting public transport. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Features of Synchronous Electronically Commutated Motors in Servomotor Operation Modes

    Science.gov (United States)

    Dirba, J.; Lavrinovicha, L.; Dobriyan, R.

    2017-04-01

    The authors consider the features and operation specifics of the synchronous permanent magnet motors and the synchronous reluctance motors with electronic commutation in servomotor operation modes. Calculation results show that mechanical and control characteristics of studied motors are close to a linear shape. The studied motor control is proposed to implement similar to phase control of induction servomotor; it means that angle θ (angle between vectors of the supply voltage and non-load electromotive force) or angle ɛ (angle between rotor direct axis and armature magnetomotive force axis) is changed. The analysis results show that synchronous electronically commutated motors could be used as servomotors.

  13. Analyzing multiday route choice behavior of commuters using GPS data

    Directory of Open Access Journals (Sweden)

    Wenyun Tang

    2016-02-01

    Full Text Available In this study, accurate global position system and geographic information system data were employed to reveal multiday routes people used and to study multiday route choice behavior for the same origin–destination trips, from home to work. A new way of thinking about route choice modeling is provided in this study. Travelers are classified into three kinds based on the deviation between actual routes and the shortest travel time paths. Based on the classification, a two-stage route choice process is proposed, in which the first step is to classify the travelers and the second one is to model route choice behavior. After analyzing the characteristics of different types of travelers, an artificial neural network was adopted to classify travelers and model route choice behavior. An empirical study using global position systems data collected in Minneapolis–St Paul metropolitan area was carried out. It finds that most travelers follow the same route during commute trips on successive days. And different types of travelers have a significant difference in route choice property. The modeling results indicate that neural network framework can classify travelers and model route choice well.

  14. The Fort Collins Commuter Study: Impact of route type and transport mode on personal exposure to multiple air pollutants

    OpenAIRE

    Good, Nicholas; M?lter, Anna; Ackerson, Charis; Bachand, Annette; Carpenter, Taylor; Clark, Maggie L; Fedak, Kristen M; Kayne, Ashleigh; Koehler, Kirsten; Moore, Brianna; L'Orange, Christian; Quinn, Casey; Ugave, Viney; Stuart, Amy L; Peel, Jennifer L

    2015-01-01

    Traffic-related air pollution is associated with increased mortality and morbidity, yet few studies have examined strategies to reduce individual exposure while commuting. The present study aimed to quantify how choice of mode and route type affects personal exposure to air pollutants during commuting. We analyzed within-person difference in exposures to multiple air pollutants (black carbon (BC), carbon monoxide (CO), ultrafine particle number concentration (PNC), and fine particulate matter...

  15. Impact of Distance on Mode of Active Commuting in Chilean Children and Adolescents

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    Fernando Rodríguez-Rodríguez

    2017-11-01

    Full Text Available Active commuting could contribute to increasing physical activity. The objective of this study was to characterise patterns of active commuting to and from schools in children and adolescents in Chile. A total of 453 Chilean children and adolescents aged between 10 and 18 years were included in this study. Data regarding modes of commuting and commuting distance was collected using a validated questionnaire. Commuting mode was classified as active commuting (walking and/or cycling or non-active commuting (car, motorcycle and/or bus. Commuting distance expressed in kilometres was categorised into six subgroups (0 to 0.5, 0.6 to 1, 1.1 to 2, 2.1 to 3, 3.1 to 5 and >5 km. Car commuting was the main mode for children (to school 64.9%; from school 51.2% and adolescents (to school 50.2%; from school 24.7%. Whereas public bus commuting was the main transport used by adolescents to return from school. Only 11.0% and 24.8% of children and adolescents, respectively, walk to school. The proportion of children and adolescents who engage in active commuting was lower in those covering longer distances compared to a short distance. Adolescents walked to and from school more frequently than children. These findings show that non-active commuting was the most common mode of transport and that journey distances may influence commuting modes in children and adolescents.

  16. From sedentary to active school commute: Multi-level factors associated with travel mode shifts.

    Science.gov (United States)

    Lee, Chanam; Yoon, Jeongjae; Zhu, Xuemei

    2017-02-01

    Previous research has examined personal, social, and environmental correlates of active commuting to school, but most were cross-sectional and mode choice studies. This exploratory case study utilized a retrospective natural experiment opportunity, where a group of students transferred to a new school, and therefore experienced changes in their home-to-school travel environments. It examined whether such changes led to mode shifts from sedentary (car or school bus) to active (walking and bicycling) and what factors were associated with those shifts. Retrospective parental survey data (n=165, response rate=46%) were collected in 2011 from a new elementary school that opened in 2010 in Austin, Texas. The survey asked about the child's school travel mode and parental perceptions of home-to-school travel environments before and after the transfer, as well as personal and social factors. Multivariate logistic regressions were used to predict the odds of shifting from sedentary to active modes, using personal, social, and physical environmental variables. Sixty-eight (41.2%) respondents reported a sedentary-to-active mode shift for school commuting. Such shifts were associated with changes in school travel environments (e.g., shorter travel distance, improved safety, and decreased availability of bike lanes/paths) and relevant programs/services (e.g., increase in walking-promotion programs, and decrease in school bus service due to shortened distances). Targeting the current sedentary mode users is important to bring health benefits through increased physical activity and environmental benefits from reduced automobile use. Sedentary-to-active mode shifts may be encouraged by providing walking-promotion programs and by reducing travel distances and safety threats en route to school. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Private and public modes of bicycle commuting: a perspective on attitude and perception.

    Science.gov (United States)

    Curto, A; de Nazelle, A; Donaire-Gonzalez, D; Cole-Hunter, T; Garcia-Aymerich, J; Martínez, D; Anaya, E; Rodríguez, D; Jerrett, M; Nieuwenhuijsen, M J

    2016-08-01

    Public bicycle-sharing initiatives can act as health enhancement strategies among urban populations. The aim of the study was to determine which attitudes and perceptions of behavioural control toward cycling and a bicycle-sharing system distinguish commuters with a different adherence to bicycle commuting.  The recruitment process was conducted in 40 random points in Barcelona from 2011 to 2012. Subjects completed a telephone-based questionnaire including 27 attitude and perception statements. Based on their most common one-way commute trip and willingness to commute by bicycle, subjects were classified into Private Bicycle (PB), public bicycle or Bicing Bicycle (BB), Willing Non-bicycle (WN) and Non-willing Non-bicycle (NN) commuters. After reducing the survey statements through principal component analysis, a multinomial logistic regression model was obtained to evaluate associations between attitudinal and commuter sub-groups.  We included 814 adults in the analysis [51.6% female, mean (SD): age 36.6 (10.3) years]. BB commuters were 2.0 times [95% confidence interval (CI) = 1.1-3.7] less likely to perceive bicycle as a quick, flexible and enjoyable mode compared to PB. BB, WN and NN were 2.5 (95% CI = 1.46-4.24), 2.6 (95% CI = 1.53-4.41) and 2.3 times (95% CI = 1.30-4.10) more likely to perceive benefits of using public bicycles (bicycle maintenance and parking avoidance, low cost and no worries about theft and vandalism) than did PB.  Willing non-bicycle and public-bicycle commuters had more favourable perception toward public-shared bicycles compared to private cyclists. Hence, public bicycles may be the impetus for those willing to start bicycle commuting, thereby increasing physical activity levels. © The Author 2016. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  18. Commuter exposure to particulate matter in public transportation modes in Hong Kong

    Science.gov (United States)

    Chan, L. Y.; Lau, W. L.; Lee, S. C.; Chan, C. Y.

    This study examined commuter's exposure to respirable suspended particulate matters while commuting in public transportation modes. The survey was conducted between October 1999 and January 2000 in Hong Kong. A total of eight public transportation modes, that are bus, tram, public light bus, taxi, ferry, Kowloon-Canton Railway, Mass Transit Railway and Light Rail Transit, were selected in the study. They were grouped into four categories: (T1) railway transport; (T2) non-air-conditioned roadway transport; (T3) air-conditioned roadway transport and (T4) marine transport. Both PM 10 and PM 2.5 levels were investigated. The results indicate that the particulate level is greatly affected by the mode of transport as well as the ventilation system of the transport. The overall average PM 10 concentration level in T2 (147 μg m -3) is the highest and is followed by T4 (81 μg m -3) and T3 (65 μg m -3). The PM 10 level in T1 (50 μg m -3) is the lowest. Notably, the commuter exposure in tram (175 μg m -3) is the highest among all the monitored commuting modes. Commuting modes such as railway and air-conditioned vehicle are recommended as a substitute for non-air-conditioned vehicle. The PM 2.5 to PM 10 ratio in transports ranged from 63% to 78%. Higher PM 2.5 to PM 10 ratio is found in vehicles with air-conditioning system. For the double deck vehicle, higher PM 10 level has resulted in the lower deck. The average upper-deck to lower-deck PM 10 ratio is 0.836, 0.751 and 0.738 in air-conditioned bus, non-air-conditioned bus and non-air-conditioned tram, respectively. Typical concentration profiles in different transports are also presented.

  19. A travel mode comparison of commuters' exposures to air pollutants in Barcelona

    Science.gov (United States)

    de Nazelle, Audrey; Fruin, Scott; Westerdahl, Dane; Martinez, David; Ripoll, Anna; Kubesch, Nadine; Nieuwenhuijsen, Mark

    2012-11-01

    Daily commutes may contribute disproportionately to overall daily inhalations of urban air contaminants. Understanding factors that explain variability of exposures during travel, and especially differences across transportation modes, is essential to accurately assess health impacts of traffic emissions and to develop effective mitigating measures. We evaluated exposures and inhaled doses of air pollution and assessed factors that contributed to their variability in different travel modes in Barcelona. Black carbon (BC), ultrafine particles (UFP), carbon monoxide (CO), fine particle mass (PM2.5) and carbon dioxide (CO2) were measured and compared across walk, bike, bus, and car modes for a total of 172 trips made on two different round trip routes. On average, the car mode experienced highest concentrations for all contaminants. In pairwise t-tests between concurrent mode runs, statistically significant differences were found for cars compared to walking and biking. Car-to-walk or car-to-bike concentration ratios ranged from 1.3 for CO2 to 25 for CO and were 2-3 for PM2.5, BC, and UFP. In multivariate analyses, travel mode explained the greatest variability in travel exposures, from 8% for PM2.5 to 70% for CO. Different modal patterns emerged when estimating daily inhaled dose, with active commuters' two to three times greater total inhalation volume during travel producing about equal UFP and BC daily inhaled doses to car commuters and 33-50% higher UFP and BC doses compared to bus commuters. These findings, however, are specific to the bike and pedestrian lanes in this study being immediately adjacent to the roadways measured. Dedicated bike or pedestrian routes away from traffic would lead to lower active travel doses.

  20. Quasi-normal modes from non-commutative matrix dynamics

    Science.gov (United States)

    Aprile, Francesco; Sanfilippo, Francesco

    2017-09-01

    We explore similarities between the process of relaxation in the BMN matrix model and the physics of black holes in AdS/CFT. Focusing on Dyson-fluid solutions of the matrix model, we perform numerical simulations of the real time dynamics of the system. By quenching the equilibrium distribution we study quasi-normal oscillations of scalar single trace observables, we isolate the lowest quasi-normal mode, and we determine its frequencies as function of the energy. Considering the BMN matrix model as a truncation of N=4 SYM, we also compute the frequencies of the quasi-normal modes of the dual scalar fields in the AdS5-Schwarzschild background. We compare the results, and we finda surprising similarity.

  1. EnviroAtlas - Commute Modes and Working from Home by Block Group for the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset portrays the percent of workers who commute to work using various modes, and the percent who work from home within each Census Block Group...

  2. Test-retest reliability of a new self reported comprehensive questionnaire measuring frequencies of different modes of adolescents commuting to school and their parents commuting to work - the ATN questionnaire

    Directory of Open Access Journals (Sweden)

    Bjørkelund Line A

    2009-10-01

    Full Text Available Abstract Background Studies assessing active commuting to school usually use simple questionnaires, and often is mode of commuting reported with a single questionnaire item only. The purpose of the present study is to report the test-retest reliability of a newly developed comprehensive questionnaire on active commuting to school and work among 6th grade school children and their parents in Norway. Methods A total of 106 pupils and 77 parents completed a questionnaire two times, 14 days apart. The questionnaire consisted of frequency items on how often the participants walk, cycle, go by car and go by public transportation to school (pupils or work (parents. The questionnaire was divided into seasons and to/from school or work in order to cover seasonal and topographic variations. The average number of trips for each mode of commuting was calculated. Then the sample was categorised into mode of commuting: walkers, cyclists, car commuters or public transport commuters. Results The average numbers of trips did not differ for any of the commuting modes comparing test to retest data for any of the seasons. Test-retest correlation coefficients were high for all modes of commuting (Spearman correlation coefficient were 0.85-0.92 for pupils and 0.82-0.95 for parents. Most participants categorised into mode of commuting were categorized into the same mode at both time points (97% and 95% for pupils and parents respectively. Conclusion This newly developed questionnaire appears to be a reliable tool for measuring active commuting to school and work.

  3. Effects of commuting mode on air pollution exposure and cardiovascular health among young adults in Taipei, Taiwan.

    Science.gov (United States)

    Liu, Wen-Te; Ma, Chih-Ming; Liu, I-Jung; Han, Bor-Cheng; Chuang, Hsiao-Chi; Chuang, Kai-Jen

    2015-05-01

    The association between traffic-related air pollution and adverse cardiovascular effects has been well documented; however, little is known about whether different commuting modes can modify the effects of air pollution on the cardiovascular system in human subjects in urban areas with heavy traffic. We recruited 120 young, healthy subjects in Taipei, Taiwan. Each participant was classified with different commuting modes according to his/her own commuting style. Three repeated measurements of heart rate variability (HRV) indices {standard deviation of NN intervals (SDNN) and the square root of the mean of the sum of the squares of differences between adjacent NN intervals (r-MSSD)}, particulate matter with an aerodynamic diameter ≤ 2.5 μm (PM2.5), temperature, humidity and noise level were conducted for each subject during 1-h morning commutes (0900-1000 h) in four different commuting modes, including an electrically powered subway, a gas-powered bus, a gasoline-powered car, and walking. Linear mixed-effects models were used to investigate the association of PM2.5 with HRV indices. The results showed that decreases in the HRV indices were associated with increased levels of PM2.5. The personal exposure levels to PM2.5 were the highest in the walking mode. The effects of PM2.5 on cardiovascular endpoints were the lowest in the subway mode compared to the effects in the walking mode. The participants in the car and bus modes had reduced effects on their cardiovascular endpoints compared to the participants in the walking mode. We concluded that traffic-related PM2.5 is associated with autonomic alteration. Commuting modes can modify the effects of PM2.5 on HRV indices among young, healthy subjects. Copyright © 2015 Elsevier GmbH. All rights reserved.

  4. Transportation Mode Choice Analysis Based on Classification Methods

    OpenAIRE

    Zeņina, N; Borisovs, A.

    2011-01-01

    Mode choice analysis has received the most attention among discrete choice problems in travel behavior literature. Most traditional mode choice models are based on the principle of random utility maximization derived from econometric theory. This paper investigates performance of mode choice analysis with classification methods - decision trees, discriminant analysis and multinomial logit. Experimental results have demonstrated satisfactory quality of classification.

  5. Commuter exposure to aromatic VOCs in public transportation modes in Hong Kong.

    Science.gov (United States)

    Lau, Wai-Lun; Chan, Lo-Yin

    2003-06-01

    This study investigated commuter exposure to aromatic volatile organic compounds (VOCs) in different commuting microenvironments. In Hong Kong, more than 90% of the local citizens rely on public transport facilities in their daily commutes. During five winter months in late 2001 and early 2002, in-vehicle monitoring was performed in nine popular public transportation modes: tram, public light bus, air-conditioned bus, non-air-conditioned bus, taxi, ferry and three railway systems (Mass Transit Railway-MTR, Kowloon-Canton Railway-KCR and Light Rail Transit-LRT). These transports were grouped into three categories: railway transport, roadway transport and marine transport. Air samples of benzene, toluene, ethylbenzene and m/p/o-xylene were collected by canisters and analysed by gas chromatography and mass selective detector technique. Results indicated that the in-vehicle VOC exposure levels were greatly influenced by the mode of transport. For benzene, mean concentration ranged from 4.8 to 6.1 microg x m(-3) in roadway transports, 3.0-3.8 microg x m(-3) in railway transports and it was 2.1 microg x m(-3) in ferry. Regardless of the results in MTR and air-conditioned buses, the VOC levels in roadway transport were the highest and was followed by railway transport. The exposure levels in marine transport were the lowest. The TEX concentrations were found to be substantially higher in air-conditioned buses and MTR trains than in other transports, suggesting the existence of additional solvent-related sources in their vehicle interiors. Measurements in non-air-conditioned double deck vehicles indicate that there was slightly higher VOC levels in the lower deck than in the upper deck microenvironment. The average upper to lower deck exposure ratio ranged from 0.79 to 0.87 in trams and 0.78-0.83 in non-air-conditioned buses, depending on the compound of concern. The VOC exposure levels of public transport commuters in Hong Kong are far lower than those in most oversea

  6. Context Dependent Stated Choice Experiments : The Case of Train Egress Mode Choice

    NARCIS (Netherlands)

    Molin, E.J.E.; Timmermans, H.J.P.

    2010-01-01

    Based on the contention that the influence of context on mode choices made in multi-modal trip chains is under-researched, this paper discusses the design and results of a stated choice experiment to estimate the effects of context variables on train egress mode choice: the mode chosen after a train

  7. Personal exposure to fine particulate air pollution while commuting: An examination of six transport modes on an urban arterial roadway.

    Science.gov (United States)

    Chaney, Robert A; Sloan, Chantel D; Cooper, Victoria C; Robinson, Daniel R; Hendrickson, Nathan R; McCord, Tyler A; Johnston, James D

    2017-01-01

    Traffic-related air pollution in urban areas contributes significantly to commuters' daily PM2.5 exposures, but varies widely depending on mode of commuting. To date, studies show conflicting results for PM2.5 exposures based on mode of commuting, and few studies compare multiple modes of transportation simultaneously along a common route, making inter-modal comparisons difficult. In this study, we examined breathing zone PM2.5 exposures for six different modes of commuting (bicycle, walking, driving with windows open and closed, bus, and light-rail train) simultaneously on a single 2.7 km (1.68 mile) arterial urban route in Salt Lake City, Utah (USA) during peak "rush hour" times. Using previously published minute ventilation rates, we estimated the inhaled dose and exposure rate for each mode of commuting. Mean PM2.5 concentrations ranged from 5.20 μg/m3 for driving with windows closed to 15.21 μg/m3 for driving with windows open. The estimated inhaled doses over the 2.7 km route were 6.83 μg for walking, 2.78 μg for cycling, 1.28 μg for light-rail train, 1.24 μg for driving with windows open, 1.23 μg for bus, and 0.32 μg for driving with windows closed. Similarly, the exposure rates were highest for cycling (18.0 μg/hr) and walking (16.8 μg/hr), and lowest for driving with windows closed (3.7 μg/hr). Our findings support previous studies showing that active commuters receive a greater PM2.5 dose and have higher rates of exposure than commuters using automobiles or public transportation. Our findings also support previous studies showing that driving with windows closed is protective against traffic-related PM2.5 exposure.

  8. Personal exposure to fine particulate air pollution while commuting: An examination of six transport modes on an urban arterial roadway.

    Directory of Open Access Journals (Sweden)

    Robert A Chaney

    Full Text Available Traffic-related air pollution in urban areas contributes significantly to commuters' daily PM2.5 exposures, but varies widely depending on mode of commuting. To date, studies show conflicting results for PM2.5 exposures based on mode of commuting, and few studies compare multiple modes of transportation simultaneously along a common route, making inter-modal comparisons difficult. In this study, we examined breathing zone PM2.5 exposures for six different modes of commuting (bicycle, walking, driving with windows open and closed, bus, and light-rail train simultaneously on a single 2.7 km (1.68 mile arterial urban route in Salt Lake City, Utah (USA during peak "rush hour" times. Using previously published minute ventilation rates, we estimated the inhaled dose and exposure rate for each mode of commuting. Mean PM2.5 concentrations ranged from 5.20 μg/m3 for driving with windows closed to 15.21 μg/m3 for driving with windows open. The estimated inhaled doses over the 2.7 km route were 6.83 μg for walking, 2.78 μg for cycling, 1.28 μg for light-rail train, 1.24 μg for driving with windows open, 1.23 μg for bus, and 0.32 μg for driving with windows closed. Similarly, the exposure rates were highest for cycling (18.0 μg/hr and walking (16.8 μg/hr, and lowest for driving with windows closed (3.7 μg/hr. Our findings support previous studies showing that active commuters receive a greater PM2.5 dose and have higher rates of exposure than commuters using automobiles or public transportation. Our findings also support previous studies showing that driving with windows closed is protective against traffic-related PM2.5 exposure.

  9. Foreign direct investment mode choice : entry and establishment modes in transition economies

    NARCIS (Netherlands)

    Dikova, Desislava; van Witteloostuijn, Arien

    2007-01-01

    In this study, we bridge two streams of foreign direct investment literature, specifically studies on establishment mode choice (i.e., the choice between an acquisition and a greenfield establishment) and studies on entry mode choice (i.e., the choice between a wholly owned outlet and a subsidiary

  10. Private and public modes of bicycle commuting: a perspective on attitude and perception.

    OpenAIRE

    Curto, A.; De Nazelle, A.; Donaire-Gonzalez, D; Cole-Hunter, T; Garcia-Aymerich, J.; Mart?nez, D; Anaya, E.; Rodr?guez, D; Jerrett, M.; Nieuwenhuijsen, MJ

    2016-01-01

    BACKGROUND: Public bicycle-sharing initiatives can act as health enhancement strategies among urban populations. The aim of the study was to determine which attitudes and perceptions of behavioural control toward cycling and a bicycle-sharing system distinguish commuters with a different adherence to bicycle commuting.? METHODS: The recruitment process was conducted in 40 random points in Barcelona from 2011 to 2012. Subjects completed a telephone-based questionnaire including 27 attitude and...

  11. How Important Is Study Mode in Student University Choice?

    Science.gov (United States)

    Hagel, Pauline; Shaw, Robin N.

    2010-01-01

    Conjoint analysis was used to model the importance of study mode in students' choice of university. Study mode was proposed as a key choice attribute as universities have diversified their means of delivering education and increased the use of online delivery. Results are reported for two conjoint experiments. The first investigated how…

  12. Mode choice endogeneity in value of travel time estimation

    DEFF Research Database (Denmark)

    Mabit, Stefan Lindhard; Fosgerau, Mogens

    The current way to estimate value of travel time is to use a mode-specific sample and hence to estimate mode-specific value of travel times. This approach raises certain questions concerning how to generalise the values to a population. A problem would be if there is an uncontrolled sample...... selection mechanism. This is the case if there is correlation between mode choice and the value of travel time that is not controlled for by explanatory variables. What could confuse the estimated values is the difficulty to separate mode effects from user effect. An example would be the effect of income...... of travel time we use a stated choice dataset. These data include binary choice within mode for car and bus. The first approach is to use a probit model to model mode choice using instruments and then use this in the estimation of the value of travel time. The second approach is based on the use of a very...

  13. Digital Implementation of Method for Discontinuous Current Mode Compensation Of High-Performance Line-Commutated Converters

    CERN Document Server

    Maestri, S; Uicich, G; Gomez Costa, J; Petrocelli, R; CERN. Geneva. TE Department

    2010-01-01

    Many high-performance power converters at CERN are implemented with thyristors, mostly in CCM (Continuous Conduction Mode) due to their better dynamic response. In DCM (Discontinuous Conduction Mode), the converter reduces its small-signal gain, producing a degraded time response which can lead to instability. Several of these converters use digital regulation, allowing the implementation of complex non- linear control techniques. Therefore, a strategy to control the converters in DCM (Discontinuous Conduction Mode) can be implemented, bearing in mind that their standard operation (sampling time, measured signals, acquisition system) can not be drastically changed. This report presents the implementation of a new method to control line-commutated converters in discontinuous conduction mode (DCM). The method is based on the modfication of the thyristor's ring angle _ using a linear approximation, yielding nearly the same dynamic performance as in continuous conduction mode. The _ring angle is corrected by addi...

  14. Commuter migration: work environment factors influencing nurses' decisions regarding choice of employment.

    Science.gov (United States)

    Rajacich, D; Freeman, M; Armstrong-Stassen, M; Cameron, S; Wolfe, B

    2014-06-01

    Nurse migration is of global concern for every country, and study of migration can provide critical information for managers concerned with nurse recruitment and retention. This mixed-methods research examined factors influencing registered nurses' (RNs') decisions to work in their home country, Canada, or to commute daily to a nursing position in the United States. Measures included nurses' feelings about their work environment conditions, work status congruence (the goodness of fit between employer expectations and their own regarding hours and times worked), professional development opportunities, and their perceptions of organizational support and autonomy (freedom and independence) in the workplace. All work environment variables were significantly higher for nurses working in Michigan. Qualitative results supported these survey findings, providing additional information about nurses' satisfaction. Nurses in our sample were more satisfied with all the work environment factors examined, even when stress from commuting out of country was experienced. The environmental issues examined in this study should be considered by nurse managers concerned with recruitment and retention of nurses. Copyright © 2014 Longwoods Publishing.

  15. Some issues of passenger choice of suburban transport mode

    Directory of Open Access Journals (Sweden)

    Тetyana М. Grigorova

    2015-06-01

    Full Text Available In this article the passenger choice of transport mode for moving to suburban is discussed. The analysis of methods of Transport Management in suburban transportation showed that they did not fully take into account the effect of the transport process parameters on the passenger choice of transport mode for travel. The aim of research is to determine the value of the factors that influence passenger choice of suburban transport. The study was conducted on the basis of passenger survey on the factors affecting the choice of transport mode, and the importance of these factors. Kendall's coefficient of concordance its statistical significance were used to evaluate the consistency of expert opinion. The main factors for choosing the mode of suburban transport are identified. The identified factors can then be used in determining selection patterns of suburban transport mode.

  16. Adaptive stated choice experiment for access and egress mode choice to train stations

    NARCIS (Netherlands)

    La Paix Puello, Lissy Cesarina; Geurs, Karst Teunis

    2014-01-01

    This paper presents an analysis of an adaptive stated choice experiment in the Netherlands to quantify the influence of different factors in the access and egress mode choice to railway stations. For this purpose a sample of 1524 respondents was collected. Mixed logit choice models are estimated

  17. Modelling the joint access mode and railway station choice

    NARCIS (Netherlands)

    Debrezion, G.; Pels, E.; Rietveld, P.

    2008-01-01

    This study models the choices of Dutch railway users. We find a steeper negative distance effect on the utility of departure stations accessed by the non-motorized modes of walking and bicycle as compared to the motorized modes of car and public transport. Availability of parking places and bicycle

  18. Commuter exposure to PM2.5, BC, and UFP in six common transport microenvironments in Sacramento, California

    Science.gov (United States)

    Ham, Walter; Vijayan, Abhilash; Schulte, Nico; Herner, Jorn D.

    2017-10-01

    This study was designed to estimate and compare the air pollution exposures experienced by commuters in six common transportation modes utilized by California residents, and to evaluate the impact of practical exposure mitigation strategies in reducing commute exposures. We measured concentrations of fine particle matter (PM2.5), black carbon (BC), and ultrafine particles (UFP) for 161 commutes between April 2014 and November 2015 in Sacramento, CA. We collected measurements for six modes including single occupancy vehicles, high occupancy vehicles (multiple occupants), buses, light rail, train, and bicycling. The largest average concentrations for most pollutants were measured during train commutes and the lowest average concentrations were observed during light-rail commutes. Mitigation options were explored for personal vehicles, bicycling, and train commute modes. We found that ventilation settings of personal vehicles can reduce in-vehicle PM2.5, BC, and UFP concentrations by up to 75%. Similarly, bicycle route choice can reduce exposures by 15-75% with the lowest concentrations observed during commutes on dedicated bicycle paths away from traffic sources. Train commuters experienced UFP concentrations an order of magnitude greater when the locomotive engine was pulling the rail cars versus pushing the rail cars. We found that UFP concentrations during bus, bicycling, and train commutes were 1.6-5.3 times greater than personal vehicle commutes, while light rail commutes had 30% lower UFP concentrations than personal vehicle commutes. The largest exposure per mile occurred during bicycle commutes with PM2.5, BC, and UFP exposures of 1.312 μg/mile, 0.097 μg/mile, and 3.0 × 109 particles/mile, respectively. Train commutes experienced the largest exposure per mile of all of the combustion-derived transportation commute modes. BC accounted for 5-20% of total PM mass across all commute modes with an average fraction of ∼7% of PM2.5.

  19. The choice of foreign entry modes in a control perspective

    DEFF Research Database (Denmark)

    Boyd, Britta; Dyhr Ulrich, Anna Marie; Hollensen, Svend

    depending on the control that the company has over its activities abroad. The paper examines selected factors that influence the ‘entry modes’ of Danish SMEs in different strategic settings. Results show that the most deciding factor for the choice of high control entry mode (subsidiary) was the factor...... turnover. The factors: personal networks and the interruption of the international activities were the most significant factors for the choice of intermediate mode (joint ventures and strategic alliances).......The aim of this article is to investigate the choice of entry modes for international markets in a control perspective. A survey from The Confederation of Danish Industry with 234 Danish small- and medium sized enterprises served as a data base. The entry modes are categorized into three groups...

  20. Evolution Game Model of Travel Mode Choice in Metropolitan

    Directory of Open Access Journals (Sweden)

    Chaoqun Wu

    2015-01-01

    Full Text Available The paper describes an evolution game model of travel mode choice to determine whether transportation policies would have the desired effect. The model is first expressed as a two-stage sequential game in the extensive form based on the similarity between evolution game theory and the travel mode choice process. Second, backward induction is used to solve for Nash equilibrium of the game based on the Folk Theorem. Third, the sensitivity analysis suggests that a payoff reduction of travel by any mode will result in a rising proportion of inhabitants travelling by that mode and falling proportions of inhabitants travelling by other modes. Finally, the model is applied to Beijing inhabitants’ travel mode choices during morning peak hours and draws the conclusion that the proportion of inhabitants travelling by rail would increase when traffic congestion is more severe. This confirms that fast construction of the urban rail transit would be an effective means of alleviating traffic congestion. The model may be a useful tool for policy makers for analyzing the complex influence of travel mode choice processes on transport policies and transport construction projects.

  1. Forecasting the impact of transport improvements on commuting and residential choice

    NARCIS (Netherlands)

    Elhorst, J. Paul; Oosterhaven, Jan

    This paper develops a probabilistic, competing-destinations, assignment model that predicts changes in the spatial pattern of the working population as a result of transport improvements. The choice of residence is explained by a new non-parametric model, which represents an alternative to the

  2. Beyond distance: children's school travel mode choice.

    Science.gov (United States)

    Lee, Chanam; Zhu, Xuemei; Yoon, Jeongjae; Varni, James W

    2013-02-01

    Long distance is a leading environmental barrier to walking to school and requires long-term, multilevel interventions. Meanwhile, childhood obesity remains highly prevalent, calling for more immediate solutions. The purpose of this study was to examine attitudinal and environmental correlates of walking to the elementary school, controlling for distance. Using parental survey data, 601 child pairs with matched home locations and different school travel modes (walking vs. private automobile) were examined, using conditional logistic regressions. Despite the same/similar objectively measured distance and home location, perceptions of distance, sidewalk and traffic conditions, park presence, and convenience of walking differed between walkers and automobile users. Parental attitudes and children's preferences were associated with the odds of walking. Safety concerns (traffic danger, stranger danger, and getting lost) were higher among drivers, but only significant in bivariate analyses. To promote walking to school, route/street improvements appear promising, but parallel educational and promotional efforts may be needed to address perceptual and attitudinal barriers.

  3. Mode Choice Model for Public Transport with Categorized Latent Variables

    Directory of Open Access Journals (Sweden)

    Jian Chen

    2017-01-01

    Full Text Available Mode choice model for public transport, which integrates structural equation model (SEM and discrete choice model (DCM with categorized latent variables, was presented in this paper. Apart from identifying those important latent variables that affect mode choice for public transport, the objective of this study was also to develop an improved disaggregative model that better explains travel behavior of those decision-makers in choosing public transport. After extensive observations, selective latent variable sets which consist of latent variable components were chosen together with explicit variables in formulating the utility functions. Data collected in Chengdu city, China, were used to calibrate and validate the model. Results showed that the impact of fare on mode choice of public transport escalated in the SEM-DCM integrated model compared with the traditional logit model. The goodness of fit for the integrated model with latent variable sets is 0.201 higher than that of the traditional logit model, which proves that latent variables have an obvious impact on mode choice behavior, and the SEM-DCM integrated model has higher accuracy and stronger explanatory ability. The results are especially helpful for public transport operators to achieve higher mode share split by improving the service quality of public transport in terms of providing more convenience and better service environment for public transport users.

  4. The Impact of Employer Attitude to Green Commuting Plans on Reducing Car Driving: A Mixed Method Analysis

    Directory of Open Access Journals (Sweden)

    Chuan Ding

    2014-04-01

    Full Text Available Reducing car trips and promoting green commuting modes are generally considered important solutions to reduce the increase of energy consumption and transportation CO2 emissions. One potential solution for alleviating transportation CO2 emissions has been to identify a role for the employer through green commuter programs. This paper offers an approach to assess the effects of employer attitudes towards green commuting plans on commuter mode choice and the intermediary role car ownership plays in the mode choice decision process. A mixed method which extends the traditional discrete choice model by incorporating latent variables and mediating variables with a structure equation model was used to better understand the commuter mode choice behaviour. The empirical data were selected from Washington-Baltimore Regional Household Travel Survey in 2007-2008, including all the trips from home to workplace during the morning hours. The model parameters were estimated using the simultaneous estimation approach and the integrated model turns out to be superior to the traditional multinomial logit (MNL model accounting for the impact of employer attitudes towards green commuting. The direct and indirect effects of socio-demographic attributes and employer attitudes towards green commuting were estimated. Through the structural equation modelling with mediating variable, this approach confirmed the intermediary nature of car ownership in the choice process. The results found in this paper provide helpful information for transportation and planning policymakers to test the transportation and planning policies effects and encourage green commuting reducing transportation CO2 emissions.

  5. Latent lifestyle and mode choice decisions when travelling short distances

    DEFF Research Database (Denmark)

    Prato, Carlo Giacomo; Halldórsdóttir, Katrín; Nielsen, Otto Anker

    2016-01-01

    preferences and its tendency to accept these alternative travel options as realistic. However, this assumption appears quite unrealistic and the current study offers a different perspective: the mode choices when travelling short distances are likely related to lifestyle decisions. Short trip chains...... of a representative sample of the Danish population in the Copenhagen Region were analysed, and more specifically a latent class choice model was estimated to uncover latent lifestyle groups and choice specific travel behaviour. Results show that four lifestyle groups are identified in the population: car oriented...... on active travel modes), and trip purpose effect on mode selection. Consequently, when thinking about measures to increase the appeal of sustainable travel options, decision-makers should look at specific individuals within the population and more sensitive individuals to comfort and level...

  6. Essays on travel mode choice modeling: a discrete choice approach to the interactions between economic and behavioral theories

    OpenAIRE

    Bouscasse, Hélène

    2017-01-01

    The objective of this thesis is to incorporate aspects of psychology and behavioral economics theories in discrete choice models to promote a better understanding of mode choice at regional level. Part I presents the data collected in a choice experiment survey. Part II examines the inclusion of latent variables to explain mode choice. A literature review of integrated choice and latent variable models – that is, models combining a structural equation model and a discrete choice model – is fo...

  7. ESTIMATION OF TRIP MODE PROBABILITY CHOICE USING MULTINOMIAL LOGISTIC MODEL

    Directory of Open Access Journals (Sweden)

    Bilous, A.

    2012-06-01

    Full Text Available The step of modal split of the four step model for determination of urban travel demand is analyzed. Utility functions are composed, their coefficients are calibrated in TransCAD. Equations for estimation of trip mode choice probability are shown and the numerical illustration of estimation is given.

  8. Mode choice model for vulnerable motorcyclists in Malaysia.

    Science.gov (United States)

    Ibrahim Sheikh, A K; Radin Umar, R S; Habshah, M; Kassim, H; Stevenson, Mark; Ahmed, Hariza

    2006-06-01

    In developing countries, motorcycle use has grown in popularity in the past decades. Commensurate with this growth is the increase in death and casualties among motorcyclists in these countries. One of the strategic programs to minimize this problem is to reduce motorcyclists exposure by shifting them into safer modes of transport. This study aims to explore the differences in the characteristics of bus and motorcycle users. It identifies the factors contributing to their choice of transport mode and estimates the probability that motorcyclists might change their travel mode to a safer alternative; namely, bus travel. In this article, a survey of 535 motorcycle and bus users was conducted in seven districts of Selangor state, Malaysia. A binary logit model was developed for the two alternative modes, bus and motorcycle. It was found that travel time, travel cost, gender, age, and income level are significant in influencing motorcyclists' mode choice behavior. The probability of motorcycle riders shifting to public transport was also examined based on a scenario of a reduction in bus travel time and travel cost. Reduction of total travel time for the bus mode emerges as the most important element in a program aimed at attracting motorcyclists towards public transport and away from the motorcycle mode.

  9. PATIENTS EXPERIENCES OF INVOLVEMENT IN CHOICE OF DIALYSIS MODE.

    Science.gov (United States)

    Erlang, Anne S; Nielsen, Ida H; Hansen, Helle O B; Finderup, Jeanette

    2015-12-01

    International guidelines recommend that patients choose dialysis mode based on their own values and preferences; thus, involvement is needed in dialysis choice. A literature review indicated a lack of knowledge concerning patient involvement in decision-making, especially concerning patients' experiences of the decision-making process just after making the decision and before starting dialysis. To gather information about how patients experienced involvement in the decision-making process of renal substation therapy just after they have made the decision and before starting dialysis. A qualitative method with a phenomenological and hermeneutic approach. The study was based on individual semi-structured interviews with nine adult patients with chronic kidney disease. A data-driven analysis based on systematic text condensation was used. Patients are a significant part of the decision. Health care professionals contribute to the experience of being involved. Patients keep putting off the final choice. The patients found themselves involved in the choice of dialysis mode and have different views on what is needed to feel being involved. Information, interaction, and advice from health care professionals affect this experience. However, the experience of not having any symptoms caused patients to put off the final choice of dialysis mode. © 2015 European Dialysis and Transplant Nurses Association/European Renal Care Association.

  10. Particle number and mass exposure concentrations by commuter transport modes in Milan, Italy

    Directory of Open Access Journals (Sweden)

    Senem Ozgen

    2016-03-01

    Full Text Available There is increasing awareness amongst the general public about exposure to atmospheric pollution while travelling in urban areas especially when taking active travelling modes such as walking and cycling. This study presents a comparative investigation of ultrafine particles (UFP, PM10, PM2.5, PM1 exposure levels associated with four transport modes (i.e., walking, cycling, car, and subway in the city of Milan measured by means of portable instruments. Significant differences in particle exposure between transport modes were found. The subway mode was characterized by the highest PM mass concentrations: PM10, PM2.5, PM1 subway levels were respectively about 2-4-3 times higher than those of the car and open air active modes (i.e. cycling and walking. Conversely, these latter modes displayed the highest UFP levels about 2 to 3 times higher than the subway and car modes, highlighting the influence of direct traffic emissions. The car mode (closed windows, air conditioning and air recirculation on reported the lowest PM and UFP concentration levels. In particular, the open-air/car average concentration ratio varied from about 2 for UFP up to 4 for PM1 and 6 for PM10 and PM2.5, showing differences that increase with increasing particle size. This work points out that active mode travelling in Milan city centre in summertime results in higher exposure levels than the car mode. Walkers’ and cyclists’ exposure levels is expected to be even higher during wintertime, due to the higher ambient PM and UFP concentration. Interventions intended to re-design the urban mobility should therefore include dedicated routes in order to limit their exposure to PM and UFP by increasing their distance from road traffic.

  11. Evaluation of Neighbourhood Characteristics and Active Transport Mode Choice

    OpenAIRE

    Tayebeh Saghapour; Sara Moridpour; Russell George Thompson

    2017-01-01

    One of the common aims of transport policy makers is to switch people’s travel to active transport. For this purpose, a variety of transport goals and investments should be programmed to increase the propensity towards active transport mode choice. This paper aims to investigate whether built environment features in neighbourhoods could enhance the odds of active transportation. The present study introduces an index measuring public transport accessibility (PTAI), and a walkability index alon...

  12. On fully superconducting rectifiers and fluxpumps. A review. Part 2: Commutation modes, characteristics and switches

    NARCIS (Netherlands)

    van de Klundert, L.J.M.; ten Kate, Herman H.J.

    1981-01-01

    This paper forms the second part of the review. Full and half wave superconducting transformer rectifiers are analysed. Modes of operation and loss mechanisms are detailed and a comparison between the behaviour of dynamos and rectifiers is presented. Investigations carried out to date still leave

  13. Reaching Hard-to-Survey Populations: Mode Choice and Mode Preference

    NARCIS (Netherlands)

    Haan, Marieke; Ongena, Yfke P.; Aarts, Kees

    2014-01-01

    This study assesses the effect of response-mode choices on response rates, and responsemode preferences of hard-to-survey populations: young adults, full-time workers, big city inhabitants, and non-Western immigrants. Using address-based sampling, a stratified sample of 3,496 households was

  14. Multinomial Logit Model of Choices of Internet Modes in Iraq

    OpenAIRE

    Ph.D. Almas Heshmati; Ph.D. Firas H. Al-Hammadany

    2014-01-01

    Iraq is a country that has the potential to explode onto the Internet market due to the fact that much of Iraq is still largely without access to the Internet. Iraq¡¯s market has much room for corporate and individual investments in Internet technology, mainly, Internet access. However, this requires a deep understanding of the user with regards to the Internet and the market characteristics involved. This study is concerned with the users¡¯ choice of Internet mode connections in Iraq. There ...

  15. Choice of a Perioperative Analgesia Mode during Hip Joint Replacement

    Directory of Open Access Journals (Sweden)

    D. B. Borisov

    2010-01-01

    Full Text Available Objective: to evaluate the efficiency and safety of various perioperative analgesia modes during total hip joint replacement (THR. Subjects and methods. A randomized controlled trial enrolled 90 patients who were divided into 3 groups according to the choice of a perioperative analgesia mode on day 1: general sevofluorane anesthesia, by switching to intravenous patient-controlled analgesia with fentanyl (PCA, GA group, a combination of general and spinal bupiva-caine anesthesia, by switching to PCA with fentanyl (SA group, a combination of general and epidural ropivacaine anesthesia with continuous postoperative epidural ropivacaine infusion (EA group. All the patients received non-opi-oid analgesics after surgery. Results. Prolonged epidural block ensures better postoperative analgesia at rest and during mobilization and a less need for opioids than other analgesia modes (p<0.05. With neuroaxial block, the preoperative need for sympatomimetics is much higher than that in the GA group (p<0.05. There is also a trend toward a higher incidence of cardiac arrhythmias and postoperative nausea and vomiting in the SA and EA groups. There are no differences in the frequency of hemotransfusion and postoperative complications and the length of hospital stay. Conclusion. Prolonged epidural block provides excellent perioperative analgesia during THR, but the risk-benefit ratio needs to be carefully assessed when an analgesia mode is chosen.

  16. Active commuting to school: How far is too far?

    LENUS (Irish Health Repository)

    Nelson, Norah M

    2008-01-01

    ABSTRACT: BACKGROUND: Walking and cycling to school provide a convenient opportunity to incorporate physical activity into an adolescent\\'s daily routine. School proximity to residential homes has been identified as an important determinant of active commuting among children. The purpose of this study is to identify if distance is a barrier to active commuting among adolescents, and if there is a criterion distance above which adolescents choose not to walk or cycle. METHODS: Data was collected in 2003-05 from a cross-sectional cohort of 15-17 yr old adolescents in 61 post primary schools in Ireland. Participants self-reported distance, mode of transport to school and barriers to active commuting. Trained researchers took physical measurements of height and weight. The relation between mode of transport, gender and population density was examined. Distance was entered into a bivariate logistic regression model to predict mode choice, controlling for gender, population density socio-economic status and school clusters. RESULTS: Of the 4013 adolescents who participated (48.1% female, mean age 16.02 +\\/- 0.661), one third walked or cycled to school. A higher proportion of males than females commuted actively (41.0 vs. 33.8%, chi2 (1) = 22.21, p < 0.001, r = -0.074). Adolescents living in more densely populated areas had greater odds of active commuting than those in the most sparsely populated areas (chi2 (df = 3) = 839.64, p < 0.001). In each density category, active commuters travelled shorter distances to school. After controlling for gender and population density, a 1-mile increase in distance decreased the odds of active commuting by 71% (chi2 (df = 1) = 2591.86, p < 0.001). The majority of walkers lived within 1.5 miles and cyclists within 2.5 miles. Over 90% of adolescents who perceived distance as a barrier to active commuting lived further than 2.5 miles from school. CONCLUSION: Distance is an important perceived barrier to active commuting and a predictor

  17. Commutative Algebra

    CERN Document Server

    Fontana, Marco; Olberding, Bruce; Swanson, Irena

    2011-01-01

    Commutative algebra is a rapidly growing subject that is developing in many different directions. This volume presents several of the most recent results from various areas related to both Noetherian and non-Noetherian commutative algebra. This volume contains a collection of invited survey articles by some of the leading experts in the field. The authors of these chapters have been carefully selected for their important contributions to an area of commutative-algebraic research. Some topics presented in the volume include: generalizations of cyclic modules, zero divisor graphs, class semigrou

  18. MIT employee commuter behavior trial.

    Science.gov (United States)

    2013-04-01

    The objectives of the project included the following: : To evaluate the potential impact (in terms of commuter mode shifts) from the introduction of : disruptive technologies at the Massachusetts Institute of Technology in Cambridge, MA, includin...

  19. USING DECISION TREES FOR ESTIMATING MODE CHOICE OF TRIPS IN BUCA-IZMIR

    Directory of Open Access Journals (Sweden)

    L. O. Oral

    2013-05-01

    Full Text Available Decision makers develop transportation plans and models for providing sustainable transport systems in urban areas. Mode Choice is one of the stages in transportation modelling. Data mining techniques can discover factors affecting the mode choice. These techniques can be applied with knowledge process approach. In this study a data mining process model is applied to determine the factors affecting the mode choice with decision trees techniques by considering individual trip behaviours from household survey data collected within Izmir Transportation Master Plan. From this perspective transport mode choice problem is solved on a case in district of Buca-Izmir, Turkey with CRISP-DM knowledge process model.

  20. Improving participation rates by providing choice of participation mode: two randomized controlled trials.

    Science.gov (United States)

    Heijmans, Naomi; van Lieshout, Jan; Wensing, Michel

    2015-04-02

    Low participation rates reduce effective sample size, statistical power and can increase risk for selection bias. Previous research suggests that offering choice of participation mode can improve participation rates. However, few head-to-head trials compared choice of participation mode using telephone interviews and postal questionnaires as modes of interest. Aiming to explore effects of choice of participation, two randomized controlled trials were performed comparing participation rates of patients provided with and without choice of participation mode, using interviews and questionnaires as participation modes. Two trials were embedded in a larger study on cardiovascular risk management in primary care. Patients with a chronic cardiovascular condition recruited for the larger study were invited to participate in an additional survey on social networks, using invitations with and without choice of participation mode. Primary outcome was participation rate. Other outcomes of interest were participation rate conditional on willingness to participate, and initial willingness to participate. In trial 1 we compared outcomes after choice of participation mode (interview or questionnaire) with invitations for participation in a telephone interview. In Trial 2 results for choice of participation mode were compared with postal questionnaires. In Trial 1 no differences were found in participation rates (65% vs 66%, p = 0.853) although conditional participation rate was highest for interviews (90% vs 72%, p choice of participation mode was provided (90% versus 73%, p choice of participation mode was provided (59% vs 46%, p choice of participation mode had benefit on participation rates compared to invitations to participate in questionnaires, but not when compared to invitations to participate in telephone interviews. Current Controlled Trials ISRCTN89237105 .

  1. Improving participation rates by providing choice of participation mode: two randomized controlled trials

    NARCIS (Netherlands)

    Heijmans, N.; Lieshout, J. van; Wensing, M.J.

    2015-01-01

    BACKGROUND: Low participation rates reduce effective sample size, statistical power and can increase risk for selection bias. Previous research suggests that offering choice of participation mode can improve participation rates. However, few head-to-head trials compared choice of participation mode

  2. A comparative study of machine learning classifiers for modeling travel mode choice

    NARCIS (Netherlands)

    Hagenauer, J; Helbich, M

    2017-01-01

    The analysis of travel mode choice is an important task in transportation planning and policy making in order to understand and predict travel demands. While advances in machine learning have led to numerous powerful classifiers, their usefulness for modeling travel mode choice remains largely

  3. Active commuting to school: How far is too far?

    Directory of Open Access Journals (Sweden)

    Moyna Niall M

    2008-01-01

    Full Text Available Abstract Background Walking and cycling to school provide a convenient opportunity to incorporate physical activity into an adolescent's daily routine. School proximity to residential homes has been identified as an important determinant of active commuting among children. The purpose of this study is to identify if distance is a barrier to active commuting among adolescents, and if there is a criterion distance above which adolescents choose not to walk or cycle. Methods Data was collected in 2003–05 from a cross-sectional cohort of 15–17 yr old adolescents in 61 post primary schools in Ireland. Participants self-reported distance, mode of transport to school and barriers to active commuting. Trained researchers took physical measurements of height and weight. The relation between mode of transport, gender and population density was examined. Distance was entered into a bivariate logistic regression model to predict mode choice, controlling for gender, population density socio-economic status and school clusters. Results Of the 4013 adolescents who participated (48.1% female, mean age 16.02 ± 0.661, one third walked or cycled to school. A higher proportion of males than females commuted actively (41.0 vs. 33.8%, χ2 (1 = 22.21, p 2 (df = 3 = 839.64, p 2 (df = 1 = 2591.86, p Conclusion Distance is an important perceived barrier to active commuting and a predictor of mode choice among adolescents. Distances within 2.5 miles are achievable for adolescent walkers and cyclists. Alternative strategies for increasing physical activity are required for individuals living outside of this criterion.

  4. Understanding adolescents' intentions to commute by car or bicycle as adults

    DEFF Research Database (Denmark)

    Sigurdardottir, Sigrun Birna; Kaplan, Sigal; Møller, Mette

    2013-01-01

    This study focuses on the intentions of adolescents to commute by car or bicycle as adults. The behavioral model is based on intrapersonal and interpersonal constructs from the theory of planned behavior extended to include constructs from the institutional, community and policy domains. Data from...... location, current mode choice to daily activities, and parental travel patterns....

  5. A dynamic parking charge optimal control model under perspective of commuters' evolutionary game behavior

    Science.gov (United States)

    Lin, XuXun; Yuan, PengCheng

    2018-01-01

    In this research we consider commuters' dynamic learning effect by modeling the trip mode choice behavior from a new perspective of dynamic evolutionary game theory. We explore the behavior pattern of different types of commuters and study the evolution path and equilibrium properties under different traffic conditions. We further establish a dynamic parking charge optimal control (referred to as DPCOC) model to alter commuters' trip mode choice while minimizing the total social cost. Numerical tests show. (1) Under fixed parking fee policy, the evolutionary results are completely decided by the travel time and the only method for public transit induction is to increase the parking charge price. (2) Compared with fixed parking fee policy, DPCOC policy proposed in this research has several advantages. Firstly, it can effectively turn the evolutionary path and evolutionary stable strategy to a better situation while minimizing the total social cost. Secondly, it can reduce the sensitivity of trip mode choice behavior to traffic congestion and improve the ability to resist interferences and emergencies. Thirdly, it is able to control the private car proportion to a stable state and make the trip behavior more predictable for the transportation management department. The research results can provide theoretical basis and decision-making references for commuters' mode choice prediction, dynamic setting of urban parking charge prices and public transit induction.

  6. Mode Choice of Undergraduates : A Case Study of Lecture Trips in Nigeria.

    OpenAIRE

    Moses Olaniran Olawole; Olabisi Michael Olapoju

    2017-01-01

    Abstract Travel behavior and determinants of mode choice of university students in Nigeria are neither well understood nor well represented in literature. This study model is modal choice of undergraduates, using data from students travel survey and logistic regression to determine factors influence modal choice of undergraduate students in Obafemi Awolowo University Ile-Ife, Nigeria. The results indicate that walking dominate modes for on-campus and commercial bus for off-campus students, wh...

  7. The effect of commuting microenvironment on commuter exposures to vehicular emission in Hong Kong

    Science.gov (United States)

    Chan, L. Y.; Chan, C. Y.; Qin, Y.

    Vehicular exhaust emission has gradually become the major air pollution source in modern cities and traffic related exposure is found to contribute significantly to total human exposure level. A comprehensive survey was conducted from November 1995 to July 1996 in Hong Kong to assess the effect of traffic-induced air pollution inside different commuting microenvironments on commuter exposure. Microenvironmental monitoring is performed for six major public commuting modes (bus, light bus, MTR, railway, tram, ferry), plus private car and roadside pavement. Traffic-related pollutants, CO, NO x, THC and O 3 were selected as the target pollutants. The results indicate that commuter exposure is highly influenced by the choice of commuting microenvironment. In general, the exposure level in decreasing order of measured pollutant level for respective commuting microenvironments are: private car, the group consisting light bus, bus, tram and pavement, MTR and train, and finally ferry. In private car, the CO level is several times higher than that in the other microenvironments with a trip averaged of 10.1 ppm and a maximum of 24.9 ppm. Factors such as the body position of the vehicle, intake point of the ventilation system, fuel used, ventilation, transport mode, road and driving conditions were used in the analysis. Inter-microenvironment, intra-microenvironment and temporal variation of CO concentrations were used as the major indicator. The low body position and low intake point of the ventilation system of the private car are believed to be the cause of higher intake of exhaust of other vehicles and thus result in high pollution level in this microenvironment. Compared with other metropolis around the world and the Hong Kong Air Quality Objectives (HKAQO), exposure levels of commuter to traffic-related air pollution in Hong Kong are relatively low for most pollutants measured. Only several cases of exceedence of HKAQO by NO 2 were recorded. The strong prevailing wind

  8. Neighborhood crime and transit station access mode choice - phase III of neighborhood crime and travel behavior.

    Science.gov (United States)

    2015-08-01

    This report provides the findings from the third phase of a three-part study about the influences of neighborhood crimes on travel : mode choice. While previous phases found evidence that high levels of neighborhood crime discourage people from choos...

  9. TCRP H-37 Characteristics of Premium Transit Services That Affect Mode Choice: Summary of Phase 1

    Science.gov (United States)

    2010-11-15

    This research seeks to improve the understanding of the full range of determinants for mode choice behavior and to offer practical solutions to practitioners on representing and distinguishing these characteristics in travel demand forecasting models...

  10. Travel mode choice and travel satisfaction : bridging the gap between decision utility and experienced utility

    OpenAIRE

    De Vos, Jonas; Mokhtarian, Patricia L; Schwanen, Tim; Van Acker, Veronique; Witlox, Frank

    2016-01-01

    Over the past decades research on travel mode choice has evolved from work that is informed by utility theory, examining the effects of objective determinants, to studies incorporating more subjective variables such as habits and attitudes. Recently, the way people perceive their travel has been analyzed with transportation-oriented scales of subjective wellbeing, and particularly the satisfaction with travel scale. However, studies analyzing the link between travel mode choice (i.e., decisio...

  11. Modelling Choice: Factors Influencing Modes of Delivery in Australian Universities

    Science.gov (United States)

    Smith, Andrew; Ling, Peter; Hill, Doug

    2008-01-01

    This paper reports the findings of a study of Multiple Modes of Delivery in Australian universities that was commissioned by Australian Universities Teaching Committee over the period 2001-2004. The project examined and described the various means of educational delivery deployed by Australian universities. It identified the pedagogical,…

  12. Do labeled versus unlabeled treatments of alternatives’ names influence stated choice outputs? Results from a mode choice study

    Science.gov (United States)

    Jin, Wen; Jiang, Hai; Liu, Yimin; Klampfl, Erica

    2017-01-01

    Discrete choice experiments have been widely applied to elicit behavioral preferences in the literature. In many of these experiments, the alternatives are named alternatives, meaning that they are naturally associated with specific names. For example, in a mode choice study, the alternatives can be associated with names such as car, taxi, bus, and subway. A fundamental issue that arises in stated choice experiments is whether to treat the alternatives’ names as labels (that is, labeled treatment), or as attributes (that is, unlabeled treatment) in the design as well as the presentation phases of the choice sets. In this research, we investigate the impact of labeled versus unlabeled treatments of alternatives’ names on the outcome of stated choice experiments, a question that has not been thoroughly investigated in the literature. Using results from a mode choice study, we find that the labeled or the unlabeled treatment of alternatives’ names in either the design or the presentation phase of the choice experiment does not statistically affect the estimates of the coefficient parameters. We then proceed to measure the influence toward the willingness-to-pay (WTP) estimates. By using a random-effects model to relate the conditional WTP estimates to the socioeconomic characteristics of the individuals and the labeled versus unlabeled treatments of alternatives’ names, we find that: a) Given the treatment of alternatives’ names in the presentation phase, the treatment of alternatives’ names in the design phase does not statistically affect the estimates of the WTP measures; and b) Given the treatment of alternatives’ names in the design phase, the labeled treatment of alternatives’ names in the presentation phase causes the corresponding WTP estimates to be slightly higher. PMID:28806764

  13. Do labeled versus unlabeled treatments of alternatives' names influence stated choice outputs? Results from a mode choice study.

    Science.gov (United States)

    Jin, Wen; Jiang, Hai; Liu, Yimin; Klampfl, Erica

    2017-01-01

    Discrete choice experiments have been widely applied to elicit behavioral preferences in the literature. In many of these experiments, the alternatives are named alternatives, meaning that they are naturally associated with specific names. For example, in a mode choice study, the alternatives can be associated with names such as car, taxi, bus, and subway. A fundamental issue that arises in stated choice experiments is whether to treat the alternatives' names as labels (that is, labeled treatment), or as attributes (that is, unlabeled treatment) in the design as well as the presentation phases of the choice sets. In this research, we investigate the impact of labeled versus unlabeled treatments of alternatives' names on the outcome of stated choice experiments, a question that has not been thoroughly investigated in the literature. Using results from a mode choice study, we find that the labeled or the unlabeled treatment of alternatives' names in either the design or the presentation phase of the choice experiment does not statistically affect the estimates of the coefficient parameters. We then proceed to measure the influence toward the willingness-to-pay (WTP) estimates. By using a random-effects model to relate the conditional WTP estimates to the socioeconomic characteristics of the individuals and the labeled versus unlabeled treatments of alternatives' names, we find that: a) Given the treatment of alternatives' names in the presentation phase, the treatment of alternatives' names in the design phase does not statistically affect the estimates of the WTP measures; and b) Given the treatment of alternatives' names in the design phase, the labeled treatment of alternatives' names in the presentation phase causes the corresponding WTP estimates to be slightly higher.

  14. Choice of Artificial Ventilation Mode in Premature Neonates with Respiratory Distress Syndrome

    OpenAIRE

    S. A. Perepelitsa; Golubev, A M; V. V. Moroz

    2010-01-01

    Objective: to choose an artificial ventilation (AV) mode in premature neonates with respiratory distress syndrome (RDS) after administration of exogenous surfactants and to compare the duration of AV and the development of complications in relation to the type of an exogenous surfactant. Subjects and methods. The paper presents the results of choosing an AV mode in 122 premature neonates with severe RDS. The choice of an AV mode, the duration of respiratory therapy, and the development of com...

  15. Relationship between train users’ perceptions of walkability with access and egress mode choice

    Directory of Open Access Journals (Sweden)

    Syafriharti Romeiza

    2018-01-01

    Full Text Available The purpose of this study is to understand whether there is a relationship between train users’ perceptions of walkability in built environment of trip origin with access mode choice and between train users’ perceptions of walkability in built environment of trip destination with egress mode choice. Train users are who ride from Cicalengka station Bandung Regency, West Java, Indonesia. To analyze the relationship is used crosstab method. The perceptual factors about walkability are those perceived by the train users consisting of walking distance, safety, comfort, and secure from crime, both in origin and destination of the built environment. The mode choice consist of walking, paratransit, motorcycle taxi, and own vehicles (or others for egress mode. To better understand the relationship is used several control variables, that are trip purposes, train usage, gender, and age. For access trip there is another control variable, that is vehicle ownership. Train users' perceptions of walkability have a relationship with both the access and the egress mode choice, except for the security aspect. The influence of control variables on the relationship between perceptions of walkability with access/egress mode choice varies for walking distance, safety, and comfort.

  16. Nurse/physician conflict management mode choices: implications for improved collaborative practice.

    Science.gov (United States)

    Hendel, Tova; Fish, Miri; Berger, Ornit

    2007-01-01

    In today's complex healthcare organizations, conflicts between physicians and nurses occur daily. Consequently, organizational conflict has grown into a major subfield of organizational behavior. Researchers have claimed that conflict has a beneficial effect on work group function and identified collaboration as one of the intervening variables that may explain the relationship between magnet hospitals and positive patient outcomes. The purpose of this study was to identify and compare conflict mode choices of physicians and head nurses in acute care hospitals and examine the relationship of conflict mode choices with their background characteristics. In a cross-sectional correlational study, 75 physicians and 54 head nurses in 5 hospitals were surveyed, using the Thomas-Kilmann Conflict Mode Instrument. No difference was found between physicians and nurses in choice of the most frequently used mode in conflict management. The compromising mode was found to be the significantly most commonly chosen mode (P = .00) by both. Collaborating was chosen significantly more frequently among head nurses (P = .001) and least frequently among physicians (P = .00). Most of the respondents' characteristics were not found to be correlated with mode choices. The findings indicate a need to enhance partnerships in the clinical environment to ensure quality patient care and staff satisfaction.

  17. Development of discrete choice model considering internal reference points and their effects in travel mode choice context

    Science.gov (United States)

    Sarif; Kurauchi, Shinya; Yoshii, Toshio

    2017-06-01

    In the conventional travel behavior models such as logit and probit, decision makers are assumed to conduct the absolute evaluations on the attributes of the choice alternatives. On the other hand, many researchers in cognitive psychology and marketing science have been suggesting that the perceptions of attributes are characterized by the benchmark called “reference points” and the relative evaluations based on them are often employed in various choice situations. Therefore, this study developed a travel behavior model based on the mental accounting theory in which the internal reference points are explicitly considered. A questionnaire survey about the shopping trip to the CBD in Matsuyama city was conducted, and then the roles of reference points in travel mode choice contexts were investigated. The result showed that the goodness-of-fit of the developed model was higher than that of the conventional model, indicating that the internal reference points might play the major roles in the choice of travel mode. Also shown was that the respondents seem to utilize various reference points: some tend to adopt the lowest fuel price they have experienced, others employ fare price they feel in perceptions of the travel cost.

  18. Policy sensitive mode choice analysis of Port-Said City, Egypt

    Directory of Open Access Journals (Sweden)

    Marwa El-Sayed El-Bany

    2014-12-01

    Full Text Available This paper aimed at developing advanced Logit discrete choice models with several individual and mode attributes affecting the prediction of individual choice. The models have been applied to Port-Said (PS city and have been used to investigate innovative transport systems such as Bus Rapid Transit (BRT as a hypothetical mode situation beside the regular modes of transport (car and taxi. The methodology provides data collection of PS transportation mode system and develops Multinomial Logit Model (MNL, Nested Logit Model (NL, and Mixed Logit Model (MXL using Visual-tm Software. The survey was formed by the Stated Preference (SP technique conducted for individuals from all PS zones and the predictable travel mode choice behavior was analyzed. The findings showed that in PS, income is the most important attribute affecting the mode choice behavior model. The high values and positive signs of income parameters indicate that the higher income earners are more likely to use private car than taxi or bus. Contrary to most cases in developed countries, out-of-vehicle time that represents the accessibility shows higher impacts than the in-vehicle time as a result of poor access facilities in developing countries.

  19. Domestic airport passenger access mode choice decisions in a multi-airport region of South Africa

    Directory of Open Access Journals (Sweden)

    Stephen Carstens

    2014-03-01

    Full Text Available The ground access mode used by air passengers to an airport has a vital impact on infrastructural and environmental decisions. An important aspect of a passenger’s mode choice is the sensitivity to factors such as access time and access cost. The objective of this research was to analyse air passenger’s sensitivity to access mode choice attributes, that is,access time, access cost, parking time and parking cost at two airports in Johannesburg, South Africa. A stated choice experiment was used to obtain the information and a latent class model was estimated. In general, discrete choice experiments are designed to reveal respondent(preference heterogeneity and the latent class model allows for this heterogeneity to be modelled discretely. The estimated results indicated that three latent classes provided the best fit with preference heterogeneity evident from the set of parameter estimates. The access mode used was found to be the only significant covariate in the class assignment model. The respondents’ willingness to pay for a reduction in access time was estimated and it indicated that respondents had the highest access time willingness-to-pay value for the taxi as access mode. In addition, it was estimated that passengers being dropped off at the airport had a higher access time willingness-to-pay than passengers that used their own vehicles to the airport. The research results confirmed the presence of respondent heterogeneity (according to access mode which resulted in different access time willingness-to-pay values.

  20. A hybrid mode choice model to account for the dynamic effect of inertia over time

    DEFF Research Database (Denmark)

    Cherchi, Elisabetta; Börjesson, Maria; Bierlaire, Michel

    gathered over a continuous period of time, six weeks, to study both inertia and the influence of habits. Tendency to stick with the same alternative is measured through lagged variables that link the current choice with the previous trip made with the same purpose, mode and time of day. However, the lagged......The influence of habits, giving rise to inertia effect, in the choice process has been intensely debated in the literature. Typically inertia is accounted for by letting the indirect utility functions of the alternatives of the choice situation at time t depend on the outcome of the choice made...... confirms that the tendency to stick with the same alternative varies not only among modes but also across individuals as a function of the individual propensity to undertake habitual behavior....

  1. An experimental study on cumulative prospect theory learning model of travelers’ dynamic mode choice under uncertainty

    Directory of Open Access Journals (Sweden)

    Chao Yang

    2017-06-01

    Full Text Available In this paper, we examined travelers’ dynamic mode choice behavior under travel time variability. We found travelers’ inconsistent risk attitudes through a binary mode choice experiment. Although the results deviated from the traditional utility maximization theory and could not be explained by the payoff variability effect, they could be well captured in a cumulative prospect theory (CPT framework. After considering the imperfect memory effect, we found that the prediction ability of the cumulative prospect theory learning (CPTL model could be significantly improved. The experimental results were also compared with the CPTL model and the reinforcement learning (REL model. This study empirically showed the potential of alternative theories to better capture travelers’ day-to-day mode choice behavior under uncertainty. A new definition of willingness to pay (WTP in a CPT framework was provided to explicitly consider travelers’ perceived value increases in travel time.

  2. Choice of Human-Computer Interaction Mode in Stroke Rehabilitation.

    Science.gov (United States)

    Mousavi Hondori, Hossein; Khademi, Maryam; Dodakian, Lucy; McKenzie, Alison; Lopes, Cristina V; Cramer, Steven C

    2016-03-01

    Advances in technology are providing new forms of human-computer interaction. The current study examined one form of human-computer interaction, augmented reality (AR), whereby subjects train in the real-world workspace with virtual objects projected by the computer. Motor performances were compared with those obtained while subjects used a traditional human-computer interaction, that is, a personal computer (PC) with a mouse. Patients used goal-directed arm movements to play AR and PC versions of the Fruit Ninja video game. The 2 versions required the same arm movements to control the game but had different cognitive demands. With AR, the game was projected onto the desktop, where subjects viewed the game plus their arm movements simultaneously, in the same visual coordinate space. In the PC version, subjects used the same arm movements but viewed the game by looking up at a computer monitor. Among 18 patients with chronic hemiparesis after stroke, the AR game was associated with 21% higher game scores (P = .0001), 19% faster reaching times (P = .0001), and 15% less movement variability (P = .0068), as compared to the PC game. Correlations between game score and arm motor status were stronger with the AR version. Motor performances during the AR game were superior to those during the PC game. This result is due in part to the greater cognitive demands imposed by the PC game, a feature problematic for some patients but clinically useful for others. Mode of human-computer interface influences rehabilitation therapy demands and can be individualized for patients. © The Author(s) 2015.

  3. Integrating Regret Psychology to Travel Mode Choice for a Transit-Oriented Evacuation Strategy

    Directory of Open Access Journals (Sweden)

    Shi An

    2015-06-01

    Full Text Available Facing the potential dangers from sudden disasters in urban cities, emergency administrators have to make an appropriate evacuation plan to mitigate negative consequences. However, little attention has been paid to evacuee real decision psychology when developing a strategy. The aim of this paper is to analyze evacuee mode choice behavior considering regret aversion psychology during evacuation. First, the utility-based and regret-based models are formulated to obtain evacuees’ preferences on travel mode choice, respectively. According to the data collected from the stated preference (SP survey on evacuee mode choice, the estimation results show that the regret-based model performs better than the utility model. Moreover, based on the estimates from behavioral analysis, the elasticities of evacuee mode choices are calculated, and transit strategy simulation is undertaken to investigate the influence on evacuee mode switching from private automobile to public transit. The results are expected to help emergency administrators to make a transit-oriented strategy for a sustainable evacuation plan, especially for the benefit of carless people.

  4. Dynamic Interactions between Commuters’ Mode Choice Behaviour and Integrated Traveller Information

    Directory of Open Access Journals (Sweden)

    Meng Meng

    2015-12-01

    Full Text Available A commuter’s mode choice decision in response to provided traveller information is directly dependent on the temporal and spatial interactions between the available travel modes, the network performance and control schemes, and the supplied traveller information. A self-developed simulation model – Intelligent Network Simulation Model (INSIM – was employed to simulate travel scenarios in a multimodal transportation network. A set of experiments was designed to analyse and evaluate the influence of traffic information on commuter’s mode choice, using a medium-sized area in Singapore. Simulation results showed that the private-to-public mode switch propensity bears a strong and direct relation with amount of disseminated integrated multimodal traveller information (IMTI as well as timeliness of information update. Other influential factors include degrees of accessibility and compliance to IMTI, and congestion-related events such as accidents.

  5. Choice Model and Influencing Factor Analysis of Travel Mode for Migrant Workers: Case Study in Xi'an, China

    National Research Council Canada - National Science Library

    Hong Chen; Zuo-xian Gan; Yu-ting He

    2015-01-01

      Based on the basic theory and methods of disaggregate choice model, the influencing factors in travel mode choice for migrant workers are analyzed, according to 1366 data samples of Xi'an migrant workers...

  6. Using New Mode Choice Model Nesting Structures to Address Emerging Policy Questions: A Case Study of the Pittsburgh Central Business District

    Directory of Open Access Journals (Sweden)

    Zulqarnain H. Khattak

    2017-11-01

    Full Text Available As transportation activities affect a region’s environmental quality, knowing why individuals prefer certain modes can help a region make judicious transportation investments. Using a nested logit model, this paper studies the behavior of commuters to downtown Pittsburgh who use auto, bus, light rail, walking, and biking. Although statistical measures influence the selection of a nesting structure, another criterion for model selection is the policy questions such models inform. Hence this paper demonstrates how an alternative model structure allows planners to consider new policy questions. For example, how might a change in parking fee affect greenhouse gas emission (GHGs? The proposed model showed that a 5%, 10% and 15% increase in parking cost reduces GHGs by 7.3%, 9% and 13.2%, respectively, through increasing carpoolers’ mode share. Because the proposed model forecasts mode choices of certain groups of travelers with higher accuracy (compared to an older model that did not consider the model selection criteria presented here, the proposed model strengthens policymakers’ ability to consider environmental impacts of interest to the region (in this case, GHGs. The paper does not suggest that one nesting structure is always preferable; rather the nesting structure must be chosen with the policy considerations in mind.

  7. Travel mode choice and travel satisfaction: bridging the gap between decision utility and experienced utility

    NARCIS (Netherlands)

    De Vos, J.; Mokhtarian, P.L.; Schwanen, T.; Van Acker, V.; Witlox, F.

    2016-01-01

    Over the past decades research on travel mode choice has evolved from work that is informed by utility theory, examining the effects of objective determinants, to studies incorporating more subjective variables such as habits and attitudes. Recently, the way people perceive their travel has been

  8. The determinants of mode choice for family visits - evidence from Dutch panel data

    NARCIS (Netherlands)

    Rubin, O.; Mulder, C.H.; Bertolini, L.

    2014-01-01

    We use panel data to estimate multinomial logistic regressions for the effect of household composition, car ownership, distance between family members, and degree of urbanization on mode choice for family visits in the Netherlands. Based on Mundlak’s formulation our model accounts for unobserved

  9. Understanding mode choice in the Chinese context: the case of Nanjing Metropolitan Area

    NARCIS (Netherlands)

    Feng, Jianxi|info:eu-repo/dai/nl/342291327; Dijst, Martin|info:eu-repo/dai/nl/070793085; Wissink, Bart; Prillwitz, Jan|info:eu-repo/dai/nl/328231797

    In post-reform China, rapid motorisation causes various problems like traffic congestion, diminishing road safety and air pollution. Adequate policies necessitate an understanding of the forces behind changing mode choices, but the rapidly developing literature is not complete yet. This paper aims

  10. PASSENGER CAR USAGE FOR COMMUTING TO WORK AS A FUNCTION OF LIMITED STAY AT CAR PARKS

    Directory of Open Access Journals (Sweden)

    Valentina Basarić

    2013-07-01

    Full Text Available The analysis of the experiences in European cities, following the implementation of different transport policy measures, has led to a conclusion that parking policy measures have the dominant effect on the choice of private car as a mode of transport. This effect is the greatest for the commutes to work, characterized by the longest duration of parking space occupancy. Given the aforementioned experiences in developed European cities, the main aim of the study presented here was the determination of a relationship between limiting the duration of parking space occupancy in the Novi Sad city centre and the transport participants’ decision whether or not to use passenger car to commute to work. Based on the established interdependence between these parameters, we developed a mathematical model for calculating a number of expected car (commuting journeys that terminate in the city centre as a function of limited duration of parking space occupancy.  

  11. Choice of mode of delivery in a subsequent pregnancy after OASI: a survey among Dutch gynecologists.

    Science.gov (United States)

    Donners, Judith J A E; Kluivers, Kirsten B; de Leeuw, Jan W; van Dillen, Jeroen; van Kuijk, Sander M J; Weemhoff, Mirjam

    2017-10-01

    National and international guidelines do not provide clear recommendations on the mode of delivery in a subsequent pregnancy after obstetric anal sphincter injury (OASI). The aim of this study was to investigate the opinion of gynecologists in The Netherlands on this choice and the extent to which this choice is affected by the gynecologist's characteristics. Of 973 gynecologists sent a questionnaire seeking their opinion on the mode of delivery in 16 different case descriptions, 234 (24%) responded. Factors influencing the opinion of the respondents on the mode of delivery, the presence of anal symptoms, the degree of OASI and the characteristics of the respondents were analyzed by univariate and multivariate logistic regression analysis. Recommendations on the mode of delivery in a subsequent pregnancy after OASI showed considerable variation. The recommendations depended on (previous) symptoms and the degree of OASI. For gynecologists who based their recommendations on endoanal ultrasonography outcomes (7-20% depending on the case), the degree of OASI and severity of (previous) symptoms were less important. Gynecologists basing their recommendations on endoanal ultrasonography recommended a primary cesarean section less often. Gynecologist's characteristics (including years of experience, type of hospital and subspecialty) had a small effect on their recommendations on the mode of delivery. Due to lack of evidence, recommendations of gynecologists in The Netherlands on the mode of delivery in a subsequent pregnancy after OASI vary widely and depend on (previous) symptoms and the degree of OASI. Gynecologists who based their recommendations on endoanal ultrasonography outcomes recommended cesarean section less often.

  12. Variability in baseline travel behaviour as a predictor of changes in commuting by active travel, car and public transport : A natural experimental study

    NARCIS (Netherlands)

    Heinen, E.; Ogilvie, David

    2016-01-01

    Purpose: To strengthen our understanding of the impact of baseline variability in mode choice on the likelihood of travel behaviour change. Methods: Quasi-experimental analyses in a cohort study of 450 commuters exposed to a new guided busway with a path for walking and cycling in Cambridge, UK.

  13. Controlling factors of the parental safety perception on children's travel mode choice.

    Science.gov (United States)

    Nevelsteen, Kristof; Steenberghen, Thérèse; Van Rompaey, Anton; Uyttersprot, Liesbeth

    2012-03-01

    The travel mode of children changed significantly over the last 20 years, with a decrease of children travelling as pedestrians or cyclists. This study focuses on six to twelve year old children. Parents determine to a large extent the mode choice of children in this age category. Based on the analysis of an extensive survey, the research shows that traffic infrastructure has a significant impact on parental decision making concerning children's travel mode choice, by affecting both the real and the perceived traffic safety. Real traffic safety is quantified in terms of numbers of accidents and road infrastructure. For the perceived traffic safety a parental allowance probability is calculated per road type to show that infrastructure characteristics influence parental decision making on the children's mode choice. A binary logistic model shows that this allowance is determined by age, gender and traffic infrastructure near the child's home or near destinations frequently visited by children. Since both real and perceived traffic safety are influenced by infrastructure characteristics, a spatial analysis of parental perception and accident statistics can be used to indicate the locations where infrastructure improvements will be most effective to increase the number of children travelling - safely - as pedestrians or cyclists. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Shippers’ Choice Behaviour in Choosing Transport Mode: The Case of South East Asia (SEA Region

    Directory of Open Access Journals (Sweden)

    Chia-Hsun Chang

    2017-12-01

    Full Text Available Using South East Asia as a case study, shippers’ choice of transport modes taking into consideration their economic and environmental impacts was examined in this research. A triangulation of both quantitative and qualitative methods was deployed. First, a quantitative analysis using secondary data was conducted to establish the index score, which includes four quantitative factors (transport distance, cost, time, and CO2 emission, for each transport mode. In addition, in order to examine at what level of the importance weight shippers would change their decision on transport mode, a sensitivity analysis involving the four aforesaid factors was also conducted. Next, an in-depth interview with a major shipper in Singapore was also carried out to qualitatively validate the aforesaid four quantitative factors as well as two additional qualitative factors, namely, customer service and shipper-forwarder relationship in relation to shipper's choice. The results from this study indicate that shippers might change to the short-sea shipping (SSS mode when the importance weights of cost and CO2 emission increase, and to trucking mode when the weight of time decreases. It was also found that cost is the most important factor when shippers choose carriers/forwarders, whereas CO2 emission is not an important factor at the current stage. However, if the government imposes financial measures such as fine and/or tax for CO2 emission, shippers would choose eco-friendlier transport modes. This research is the first study considering the environmental issue as one of important factors that influence shippers’ choice behaviour. This research also facilitates managers’ understanding on how shippers may select LSPs taking into account important factors including the environmental consideration.

  15. The commuting time paradox

    NARCIS (Netherlands)

    van Ommeren, J.N.; Rietveld, P.

    2005-01-01

    We examine the conditions for the 'commuting time paradox' which states that the average commuting time does not vary between different periods. We develop therefore an equilibrium job search model with endogenously chosen commuting costs. Presuming wage bargaining between workers and firms, the

  16. Modeling mode choice behavior incorporating household and individual sociodemographics and travel attributes based on rough sets theory.

    Science.gov (United States)

    Cheng, Long; Chen, Xuewu; Wei, Ming; Wu, Jingxian; Hou, Xianyao

    2014-01-01

    Most traditional mode choice models are based on the principle of random utility maximization derived from econometric theory. Alternatively, mode choice modeling can be regarded as a pattern recognition problem reflected from the explanatory variables of determining the choices between alternatives. The paper applies the knowledge discovery technique of rough sets theory to model travel mode choices incorporating household and individual sociodemographics and travel information, and to identify the significance of each attribute. The study uses the detailed travel diary survey data of Changxing county which contains information on both household and individual travel behaviors for model estimation and evaluation. The knowledge is presented in the form of easily understood IF-THEN statements or rules which reveal how each attribute influences mode choice behavior. These rules are then used to predict travel mode choices from information held about previously unseen individuals and the classification performance is assessed. The rough sets model shows high robustness and good predictive ability. The most significant condition attributes identified to determine travel mode choices are gender, distance, household annual income, and occupation. Comparative evaluation with the MNL model also proves that the rough sets model gives superior prediction accuracy and coverage on travel mode choice modeling.

  17. Modeling Mode Choice Behavior Incorporating Household and Individual Sociodemographics and Travel Attributes Based on Rough Sets Theory

    Directory of Open Access Journals (Sweden)

    Long Cheng

    2014-01-01

    Full Text Available Most traditional mode choice models are based on the principle of random utility maximization derived from econometric theory. Alternatively, mode choice modeling can be regarded as a pattern recognition problem reflected from the explanatory variables of determining the choices between alternatives. The paper applies the knowledge discovery technique of rough sets theory to model travel mode choices incorporating household and individual sociodemographics and travel information, and to identify the significance of each attribute. The study uses the detailed travel diary survey data of Changxing county which contains information on both household and individual travel behaviors for model estimation and evaluation. The knowledge is presented in the form of easily understood IF-THEN statements or rules which reveal how each attribute influences mode choice behavior. These rules are then used to predict travel mode choices from information held about previously unseen individuals and the classification performance is assessed. The rough sets model shows high robustness and good predictive ability. The most significant condition attributes identified to determine travel mode choices are gender, distance, household annual income, and occupation. Comparative evaluation with the MNL model also proves that the rough sets model gives superior prediction accuracy and coverage on travel mode choice modeling.

  18. Mode Choice of Undergraduates : A Case Study of Lecture Trips in Nigeria.

    Directory of Open Access Journals (Sweden)

    Moses Olaniran Olawole

    2017-01-01

    Full Text Available Abstract Travel behavior and determinants of mode choice of university students in Nigeria are neither well understood nor well represented in literature. This study model is modal choice of undergraduates, using data from students travel survey and logistic regression to determine factors influence modal choice of undergraduate students in Obafemi Awolowo University Ile-Ife, Nigeria. The results indicate that walking dominate modes for on-campus and commercial bus for off-campus students, while motorcycles taxi is used by few of the sample. Mode choices are influenced by a combination of socio-economic and trip factors. A key finding is extent that these variables positively affect the odds of using walk and commercial bus modes especially with reference to student residence: on and off-campus.  The results suggest investment in pedestrian infrastructure and development of intermodal transport system as a means of making the university livable and attractive. Abstrak Kebiaasaan perjalanan dan penentu moda dari mahasiswa di Nigeria tidak juga dipahami dengan baik atau dijelaskan dalam literatur. Model penelitian ini adalah pemilihan moda mahasiswa menggunakan data dari survei perjalanan mahasiswa dan regresi logistik untuk menentukan faktor penyebab pilihan moda dari mahasiswa di Universitas Obafemi Awolowo, Ile-Ife, Nigeria. Hasilnya menunjukkan berjalan mendominasi pilihan untuk ke kampus dan kendaraan bus umum untuk mahasiswa di luar kampus, sementara sepeda motor taksi digunakan oleh beberapa sample. Pilihan cara dipengaruhi oleh kombinasi dari sosial-ekonomi dan faktor kunjungan. Inti penelitian adalah luasnya variabel positif mempengaruhi peluang dari berjalan dan kendaraan bus umum terutama rujukan ke asrama mahasiswa, dalam maupun luar kampus. Hasil penelitian menyarankan investasi pada infrastruktur pejalan kaki dan pengembangan dari sistem transportasi antarmoda sebagai sarana membuat universitas layak huni dan menarik.

  19. Commuting patterns of workers in a village of Barddhaman district, West Bengal

    Directory of Open Access Journals (Sweden)

    Bhaswati Mondal

    2015-06-01

    Full Text Available Commuting helps to keep balance between residence and workplace of workers. With growing accessibility and connectivity, the importance of commuting is increasing all over the world. It is becoming a major substitute to migration. In commute-studies, commute-pattern is an important chapter. It highlights commuters’ directions of movement, distance they cover, modes of transport they use, the time they take to commute, etc. Unlike the urban-based commute pattern, commute pattern in rural areas are relatively an under-researched issue. In fact, traditionally rural people are thought to carry a sedentary lifestyle. Using primary data, this study aims to explore the commute patterns of rural workers located in the village of Gandharbapur of Barddhaman district of West Bengal, India. All the commuters were found to be engaged in non-farm work. Commuters stem from two major groups. One group of commuters is accumulated farm-income induced. They possess sufficient agricultural land. Investing their surplus farm-income, they have established non-farm works. The second group of commuters is poverty-driven. They are landless poor or are marginal farmers and to escape poverty, they have slipped into these works. Located beyond the suburban area (Memari being the nearest town, most commuters commute to nearby rural areas. Due to non-availability of public transport, women commute less than men do. Regular-paid government employees commute longer than other workers commute. The article concludes with a summary of findings and recommendations for further research.

  20. Internet and telephonic IVR mixed-mode survey for longitudinal studies: choice, retention, and data equivalency.

    Science.gov (United States)

    Verma, Santosh K; Courtney, Theodore K; Lombardi, David A; Chang, Wen-Ruey; Huang, Yueng-Hsiang; Brennan, Melanye J; Perry, Melissa J

    2014-01-01

    This study examined data equivalency and loss to follow-up rates from Internet and interactive voice response (IVR) system surveys in a prospective-cohort study. 475 limited-service restaurant workers participating in the 12-week study were given a choice to report their weekly slipping experience by either IVR or Internet. Demographic differences, loss to follow-up, self-reported rates of slipping, and selection of first and last choices were compared. Loss to follow-up rates were slightly higher for those choosing the IVR mode. Rates of slipping and selection of first and last choices were not significantly different between survey modes. Propensity to choose an Internet survey decreased with increasing age, and was the lowest among Spanish speakers (5%) and those with less than a high school education (14%). Studies relying solely on Internet-based data collection may lead to selective exclusion of certain populations. Findings suggest that Internet and IVR may be combined as survey modalities within longitudinal studies. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Commuting behaviour and urban form: a longitudinal study of a polycentric urban region in Denmark

    DEFF Research Database (Denmark)

    Grunfelder, Julien; Nielsen, Thomas Alexander Sick

    2012-01-01

    This paper is an empirical investigation of the relation between urban form and commuting behaviour in a polycentric urban region. It explores to what extent urban form and location variables help to explain commuting time, distance and mode based on an empirical case, East Jutland, which....... For instance, two of the important findings are that the distance to the closest urban centre is an important factor which affects the three selected aspects of commuting, while the distance from the residence to the closest large city (i.e. second-ranked city) is associated with a relatively short commuting...... selected aspects of commuting. However, urban form variables have greater explanatory power in explaining commuting modes than commuting time and commuting distance. No general trends in commuting were detectable from the data. Finally, the empirical findings revealed specificities of the case study...

  2. Choice of Artificial Ventilation Mode in Premature Neonates with Respiratory Distress Syndrome

    Directory of Open Access Journals (Sweden)

    S. A. Perepelitsa

    2010-01-01

    Full Text Available Objective: to choose an artificial ventilation (AV mode in premature neonates with respiratory distress syndrome (RDS after administration of exogenous surfactants and to compare the duration of AV and the development of complications in relation to the type of an exogenous surfactant. Subjects and methods. The paper presents the results of choosing an AV mode in 122 premature neonates with severe RDS. The choice of an AV mode, the duration of respiratory therapy, and the development of complications after administration of exogenous surfactants were studied. The neonatal infants were divided into 2 groups: 1 55 neonates who were given Surfactant BL in the complex therapy of RDS; 2 67 neonates who received Curosurf. Results. The study has demonstrated that the initial mode of ventilation (completely controlled assisted or positive end expiratory pressure may be chosen after administration of Curosurf depending on the clinical picture of remaining respiratory failure. This policy makes it possible to preserve spontaneous breath in 29.3% of cases and to considerably reduce the duration of respiratory therapy. When Surfactant BL is used, only one initial AV mode (completely controlled ventilation may be chosen according to the manufacturer’s guidelines as drug-induced cessation of spontaneous breathing is required. Nevertheless, the administration of Surfactant BL also facilitates recovery of effective spontaneous breathing in most neonates with RDS. Conclusion. The use of the exogenous surfactants enables the AV modes with preserved spontaneous breathing to be employed, which reduces the duration of AV and the number of complications. Key words: respiratory distress syndrome, premature neonates, Curosurf, Surfactant BL, artificial ventilation modes.

  3. Neighborhood crime and travel behavior : an investigation of the influence of neighborhood crime rates on mode choice, phase II.

    Science.gov (United States)

    2012-01-01

    There are considerable environmental and public health benefits if people choose to walk, bicycle, or ride transit, instead of drive. However, little work has been done on the effects of neighborhood crimes on mode choice. Instinctively, we understan...

  4. Neighborhood crime and travel behavior : an investigation of the influence of neighborhood crime rates on mode choice - phase II.

    Science.gov (United States)

    2012-01-01

    There are considerable environmental and public health benefits if people choose to walk, bicycle, or ride transit, instead of drive. : However, little work has been done on the effects of neighborhood crimes on mode choice. Instinctively, we underst...

  5. Estimation of EVA Mode Choice Model Parameters with Different Types of Utility Functions

    Directory of Open Access Journals (Sweden)

    Tomaž Maher

    2011-05-01

    Full Text Available This paper presents the estimation of nine types of utility function parameters for the application in EVA mode choice model for the city of Ljubljana, Slovenia. Four different modes (private car, public transport, bike and walking and five purposes (work, education, shopping, leisure and other were taken into consideration. This paper presents first the design of the Stated Preference survey, then a brief review of the EVA model, different types of utility functions and the estimation method. The final log-likelihood enables comparison of different types of utility functions. The results show that absolute differences in final log-likelihood among most types of utility functions are not high despite the different shapes, which implies that different functions may best describe different variables.

  6. Model of traffic access mode and railway station choice of suburban railway system in Slovenia

    Directory of Open Access Journals (Sweden)

    Gregor RAK

    2014-12-01

    Full Text Available This article presents the establishment of a model of understanding the access mode and railway station choice of Slovenian passengers. Therefore, a model has been designed to predict the determination of existing decision making preferences of railway users about the access mode and railway station choice with a stated preference survey and face to face method. The target group in the survey were railway passengers in the suburban environment that use the rail for work and school purposes. The total number of respondents was 412. The survey showed that most passengers access the railway station with car (60,2%, by foot (26,2%, with public transport (bus – 8,3% and with bike (5,3%. Average distance to the station is 4,9 km, average time of access is 10,5 min. Upon exit most passengers walk to the final destination (84,5%, use the public transport (bus – 14,1%, car (1,2% or bike (0,2%. Average time from exit of the train to final destination is 13,1 min, average distance is 1,58 km.

  7. Wages and commuting

    DEFF Research Database (Denmark)

    Mulalic, Ismir; Ommeren, Jos N. van; Pilegaard, Ninette

    2011-01-01

    We examine the causal effect of commuting distance on workers' wages in a quasi-natural experiments setting using information on all workers in Denmark. We account for endogeneity of distance by using changes in distance that are due to firms’ relocations. For the range of commuting distances whe...

  8. Relationship between mode choice and the location of supermarkets – empirical analysis in Austria

    Directory of Open Access Journals (Sweden)

    Roman KLEMENTSCHITZ

    2014-03-01

    Full Text Available Main goal of the study work is to gain data about shopping and mobility behaviour at small local supermarkets with sales floor space less than 1.000 m2. Four location types have been defined and discussed; rural  peripheral location, rural  central location, urban – central location and urban – peripheral location. 200 shoppers each location were interviewed at the exit of the supermarket, which means a total of 800 interviews were carried out during all day times and working days of the supermarket. As expected, the mode choice is strongly dependent on the location of the supermarket. In car oriented settlements, which can be found at rural peripheral locations, nearly all shoppers accessed the supermarket with their cars. If weighting the expenditure per visit with the frequency of visits, the average expenditure per month and mode can be derived. The average purchase per month between the modes is more or less balanced. A difference in behaviour lies in the fact that cyclists and pedestrians go shopping more frequently but are spending less per visit. Additionally, the results of this study are indicating the existence of a potential mode shift, especially if there is better land use planning for supermarket locations. Furthermore, considering the given situation and a given threshold of less than 5 kilograms of weight of the goods purchased, more than fifty percent of all shoppers could use non motorised modes with insignificant loss of travel quality. Combined with short travel distances to the next shop (the average distance is 4.9 km, a change to alternative means of transport would be relatively easy for a significant number of shoppers.

  9. A hybrid discrete choice model to assess the effect of awareness and attitude towards environmentally friendly travel modes

    DEFF Research Database (Denmark)

    Sottile, Eleonora; Meloni, Italo; Cherchi, Elisabetta

    2015-01-01

    The need to reduce private vehicle use has led to the development of soft measures aimed at re-educating car users through information processes that raise their awareness regarding the benefits of environmentally friendly modes, encouraging them to voluntarily change their mode choice behaviour...... are not sufficient to overcome the effect of cognitive dissonance, one of the main factors hindering change. In fact it is not unusual to find discrepancies between attitudes and behaviour in travel behaviour research. The objective of the present work is to understand the relationship between awareness, attitude......&R) instead of their car, we estimated a hybrid mode choice model....

  10. Determining Commuting Behaviour from Monitoring Technologies

    Directory of Open Access Journals (Sweden)

    Yuting You

    2015-01-01

    Full Text Available The study of commuting behaviour has always been one significant focus of people to reach comprehensive knowledge of transport-related scenarios. Similarly, commuting behaviour, as one of the four major physical activities people engaged in during daily life, gained much attention in aspect of health fields. This paper, with the sample data collected by The Australian Diabetes, Obesity and Lifestyle (AusDiab study, discusses the process of how to utilize data obtained from GPS and inclinometer device, along with basic information about participants to conduct travel survey, and reconstructing participant's commuting behaviour. In the analyses of the sample, the procedure of datasets integration through DELPHI programming and protocols established to determine corresponding commuting behaviour are discussed. The details of commuting behaviour illustrated in this study included travel mode, travel duration, allocation of trip stages, and corresponding level of physical activities. This paper discusses a promise for applying advanced technologies in travel survey instead of traditional ones in terms of accuracy and reliability; it discusses the feasibility to discover the coherent relationship between health outcome and commuting behaviour from travel-tracking technologies.

  11. Sustainable Commuting @Work

    Directory of Open Access Journals (Sweden)

    S. Castellani

    2014-10-01

    Full Text Available Local governments are seeking effective ways to promote sustainable commuting for reducing energy consumption and improving commuters’ experience. They often use so-called “Workplace Travel Plans” as policy interventions to engage work organizations as active players, promoting sustainable commuting amongst their employees. However, it remains difficult to systematically engage work organizations and commuters in such efforts for a number of reasons, ranging from preferences to constraints that they have to deal with. We aim at providing commuters, work organizations, and public administrators with tools that facilitate this engagement. In this paper, we discuss the requirements for the design of technology supporting corresponding services for commuters and work organizations and we shortly illustrate the infrastructure that we are developing to provide such services.

  12. Mode choice models' ability to express intention to change travel behaviour considering non-compensatory rules and latent variables

    Directory of Open Access Journals (Sweden)

    Nobuhiro Sanko

    2013-03-01

    Full Text Available Disaggregate behaviour choice models have been improved in many aspects, but they are rarely evaluated from the viewpoint of their ability to express intention to change travel behaviour. This study compared various models, including objective and latent models and compensatory and non-compensatory decision-making models. Latent models contain latent factors calculated using the LISREL (linear structural relations model. Non-compensatory models are based on a lexicographic-semiorder heuristic. This paper proposes ‘probability increment’ and ‘joint probability increment’ as indicators for evaluating the ability of these models to express intention to change travel behaviour. The application to commuting travel data in the Chukyo metropolitan area in Japan showed that the appropriate non-compensatory and latent models outperform other models.

  13. Analysis of Socio-spatial Differentiation in Transport Mode Choice Preferences

    Directory of Open Access Journals (Sweden)

    Geran-Marko Miletić

    2017-04-01

    Full Text Available Starting from the fact that the transport mode choice is one of those aspects of travel behaviour that, to a great extent, affects the efficiency of the transport system, this paper analyses the factors that contribute to the use of public and car transport. The goals of the analysis were to obtain insight into the preferences for using these two modes of transport in Croatia and find out to which extent the basic demographic and socioeconomic characteristics of the respondents affect the usage of car and public transport and the possibility of taking trips by these transport modes. The paper analyses the data collected by surveys on a representative national sample. The results show that in Croatia, the number of people who frequently use public transport is far fewer than the number of frequent users of passenger car transport. However, the comparison has found that the number of frequent public transport users varies significantly among certain categories of respondents. Using binary logistic regression analysis has determined that the preferences towards the frequent use of car or public transport are significantly influenced by the age of the respondents, size of the settlement, accessibility of the destinations by public transport, the number of vehicles in the household and whether the respondent is the main car user in the household.

  14. Discrete-choice modelling of patient preferences for modes of drug administration.

    Science.gov (United States)

    Tetteh, Ebenezer Kwabena; Morris, Steve; Titcheneker-Hooker, Nigel

    2017-12-01

    The administration of (biologically-derived) drugs for various disease conditions involves consumption of resources that constitutes a direct monetary cost to healthcare payers and providers. An often ignored cost relates to a mismatch between patients' preferences and the mode of drug administration. The "intangible" benefits of giving patients what they want in terms of the mode of drug delivery is seldom considered. This study aims to evaluate, in monetary terms, end-user preferences for the non-monetary attributes of different modes of drug administration using a discrete-choice experiment. It provides empirical support to the notion that there are significant benefits from developing patient-friendly approaches to drug delivery. The gross benefits per patient per unit administration is in the same order of magnitude as the savings in resource costs of administering drugs. The study argues that, as long as the underlying manufacturing science is capable, a patient-centred approach to producing drug delivery systems should be encouraged and pursued.

  15. Organisation of maternity care and choices of mode of birth: a worldwide view.

    Science.gov (United States)

    Soltani, Hora; Sandall, Jane

    2012-04-01

    Drawing on the findings from a Cochrane systematic review of midwife-led care vs. other models of maternity care, this article discusses maternity organisation of care, women's choice of mode of birth and a global trend in reducing normality of childbirth. The review included 11 trials involving 12,276 women. The results showed that women who received models of midwife led care were less likely to experience fetal loss before 24 weeks' gestation, less likely to have regional analgesia, less likely to have instrumental birth, less likely to have an episiotomy (with no significant differences in perineal lacerations), and were more likely to be attended at birth by a known midwife, more likely to have a spontaneous vaginal birth, initiate breast feeding and more stated to feel in control. In addition, their babies were more likely to have a shorter length of hospital stay. No statistically significant differences were observed in fetal loss/neonatal death of at least 24 weeks or in overall fetal/neonatal death between women who were allocated to the midwifery led care and those in the medical led care. In light of these findings, the interrelationship between social organisation of maternity care, philosophy of care and choice is explored using case examples with high and low rates of caesarean section rates. A worldwide overview of vaginal birth and caesarean section rates as indicators of normality (and lack of it) is also presented. Questions are raised with regard to the fast growing rate of caesarean section rates particularly among middle income countries. The rate of caesarean section is twice as much in private settings compared to public hospitals in these countries. In conclusion, the importance of sharing good practice among countries with particular attention to social location of midwifery, mobilisation of consumer groups as well as education of maternity health-care professionals and women, in facilitation of an effective 'informed choice', is

  16. Transport-related lifestyle and environmentally-friendly travel mode choices: A multi-level approach

    DEFF Research Database (Denmark)

    Thøgersen, John

    2018-01-01

    This paper introduces a deductive cognitive approach to, and a new instrument for measuring, transport-related lifestyle (TRL) and presents a first application of the instrument for identifying national and cross-national transport-related lifestyle segments based on a survey (N = 3216) in 10...... European countries. Principal component analysis is used to reduce the TRL instrument’s 69 items to 18 dimensions within five lifestyle components. Based on multi-group confirmatory factor analysis, it is found that the instrument possesses metric, but not scalar (measurement) invariance across the 10....... Finally, a multivariate GLM analysis reveals that three behavioral tendencies of importance for transport-related environmental impacts vary significantly and substantially between lifestyle segments: vehicle ownership, everyday travel-mode choice and environmentally-friendly transport innovativeness...

  17. Integrated Mode Choice, Small Aircraft Demand, and Airport Operations Model User's Guide

    Science.gov (United States)

    Yackovetsky, Robert E. (Technical Monitor); Dollyhigh, Samuel M.

    2004-01-01

    A mode choice model that generates on-demand air travel forecasts at a set of GA airports based on changes in economic characteristics, vehicle performance characteristics such as speed and cost, and demographic trends has been integrated with a model to generate itinerate aircraft operations by airplane category at a set of 3227 airports. Numerous intermediate outputs can be generated, such as the number of additional trips diverted from automobiles and schedule air by the improved performance and cost of on-demand air vehicles. The total number of transported passenger miles that are diverted is also available. From these results the number of new aircraft to service the increased demand can be calculated. Output from the models discussed is in the format to generate the origin and destination traffic flow between the 3227 airports based on solutions to a gravity model.

  18. Understanding repetitive travel mode choices in a stable context: A panel study approach

    DEFF Research Database (Denmark)

    Thøgersen, John

    2006-01-01

    It is argued that most travel mode choices are repetitive and made in a stable context. As an example, the everyday use of public transport is analyzed based on a panel survey with a random sample of about 1300 Danish residents interviewed up to three times in the period 1998-2000. The use...... of public transport is traced back to attitudes towards doing so, beliefs about whether or not public transportation can cover one's transport needs, and car ownership. The influence of these variables is greatly attenuated when past behavior is accounted for, however. For subjects without a car, behavior...... changes are in the direction of greater consistency with current attitudes and perceptions. For car owners, current attitudes are inconsequential. The temporal stability of transport behavior is also higher for car-owners than for non-owners....

  19. Influencing Mechanism of Potential Factors on Passengers’ Long-Distance Travel Mode Choices Based on Structural Equation Modeling

    Directory of Open Access Journals (Sweden)

    Yun Wang

    2017-10-01

    Full Text Available Understanding the public transportation users’ preferences to long-distance travel modes would contribute to reasonable developing policies and resource allocation. This paper aims to explore the influencing mechanism of potential factors on the long-distance travel mode choice. A survey was conducted to collect the data. The analysis of variance (ANOVA approach was applied to analyze the correlation relationship between potential factors and travel mode choice behavior. The results showed that, except gender, service demand for safety and departure time, all of the other factors significantly influenced the travel mode choice behavior. Specifically, passengers with higher education level and income level were more likely to choose high-speed railway (HSR and plane; passengers caring about travel expense were more likely to choose ordinary train, whereas plane and HSR may be chosen more by passengers caring more about comfort, punctuality and efficiency; the more passengers were satisfied with travel modes’ service performance, the more they would be likely to choose them; the most competitive distance ranges for coach, ordinary train, HSR and plane were below 500 km, 500–1000 km, 500–1500 km and over 1500 km, respectively. Besides, the structural equation modeling (SEM technique was applied to investigate the influencing mechanism of factors on the long-distance travel mode choice. The results revealed that travel distance was the most significant variable directly influencing passengers’ mode choices, followed by the service demand, performance evaluation, and personal attributes. Furthermore, personal attributes were verified to have an indirect effect on travel mode choice behavior by significantly affecting the service demand and performance evaluation.

  20. Choice of Anesthesia Mode, Neuroprotective Therapy in the Surgical Repair of Extracranial Vessels

    Directory of Open Access Journals (Sweden)

    M. I. Neimark

    2011-01-01

    Full Text Available Objective: to improve the direct results of carotid endarterectomy, by reducing the number of perioperative complications via the choice of an anesthesia mode and a neuroprotective regimen for possible neurological complications. Subjects and methods. Total intravenous diprivan anesthesia versus regional cervical plexus anesthesia after Pashchuk and inhaled sevorane anesthesia was evaluated in 190 patients with carotid endarterectomy. The parameters of cerebral blood flow and the markers for brain damage were studied. Results. Sevorane anesthesia has been shown to maintain optimal cerebral blood flow, which limits ischemia and reperfusion brain damages and results in fewer postoperative complications. Neurological disorders were an indication for neuroprotective therapy and, according to which, the patients were divided into 2 matched groups. Therapy with mexidol and cytoflavin, which had already become traditional, was used in Group 1. Group 2 patients were given the current neuroprotective agent citicoline (ceraxone with actovegin. The performed trials showed that the neuroprotective therapy used in Group 2 was more effective (5% significance level than that in Group 1. Conclusion. Inhalational sevorane anesthesia versus total intravenous diprivan anesthesia and regional cervical plexus anesthesia is characterized by optimal cerebral blood flow values, less neuronal damage, and fewer postoperative neurological complications. Irrespective of the mode of anesthesia, neuroprotective therapy involving ceraxone in combination with actovegin is preferred for the intensive therapy of postoperative neurological disorders. Key words: diprivan, sevorane, neuron-specific enolase, linear cerebral blood flow velocity, carotid endarterectomy, cerebral perfusion pressure, brain-specific protein antibodies, ceraxone.

  1. The impact of attitudes and perceptions on travel mode choice and car ownership in a Chinese megacity

    DEFF Research Database (Denmark)

    He, Sylvia Y.; Thøgersen, John

    2017-01-01

    The objective of this research is to understand intentions to buy a car and how car-ownership, together with other personal, situational and attitudinal factors, influences travel mode choice in a Chinese megacity. A survey was carried out in Guangzhou, China to examine respondents’ car ownership...... and travel mode perceptions and choices, as well as personal and situational characteristics. A quota sampling procedure was used to select members of three different groups: car owners; no car but planning to buy one in the next 5 years – car intenders; and no car and not planning to buy one. We find...... that car ownership is the most important among included predictors of travel mode choice, which also depend on other personal and situational factors, but only indirectly by attitudinal factors. However, attitudinal factors have a strong impact on the intention to buy a car, while controlling for other...

  2. Commuting Pattern with Park-and-Ride Option for Heterogeneous Commuters

    Directory of Open Access Journals (Sweden)

    Chengjuan Zhu

    2013-01-01

    Full Text Available We study the effect of the parking on heterogeneous commuters' travel choice in a competitive transportation system which consists of a subway and a parallel road with a bottleneck of limited service capacity. Every morning, commuters either use their private cars only or drive their cars to the bottleneck, park there, and then take the subway to the destination. Considering the effects caused by body congestion in carriage and the parking fees, we developed a bottleneck model to describe the commuters' travel choice. There exist several types of equilibrium that corresponds to user equilibrium. We investigated the influence of the capacity of the bottleneck and the total travel demand on the travel behaviors and on the total social cost. It is shown that there exists a scheme with suitable subway fare and parking fees to implement the minimum total social cost.

  3. Commuter Survey-2014

    Data.gov (United States)

    US Agency for International Development — This dataset is the USAID portion of a larger dataset developed by OMB to better understand and to quanity the carbon footprint of the daily commute of government...

  4. Wages and commuting

    DEFF Research Database (Denmark)

    Mulalic, Ismir; Ommeren, Jos N. van; Pilegaard, Ninette

    2011-01-01

    We examine the causal effect of commuting distance on workers' wages in a quasi-natural experiments setting using information on all workers in Denmark. We account for endogeneity of distance by using changes in distance that are due to firms’ relocations. For the range of commuting distances where...... income tax reductions associated with commuting do not apply, one kilometre increase in commuting distance induces a wage increase of about 0.42%, suggesting an hourly compensation of about half of the hourly net wage. Our findings are consistent with wage bargaining theory and suggest a bargaining power...... parameter of about 0.50. Due to the experimental setup we are able to exclude many competing explanations of the wage-distance relationship....

  5. Variability in baseline travel behaviour as a predictor of changes in commuting by active travel, car and public transport: a natural experimental study.

    Science.gov (United States)

    Heinen, Eva; Ogilvie, David

    2016-03-01

    To strengthen our understanding of the impact of baseline variability in mode choice on the likelihood of travel behaviour change. Quasi-experimental analyses in a cohort study of 450 commuters exposed to a new guided busway with a path for walking and cycling in Cambridge, UK. Exposure to the intervention was defined using the shortest network distance from each participant's home to the busway. Variability in commuter travel behaviour at baseline was defined using the Herfindahl-Hirschman Index, the number of different modes of transport used over a week, and the proportion of trips made by the main (combination of) mode(s). The outcomes were changes in the share of commute trips (i) involving any active travel, (ii) involving any public transport, and (iii) made entirely by car. Variability and change data were derived from a self-reported seven-day record collected before (2009) and after (2012) the intervention. Separate multinomial regression models were estimated to assess the influence of baseline variability on behaviour change, both independently and as an interaction effect with exposure to the intervention. All three measures of variability predicted changes in mode share in most models. The effect size for the intervention was slightly strengthened after including variability. Commuters with higher baseline variability were more likely to increase their active mode share (e.g. for HHI: relative risk ratio [RRR] for interaction 3.34, 95% CI 1.41, 7.89) and decrease their car mode share in response to the intervention (e.g. for HHI: RRR 7.50, 95% CI 2.52, 22.34). People reporting a higher level of variability in mode choice were more likely to change their travel behaviour following an intervention. Future research should consider such variability as a potential predictor and effect modifier of travel and physical activity behaviour change, and its significance for the design and targeting of interventions.

  6. Computational commutative and non-commutative algebraic geometry

    CERN Document Server

    Cojocaru, S; Ufnarovski, V

    2005-01-01

    This publication gives a good insight in the interplay between commutative and non-commutative algebraic geometry. The theoretical and computational aspects are the central theme in this study. The topic is looked at from different perspectives in over 20 lecture reports. It emphasizes the current trends in commutative and non-commutative algebraic geometry and algebra. The contributors to this publication present the most recent and state-of-the-art progresses which reflect the topic discussed in this publication. Both researchers and graduate students will find this book a good source of information on commutative and non-commutative algebraic geometry.

  7. Exploring Multiple Motivations on Urban Residents’ Travel Mode Choices: An Empirical Study from Jiangsu Province in China

    Directory of Open Access Journals (Sweden)

    Jichao Geng

    2017-01-01

    Full Text Available People’s actions are always accompanied with multiple motives. How to estimate the role of the pro-environment motivation under the interference of other motivations will help us to better interpret human environmental behaviors. On the basis of classical motivation theories and travel mode choice research backgrounds, the concepts of pro-environmental and self-interested motivation were defined. Then based on survey data on 1244 urban residents in the Jiangsu Province in China, the multinomial logistic regression model was constructed to examine the effects of multiple motivations, government measures, and demographic characteristics on residents’ travel mode choice behaviors. The result indicates that compared to car use, pro-environmental motivation certainly has a significant and positive role in promoting green travel mode choices (walking, bicycling, and using public transport, but this unstable green behavior is always dominated by self-interested motivations rather than the pro-environmental motivation. In addition, the effects of gender, age, income, vehicle ownership, travel distance, and government instruments show significant differences among travel mode choices. The findings suggest that pro-environmental motivation needs to be stressed and highlighted to ensure sustainable urban transportation. However, policies aimed to only increase the public awareness of environment protection are not enough; tailored policy interventions should be targeted to specific groups having different main motivations.

  8. A dynamic framework on travel mode choice focusing on utilitarian walking based on the integration of current knowledge.

    Science.gov (United States)

    Yang, Yong

    2016-09-01

    Recently, research on utilitarian walking has gained momentum due to its benefits on both health and the environment. However, our overall understanding of how built and social environments affect travel mode choice (walking or not) is still limited, and most existing frameworks on travel mode choice lack dynamic processes. After a review of several mainstream theories and a number of frameworks, we propose an integrated framework. The basic constructs in the travel mode choice function are utilities, constraints, attitudes, and habits. With a hierarchical structure and heuristic rules, the travel mode choice function is modified by individual characteristics and travel characteristics. The framework explicitly presents several dynamic processes, including the perception process on the environment, attitude formation process, habit formation process, interactions among an individual's own behaviors, interactions among travelers, feedback from travel to the built and social environments, and feedback from other behaviors to the built and social environments. For utilitarian walking, the framework may contribute to the study design, data collection, adoption of new research methods, and provide indications for policy interventions.

  9. The Determinants of Transportation Mode Choice in the Middle Eastern Cities: the Kerman Case, Iran

    Directory of Open Access Journals (Sweden)

    Hamid Soltanzadeh

    2014-07-01

    Full Text Available Having a precise understanding of the determinants of transportation mode choices and decisions can be under the influence of regional and cultural aspects. This paper outlines such determinants in the Iranian city of Kerman as a representative of the similar Middle Eastern cities located in hot-arid climates and Moslem cultures. The descriptive analysis of the results derived from a short survey that was a part of a larger study conducted in the second half of 2013 indicated that adding to accessibility to public transportation and the convenience of using it can persuade people to shift from car driving to public transit use. The main barriers to bicycling are socio-cultural aspects, while for walking the obstacles are physical and objective. Increasing the quality of pedestrian infrastructure and spaces is a stronger deterrent than personal attitudes against walking. Such findings show slight dissimilarities from the results of some of the western studies that find the built environment more effective. These findings can be a general guide for the Middle Eastern planners to promote walking, biking, and public transport use.

  10. Consumer Behavior in the Choice of Mode of Transport: A Case Study in the Toledo-Madrid Corridor.

    Science.gov (United States)

    Muro-Rodríguez, Ana I; Perez-Jiménez, Israel R; Gutiérrez-Broncano, Santiago

    2017-01-01

    Within the context of the consumption of goods or services the decisions made by individuals involve the choice between a set of discrete alternatives, such as the choice of mode of transport. The methodology for analyzing the consumer behavior are the models of discrete choice based on the Theory of Random Utility. These models are based on the definition of preferences through a utility function that is maximized. These models also denominated of disaggregated demand derived from the decision of a set of individuals, who are formalized by the application of probabilistic models. The objective of this study is to determine the behavior of the consumer in the choice of a service, namely of transport services and in a short-distance corridor, such as Toledo-Madrid. The Toledo-Madrid corridor is characterized by being short distance, with high speed train available within the choice options to get the airport, along with the bus and the car. And where offers of HST and aircraft services can be proposed as complementary modes. By applying disaggregated transport models with revealed preference survey data and declared preferences, one can determine the most important variables involved in the choice and determine the arrangements for payment of individuals. These payment provisions may condition the use of certain transport policies to promote the use of efficient transportation.

  11. Consumer Behavior in the Choice of Mode of Transport: A Case Study in the Toledo-Madrid Corridor

    Directory of Open Access Journals (Sweden)

    Ana I. Muro-Rodríguez

    2017-06-01

    Full Text Available Within the context of the consumption of goods or services the decisions made by individuals involve the choice between a set of discrete alternatives, such as the choice of mode of transport. The methodology for analyzing the consumer behavior are the models of discrete choice based on the Theory of Random Utility. These models are based on the definition of preferences through a utility function that is maximized. These models also denominated of disaggregated demand derived from the decision of a set of individuals, who are formalized by the application of probabilistic models. The objective of this study is to determine the behavior of the consumer in the choice of a service, namely of transport services and in a short-distance corridor, such as Toledo-Madrid. The Toledo-Madrid corridor is characterized by being short distance, with high speed train available within the choice options to get the airport, along with the bus and the car. And where offers of HST and aircraft services can be proposed as complementary modes. By applying disaggregated transport models with revealed preference survey data and declared preferences, one can determine the most important variables involved in the choice and determine the arrangements for payment of individuals. These payment provisions may condition the use of certain transport policies to promote the use of efficient transportation.

  12. Commuting, Exercise and Sport

    DEFF Research Database (Denmark)

    Larsen, Jonas

    2018-01-01

    The uniqueness of this article is that it deals with long-distance bike commuting in pro-cycling Copenhagen and its environs. Informed by practice theory and sensuous studies of urban and sport practices, I discuss the ‘things and environments’, ‘meanings’ and ‘competences and biological bodies......’ that typify long-distance commuter cycling. This article develops cycling literature and the ‘mobilities paradigm’ in the following ways: by outlining a practice approach to cycling; challenging the idea that commuter cycling is only for short distances; undermining the distinction between utility and sport...... cycling; and lastly by connecting the ‘mobilities paradigm’ with literature on active travel and sport studies....

  13. Non-commutative analysis

    CERN Document Server

    Jorgensen, Palle

    2017-01-01

    The book features new directions in analysis, with an emphasis on Hilbert space, mathematical physics, and stochastic processes. We interpret 'non-commutative analysis' broadly to include representations of non-Abelian groups, and non-Abelian algebras; emphasis on Lie groups and operator algebras (C* algebras and von Neumann algebras.)A second theme is commutative and non-commutative harmonic analysis, spectral theory, operator theory and their applications. The list of topics includes shift invariant spaces, group action in differential geometry, and frame theory (over-complete bases) and their applications to engineering (signal processing and multiplexing), projective multi-resolutions, and free probability algebras.The book serves as an accessible introduction, offering a timeless presentation, attractive and accessible to students, both in mathematics and in neighboring fields.

  14. The Choice of Foreign Market Entry Modes: The Role of Resources and Industrial Driving Forces

    Directory of Open Access Journals (Sweden)

    Andrea S. GUBIK

    2014-03-01

    Full Text Available The objective of the paper is to analyse the effects of corporate resources, attitudes  of  owner/entrepreneur/manager  to  internationalisation  and  the characteristics of the business industry on the entry mode choice. Based  on  factor  and  cluster  analyses  the  authors highlight the latent structure lying behind different variables and find typical groups of companies matching the identified factors. Providing  physical  resources  and  access  to  appropriate  information  is necessary,  but  not  sufficient.  The  attitude  of  the  owner/entrepreneur/manager  to internationalisation  should  be  improved  as  well  so  that  they  will  be  able  to  appear and operate successfully in international markets. Giving  the  right  place  to  subjective  matters  in promoting  internationalisation  may  contribute  to  the  increase  in  corporate participation in different support programs. On the basis of the obtained findings, different waysof how  support  programs  can  promote  the  companies’  international  activities  and strengthen their commitments to achieving higher added values can be defined.

  15. Value of time determination for the city of Alexandria based on a disaggregate binary mode choice model

    Directory of Open Access Journals (Sweden)

    Mounir Mahmoud Moghazy Abdel-Aal

    2017-12-01

    Full Text Available In the travel demand modeling field, mode choice is the most important decision that affects the resulted road congestion. The behavioral nature of the disaggregate models and the associated advantages of such models over aggregate models have led to their extensive use. This paper proposes a framework to determine the value of time (VoT for the city of Alexandria through calibrating a disaggregate linear-in parameter utility-based binary logit mode choice model of the city. The mode attributes (travel time and travel cost along with traveler attributes (car ownership and income were selected as the utility attributes of the basic model formulation which included 5 models. Three additional alternative utility formulations based on the transformation of the mode attributes including relative travel cost (cost divided by income and log (travel time and the combination of the two transformations together were introduced. The parameter estimation procedure was based on the likelihood maximization technique and was performed in EXCEL. Out of 20 models estimated, only 2 models are considered successful in terms of the parameters estimates correct signs and the magnitude of their significance (t-statistics value. The determination of the VoT serves also in the model validation. The best two models estimated the value of time at LE 11.30/hr and LE 14.50/hr with a relative error of +3.7% and +33.0%, respectively, of the hourly salary of LE 10.9/hr. The proposed two models prove to be sensitive to trip time and income levels as factors affecting the choice mechanism. The sensitivity analysis was performed and proved the model with higher relative error is marginally more robust. Keywords: Transportation modeling, Binary mode choice, Parameter estimation, Value of time, Likelihood maximization, Sensitivity analysis

  16. Combinatorial commutative algebra

    CERN Document Server

    Miller, Ezra

    2005-01-01

    Offers an introduction to combinatorial commutative algebra, focusing on combinatorial techniques for multigraded polynomial rings, semigroup algebras, and determined rings. The chapters in this work cover topics ranging from homological invariants of monomial ideals and their polyhedral resolutions, to tools for studying algebraic varieties.

  17. Commutation and Darboux transformation

    Indian Academy of Sciences (India)

    2015-10-20

    Oct 20, 2015 ... http://www.ias.ac.in/article/fulltext/pram/085/05/0869-0880. Keywords. Darboux transformation; nonlinear evolution equations; exact solutions. Abstract. In this paper we show that the Darboux transformation for a large class of nonlinear evolution equations arises due to factorization and commutation.

  18. Methodological considerations in the study of delay discounting in intertemporal choice: A comparison of tasks and modes.

    Science.gov (United States)

    Smith, Carter L; Hantula, Donald A

    2008-11-01

    An experimental comparison of two commonly used delay-discounting procedures (binary choice and fill in the blank) and modes of administration (paper and pencil and computer based) was conducted. Statistically significant main effects were found for task type--steeper discounting was observed in the binary-choice task--but not for mode of administration. As simple evidence of validity, hyperbolic curves consistently provided a better fit to the data than did exponential curves for both tasks. Further, magnitude effects were also observed across conditions. Correlational results varied largely as a function of the discounting index (either k or area under the curve) under consideration. Across the two tasks, discounting indices showed modest levels of reliability [r(AUC) = .33; r(k) = .75]. The findings pointed to refinements for both the methodology and criteria that are used to study delay discounting and raised questions about the commonly assumed relationship between discounting and the construct of impulsivity.

  19. Are commuting and residential mobility decisions simultaneous? : the case of Catalonia (Spain)

    OpenAIRE

    Romaní Fernández, Javier, 1969-; Suriñach Caralt, Jordi; Artís Ortuño, Manuel

    2001-01-01

    In this paper we study the commuting and moving decisions of workers in Catalonia (Spain) and its evolution in the 1986-1996 period. Using a microdata sample from the 1991 Spanish Population Census, we estimate a simultaneous, discrete choice model of commuting and moves, thus indirectly addressing the home and job location decisions. The econometrical framework is a simultaneous, binary probit model with a commute equation and a move equation

  20. Binary choice health state valuation and mode of administration: head-to-head comparison of online and CAPI.

    Science.gov (United States)

    Mulhern, Brendan; Longworth, Louise; Brazier, John; Rowen, Donna; Bansback, Nick; Devlin, Nancy; Tsuchiya, Aki

    2013-01-01

    Health state valuation exercises can be conducted online, but the quality of data generated is unclear. To investigate whether responses to binary choice health state valuation questions differ by administration mode: online versus face to face. Identical surveys including demographic, self-reported health status, and seven types of binary choice valuation questions were administered in online and computer-assisted personal interview (CAPI) settings. Samples were recruited following procedures employed in typical online or CAPI studies. Analysis included descriptive comparisons of the distribution of responses across the binary options and probit regression to explain the propensity to choose one option across modes of administration, controlling for background characteristics. Overall, 422 (221 online; 201 CAPI) respondents completed a survey. There were no overall age or sex differences. Online respondents were educated to a higher level than were the CAPI sample and general population, and employment status differed. CAPI respondents reported significantly better general health and health/life satisfaction. CAPI took significantly longer to complete. There was no effect of the mode of administration on responses to the valuation questions, and this was replicated when demographic differences were controlled. The findings suggest that both modes may be equally valid for health state valuation studies using binary choice methods (e.g., discrete choice experiments). There are some differences between the observable characteristics of the samples, and the groups may differ further in terms of unobservable characteristics. When designing health state valuation studies, the advantages and disadvantages of both approaches must be considered. Copyright © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  1. Incorporating social impact on new product adoption in choice modeing: A case study in green vehicles

    Energy Technology Data Exchange (ETDEWEB)

    He, Lin; Wang, Mingxian; Chen, Wei; Conzelmann, Guenter

    2014-10-01

    While discrete choice analysis is prevalent in capturing consumer preferences and describing their choice behaviors in product design, the traditional choice modeling approach assumes that each individual makes independent decisions, without considering the social impact. However, empirical studies show that choice is social - influenced by many factors beyond engineering performance of a product and consumer attributes. To alleviate this limitation, we propose a new choice modeling framework to capture the dynamic influence from social networks on consumer adoption of new products. By introducing social influence attributes into a choice utility function, social network simulation is integrated with the traditional discrete choice analysis in a three-stage process. Our study shows the need for considering social impact in forecasting new product adoption. Using hybrid electric vehicles as an example, our work illustrates the procedure of social network construction, social influence evaluation, and choice model estimation based on data from the National Household Travel Survey. Our study also demonstrates several interesting findings on the dynamic nature of new technology adoption and how social networks may influence hybrid electric vehicle adoption. (C) 2014 Elsevier Ltd. All rights reserved

  2. Designing Discussion Activities to Achieve Desired Learning Outcomes: Choices Using Mode of Delivery and Structure

    Science.gov (United States)

    Sautter, Pookie

    2007-01-01

    The article provides insights on how the design of discussion activities can be used to facilitate alternative learning objectives in the marketing curriculum. A review of the literature provides insight for making choices with regards to two aspects of discussion design: (a) the choice between face-to-face and online (i.e., threaded bulletin…

  3. Personality and online/offline choices: MBTI profiles and favored communication modes in a Singapore study.

    Science.gov (United States)

    Goby, Valerie Priscilla

    2006-02-01

    This study presents an initial investigation of the degree to which personality, as classified by the four dimensions of the Myers-Briggs Type Indicator (MBTI) affects an individual's choice of online or offline means for conducting social interactions. Results yield some evidence that personality affects choice of online or offline options, with an especially significant correlation between online/offline choices and the dimension of Extraversion and Introversion. Significant results are also seen for the Judging-Perception and Thinking-Feeling dimensions, but the Sensing-iNtuition dimension showed no correlation.

  4. Dynamics in Braess Paradox with Nonimpulsive Commuters

    Directory of Open Access Journals (Sweden)

    Arianna Dal Forno

    2015-01-01

    the individual rationality leads to collective irrationality. In the literature, the dynamics has been analyzed when considering impulsive commuters, i.e., those who switch choice regardless of the actual difference between costs. We analyze a dynamical version of the paradox with nonimpulsive commuters, who change road proportionally to the cost difference. When only two roads are available, we provide a rigorous proof of the existence of a unique fixed point showing that it is globally attracting even if locally unstable. When a new road is added the system becomes discontinuous and two-dimensional. We prove that still a unique fixed point exists, and its global attractivity is numerically evidenced, also when the fixed point is locally unstable. Our analysis adds a new insight in the understanding of dynamics in social dilemma.

  5. SME international entry mode choice and performance : A transaction cost perspective

    NARCIS (Netherlands)

    Brouthers, K.D.; Nakos, G.

    2004-01-01

    Although small and medium sized enterprises (SMEs) account for a significant portion of international trade, little is know about how they make international entry mode decisions. Transaction cost theory has been widely used to study entry mode selection for large firms. Here we apply the theory to

  6. Factors Influencing Students' Choice of Study Mode: An Australian Case Study

    Science.gov (United States)

    Ifenthaler, Dirk; Gosper, Maree; Bailey, Matthew; Kretzschmar, Mandy

    2014-01-01

    Despite the expansion of online and blended learning, as well as open education, little research has been undertaken on what motivates students to enrol in particular study modes at university level. This project addresses this gap in higher education research by exploring the reasons why humanities students choose to study through specific modes.…

  7. Ascertaining women's preferred mode of address and preferred choice of title during pregnancy and childbirth.

    Science.gov (United States)

    Horgan, R; Guha, S; Sullivan, K O; Higgins, J R

    2005-02-01

    To determine how women in pregnancy would like to be addressed and to ascertain their preferred choice of title during pregnancy. A questionnaire was administered to 925 antenatal women. Midwifery and medical staff (183) were invited to respond to a similar questionnaire. The response rate was 71.2% from the survey of pregnant women. The vast majority (82.1%) preferred to be addressed by their first name. Women were in favour of being called 'patient' (32.8%) as their first choice. The staff survey yielded a response rate of 77%. The majority (81.8%) of health professionals preferred to address women by their first name. 'Mother' (28.7%) was the most popular first choice. We conclude that women in pregnancy do have a preference on how they would like to be addressed and this is predominantly by first name. Health professionals also prefer to call pregnant women by their first name. The term 'patient' was the most popular first choice of title of women in pregnancy but the term 'mother' was the preferred choice of the health professionals. Medical staff were more likely to choose 'patient' than midwives.

  8. Commutation relations of operator monomials

    Science.gov (United States)

    Pain, Jean-Christophe

    2013-01-01

    In this short paper, the commutator of monomials of operators obeying constant commutation relations is expressed in terms of anti-commutators. The formula involves Bernoulli numbers or Euler polynomials evaluated in zero. The role of Bernoulli numbers in quantum-mechanical identities such as the Baker-Campbell-Hausdorff formula is emphasized and applications connected to ordering problems as well as to the Ehrenfest theorem are proposed.

  9. Radar channel balancing with commutation

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2014-02-01

    When multiple channels are employed in a pulse-Doppler radar, achieving and maintaining balance between the channels is problematic. In some circumstances the channels may be commutated to achieve adequate balance. Commutation is the switching, trading, toggling, or multiplexing of the channels between signal paths. Commutation allows modulating the imbalance energy away from the balanced energy in Doppler, where it can be mitigated with filtering.

  10. What interventions increase commuter cycling? A systematic review.

    Science.gov (United States)

    Stewart, Glenn; Anokye, Nana Kwame; Pokhrel, Subhash

    2015-08-14

    To identify interventions that will increase commuter cycling. All settings where commuter cycling might take place. Adults (aged 18+) in any country. Individual, group or environmental interventions including policies and infrastructure. A wide range of 'changes in commuter cycling' indicators, including frequency of cycling, change in workforce commuting mode, change in commuting population transport mode, use of infrastructure by defined populations and population modal shift. 12 studies from 6 countries (6 from the UK, 2 from Australia, 1 each from Sweden, Ireland, New Zealand and the USA) met the inclusion criteria. Of those, 2 studies were randomised control trials and the remainder preintervention and postintervention studies. The majority of studies (n=7) evaluated individual-based or group-based interventions and the rest environmental interventions. Individual-based or group-based interventions in 6/7 studies were found to increase commuter cycling of which the effect was significant in only 3/6 studies. Environmental interventions, however, had small but positive effects in much larger but more difficult to define populations. Almost all studies had substantial loss to follow-up. Despite commuter cycling prevalence varying widely between countries, robust evidence of what interventions will increase commuter cycling in low cycling prevalence nations is sparse. Wider environmental interventions that make cycling conducive appear to reach out to hard to define but larger populations. This could mean that environmental interventions, despite their small positive effects, have greater public health significance than individual-based or group-based measures because those interventions encourage a larger number of people to integrate physical activity into their everyday lives. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  11. Factors Affecting of Commuter Migrant Traders Income from Tanah Mas Village to Palembang City

    Directory of Open Access Journals (Sweden)

    Bambang Bemby Soebyakto

    2016-09-01

    Full Text Available This study aimed to analyze the factors that affect the income of migrant traders in the informal sector who do commuting of Tanah Mas village to the Palembang city. This research was done using descriptive quantitative primary data. This research was conducted at the Tanah Mas village. Populations of migrant populations who do commuting are 398 people. Proportional stratified random sampling is selected to determine of sample. Samples are 100 migrants’ commuter traders. Multiple regression analysis was used to measure the effect of independent variables (marital status, number of family, length of work, mode of transportation, type of merchandise, and motivation of commuter traders on the dependent variable (commuter trader income . The study found that marital status, number of family, length of work, mode of transportation, type of merchandise, and motivation commuter traders have significantly affect to migrant income the Tanah Mas village to Palembang city. Partially, the number of family, mode of transportation, and the type of merchandise have significantly affect to commuter traders income, whereas marital status, length of work, and motivation commuter trader have not significantly affect the commuter trader income.

  12. JUSTIFICATION OF THE CHOICE OF STEP MODE MICROWAVE-CONVECTIVE DRYING OF PEARS

    Directory of Open Access Journals (Sweden)

    V. D. Demyanov

    2013-01-01

    Full Text Available Analysis the kinetic regularities stationary regimes of microwave-convective drying pears and differential thermal analysis was performed. As a result of this combined rational mode of drying pears which was developed.

  13. Time-Series Comparison of Auto/Motorcycle Ownership and Joint Mode and Destination Choice Models Based on Two Large-Scale Surveys in Jakarta

    National Research Council Canada - National Science Library

    YAGI, Sadayuki; NOBEL, Deo; KAWAGUCHI, Hirohisa

    2014-01-01

    This paper presents the results of household auto/motorcycle ownership and joint mode and destination choice models that were developed based on two large-scale travel surveys conducted eight years apart...

  14. Modelling mode choice in short trips - shifting from car to bicycle

    DEFF Research Database (Denmark)

    Halldórsdóttir, Katrín; Christensen, Linda; Jensen, Thomas Christian

    2011-01-01

    -economic variables of a representative sample of the population. The investigated sample includes 11,072 observations. The model considers five alternatives (i.e., car driver, car passenger, public transport, walk and obviously bike), for which level of service variables are calculated through assignment procedures...... relevance of the cost for short trips. Expectedly, the selection of bicycle as mode for short trips is positively related to owning a bicycle and negatively linked to owning one or more cars. Urban density has also positive correlation with the selection of sustainable transport modes....

  15. Combining RP and SP data while accounting for large choice sets and travel mode

    DEFF Research Database (Denmark)

    Abildtrup, Jens; Olsen, Søren Bøye; Stenger, Anne

    2015-01-01

    This paper analyses the use of forests for recreational purposes in Lorraine, France, a region with many forests and easy access for recreational users. This implies that residents in Lorraine can choose between a large set of forests if they decide to visit a forest. The abundance of forests...... set used for site selection modelling when the actual choice set considered is potentially large and unknown to the analyst. Easy access to forests also implies that around half of the visitors walk or bike to the forest. We apply an error-component mixed-logit model to simultaneously model the travel...... in Lorraine makes identification of the visited forests difficult. To facilitate identification of forests actually visited, we have incorporated an interactive map in a Web-based survey intended to include both revealed and stated preference data. We compare different sampling schemes to define the choice...

  16. Modelling Public Transport Route Choice with Multiple Access and Egress Modes

    NARCIS (Netherlands)

    Brands, T.; De Romph, E.; Veitch, T.; Cook, J.

    2013-01-01

    The current traffic system faces well known problems like congestion, environmental impact and use of public space. Public transport (PT) is an important mode to alleviate these problems. To be able to assess the effects of policy measures properly, it is important to model the behaviour of the

  17. Modelling public transport route choice with multiple access and egress modes

    NARCIS (Netherlands)

    Brands, Ties; de Romph, E.; Veitch, T.; Cook, J.

    2013-01-01

    The current traffic system faces well known problems like congestion, environmental impact and use of public space. Public transport (PT) is an important mode to alleviate these problems. To be able to assess the effects of policy measures properly, it is important to model the behaviour of the

  18. The Changing Importance of Factors Influencing Students' Choice of Study Mode

    Science.gov (United States)

    Bailey, Matthew; Ifenthaler, Dirk; Gosper, Maree; Kretzschmar, Mandy; Ware, Cheryl

    2015-01-01

    Despite the expansion of online and blended learning, as well as open education, until relatively recently little research has been undertaken on what motivates students to enrol in particular study modes at university level. This project contributes to recent scholarship in the field by exploring the reasons why humanities students choose to…

  19. Job search and commuting time

    NARCIS (Netherlands)

    Gorter, C.; Berg, van den G.J.

    1996-01-01

    We structurally analyze a job search model for unemployed individuals that allows jobs to have different wage/commuting-time combinations. Thestructural parameter of interest is the willingness to pay for commuting time. We use a unique dataset containing subjective responses on the optimalsearch

  20. Challenges in Computational Commutative Algebra

    OpenAIRE

    Abbott, John

    2006-01-01

    In this paper we consider a number of challenges from the point of view of the CoCoA project one of whose tasks is to develop software specialized for computations in commutative algebra. Some of the challenges extend considerably beyond the boundary of commutative algebra, and are addressed to the computer algebra community as a whole.

  1. A dynamic model of commutes

    NARCIS (Netherlands)

    Rouwendal, J.; van der Vlist, A.J.

    2005-01-01

    This paper studies the interaction between commuting, job mobility, and housing mobility. Manny conventional models assume that the employment location has priority over the residential location and that the latter is adapted to the former. This implies that commutes which start with a job change

  2. A dynamic model of commutes

    NARCIS (Netherlands)

    Rouwendal, J.; Vlist, van der A.J.

    2005-01-01

    This paper studies the interaction between commuting, job mobility, and housing mobility. Many conventional models assume that the employment location has priority over the residential location and that the latter is adapted to the former. This implies that commutes which start with a job change

  3. Preferred modes of travel among older adults: what factors affect the choice to walk instead of drive?

    Science.gov (United States)

    Naumann, Rebecca B; Dellinger, Ann M; Anderson, Melissa L; Bonomi, Amy E; Rivara, Frederick P; Thompson, Robert S

    2009-10-01

    There are many factors that influence older adults' travel choices. This paper explores the associations between mode of travel choice for a short trip and older adults' personal characteristics. This study included 406 drivers over the age of 64 who were enrolled in a large integrated health plan in the United States between 1991 and 2001. Bivariate analyses and generalized linear modeling were used to examine associations between choosing to walk or drive and respondents' self-reported general health, physical and functional abilities, and confidence in walking and driving. Having more confidence in their ability to walk versus drive increased an older adult's likelihood of walking to make a short trip by about 20% (PR=1.22; 95% CI: 1.06-1.40), and walking for exercise increased the likelihood by about 50% (PR=1.53; 95% CI=1.22-1.91). Reporting fair or poor health decreased the likelihood of walking, as did cutting down on the amount of driving due to a physical problem. Factors affecting a person's decision to walk for exercise may not be the same as those that influence their decision to walk as a mode of travel. It is important to understand the barriers to walking for exercise and walking for travel to develop strategies to help older adults meet both their exercise and mobility needs. Increasing walking over driving among older adults may require programs that increase confidence in walking and encourage walking for exercise.

  4. Impact of Survey Administration Mode on the Results of a Health-Related Discrete Choice Experiment: Online and Paper Comparison.

    Science.gov (United States)

    Determann, Domino; Lambooij, Mattijs S; Steyerberg, Ewout W; de Bekker-Grob, Esther W; de Wit, G Ardine

    Electronic data collection is increasingly being used for discrete choice experiments (DCEs). To study whether paper or electronic administration results in measurement effects. Respondents were drawn from the same sample frame (an Internet panel) and completed a nearly identical DCE survey either online or on paper during the same period. A DCE on preferences for basic health insurance served as a case study. We used panel mixed logit models for the analysis. In total, 898 respondents completed the survey: 533 respondents completed the survey online, whereas 365 respondents returned the paper survey. There were no significant differences with respect to sociodemographic characteristics between the respondents in both samples. The median response time was shorter for the online sample than for the paper sample, and a smaller proportion of respondents from the online sample were satisfied with the number of choice sets. Although some willingness- to-pay estimates were higher for the online sample, the elicited preferences for basic health insurance characteristics were similar between both modes of administration. We find no indication that online surveys yield inferior results compared with paper-based surveys, whereas the price per respondent is lower for online surveys. Researchers might want to include fewer choice sets per respondent when collecting DCE data online. Because our findings are based on a nonrandomized DCE that covers one health domain only, research in other domains is needed to support our findings. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  5. FET commutated current-FED inverter

    Science.gov (United States)

    Rippel, Wally E. (Inventor); Edwards, Dean B. (Inventor)

    1983-01-01

    A shunt switch comprised of a field-effect transistor (Q.sub.1) is employed to commutate a current-fed inverter (10) using thyristors (SCR1, SCR2) or bijunction transistors (Q.sub.2, Q.sub.3) in a full bridge (1, 2, 3, 4) or half bridge (5, 6) and transformer (T.sub.1) configuration. In the case of thyristors, a tapped inverter (12) is employed to couple the inverter to a dc source to back bias the thyristors during commutation. Alternatively, a commutation power supply (20) may be employed for that purpse. Diodes (D.sub.1, D.sub.2) in series with some voltage dropping element (resistor R.sub.12 or resistors R.sub.1, R.sub.2 or Zener diodes D.sub.4, D.sub.5) are connected in parallel with the thyristors in the half bridge and transformer configuration to assure sharing the back bias voltage. A clamp circuit comprised of a winding (18) negatively coupled to the inductor and a diode (D.sub.3) return stored energy from the inductor to the power supply for efficient operation with buck or boost mode.

  6. Active Commuting: Workplace Health Promotion for Improved Employee Well-Being and Organizational Behavior.

    Science.gov (United States)

    Page, Nadine C; Nilsson, Viktor O

    2016-01-01

    Objective: This paper describes a behavior change intervention that encourages active commuting using electrically assisted bikes (e-bikes) for health promotion in the workplace. This paper presents the preliminary findings of the intervention's impact on improving employee well-being and organizational behavior, as an indicator of potential business success. Method: Employees of a UK-based organization participated in a workplace travel behavior change intervention and used e-bikes as an active commuting mode; this was a change to their usual passive commuting behavior. The purpose of the intervention was to develop employee well-being and organizational behavior for improved business success. We explored the personal benefits and organizational co-benefits of active commuting and compared these to a travel-as-usual group of employees who did not change their behavior and continued taking non-active commutes. Results: Employees who changed their behavior to active commuting reported more positive affect, better physical health and more productive organizational behavior outcomes compared with passive commuters. In addition, there was an interactive effect of commuting mode and commuting distance: a more frequent active commute was positively associated with more productive organizational behavior and stronger overall positive employee well-being whereas a longer passive commute was associated with poorer well-being, although there was no impact on organizational behavior. Conclusion: This research provides emerging evidence of the value of an innovative workplace health promotion initiative focused on active commuting in protecting and improving employee well-being and organizational behavior for stronger business performance. It considers the significant opportunities for organizations pursuing improved workforce well-being, both in terms of employee health, and for improved organizational behavior and business success.

  7. Longitudinal associations between built environment characteristics and changes in active commuting

    Directory of Open Access Journals (Sweden)

    Lin Yang

    2017-05-01

    Full Text Available Abstract Background Few studies have assessed the predictors of changes in commuting. This study investigated the associations between physical environmental characteristics and changes in active commuting. Methods Adults from the population-based European Prospective Investigation into Cancer (EPIC-Norfolk cohort self-reported commuting patterns in 2000 and 2007. Active commuters were defined as those who reported ‘always’ or ‘usually’ walking or cycling to work. Environmental attributes around the home and route were assessed using Geographical Information Systems. Associations between potential environmental predictors and uptake and maintenance of active commuting were modelled using logistic regression, adjusting for age, sex and BMI. Results Of the 2757 participants (62% female, median baseline age: 52, IQR: 50–56 years, most were passive commuters at baseline (76%, n = 2099 and did not change their usual commute mode over 7 years (82%, n = 2277. In multivariable regression models, participants living further from work were less likely to take up active commuting and those living in neighbourhoods with more streetlights were more likely to take up active commuting (both p < 0.05. Findings for maintenance were similar: participants living further from work (over 10 km, OR: 0.06; 95% CI: 0.25 to 0.13 and had a main or secondary road on route were more likely to maintain their active commuting (OR: 0.52; 95% CI: 0.28 to 0.98. Those living in neighbourhoods with greater density of employment locations were less likely to maintain their active commuting. Conclusions Co-locating residential and employment centres as well as redesigning urban areas to improve safety for pedestrians and cyclists may encourage active commuting. Future evaluative studies should seek to assess the effects of redesigning the built environment on active commuting and physical activity.

  8. Active Commuting Behaviors in a Nordic Metropolitan Setting in Relation to Modality, Gender, and Health Recommendations

    Directory of Open Access Journals (Sweden)

    Erik Stigell

    2015-12-01

    Full Text Available Active commuting between home and place of work or study is often cited as an interesting source of physical activity in a public health perspective. However, knowledge about these behaviors is meager. This was therefore studied in adult active commuters (n = 1872 in Greater Stockholm, Sweden, a Nordic metropolitan setting. They received questionnaires and individually adjusted maps to draw their normal commuting route. Three different modality groups were identified in men and women: single-mode cyclists and pedestrians (those who only cycle or walk, respectively and dual-mode commuters (those who alternately walk or cycle. Some gender differences were observed in trip distances, frequencies, and velocities. A large majority of the commuting trip durations met the minimum health recommendation of at least 10-minute-long activity bouts. The median single-mode pedestrians and dual-mode commuters met or were close to the recommended weekly physical activity levels of at least 150 minutes most of the year, whereas the single-mode cyclists did so only during spring–mid-fall. A high total number of trips per year (range of medians: 230–390 adds to the value in a health perspective. To fully grasp active commuting behaviors in future studies, both walking and cycling should be assessed over different seasons and ideally over the whole year.

  9. Towards a differentiated understanding of active travel behaviour: using social theory to explore everyday commuting.

    Science.gov (United States)

    Guell, C; Panter, J; Jones, N R; Ogilvie, D

    2012-07-01

    Fostering physical activity is an established public health priority for the primary prevention of a variety of chronic diseases. One promising population approach is to seek to embed physical activity in everyday lives by promoting walking and cycling to and from work ('active commuting') as an alternative to driving. Predominantly quantitative epidemiological studies have investigated travel behaviours, their determinants and how they may be changed towards more active choices. This study aimed to depart from narrow behavioural approaches to travel and investigate the social context of commuting with qualitative social research methods. Within a social practice theory framework, we explored how people describe their commuting experiences and make commuting decisions, and how travel behaviour is embedded in and shaped by commuters' complex social worlds. Forty-nine semi-structured interviews and eighteen photo-elicitation interviews with accompanying field notes were conducted with a subset of the Commuting and Health in Cambridge study cohort, based in the UK. The findings are discussed in terms of three particularly pertinent facets of the commuting experience. Firstly, choice and decisions are shaped by the constantly changing and fluid nature of commuters' social worlds. Secondly, participants express ambiguities in relation to their reasoning, ambitions and identities as commuters. Finally, commuting needs to be understood as an embodied and emotional practice. With this in mind, we suggest that everyday decision-making in commuting requires the tactical negotiation of these complexities. This study can help to explain the limitations of more quantitative and static models and frameworks in predicting travel behaviour and identify future research directions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Market Entry Mode Choice: Theory and Practice. Comparing China and Brazil Cases

    Directory of Open Access Journals (Sweden)

    K. I. Zaharieva

    2016-01-01

    Full Text Available The purpose of this article is to give a brief introduction into a work, which investigated the differences between the actual strategic approach, that a company executes when entering a new market, with the approach offered by various theories. Due to confidentiality agreement signed with the company the author is not authorized to disclose any sensitive or internal information that can reveal the company’s identity. The paper combines the most common theories and approaches for market entry mode selection in order to develop a theory-based framework, which furthermore is compared to the firm’s working theory. The analysis is performed with the use of two markets, where the company already operates. This method of analysis identifies the crossing points as well as the controversial aspects of both frameworks. This way the study tests how effective and applicable are traditional theories to such a niche market that the company operates in. On the other hand by comparing the company’s entry mode selection model with the theorybased model the study identifies the imperfections of the company’s theory and makes a series of recommendations for its improvement. Additionally, it reveals the importance of combining and adjusting the theories to the specific company and not vice versa.

  11. Mode Choice between Private and Public Transport in Klang Valley, Malaysia

    Science.gov (United States)

    Karim, Mohamed Rehan; Yusoff, Sumiani

    2014-01-01

    In 2010, Klang Valley has only 17% trips each day were completed using public transport, with the rest of the 83% trips were made through private transport. The inclination towards private car usage will only get worse if the transport policy continues to be inefficient and ineffective. Under the National Key Economic Area, the priority aimed to stimulate the increase of modal share of public transport in the Klang Valley to 50% by 2020. In the 10th Malaysia Plan, the Klang Valley Mass Rapid Transit was proposed, equipped with 141 km of MRT system, and will integrate with the existing rail networks. Nevertheless, adding kilometers into the rail system will not help, if people do not make the shift from private into public transport. This research would like to assess the possible mode shift of travellers in the Klang Valley towards using public transport, based on the utility function of available transport modes. It intends to identify the criteria that will trigger their willingness to make changes in favour of public transport as targeted by the NKEA. PMID:24701165

  12. Mode choice between private and public transport in Klang Valley, Malaysia.

    Science.gov (United States)

    Chiu Chuen, Onn; Karim, Mohamed Rehan; Yusoff, Sumiani

    2014-01-01

    In 2010, Klang Valley has only 17% trips each day were completed using public transport, with the rest of the 83% trips were made through private transport. The inclination towards private car usage will only get worse if the transport policy continues to be inefficient and ineffective. Under the National Key Economic Area, the priority aimed to stimulate the increase of modal share of public transport in the Klang Valley to 50% by 2020. In the 10th Malaysia Plan, the Klang Valley Mass Rapid Transit was proposed, equipped with 141 km of MRT system, and will integrate with the existing rail networks. Nevertheless, adding kilometers into the rail system will not help, if people do not make the shift from private into public transport. This research would like to assess the possible mode shift of travellers in the Klang Valley towards using public transport, based on the utility function of available transport modes. It intends to identify the criteria that will trigger their willingness to make changes in favour of public transport as targeted by the NKEA.

  13. Quantifying commuter exposures to volatile organic compounds

    Science.gov (United States)

    Kayne, Ashleigh

    environments where there could be multiple chemicals present that may produce a PID signal (such as nitrogen dioxide), Tenax TA samplers may be a better choice for measuring BTEX. Tenax TA measurements were the only suitable method within this study to measure commuter's BTEX exposure in Fort Collins, Colorado.

  14. A multipurpose switched reluctance motor with a series commutation buffer

    Directory of Open Access Journals (Sweden)

    L.A. Vasil'ev

    2014-06-01

    Full Text Available In this paper, a power-supply circuit for a multipurpose switched reluctance motor with a series commutation buffer is presented. It is shown that a series buffer improves output characteristics of multipurpose switched reluctance motors under supply from a single-phase circuit and also lifts necessity of switching capacitors according to the motor power supply modes.

  15. -commuting maps and invariant approximations

    Directory of Open Access Journals (Sweden)

    Rhoades BE

    2006-01-01

    Full Text Available We obtain common fixed point results for generalized -nonexpansive -commuting maps. As applications, various best approximation results for this class of maps are derived in the setup of certain metrizable topological vector spaces.

  16. Computational linear and commutative algebra

    CERN Document Server

    Kreuzer, Martin

    2016-01-01

    This book combines, in a novel and general way, an extensive development of the theory of families of commuting matrices with applications to zero-dimensional commutative rings, primary decompositions and polynomial system solving. It integrates the Linear Algebra of the Third Millennium, developed exclusively here, with classical algorithmic and algebraic techniques. Even the experienced reader will be pleasantly surprised to discover new and unexpected aspects in a variety of subjects including eigenvalues and eigenspaces of linear maps, joint eigenspaces of commuting families of endomorphisms, multiplication maps of zero-dimensional affine algebras, computation of primary decompositions and maximal ideals, and solution of polynomial systems. This book completes a trilogy initiated by the uncharacteristically witty books Computational Commutative Algebra 1 and 2 by the same authors. The material treated here is not available in book form, and much of it is not available at all. The authors continue to prese...

  17. Commuting Π-regular rings

    Directory of Open Access Journals (Sweden)

    Shervin Sahebi

    2014-05-01

    Full Text Available ‎$R$ is called commuting regular ring (resp‎. ‎semigroupif‎ for each $x,y\\in R$ there exists $a\\in R$‎ such that$xy=yxayx$‎. ‎In this paper‎, ‎we introduce the concept of‎‎commuting $\\pi$-regular rings (resp‎. ‎semigroups and‎‎study various properties of them.

  18. Medical students’ personal choice for mode of delivery in Santa Catarina, Brazil: a cross-sectional, quantitative study

    Directory of Open Access Journals (Sweden)

    Watanabe Tatiane

    2012-07-01

    Full Text Available Abstract Background The increase in overall rates of cesarean sections (CS in Brazil causes concern and it appears that multiple factors are involved in this fact. In 2009, undergraduate students in the first and final years of medical school at the University of Santa Catarina answered questionnaires regarding their choice of mode of delivery. The aim of the study was to evaluate whether the education process affects decision-making regarding the waay of childbirth preferred by medical students. Methods A cross-sectional, quantitative study was conducted based on data obtained from questionnaires applied to medical students. The questions addressed four different scenarios in childbirth, as follows: under an uneventful pregnancy; the mode of delivery for a pregnant woman under their care; the best choice as a healthcare manager and lastly, choosing the birth of their own child. For each circumstance, there was an open question to explain their choice. Results A total of 189 students answered the questionnaires. For any uneventful pregnancy and for a pregnant woman under their care, 8.46% of the students would opt for CS. As a healthcare manager, only 2.64% of the students would recommend CS. For these three scenarios, the answers of the students in the first year did not differ from those given by students in the sixth year. In the case of the student’s own or a partner’s pregnancy, 41.4% of those in the sixth year and 16.8% of those in the first year would choose a CS. A positive association was found between being a sixth year student and a personal preference for CS according to logistic regression (OR = 2.91; 95%CI: 1.03–8.30. Pain associated with vaginal delivery was usually the reason for choosing a CS. Conclusions A higher number of sixth year students preferred a CS for their own pregnancy (or their partner’s compared to first year students. Pain associated with vaginal delivery was the most common reason given for haven chosen

  19. Medical students' personal choice for mode of delivery in Santa Catarina, Brazil: a cross-sectional, quantitative study.

    Science.gov (United States)

    Watanabe, Tatiane; Knobel, Roxana; Suchard, Guilherme; Franco, Mario Julio; d'Orsi, Eleonora; Consonni, Elenice Bertanha; Consonni, Marcos

    2012-07-20

    The increase in overall rates of cesarean sections (CS) in Brazil causes concern and it appears that multiple factors are involved in this fact. In 2009, undergraduate students in the first and final years of medical school at the University of Santa Catarina answered questionnaires regarding their choice of mode of delivery. The aim of the study was to evaluate whether the education process affects decision-making regarding the way of childbirth preferred by medical students. A cross-sectional, quantitative study was conducted based on data obtained from questionnaires applied to medical students. The questions addressed four different scenarios in childbirth, as follows: under an uneventful pregnancy; the mode of delivery for a pregnant woman under their care; the best choice as a healthcare manager and lastly, choosing the birth of their own child. For each circumstance, there was an open question to explain their choice. A total of 189 students answered the questionnaires. For any uneventful pregnancy and for a pregnant woman under their care, 8.46% of the students would opt for CS. As a healthcare manager, only 2.64% of the students would recommend CS. For these three scenarios, the answers of the students in the first year did not differ from those given by students in the sixth year. In the case of the student's own or a partner's pregnancy, 41.4% of those in the sixth year and 16.8% of those in the first year would choose a CS. A positive association was found between being a sixth year student and a personal preference for CS according to logistic regression (OR = 2.91; 95%CI: 1.03-8.30). Pain associated with vaginal delivery was usually the reason for choosing a CS. A higher number of sixth year students preferred a CS for their own pregnancy (or their partner's) compared to first year students. Pain associated with vaginal delivery was the most common reason given for haven chosen a CS. The students' preference for childbirth changed over time during

  20. Transfer of learning in choice reactions: The roles of stimulus type, response mode, and set-level compatibility.

    Science.gov (United States)

    Yamaguchi, Motonori; Chen, Jing; Proctor, Robert W

    2015-08-01

    The Simon effect refers to the advantage of responding to spatially compatible stimuli. This effect can be eliminated or even reversed to favor spatially incompatible stimuli after participants practice a choice-reaction task with spatially incompatible mappings (e.g., pressing left and right keys to stimuli on the right and left, respectively). This transfer of incompatible spatial associations has been observed under conditions in which responses were made manually (e.g., keypresses, moving a joystick). The present study used vocal responses to reveal the primary determinants of the transfer effect, dissociating the influences of stimulus type, response mode, and their interaction (set-level compatibility). The results suggest that contextual match between the practice and transfer tasks with respect to stimulus type and response mode determined transfer of incompatible associations to the Simon task, and stimulus type determined the efficiency of acquiring new associations. However, there was little evidence that set-level compatibility plays any major role in either acquisition or transfer of spatial associations.

  1. Commuting projections on graphs

    Energy Technology Data Exchange (ETDEWEB)

    Vassilevski, Panayot S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Center for Applied Scientific Computing; Zikatanov, Ludmil T. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Mathematics

    2013-02-19

    For a given (connected) graph, we consider vector spaces of (discrete) functions defined on its vertices and its edges. These two spaces are related by a discrete gradient operator, Grad and its adjoint, ₋Div, referred to as (negative) discrete divergence. We also consider a coarse graph obtained by aggregation of vertices of the original one. Then a coarse vertex space is identified with the subspace of piecewise constant functions over the aggregates. We consider the ℓ2-projection QH onto the space of these piecewise constants. In the present paper, our main result is the construction of a projection π H from the original edge-space onto a properly constructed coarse edge-space associated with the edges of the coarse graph. The projections π H and QH commute with the discrete divergence operator, i.e., we have div π H = QH div. The respective pair of coarse edge-space and coarse vertexspace offer the potential to construct two-level, and by recursion, multilevel methods for the mixed formulation of the graph Laplacian which utilizes the discrete divergence operator. The performance of one two-level method with overlapping Schwarz smoothing and correction based on the constructed coarse spaces for solving such mixed graph Laplacian systems is illustrated on a number of graph examples.

  2. The Comparison of Mode Choice Sensitivity to the Reduction of Travel Time and Cost in Multimodal Trip

    OpenAIRE

    Mohammad Ganji; Hamed Eftekhar; Foad Shokri; Amiruddin Ismail; O.K. Riza Atiq

    2013-01-01

    Nowadays, with the extension of travel distances and accessibility to the various commuting options, multimodal trip proposes as the most competent travelling strategy. However, with increasing in demand by using these options as well as metro, subway, buses, cycles and sidewalk, some problems arose. The import of this quantitative study is to sympathize with the significance of the multimodal as a novel factor in the transportation. In this study, we discussed about cost and time as two sign...

  3. Fitness, Fatness and Active School Commuting among Liverpool Schoolchildren.

    Science.gov (United States)

    Noonan, Robert J; Boddy, Lynne M; Knowles, Zoe R; Fairclough, Stuart J

    2017-08-31

    This study investigated differences in health outcomes between active and passive school commuters, and examined associations between parent perceptions of the neighborhood environment and active school commuting (ASC). One hundred-ninety-four children (107 girls), aged 9-10 years from ten primary schools in Liverpool, England, participated in this cross-sectional study. Measures of stature, body mass, waist circumference and cardiorespiratory fitness (CRF) were taken. School commute mode (active/passive) was self-reported and parents completed the neighborhood environment walkability scale for youth. Fifty-three percent of children commuted to school actively. Schoolchildren who lived in more deprived neighborhoods perceived by parents as being highly connected, unaesthetic and having mixed land-use were more likely to commute to school actively (p < 0.05). These children were at greatest risk of being obese and aerobically unfit(p < 0.01). Our results suggest that deprivation may explain the counterintuitive relationship between obesity, CRF and ASC in Liverpool schoolchildren. These findings encourage researchers and policy makers to be equally mindful of the social determinants of health when advocating behavioral and environmental health interventions. Further research exploring contextual factors to ASC, and examining the concurrent effect of ASC and diet on weight status by deprivation is needed.

  4. Fitness, Fatness and Active School Commuting among Liverpool Schoolchildren

    Directory of Open Access Journals (Sweden)

    Robert J. Noonan

    2017-08-01

    Full Text Available This study investigated differences in health outcomes between active and passive school commuters, and examined associations between parent perceptions of the neighborhood environment and active school commuting (ASC. One hundred-ninety-four children (107 girls, aged 9–10 years from ten primary schools in Liverpool, England, participated in this cross-sectional study. Measures of stature, body mass, waist circumference and cardiorespiratory fitness (CRF were taken. School commute mode (active/passive was self-reported and parents completed the neighborhood environment walkability scale for youth. Fifty-three percent of children commuted to school actively. Schoolchildren who lived in more deprived neighborhoods perceived by parents as being highly connected, unaesthetic and having mixed land-use were more likely to commute to school actively (p < 0.05. These children were at greatest risk of being obese and aerobically unfit(p < 0.01. Our results suggest that deprivation may explain the counterintuitive relationship between obesity, CRF and ASC in Liverpool schoolchildren. These findings encourage researchers and policy makers to be equally mindful of the social determinants of health when advocating behavioral and environmental health interventions. Further research exploring contextual factors to ASC, and examining the concurrent effect of ASC and diet on weight status by deprivation is needed.

  5. Towards a differentiated understanding of active travel behaviour: Using social theory to explore everyday commuting

    Science.gov (United States)

    Guell, C.; Panter, J.; Jones, N.R.; Ogilvie, D.

    2012-01-01

    Fostering physical activity is an established public health priority for the primary prevention of a variety of chronic diseases. One promising population approach is to seek to embed physical activity in everyday lives by promoting walking and cycling to and from work (‘active commuting’) as an alternative to driving. Predominantly quantitative epidemiological studies have investigated travel behaviours, their determinants and how they may be changed towards more active choices. This study aimed to depart from narrow behavioural approaches to travel and investigate the social context of commuting with qualitative social research methods. Within a social practice theory framework, we explored how people describe their commuting experiences and make commuting decisions, and how travel behaviour is embedded in and shaped by commuters' complex social worlds. Forty-nine semi-structured interviews and eighteen photo-elicitation interviews with accompanying field notes were conducted with a subset of the Commuting and Health in Cambridge study cohort, based in the UK. The findings are discussed in terms of three particularly pertinent facets of the commuting experience. Firstly, choice and decisions are shaped by the constantly changing and fluid nature of commuters' social worlds. Secondly, participants express ambiguities in relation to their reasoning, ambitions and identities as commuters. Finally, commuting needs to be understood as an embodied and emotional practice. With this in mind, we suggest that everyday decision-making in commuting requires the tactical negotiation of these complexities. This study can help to explain the limitations of more quantitative and static models and frameworks in predicting travel behaviour and identify future research directions. PMID:22486840

  6. The Relationships between Urban Form and Urban Commuting: An Empirical Study in China

    Directory of Open Access Journals (Sweden)

    Yu Song

    2017-07-01

    Full Text Available Urban sustainable development strategies are of great importance to rapidly urbanized countries such as China. One of the most challenging problems is how to coordinate urban spatial development with social efficiency and environmental protection, e.g., highly efficient low-carbon urban traffic. Despite broad research efforts with respect to the influence of urban form on travel patterns, questions persist as to the impact of compact urban form on travel distance and modes. In this study, we adopted urban form metrics to capture key dimensions of urban form with the aid of image processing and spatial analysis based on satellite images and statistical data from the cases of 35 cities. Combined with urban travel survey data, we empirically examined the relationships between urban form and travel patterns of local urban residents. The results showed that urban form and travel patterns have regionalized characteristics, e.g., the eastern cities are characterized by disperse urban development patterns and longer commuting times on average compared with western and central cities. We found that relatively smaller built-up areas, higher degrees of urban spatial agglomeration and more paved road area per person would decrease the commuting time of urban residents. We also found that the public transport choices of urban residents are positively associated with built-up areas and commuting times, which suggests the need for provision and promotion of facilities for a high-quality public transport system. The findings provide helpful suggestions for the planning of sustainable urban form and development of transportation.

  7. Local environment and social factors in primary school children's afterschool commute in China

    Directory of Open Access Journals (Sweden)

    John Zacharias

    2017-09-01

    Full Text Available The rapid decline in young children's active commutes to and from school has prompted investigations into ways to raise activity levels. The period after school is recognized as very important in the daily activity regime of primary school children. In this study, we examine the relative effects of local environmental factors and socio-economic status on children's after-school commute mode choice. Environmental factors are pedestrian priority streets, street intersection density, motorways, shops, and play spaces. Property values are used as a proxy for income. Twenty-four school districts are selected using intersection density and motorway length as criteria. All children's exit behaviors were film-recorded on October weekdays and extracted as four choices–alone, in a group of children, on foot with a parent or guardian, on e-bike driven by an adult. A multinomial logistic regression reveals that gated communities, higher priced housing, motorways and bus stops are associated with children accompanied by adults. The presence of pedestrian streets is associated with children travelling alone and in groups. Greater travel distance is also associated with parents accompanying children on foot or on e-bike. The amount of play space is associated with children leaving school in groups. Overall, social and environmental factors are influential in the independent travel of primary school children after the school day ends in south China.

  8. Urban air quality comparison for bus, tram, subway and pedestrian commutes in Barcelona.

    Science.gov (United States)

    Moreno, Teresa; Reche, Cristina; Rivas, Ioar; Cruz Minguillón, Maria; Martins, Vânia; Vargas, Concepción; Buonanno, Giorgio; Parga, Jesus; Pandolfi, Marco; Brines, Mariola; Ealo, Marina; Sofia Fonseca, Ana; Amato, Fulvio; Sosa, Garay; Capdevila, Marta; de Miguel, Eladio; Querol, Xavier; Gibbons, Wes

    2015-10-01

    Access to detailed comparisons in air quality variations encountered when commuting through a city offers the urban traveller more informed choice on how to minimise personal exposure to inhalable pollutants. In this study we report on an experiment designed to compare atmospheric contaminants inhaled during bus, subway train, tram and walking journeys through the city of Barcelona. Average number concentrations of particles 10-300 nm in size, N, are lowest in the commute using subway trains (N5.0×10(4) cm(-3)), with extreme transient peaks at busy traffic crossings commonly exceeding 1.0×10(5) cm(-3) and accompanied by peaks in Black Carbon and CO. Subway particles are coarser (mode 90 nm) than in buses, trams or outdoors (1200 ppm in crowded buses and trains. There are also striking differences in inhalable particle chemistry depending on the route chosen, ranging from aluminosiliceous at roadsides and near pavement works, ferruginous with enhanced Mn, Co, Zn, Sr and Ba in the subway environment, and higher levels of Sb and Cu inside the bus. We graphically display such chemical variations using a ternary diagram to emphasise how "air quality" in the city involves a consideration of both physical and chemical parameters, and is not simply a question of measuring particle number or mass. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Potential to increase active commuting level in university area (Case study: Universitas Gadjah Mada)

    Science.gov (United States)

    Devi, M. K.

    2017-06-01

    In order to alleviate the negative impacts of motorized vehicle use as well as create sustainable environment within campus area, it is pivotal to encourage mode shifting among university students. Active transport modes such as walking, cycling, and using public transport can be considered as alternative modes. This paper tried to identify the potential to increase active commuting in UGM by understanding student’s travel behavior. ANOVA test was employed to identify the perceptions between students across residential zones toward motivators and barriers to actively commute. The findings were used to propose strategies for increasing active commuting level in UGM, which are: reducing barriers to actively commute, improving public transport services, improving walking and cycling facilities, and introducing programs to discourage motorized vehicle use.

  10. The effects of commuter pedestrian traffic on the use of stairs in an urban setting.

    Science.gov (United States)

    Andersen, Ross E; Bauman, Adrian E

    2011-01-01

    Most public health physical activity guidelines now encourage people to look for opportunities to accumulate physical activity throughout the day. Climbing stairs in lieu of riding escalators is a prime opportunity to make healthier choices that promote active living. The purpose of this investigation was to examine the effects of pedestrian commuter traffic on choices to ride an escalator, walk up an escalator, or walk up adjacent stairs in a busy urban subway station at rush hour. A total of 9766 commuters were observed by two recorders for a 2.5-hour period during the morning rush hour over 8 weeks as to whether the commuters walked up stairs or rode an adjacent escalator in a subway station. The number of observations per 5-minute block was recorded, and an index of commuter traffic was computed. Demographic information and use of escalators/stairs were also recorded. An urban subway station with a two-flight staircase adjacent to an escalator. Adult commuters travelling to work during the morning rush hour. Physical activity choices were examined in relation to commuter traffic. Demographic information, such as age, race, and weight status, were also considered. A χ(2) analysis was used to examine differences in proportions across variables of interest. Means were compared by using multivariate analysis of variance, and confidence intervals were computed. During the least-heavy commuter traffic period, only 11.2% of commuters chose to walk up the stairs, whereas significantly more did so during moderate 18.7% and high 20.8% commuter traffic periods (χ(2)  =  61.8, p < .001). During low-traffic times, significantly more commuters (21.4%) walked up the escalators compared with moderate-traffic (18.0%) or high-traffic (18.3%) periods. African-American commuters passively rode the escalator more (68.2%) than white commuters (56.7%), and their patterns were less affected by commuter traffic (p < .05). Congestion in public places can have a significant effect

  11. Revealing the Value of “Green” and the Small Group with a Big Heart in Transportation Mode Choice

    Directory of Open Access Journals (Sweden)

    David Gaker

    2013-07-01

    Full Text Available To address issues of climate change, people are more and more being presented with the greenhouse gas emissions associated with their alternatives. Statements of pounds or kilograms of CO2 are showing up in trip planners, car advertisements, and even restaurant menus under the assumption that this information influences behavior. This research contributes to the literature that investigates how travelers respond to such information. Our objective is to better understand the “value of green” or how much travelers are willing to pay in money in order to reduce the CO2 associated with their travel. As with previous work, we designed and conducted a mode choice experiment using methods that have long been used to study value of time. The contributions of this paper are twofold. First, we employ revealed preference data, whereas previous studies have been based on stated preferences. Second, we provide new insight on how the value of green is distributed in the population. Whereas previous work has specified heterogeneity either systematically or with a continuous distribution, we find that a latent class choice model specification better fits the data and also is attractive behaviorally. The best fitting latent class model has two classes: one large class (76% of the sample who are not willing to spend any time or money to reduce their CO2 and a second class (24% of the sample who value reducing their CO2 at a very high rate of $2.68 per pound of reduction—our so-called small group with a big heart. We reanalyzed three datasets that we had previously collected and found considerable robustness of this two class result.

  12. Walk Score, Transportation Mode Choice, and Walking Among French Adults: A GPS, Accelerometer, and Mobility Survey Study

    Directory of Open Access Journals (Sweden)

    Dustin T. Duncan

    2016-06-01

    Full Text Available Background: Few studies have used GPS data to analyze the relationship between Walk Score, transportation choice and walking. Additionally, the influence of Walk Score is understudied using trips rather than individuals as statistical units. The purpose of this study is to examine associations at the trip level between Walk Score, transportation mode choice, and walking among Paris adults who were tracked with GPS receivers and accelerometers in the RECORD GPS Study. Methods: In the RECORD GPS Study, 227 participants were tracked during seven days with GPS receivers and accelerometers. Participants were also surveyed with a GPS-based web mapping application on their activities and transportation modes for all trips (6969 trips. Walk Score, which calculates neighborhood walkability, was assessed for each origin and destination of every trip. Multilevel logistic and linear regression analyses were conducted to estimate associations between Walk Score and walking in the trip or accelerometry-assessed number of steps for each trip, after adjustment for individual/neighborhood characteristics. Results: The mean overall Walk Scores for trip origins were 87.1 (SD = 14.4 and for trip destinations 87.1 (SD = 14.5. In adjusted trip-level associations between Walk Score and walking only in the trip, we found that a walkable neighborhood in the trip origin and trip destination was associated with increased odds of walking in the trip assessed in the survey. The odds of only walking in the trip were 3.48 (95% CI: 2.73 to 4.44 times higher when the Walk Score for the trip origin was “Walker’s Paradise” compared to less walkable neighborhoods (Very/Car-Dependent or Somewhat Walkable, with an identical independent effect of trip destination Walk Score on walking. The number of steps per 10 min (as assessed with accelerometry was cumulatively higher for trips both originating and ending in walkable neighborhoods (i.e., “Very Walkable”. Conclusions

  13. Walk Score, Transportation Mode Choice, and Walking Among French Adults: A GPS, Accelerometer, and Mobility Survey Study.

    Science.gov (United States)

    Duncan, Dustin T; Méline, Julie; Kestens, Yan; Day, Kristen; Elbel, Brian; Trasande, Leonardo; Chaix, Basile

    2016-06-20

    Few studies have used GPS data to analyze the relationship between Walk Score, transportation choice and walking. Additionally, the influence of Walk Score is understudied using trips rather than individuals as statistical units. The purpose of this study is to examine associations at the trip level between Walk Score, transportation mode choice, and walking among Paris adults who were tracked with GPS receivers and accelerometers in the RECORD GPS Study. In the RECORD GPS Study, 227 participants were tracked during seven days with GPS receivers and accelerometers. Participants were also surveyed with a GPS-based web mapping application on their activities and transportation modes for all trips (6969 trips). Walk Score, which calculates neighborhood walkability, was assessed for each origin and destination of every trip. Multilevel logistic and linear regression analyses were conducted to estimate associations between Walk Score and walking in the trip or accelerometry-assessed number of steps for each trip, after adjustment for individual/neighborhood characteristics. The mean overall Walk Scores for trip origins were 87.1 (SD = 14.4) and for trip destinations 87.1 (SD = 14.5). In adjusted trip-level associations between Walk Score and walking only in the trip, we found that a walkable neighborhood in the trip origin and trip destination was associated with increased odds of walking in the trip assessed in the survey. The odds of only walking in the trip were 3.48 (95% CI: 2.73 to 4.44) times higher when the Walk Score for the trip origin was "Walker's Paradise" compared to less walkable neighborhoods (Very/Car-Dependent or Somewhat Walkable), with an identical independent effect of trip destination Walk Score on walking. The number of steps per 10 min (as assessed with accelerometry) was cumulatively higher for trips both originating and ending in walkable neighborhoods (i.e., "Very Walkable"). Walkable neighborhoods were associated with increases in walking

  14. Walk Score, Transportation Mode Choice, and Walking Among French Adults: A GPS, Accelerometer, and Mobility Survey Study

    Science.gov (United States)

    Duncan, Dustin T.; Méline, Julie; Kestens, Yan; Day, Kristen; Elbel, Brian; Trasande, Leonardo; Chaix, Basile

    2016-01-01

    Background: Few studies have used GPS data to analyze the relationship between Walk Score, transportation choice and walking. Additionally, the influence of Walk Score is understudied using trips rather than individuals as statistical units. The purpose of this study is to examine associations at the trip level between Walk Score, transportation mode choice, and walking among Paris adults who were tracked with GPS receivers and accelerometers in the RECORD GPS Study. Methods: In the RECORD GPS Study, 227 participants were tracked during seven days with GPS receivers and accelerometers. Participants were also surveyed with a GPS-based web mapping application on their activities and transportation modes for all trips (6969 trips). Walk Score, which calculates neighborhood walkability, was assessed for each origin and destination of every trip. Multilevel logistic and linear regression analyses were conducted to estimate associations between Walk Score and walking in the trip or accelerometry-assessed number of steps for each trip, after adjustment for individual/neighborhood characteristics. Results: The mean overall Walk Scores for trip origins were 87.1 (SD = 14.4) and for trip destinations 87.1 (SD = 14.5). In adjusted trip-level associations between Walk Score and walking only in the trip, we found that a walkable neighborhood in the trip origin and trip destination was associated with increased odds of walking in the trip assessed in the survey. The odds of only walking in the trip were 3.48 (95% CI: 2.73 to 4.44) times higher when the Walk Score for the trip origin was “Walker’s Paradise” compared to less walkable neighborhoods (Very/Car-Dependent or Somewhat Walkable), with an identical independent effect of trip destination Walk Score on walking. The number of steps per 10 min (as assessed with accelerometry) was cumulatively higher for trips both originating and ending in walkable neighborhoods (i.e., “Very Walkable”). Conclusions: Walkable

  15. Commuting in the settlement system of Serbia

    Directory of Open Access Journals (Sweden)

    Lukić Vesna

    2011-01-01

    Full Text Available Territorial organization of settlement system is the framework for internal migration flows. The purpose of this paper is to consider the relation between commuting and the settlement structure. Commuting patterns and characteristics of commuters in Serbia are relatively unknown and insufficiently researched, and as such, can not be adequately used in creation of development strategies and public policies which would include commuters' issues. It has been emphasized the importance of research of commuting ties between different settlements and also pointed out in which way commuting flows could be researched and analyzed by using existing sources, due to better understanding of connections between migrations and settlements. Commuting patterns of workers in Serbia and interrelations between the scope and the structure of commuting flows, as well as the type and population size of settlements in Serbia have been examined. Apart from territorial dimension of commuting phenomenon, socio-economic component of commuting population has also been considered. The use of costumised tabulations from 2002 Census have enabled us to examine all types of commuting and emphasise dominant directions of commuting flows of economically active population according to gender, level of education and sector of economic activity, within the settlement hierarchy. Workers have been classified into seven groups according to place of residence and place of work. The findings reveal there is a clear connection between the hierarchy structure and commuting patterns in Serbia. Further, we find some evidence that only 9,5% of workers - commuters have been working in the settlement of the same population size and type such as their residing settlement. Commuting flows within Serbia’s settlement system point out to certain variations when looking at individual categories of population, but it can be concluded that there is general trend of commuting "upwards" within the

  16. Non-Commutativity and the Theta Term

    Science.gov (United States)

    Obregón, O.; Santos-Silva, R.

    2014-11-01

    In the presente paper we will study the non-commutativity in the space-time through the map developed by N. Seiberg and E. Witten, and explore the topological implications due to the introduction of non-commutativity. We will explore this topological properties using a non-commutative extension of the θ-term (second Chern class) on the 4dimensional sphere.

  17. 8 CFR 211.5 - Alien commuters.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent residence.... An alien commuter engaged in seasonal work will be presumed to have taken up residence in the United...

  18. Associations between active commuting to school and objectively measured physical activity

    DEFF Research Database (Denmark)

    Børrestad L, Anita Bjørkelund; Ostergaard, Lars; Andersen, Lars Bo

    2013-01-01

    . Physical activity was measured with cycle computers and accelerometers for 4 days. Mode of commuting and demographic information was self-reported in a questionnaire. Results: Children who reported to cycle to school spent significantly more time cycling than those who walked to school, 53.6 (SD = ± 33......Background: To provide more accurate assessment of commuting behavior and potential health effect, it is important to have accurate methods. Therefore, the current study aimed to a) compare questionnaire reported mode of commuting with objectively measured data from accelerometer and cycle computer......, b) compare moderate vigorous physical activity (MVPA) among children cycling vs. walking to school, and c) thus calculate possible underestimated MVPA, when using accelerometers to measure commuter cycling. Methods: A total of 78 children, average age 11.4 (SD = 0.5), participated in the study...

  19. Modeling the Joint Choice Decisions on Urban Shopping Destination and Travel-to-Shop Mode: A Comparative Study of Different Structures

    Directory of Open Access Journals (Sweden)

    Chuan Ding

    2014-01-01

    Full Text Available The joint choice of shopping destination and travel-to-shop mode in downtown area is described by making use of the cross-nested logit (CNL model structure that allows for potential interalternative correlation along the both choice dimensions. Meanwhile, the traditional multinomial logit (MNL model and nested logit (NL model are also formulated, respectively. This study uses the data collected in the downtown areas of Maryland-Washington, D.C. region, for shopping trips, considering household, individual, land use, and travel related characteristics. The results of the model reveal the significant influencing factors on joint choice travel behavior between shopping destination and travel mode. A comparison of the different models shows that the proposed CNL model structure offers significant improvements in capturing unobserved correlations between alternatives over MNL model and NL model. Moreover, a Monte Carlo simulation for a group of scenarios assuming that there is an increase in parking fees in downtown area is undertaken to examine the impact of a change in car travel cost on the joint choice of shopping destination and travel mode switching. The results are expected to give a better understanding on the shopping travel behavior.

  20. On CNC commuting contractive tuples

    Indian Academy of Sciences (India)

    The characteristic function has been an important tool for studying completely non-unitary contractions on Hilbert spaces. In this note, we consider completely non-coisometric contractive tuples of commuting operators on a Hilbert space H . We show that the characteristic function, which is now an operator-valued analytic ...

  1. On commuting operator exponentials, II

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 123; Issue 1. On Commuting Operator Exponentials, II. Fotios C Paliogiannis. Volume 123 Issue 1 February 2013 pp 27-31. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/pmsc/123/01/0027-0031. Keywords.

  2. On commuting operator exponentials, II

    Indian Academy of Sciences (India)

    p. 268 of. [8]). In the present paper we are concerned with the reverse implication, when A and B are normal operators. Commuting exponentials of bounded normal operators have been studied in [4], [5] and [9]. Here, we extend these results to ...

  3. Magnitude control of commutator errors

    NARCIS (Netherlands)

    Geurts, Bernardus J.; Wesseling, P.; Oñate, E.; Périaux, J.

    2006-01-01

    Non-uniform filtering of the Navier-Stokes equations expresses itself, next to the turbulent stresses, in additional closure terms known as commutator errors. These terms require explicit subgrid modeling if the non-uniformity of the filter is sufficiently pronounced. We derive expressions for the

  4. Workers' marginal costs of commuting

    DEFF Research Database (Denmark)

    van Ommeren, Jos; Fosgerau, Mogens

    2009-01-01

    This paper applies a dynamic search model to estimate workers' marginal costs of commuting, including monetary and time costs. Using data on workers' job search activity as well as moving behaviour, for the Netherlands, we provide evidence that, on average, workers' marginal costs of one hour of ...

  5. Search Theory and Commuting Behaviour

    NARCIS (Netherlands)

    Rouwendal, J.

    2004-01-01

    This paper argues that search theory is a useful addition to the way economists and geographers have approached the study of commuting behavior. This is illustrated by showing that introduction of a spatial element into the standard model of job search leads to the prediction of critical isochrones.

  6. Exploring the impact of household interactions on car use for home-based tours. A multilevel analysis of mode choice using data from the first two waves of the Netherlands Mobility Panel

    NARCIS (Netherlands)

    Olde Kalter, Marie-José José Theresia; Geurs, Karst Teunis

    2016-01-01

    While most studies on mode choice behaviour and households are typically based on individual travel behaviour decisions, less is known about how relations inside households affect mode choice. This paper addresses this topic by examining intra- and inter-household variation in car use. The decision

  7. Criterion distances and environmental correlates of active commuting to school in children

    Directory of Open Access Journals (Sweden)

    D'Haese Sara

    2011-08-01

    Full Text Available Abstract Background Active commuting to school can contribute to daily physical activity levels in children. Insight into the determinants of active commuting is needed, to promote such behavior in children living within a feasible commuting distance from school. This study determined feasible distances for walking and cycling to school (criterion distances in 11- to 12-year-old Belgian children. For children living within these criterion distances from school, the correlation between parental perceptions of the environment, the number of motorized vehicles per family and the commuting mode (active/passive to school was investigated. Methods Parents (n = 696 were contacted through 44 randomly selected classes of the final year (sixth grade in elementary schools in East- and West-Flanders. Parental environmental perceptions were obtained using the parent version of Neighborhood Environment Walkability Scale for Youth (NEWS-Y. Information about active commuting to school was obtained using a self-reported questionnaire for parents. Distances from the children's home to school were objectively measured with Routenet online route planner. Criterion distances were set at the distance in which at least 85% of the active commuters lived. After the determination of these criterion distances, multilevel analyses were conducted to determine correlates of active commuting to school within these distances. Results Almost sixty percent (59.3% of the total sample commuted actively to school. Criterion distances were set at 1.5 kilometers for walking and 3.0 kilometers for cycling. In the range of 2.01 - 2.50 kilometers household distance from school, the number of passive commuters exceeded the number of active commuters. For children who were living less than 3.0 kilometers away from school, only perceived accessibility by the parents was positively associated with active commuting to school. Within the group of active commuters, a longer distance to school

  8. Particle exposure and inhaled dose during commuting in Singapore

    Science.gov (United States)

    Tan, Sok Huang; Roth, Matthias; Velasco, Erik

    2017-12-01

    Exposure concentration and inhaled dose of particles during door-to-door trips walking and using motorized transport modes (subway, bus, taxi) are evaluated along a selected route in a commercial district of Singapore. Concentrations of particles smaller than 2.5 μm in size (PM2.5), black carbon, particle-bound polycyclic aromatic hydrocarbons, number of particles, active surface area and carbon monoxide have been measured in-situ using portable instruments. Simultaneous measurements were conducted at a nearby park to capture the background concentrations. The heart rate of the participants was monitored during the measurements as a proxy of the inhalation rate used to calculate the inhaled dose of particles. All measured metrics were highest and well above background levels during walking. No significant difference was observed in the exposure concentration of PM2.5 for the three motorized transport modes, unlike for the metrics associated with ultrafine particles (UFP). The concentration of these freshly emitted particles was significantly lower on subway trips. The absence of combustion sources, use of air conditioning and screen doors at station platforms are effective measures to protect passengers' health. For other transport modes, sections of trips close to accelerating and idling vehicles, such as bus stops, traffic junctions and taxi stands, represent hotspots of particles. Reducing the waiting time at such locations will lower pollutants exposure and inhaled dose during a commute. After taking into account the effect of inhalation and travel duration when calculating dose, the health benefit of commuting by subway for this particular district of Singapore became even more evident. For example, pedestrians breathe in 2.6 and 3.2 times more PM2.5 and UFP, respectively than subway commuters. Public buses were the second best alternative. Walking emerged as the worst commuting mode in terms of particle exposure and inhaled dose.

  9. Associations of commuting to school and work with demographic variables and with weight status in eight European countries: The ENERGY-cross sectional study.

    Science.gov (United States)

    Te Velde, Saskia J; Haraldsen, Eli; Vik, Frøydis N; De Bourdeaudhuij, Ilse; Jan, Natasa; Kovacs, Eva; Moreno, Luis A; Dössegger, Alain; Manios, Yannis; Brug, Johannes; Bere, Elling

    2017-06-01

    This study aims to assess the prevalence of different modes of commuting to school and work for 10-12year-olds and their parents; to assess the associations with demographic variables (country, sex, parental education and ethnicity) and with weight status in eight European countries. As part of the ENERGY project a cross-sectional survey was conducted in 2010 in which modes of commuting and socio-demographic variables for children (N=7903) and one of their parents (n=6455) were measured by questionnaires. Children's weight and height were objectively measured; parents self-reported their weight and height. Logistic multilevel regression analyses assessed the associations between mode of commuting and overweight. Differences between countries and differences in mode of commuting according to demographic variables were tested using χ 2 -test and Marascuilo's Post-hoc analysis. There were marked differences between countries, especially regarding cycling to school, which was common in The Netherlands and Norway and rare in Greece and Spain. Demographic variables were associated with mode of commuting in children and parents. Mode of commuting was not associated with being overweight in children, after adjustment for demographic variables. Bicycling to work, but not other modes of commuting, was significantly inversely associated with being overweight among parents (OR=0.74 (95%CI 0.57-0.97)). Interventions targeting active commuting may promote cycling, and should take into account the differences regarding demographic variables. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Non-commutativity in polar coordinates

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, James P. [Universidad Michoacana de San Nicolas de Hidalgo, Ciudad Universitaria, Instituto de Fisica y Matematicas, Morelia, Michoacan (Mexico)

    2017-05-15

    We reconsider the fundamental commutation relations for non-commutative R{sup 2} described in polar coordinates with non-commutativity parameter θ. Previous analysis found that the natural transition from Cartesian coordinates to the traditional polar system led to a representation of [r, φ] as an everywhere diverging series. In this article we compute the Borel resummation of this series, showing that it can subsequently be extended throughout parameter space and hence provide an interpretation of this commutator. Our analysis provides a complete solution for arbitrary r and θ that reproduces the earlier calculations at lowest order and benefits from being generally applicable to problems in a two-dimensional non-commutative space. We compare our results to previous literature in the (pseudo-)commuting limit, finding a surprising spatial dependence for the coordinate commutator when θ >> r{sup 2}. Finally, we raise some questions for future study in light of this progress. (orig.)

  11. Simulation of Population-Based Commuter Exposure to NO2 Using Different Air Pollution Models

    Directory of Open Access Journals (Sweden)

    Martina S. Ragettli

    2014-05-01

    Full Text Available We simulated commuter routes and long-term exposure to traffic-related air pollution during commute in a representative population sample in Basel (Switzerland, and evaluated three air pollution models with different spatial resolution for estimating commute exposures to nitrogen dioxide (NO2 as a marker of long-term exposure to traffic-related air pollution. Our approach includes spatially and temporally resolved data on actual commuter routes, travel modes and three air pollution models. Annual mean NO2 commuter exposures were similar between models. However, we found more within-city and within-subject variability in annual mean (±SD NO2 commuter exposure with a high resolution dispersion model (40 ± 7 µg m−3, range: 21–61 than with a dispersion model with a lower resolution (39 ± 5 µg m−3; range: 24–51, and a land use regression model (41 ± 5 µg m−3; range: 24–54. Highest median cumulative exposures were calculated along motorized transport and bicycle routes, and the lowest for walking. For estimating commuter exposure within a city and being interested also in small-scale variability between roads, a model with a high resolution is recommended. For larger scale epidemiological health assessment studies, models with a coarser spatial resolution are likely sufficient, especially when study areas include suburban and rural areas.

  12. The association between access to public transportation and self-reported active commuting.

    Science.gov (United States)

    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.

  13. Impact of Survey Administration Mode on the Results of a Health-Related Discrete Choice Experiment : Online and Paper Comparison

    NARCIS (Netherlands)

    Determann, Domino; Lambooij, Mattijs S.; Steyerberg, Ewout W.; de Bekker-Grob, Esther W; de Wit, G Ardine|info:eu-repo/dai/nl/167546589

    2017-01-01

    BACKGROUND: Electronic data collection is increasingly being used for discrete choice experiments (DCEs). OBJECTIVES: To study whether paper or electronic administration results in measurement effects. METHODS: Respondents were drawn from the same sample frame (an Internet panel) and completed a

  14. Freight Demand Characteristics and Mode Choice: An Analysis of the Results of Modeling with Disaggregate Revealed Preference Data

    Science.gov (United States)

    1999-12-01

    This paper analyzes the freight demand characteristics that drive modal choice by means of a large scale, national, disaggregate revealed preference database for shippers in France in 1988, using a nested logit. Particular attention is given to priva...

  15. Does active commuting improve psychological wellbeing? Longitudinal evidence from eighteen waves of the British Household Panel Survey.

    Science.gov (United States)

    Martin, Adam; Goryakin, Yevgeniy; Suhrcke, Marc

    2014-12-01

    The aim of this study is to explore the relationship between active travel and psychological wellbeing. This study used data on 17,985 adult commuters in eighteen waves of the British Household Panel Survey (1991/2-2008/9). Fixed effects regression models were used to investigate how (i.) travel mode choice, (ii.) commuting time, and (iii.) switching to active travel impacted on overall psychological wellbeing and how (iv.) travel mode choice impacted on specific psychological symptoms included in the General Health Questionnaire. After accounting for changes in individual-level socioeconomic characteristics and potential confounding variables relating to work, residence and health, significant associations were observed between overall psychological wellbeing (on a 36-point Likert scale) and (i.) active travel (0.185, 95% CI: 0.048 to 0.321) and public transport (0.195, 95% CI: 0.035 to 0.355) when compared to car travel, (ii.) time spent (per 10minute change) walking (0.083, 95% CI: 0.003 to 0.163) and driving (-0.033, 95% CI: -0.064 to -0.001), and (iii.) switching from car travel to active travel (0.479, 95% CI: 0.199 to 0.758). Active travel was also associated with reductions in the odds of experiencing two specific psychological symptoms when compared to car travel. The positive psychological wellbeing effects identified in this study should be considered in cost-benefit assessments of interventions seeking to promote active travel. Copyright © 2014. Published by Elsevier Inc.

  16. On the interrelations between migration and commuting

    OpenAIRE

    Lukić Vesna

    2013-01-01

    In this paper, we emphasise the significance of studying the interrelations between commuting and migration. The aim of the paper is to point out the factors which affect these interrelations (demographic and socio-economic characteristics of migrants and commuters, labour market, real estate market, information, life style, etc.), with the special emphasis on the role of commuting distance onto the chosen mobility type. Besides theorethical frameworks and results of the selected foreig...

  17. Partially-commutative context-free languages

    OpenAIRE

    Sławomir Lasota; Wojciech Czerwiński

    2012-01-01

    The paper is about a class of languages that extends context-free languages (CFL) and is stable under shuffle. Specifically, we investigate the class of partially-commutative context-free languages (PCCFL), where non-terminal symbols are commutative according to a binary independence relation, very much like in trace theory. The class has been recently proposed as a robust class subsuming CFL and commutative CFL. This paper surveys properties of PCCFL. We identify a natural corresponding auto...

  18. Limits of Commutativity on Abstract Data Types

    OpenAIRE

    Malta, Carmelo; Martinez, José

    1992-01-01

    International audience; We present some formal properties of (symmetrical) commutativity, the major criterion used in transactional systems, which allow us to fully understand its advantages and disadvantages. The main result is that commutativity is subject to the same limitation as compatibility for arbitrary objects. However, commutativity has also a number of attracting properties, one of which is related to recovery and, to our knowledge, has not been exploited in the literature. Advanta...

  19. Relationship between commuting and health outcomes in a cross-sectional population survey in southern Sweden

    Directory of Open Access Journals (Sweden)

    Hansson Erik

    2011-10-01

    Full Text Available Abstract Background The need for a mobile workforce inevitably means that the length of the total work day (working and traveling time will increase, but the health effects of commuting have been surprisingly little studied apart from perceived stress and the benefits of physically active commuting. Methods We used data from two cross-sectional population-based public health surveys performed in 2004 and 2008 in Scania, Sweden (56% response rate. The final study population was 21, 088 persons aged 18-65, working > 30 h/week. Duration (one-way and mode of commuting were reported. The outcomes studied were perceived poor sleep quality, everyday stress, low vitality, mental health, self-reported health, and absence from work due to sickness during the past 12 months. Covariates indicating socioeconomic status and family situation, overtime, job strain and urban/rural residency were included in multivariate analyses. Subjects walking or cycling to work Results Monotonous relations were found between duration of public transport commuting and the health outcomes. For the category commuting > 60 min odds ratios (ORs ranged from 1.2 - 1.6 for the different outcomes. For car commuting, the relationships were concave downward or flat, with increasing subjective health complaints up to 30-60 min (ORs ranging from 1.2 - 1.4, and lower ORs in the > 60 min category. A similar concave downward relationship was observed for sickness absence, regardless of mode of transport. Conclusions The results of this study are concordant with the few earlier studies in the field, in that associations were found between commutation and negative health outcomes. This further demonstrates the need to consider the negative side-effects of commuting when discussing policies aimed at increasing the mobility of the workforce. Studies identifying population groups with increased susceptibility are warranted.

  20. Commutation failure at restart of an inverter

    Energy Technology Data Exchange (ETDEWEB)

    Bruntt, M.

    1997-12-31

    The sensitivity of commutation failures for an HVDC inverter due to AC voltage magnitude reduction and AC voltage distortion depends on the specific HVDC main circuit design and on the HVDC control system. There are ways to improve the immunity towards commutation failures, but they can never be completely avoided. This report deals with commutation failures at restart of an inverter, and does not consider the initial commutation failure. If the AC system after the fault is capable of absorbing the power from the restarting HVDC link without disturbing the AC voltage significantly, the HVDC link is back to normal operation after typically 50 to 200 ms after the fault is cleared. The stability of the connected AC systems is not seriously affected by this limited time period with lack or excess of power. This report deals with the idea of finding an indicator for the second commutation failure during restart. The process of commutation failures and furthermore commutation failures during restart are characterized. A network which is considered to be general is analysed to find indication of commutation failure during restart. Different potential indictors are examined. The effect of changing the general control parameters during the restart to help the recovery in critical situations is also examined. The analysis do, however, not give the answer to which parameters are the best to change because this question need to be answered for each specific case. Finally a specific network is analysed to find an indicator of a second commutation failure. (EG)

  1. Active Commuting to School as a Source of Health Promotion ...

    African Journals Online (AJOL)

    The students were predominantly passive commuters and their commuting pattern was linked to sociodemographic characteristics while barriers and facilitators of active commuting included family, societal, environmental and school factors. KEYWORDS: adolescents health, attitudes, physical activity, sociodemographic ...

  2. Prediction of Citizens’ Decisions on Transport Mode Choice in Bandung City, Indonesia by Using General Linear Model Given existing Level of Pedestrian Friendly Environment

    Directory of Open Access Journals (Sweden)

    Ariva Sugandi Permana

    2014-04-01

    Full Text Available 800x600 Significant contribution of non-motorized transport to energy and environment has changed the view of people on walking or cycling as one of transport modes. While promoting mass rapid transport, modern cities tend to promote pedestrianization as well to encourage people to walk instead of relying on motorized transport. Creating pedestrian friendly environment in particular parts of the city, especially in CBD, is one such attempt. This study tries to investigate the correlation between perceptions of the citizens on pedestrian friendly environment (PFE and their decision on the choices of transport modes. The central business district of Bandung City in Indonesia was chosen as the study area. A questionnaire-based research was used to acquire data on citizens’ perception. Eight variables were employed to understand citizens’ perception on PFE. The result shows that PFE does influence citizens’ decision on their transport modes choice. Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

  3. Systems and methods for commutating inductor current using a matrix converter

    Science.gov (United States)

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

    2012-10-16

    Systems and methods are provided for delivering current using a matrix converter in a vehicle. An electrical system comprises an AC interface, a first conversion module coupled to the AC interface, an inductive element coupled between the AC interface and the first conversion module, and a control module coupled to the first conversion module. The control module is configured to operate the first conversion module in a bidirectional operating mode to commutate current bidirectionally. When a magnitude of the current through the inductive element is greater than a first threshold value, the control module operates the conversion module in a unidirectional operating mode, wherein current is commutated unidirectionally.

  4. Measuring soft measures within a stated preference survey: The effect of pollution and traffic stress on mode choice

    DEFF Research Database (Denmark)

    Sottile, Eleonora; Cherchi, Elisabetta; Meloni, Italo

    2015-01-01

    . Results showed that the utility to Park and Ride increases with the level of awareness, 2) the more individuals consider receiving information about stress useful, the more they tend to behave sustainably, 3) aspects associated with stress appear to have a greater influence on travel choice than...... environmental aspects....

  5. Commuting-related fringe benefits in the Netherlands : Interrelationships and company, employee and location characteristics

    NARCIS (Netherlands)

    Nijland, Linda; Dijst, Martin

    2015-01-01

    Mobility management measures taken by firms could potentially result in more sustainable transport choices and hence reduce traffic congestion and emissions. Fringe benefits offered to employees are a means to implement those measures. This paper explores the most common commuting-related fringe

  6. Beyond the trailing spouse: The commuter partnership as an alternative to family migration

    NARCIS (Netherlands)

    van der Klis, M.; Mulder, C.H.

    2008-01-01

    Combining commitments in the domains of work, family, and residence has become a complex puzzle for the contemporary (dual-earner) family, especially when these choices concern family migration. For some families, non-standard alternatives to family migration, such as a commuter partnership in which

  7. Factors affecting commuter rail energy efficiency.

    Science.gov (United States)

    2016-02-17

    The objective of this study is to develop a planninglevel model of commuter rail energy efficiency. The : environmental benefits of commuter rail are often cited as one of the key benefits and motivators for its rapid development as a public trans...

  8. Choice of geometry and operating regimes for experimental dual-mode high-speed propane-fueled combustion chamber

    Science.gov (United States)

    Vlasenko, Vladimir; Voloshchenko, Oleg; Sabelnikov, Vladimir; Talyzin, Vadim

    2017-10-01

    The choice of geometry and operatic regimes of an experimental model of combustion chamber with a supersonic flow at the entrance is described. In this model, subsonic or supersonic combustion should be realized, depending on the inflow parameters. Propane will be used as fuel. The model combustor will be tested in T-131B wind tunnel of TsAGI. The goal is creation of experimental database for validation of calculations and physical models of turbulence and combustion. Geometry of chamber has similarities to geometry of model tested at ONERA LAERTE facility within LAPCAT-II project, but other flow regimes are considered. Preliminary 2D URANS calculations were used for the choice of fuel injection scheme. For the chosen flow regime, stabilization of combustion was not obtained for pure propane fuel. Addition of small portion of hydrogen allowed to stabilize the flame. Both subsonic and supersonic combustion regimes are found and analyzed.

  9. Take part in the Commute-Another-Way Challenge!

    CERN Multimedia

    CERN Bulletin

    2015-01-01

    Ring the changes on Thursday, 4 June by commuting another way! CERN has signed up for the 5th “challenge mobilité Rhône-Alpes”, the aim of which is to encourage people to use modes of transport other than their car to get to work. Are you up for the challenge?   Join in the challenge! Sign up using the dedicated CERN form. "Commute another way!" is an initiative launched by the Rhône-Alpes regional authorities and the French environment agency ADEME (l’Agence de l’environnement et de la maîtrise de l’énergie française) to promote alternative ways of travelling to work than the car (excluding carpooling), in private and public-sector organisations across the region. We love this idea and CERN has been signed up to a similar scheme - Bike to Work - for several years. That’s why we’ve decided that CERN should join the Commute-A...

  10. Intrinsic non-commutativity of closed string theory

    Science.gov (United States)

    Freidel, Laurent; Leigh, Robert G.; Minic, Djordje

    2017-09-01

    We show that the proper interpretation of the cocycle operators appearing in the physical vertex operators of compactified strings is that the closed string target is noncommutative. We track down the appearance of this non-commutativity to the Polyakov action of the flat closed string in the presence of translational monodromies (i.e., windings). In view of the unexpected nature of this result, we present detailed calculations from a variety of points of view, including a careful understanding of the consequences of mutual locality in the vertex operator algebra, as well as a detailed analysis of the symplectic structure of the Polyakov string. We also underscore why this non-commutativity was not emphasized previously in the existing literature. This non-commutativity can be thought of as a central extension of the zero-mode operator algebra, an effect set by the string length scale — it is present even in trivial backgrounds. Clearly, this result indicates that the α ' → 0 limit is more subtle than usually assumed.

  11. Neighbourhood, Route and Workplace-Related Environmental Characteristics Predict Adults' Mode of Travel to Work.

    Directory of Open Access Journals (Sweden)

    Alice M Dalton

    Full Text Available Commuting provides opportunities for regular physical activity which can reduce the risk of chronic disease. Commuters' mode of travel may be shaped by their environment, but understanding of which specific environmental characteristics are most important and might form targets for intervention is limited. This study investigated associations between mode choice and a range of objectively assessed environmental characteristics.Participants in the Commuting and Health in Cambridge study reported where they lived and worked, their usual mode of travel to work and a variety of socio-demographic characteristics. Using geographic information system (GIS software, 30 exposure variables were produced capturing characteristics of areas around participants' homes and workplaces and their shortest modelled routes to work. Associations between usual mode of travel to work and personal and environmental characteristics were investigated using multinomial logistic regression.Of the 1124 respondents, 50% reported cycling or walking as their usual mode of travel to work. In adjusted analyses, home-work distance was strongly associated with mode choice, particularly for walking. Lower odds of walking or cycling rather than driving were associated with a less frequent bus service (highest versus lowest tertile: walking OR 0.61 [95% CI 0.20-1.85]; cycling OR 0.43 [95% CI 0.23-0.83], low street connectivity (OR 0.22, [0.07-0.67]; OR 0.48 [0.26-0.90] and free car parking at work (OR 0.24 [0.10-0.59]; OR 0.55 [0.32-0.95]. Participants were less likely to cycle if they had access to fewer destinations (leisure facilities, shops and schools close to work (OR 0.36 [0.21-0.62] and a railway station further from home (OR 0.53 [0.30-0.93]. Covariates strongly predicted travel mode (pseudo r-squared 0.74.Potentially modifiable environmental characteristics, including workplace car parking, street connectivity and access to public transport, are associated with travel mode

  12. Investigation of Asymetric Modes of Three-phase Three - legs Phase-shifting Transformer with “Inverse Double Zigzag” Scheme of Windings Connections and Commutation in Neutral Point

    Directory of Open Access Journals (Sweden)

    Bosneaga V.A

    2015-04-01

    Full Text Available The model for power three-phase three limbs phase-shifting transformer with “inverse double zig-zag connection” was investigated. Calculations and research of steady state asymmetric modes of transformer with such windings connection were fulfilled, taking into account the electromagnetic coupling of the windings, located on different legs. The analysis was made for the most specific steady state asymmetric modes, that occur during different short circuits and asymmetric no load regimes, associated with the appearance of zero sequence magnetic flux. Vector diagrams for windings currents and voltages were constructed, as well as for the relative values of magnetic fluxes in legs, which in ensemble give a clear idea about their particularities.

  13. Characteristics of movement and factors affecting the choice of mode of transport of community on the bank of Musi River of Palembang City of South Sumatra

    Science.gov (United States)

    Arliansyah, Joni; Hartono, Yusuf; Hastuti, Yulia; Astuti, Rinna

    2017-11-01

    Palembang City is one of the cities having the largest river in Indonesia and it should be able to take advantage of river transportation as an alternative choice. Inadequate availability of river transport facilities and infrastructures makes the people prefer other modes of land transportation rather than using river transportation. In addition, the development planning of river transportation such as the development of river taxi is less successful because it is not yet based on the movement pattern of the origin of the community travel destination. Based on the above matter, this study was conducted. The aim of the study was to find out the characteristics and factors affecting the mode choice of the community living along the bank of Musi River of Palembang City to be the basis of the development of river transportation system in Palembang City. The selected modes were motorcycles, cars, city transports, and ketek (motorized boats). Survey of home interviews was conducted to determine the origin of the destination and characteristics of travel was conducted in 30 villages located on the banks of Musi River. Field survey was conducted to determine the conditions and types of existing river transportation facilities and services. The results show that only 5.3 % of the occurrence movement used river transportation, the rest used motorcycles (69.1%), urban transport (15.9 %) and cars (9.7%), with the travel range less than10 minutes and 10 - 20 minutes as much as 43.2 % and 29 % of the total trips. From the socioeconomic profile of the community, it is found that most of the people living along the Musi River have low and middle incomes with the largest types of jobs as workers, students, shop owner, and housewives. The peak movement time for the movement of river transport occurs at 7:00 - 8:00, 10:00 - 11:00 and 16:00 - 17:00 with the movement of origin of the destination of river transportation is known to be 50% at the traditional market center of Dermaga of

  14. THE DEVELOPMENT OF MODE-CHOICE SIMULATOR WITH THE LOG DATA ACCUMULATED IN ON-DEMAND BUS SERVER

    Science.gov (United States)

    Tsubouchi, Kota; Yamato, Hiroyuki; Hiekata, Kazuo

    The new simulator which can estimate the mode-choi ce in the area was developed and evaluated in the field test. The characteristic of the developed simulato r is to be able to estimate the number of demand and demand pattern in high-accuracy with the real operation log data of the On-demand Bus. The simulator is devided into micro-simulator whose passenger agents choose their transpor t mode by the sacrifice model. The developed simulator is evaluated in the real fi eld test in Sakai City, Osaka Prefecture. The new transportation like LRT (Light Rail Transit) and On-demand Bus is eval uated by the simulator and the result of simulation is confirmed to be reliable by the local government officers.

  15. Fertility and Commuting Behaviour in Germany

    Directory of Open Access Journals (Sweden)

    Johannes Huinink

    2012-12-01

    Firstly, a cross-sectional, multivariate probit-regression (with correlated errors on the intention to have a child within two years, on being childless and on medium- and long- distance commuting is applied. The model shows no significant correlation between commuting and the intention to have a child; it does however show a correlation between medium- and long distance commuting and the probability of women to be childless. Secondly, a longitudinal difference model on changing fertility intentions between panel wave 1 and wave 3 is estimated. For women, a positive effect can be found of interrupting medium- and long-distance commuting or, surprisingly, continuing medium- and long-distance commuting on the intention to have a child within two years. Thirdly, for men and women who reported a fertility intention in the first wave, a longitudinal Heckman-selection probit-regression on the probability of having a child between wave 1 and wave 3 is estimated. It shows negative effects of medium- and long-distance commuting on having a child. Taken together, these findings support the assumption that commuting plays a characteristically different role in different phases of the fertility-related decision process.

  16. Fostering Formal Commutativity Knowledge with Approximate Arithmetic.

    Directory of Open Access Journals (Sweden)

    Sonja Maria Hansen

    Full Text Available How can we enhance the understanding of abstract mathematical principles in elementary school? Different studies found out that nonsymbolic estimation could foster subsequent exact number processing and simple arithmetic. Taking the commutativity principle as a test case, we investigated if the approximate calculation of symbolic commutative quantities can also alter the access to procedural and conceptual knowledge of a more abstract arithmetic principle. Experiment 1 tested first graders who had not been instructed about commutativity in school yet. Approximate calculation with symbolic quantities positively influenced the use of commutativity-based shortcuts in formal arithmetic. We replicated this finding with older first graders (Experiment 2 and third graders (Experiment 3. Despite the positive effect of approximation on the spontaneous application of commutativity-based shortcuts in arithmetic problems, we found no comparable impact on the application of conceptual knowledge of the commutativity principle. Overall, our results show that the usage of a specific arithmetic principle can benefit from approximation. However, the findings also suggest that the correct use of certain procedures does not always imply conceptual understanding. Rather, the conceptual understanding of commutativity seems to lag behind procedural proficiency during elementary school.

  17. Exploratory mapping of commuter flows in England and Wales

    DEFF Research Database (Denmark)

    Nielsen, Thomas Alexander Sick; Harder, Henrik

    2008-01-01

    The paper uses the origin–destination commute data published from the 1991 and 2001 Census to explore the developments in commuting and interaction patterns within England and Wales. Focus is on the geographical variations and a map of commuter flows is presented. Commuting is stretched out along...

  18. Daily Commute Time Prediction Based on Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Fang Zong

    2012-01-01

    Full Text Available This paper presents a joint discrete-continuous model for activity-travel time allocation by employing the ordered probit model for departure time choice and the hazard model for travel time prediction. Genetic algorithm (GA is employed for optimizing the parameters in the hazard model. The joint model is estimated using data collected in Beijing, 2005. With the developed model, departure and travel times for the daily commute trips are predicted and the influence of sociodemographic variables on activity-travel timing decisions is analyzed. Then the whole time allocation for the typical daily commute activities and trips is derived. The results indicate that the discrete choice model and the continuous model match well in the calculation of activity-travel schedule. The results also show that the genetic algorithm contributes to the optimization and thus the high accuracy of the hazard model. The developed joint discrete-continuous model can be used to predict the agenda of a simple daily activity-travel pattern containing only work, and it provides potential for transportation demand management policy analysis.

  19. Associations between environmental characteristics and active commuting to school among children: a cross-sectional study

    NARCIS (Netherlands)

    Aarts, M.J.; Mathijssen, J.J.J.P.; van Oers, J.A.M.; Schuit, A.J.

    2013-01-01

    Background: Active commuting to school can contribute to active living among children, and environmental characteristics might be related to transportation mode to school. Purpose: The purpose of this study is to explore the association between physical and social environmental characteristics in

  20. Associations between environmental characteristics and active commuting to school among children : A cross-sectional study

    NARCIS (Netherlands)

    Aarts, M.J.; Mathijssen, J.J.P.; van Oers, J.A.M.; Schuit, A.J.

    2013-01-01

    Background Active commuting to school can contribute to active living among children, and environmental characteristics might be related to transportation mode to school. Purpose The purpose of this study is to explore the association between physical and social environmental characteristics in the

  1. The theory of finitely generated commutative semigroups

    CERN Document Server

    Rédei, L; Stark, M; Gravett, K A H

    1966-01-01

    The Theory of Finitely Generated Commutative Semigroups describes a theory of finitely generated commutative semigroups which is founded essentially on a single """"fundamental theorem"""" and exhibits resemblance in many respects to the algebraic theory of numbers. The theory primarily involves the investigation of the F-congruences (F is the the free semimodule of the rank n, where n is a given natural number). As applications, several important special cases are given. This volume is comprised of five chapters and begins with preliminaries on finitely generated commutative semigroups before

  2. On the interrelations between migration and commuting

    Directory of Open Access Journals (Sweden)

    Lukić Vesna

    2013-01-01

    Full Text Available In this paper, we emphasise the significance of studying the interrelations between commuting and migration. The aim of the paper is to point out the factors which affect these interrelations (demographic and socio-economic characteristics of migrants and commuters, labour market, real estate market, information, life style, etc., with the special emphasis on the role of commuting distance onto the chosen mobility type. Besides theorethical frameworks and results of the selected foreign researches up to date, the overview of research of interrelations between migration and commuting in Serbia has also been presented. While earlier studies conducted by Gawryszenski (1978, Termote (1980 and Reitsma&Vergoossen (1987 pointed to the replacement of migration types between each other within country, in recent literature the interaction between migration and commuting has been studied in a trans-boundary context of the contemporary EU. Modern trend of long distance commuting instead of migration and the concept of substitution/replacement regarding migration and commuting have also been discussed. In Serbia, there is a positive correlation between commuting outflows and immigration in rural settlements of Vojvodina province. Namely, commuting and migration are complement, which is the characteristic of both processes sub-urbanisation and ex-urbanisation (Lukić, 2012. In addition to ownership of real estate and previous migration experience, marital status influenced the chosen mobility type in Serbia as well. Adjustment to changes of Serbian labour market is mostly conducted via migration (Miletić, Lukić, Miljanović, 2011. Interrelations between migration and commuting are very significant due to the tendency of transformation of some commuters into migrants. This process has its consequences, both on demographic as well as the overall socio-economic development of the area of commuters’ origin and destination. However, even though the surveys

  3. Congestion Behavior under Uncertainty on Morning Commute with Preferred Arrival Time Interval

    Directory of Open Access Journals (Sweden)

    LingLing Xiao

    2014-01-01

    Full Text Available This paper extends the bottleneck model to study congestion behavior of morning commute with flexible work schedule. The proposed model assumes a stochastic bottleneck capacity which follows a uniform distribution and homogeneous commuters who have the same preferred arrival time interval. The commuters are fully aware of the stochastic properties of travel time and schedule delay distributions at all departure times that emerge from day-to-day capacity variations. The commuters’ departure time choice follows user equilibrium (UE principle in terms of the expected trip cost. Analytical and numerical solutions of this model are provided. The equilibrium departure time patterns are examined which show that the stochastic capacity increases the mean trip cost and lengthens the rush hour. The adoption of flexitime results in less congestion and more efficient use of bottleneck capacity than fixed-time work schedule. The longer the flexi-time interval is, the more uniformly distributed the departure times are.

  4. Finding the right RoPax vessel size and freight price. A coste and mode choice model

    Energy Technology Data Exchange (ETDEWEB)

    Morales Fusco, P.; Grau Sala, M.; Sauri Marchan, S.

    2016-07-01

    Motorways of the sea operated as RoPax services are natural competitors with only-road freight haulage transportation. Cost, time and quality perceived are the determinants that make transporters and shippers use one route or another. This research considers the role that shipping companies and their ship deployment and pricing strategy have in the equation, as incentives for modal shift from road to sea. A model of the ships and transporter costs is developed considering different business models for the transporter (accompanied versus unaccompanied cargo) followed with a discrete choice model that, once calibrated, allows to test the influence that variables such as frequency, ship size and commercial speed might play into the competitiveness of a shipping line. As a result, different pricing strategies for the shipping line are developed and the characteristics of the optimal shipping line for each of them are found, to either maximize the profit of the shipping company or the modal shift. (Author)

  5. Gender differences in commuting behavior: Women's greater sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Olmo Sanchez, M.I.; Maeso Gonzalez, E.

    2016-07-01

    Women's greater sensitivity to changes in their environment is one of the most distinguishing features between both genders. This article raises women's greater sensitivity to the different variables which influence their commuting modal choice. In order to do this, gender gaps detected in the choice of means of transport in commuting trips with respect to the decision factors such as age, education level, driver's license, private transport access; location, household size and net income, are quantified.The results show a greater female sensitivity to the different variables that affect their modal choice, which helps to better understand the different mobility patterns and it is useful for planning measures favoring sustainable mobility policies and equity. (Author)

  6. Determinants of self-employment among commuters and non-commuters

    DEFF Research Database (Denmark)

    Backman, M.; Karlsson, C.

    2016-01-01

    We analyse the determinants of self-employment and focus on the contextual environment. By distinguishing between commuters and non-commuters we are able to analyse the influence from the work and home environment, respectively. Our results indicate a significant difference between non......-commuters and commuters in terms of the role of networks for becoming self-employed. Our results indicate that it is the business networks where people work, rather than where they live that exerts a positive influence on the probability of becoming self-employed. These effects are further robust over educational...

  7. Foundations of commutative rings and their modules

    CERN Document Server

    Wang, Fanggui

    2016-01-01

    This book provides an introduction to the basics and recent developments of commutative algebra. A glance at the contents of the first five chapters shows that the topics covered are ones that usually are included in any commutative algebra text. However, the contents of this book differ significantly from most commutative algebra texts: namely, its treatment of the Dedekind–Mertens formula, the (small) finitistic dimension of a ring, Gorenstein rings, valuation overrings and the valuative dimension, and Nagata rings. Going further, Chapter 6 presents w-modules over commutative rings as they can be most commonly used by torsion theory and multiplicative ideal theory. Chapter 7 deals with multiplicative ideal theory over integral domains. Chapter 8 collects various results of the pullbacks, especially Milnor squares and D+M constructions, which are probably the most important example-generating machines. In Chapter 9, coherent rings with finite weak global dimensions are probed, and the local ring of weak gl...

  8. Cq-commuting maps and invariant approximations

    Directory of Open Access Journals (Sweden)

    B. E. Rhoades

    2006-06-01

    Full Text Available We obtain common fixed point results for generalized I-nonexpansive Cq-commuting maps. As applications, various best approximation results for this class of maps are derived in the setup of certain metrizable topological vector spaces.

  9. Covariant non-commutative space–time

    Directory of Open Access Journals (Sweden)

    Jonathan J. Heckman

    2015-05-01

    Full Text Available We introduce a covariant non-commutative deformation of 3+1-dimensional conformal field theory. The deformation introduces a short-distance scale ℓp, and thus breaks scale invariance, but preserves all space–time isometries. The non-commutative algebra is defined on space–times with non-zero constant curvature, i.e. dS4 or AdS4. The construction makes essential use of the representation of CFT tensor operators as polynomials in an auxiliary polarization tensor. The polarization tensor takes active part in the non-commutative algebra, which for dS4 takes the form of so(5,1, while for AdS4 it assembles into so(4,2. The structure of the non-commutative correlation functions hints that the deformed theory contains gravitational interactions and a Regge-like trajectory of higher spin excitations.

  10. Partially-commutative context-free languages

    Directory of Open Access Journals (Sweden)

    Sławomir Lasota

    2012-08-01

    Full Text Available The paper is about a class of languages that extends context-free languages (CFL and is stable under shuffle. Specifically, we investigate the class of partially-commutative context-free languages (PCCFL, where non-terminal symbols are commutative according to a binary independence relation, very much like in trace theory. The class has been recently proposed as a robust class subsuming CFL and commutative CFL. This paper surveys properties of PCCFL. We identify a natural corresponding automaton model: stateless multi-pushdown automata. We show stability of the class under natural operations, including homomorphic images and shuffle. Finally, we relate expressiveness of PCCFL to two other relevant classes: CFL extended with shuffle and trace-closures of CFL. Among technical contributions of the paper are pumping lemmas, as an elegant completion of known pumping properties of regular languages, CFL and commutative CFL.

  11. Developing a methodology for projecting intercity commuting.

    Science.gov (United States)

    2015-12-01

    Texas agencies are investigating passenger rail options in several corridors connecting people : between the states major cities. Popular thinking is that there is commuter travel between a : number of these markets. In specific, Austin to Houston...

  12. Pedestrian and bicyclist motivation: an assessment of influences on pedestrians’ and bicyclists’ mode choice in Mt. Pleasant, Vancouver

    Directory of Open Access Journals (Sweden)

    Jeffery M. Guinn

    2014-01-01

    Full Text Available The majority of short distance travel in North America is completed by single occupancy vehicles. Substituting walking and bicycling for these trips would reduce energy use and environmental pollution, while improving quality of life. Therefore, understanding influences on non-automotive travel behavior is crucial. Researchers and planners have touted specific factors for encouraging walking and biking, but the body of work remains fragmented. Previous studies have focused on a smaller number of factors and most of them relate to physical design. This study tests the relative importance of a range of factors, both physical and perceptual that could influence one’s choice to walk or bike. The Mt. Pleasant neighborhood in Vancouver, B.C., Canada was chosen as the location for this study as all of the pedestrian-motivating factors identified in a literature review were present. A questionnaire-based survey addressing distance, sidewalks/bike lanes, pedestrian/bicycle traffic signals, buffering from auto traffic, sense of security, cleanliness, opportunities to talk with others, enforcement of traffic laws, concern for the environment, weather, terrain, saving money, opportunities for exercise, and a visually appealing environment as influential factors was administered in person and online yielding 774 responses. All factors were shown to influence the decision to walk or bike, but some proved more significant than others, especially opportunities for exercise.

  13. The choice of baby feeding mode within the reality of the HIV/AIDS epidemic: health education implications.

    Science.gov (United States)

    Minnie, C S; Greeff, M

    2006-11-01

    Avoidance of breast-feeding rules out the risk of HIV-transmission, but is not the best choice for all women. Pregnant women can be empowered by health education to make an informed decision. The aims of this study were to explore and describe the factors that should be considered in health education on HIV and baby feeding as well as the perceptions and knowledge-levels of midwives and pregnant women regarding these factors. The final aim was to compile guidelines for health education to pregnant women. A quantitative survey design utilizing structured questionnaires was used. An all-inclusive sample of 17 midwives working in antenatal clinics in the Potchefstroom district in South Africa and an availability sample of 93 pregnant women visiting these clinics participated. It was found that, although the midwives have a basic knowledge of HIV and baby feeding, there are specific knowledge-gaps related to the latest trends and research. The existing knowledge of the midwives was not efficiently conveyed to the pregnant women and they were not sufficiently empowered to make an informed decision. Recommendations were formulated for nursing education and research with the focus on recommendations for practice. These guidelines include factors conducive to a positive milieu, as well as the presentation and content of health education.

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

    Science.gov (United States)

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

    2014-11-01

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

  15. Roadside observation of secondary school students' commuting to school in Vientiane, Laos.

    Science.gov (United States)

    Ichikawa, Masao; Nakahara, Shinji; Phommachanh, Sysavanh; Mayxay, Mayfong; Kimura, Akio

    2015-01-01

    To investigate modes of secondary school students' commuting to school and their unsafe driving practices in Laos, we conducted a roadside observation in front of the gate of a selected school in central Vientiane in December 2011. Of the 544 students observed, the majority came to school on foot (43%), followed by motorcycle (36%), and bicycle (14%). Of the 195 students who commuted by motorcycle, 45 (23%) drove it themselves. Of the 150 students who commuted as pillion riders, 35 (23%) were driven by a student or another child driver. The prevalence of helmet use among students (3%) was much lower than adults (66%). It was common for adult drivers to wear a helmet but to leave student pillion riders unhelmeted on the same motorcycle. Carrying two or three pillion riders was also often observed. The study revealed the necessity for measures to promote safe travel to school.

  16. Associations between the duration of active commuting to school and academic achievement in rural Chilean adolescents.

    Science.gov (United States)

    García-Hermoso, Antonio; Saavedra, Jose M; Olloquequi, Jordi; Ramírez-Vélez, Robinson

    2017-04-04

    Habitual active commuting to school may be positively associated with academic achievement. The aim of this study was to examine the relationship between duration of walking or otherwise actively commuting to school and academic achievement. This cross-sectional study included 389 adolescents from seven rural schools (12-13 years). Mode and duration of active commuting to school (use of active means such as walking or biking to and from school) and screen time were self-reported. Academic achievement was determined by the outcome in basic grades (language and mathematics). Active commuting to school was not associated with higher scores in any grades after adjustment for potential confounders. No evidence was found of interactions between gender and academic achievement, but there was interaction with duration of walking (60 min). Adjusted binary logistic regression analysis suggested that adolescents who spent between 30 and 60 min actively commuting were more likely to obtain high academic achievement (language and mathematics). Thirty to 60 min of ACS may have a positive influence on academic achievement in adolescents, so, it is necessary to make recommendations for the children to walk from and/or to school. This could help society to recognize the relevance of physical activity to health as well as to academic performance.

  17. Relationship between commuting and health outcomes in a cross-sectional population survey in southern Sweden.

    Science.gov (United States)

    Hansson, Erik; Mattisson, Kristoffer; Björk, Jonas; Östergren, Per-Olof; Jakobsson, Kristina

    2011-10-31

    The need for a mobile workforce inevitably means that the length of the total work day (working and traveling time) will increase, but the health effects of commuting have been surprisingly little studied apart from perceived stress and the benefits of physically active commuting. We used data from two cross-sectional population-based public health surveys performed in 2004 and 2008 in Scania, Sweden (56% response rate). The final study population was 21, 088 persons aged 18-65, working > 30 h/week. Duration (one-way) and mode of commuting were reported. The outcomes studied were perceived poor sleep quality, everyday stress, low vitality, mental health, self-reported health, and absence from work due to sickness during the past 12 months. Covariates indicating socioeconomic status and family situation, overtime, job strain and urban/rural residency were included in multivariate analyses. Subjects walking or cycling to work 60 min odds ratios (ORs) ranged from 1.2 - 1.6 for the different outcomes. For car commuting, the relationships were concave downward or flat, with increasing subjective health complaints up to 30-60 min (ORs ranging from 1.2 - 1.4), and lower ORs in the > 60 min category. A similar concave downward relationship was observed for sickness absence, regardless of mode of transport. The results of this study are concordant with the few earlier studies in the field, in that associations were found between commutation and negative health outcomes. This further demonstrates the need to consider the negative side-effects of commuting when discussing policies aimed at increasing the mobility of the workforce. Studies identifying population groups with increased susceptibility are warranted.

  18. Survey of how staff commute to work

    CERN Multimedia

    2014-01-01

    A survey was initiated by the Canton of Geneva (Direction Générale des Transports) and the Swiss Permanent Mission to the United Nations, and is aimed at better understanding how staff in International Organisations commute to/from work so as to better plan future works (road access, public transport, etc.). The ILO, WHO, UNAIDs, Global Fund, IFRC, CERN and UNOG are taking part in this important survey.   People living in Switzerland or France are invited to respond to this survey. The purpose of this survey is to better understand: - your commuting habits, - your willingness to explore alternative commuting options, - your expectations and needs. All data provided to this external company (www.mobilidee.ch) will be kept confidential and will only be used for this particular study. CERN has received all guarantees of confidentiality from this company. Many thanks for your collaboration! GS Department

  19. Non-Hamiltonian commutators in quantum mechanics.

    Science.gov (United States)

    Sergi, Alessandro

    2005-12-01

    The symplectic structure of quantum commutators is first unveiled and then exploited to describe generalized non-Hamiltonian brackets in quantum mechanics. It is easily recognized that quantum-classical systems are described by a particular realization of such a bracket. In light of previous work, this paper explains a unified approach to classical and quantum-classical non-Hamiltonian dynamics. In order to illustrate the use of non-Hamiltonian commutators, it is shown how to define thermodynamic constraints in quantum-classical systems. In particular, quantum-classical Nosé-Hoover equations of motion and the associated stationary density matrix are derived. The non-Hamiltonian commutators for both Nosé-Hoover chains and Nosé-Andersen (constant-pressure, constant-temperature) dynamics are also given. Perspectives of the formalism are discussed.

  20. Commutative algebra constructive methods finite projective modules

    CERN Document Server

    Lombardi, Henri

    2015-01-01

    Translated from the popular French edition, this book offers a detailed introduction to various basic concepts, methods, principles, and results of commutative algebra. It takes a constructive viewpoint in commutative algebra and studies algorithmic approaches alongside several abstract classical theories. Indeed, it revisits these traditional topics with a new and simplifying manner, making the subject both accessible and innovative. The algorithmic aspects of such naturally abstract topics as Galois theory, Dedekind rings, Prüfer rings, finitely generated projective modules, dimension theory of commutative rings, and others in the current treatise, are all analysed in the spirit of the great developers of constructive algebra in the nineteenth century. This updated and revised edition contains over 350 well-arranged exercises, together with their helpful hints for solution. A basic knowledge of linear algebra, group theory, elementary number theory as well as the fundamentals of ring and module theory is r...

  1. Towards a differentiated understanding of active travel behaviour: Using social theory to explore everyday commuting

    OpenAIRE

    Guell, C.; Panter, J.; Jones, N.R.; Ogilvie, D.

    2012-01-01

    Fostering physical activity is an established public health priority for the primary prevention of a variety of chronic diseases. One promising population approach is to seek to embed physical activity in everyday lives by promoting walking and cycling to and from work (?active commuting?) as an alternative to driving. Predominantly quantitative epidemiological studies have investigated travel behaviours, their determinants and how they may be changed towards more active choices. This study a...

  2. Commutability of food microbiology proficiency testing samples.

    Science.gov (United States)

    Abdelmassih, M; Polet, M; Goffaux, M-J; Planchon, V; Dierick, K; Mahillon, J

    2014-03-01

    Food microbiology proficiency testing (PT) is a useful tool to assess the analytical performances among laboratories. PT items should be close to routine samples to accurately evaluate the acceptability of the methods. However, most PT providers distribute exclusively artificial samples such as reference materials or irradiated foods. This raises the issue of the suitability of these samples because the equivalence-or 'commutability'-between results obtained on artificial vs. authentic food samples has not been demonstrated. In the clinical field, the use of noncommutable PT samples has led to erroneous evaluation of the performances when different analytical methods were used. This study aimed to provide a first assessment of the commutability of samples distributed in food microbiology PT. REQUASUD and IPH organized 13 food microbiology PTs including 10-28 participants. Three types of PT items were used: genuine food samples, sterile food samples and reference materials. The commutability of the artificial samples (reference material or sterile samples) was assessed by plotting the distribution of the results on natural and artificial PT samples. This comparison highlighted matrix-correlated issues when nonfood matrices, such as reference materials, were used. Artificially inoculated food samples, on the other hand, raised only isolated commutability issues. In the organization of a PT-scheme, authentic or artificially inoculated food samples are necessary to accurately evaluate the analytical performances. Reference materials, used as PT items because of their convenience, may present commutability issues leading to inaccurate penalizing conclusions for methods that would have provided accurate results on food samples. For the first time, the commutability of food microbiology PT samples was investigated. The nature of the samples provided by the organizer turned out to be an important factor because matrix effects can impact on the analytical results. © 2013

  3. The Urbanik generalized convolutions in the non-commutative ...

    Indian Academy of Sciences (India)

    commutative probability; q-deformed convolution; weakly stable measure. 1. Introduction. In classical probability the convolution is an associative and commutative operation which preserves probability measures on the real line R. An alternative ...

  4. Examining the Link Between Public Transit Use and Active Commuting

    Directory of Open Access Journals (Sweden)

    Melissa Bopp

    2015-04-01

    Full Text Available Background: An established relationship exists between public transportation (PT use and physical activity. However, there is limited literature that examines the link between PT use and active commuting (AC behavior. This study examines this link to determine if PT users commute more by active modes. Methods: A volunteer, convenience sample of adults (n = 748 completed an online survey about AC/PT patterns, demographic, psychosocial, community and environmental factors. t-test compared differences between PT riders and non-PT riders. Binary logistic regression analyses examined the effect of multiple factors on AC and a full logistic regression model was conducted to examine AC. Results: Non-PT riders (n = 596 reported less AC than PT riders. There were several significant relationships with AC for demographic, interpersonal, worksite, community and environmental factors when considering PT use. The logistic multivariate analysis for included age, number of children and perceived distance to work as negative predictors and PT use, feelings of bad weather and lack of on-street bike lanes as a barrier to AC, perceived behavioral control and spouse AC were positive predictors. Conclusions: This study revealed the complex relationship between AC and PT use. Further research should investigate how AC and public transit use are related.

  5. Examining the link between public transit use and active commuting.

    Science.gov (United States)

    Bopp, Melissa; Gayah, Vikash V; Campbell, Matthew E

    2015-04-17

    An established relationship exists between public transportation (PT) use and physical activity. However, there is limited literature that examines the link between PT use and active commuting (AC) behavior. This study examines this link to determine if PT users commute more by active modes. A volunteer, convenience sample of adults (n = 748) completed an online survey about AC/PT patterns, demographic, psychosocial, community and environmental factors. t-test compared differences between PT riders and non-PT riders. Binary logistic regression analyses examined the effect of multiple factors on AC and a full logistic regression model was conducted to examine AC. Non-PT riders (n = 596) reported less AC than PT riders. There were several significant relationships with AC for demographic, interpersonal, worksite, community and environmental factors when considering PT use. The logistic multivariate analysis for included age, number of children and perceived distance to work as negative predictors and PT use, feelings of bad weather and lack of on-street bike lanes as a barrier to AC, perceived behavioral control and spouse AC were positive predictors. This study revealed the complex relationship between AC and PT use. Further research should investigate how AC and public transit use are related.

  6. Soft-commutated direct current motor

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, J.S.

    1999-07-27

    A method and circuit is disclosed for soft-commutation of a direct current (DC) motor. An attenuation circuit is connected through auxiliary brushes A, A[prime], B and B[prime] to the commutator (16) to drain circuit from successive armature coils (15) before the main brushes (27, 28) disconnects from each of the coils (15). This prevents the spark generation that normally occurs in conventional DC motors. The attenuation circuit may also be connected before energization of the coil (15) for a soft turning on operation. 13 figs.

  7. Soft-commutated direct current motor

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, John S. (Oak Ridge, TN)

    1999-01-01

    A method and circuit is disclosed for soft-commutation of a direct current (DC) motor. An attenuation circuit is connected through auxiliary brushes A, A', B and B' to the commutator (16) to drain circuit from successive armature coils (15) before the main brushes (27, 28) disconnects from each of the coils (15). This prevents the spark generation that normally occurs in conventional DC motors. The attenuation circuit may also be connected before energization of the coil (15) for a soft turning on operation.

  8. Opinions of the commuters to receive oral health messages in South central railway zone India: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    P Parthasarathi Reddy

    2015-01-01

    Full Text Available Introduction: The railroads of India are the fourth most heavily used system in the world. Railways are one of the main modes of transport and millions of people travel by train daily. Aim: To know the opinions of commuters in receiving oral health messages in railways station through various methods and also their knowledge and practice regarding oral hygiene. Materials and Methods: Using convenient sampling method data from the commuters was obtained by a pretested questionnaire through interview method from 14 railway stations of South Central Railway zone. Pearson Chi-square test was used to compare the opinions of commuters based on their gender to receive oral health messages. Results: A total of 596 (97.3% responded to the survey; a maximum of 297 (49.8% subjects strongly agreed to the statement that railway platforms should have informative posters on oral health. A maximum of 188 (31.5% commuters strongly agreed that prerecorded messages on oral health if played before the announcement of arrival and departure of train will be helpful to spread oral health awareness. Majority of 43% commuters (255 preferred to receive oral hygiene instructions printed on back side of the ticket followed by messages on television and through posters. Conclusion: Majority of the commuters preferred to receive oral health information in railways stations. Hence, efforts can be directed in spreading oral health information among public through railways.

  9. Coping with employment issues through commuting: Evidence from Central Russia

    Directory of Open Access Journals (Sweden)

    Gunko Maria

    2017-06-01

    Full Text Available Commuting to work has become a widespread practice over the last several decades. Some relatively strong employment issues in rural Russian municipalities, as well as a significant wage gap between them and the major cities, fosters daily commuting as well as commuting with long periods of time spent at employment locations, known in Russia as otkhodnichestvo. Based on official statistical data and our own surveys conducted in Tula and Kostroma regions, we analysed the spatial differentiations between the share of commuters in the employed population of rural municipalities, as well as the variations in individual socio-economic characteristics between rural commuters and non-commuters, in general, and between the commuters themselves. Our analysis of the latter characteristics suggests that there is in fact more difference between the rural commuters and non-commuters in Russia than between daily commuters and those engaged in otkhodnichestvo, indicating similar motives and, perhaps, even personalities of commuters. Giving the identified differences, commuting on a larger scale does not seem to be a universal tool to cope with employment issues, as some population groups are more likely to engage in it than others.

  10. Commutating Permanent-Magnet Motors At Low Speed

    Science.gov (United States)

    Dolland, C.

    1985-01-01

    Circuit provides forced commutation during starting. Forced commutation circuit diverts current from inverter SCR's and turns SCR's off during commutation intervals. Silicon controlled rectifier in circuit unnecessary when switch S10 replaced by high-current, high-voltage transistor. At present, high-current, low-voltage device must suffice.

  11. Active commuting to school in Portuguese adolescents

    DEFF Research Database (Denmark)

    Pizarro, Andreia Nogueira; Schipperijn, Jasper; Andersen, Henriette Bondo

    2016-01-01

    Abstract The declining levels of physical activity (PA) have led to active commuting to school (ACS) being seen as a key strategy to increase PA levels in school-aged children. In Portugal, no data exists on the patterns of this behavior, an essential step for developing evidence-based and effect...

  12. Strong commutativity preserving generalized derivations on ...

    African Journals Online (AJOL)

    ... standard polynomial identity on 4 non-commuting variables, then there exist s; c ∈ U such that F(x) = xs, G(x) = cx, for all x ∈ R, and sc = 1C (the unit of C). We also study the semiprime case. Mathematics Subject Classification (2010): 16W25, 16N60. Key words: Prime rings, differential identities, generalized derivations.

  13. Happiness and Satisfaction with Work Commute

    NARCIS (Netherlands)

    Olsson, L.E.; Gärling, T.; Ettema, D.F.; Friman, M.; Fujii, S.

    2012-01-01

    Research suggests that for many people happiness is being able to make the routines of everyday life work, such that positive feelings dominate over negative feelings resulting from daily hassles. In line with this, a survey of work commuters in the three largest urban areas of Sweden show that

  14. Examining individuals' desire for shorter commute: the case of proximate commuting

    OpenAIRE

    Daniel A Rodríguez

    2002-01-01

    Much of the theoretical and empirical debate about transport and land-use planning has focused upon the strength and vitality of the connection between the two. Studies increasingly find that this connection is weakening and thus attempts to address urban transport problems with land-use policies are ineffective. The author introduces proximate commuting, a novel employer-based program that decreases urban commuting by providing marginal accessibility improvements to its participants. With th...

  15. Evaluating In-Car Movements in the Design of Mindful Commute Interventions: Exploratory Study

    Science.gov (United States)

    Hamdan, Nur Al-Huda; Clark, Dav; Cai, Carrie; Ju, Wendy; Landay, James A

    2017-01-01

    Background The daily commute could be a right moment to teach drivers to use movement or breath towards improving their mental health. Long commutes, the relevance of transitioning from home to work, and vice versa and the privacy of commuting by car make the commute an ideal scenario and time to perform mindful exercises safely. Whereas driving safety is paramount, mindful exercises might help commuters decrease their daily stress while staying alert. Increasing vehicle automation may present new opportunities but also new challenges. Objective This study aimed to explore the design space for movement-based mindful interventions for commuters. We used qualitative analysis of simulated driving experiences in combination with simple movements to obtain key design insights. Methods We performed a semistructured viability assessment in 2 parts. First, a think-aloud technique was used to obtain information about a driving task. Drivers (N=12) were given simple instructions to complete movements (configural or breath-based) while engaged in either simple (highway) or complex (city) simulated urban driving tasks using autonomous and manual driving modes. Then, we performed a matching exercise where participants could experience vibrotactile patterns from the back of the car seat and map them to the prior movements. Results We report a summary of individual perceptions concerning different movements and vibrotactile patterns. Beside describing situations within a drive when it may be more likely to perform movement-based interventions, we also describe movements that may interfere with driving and those that may complement it well. Furthermore, we identify movements that could be conducive to a more relaxing commute and describe vibrotactile patterns that could guide such movements and exercises. We discuss implications for design such as the influence of driving modality on the adoption of movement, need for personal customization, the influence that social perception

  16. Evaluating In-Car Movements in the Design of Mindful Commute Interventions: Exploratory Study.

    Science.gov (United States)

    Paredes, Pablo Enrique; Hamdan, Nur Al-Huda; Clark, Dav; Cai, Carrie; Ju, Wendy; Landay, James A

    2017-12-04

    The daily commute could be a right moment to teach drivers to use movement or breath towards improving their mental health. Long commutes, the relevance of transitioning from home to work, and vice versa and the privacy of commuting by car make the commute an ideal scenario and time to perform mindful exercises safely. Whereas driving safety is paramount, mindful exercises might help commuters decrease their daily stress while staying alert. Increasing vehicle automation may present new opportunities but also new challenges. This study aimed to explore the design space for movement-based mindful interventions for commuters. We used qualitative analysis of simulated driving experiences in combination with simple movements to obtain key design insights. We performed a semistructured viability assessment in 2 parts. First, a think-aloud technique was used to obtain information about a driving task. Drivers (N=12) were given simple instructions to complete movements (configural or breath-based) while engaged in either simple (highway) or complex (city) simulated urban driving tasks using autonomous and manual driving modes. Then, we performed a matching exercise where participants could experience vibrotactile patterns from the back of the car seat and map them to the prior movements. We report a summary of individual perceptions concerning different movements and vibrotactile patterns. Beside describing situations within a drive when it may be more likely to perform movement-based interventions, we also describe movements that may interfere with driving and those that may complement it well. Furthermore, we identify movements that could be conducive to a more relaxing commute and describe vibrotactile patterns that could guide such movements and exercises. We discuss implications for design such as the influence of driving modality on the adoption of movement, need for personal customization, the influence that social perception has on participants, and the potential

  17. Motivations for active commuting: a qualitative investigation of the period of home or work relocation

    Directory of Open Access Journals (Sweden)

    Jones Caroline HD

    2012-09-01

    Full Text Available Abstract Background Promoting walking or cycling to work (active commuting could help to increase population physical activity levels. According to the habit discontinuity and residential self-selection hypotheses, moving home or workplace is a period when people (reassess, and may be more likely to change, their travel behavior. Research in this area is dominated by the use of quantitative research methods, but qualitative approaches can provide in-depth insight into the experiences and processes of travel behavior change. This qualitative study aimed to explore experiences and motivations regarding travel behavior around the period of relocation, in an effort to understand how active commuting might be promoted more effectively. Methods Participants were recruited from the Commuting and Health in Cambridge study cohort in the UK. Commuters who had moved home, workplace or both between 2009 and 2010 were identified, and a purposive sample was invited to participate in semi-structured interviews regarding their experiences of, and travel behavior before and after, relocating. A grounded theory approach was taken to analysis. Results Twenty-six commuters participated. Participants were motivated by convenience, speed, cost and reliability when selecting modes of travel for commuting. Physical activity was not a primary motivation, but incidental increases in physical activity were described and valued in association with active commuting, the use of public transport and the use of park-and-ride facilities. Conclusions Emphasizing and improving the relative convenience, cost, speed and reliability of active commuting may be a more promising approach to promoting its uptake than emphasizing the health benefits, at least around the time of relocation. Providing good quality public transport and free car parking within walking or cycling distance of major employment sites may encourage the inclusion of active travel in the journey to work

  18. Particulates and noise exposure during bicycle, bus and car commuting: A study in three European cities.

    Science.gov (United States)

    Okokon, Enembe O; Yli-Tuomi, Tarja; Turunen, Anu W; Taimisto, Pekka; Pennanen, Arto; Vouitsis, Ilias; Samaras, Zissis; Voogt, Marita; Keuken, Menno; Lanki, Timo

    2017-04-01

    In order to curb traffic-related air pollution and its impact on the physical environment, contemporary city commuters are encouraged to shift from private car use to active or public transport modes. However, personal exposures to particulate matter (PM), black carbon and noise during commuting may be substantial. Therefore, studies comparing exposures during recommended modes of transport versus car trips are needed. We measured personal exposure to various-sized particulates, soot, and noise during commuting by bicycle, bus and car in three European cities: Helsinki in Finland, Rotterdam in the Netherlands and Thessaloniki in Greece using portable monitoring devices. We monitored commonly travelled routes in these cities. The total number of one-way trips yielding data on any of the measured parameters were 84, 72, 94 and 69 for bicycle, bus, closed-window car and open-window car modes, respectively. The highest mean PM 2.5 (85µg/m 3 ), PM 10 (131µg/m 3 ), black carbon (10.9µg/m 3 ) and noise (75dBA) levels were recorded on the bus, bus (again), open-window car and bicycle modes, respectively, all in Thessaloniki, PM and soot concentrations were generally higher during biking and taking a bus than during a drive in a a car with closed windows. Ratios of bike:car PM 10 ranged from 1.1 in Thessaloniki to 2.6 in Helsinki, while bus:car ratios ranged from in 1.0 in Rotterdam to 5.6 in Thessaloniki. Higher noise levels were mostly recorded during bicycle rides. Based on our study, active- and public-transport commuters are often at risk of higher air pollution and noise exposure than private car users. This should be taken into account in urban transportation planning. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Non-commutative covering spaces and their symmetries

    DEFF Research Database (Denmark)

    Canlubo, Clarisson

    -commutative covering space using Galois theory of Hopfalgebroids. We will look at basic properties of classical covering spaces that generalize to thenon-commutative framework. Afterwards, we will explore a series of examples. We will startwith coverings of a point and central coverings of commutative spaces and see...... how these areclosely tied up. Coupled Hopf algebras will be presented to give a general description of coveringsof a point. We will give a complete description of the geometry of the central coverings ofcommutative spaces using the coverings of a point. A topologized version of Hopf categories willbe...... the non-commutative analogue of the hyperelliptic involution, we will showthat unlike the classical case, the non-commutative sphere is a covering of the non-commutativetorus. There is a purely non-commutative phenomenon happening to non-commutative coverings,namely, their symmetry is two-sided. We...

  20. Solar-to-vehicle (S2V) systems for powering commuters of the future

    Science.gov (United States)

    Birnie, Dunbar P.

    Hybrid electric vehicles are growing in popularity and significance in our marketplace as gasoline prices continue to rise. Consumers are also increasingly aware of their carbon "footprint" and seek ways of lowering their carbon dioxide output. Plug-in hybrid and electric vehicles appear to be the next wave in helping transition from a gasoline-based transportation infrastructure to an electric-grid-sourced mode, though most plug-in scenarios ultimately rely on having the electric utilities converted from fossil sources to renewable generation in the long run. At present, one of the key advantages of plug-in hybrid/electric vehicles is that they can be charged at home, at night, when lower off-peak rates could apply. The present analysis considers a further advancement: the impact of daytime recharging using solar arrays located at commuters' work sites. This would convert large parking areas into solar recharge stations for commuters. The solar power would be large enough to supply many commuters' needs. The implications for electric car design in relation to commuter range are discussed in detail.

  1. A survey of ophthalmologists and gynecologists regarding termination of pregnancy and choice of delivery mode in the presence of eye diseases.

    Science.gov (United States)

    Mohammadi, Seyed-Farzad; Letafat-Nejad, Mojgan; Ashrafi, Elham; Delshad-Aghdam, Hanieh

    2017-06-01

    To evaluate and compare the attitudes of ophthalmologists and gynecologists in suggesting appropriate approach to pregnancy in different ocular conditions. Specialty-specific questionnaires on delivery mode and abortion indications for ophthalmic patients (refractive, vascular, oncologic, retinal, glaucoma, postoperation, posttrauma, and infectious) were designed and distributed among physician staff of Farabi Eye Hospital and Yas Women Hospital in Tehran. Attitudes and preferences of the ophthalmologists and gynecologists were quantified and compared. Participants were 29 ophthalmologists and 19 gynecologists. Their mean age was 49.73 ± 7.57 and 46.79 ± 1.36 years, respectively. More than 50-70% ophthalmologists were in favor of normal vaginal delivery (NVD) in all ocular diseases. All gynecologists (100%) expressed their need for an ophthalmologist's opinion for decision-making. Ophthalmologists' top choices for conditions potentially requiring a caesarean section were corneal transplants (34.5%), high myopia (23%), retinal detachment (29%), and orbital tumors (34.5%), while two gynecologists recommended abortion in the presence of intraocular and orbital tumors and retinal detachment. In the case of a history of refractive surgery, orbital tumor and intraocular tumor, ophthalmologists recommend NVD over caesarean section twice as much as their gynecologist peers. For history of retinal detachment, glaucoma, retinal vascular accident and intraocular hemorrhage, no single gynecologist recommend NVD. The corresponding figure for ophthalmologist-recommended NVD were 67, 84, 72, and 81%. There is extreme inconsistency among ophthalmologists and gynecologists in managing ophthalmic-obstetric scenarios, especially for caesarean section indications. Clinical guideline development and consultation for decision-making in challenging cases are recommended.

  2. Neighborhood educational disparities in active commuting among women: the effect of distance between the place of residence and the place of work/study (an ACTI-Cités study).

    Science.gov (United States)

    Perchoux, Camille; Nazare, Julie-Anne; Benmarhnia, Tarik; Salze, Paul; Feuillet, Thierry; Hercberg, Serge; Hess, Franck; Menai, Mehdi; Weber, Christiane; Charreire, Hélène; Enaux, Christophe; Oppert, Jean-Michel; Simon, Chantal

    2017-06-12

    Active transportation has been associated with favorable health outcomes. Previous research highlighted the influence of neighborhood educational level on active transportation. However, little is known regarding the effect of commuting distance on social disparities in active commuting. In this regard, women have been poorly studied. The objective of this paper was to evaluate the relationship between neighborhood educational level and active commuting, and to assess whether the commuting distance modifies this relationship in adult women. This cross-sectional study is based on a subsample of women from the Nutrinet-Santé web-cohort (N = 1169). Binomial, log-binomial and negative binomial regressions were used to assess the associations between neighborhood education level and (i) the likelihood of reporting any active commuting time, and (ii) the share of commuting time made by active transportation modes. Potential effect measure modification of distance to work on the previous associations was assessed both on the additive and the multiplicative scales. Neighborhood education level was positively associated with the probability of reporting any active commuting time (relative risk = 1.774; p work for both outcomes. Our results suggest that neighborhood educational disparities in active commuting tend to increase with commuting distance among women. Further research is needed to provide geographically driven guidance for health promotion intervention aiming at reducing disparities in active transportation among socioeconomic groups.

  3. Expanded commuting in the metropolitan region of Belo Horizonte: evidence for reverse commuting

    Directory of Open Access Journals (Sweden)

    Carlos Lobo

    2015-08-01

    Full Text Available AbstractLarge Brazilian cities, particularly those that have experienced rapid population growth since the middle of the last century, have exhibited significant signs of population dispersion in their peripheries in recent decades. A study of the population’s spatial redistribution in the Metropolitan Region of Belo Horizonte (MRBH confirms this finding. In the process of dispersion, the levels of urban commuting increase, and commuting becomes a relevant indicator of the degree of integration within the metropolis. This paper evaluates the current magnitude and main features of reverse commuting, as characterized by the daily displacements of the population that resides not in the periphery but rather in the core. Flows from the metropolitan core towards the peripheral municipalities are examined using sample microdata on the MRBH municipalities from the 2000 and 2010 demographic censuses by combining the variables of "municipality of residence" and "municipality of work/study." The results indicate an increase in reverse commuting in both absolute and relative terms. When this flow is compared totraditional commuting (periphery/center, the relative values are considerable. In some cases, this relationship reaches notably high values, as the case of Confins (the municipality where the international airport is located, and also municipalities that are part of a relatively old conurbation, such as Nova Lima and Betim.

  4. Eulerian Dynamics with a Commutator Forcing

    Science.gov (United States)

    2017-01-09

    EULERIAN DYNAMICS WITH A COMMUTATOR FORCING ROMAN SHVYDKOY AND EITAN TADMOR Abstract. We study a general class of Euler equations driven by a forcing...visit which initiated this work. Finally we thank the Institute for Theoretical Studies (ITS) at ETH-Zurich for the hospitality. 1 2 ROMAN SHVYDKOY AND...well. 4 ROMAN SHVYDKOY AND EITAN TADMOR Theorem 1.1. Consider the hydrodynamics flocking model (1.10) with a bounded mollifier, φ ∈ L∞# having a

  5. Sensorless Commutation Control of Switched Reluctance Motor

    OpenAIRE

    N.H. Mvungi

    2007-01-01

    This paper addresses control of commutation of switched reluctance (SR) motor without the use of a physical position detector. Rotor position detection schemes for SR motor based on magnetisation characteristics of the motor use normal excitation or applied current /voltage pulses. The resulting schemes are referred to as passive or active methods respectively. The research effort is in realizing an economical sensorless SR rotor position detector that is accurate, reliable and robust to suit...

  6. Attitudes, social support and environmental perceptions as predictors of active commuting behaviour in school children.

    Science.gov (United States)

    Panter, J R; Jones, A P; van Sluijs, E M F; Griffin, S J

    2010-01-01

    Environmental perceptions appear to play a role in determining behaviour in children, although their influence on active commuting remains unclear. This study examines whether attitudes, social support and environmental perceptions are associated with active commuting behaviour in school children and whether these associations are moderated by the distance to school. Data were collected as part of the SPEEDY study (Sport, Physical activity and Eating behaviour: Environmental Determinants in Young people), a cross-sectional study of 2064 children from schools in Norfolk, UK. Data regarding the usual mode of travel to school, attitudes towards and social support for active commuting, perceptions of the neighbourhood and route to school were assessed using questionnaires completed by 2012 children and their parents. Distance to school was estimated using a Geographic Information System and this was used to compare associations between personal and environmental factors and active travel, across different distance categories. Forty per cent of children reported usually walking to school, with 9% cycling and the remainder using motorised travel. Parental attitudes and safety concerns, the presence of social support from parents and friends and parent-reported neighbourhood walkability were all found to be predictors of active commuting, with children receiving peer and family support and living in supportive environments being more likely to walk or cycle. There was some evidence of a moderating effect of distance whereby attitudes were more important for short distances and safety concerns long. Both attitudinal and environmental perceptions are associated with children's active commuting behaviours. Given the difficulty in modifying attitudes directly, the effect on them of interventions to provide more supportive environments should be evaluated.

  7. The influence of response mode on study results: offering cigarette smokers a choice of postal or online completion of a survey.

    Science.gov (United States)

    Callas, Peter W; Solomon, Laura J; Hughes, John R; Livingston, Amy E

    2010-10-21

    It is unclear whether offering online data collection to study participants affects compliance or produces bias. To compare response rates, baseline characteristics, test-retest reliability, and outcomes between cigarette smokers who chose to complete a survey by mail versus those who chose to complete it online. We surveyed cigarette smokers who intended to stop smoking within the next 30 days to determine barriers to calling a smoking quit line. Participants were offered the choice of completing a paper version of the survey sent through the mail or an online version at a password-protected website. Participants were called 2 months later to determine if they had made a quit attempt and/or called a smoking quit line since the baseline survey. We compared characteristics and outcomes among those who chose postal versus online completion. We measured test-retest reliability of the baseline survey by re-surveying a semi-random sample of participants within 10 days of the original survey. Of 697 eligible respondents to newspaper ads in 12 US cities, 438 (63%) chose to receive a mailed paper survey and 259 (37%) chose an Internet survey. Survey return rates were the same for the 2 modes (92% versus 92%, P = .82). Online respondents were younger (mean of 46 versus 51 years old for postal, P online versus 55% for postal, P = .72) or cigarettes smoked per day (mean of 19 versus 21, P = .30). Online respondents had slightly fewer missing items on the 79-item survey (mean of 1.7% missing versus 2.3%, P = .02). Loss to follow-up at 2 months was similar (16% for online and 15% for postal, P = .74). There was no significant difference between online and postal respondents in having called a smoking quit line during the 2-month follow-up period (20% versus 24%, P = .22) or in having made a quit attempt (76% versus 79%, P = .41). Cigarette smokers who chose to complete a survey using the Internet differed in several ways from those who chose mailed surveys. However, more

  8. Characteristics of a population of commuter cyclists in the Netherlands: perceived barriers and facilitators in the personal, social and physical environment

    Directory of Open Access Journals (Sweden)

    Hendriksen Ingrid JM

    2010-12-01

    Full Text Available Abstract Background Daily cycling to work has been shown to improve physical performance and health in men and women. It is very common in the Netherlands: the most recent data show that one quarter of commuting journeys are by bicycle. However, despite the effort going into campaigns to promote commuter cycling, about 30% of commuter journeys up to 5 kilometers are still by car. The question is how to stimulate commuter cycling more effectively. This article aims to contribute to a better understanding of the perceived barriers and facilitators of cyclists/non-cyclists and personal factors associated with commuter cycling. Methods A random sample of 799 Dutch employees (response rate 39.6% completed an internet survey, which comprised two parts. One part of the questionnaire focused on the determinants of cycling behavior including equal numbers of personal, social factors and environmental factors. The other component focused on assessing data on physical activity (PA behavior. Descriptive and logistic regression analyses were used to analyze factors associated with commuter cycling. Results Meeting the physical activity guideline was positively associated with commuter cycling. Television viewing and working full-time were negatively associated. Twenty-six percent of the participants met the PA guideline simply by cycling to work, with health as the main reason. The main barriers for non-cyclists (60% were perspiration when arriving at work, weather and travelling time. Shorter travelling times compared with other transportation modes were an important facilitator. Environmental factors were positively related to more frequent and more convenient commuter cycling, but they were hardly mentioned by non-cyclists. Conclusions This study shows that a relatively large group fulfils the PA recommendations merely by cycling to work. Personal factors (i.e., perceived time and distance are major barriers to commuter cycling and should be targeted in

  9. The effect of sprawl on private-vehicle commuting outcomes

    OpenAIRE

    Edmund J Zolnik

    2011-01-01

    Amongst the hypothesized beneficial impacts of sprawl on urban quality of life is a decrease in commuting times. Unfortunately, empirical evidence to substantiate the commuting time benefits of sprawl is scant. To address this void in the urban planning literature, a multilevel approach is adopted to study how sprawl affects the duration and length of private-vehicle commutes. Using microdata from the 2001 National Household Transportation Survey for individuals and microdata on various measu...

  10. On the Commutativity of a Certain Class of Toeplitz Operators

    Directory of Open Access Journals (Sweden)

    Louhichi Issam

    2014-01-01

    Full Text Available One of the major goals in the theory of Toeplitz operators on the Bergman space over the unit disk D in the complex place C is to completely describe the commutant of a given Toeplitz operator, that is, the set of all Toeplitz operators that commute with it. Here we shall study the commutants of a certain class of quasihomogeneous Toeplitz operators defined on the harmonic Bergman space.

  11. On a weighted Toeplitz operator and its commutant

    Directory of Open Access Journals (Sweden)

    Vasile Lauric

    2005-05-01

    Full Text Available We study the structure of a class of weighted Toeplitz operators and obtain a description of the commutant of each operator in this class. We make some progress towards proving that the only operator in the commutant which is not a scalar multiple of the identity operator and which commutes with a nonzero compact operator is zero. The proof of the main statement relies on a conjecture which is left as an open problem.

  12. Self-commutating converters for high power applications

    CERN Document Server

    Arrillaga, Jos; Watson, Neville R; Murray, Nicholas J

    2010-01-01

    For very high voltage or very high current applications, the power industry still relies on thyristor-based Line Commutated Conversion (LCC), which limits the power controllability to two quadrant operation. However, the ratings of self-commutating switches such as the Insulated-Gate Bipolar Transistor (IGBT) and Integrated Gate-Commutated Thyristor (IGCT), are reaching levels that make the technology possible for very high power applications. This unique book reviews the present state and future prospects of self-commutating static power converters for applications requiring either ultr

  13. Exploring characteristics and motives of long distance commuter cyclists

    DEFF Research Database (Denmark)

    Hansen, Karsten Bruun; Nielsen, Thomas Alexander Sick

    2014-01-01

    , commuter cyclists (>5 km from home to work) have more mobility options, higher incomes, and a longer education than other commuter cyclists. The main motive for longer distance cycling is physical exercise, followed by reduced costs and time used for traveling. The long distance commuter cyclists surveyed...... are very positive about their commute - pointing to positive experiences, better mood, and stress relief as experiences related to their cycle trip to work. Policy support should devote attention to unlocking the potential that may be embedded in individuals combining their exercise and travel time...

  14. Theory of generalized inverses over commutative rings

    CERN Document Server

    Bhaskara Rao, KPS

    2003-01-01

    The theory of generalized inverses of real or complex matrices has been expertly developed and documented. But the generalized inverses of matrices over rings have received comprehensive treatment only recently. In this book, the author, who contributed to the research and development of the theory, explains his results. He explores regular elements in a ring, regular matrices over principal ideal rings, and regular matrices over commutative rings. Students, mathematicians working in g-inverses of matrices, along with algebraists, and control theorists will find new and indispensable data, presented with clarity and insight. This book is also well suited to graduate courses on g-inverses in algebra.

  15. Personal and environmental characteristics associated with choice of active transport modes versus car use for different trip purposes of trips up to 7.5 kilometers in The Netherlands.

    Directory of Open Access Journals (Sweden)

    Eline Scheepers

    Full Text Available INTRODUCTION: This explorative study examines personal and neighbourhood characteristics associated with short-distance trips made by car, bicycle or walking in order to identify target groups for future interventions. METHODS: Data were derived from 'Mobility Research Netherlands (2004-2009; MON', a dataset including information regarding trips made by household members (n = ±53,000 respondents annually. Using postal codes of household addresses, MON data were enriched with data on neighbourhood typologies. Multilevel logistic modelling was used to calculate odds ratio (OR of active transport versus car use associated with four different trip purposes (shopping (reference, commuting, taking or bringing persons or sports. A total of 277,292 short distance trips made by 102,885 persons were included in analyses. RESULTS: Compared to women shopping, women less often take active transport to sports clubs (OR = 0.88 and men less often take active transport for shopping (OR = 0.92, or for bringing or taking persons (OR = 0.76. Those aged 25-34 years (OR = 0.83 and 35-44 years (OR = 0.96 were more likely to use active transport for taking or bringing persons than persons belonging to the other age groups (relative to trips made for shopping by those 65 years or over. A higher use of active transport modes by persons with an university or college degree was found and particularly persons living in urban-centre neighbourhoods were likely to use active transport modes. CONCLUSION: IN DEVELOPING POLICIES PROMOTING A MODE SHIFT SPECIAL ATTENTION SHOULD BE GIVEN TO THE FOLLOWING GROUPS: a men making short distance trips for taking or bringing persons, b women making short distance trips to sport facilities, c persons belonging to the age groups of 25-44 years of age, d Persons with a primary school or lower general secondary education degree and persons with a high school or secondary school degree and e persons living in rural or

  16. Personal and environmental characteristics associated with choice of active transport modes versus car use for different trip purposes of trips up to 7.5 kilometers in The Netherlands.

    Science.gov (United States)

    Scheepers, Eline; Wendel-Vos, Wanda; van Kempen, Elise; Panis, Luc Int; Maas, Jolanda; Stipdonk, Henk; Moerman, Menno; den Hertog, Frank; Staatsen, Brigit; van Wesemael, Pieter; Schuit, Jantine

    2013-01-01

    This explorative study examines personal and neighbourhood characteristics associated with short-distance trips made by car, bicycle or walking in order to identify target groups for future interventions. Data were derived from 'Mobility Research Netherlands (2004-2009; MON)', a dataset including information regarding trips made by household members (n = ±53,000 respondents annually). Using postal codes of household addresses, MON data were enriched with data on neighbourhood typologies. Multilevel logistic modelling was used to calculate odds ratio (OR) of active transport versus car use associated with four different trip purposes (shopping (reference), commuting, taking or bringing persons or sports). A total of 277,292 short distance trips made by 102,885 persons were included in analyses. Compared to women shopping, women less often take active transport to sports clubs (OR = 0.88) and men less often take active transport for shopping (OR = 0.92), or for bringing or taking persons (OR = 0.76). Those aged 25-34 years (OR = 0.83) and 35-44 years (OR = 0.96) were more likely to use active transport for taking or bringing persons than persons belonging to the other age groups (relative to trips made for shopping by those 65 years or over). A higher use of active transport modes by persons with an university or college degree was found and particularly persons living in urban-centre neighbourhoods were likely to use active transport modes. IN DEVELOPING POLICIES PROMOTING A MODE SHIFT SPECIAL ATTENTION SHOULD BE GIVEN TO THE FOLLOWING GROUPS: a) men making short distance trips for taking or bringing persons, b) women making short distance trips to sport facilities, c) persons belonging to the age groups of 25-44 years of age, d) Persons with a primary school or lower general secondary education degree and persons with a high school or secondary school degree and e) persons living in rural or urban-green neighbourhoods.

  17. Noise exposure during commuting in three European cities

    NARCIS (Netherlands)

    Taimisto, P.; Yli-Tuomi, T.; Pennanen, A.; Vouitsis, I.; Samaras, Z.; Keuken, M.P.; Lanki, T.

    2013-01-01

    In the TRANSPHORM study, noise exposures during commuting were measured. Measurements were performed with noise dosimeters in three European cities, Helsinki, Thessaloniki and Rotterdam, during spring 2011. ln each city, two to five approximately 8 km commuting routes were selected to represent

  18. Soft commutated direct current motor [summary of proposed paper

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, John S.

    1998-10-22

    A novel soft commutated direct current (DC) motor is introduced. The current of the commutated coil is intentionally drained before the brush disconnects the coil. This prevents the spark generation that normally occurs in conventional DC motors. A similar principle can be applied for DC generators.

  19. An improved 4-step commutation method application for matrix converter

    DEFF Research Database (Denmark)

    Guo, Yu; Guo, Yougui; Deng, Wenlang

    2014-01-01

    A novel four-step commutation method is proposed for matrix converter cell, 3 phase inputs to 1 phase output in this paper, which is obtained on the analysis of published commutation methods for matrix converter. The first and fourth step can be shorter than the second or third one. The discussed...

  20. a generalization of zero divisor graphs associated to commutative ...

    Indian Academy of Sciences (India)

    8

    zero divisor graph of R. In this paper, we study some basic properties of Γn. R. We also determine all isomorphic classes of finite commutative rings whose generalized zero divisor graphs have genus at most three. 1. Introduction. Let R be a commutative ring with a nonzero identity element, and let Z(R) be the set of all zero ...

  1. 26 CFR 1.46-11 - Commuter highway vehicles.

    Science.gov (United States)

    2010-04-01

    ... Rules for Computing Credit for Investment in Certain Depreciable Property § 1.46-11 Commuter highway... investment under section 46(c)(1) for a qualifying commuter highway vehicle is 100 percent. A qualifying... meets the following requirements: (1) The vehicle is section 38 property in the hands of the taxpayer...

  2. Commutators with idempotent values on multilinear polynomials in ...

    Indian Academy of Sciences (India)

    Introduction and statements of the result. In mid-forties, after the development of the general structure theory for rings, a great deal of work was done that showed that under certain types of hypothesis, rings had to be commutative or almost commutative. A classical result of ring theory established by Jacobson generalizes at ...

  3. Geometry, commutation relations and the quantum fictitious force

    DEFF Research Database (Denmark)

    Botero, J.; Cirone, M.A.; Dahl, Jens Peder

    2003-01-01

    We express the commutation relation between the operators of the momentum and the radial unit vectors in D dimensions in differential and integral form. We connect this commutator with the quantum fictitious potential emerging in the radial Schrodinger equation of an s-wave....

  4. Non-commutative relativistic equation with a Coulomb potential

    Energy Technology Data Exchange (ETDEWEB)

    Zaim, Slimane; Khodja, Lamine; Delenda, Yazid [Departement de Physique, Faculte des Sciences, Universite Hadj Lakhdar - Batna (Algeria); Departement de Physique, Faculte des Sciences Exactes, Universite de Bejaia (Algeria); Departement de Physique, Faculte des Sciences, Universite Hadj Lakhdar - Batna (Algeria)

    2012-06-27

    We improve the previous study of the Klein-Gordon equation in a non-commutative space-time as applied to the Hydrogen atom to extract the energy levels, by considering the secondorder corrections in the non-commutativity parameter. Phenomenologically we show that noncommutativity plays the role of spin.

  5. Homogeneous Buchberger algorithms and Sullivant's computational commutative algebra challenge

    DEFF Research Database (Denmark)

    Lauritzen, Niels

    2005-01-01

    We give a variant of the homogeneous Buchberger algorithm for positively graded lattice ideals. Using this algorithm we solve the Sullivant computational commutative algebra challenge.......We give a variant of the homogeneous Buchberger algorithm for positively graded lattice ideals. Using this algorithm we solve the Sullivant computational commutative algebra challenge....

  6. Reducing employee travelling time through smart commuting

    Science.gov (United States)

    Rahman, A. N. N. A.; Yusoff, Z. M.; Aziz, I. S.; Omar, D.

    2014-02-01

    Extremely congested roads will definitely delay the arrival time of each trip.This certainly impacted the journey of employees. Tardiness at the workplace has become a perturbing issue for companies where traffic jams are the most common worker excuses. A depressing consequence on daily life and productivity of the employee occurs. The issues of commuting distance between workplace and resident area become the core point of this research. This research will emphasize the use of Geographical Information System (GIS) technique to explore the distance parameter to the employment area and will focus on the accessibility pattern of low-cost housing. The research methodology consists of interview sessions and a questionnaire to residents of low-cost housing areas in Melaka Tengah District in Malaysia. The combination of these processes will show the criteria from the selected parameter for each respondent from their resident area to the employment area. This will further help in the recommendation of several options for a better commute or improvement to the existing routes and public transportations system. Thus enhancing quality of life for employees and helping to reduce stress, decrease lateness, absenteeism and improving productivity in workplace.

  7. Shock Waves and Commutation Speed of Memristors

    Science.gov (United States)

    Tang, Shao; Tesler, Federico; Marlasca, Fernando Gomez; Levy, Pablo; Dobrosavljević, V.; Rozenberg, Marcelo

    2016-01-01

    Progress of silicon-based technology is nearing its physical limit, as the minimum feature size of components is reaching a mere 10 nm. The resistive switching behavior of transition metal oxides and the associated memristor device is emerging as a competitive technology for next-generation electronics. Significant progress has already been made in the past decade, and devices are beginning to hit the market; however, this progress has mainly been the result of empirical trial and error. Hence, gaining theoretical insight is of the essence. In the present work, we report the striking result of a connection between the resistive switching and shock-wave formation, a classic topic of nonlinear dynamics. We argue that the profile of oxygen vacancies that migrate during the commutation forms a shock wave that propagates through a highly resistive region of the device. We validate the scenario by means of model simulations and experiments in a manganese-oxide-based memristor device, and we extend our theory to the case of binary oxides. The shock-wave scenario brings unprecedented physical insight and enables us to rationalize the process of oxygen-vacancy-driven resistive change with direct implications for a key technological aspect—the commutation speed.

  8. Associations between Active Commuting to School and Health-Related Physical Fitness in Spanish School-Aged Children: A Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Emilio Villa-González

    2015-08-01

    Full Text Available Active commuting (walking or cycling to school has been positively associated with improved fitness among adolescents. However, current evidence lacks information on whether this association persists in children. The aim of this study was to examine the association of active commuting to school with different fitness parameters in Spanish school-aged children. A total of 494 children (229 girls from five primary schools in Granada and Jaén (Spain, aged between eight and 11 years, participated in this cross-sectional study. Participants completed the Assessing Levels of Physical Activity (ALPHA fitness test battery and answered a self-reported questionnaire regarding the weekly travel mode to school. Active commuting to school was significantly associated with higher levels of speed-agility in boys (p = 0.048 and muscle strength of the lower body muscular fitness in girls (p = 0.016. However, there were no significant associations between active commuting to school and cardiorespiratory fitness and upper body muscular fitness. Our findings suggest that active commuting to school was associated with higher levels of both speed-agility and lower body muscular fitness in boys and girls, respectively. Future studies should confirm whether increasing active commuting to school increases speed-agility and muscle strength of the lower body.

  9. Associations between Active Commuting to School and Health-Related Physical Fitness in Spanish School-Aged Children: A Cross-Sectional Study.

    Science.gov (United States)

    Villa-González, Emilio; Ruiz, Jonatan R; Chillón, Palma

    2015-08-26

    Active commuting (walking or cycling) to school has been positively associated with improved fitness among adolescents. However, current evidence lacks information on whether this association persists in children. The aim of this study was to examine the association of active commuting to school with different fitness parameters in Spanish school-aged children. A total of 494 children (229 girls) from five primary schools in Granada and Jaén (Spain), aged between eight and 11 years, participated in this cross-sectional study. Participants completed the Assessing Levels of Physical Activity (ALPHA) fitness test battery and answered a self-reported questionnaire regarding the weekly travel mode to school. Active commuting to school was significantly associated with higher levels of speed-agility in boys (p = 0.048) and muscle strength of the lower body muscular fitness in girls (p = 0.016). However, there were no significant associations between active commuting to school and cardiorespiratory fitness and upper body muscular fitness. Our findings suggest that active commuting to school was associated with higher levels of both speed-agility and lower body muscular fitness in boys and girls, respectively. Future studies should confirm whether increasing active commuting to school increases speed-agility and muscle strength of the lower body.

  10. Euler polynomials and identities for non-commutative operators

    Science.gov (United States)

    De Angelis, Valerio; Vignat, Christophe

    2015-12-01

    Three kinds of identities involving non-commutating operators and Euler and Bernoulli polynomials are studied. The first identity, as given by Bender and Bettencourt [Phys. Rev. D 54(12), 7710-7723 (1996)], expresses the nested commutator of the Hamiltonian and momentum operators as the commutator of the momentum and the shifted Euler polynomial of the Hamiltonian. The second one, by Pain [J. Phys. A: Math. Theor. 46, 035304 (2013)], links the commutators and anti-commutators of the monomials of the position and momentum operators. The third appears in a work by Figuieira de Morisson and Fring [J. Phys. A: Math. Gen. 39, 9269 (2006)] in the context of non-Hermitian Hamiltonian systems. In each case, we provide several proofs and extensions of these identities that highlight the role of Euler and Bernoulli polynomials.

  11. Socioeconomic, Personal and Behavioral Correlates of Active Commuting among Adolescents

    Directory of Open Access Journals (Sweden)

    Adilson Marques

    2016-03-01

    Full Text Available The aims of this study were to assess the relationships between commuting to and from school (active vs. passive and their explanatory variables. A total of 2653 adolescents (1361 boys, 1292 girls; M age=13.4±2.6 participated in this study. The students were questioned about commuting to and from school, physical activity and school sports participation and perceptions of competence and health. Socioeconomic status and body mass index were calculated. Results show that a minority of the students use active transportation to and from school. Also, age increasing, participation in school sports and increasing duration were positively correlated with active commuting for both routes (to and from school. Given that active commuting may be a simple and effective way to increase physical activity level among youth populations, it is important to promote, improve conditions and create strategies in order to increase the number of students that actively commute to and from school.

  12. Offshoring in the service sector : An empirical investigation on the offshoring behavior of service firms and its influence on their foreign entry mode choice

    NARCIS (Netherlands)

    Gorp, van D.M.

    2010-01-01

    This study is focused on the offshoring behavior of service firms. It provides a decision-making model for service firms regarding their choice for captive offshoring or offshore outsourcing when relocating their activities to foreign locations. Service firms are taken as the focus of this study

  13. Active Commuting among K-12 Educators: A Study Examining Walking and Biking to Work

    Directory of Open Access Journals (Sweden)

    Melissa Bopp

    2013-01-01

    Full Text Available Background. Walking and biking to work, active commuting (AC is associated with many health benefits, though rates of AC remain low in the US. K-12 educators represent a significant portion of the workforce, and employee health and associated costs may have significant economic impact. Therefore, the purpose of this study was to examine the current rates of AC and factors associated with AC among K-12 educators. Methods. A volunteer sample of K-12 educators ( was recruited to participate in an online survey. Participants responded about AC patterns and social ecological influences on AC (individual, interpersonal, institutional, community, and environmental factors. -tests and ANOVAs examined trends in AC, and Pearson correlations examined the relationship between AC and dependent variables. Multiple regression analysis determined the relative influence of individual, interpersonal, institutional, community, and environmental levels on AC. Results. Participants actively commuted times/week. There were several individual, interpersonal, institutional, community, and environmental factors significantly related to AC. The full model explained 60.8% of the variance in AC behavior. Conclusions. This study provides insight on the factors that determine K-12 educators mode of commute and provide some insight for employee wellness among this population.

  14. Investigating Spatial Interdependence in E-Bike Choice Using Spatially Autoregressive Model

    Directory of Open Access Journals (Sweden)

    Chengcheng Xu

    2017-08-01

    Full Text Available Increased attention has been given to promoting e-bike usage in recent years. However, the research gap still exists in understanding the effects of spatial interdependence on e-bike choice. This study investigated how spatial interdependence affected the e-bike choice. The Moran’s I statistic test showed that spatial interdependence exists in e-bike choice at aggregated level. Bayesian spatial autoregressive logistic analyses were then used to investigate the spatial interdependence at individual level. Separate models were developed for commuting and non-commuting trips. The factors affecting e-bike choice are different between commuting and non-commuting trips. Spatial interdependence exists at both origin and destination sides of commuting and non-commuting trips. Travellers are more likely to choose e-bikes if their neighbours at the trip origin and destination also travel by e-bikes. And the magnitude of this spatial interdependence is different across various traffic analysis zones. The results suggest that, without considering spatial interdependence, the traditional methods may have biased estimation results and make systematic forecasting errors.

  15. Neighborhood educational disparities in active commuting among women: the effect of distance between the place of residence and the place of work/study (an ACTI-Cités study

    Directory of Open Access Journals (Sweden)

    Camille Perchoux

    2017-06-01

    Full Text Available Abstract Background Active transportation has been associated with favorable health outcomes. Previous research highlighted the influence of neighborhood educational level on active transportation. However, little is known regarding the effect of commuting distance on social disparities in active commuting. In this regard, women have been poorly studied. The objective of this paper was to evaluate the relationship between neighborhood educational level and active commuting, and to assess whether the commuting distance modifies this relationship in adult women. Methods This cross-sectional study is based on a subsample of women from the Nutrinet-Santé web-cohort (N = 1169. Binomial, log-binomial and negative binomial regressions were used to assess the associations between neighborhood education level and (i the likelihood of reporting any active commuting time, and (ii the share of commuting time made by active transportation modes. Potential effect measure modification of distance to work on the previous associations was assessed both on the additive and the multiplicative scales. Results Neighborhood education level was positively associated with the probability of reporting any active commuting time (relative risk = 1.774; p < 0.05 and the share of commuting time spent active (relative risk = 1.423; p < 0.05. The impact of neighborhood education was greater at long distances to work for both outcomes. Conclusions Our results suggest that neighborhood educational disparities in active commuting tend to increase with commuting distance among women. Further research is needed to provide geographically driven guidance for health promotion intervention aiming at reducing disparities in active transportation among socioeconomic groups.

  16. Commuting behavior of western U.S. residents

    Energy Technology Data Exchange (ETDEWEB)

    Caviglia, J. [Tennessee Univ., Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States)

    1996-06-01

    Estimation and interpretation of commutes to work has been studied extensively with respect to gender, race, and income. While the literature is extensive in these areas, there has been little research on regional differences between US states and territories. Since data which reports the commute to work is in average minutes, the distance traveled is estimated using estimates of the distance between home and work county centroids. The models differ in estimation of in-county commutes. The first assumes that the commute is equal to the radius of the county and the second estimates the commute as a weighted distance based on place location. Two data sets are compared, US National Guard data and US census data. Goal of this paper is to make conclusions about the commuting behavior of western residents through the use of these estimates, and therefore to provide a estimation method for distance commutes which can be used in further research. It is concluded that the radius method of estimation may be an over estimation, in particular in the western states. Since the non-western states are generally more homogeneously populated, this overestimation is not observed. It is recommended that the place location method be used for similar research, in particular studies dealing with western states. Suggestions are made for further research and recommendations are made for the US Army National Guard in regards to recruiting.

  17. Biologic and epigenetic impact of commuting to work by car or using public transportation: a case-control study.

    Science.gov (United States)

    Morabia, Alfredo; Zhang, Fang Fang; Kappil, Maya A; Flory, Janine; Mirer, Frank E; Santella, Regina M; Wolff, Mary; Markowitz, Steven B

    2012-01-01

    Commuting by public transportation (PT) entails more physical activity and energy expenditure than by cars, but its biologic consequences are unknown. In 2009-2010, we randomly sampled New York adults, usually commuting either by car (n=79) or PT (n=101). Measures comprised diet and physical activity questionnaires, weight and height, white blood cell (WBC) count, C reactive protein, (CRP) gene-specific methylation (IL-6), and global genomic DNA methylation (LINE-1 methylation). Compared to the 101 PT commuters, the 79 car drivers were about 9 years older, 2 kg/m(2) heavier, more often non-Hispanic whites, and ate more fruits and more meats. The 2005 guidelines for physical activity were met by more car drivers than PT users (78.5% vs. 65.0%). There were no differences in median levels of CRP (car vs. PT: 0.6 vs. 0.5mg/dl), mean levels of WBC (car vs. PT: 6.7 vs. 6.5 cells/mm(3)), LINE-1 methylation (car vs. PT: 78.0% vs. 78.3%), and promoter methylation of IL-6 (car vs. PT: 56.1% vs. 58.0%). PT users were younger and lighter than car drivers, but their commute mode did not translate into a lower inflammatory response or a higher DNA methylation, maybe because, overall, car drivers were more physically active. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Modelling the relation between income and commuting distance

    DEFF Research Database (Denmark)

    Carra, Giulia; Mulalic, Ismir; Fosgerau, Mogens

    2016-01-01

    We discuss the distribution of commuting distances and its relation to income. Using data from Denmark, the UK and the USA, we show that the commuting distance is (i) broadly distributed with a slow decaying tail that can be fitted by a power law with exponent γ ≈ 3 and (ii) an average growing...... of the worker and decreases with the wage. The predicted distribution of commuting distances decays as 1/r3 and is independent of the distribution of the quality of jobs. We find our alternative model to be in agreement with our data. This type of approach opens new perspectives for the modelling of mobility....

  19. Mechanism For Adjustment Of Commutation Of Brushless Motor

    Science.gov (United States)

    Schaefer, Richard E.

    1995-01-01

    Mechanism enables adjustment of angular position of set of Hall-effect devices that sense instantaneous shaft angle of brushless dc motor. Outputs of sensors fed to commutation circuitry. Measurement of shaft angle essential for commutation; that is, application of voltage to stator windings must be synchronized with shaft angle. To obtain correct angle measurement for commutation, Hall-effect angle sensors positioned at proper reference angle. The present mechanism accelerates adjustment procedure and makes it possible to obtain more accurate indication of minimum-current position because it provides for adjustment while motor running.

  20. A remark on generalized commutation relation and subnormality

    Directory of Open Access Journals (Sweden)

    Jerzy Bartłomiej Stochel

    2006-01-01

    Full Text Available Tillmann [Tillmann H. G., Zur Eindeutigkeit der Losungen der quanten mechanischen vertauschungrelationen, Acta Sci. Math. (Szeged 24 (1963, 258-270] proved that every operator \\(A\\ which fulfils the canonical commutation relation \\(A^{*}A - AA^{*} = Id\\ is an orthogonal sum of canonical creation operators. We extend this result for operators which fulfil generalized commutation relation \\[A^{*}A - AA^{*}= E^2,\\text{ where }EA = AE.\\] In addition, some inequalities which are helpful in describing analytic vectors of operators \\(A^{*}A\\, where \\(A\\ fulfils the generalized commutation relation, are established.

  1. Non-Commutative Mechanics in Mathematical & in Condensed Matter Physics

    Directory of Open Access Journals (Sweden)

    Peter A. Horváthy

    2006-12-01

    Full Text Available Non-commutative structures were introduced, independently and around the same time, in mathematical and in condensed matter physics (see Table 1. Souriau's construction applied to the two-parameter central extension of the planar Galilei group leads to the ''exotic'' particle, which has non-commuting position coordinates. A Berry-phase argument applied to the Bloch electron yields in turn a semiclassical model that has been used to explain the anomalous/spin/optical Hall effects. The non-commutative parameter is momentum-dependent in this case, and can take the form of a monopole in momentum space.

  2. Study of three-phase, high-frequency modulated, soft commutated inverters. Etude d'onduleurs triphases a haute frequences et a commutation douce

    Energy Technology Data Exchange (ETDEWEB)

    Cheriti, A.

    1993-05-01

    After selecting a configuration for a resonant inverter which would not generate any overvoltage on the power semiconductors and which could operate in pulse width modulation at high frequency, a pulse width modulation resonant pole inverter was studied using the state-plane technique. This technique simplifies the study of second order systems with low damping factors. The state plane is used while determining the operating sequences and their duration, the voltage and current stresses on the power semiconductors, and the operating limits. Experimental tests were conducted on a three-phase asynchronous machine based variable-speed drive controlled under the V/F constant law. The control circuit implementing this law was developed with the help of original digital circuits designed and described in the study. It is shown that the proposed inverter configuration contributes substantially to reduction in electromagnetic interference, commutation losses, and power switching stresses. To avoid any efficiency losses brought about by these improvements, importance should be placed in the different design phases of the inverter. Particular attention must be paid to the choice of the type of power switch, the calculation of the values of the reactive elements, and determination of the commutation frequency. 54 refs., 75 figs., 2 tabs.

  3. 41 CFR 102-117.220 - What choices do I have to ship HHG?

    Science.gov (United States)

    2010-07-01

    ...-TRANSPORTATION MANAGEMENT Shipping Household Goods § 102-117.220 What choices do I have to ship HHG? (a) You may choose to ship HHG by: (1) Using the commuted rate system; (2) GSA's Centralized Household Goods Traffic... Government will incur a savings ($100 or more) using another choice listed. The use of household goods rate...

  4. Active commuting and perceptions of the route environment: A longitudinal analysis

    OpenAIRE

    Panter, Jenna; Griffin, Simon; Ogilvie, David

    2014-01-01

    Objective To assess associations between changes in perceptions of the environment en route to work and changes in active commuting. Methods 655 commuters in Cambridge, UK reported perceptions of their commuting route and past-week commuting trips in postal questionnaires in 2009 and 2010. Associations between changes in route perceptions and changes in time spent walking and cycling, proportion of car trips, and switching to or from the car on the commute were modelled using multivariable re...

  5. Commutative algebra with a view toward algebraic geometry

    CERN Document Server

    Eisenbud, David

    1995-01-01

    Commutative Algebra is best understood with knowledge of the geometric ideas that have played a great role in its formation, in short, with a view towards algebraic geometry. The author presents a comprehensive view of commutative algebra, from basics, such as localization and primary decomposition, through dimension theory, differentials, homological methods, free resolutions and duality, emphasizing the origins of the ideas and their connections with other parts of mathematics. Many exercises illustrate and sharpen the theory and extended exercises give the reader an active part in complementing the material presented in the text. One novel feature is a chapter devoted to a quick but thorough treatment of Grobner basis theory and the constructive methods in commutative algebra and algebraic geometry that flow from it. Applications of the theory and even suggestions for computer algebra projects are included. This book will appeal to readers from beginners to advanced students of commutative algebra or algeb...

  6. Simplicity and maximal commutative subalgebras of twisted generalized Weyl algebras

    DEFF Research Database (Denmark)

    Hartwig, J.T.; Öinert, Per Johan

    2013-01-01

    In this paper we prove three theorems about twisted generalized Weyl algebras (TGWAs). First, we show that each non-zero ideal of a TGWA has non-zero intersection with the centralizer of the distinguished subalgebra R . This is analogous to earlier results known to hold for crystalline graded rings....... Second, we give necessary and sufficient conditions for the centralizer of R to be commutative (hence maximal commutative), generalizing a result by V. Mazorchuk and L. Turowska. And third, we generalize results by D.A. Jordan and V. Bavula on generalized Weyl algebras by giving necessary and sufficient...... conditions for certain TGWAs to be simple, in the case when R is commutative. We illustrate our theorems by considering some special classes of TGWAs and providing concrete examples. We also discuss how simplicity of a TGWA is related to the maximal commutativity of R and the (non-)existence of non...

  7. Strong Planck constraints on braneworld and non-commutative inflation

    Energy Technology Data Exchange (ETDEWEB)

    Calcagni, Gianluca [Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid (Spain); Kuroyanagi, Sachiko; Ohashi, Junko; Tsujikawa, Shinji, E-mail: calcagni@iem.cfmac.csic.es, E-mail: skuro@rs.tus.ac.jp, E-mail: j1211703@ed.tus.ac.jp, E-mail: shinji@rs.kagu.tus.ac.jp [Department of Physics, Faculty of Science, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan)

    2014-03-01

    We place observational likelihood constraints on braneworld and non-commutative inflation for a number of inflaton potentials, using Planck, WMAP polarization and BAO data. Both braneworld and non-commutative scenarios of the kind considered here are limited by the most recent data even more severely than standard general-relativity models. At more than 95 % confidence level, the monomial potential V(φ)∝φ{sup p} is ruled out for p ≥ 2 in the Randall-Sundrum (RS) braneworld cosmology and, for p > 0, also in the high-curvature limit of the Gauss-Bonnet (GB) braneworld and in the infrared limit of non-commutative inflation, due to a large scalar spectral index. Some parameter values for natural inflation, small-varying inflaton models and Starobinsky inflation are allowed in all scenarios, although some tuning is required for natural inflation in a non-commutative spacetime.

  8. Interactions Between Representation Ttheory, Algebraic Topology and Commutative Algebra

    CERN Document Server

    Pitsch, Wolfgang; Zarzuela, Santiago

    2016-01-01

    This book includes 33 expanded abstracts of selected talks given at the two workshops "Homological Bonds Between Commutative Algebra and Representation Theory" and "Brave New Algebra: Opening Perspectives," and the conference "Opening Perspectives in Algebra, Representations, and Topology," held at the Centre de Recerca Matemàtica (CRM) in Barcelona between January and June 2015. These activities were part of the one-semester intensive research program "Interactions Between Representation Theory, Algebraic Topology and Commutative Algebra (IRTATCA)." Most of the abstracts present preliminary versions of not-yet published results and cover a large number of topics (including commutative and non commutative algebra, algebraic topology, singularity theory, triangulated categories, representation theory) overlapping with homological methods. This comprehensive book is a valuable resource for the community of researchers interested in homological algebra in a broad sense, and those curious to learn the latest dev...

  9. Non-linear Vacuum Phenomena in Non-commutative QED

    CERN Document Server

    Alvarez-Gaumé, Luís

    2001-01-01

    We show that the classic results of Schwinger on the exact propagation of particles in the background of constant field-strengths and plane waves can be readily extended to the case of non-commutative QED. It is shown that non-perturbative effects on constant backgrounds are the same as their commutative counterparts, provided the on-shell gauge invariant dynamics is referred to a non-perturbatively related space-time frame. For the case of the plane wave background, we find evidence of the effective extended nature of non-commutative particles, producing retarded and advanced effects in scattering. Besides the known `dipolar' character of non-commutative neutral particles, we find that charged particles are also effectively extended, but they behave instead as `half-dipoles'.

  10. Non-commutative spheres and numerical quantum mechanics

    CERN Document Server

    Arveson, W

    1992-01-01

    We discuss some basic issues that arise when one attempts to model quantum mechanical systems on a computer, and we describe the mathematical structure of the resulting discretized cannonical commutation relations.

  11. A review of non-commutative gauge theories

    Indian Academy of Sciences (India)

    -commutative space-time operators is reviewed. Examples of 4 theory and QED are then discussed. Problems of extending the theories to () gauge theories and arbitrary charges in QED are considered. Construction of standard model ...

  12. Commuting, Externalities, and the Geographical Sizes of Metropolitan Areas

    OpenAIRE

    Bode, Eckhardt

    2006-01-01

    The paper proposes an econometric approach for quantifying jointly the geographical scope of commuting as well as the various forms of agglomeration economies originating from metropolitan centers. Adopting an urban economics perspective, and using land prices to measure their aggregate effects, the approach estimates the geographical reach of commuting and urban externalities from a hierarchical system of gradient functions. The results for West German NUTS3 regions indicate that metropolita...

  13. Associations between active commuting and physical and mental wellbeing.

    Science.gov (United States)

    Humphreys, David K; Goodman, Anna; Ogilvie, David

    2013-08-01

    To examine whether a relationship exists between active commuting and physical and mental wellbeing. In 2009, cross-sectional postal questionnaire data were collected from a sample of working adults (aged 16 and over) in the Commuting and Health in Cambridge study. Travel behaviour and physical activity were ascertained using the Recent Physical Activity Questionnaire (RPAQ) and a seven-day travel-to-work recall instrument from which weekly time spent in active commuting (walking and cycling) was derived. Physical and mental wellbeing were assessed using the Medical Outcomes Study Short Form survey (SF-8). Associations were tested using multivariable linear regression. An association was observed between physical wellbeing (PCS-8) score and time spent in active commuting after adjustment for other physical activity (adjusted regression coefficients 0.48, 0.79 and 1.21 for 30-149 min/week, 150-224 min/week and ≥ 225 min/week respectively versus actively commuting is associated with higher levels of physical wellbeing. Longitudinal studies should examine the contribution of changing levels of active commuting and other forms of physical activity to overall health and wellbeing. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. On the continuity of the commutative limit of the 4d N=4 non-commutative super Yang–Mills theory

    Directory of Open Access Journals (Sweden)

    Masanori Hanada

    2015-03-01

    Full Text Available We study the commutative limit of the non-commutative maximally supersymmetric Yang–Mills theory in four dimensions (N=4 SYM, where non-commutativity is introduced in the two spacelike directions. The commutative limits of non-commutative spaces are important in particular in the applications of non-commutative spaces for regularisation of supersymmetric theories (such as the use of non-commutative spaces as alternatives to lattices for supersymmetric gauge theories and interpretations of some matrix models as regularised supermembrane or superstring theories, which in turn can play a prominent role in the study of quantum gravity via the gauge/gravity duality. In general, the commutative limits are known to be singular and non-smooth due to UV/IR mixing effects. We give a direct proof that UV effects do not break the continuity of the commutative limit of the non-commutative N=4 SYM to all order in perturbation theory, including non-planar contributions. This is achieved by establishing the uniform convergence (with respect to the non-commutative parameter of momentum integrals associated with all Feynman diagrams appearing in the theory, using the same tools involved in the proof of finiteness of the commutative N=4 SYM.

  15. On the development of a semi-nonparametric generalized multinomial logit model for travel-related choices.

    Science.gov (United States)

    Wang, Ke; Ye, Xin; Pendyala, Ram M; Zou, Yajie

    2017-01-01

    A semi-nonparametric generalized multinomial logit model, formulated using orthonormal Legendre polynomials to extend the standard Gumbel distribution, is presented in this paper. The resulting semi-nonparametric function can represent a probability density function for a large family of multimodal distributions. The model has a closed-form log-likelihood function that facilitates model estimation. The proposed method is applied to model commute mode choice among four alternatives (auto, transit, bicycle and walk) using travel behavior data from Argau, Switzerland. Comparisons between the multinomial logit model and the proposed semi-nonparametric model show that violations of the standard Gumbel distribution assumption lead to considerable inconsistency in parameter estimates and model inferences.

  16. Effects of a school-based intervention on active commuting to school and health-related fitness.

    Science.gov (United States)

    Villa-González, Emilio; Ruiz, Jonatan R; Mendoza, Jason A; Chillón, Palma

    2017-01-05

    Active commuting to school has declined over time, and interventions are needed to reverse this trend. The main objective was to investigate the effects of a school-based intervention on active commuting to school and health-related fitness in school-age children of Southern Spain. A total of 494 children aged 8 to 11 years were invited to participate in the study. The schools were non-randomly allocated (i.e., school level allocation) into the experimental group (EG) or the control group (CG). The EG received an intervention program for 6 months (a monthly activity) focused on increasing the level of active commuting to school and mainly targeting children's perceptions and attitudes. Active commuting to school and health-related fitness (i.e., cardiorespiratory fitness, muscular fitness and speed-agility), were measured at baseline and at the end of the intervention. Children with valid data on commuting to school at baseline and follow-up, sex, age and distance from home to school were included in the final analysis (n = 251). Data was analyzed through a factorial ANOVA and the Bonferroni post-hoc test. At follow up, the EG had higher rates of cycling to school than CG for boys only (p = 0.04), but not for walking to school for boys or girls. The EG avoided increases in the rates of passive commuting at follow up, which increased in the CG among girls for car (MD = 1.77; SE = 0.714; p = 0.010) and bus (MD = 1.77; SE = 0.714; p = 0.010) modes. Moreover, we observed significant interactions and main effects between independent variables (study group, sex and assessment time point) on health-related fitness (p fitness. However, the school-based intervention avoided increases in rates of passive commuting in the experimental group, which were significantly increased in girls of the control group.

  17. The active commuting route environment scale (ACRES: development and evaluation

    Directory of Open Access Journals (Sweden)

    Stigell Erik

    2010-07-01

    Full Text Available Abstract Background Route environments can be a potentially important factor in influencing people's behaviours in relation to active commuting. To better understand these possible relationships, assessments of route environments are needed. We therefore developed a scale; the Active Commuting Route Environment Scale (ACRES, for the assessment of bicyclists' and pedestrians' perceptions of their commuting route environments. Here we will report on the development and the results of validity and reliability assessments thereof. Methods Active commuters (n = 54 were recruited when they bicycled in Stockholm, Sweden. Traffic planning and environmental experts from the Municipality of Stockholm were assembled to form an expert panel (n = 24. The active commuters responded to the scale on two occasions, and the expert panel responded to it once. To test criterion-related validity, differences in ratings of the inner urban and suburban environments of Greater Stockholm were compared between the experts and the commuters. Furthermore, four items were compared with existing objective measures. Test-retest reproducibility was assessed with three types of analysis: order effect, typical error and intraclass correlation. Results There was a concordance in sizes and directions of differences in ratings of inner urban and suburban environments between the experts and the commuters. Furthermore, both groups' ratings were in line with existing objectively measured differences between the two environmental settings. Order effects between test and retest were observed in 6 of 36 items. The typical errors ranged from 0.93 to 2.54, and the intraclass correlation coefficients ranged from 'moderate' (0.42 to 'almost perfect' (0.87. Conclusions The ACRES was characterized by considerable criterion-related validity and reasonable test-retest reproducibility.

  18. Spiral Tube Assembly for High-Speed Countercurrent Chromatography: Choice of Elution Modes for Four Typical Two-Phase Solvent Systems.

    Science.gov (United States)

    Ito, Y; Clary, R; Powell, J; Knight, M; Finn, T M

    2008-01-01

    Optimal elution modes were determined for four typical two-phase solvent systems each with different physical parameters to achieve the best peak resolution and retention of the stationary phase by spiral tube high-speed countercurrent chromatography using a suitable set of test samples. Both retention of the stationary phase and partition efficiency are governed by an interplay between two forces, i.e., Archimedean Screw force and radial centrifugal force gradient of the spiral channel. In the polar solvent system represented by 1-butanol./acetic acid/water (4:1:5, v/v/v) with settling time of over 30 s, the effect by the radial centrifugal gradient force dominates giving the best separation of dipeptides either by pumping the lower phase from the inner terminal or the upper phase from the outer terminal of the spiral channel. In the moderately hydrophobic two-phase solvent system represented by hexane/ethyl acetate/methanol/0.1 M HCl (1:1:1:1) with settling time of 19 s, and two hydrophobic solvent systems of hexane/ethanol/water (5:4:1, v/v/v) and non-aqueous binary system of hexane/acetonitrile both having settling time of 9, the effect of the Archimedean screw force play a major role in hydrodynamic equilibrium, giving the best separations by pumping the lower phase from the head or the upper phase from the tail of the spiral channel.

  19. Commuters' exposure to PM 2.5, CO, and benzene in public transport in the metropolitan area of Mexico City

    Science.gov (United States)

    Gómez-Perales, J. E.; Colvile, R. N.; Nieuwenhuijsen, M. J.; Fernández-Bremauntz, A.; Gutiérrez-Avedoy, V. J.; Páramo-Figueroa, V. H.; Blanco-Jiménez, S.; Bueno-López, E.; Mandujano, F.; Bernabé-Cabanillas, R.; Ortiz-Segovia, E.

    A survey was carried out to measure commuters' exposure to PM 2.5, CO, benzene, and the chemical composition of PM 2.5 on different routes and modes of transport in Mexico City. PM 2.5 ( n=62), CO ( n=54) and benzene ( n=22) are presented from morning (6:30-9:30 a.m.) and evening (17:30-20:30) rush hours on minibuses, buses and Metro (underground or subway system). Three routes were selected from a previous commuters' exposure study covering some of the most important thoroughfares of the valley. For PM 2.5, mass concentration was determined for all the samples. Nitrates, sulphates, inorganic elements and carbon fraction were analysed. CO was sampled using electrochemical sensors and 6-l canisters with flow controller devices were used to collect integrated samples for benzene. Minibuses had a slightly higher geometric mean PM 2.5 concentration in the morning than other modes of transport, but the ranking of geometric mean PM 2.5 by mode of transport is opposite in the evening and the variability within modes is approximately double the difference between modes. The highest single measurement was a concentration of 137 μg m -3 on a bus during an evening rush hour. The main component identified in PM 2.5 was carbon. Carbon monoxide levels in this study were approximately 3 times lower than those found in a commuter exposure study conducted in 1991. A strong association was shown between wind speed and PM 2.5 exposure in minibuses ( r2=0.50) and buses ( r2=0.54). The relationship between wind speed and CO exposure was strong only in minibuses ( r2=0.52).

  20. Existence of stable wormholes on a non-commutative-geometric background in modified gravity

    Energy Technology Data Exchange (ETDEWEB)

    Zubair, M.; Mustafa, G. [COMSATS, Institute of Information Technology, Department of Mathematics, Lahore (Pakistan); Waheed, Saira [Prince Mohammad Bin Fahd University, Al Khobar (Saudi Arabia); Abbas, G. [The Islamia University of Bahawalpur, Department of Mathematics, Bahawalpur (Pakistan)

    2017-10-15

    In this paper, we discuss spherically symmetric wormhole solutions in f(R, T) modified theory of gravity by introducing well-known non-commutative geometry in terms of Gaussian and Lorentzian distributions of string theory. For analytic discussion, we consider an interesting model of f(R, T) gravity defined by f(R, T) = f{sub 1}(R) + λT. By taking two different choices for the function f{sub 1}(R), that is, f{sub 1}(R) = R and f{sub 1}(R) = R + αR{sup 2} + γR{sup n}, we discuss the possible existence of wormhole solutions. In the presence of non-commutative Gaussian and Lorentzian distributions, we get exact and numerical solutions for both these models. By taking appropriate values of the free parameters, we discuss different properties of these wormhole models analytically and graphically. Further, using an equilibrium condition, it is found that these solutions are stable. Also, we discuss the phenomenon of gravitational lensing for the exact wormhole model and it is found that the deflection angle diverges at the wormhole throat. (orig.)

  1. Evaluation of new mixed-mode UHPLC stationary phases and the importance of stationary phase choice when using low ionic-strength mobile phase additives.

    Science.gov (United States)

    Nováková, Lucie; Vlčková, Hana; Petr, Solich

    2012-05-15

    In this study, the selectivity, retention properties, peak shape and loading capacity for bases were practically evaluated using two UHPLC mixed-mode hybrid CSH stationary phases modified by C18 or Phenyl group. The data were compared with the data obtained on other UHPLC hybrid stationary phases (BEH C18, BEH C8, BEH Phenyl and BEH Shield RP18) at both basic and acidic conditions using conventional HPLC buffers (50mM ammonium formate/acetate) as well as low ionic-strength additives such as, e.g. 0.1-0.01% formic/acetic acid and 1mM solution of ammonium formate/acetate, which are widely used in LC-MS applications. Ten pharmaceutically important compounds encompassing acids, bases and neutral were included into the study. Due to properties of CSH sorbent (which possess positively charged surface besides RP group), much improved peak shapes and weaker retention was obtained for bases even at very low concentration of acidic additives. Such conditions are ideally suited for LC-MS analysis of bases, where typical RP chromatographic separation (retention and good selectivity at basic pH) and LS-MS conditions (efficient ionization at acidic pH) are not in agreement. On the other hand, acids were more strongly retained and for some compounds the peak shape was influenced negatively due to ion-exchange mechanism. Further, the behavior of acidic, basic and neutral solutes is discussed using various additives at both basic and acidic pH for all above stated columns. The robustness of retention times after pH change from basic to acidic was also evaluated. The new CSH stationary phases represent an interesting selectivity tool preferably for separation of basic compounds. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Geometric properties of commutative subalgebras of partial differential operators

    Science.gov (United States)

    Zheglov, A. B.; Kurke, H.

    2015-05-01

    We investigate further algebro-geometric properties of commutative rings of partial differential operators, continuing our research started in previous articles. In particular, we start to explore the simplest and also certain known examples of quantum algebraically completely integrable systems from the point of view of a recent generalization of Sato's theory, developed by the first author. We give a complete characterization of the spectral data for a class of 'trivial' commutative algebras and strengthen geometric properties known earlier for a class of known examples. We also define a kind of restriction map from the moduli space of coherent sheaves with fixed Hilbert polynomial on a surface to an analogous moduli space on a divisor (both the surface and the divisor are part of the spectral data). We give several explicit examples of spectral data and corresponding algebras of commuting (completed) operators, producing as a by-product interesting examples of surfaces that are not isomorphic to spectral surfaces of any (maximal) commutative ring of partial differential operators of rank one. Finally, we prove that any commutative ring of partial differential operators whose normalization is isomorphic to the ring of polynomials k \\lbrack u,t \\rbrack is a Darboux transformation of a ring of operators with constant coefficients. Bibliography: 39 titles.

  3. Multi-commutation in flow analysis: recent developments and applications.

    Science.gov (United States)

    Feres, Mário A; Fortes, Paula R; Zagatto, Elias A G; Santos, João L M; Lima, José L F C

    2008-06-16

    The concept of multi-commutation in flow analysis is revisited, and emphasis is given to recent methodological and applicative achievements. Multi-commutation is compatible with different flow patterns (unsegmented, segmented, pulsed, tandem) and amenable to concentration-oriented feedback mechanisms. Its exploitation has led to significant attainments mainly in relation to versatility of the flow system. Characteristics and potentialities of the multi-commuted flow systems are discussed, and guidelines for assisting methodological implementation are given. The number of applications has experienced remarkable increase during last years; therefore, the applicative part of this review is focused on the recent noteworthy applications, mainly in relation to environmental, agronomical, pharmaceutical, biological, food and industrial samples.

  4. Non-topological non-commutativity in string theory

    CERN Document Server

    Guttenberg, Sebastian; Kreuzer, Maximilian; Rashkov, Radoslav

    2007-01-01

    Quantization of coordinates leads to the non-commutative product of deformation quantization, but is also at the roots of string theory, for which space-time coordinates become the dynamical fields of a two-dimensional conformal quantum field theory. Appositely, open string diagrams provided the inspiration for Kontsevich's solution of the long-standing problem of quantization of Poisson geometry by virtue of his formality theorem. In the context of D-brane physics non-commutativity is not limited, however, to the topolocial sector. We show that non-commutative effective actions still make sense when associativity is lost and establish a generalized Connes-Flato-Sternheimer condition through second order in a derivative expansion. The measure in general curved backgrounds is naturally provided by the Born--Infeld action and reduces to the symplectic measure in the topological limit, but remains non-singular even for degenerate Poisson structures. Analogous superspace deformations by RR--fields are also discus...

  5. Optimization of polynomials in non-commuting variables

    CERN Document Server

    Burgdorf, Sabine; Povh, Janez

    2016-01-01

    This book presents recent results on positivity and optimization of polynomials in non-commuting variables. Researchers in non-commutative algebraic geometry, control theory, system engineering, optimization, quantum physics and information science will find the unified notation and mixture of algebraic geometry and mathematical programming useful. Theoretical results are matched with algorithmic considerations; several examples and information on how to use NCSOStools open source package to obtain the results provided. Results are presented on detecting the eigenvalue and trace positivity of polynomials in non-commuting variables using Newton chip method and Newton cyclic chip method, relaxations for constrained and unconstrained optimization problems, semidefinite programming formulations of the relaxations and finite convergence of the hierarchies of these relaxations, and the practical efficiency of algorithms.

  6. Changes to urban form and commuting patterns: trends in two Danish city regions

    DEFF Research Database (Denmark)

    Nielsen, Thomas Alexander Sick

    2015-01-01

    This paper compares indicators of polycentricity in a monocentric (MUR) and a polycentric urban region (PUR) in Denmark at two points in time (1982 and 2002). It describes how population, jobs and commuting indicators of polycentricity develop and interact over time. Both the MUR and the PUR tend...... towards more balanced development. The increasing size of the main node in the PUR is the only deviation from the general trend. The general tendency towards a more polycentric regional structure was most marked in changing interaction and commuting patterns. Inter-urban commuting increased, while intra......-urban commuting decreased, leading to dispersion of commuters and a rapid increase in commuting across the region. Commuting distances were shortest in the polycentric region, but it also had the highest growth rates. In both regions, the balancing trend leads to a dispersal of commuting demand over...

  7. An Economic Geography of the United States: From Commutes to Megaregions.

    Science.gov (United States)

    Dash Nelson, Garrett; Rae, Alasdair

    2016-01-01

    The emergence in the United States of large-scale "megaregions" centered on major metropolitan areas is a phenomenon often taken for granted in both scholarly studies and popular accounts of contemporary economic geography. This paper uses a data set of more than 4,000,000 commuter flows as the basis for an empirical approach to the identification of such megaregions. We compare a method which uses a visual heuristic for understanding areal aggregation to a method which uses a computational partitioning algorithm, and we reflect upon the strengths and limitations of both. We discuss how choices about input parameters and scale of analysis can lead to different results, and stress the importance of comparing computational results with "common sense" interpretations of geographic coherence. The results provide a new perspective on the functional economic geography of the United States from a megaregion perspective, and shed light on the old geographic problem of the division of space into areal units.

  8. Choice experiments

    Science.gov (United States)

    Thomas P Holmes; Wiktor L Adamawicz; Fredrik Carlsson

    2017-01-01

    There has been an explosion of interest during the past two decades in a class of nonmarket stated-preference valuation methods known as choice experiments. The overall objective of a choice experiment is to estimate economic values for characteristics (or attributes) of an environmental good that is the subject of policy analysis, where...

  9. Non-Commutative Homometry in the Dihedral Groups

    OpenAIRE

    Genuys, Grégoire

    2017-01-01

    The paper deals with the question of homometry in the dihedral groups $D_{n}$ of order $2n$. These groups have the specificity to be non-commutative. It leads to a new approach as compared as the one used in the traditional framework of the commutative group $ \\mathbb{Z}_{n}$. We give here a musical interpretation of homometry in $D_{12}$ using the well-known neo-Riemannian groups, some computational results concerning enumeration of homometric sets for small values of $n$, and some propertie...

  10. Exotic Galilean Symmetry and Non-Commutative Mechanics

    Directory of Open Access Journals (Sweden)

    Peter A. Horváthy

    2010-07-01

    Full Text Available Some aspects of the ''exotic'' particle, associated with the two-parameter central extension of the planar Galilei group are reviewed. A fundamental property is that it has non-commuting position coordinates. Other and generalized non-commutative models are also discussed. Minimal as well as anomalous coupling to an external electromagnetic field is presented. Supersymmetric extension is also considered. Exotic Galilean symmetry is also found in Moyal field theory. Similar equations arise for a semiclassical Bloch electron, used to explain the anomalous/spin/optical Hall effects.

  11. Powers of a product of commutators as products of squares

    Directory of Open Access Journals (Sweden)

    Alireza Abdollahi

    2004-01-01

    Full Text Available We prove that for any odd integer N and any integer n>0, the Nth power of a product of n commutators in a nonabelian free group of countable infinite rank can be expressed as a product of squares of 2n+1 elements and, for all such odd N and integers n, there are commutators for which the number 2n+1 of squares is the minimum number such that the Nth power of its product can be written as a product of squares. This generalizes a recent result of Akhavan-Malayeri.

  12. Modular Theory, Non-Commutative Geometry and Quantum Gravity

    Directory of Open Access Journals (Sweden)

    Wicharn Lewkeeratiyutkul

    2010-08-01

    Full Text Available This paper contains the first written exposition of some ideas (announced in a previous survey on an approach to quantum gravity based on Tomita-Takesaki modular theory and A. Connes non-commutative geometry aiming at the reconstruction of spectral geometries from an operational formalism of states and categories of observables in a covariant theory. Care has been taken to provide a coverage of the relevant background on modular theory, its applications in non-commutative geometry and physics and to the detailed discussion of the main foundational issues raised by the proposal.

  13. Associations between long commutes and subjective health complaints among railway workers in Norway.

    Science.gov (United States)

    Urhonen, Terhi; Lie, Arve; Aamodt, Geir

    2016-12-01

    Commuting is an important aspect of daily life for many employees, but there is little knowledge of how this affects individual commuters' health and well-being. The authors investigated the relationship between commuting and subjective health complaints, using data from a web-based questionnaire. In a sample of 2126 railway employees, 644 (30.3%) had long commute times. A 29-item inventory was used to measure the number and degree of the subjective health complaints. Those who commuted 60 min or more each way were characterized by significantly higher numbers and degrees of subjective health complaints compared with their peers with short commutes. The mean number of complaints was 7.5 among the former group and 6.4 for the latter group (p = 0.009). In a regression model, in which the authors controlled for age, gender, education, self-rated health, and coping, the employees with long commutes reported more complaints than those with short commutes. Significant associations were found between those with long commutes and the number and degree of incidences of self-reported musculoskeletal pain, pseudo-neurologic complaints, and gastrointestinal problems. Commuters who had had long commutes for more than 10 years reported more gastrointestinal and musculoskeletal complaints than those with long commutes for less than 2 years. Also, commuters with long commutes spent less time with their families and leisure activities compared with those with short commutes. The authors conclude that the association between long commute times and higher levels of subjective health complaints should attract the attention of transport planners, employers, and public health policymaker.

  14. Associations between long commutes and subjective health complaints among railway workers in Norway

    Directory of Open Access Journals (Sweden)

    Terhi Urhonen

    2016-12-01

    Full Text Available Commuting is an important aspect of daily life for many employees, but there is little knowledge of how this affects individual commuters' health and well-being. The authors investigated the relationship between commuting and subjective health complaints, using data from a web-based questionnaire. In a sample of 2126 railway employees, 644 (30.3% had long commute times. A 29-item inventory was used to measure the number and degree of the subjective health complaints. Those who commuted 60 min or more each way were characterized by significantly higher numbers and degrees of subjective health complaints compared with their peers with short commutes. The mean number of complaints was 7.5 among the former group and 6.4 for the latter group (p = 0.009. In a regression model, in which the authors controlled for age, gender, education, self-rated health, and coping, the employees with long commutes reported more complaints than those with short commutes. Significant associations were found between those with long commutes and the number and degree of incidences of self-reported musculoskeletal pain, pseudo-neurologic complaints, and gastrointestinal problems. Commuters who had had long commutes for more than 10 years reported more gastrointestinal and musculoskeletal complaints than those with long commutes for less than 2 years. Also, commuters with long commutes spent less time with their families and leisure activities compared with those with short commutes. The authors conclude that the association between long commute times and higher levels of subjective health complaints should attract the attention of transport planners, employers, and public health policymaker.

  15. The commuter family as a geographical adaptive strategy for the work-family balance

    NARCIS (Netherlands)

    van der Klis, M.; Karsten, L.

    2009-01-01

    In this paper we raise the question of how commuter families create a work-family balance in a situation of incongruity of the geographical scales of work and family. Commuter families combine the work location of a commuting parent on the (inter)national scale, with the home-based parent's work

  16. 49 CFR 37.85 - Purchase or lease of new intercity and commuter rail cars.

    Science.gov (United States)

    2010-10-01

    ... rail cars. 37.85 Section 37.85 Transportation Office of the Secretary of Transportation TRANSPORTATION....85 Purchase or lease of new intercity and commuter rail cars. Amtrak or a commuter authority making a solicitation after August 25, 1990, to purchase or lease a new intercity or commuter rail car for use on the...

  17. 14 CFR 135.398 - Commuter category airplanes performance operating limitations.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Commuter category airplanes performance... ON BOARD SUCH AIRCRAFT Airplane Performance Operating Limitations § 135.398 Commuter category airplanes performance operating limitations. (a) No person may operate a commuter category airplane unless...

  18. 20 CFR 704.102 - Commutation of payments to aliens and nonresidents.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Commutation of payments to aliens and... LHWCA EXTENSIONS Defense Base Act § 704.102 Commutation of payments to aliens and nonresidents. Authority to commute payments to aliens and nonnationals who are not residents of the United States and...

  19. Active Commuting to School as a Source of Health Promotion ...

    African Journals Online (AJOL)

    user

    and mobility challenges were excluded from the study. The selected students were provided with packets containing the consent forms to be completed by the students and their parents; and the active commuting questionnaire to be completed by the students. A total of 926 (84.2%) out of the 1100 students who received the ...

  20. A new method of converter transformer protection without commutation failure

    Science.gov (United States)

    Zhang, Jiayu; Kong, Bo; Liu, Mingchang; Zhang, Jun; Guo, Jianhong; Jing, Xu

    2018-01-01

    With the development of AC / DC hybrid transmission technology, converter transformer as nodes of AC and DC conversion of HVDC transmission technology, its reliable safe and stable operation plays an important role in the DC transmission. As a common problem of DC transmission, commutation failure poses a serious threat to the safe and stable operation of power grid. According to the commutation relation between the AC bus voltage of converter station and the output DC voltage of converter, the generalized transformation ratio is defined, and a new method of converter transformer protection based on generalized transformation ratio is put forward. The method uses generalized ratio to realize the on-line monitoring of the fault or abnormal commutation components, and the use of valve side of converter transformer bushing CT current characteristics of converter transformer fault accurately, and is not influenced by the presence of commutation failure. Through the fault analysis and EMTDC/PSCAD simulation, the protection can be operated correctly under the condition of various faults of the converter.

  1. On additive groups of associative and commutative rings ...

    African Journals Online (AJOL)

    The characterization of (A)CR-groups studied by Shalom Feigelstock [`Additive groups of commutative rings', Quaest. Math. 23 (2000), 241-245] is complemented. In particular, the theorem characterizing mixed ACR-groups is proved and numerous new examples of (A)CR-group are given. Abelian groups A such that any ...

  2. Standards and Guidelines for Commuter Student Programs and Services.

    Science.gov (United States)

    NASPA Journal, 1986

    1986-01-01

    In describing standards and guidelines for commuter student programs and services, an analysis is provided of the mission, the program, multicultural programs and services, leadership and management, organization and administration, human resources, funding, facilities, legal responsibilities, equal opportunity, access and affirmative action,…

  3. The spectral theory of commutative C*-algebras: the constructive ...

    African Journals Online (AJOL)

    ... theory which expresses one's natural intuition of the notion involved, and then to establish various properties, leading up to the final result, by formal reasoning within these theories. Keywords: locale; commutative C*-algebra; spectrum; propositional geometric theory; constructive; Gelfand duality; Gelfand-Mazur theorem

  4. A characterization of semiprojectivity for commutative C*-algebras

    DEFF Research Database (Denmark)

    Sørensen, Adam Peder Wie; Theil, Hannes

    2012-01-01

    Given a compact metric space X, we show that the commutative C*-algebra C(X) is semiprojective if and only if X is an absolute neighbourhood retract of dimension at most 1. This confirms a conjecture of Blackadar. Generalizing to the non-unital setting, we derive a characterization of semiproject...

  5. African Women Commuter Traders in Nairobi in the First Decade ...

    African Journals Online (AJOL)

    This article investigates African women commuter trading activities in Nairobi in the first decade after World War One. Its findings derive mainly from a research project carried out in 1989-1996. The major source of data for the study was oral interviews with the women who traded in Nairobi during the years under study, ...

  6. coincidentally commuting mappings in D-metric spaces

    Directory of Open Access Journals (Sweden)

    B. C. Dhage

    2003-01-01

    pairs of a single-valued and a multivalued coincidentally commuting mappings in D-metric spaces satisfying a certain generalized contraction condition. Our result generalizes more than a dozen known fixed-point theorems in D-metric spaces including those of Dhage (2000 and Rhoades (1996.

  7. Exploratory mapping of commuter flows in England and Wales

    DEFF Research Database (Denmark)

    Nielsen, Thomas Alexander Sick; Hovgesen, Henrik Harder; Lassen, Claus

    2005-01-01

    and Birmingham. These are chosen for their size and differences in regional context. In the general analysis – at the country-wide scale - special emphasis is put on deriving a representation of the scale and the corridors of interaction from the relatively disaggregate data. A map of commuter flows in England...

  8. Limits of commutative triangular systems on locally compact groups

    Indian Academy of Sciences (India)

    Keywords. Embeddable measures; triangular systems of measures; infinitesimally divisible measures; totally disconnected groups; real algebraic groups. 1. Introduction. Commutative triangular systems of probability measures on locally compact groups have been studied extensively and recently the embedding of the limit ...

  9. A review of non-commutative gauge theories

    Indian Academy of Sciences (India)

    Abstract. Construction of quantum field theory based on operators that are functions of non- commutative space-time operators is reviewed. Examples of φ4 theory and QED are then discussed. Problems of extending the theories toSU´Nµ gauge theories and arbitrary charges in QED are consid- ered. Construction of ...

  10. Preferences for housing, jobs, and commuting : A mixed logit analysis

    NARCIS (Netherlands)

    Rouwendal, J.; Meijer, Erik

    This paper reports stated preferences of Dutch workers for combinations of housing, employment, and commuting. The analysis uses standard logit models as well as mixed logit models. Estimation results offer insights into the relative importance of various aspects of housing, employment, and

  11. Preferences for Housing, Jobs and Commuting: A Mixed Logit Analysis

    NARCIS (Netherlands)

    Rouwendal, J.; Meijer, E.

    2001-01-01

    This paper reports stated preferences of Dutch workers for combinations of housing, employment, and commuting. The analysis uses standard logit models as well as mixed logit models. Estimation results offer insights into the relative importance of various aspects of housing, employment, and

  12. Einstein–Podolski–Rosen paradox, non-commuting operator ...

    Indian Academy of Sciences (India)

    Einstein, Podolski and Rosen (EPR) have shown that any wavefunction (subject to the Schrödinger equation) can describe the physical reality completely, and any two observables associated with two non-commuting operators can have simultaneous reality. In contrast, quantum theory claims that the wavefunction can ...

  13. Exploring characteristics and motives of long distance commuter cyclists

    DEFF Research Database (Denmark)

    Hansen, Karsten Bruun; Sick Nielsen, Thomas

    2014-01-01

    are very positive about their commute - pointing to positive experiences, better mood, and stress relief as experiences related to their cycle trip to work. Policy support should devote attention to unlocking the potential that may be embedded in individuals combining their exercise and travel time...

  14. The M5-brane and non-commutative open strings

    NARCIS (Netherlands)

    Bergshoeff, E.; Berman, D.S.; Schaar, J.P. van der; Sundell, P.

    2001-01-01

    The M-theory origin of non-commutative open-string theory is examined by investigating the M-theory 5-brane at near critical field strength. In particular, it is argued that the open-membrane metric provides the appropriate moduli when calculating the duality relations between M and II

  15. Regenerative Snubber For GTO-Commutated SCR Inverter

    Science.gov (United States)

    Rippel, Wally E.; Edwards, Dean B.

    1992-01-01

    Proposed regenerative snubbing circuit substituted for dissipative snubbing circuit in inverter based on silicon controlled rectifiers (SCR's) commutated by gate-turn-off thyristor (GTO). Intended to reduce loss of power that occurs in dissipative snubber. Principal criteria in design: low cost, simplicity, and reliability.

  16. Decreasing the commutation failure frequency in HVDC transmission systems

    DEFF Research Database (Denmark)

    Hansen (retired June, 2000), Arne; Havemann (retired June, 2000), Henrik

    2000-01-01

    In this paper we show how a fairly large proportion of those commutation failures that are due to single-phased short circuits to earth can be avoided. In a control circuit based on a digital signal processor (DSP) it is possible, with instantaneous results, to switch from a normal control strategy...

  17. Study of an intraurban travel demand model incorporating commuter preference variables

    Science.gov (United States)

    Holligan, P. E.; Coote, M. A.; Rushmer, C. R.; Fanning, M. L.

    1971-01-01

    The model is based on the substantial travel data base for the nine-county San Francisco Bay Area, provided by the Metropolitan Transportation Commission. The model is of the abstract type, and makes use of commuter attitudes towards modes and simple demographic characteristics of zones in a region to predict interzonal travel by mode for the region. A characterization of the STOL/VTOL mode was extrapolated by means of a subjective comparison of its expected characteristics with those of modes characterized by the survey. Predictions of STOL demand were made for the Bay Area and an aircraft network was developed to serve this demand. When this aircraft system is compared to the base case system, the demand for STOL service has increased five fold and the resulting economics show considerable benefit from the increased scale of operations. In the previous study all systems required subsidy in varying amounts. The new system shows a substantial profit at an average fare of $3.55 per trip.

  18. Analysis of Subway Interior Noise at Peak Commuter Time.

    Science.gov (United States)

    Lee, Donguk; Kim, Gibbeum; Han, Woojae

    2017-07-01

    Although mass transit systems are convenient and efficient for urban people, little attention has been paid to the potential hearing hazard from their noise. The purpose of the current study was to measure and analyze levels of subway interior noise at peak commuter times and to provide information about commuters' daily dose of noise exposure. To measure the subway interior noise, nine subway lines inside Seoul (i.e., lines 1-9) and six lines surrounding the capital city area (i.e., Central, Bundang, Sinbundang, Incheon, Gyeongui, and Gyeongchun) were chosen. The noise was measured and recorded by a sound level meter for two-hour periods in the morning and evening. 1) In the LZeq analysis, the average noise level of all 15 lines was 72.78 dB; the maximum and minimum noise levels were 78.34 and 62.46 dB, respectively. The average noise level of the nine lines inside Seoul was 73.45 dB, which was 1.68-dB louder than that of the six lines surrounding the capital city area. 2) Based on the LZeq analysis of 33 measured frequencies, 12.5 Hz was the highest frequency and 20,000 Hz was the lowest. 3) There was no remarkable difference in the level of subway interior noise between morning and evening peak commuter times. We concluded that the level of subway interior noise was not loud enough for commuters to incur noise-induced hearing loss. Regardless, environmental noise control efforts in the subway system might be needed for commuters who take a subway every day.

  19. Longitudinal associations of active commuting with wellbeing and sickness absence.

    Science.gov (United States)

    Mytton, Oliver Tristan; Panter, Jenna; Ogilvie, David

    2016-03-01

    Our aim was to explore longitudinal associations of active commuting (cycling to work and walking to work) with physical wellbeing (PCS-8), mental wellbeing (MCS-8) and sickness absence. We used data from the Commuting and Health in Cambridge study (2009 to 2012; n=801) to test associations between: a) maintenance of cycling (or walking) to work over a one year period and indices of wellbeing at the end of that one year period; and b) associations between change in cycling (or walking) to work and change in indices of wellbeing. Linear regression was used for testing associations with PCS-8 and MCS-8, and negative binomial regression for sickness absence. After adjusting for sociodemographic variables, physical activity and physical limitation, those who maintained cycle commuting reported lower sickness absence (0.46, 95% CI: 0.14-0.80; equivalent to one less day per year) and higher MCS-8 scores (1.50, 0.10-2.10) than those who did not cycle to work. The association for sickness absence persisted after adjustment for baseline sickness absence. No significant associations were observed for PCS-8. Associations between change in cycle commuting and change in indices of wellbeing were not significant. No significant associations were observed for walking. This work provides some evidence of the value of cycle commuting in improving or maintaining the health and wellbeing of adults of working age. This may be important in engaging employers in the promotion of active travel and communicating the benefits of active travel to employees. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Long distance transportation patterns : mode choice

    Science.gov (United States)

    2006-05-01

    Americans total 1.3 trillion person-miles of long distance travel a year on about 2.6 : billion long-distance trips. Long-distance trips are journeys of more than 50 miles : from home to the furthest destination. More than half of long-distance trips...

  1. A discussion of mode choice models

    DEFF Research Database (Denmark)

    Nielsen, Otto Anker

    Artiklen diskuterer matematiske modeller for transportmiddelvalg med særlig fokus på modeller, der bygger på nyttefunktioner. I kapitel 3 refereres til et begrænset eksperiment, der viste at den sædvanlige lineære nyttefunktion ikke er tilstrækkelig til at beskrive selv en meget simpel valgsituat...

  2. The relationship between urban neighbourhood type and commuting distance in Gauteng City region, South Africa. A preliminary analysis

    CSIR Research Space (South Africa)

    Moselakgomo, M

    2013-07-01

    Full Text Available preliminary analysis of the 2013 Gauteng household survey data showed that the road based motorised transport modes were dominant for home-to-work trips, accounting for about 80% of the total home-to-work trips. Proportion of private car was found to be high... in 2013 than in 2001 (Gauteng Household Travel Survey Report, 2014). The increase in private car use could be indicative of increasing commuting distances, as longer trips are likely to be made by car. 1.2 Problem statement and research...

  3. Cultural distance and entry mode choices of german companies from the automotive industry in Brazil Distância cultural e escolha do modo de entrada de empresas alemãs do setor automobilístico no Brasil

    Directory of Open Access Journals (Sweden)

    Gilberto Sarfati

    2013-05-01

    Full Text Available This study has as objective to analyze the relation between the national culture distance between Brazil and Germany and the market entry mode chosen by this companies when penetrating the Brazilian automotive market. In order to develop the study, literature and academic articles have been consulted as a way to understand the multinationals and internationalization process, but mainly the relation between national culture distance and the choice of the market entry mode of companies willing to penetrate foreign markets, based on the research of Kogut and Singh (1988 and Brouthers and Brouthers (2001. The field study was developed in two main steps: the first one was an online survey designated to the 30 companies of the analyzed universe and two semi-structured interviews administrated to one German automaker and one auto parts company, aiming to go deeper into the information extracted from the questionnaire sent. The obtained results enabled the acknowledgment of a fundamental relation between the automakers presence in Brazil and the attraction of the auto parts companies to the Brazilian market, as well as the relation between the entrance of these companies and the economic cycle, in which Brazil was inserted at that moment. And finally confirm the relation between national culture distance, investment risk perception, and wholly-owned market entry mode choices.  Esta pesquisa tem o objetivo de analisar a relação estabelecida pela distância da cultura nacional entre Brasil e Alemanha e o modo de entrada escolhido por empresas alemãs ao penetrarem o mercado brasileiro, tendo como objeto de análise as empresas pertencentes ao setor automobilístico. Para o desenvolvimento deste trabalho, foram utilizadas pesquisas bibliográficas visando a entender as multinacionais e o processo de internacionalização, e, principalmente, a relação entre cultura nacional e a escolha do modo de entrada de empresas em mercados externos a partir de

  4. The equationally-defined commutator a study in equational logic and algebra

    CERN Document Server

    Czelakowski, Janusz

    2015-01-01

    This monograph introduces and explores the notions of a commutator equation and the equationally-defined commutator from the perspective of abstract algebraic logic.  An account of the commutator operation associated with equational deductive systems is presented, with an emphasis placed on logical aspects of the commutator for equational systems determined by quasivarieties of algebras.  The author discusses the general properties of the equationally-defined commutator, various centralization relations for relative congruences, the additivity and correspondence properties of the equationally-defined commutator, and its behavior in finitely generated quasivarieties. Presenting new and original research not yet considered in the mathematical literature, The Equationally-Defined Commutator will be of interest to professional algebraists and logicians, as well as graduate students and other researchers interested in problems of modern algebraic logic.

  5. Reductions in commuter exposure to volatile organic compounds in Mexico City due to the environmental program ProAire2002-2010.

    Science.gov (United States)

    Shinohara, Naohide; Ángeles, Felipe; Basaldud, Roberto; Cardenas, Beatriz; Wakamatsu, Shinji

    2017-05-01

    We investigated commuter exposure to volatile organic compounds in the metropolitan area of Mexico City in 2011 in private car, microbus, bus, metro, metrobus, and trolley bus. A similar survey was conducted in 2002 before initiation of the ProAire2002-2010 program aimed at reducing air pollution. Formaldehyde, acetaldehyde, benzene, toluene, ethylbenzene, m/p-xylene, and o-xylene were sampled while traveling during the morning rush hour in May 2011. Compared with the 2002 survey, in-vehicle concentrations were substantially lower in 2011, except for formaldehyde in microbuses (35% higher than in 2002). The reductions were 17-42% (except microbuses), 25-44%, 41-61%, 43-61%, 71-79%, 80-91%, and 79-93% for formaldehyde, acetaldehyde, benzene, toluene, ethylbenzene, m/p-xylene, and o-xylene, respectively. These reductions are considered to be the outcome of some of the actions in the ProAire2002-2010 program. In some microbuses, use of liquid petroleum gas may have increased in-vehicle formaldehyde concentrations. The reduction in predicted excess cancer incidence of commuters because of ProAire2002-2010 was estimated to be 1.4 cases/yr. In addition, if every microbus commuter changed their transport mode to bus, metro, or metrobus in the future, the estimated excess cancer incidence of commuters could be further decreased from 6.4 to 0.88-2.2 cases/year.

  6. Market Signals: Evidence on the Determinants and Consequences of School Choice from a Citywide Lottery

    Science.gov (United States)

    Glazerman, Steven; Dotter, Dallas

    2017-01-01

    We estimate school-choice preferences revealed by the rank-ordered lists submitted by more than 22,000 applicants to a citywide lottery for more than 200 traditional and charter public schools in Washington, D.C. The results confirm previously reported findings that commuting distance, school demographics, and academic indicators play important…

  7. Job-housing imbalance and commuting of coastal industrial town in Liaoning province, China

    Science.gov (United States)

    Chen, Fei; Lu, Wei; Cai, Jun; Yang, Qiyao

    2017-11-01

    During the Twelve Five period, China promulgated industrial policies promote the energy-intensive industries relocate to coastal areas in order to utilize marine shipping resources. Consequently, some major state-owned steel and petrochemical enterprises have relocated and resulted in a large scale coastal area development. Restricted by the port construction, most of the coastal industrial areas are located in the outer suburbs. To balance between employment and housing, new industrial coastal towns were constructed. In this paper, we adopt a case-study approach to analysis some typical industrial coastal towns of Liaoning Province situated in the Bohai Bay, which is currently under rapid economic growth. Our investigations reflect the common phenomenon of long distance commuting and massive amount of vacant residences. More specifically, large plant relocation caused hundreds of kilometers of daily commute and enterprises had to provide housing subsidies and education incentives to motivate employees to relocate to coastal areas. Nonetheless, many employees still refuse to relocate due to job stability, diverse needs of family members and access to convenient services. These employees averaged 4 hours of commute daily and some who lived further had to reside in temporary industrial housing units and subject to long-term family separation. As a result, only a small portion of employees purchase new coastal residences but mostly for investment and retirement purposes, leading to massive vacancy and ghost-town phenomenon. In contrast to the low demand, coastal areas tend to develop large amount of residences prior to industrial relocation, which may be directly related to local government finances. Some local governments have sold residential land to developers to general revenue to support the subsequent industrial development. Subject to the strong preference of ocean- view, residential housing developers tend to select coast-line land to construct new residential

  8. Angelina's choice.

    Science.gov (United States)

    Goel, Nishu Singh

    2013-10-01

    This is an opinion piece on how a celebrity's personal choice to undergo prophylactic mastectomy on discovery of an aberrant gene, when publicly promoted, carries in itself the power to influence and impact healthcare trends and decisions. When celebrities advocate causes that are universally and uniformly acceptable and indisputable as the best in the realm of healthcare and cure (e.g. no smoking), it creates well-being and awareness in society at large. But those which are personal choices made out of a repertoire of other available and effective options may, because of celebrity preference, don the mantle of a norm. They thus run the danger of being blindly replicated by others without proper awareness and knowledge of the true potential of disease, risk factors, and other existing remedial or risk-reducing measures. Society should thus be encouraged to question, debate, and understand the validity, authenticity, and reason of the choices, especially those with a medical basis. This tempering of information with intelligence and rationale and making informed choices based on facts will serve humanity as a whole.

  9. Characterising food environment exposure at home, at work, and along commuting journeys using data on adults in the UK.

    Science.gov (United States)

    Burgoine, Thomas; Monsivais, Pablo

    2013-06-27

    Socio-ecological models of behaviour suggest that dietary behaviours are potentially shaped by exposure to the food environment ('foodscape'). Research on associations between the foodscape and diet and health has largely focussed on foodscapes around the home, despite recognition that non-home environments are likely to be important in a more complete assessment of foodscape exposure. This paper characterises and describes foodscape exposure of different types, at home, at work, and along commuting routes for a sample of working adults in Cambridgeshire, UK. Home and work locations, and transport habits for 2,696 adults aged 29-60 were drawn from the Fenland Study, UK. Food outlet locations were obtained from local councils and classified by type - we focus on convenience stores, restaurants, supermarkets and takeaway food outlets. Density of and proximity to food outlets was characterised at home and work. Commuting routes were modelled based on the shortest street network distance between home and work, with exposure (counts of food outlets) that accounted for travel mode and frequency. We describe these three domains of food environment exposure using descriptive and inferential statistics. For all types of food outlet, we found very different foodscapes around homes and workplaces (with overall outlet exposure at work 125% higher), as well as a potentially substantial exposure contribution from commuting routes. On average, work and commuting environments each contributed to foodscape exposure at least equally to residential neighbourhoods, which only accounted for roughly 30% of total exposure. Furthermore, for participants with highest overall exposure to takeaway food outlets, workplaces accounted for most of the exposure. Levels of relative exposure between home, work and commuting environments were poorly correlated. Relying solely on residential neighbourhood characterisation greatly underestimated total foodscape exposure in this sample, with levels of

  10. Commuters and traffic information : A revealed preference study on route choice behavior

    NARCIS (Netherlands)

    Moraes Ramos, G.; Frejinger, E.; Daamen, W.; Hoogendoorn, S.P.

    2012-01-01

    The past decades have seen an increased interest in the role of information to alleviate congestion. The relationship between travelers’ behavior and information, however, is not clear yet and the need of more experiments has been claimed in the literature. From May 9th, 2011 to July 12th, 2011 a

  11. Women's Perspectives on Retention in Higher Education in Jordan: Commute and Choice

    Science.gov (United States)

    Allaf, Carine

    2013-01-01

    Jordan is viewed as a country of social, political, and economic and advancement. It currently leads the region in literacy rates and is well on its way to achieving gender equity. However, some reports claim that Jordan maintains the widest gender gap in higher education completion in the region while others report that the percentage of females…

  12. Value of travel-time reliability : commuters' route-choice behavior in the Twin Cities.

    Science.gov (United States)

    2011-10-01

    Travel-time variability is a noteworthy factor in network performance. It measures the temporal uncertainty experienced by users in their : movement between any two nodes in a network. The importance of the time variance depends on the penalties incu...

  13. Associations between active commuting and physical activity in working adults: Cross-sectional results from the Commuting and Health in Cambridge study

    Science.gov (United States)

    Yang, Lin; Panter, Jenna; Griffin, Simon J.; Ogilvie, David

    2012-01-01

    Objective To quantify the association between time spent in active commuting and in moderate to vigorous physical activity (MVPA) in a sample of working adults living in both urban and rural locations. Methods In 2009, participants in the Commuting and Health in Cambridge study were sent questionnaires enquiring about sociodemographic characteristics and weekly time spent in active commuting. They were also invited to wear an accelerometer for seven days. Accelerometer data were used to compute the time spent in MVPA. Multiple regression models were used to examine the association between time spent in active commuting and MVPA. Results 475 participants (70% female) provided valid data. On average, participants recorded 55 (SD: 23.02) minutes of MVPA per day. For women, reporting 150 or more minutes of active commuting per week was associated with an estimated 8.50 (95% CI: 1.75 to 51.26, p = 0.01) additional minutes of daily MVPA compared to those who reported no time in active commuting. No overall associations were found in men. Conclusions Promoting active commuting might be an important way of increasing levels of physical activity, particularly in women. Further research should assess whether increases in time spent in active commuting are associated with increases in physical activity. PMID:22964003

  14. Modelling the relation between income and commuting distance

    DEFF Research Database (Denmark)

    Carra, Giulia; Mulalic, Ismir; Fosgerau, Mogens

    2016-01-01

    We discuss the distribution of commuting distances and its relation to income. Using data from Denmark, the UK and the USA, we show that the commuting distance is (i) broadly distributed with a slow decaying tail that can be fitted by a power law with exponent γ ≈ 3 and (ii) an average growing...... slowly as a power law with an exponent less than one that depends on the country considered. The classical theory for job search is based on the idea that workers evaluate the wage of potential jobs as they arrive sequentially through time, and extending this model with space, we obtain predictions...... that are strongly contradicted by our empirical findings. We propose an alternative model that is based on the idea that workers evaluate potential jobs based on a quality aspect and that workers search for jobs sequentially across space. We also assume that the density of potential jobs depends on the skills...

  15. Structure of weakly periodic rings with potent extended commutators

    OpenAIRE

    Adil Yaqub

    2001-01-01

    A well-known theorem of Jacobson (1964, page 217) asserts that a ring R with the property that, for each x in R, there exists an integer n(x)>1 such that xn(x)=x is necessarily commutative. This theorem is generalized to the case of a weakly periodic ring R with a “sufficient” number of potent extended commutators. A ring R is called weakly periodic if every x in R can be written in the form x=a+b, where a is nilpotent and b is “potent” in the sense that bn(b)=b for some integer n(b)>1. It is...

  16. [Quantity of physical exercise expended during commuting by office workers residing in the Greater Tokyo area].

    Science.gov (United States)

    Nakano, Harumi; Inoue, Sakae

    2010-01-01

    We measured how much physical exercise of moderate-to-high intensity was performed daily during commuting times by office workers who reside in the Greater Tokyo Area and use a train for commuting. The physical activity was measured by a portable accelerometer, Omron HJA-350 IT, which records METs (Metabolic Equivalents) every minute. The data were downloaded to a personal computer for calculation of the exercise quantity in specified time intervals. Exercise (Ex) was defined as (METs> or =3) x hours. Male commuters using the train (n=74) were found to spend 70 +/- 30 and 103 +/- 47 minutes for morning and evening commuting, respectively. They expended 3.4 +/- 1.7 Ex in the commuting of both morning and evening. This exercise quantity amounts to 64% of the whole day Ex, which was 2.9 times the whole day Ex of car commuters (n=78). The daily walking activity of the train commuters, 9,305 +/- 2,651 steps, was 2.7 times that of the car commuters (3,490 +/- 1,406 steps). The mean total Ex expended by the train commuters over 5 weekdays was calculated to be 26.5 Ex, which exceeds the weekly 23 Ex recommended by Guideline on Physical Exercise for Good Health, 2006, Japanese Ministry of Health, Labour, and Welfare. Train commuting by office workers residing in the Greater Tokyo Area seems to contribute to their physical health.

  17. Active commuting of the inhabitants of Liberec city in low and high walkability areas

    Directory of Open Access Journals (Sweden)

    Lukáš Rubín

    2015-12-01

    Full Text Available Background: Active commuting in terms of everyday transport to school or work can have a significant effect on physical activity. Active commuting can be influenced by the environment, and examples from abroad show that current environmental changes tend mostly to promote passive forms of commuting. A similar situation of decreasing active commuting might be expected in the Czech Republic. However, little information has been published to date about the issue of active commuting among the inhabitants of our country. Objective: The main objective of the present study is to describe the active commuting patterns of the inhabitants of Liberec city in low and high walkability areas. Methods: A total of 23,621 economically active inhabitants or students of Liberec city aged 6-87 years (34.77 ± 14.39 participated in the study. The data about commuting were retrieved from the national Population and Housing Census of 2011. Geographic information systems were used to objectively analyze the built environment and to calculate the walkability index. Results: Active commuting to/from school or work is used by 17.41% of inhabitants. Active commuting is dominated by walking (16.60% as opposed to cycling (0.81%. Inhabitants who lived in high walkability areas were more likely to actively commute than those living in low walkability areas (OR = 1.54; 95% CI [1.41, 1.68]. Conclusions: This study confirmed the findings of international studies about the effect of the built environment on active commuting among Liberec inhabitants. Active commuters are often those living near or in the city center, which is characterized by high walkability. In Liberec city, walking as a means of active commuting significantly prevails over cycling. One of the reasons might be the diverse topography of the city and the insufficiently developed cycling network.

  18. Individual Public Transportation Accessibility is Positively Associated with Self-Reported Active Commuting.

    Science.gov (United States)

    Djurhuus, Sune; Hansen, Henning Sten; Aadahl, Mette; Glümer, Charlotte

    2014-01-01

    Active commuters have lower risk of chronic disease. Understanding which of the, to some extent, modifiable characteristics of public transportation that facilitate its use is thus important in a public health perspective. The aim of the study was to examine the association between individual public transportation accessibility and self-reported active commuting, and whether the associations varied with commute distance, age, and gender. Twenty-eight thousand nine hundred twenty-eight commuters in The Capital Region of Denmark reported self-reported time spent either walking or cycling to work or study each day and the distance to work or study. Data were obtained from the Danish National Health Survey collected in February to April 2010. Individual accessibility by public transportation was calculated using a multi-modal network in a GIS. Multilevel logistic regression was used to analyze the association between accessibility, expressed as access area, and being an active commuter. Public transport accessibility area based on all stops within walking and cycling distance was positively associated with being an active commuter. Distance to work, age, and gender modified the associations. Residing within 10 km commute distance and in areas of high accessibility was associated with being an active commuter and meeting the recommendations of physical activity. For the respondents above 29 years, individual public transportation accessibility was positively associated with being an active commuter. Women having high accessibility had significantly higher odds of being an active commuter compared to having a low accessibility. For men, the associations were insignificant. This study extends the knowledge about the driving forces of using public transportation for commuting by examining the individual public transportation accessibility. Findings suggest that transportation accessibility supports active commuting and planning of improved public transit accessibility

  19. Fully controlled 5-phase, 10-pulse, line commutated rectifier

    OpenAIRE

    Masoud, Mahmoud I.

    2015-01-01

    The development and production of multiphase machines either generators or motors, specially five-phase, offers improved performance compared to three-phase counterpart. Five phase generators could generate power in applications such as, but not limited to, wind power generation, electric vehicles, aerospace, and oil and gas. The five-phase generator output requires converter system such as ac–dc converters. In this paper, a fully controlled 10-pulse line commutated rectifier, suitable to be ...

  20. First Commuter Air Carrier Safety Symposium, January 16 - 17, 1980.

    Science.gov (United States)

    1980-01-01

    airlines. 18 I suppose an underlying question which provides the frame - work or the starting point for this symposium is: How safe are commuters? And...the volatility factor in commercial aviation and the cautions which must be exercised in making statistical judgments based on one-year time frames . In...that I am stil not satis- fied. There are too many delays. There is too much lethargy. There is too much time lag between the identification of safety

  1. A study on mobility improvement for intellectually disabled student commuters

    Directory of Open Access Journals (Sweden)

    Fumihiko Nakamura

    2017-07-01

    Overall, our findings suggested that to actually implement mobility support in school commuting environments in a way that will improve the mobility of intellectually disabled people requires not only the cooperation of schools, but also contributions from transport operators, road administrators, and traffic administrators. Because the contributions of these entities are essential, awareness-raising activities and a system for promoting common understanding among them are vital.

  2. Limit algebras of differential forms in non-commutative geometry

    Indian Academy of Sciences (India)

    The GNS-representation of ∞A defined by a d-dimensional non-commutative volume integral on a d+-summable K-cycle on A is realized as the representation induced by the left action of A on ∗A. This supplements the representation A on the space of forms discussed by Connes (Ch. VI.1, Prop. 5, p. 550 of [C]).

  3. A community intervention to prevent traffic accidents among bicycle commuters.

    Science.gov (United States)

    Bacchieri, Giancarlo; Barros, Aluísio J D; Santos, Janaína V dos; Gonçalves, Helen; Gigante, Denise P

    2010-10-01

    To evaluate an educational intervention designed to prevent traffic accidents among workers that use the bicycle for commuting. A longitudinal intervention study with a stepped wedge implementation was carried out between January 2006 and May 2007. Five neighborhoods with distinct geographic characteristics were selected in the city of Pelotas, Brazil, and 42 census tracts were randomly selected from these neighborhoods. All households were screened for male bicycle commuters, resulting in a sample of 1,133 individuals. The outcomes analyzed were "traffic accidents" and "near accidents". The cyclists were interviewed monthly by phone to record traffic accidents and "near accidents". Every 15 days, from the second month of study, a group of about 60 cyclists was invited to attend the intervention meeting that included an educational component (a talk and a video presentation), distribution of a safety kit (reflective belt & sash, reflective tape and an educational booklet) and a bicycle breaks check-up (maintenance performed if necessary). Poisson regression adjusted for time effect was used to assess the intervention effect. Nearly 45% of the cyclists did not attend the intervention. During the study period, 9% of the study individuals reported a traffic accident and 88% reported a "near accident". In total there were 106 accidents and 1,091 near accidents. There was no effect observed from the intervention on either of the outcomes. The intervention tested was not capable of reducing traffic accidents among bicycle commuters. Lack of interest in safety by commuters and external factors, such as road design and motorist behavior, may have together influenced this result.

  4. AC system stabilization via phase shift transformer with thyristor commutation

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Jose Carlos de; Guimaraes, Geraldo Caixeta; Moraes, Adelio Jose [Uberlandia Univ., MG (Brazil); Abreu, Jose Policarpo G. de [Escola Federal de Engenharia de Itajuba, MG (Brazil); Oliveira, Edimar Jose de [Juiz de Fora Univ., MG (Brazil)

    1994-12-31

    This article aims to present initially the constructive and operative forms of a phase-shift autotransformer which provides both magnitude and phase angle change through thyristor commutation, including a technic to reduce the number of thyristors. Following, it is proposed a control system to make such equipment an efficient AC system stabilizing tool. It is presented some simulation results to show the operation of this transformer in an electrical system. (author) 3 refs., 11 figs., 3 tabs.

  5. A norm inequality for pairs of commuting positive semidefinite matrices

    OpenAIRE

    Audenaert, Koenraad M. R.

    2014-01-01

    For $k=1,\\ldots,K$, let $A_k$ and $B_k$ be positive semidefinite matrices such that, for each $k$, $A_k$ commutes with $B_k$. We show that, for any unitarily invariant norm, \\[ |||\\sum_{k=1}^K A_kB_k||| \\le ||| (\\sum_{k=1}^K A_k)\\;(\\sum_{k=1}^K B_k)|||. \\

  6. Commutability of Cytomegalovirus WHO International Standard in Different Matrices.

    Science.gov (United States)

    Jones, Sara; Webb, Erika M; Barry, Catherine P; Choi, Won S; Abravaya, Klara B; Schneider, George J; Ho, Shiaolan Y

    2016-06-01

    Commutability of quantitative standards allows patient results to be compared across molecular diagnostic methods and laboratories. This is critical to establishing quantitative thresholds for use in clinical decision-making. A matrix effect associated with the 1st cytomegalovirus (CMV) WHO international standard (IS) was identified using the Abbott RealTime CMV assay. A commutability study was performed to compare the CMV WHO IS and patient specimens diluted in plasma and whole blood. Patient specimens showed similar CMV DNA quantitation values regardless of the diluent or extraction procedure used. The CMV WHO IS, on the other hand, exhibited a matrix effect. The CMV concentration reported for the WHO IS diluted in plasma was within the 95% prediction interval established with patient samples. In contrast, the reported DNA concentration of the CMV WHO IS diluted in whole blood was reduced approximately 0.4 log copies/ml, and values fell outside the 95% prediction interval. Calibrating the assay by using the CMV WHO IS diluted in whole blood would introduce a bias for CMV whole-blood quantitation; samples would be reported as having higher measured concentrations, by approximately 0.4 log IU/ml. Based on the commutability study with patient samples, the RealTime CMV assay was standardized based on the CMV WHO IS diluted in plasma. A revision of the instructions for use of the CMV WHO IS should be considered to alert users of the potential impact from the diluent matrix. The identification of a matrix effect with the CMV WHO IS underscores the importance of assessing commutability of the IS in order to achieve consistent results across methods. Copyright © 2016 Jones et al.

  7. A Subjective Rational Choice

    Science.gov (United States)

    Vinogradov, G. P.

    2017-01-01

    The problem of constructing a choice model of an agent with endogenous purposes of evolution is under debate. It is demonstrated that its solution requires the development of well-known methods of decision-making while taking into account the relation of action mode motivation to an agent’s ambition to implement subjectively understood interests and the environment state. The latter is submitted for consideration as a purposeful state situation model that exists only in the mind of an agent. It is the situation that is a basis for getting an insight into the agent’s ideas on the possible selected action mode results. The agent’s ambition to build his confidence in the feasibility of the action mode and the possibility of achieving the desired state requires him to use the procedures of forming an idea model based on the measured values of environment state. This leads to the gaming approach for the choice problem and its solution can be obtained on a set of trade-off alternatives.

  8. Modelling the relation between income and commuting distance.

    Science.gov (United States)

    Carra, Giulia; Mulalic, Ismir; Fosgerau, Mogens; Barthelemy, Marc

    2016-06-01

    We discuss the distribution of commuting distances and its relation to income. Using data from Denmark, the UK and the USA, we show that the commuting distance is (i) broadly distributed with a slow decaying tail that can be fitted by a power law with exponent γ ≈ 3 and (ii) an average growing slowly as a power law with an exponent less than one that depends on the country considered. The classical theory for job search is based on the idea that workers evaluate the wage of potential jobs as they arrive sequentially through time, and extending this model with space, we obtain predictions that are strongly contradicted by our empirical findings. We propose an alternative model that is based on the idea that workers evaluate potential jobs based on a quality aspect and that workers search for jobs sequentially across space. We also assume that the density of potential jobs depends on the skills of the worker and decreases with the wage. The predicted distribution of commuting distances decays as 1/r(3) and is independent of the distribution of the quality of jobs. We find our alternative model to be in agreement with our data. This type of approach opens new perspectives for the modelling of mobility. © 2016 The Author(s).

  9. Non-topological non-commutativity in string theory

    Energy Technology Data Exchange (ETDEWEB)

    Guttenberg, S. [NCSR Demokritos, INP, Patriarchou Gregoriou and Neapoleos Str., 15310 Agia Paraskevi Attikis (Greece); Herbst, M. [CERN, 1211 Geneva 23 (Switzerland); Kreuzer, M. [Institute for Theoretical Physics, TU Wien, Wiedner Hauptstr. 8-10, 1040 Vienna (Austria); Rashkov, R. [Erwin Schroedinger Institute for Mathematical Physics, Boltzmanngasse 9, 1090 Vienna (Austria)

    2008-04-15

    Quantization of coordinates leads to the non-commutative product of deformation quantization, but is also at the roots of string theory, for which space-time coordinates become the dynamical fields of a two-dimensional conformal quantum field theory. Appositely, open string diagrams provided the inspiration for Kontsevich's solution of the long-standing problem of quantization of Poisson geometry by virtue of his formality theorem. In the context of D-brane physics non-commutativity is not limited, however, to the topological sector. We show that non-commutative effective actions still make sense when associativity is lost and establish a generalized Connes-Flato-Sternheimer condition through second order in a derivative expansion. The measure in general curved backgrounds is naturally provided by the Born-Infeld action and reduces to the symplectic measure in the topological limit, but remains non-singular even for degenerate Poisson structures. Analogous superspace deformations by RR-fields are also discussed. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  10. A New Approach of Minimizing Commutation Torque Ripple for BLDCM

    Directory of Open Access Journals (Sweden)

    Bo Tan

    2017-10-01

    Full Text Available The properties of brushless DC motor (BLDCM are similar to the fractional, slot-concentrated winding of permanent-magnet synchronous machines, and they fit well for electric vehicle application. However, BLDCM still suffers from the high commutation torque ripple in the case of the traditional square-wave current control (SWC method, where the current vector rotates asynchronously with back-EMF. A current optimizing control (COC method for BLDCM is proposed in the paper to minimize the commutation torque ripple. The trajectories of the three phase currents are planned by the given torque and the optimized result of the copper loss and motor torque equations. The properties of COC are analyzed and compared with that of SWC in the stationary reference frame. The results show that the way of making the current vector rotate synchronously with back-EMF (back-Electromotive Force can minimize the modulus and velocity of the current vector in the commutation region, and reduce the torque ripple. Experimental tests obtained from an 82 W BLDCM are done to confirm the theoretical findings.

  11. Dissimilarity for functional data clustering based on smoothing parameter commutation.

    Science.gov (United States)

    Tzeng, ShengLi; Hennig, Christian; Li, Yu-Fen; Lin, Chien-Ju

    2017-01-01

    Many studies measure the same type of information longitudinally on the same subject at multiple time points, and clustering of such functional data has many important applications. We propose a novel and easy method to implement dissimilarity measure for functional data clustering based on smoothing splines and smoothing parameter commutation. This method handles data observed at regular or irregular time points in the same way. We measure the dissimilarity between subjects based on varying curve estimates with pairwise commutation of smoothing parameters. The intuition is that smoothing parameters of smoothing splines reflect the inverse of the signal-to-noise ratios and that when applying an identical smoothing parameter the smoothed curves for two similar subjects are expected to be close. Our method takes into account the estimation uncertainty using smoothing parameter commutation and is not strongly affected by outliers. It can also be used for outlier detection. The effectiveness of our proposal is shown by simulations comparing it to other dissimilarity measures and by a real application to methadone dosage maintenance levels.

  12. On monomial commutativity of operators satisfying commutation relations and periodic points for one-dimensional dynamical systems

    Science.gov (United States)

    Tumwesigye, Alex Behakanira; Silvestrov, Sergei

    2014-12-01

    T. Persson and S. D. Sivestrov investigated representations of operators satisfying the relation XX* = F(X*X) in connection with periodic points and orbits of the map F. In particular they derived commutativity conditions for two monomials in operators A and B on a Hilbert space, satisfying the relation AB = BF(A). In this article, we shall apply their results to special one-dimensional dynamical systems and and give an explicit description of the interplay between periodic orbits of one-dimensional piecewise polynomial maps and commutativity of monomials for special operators A and B. Furthermore, we shall apply our results to derive conditions on β for the special case when Fβ is the β-shift dynamical system.

  13. School Choice

    Directory of Open Access Journals (Sweden)

    Gene V Glass

    1994-02-01

    Full Text Available Eighteen educators and scholars discuss vouchers as a means of promoting school choice and introducing competition into education. The discussion centers around the thinking of the economist Herbert Gintis, who participated in the discussion, and his notion of market socialism as it might apply to education. In 1976, Gintis published, with Samuel Bowles, Schooling in Capitalist America; in 1994, he is arguing for competitive markets for the delivery of schooling.

  14. Hybrid generalized Bosbach and Rie c̆ an states on non-commutative residuated lattices

    Science.gov (United States)

    Ma, Zhen Ming; Yang, Wei

    2016-08-01

    Generalized Bosbach and Rie c̆ an states, which are useful for the development of an algebraic theory of probabilistic models for commutative or non-commutative fuzzy logics, have been investigated in the literature. In this paper, a new way arising from generalizing residuated lattice-based filters from commutative case to non-commutative one is applied to introduce new notions of generalized Bosbach and Rie c̆ an states, which are called hybrid ones, on non-commutative residuated lattices is provided, and the relationships between hybrid generalized states and those existing ones are studied, examples show that they are different. In particular, two problems from L.C. Ciungu, G. Georgescu, and C. Mure, "Generalized Bosbach States: Part I" (Archive for Mathematical Logic 52 (2013):335-376) are solved, and properties of hybrid generalized states, which are similar to those on commutative residuated lattices, are obtained without the condition "strong".

  15. Individual Public Transportation Accessibility is Positively Associated with Self-Reported Active Commuting

    OpenAIRE

    Djurhuus, Sune; Hansen, Henning Sten; Aadahl, Mette; Glümer, Charlotte

    2014-01-01

    Background: Active commuters have lower risk of chronic disease. Understanding which of the, to some extent, modifiable characteristics of public transportation that facilitate its use is thus important in a public health perspective. The aim of the study was to examine the association between individual public transportation accessibility and self-reported active commuting, and whether the associations varied with commute distance, age, and gender. Methods: Twenty-eight thousand nine hund...

  16. Individual public transportation accessibility is positively associated with self-reported active commuting

    Directory of Open Access Journals (Sweden)

    Sune eDjurhuus

    2014-11-01

    Full Text Available Background: Active commuters have lower risk of chronic disease. Understanding which of the, to some extent, modifiable characteristics of public transportation that facilitate its use is thus important in a public health perspective. The aim of the study was to examine the association between individual public transportation accessibility and self-reported active commuting, and whether the associations varied with commute distance, age and gender. Methods: 28,928 commuters in the Capital Region of Denmark reported self-reported time spent either walking or cycling to work or study each day and the distance to work or study. Data were obtained from the Danish National Health Survey collected in February to April 2010. Individual accessibility by public transportation was calculated using a multimodal network in a GIS. Multilevel logistic regression was used to analyze the association between accessibility, expressed as access area, and being an active commuter.Results: Public transport accessibility area based on all stops within walking and cycling distance was positively associated with being an active commuter. Distance to work, age and gender modified the associations. Residing within 10 km commuting distance and in areas of high accessibility was associated with being an active commuter and meeting the recommendations of physical activity. For the respondents above 29 years, Individual public transportation accessibility was positively associated with being an active commuter. Women having high accessibility had significantly higher odds of being an active commuter compared to having a low accessibility. For men the associations were insignificant.Conclusions: This study extends the knowledge about the driving forces of using public transportation for commuting by examining the individual public transportation accessibility. Findings suggest that transportation accessibility supports active commuting and planning of improved public transit

  17. Railway-controller-perceived mental work load, cognitive failure and risky commuting.

    Science.gov (United States)

    Elfering, Achim; Grebner, Simone; Haller, Martina

    2012-01-01

    This questionnaire study tests cognitive failures as a mediator of the potential influence of mental work demands and conscientiousness on risky commuting. Participants were 104 railway-controllers (19% female). Failure of memory, attention regulation and action execution were assessed with the Workplace Cognitive Failure (WCF) scale. Mental work demands were measured by the Instrument for Stress-Oriented Task Analysis (ISTA). A structural equation model testing WCF as the mediator of (1) the relationship between mental work demands and risky commuting (p < 0.05) and (2) the link between conscientiousness and risky commuting (p < 0.05) fitted well with empirical data. In railway-controllers frequent interruptions, time pressure, and high concentration demands are likely to increase cognitive load and thereby boost WCF during work and also during commuting, thereby reducing commuting safety. The results underline the need for work redesign to improve commuting safety. Commuting accidents occur frequently and at high cost. This study shows that mental work demands of railway staff are related to cognitive failure and risky commuting behaviour such as failing to give way and overlooking stop signs. Primary prevention of commuting accidents should include reduction of mental workload.

  18. Potential health impact of switching from car to public transportation when commuting to work.

    Science.gov (United States)

    Morabia, Alfredo; Mirer, Franklin E; Amstislavski, Tashia M; Eisl, Holger M; Werbe-Fuentes, Jordan; Gorczynski, John; Goranson, Chris; Wolff, Mary S; Markowitz, Steven B

    2010-12-01

    We assessed humidity-corrected particulate matter (PM(2.5)) exposure and physical activity (using global positioning system monitors and diaries) among 18 people who commuted by car to Queens College, New York, New York, for 5 days, and then switched to commuting for the next 5 days via public transportation. The PM(2.5) differed little between car and public transportation commutes (1.41 μg/M(3)·min; P = .226). Commuting by public transportation rather than by car increased energy expenditure (+124 kcal/day; P < .001) equivalent to the loss of 1 pound of body fat per 6 weeks.

  19. Non-commutative gauge gravity: second-order correction and scalar particle creation

    Energy Technology Data Exchange (ETDEWEB)

    Zaim, Slimane [Departement de Physique, Faculte des Sciences, Universite de Batna (Algeria); Khodja, Lamine, E-mail: zaimslimane@yahoo.f [Departement de Physique, Faculte des Sciences Exactes, Universite Mentouri, Constantine (Algeria)

    2010-05-01

    We construct a non-commutative gauge theory for a charged scalar field and verify its invariance under local Poincare and general coordinate transformations. We derive a general Klein-Gordon equation up to the second order of the non-commutativity parameter using the general modified field equation. As an application, we choose the Bianchi I universe and use the Seiberg-Witten maps to obtain the deformed non-commutative metric and study a particle production process. We show that non-commutativity plays the same role as an electric field, gravity and chemical potential.

  20. Estimating spatial accessibility to facilities on the regional scale: an extended commuting-based interaction potential model

    Directory of Open Access Journals (Sweden)

    Charreire Hélène

    2011-01-01

    Full Text Available Abstract Background There is growing interest in the study of the relationships between individual health-related behaviours (e.g. food intake and physical activity and measurements of spatial accessibility to the associated facilities (e.g. food outlets and sport facilities. The aim of this study is to propose measurements of spatial accessibility to facilities on the regional scale, using aggregated data. We first used a potential accessibility model that partly makes it possible to overcome the limitations of the most frequently used indices such as the count of opportunities within a given neighbourhood. We then propose an extended model in order to take into account both home and work-based accessibility for a commuting population. Results Potential accessibility estimation provides a very different picture of the accessibility levels experienced by the population than the more classical "number of opportunities per census tract" index. The extended model for commuters increases the overall accessibility levels but this increase differs according to the urbanisation level. Strongest increases are observed in some rural municipalities with initial low accessibility levels. Distance to major urban poles seems to play an essential role. Conclusions Accessibility is a multi-dimensional concept that should integrate some aspects of travel behaviour. Our work supports the evidence that the choice of appropriate accessibility indices including both residential and non-residential environmental features is necessary. Such models have potential implications for providing relevant information to policy-makers in the field of public health.

  1. Intrinsic localized modes and nonlinear impurity modes in curved ...

    Indian Academy of Sciences (India)

    We explore the nature of intrinsic localized modes (ILMs) in a curved Fermi–. Pasta–Ulam (FPU) chain ... We further demonstrate that a nonlinear impurity mode may be treated as a bound state of an ILM with the impurity .... length [14] and see that the particular choice of the chain geometry ensures the DB propagation with ...

  2. Commutability of control materials for external quality assessment of serum apolipoprotein A-I measurement.

    Science.gov (United States)

    Zeng, Jie; Qi, Tianqi; Wang, Shu; Zhang, Tianjiao; Zhou, Weiyan; Zhao, Haijian; Ma, Rong; Zhang, Jiangtao; Yan, Ying; Dong, Jun; Zhang, Chuanbao; Chen, Wenxiang

    2017-12-01

    The aim of the current study was to evaluate the commutability of commercial control materials and human serum pools and to investigate the suitability of the materials for the external quality assessment (EQA) of serum apolipoprotein A-I (apo A-I) measurement. The Clinical and Laboratory Standards Institute (CLSI) EP14-A3 protocol was used for the commutability study. Apo A-I concentrations in two levels of commercial control materials used in EQA program, two fresh-frozen human serum pools (FSPs) and two frozen human serum pools prepared from residual clinical specimens (RSPs) were measured along with 50 individual samples using nine commercial assays. Measurement results of the 50 individual samples obtained with different assays were pairwise analyzed by Deming regression, and 95% prediction intervals (PIs) were calculated. The commutability of the processed materials was evaluated by comparing the measurement results of the materials with the limits of the PIs. The FSP-1 was commutable for all the 36 assay pairs, and FSP-2 was commutable for 30 pairs; RSP-1 and RSP-2 showed commutability for 27/36 and 22/36 assay pairs, respectively, whereas the two EQA materials were commutable only for 4/36 and 5/36 assay pairs, respectively. Non-commutability of the tested EQA materials has been observed among current apo A-I assays. EQA programs need either to take into account the commutability-related biases in the interpretation of the EQA results or to use more commutable materials. Frozen human serum pools were commutable for most of the assays.

  3. The poset of the nilpotent commutator of a nilpotent matrix

    OpenAIRE

    Khatami, Leila

    2012-01-01

    Let $B$ be an $n \\times n$ nilpotent matrix with entries in an infinite field $\\k$. Assume that $B$ is in Jordan canonical form with the associated Jordan block partition $P$. In this paper, we study a poset $\\mathcal{D}_P$ associated to the nilpotent commutator of $B$ and a certain partition of $n$, denoted by $\\lambda_U(P)$, defined in terms of the lengths of unions of special chains in $\\mathcal{D}_P$. Polona Oblak associated to a given partition $P$ another partition $Ob(P)$ resulting fro...

  4. Revisiting quantum mechanics on non-commutative space-time

    Science.gov (United States)

    Nandi, Partha; Pal, Sayan Kumar; Bose, Aritra N.; Chakraborty, Biswajit

    2017-11-01

    We construct an effective commutative Schrödinger equation in Moyal space-time in (1 + 1) -dimension where both t and x are operator-valued and satisfy [ t ˆ , x ˆ ] = iθ. Beginning with a time-reparametrised invariant form of an action we identify the actions of various space-time coordinates and their conjugate momenta on quantum states, represented by Hilbert-Schmidt operators. Since time is also regarded as a configuration space variable, we show how an 'induced' inner product can be extracted, so that an appropriate probabilistic interpretation is obtained. We then discuss several other applications of the formalism developed so far.

  5. Note on the Tableau Technique for Commutative Transition Systems

    DEFF Research Database (Denmark)

    Srba, Jirí

    2002-01-01

    We define a class of transition systems called effective commutative transition systems (ECTS) and show, by generalising a tableau-based proof for BPP, that strong bisimilarity between any two states of such a transition system is decidable. It gives a general technique for extending decidability...... borders of strong bisimilarity for a wide class of infinite-state transition systems. This is demonstrated for several process formalisms, namely BPP process algebra, lossy BPP processes, BPP systems with interrupt and timed-arc BPP nets....

  6. Supergravity and Light-Like Non-commutativity

    CERN Document Server

    Alishahiha, M; Russo, Jorge G; Alishahiha, Mohsen; Oz, Yaron; Russo, Jorge G.

    2000-01-01

    We construct dual supergravity descriptions of field theories and little string theories with light-like non-commutativity. The field theories are realized on the world-volume of Dp branes with light-like NS $B$ field and M5 branes with light-like $C$ field. The little string theories are realized on the world-volume of NS5 branes with light-like RR $A$ fields. The supergravity backgrounds are closely related to the $A=0,B=0,C=0$ backgrounds. We discuss the implications of these results. We also construct dual supergravity descriptions of ODp theories realized on the worldvolume of NS5 branes with RR backgrounds.

  7. Choice & Consequence

    DEFF Research Database (Denmark)

    Khan, Azam

    To move toward environmental sustainability, we propose that a computational approach may be needed due to the complexity of resource production and consumption. While digital sensors and predictive simulation has the potential to help us to minimize resource consumption, the indirect relation...... between cause and effect in complex systems complicates decision making. To address this issue, we examine the central role that data-driven decision making could play in critical domains such as sustainability or medical treatment. We developed systems for exploratory data analysis and data visualization...... of data analysis and instructional interface design, to both simulation systems and decision support interfaces. We hope that projects such as these will help people to understand the link between their choices and the consequences of their decisions....

  8. Market Signals: Evidence on the Determinants and Consequences of School Choice from a Citywide Lottery. Working Paper 45

    Science.gov (United States)

    Glazerman, Steve; Dotter, Dallas

    2016-01-01

    We estimate school-choice preferences revealed by the rank-ordered lists submitted by more than 22,000 applicants to a citywide lottery for more than 200 traditional and charter public schools in Washington, DC. The results confirm previously reported findings that commuting distance, school demographics, and academic indicators play important…

  9. Multiple Weighted Estimates for Vector-Valued Multilinear Singular Integrals with Non-Smooth Kernels and Its Commutators

    Directory of Open Access Journals (Sweden)

    Dongxiang Chen

    2013-01-01

    commutator and iterated commutator generated by the vector-valued multilinear operator and BMO functions. By the weighted estimates for a class of new variant maximal and sharp maximal functions, the multiple weighted norm inequalities for such operators are obtained.

  10. 49 CFR 37.51 - Key stations in commuter rail systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Key stations in commuter rail systems. 37.51... INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities § 37.51 Key stations in commuter rail systems... boardings exceed average station passenger boardings on the rail system by at least fifteen percent, unless...

  11. Modeling commuter preferences for the proposed bus rapid transit in Dar-es-Salaam

    NARCIS (Netherlands)

    Nkurunziza, A.; Zuidgeest, M.H.P.; Brussel, M.J.G.; van Maarseveen, M.F.A.M.

    2012-01-01

    The paper analyzes individual commuter preferences towards the proposed bus rapid transit (BRT) system in Dar-es-Salaam, Tanzania. The objective of the survey was to identify how commuters perceive and value the proposed BRT service quality attributes. A stated preference survey of potential users

  12. Getting to High School in Baltimore: Student Commuting and Public Transportation

    Science.gov (United States)

    Stein, Marc L.; Grigg, Jeffrey; Cronister, Curt; Chavis, Celeste; Connolly, Faith

    2017-01-01

    This report is the first publication of a multi-year project examining the relationship between student commutes using public transportation and on-time arrival and absenteeism. This report begins to develop a basic understanding of how students commute to high school in Baltimore with a focus on those using public transportation. The report is…

  13. New PWM method and commutation strategy for HF-link converters for fuel cells and photovoltaics

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a new PWM method and commutation strategy for HF-link converters, which leads to safe commutation of the load current in the output bidirectional bridge. The proposed implementation is independent of the particular HF-link converter topology and bidirectional switch selection ...

  14. A Comparison of Single Freshmen Resident and Commuter Students Perceptions of the Junior College Environment.

    Science.gov (United States)

    Markee, David J.

    The environmental perceptions of 144 randomly selected freshman students at a southwestern junior college were measured using the College and University Environment Scales (CUES). The sample was equally divided between male and female students, and among three groups: city commuters, rural commuters, and campus residents. Differences between group…

  15. The effect of perceived mobility necessity in the choice of departure time

    DEFF Research Database (Denmark)

    Thorhauge, Mikkel; Cherchi, Elisabetta; Rich, Jeppe

    2014-01-01

    is likely to affect the choice of departure time. However departure time choice is also related to the full daily activity pattern, such as a restriction or a preference in one activity may form restrictions in the flexibility of other activities and thereby affect the preference for the related departure......Departure time choice plays a crucial role in addressing the problem of urban congestion. Since the work of Small (1982), many studies have shown that travelers trade-off between travel time and scheduling delay and that travel time variability also plays an important role because uncertainty...... time. In this paper we investigate how the latent effect of the perceived mobility necessities affects the choice of departure time. A stated choice experiment collected among workers who commute to Copenhagen center is used to estimate 9 hybrid choice models where the discrete choice of departing...

  16. Non-commutative multiple-valued logic algebras

    CERN Document Server

    Ciungu, Lavinia Corina

    2014-01-01

    This monograph provides a self-contained and easy-to-read introduction to non-commutative multiple-valued logic algebras; a subject which has attracted much interest in the past few years because of its impact on information science, artificial intelligence and other subjects.   A study of the newest results in the field, the monograph includes treatment of pseudo-BCK algebras, pseudo-hoops, residuated lattices, bounded divisible residuated lattices, pseudo-MTL algebras, pseudo-BL algebras and pseudo-MV algebras. It provides a fresh perspective on new trends in logic and algebras in that algebraic structures can be developed into fuzzy logics which connect quantum mechanics, mathematical logic, probability theory, algebra and soft computing.   Written in a clear, concise and direct manner, Non-Commutative Multiple-Valued Logic Algebras will be of interest to masters and PhD students, as well as researchers in mathematical logic and theoretical computer science.

  17. Commuting nonselfadjoint operators in Hilbert space two independent studies

    CERN Document Server

    Livšic, Moshe S

    1987-01-01

    Classification of commuting non-selfadjoint operators is one of the most challenging problems in operator theory even in the finite-dimensional case. The spectral analysis of dissipative operators has led to a series of deep results in the framework of unitary dilations and characteristic operator functions. It has turned out that the theory has to be based on analytic functions on algebraic manifolds and not on functions of several independent variables as was previously believed. This follows from the generalized Cayley-Hamilton Theorem, due to M.S.Livsic: "Two commuting operators with finite dimensional imaginary parts are connected in the generic case, by a certain algebraic equation whose degree does not exceed the dimension of the sum of the ranges of imaginary parts." Such investigations have been carried out in two directions. One of them, presented by L.L.Waksman, is related to semigroups of projections of multiplication operators on Riemann surfaces. Another direction, which is presented here by M.S...

  18. Breakfast Skipping, Extreme Commutes, and the Sex Composition at Birth.

    Science.gov (United States)

    Mazumder, Bhashkar; Seeskin, Zachary

    2015-01-01

    A growing body of literature has shown that environmental exposures in the period around conception can affect the sex ratio at birth through selective attrition that favors the survival of female conceptuses. Glucose availability is considered a key indicator of the fetal environment, and its absence as a result of meal skipping may inhibit male survival. We hypothesize that breakfast skipping during pregnancy may lead to a reduction in the fraction of male births. Using time use data from the United States we show that women with commute times of 90 minutes or longer are 20 percentage points more likely to skip breakfast. Using U.S. census data we show that women with commute times of 90 minutes or longer are 1.2 percentage points less likely to have a male child under the age of 2. Under some assumptions, this implies that routinely skipping breakfast around the time of conception leads to a 6 percentage point reduction in the probability of a male child. Skipping breakfast during pregnancy may therefore constitute a poor environment for fetal health more generally.

  19. Urban routes and commuting bicyclist’s aesthetic experience

    Directory of Open Access Journals (Sweden)

    Harpa Stefansdottir

    2014-08-01

    Full Text Available The present study examines whether and in what way aesthetic experience is involved in the judged quality of bicyclist’s route which they have chosen to ride between home and work. In this respect it is considered important to distinguish aesthetic experience from experience that is related to the influence of instrumental or functional features. The aesthetic impact is primarily related to features that stimulate emotional well-being when cycling. An online survey was conducted in three Nordic cities, Odense, Trondheim and Reykjavík, concentrating on cycling in different urban surroundings. The interpretation of the meanings and values associated with certain features or characteristics that influenced the commuting cyclists’ aesthetic experience is in this paper based on three theoretical viewpoints: (1 the phenomenology of perception and experience, (2 urban design theory and (3 environmental aesthetic theories and methods. The last theory involves the interpretation of experience from the environment into aesthetic meaning. The results of the survey indicate that aesthetic experience is of value to most of the respondents and is, therefore, of importance in developing the quality of bicycle routes for commuting. Greenery and contact with the natural environment and distance from motorised traffic are the most important influences on pleasurable aesthetic experience.

  20. Tensors, !-graphs, and non-commutative quantum structures

    Directory of Open Access Journals (Sweden)

    Aleks Kissinger

    2014-12-01

    Full Text Available Categorical quantum mechanics (CQM and the theory of quantum groups rely heavily on the use of structures that have both an algebraic and co-algebraic component, making them well-suited for manipulation using diagrammatic techniques. Diagrams allow us to easily form complex compositions of (coalgebraic structures, and prove their equality via graph rewriting. One of the biggest challenges in going beyond simple rewriting-based proofs is designing a graphical language that is expressive enough to prove interesting properties (e.g. normal form results about not just single diagrams, but entire families of diagrams. One candidate is the language of !-graphs, which consist of graphs with certain subgraphs marked with boxes (called !-boxes that can be repeated any number of times. New !-graph equations can then be proved using a powerful technique called !-box induction. However, previously this technique only applied to commutative (or cocommutative algebraic structures, severely limiting its applications in some parts of CQM and (especially quantum groups. In this paper, we fix this shortcoming by offering a new semantics for non-commutative !-graphs using an enriched version of Penrose's abstract tensor notation.

  1. Novel theory of the human brain: information-commutation basis of architecture and principles of operation

    Directory of Open Access Journals (Sweden)

    Bryukhovetskiy AS

    2015-02-01

    Full Text Available Andrey S Bryukhovetskiy Center for Biomedical Technologies, Federal Research and Clinical Center for Specialized Types of Medical Assistance and Medical Technologies of the Federal Medical Biological Agency, NeuroVita Clinic of Interventional and Restorative Neurology and Therapy, Moscow, Russia Abstract: Based on the methodology of the informational approach and research of the genome, proteome, and complete transcriptome profiles of different cells in the nervous tissue of the human brain, the author proposes a new theory of information-commutation organization and architecture of the human brain which is an alternative to the conventional systemic connective morphofunctional paradigm of the brain framework. Informational principles of brain operation are defined: the modular principle, holographic principle, principle of systematicity of vertical commutative connection and complexity of horizontal commutative connection, regulatory principle, relay principle, modulation principle, “illumination” principle, principle of personalized memory and intellect, and principle of low energy consumption. The author demonstrates that the cortex functions only as a switchboard and router of information, while information is processed outside the nervous tissue of the brain in the intermeningeal space. The main structural element of information-commutation in the brain is not the neuron, but information-commutation modules that are subdivided into receiver modules, transmitter modules, and subscriber modules, forming a vertical architecture of nervous tissue in the brain as information lines and information channels, and a horizontal architecture as central, intermediate, and peripheral information-commutation platforms. Information in information-commutation modules is transferred by means of the carriers that are characteristic to the specific information level from inductome to genome, transcriptome, proteome, metabolome, secretome, and magnetome

  2. Conference on Recent Advances in Commutative Ring and Module Theory & Conference on Rings and Polynomials

    CERN Document Server

    Frisch, Sophie; Glaz, Sarah; Tartarone, Francesca; Zanardo, Paolo

    2017-01-01

    This volume presents a collection of articles highlighting recent developments in commutative algebra and related non-commutative generalizations. It also includes an extensive bibliography and lists a substantial number of open problems that point to future directions of research in the represented subfields. The contributions cover areas in commutative algebra that have flourished in the last few decades and are not yet well represented in book form. Highlighted topics and research methods include Noetherian and non-Noetherian ring theory, module theory and integer-valued polynomials along with connections to algebraic number theory, algebraic geometry, topology and homological algebra. Most of the eighteen contributions are authored by attendees of the two conferences in commutative algebra that were held in the summer of 2016: “Recent Advances in Commutative Ring and Module Theory,” Bressanone, Italy; “Conference on Rings and Polynomials”  Graz, Austria. There is also a small collection of invite...

  3. Methods and apparatus using commutative error detection values for fault isolation in multiple node computers

    Science.gov (United States)

    Almasi, Gheorghe [Ardsley, NY; Blumrich, Matthias Augustin [Ridgefield, CT; Chen, Dong [Croton-On-Hudson, NY; Coteus, Paul [Yorktown, NY; Gara, Alan [Mount Kisco, NY; Giampapa, Mark E [Irvington, NY; Heidelberger, Philip [Cortlandt Manor, NY; Hoenicke, Dirk I [Ossining, NY; Singh, Sarabjeet [Mississauga, CA; Steinmacher-Burow, Burkhard D [Wernau, DE; Takken, Todd [Brewster, NY; Vranas, Pavlos [Bedford Hills, NY

    2008-06-03

    Methods and apparatus perform fault isolation in multiple node computing systems using commutative error detection values for--example, checksums--to identify and to isolate faulty nodes. When information associated with a reproducible portion of a computer program is injected into a network by a node, a commutative error detection value is calculated. At intervals, node fault detection apparatus associated with the multiple node computer system retrieve commutative error detection values associated with the node and stores them in memory. When the computer program is executed again by the multiple node computer system, new commutative error detection values are created and stored in memory. The node fault detection apparatus identifies faulty nodes by comparing commutative error detection values associated with reproducible portions of the application program generated by a particular node from different runs of the application program. Differences in values indicate a possible faulty node.

  4. Individual public transportation accessibility is positively associated with self-reported active commuting

    DEFF Research Database (Denmark)

    Djurhuus, Sune; Hansen, Henning Sten; Aadahl, Mette

    2014-01-01

    or cycling to work or study each day and the distance to work or study. Data were obtained from the Danish National Health Survey collected in February to April 2010. Individual accessibility by public transportation was calculated using a multi-modal network in a GIS. Multilevel logistic regression was used...... individual public transportation accessibility and self-reported active commuting, and whether the associations varied with commute distance, age, and gender. METHODS: Twenty-eight thousand nine hundred twenty-eight commuters in The Capital Region of Denmark reported self-reported time spent either walking...... to analyze the association between accessibility, expressed as access area, and being an active commuter. RESULTS: Public transport accessibility area based on all stops within walking and cycling distance was positively associated with being an active commuter. Distance to work, age, and gender modified...

  5. The commutation error of the space averaged Navier-Stokes equations on a bounded domain

    Energy Technology Data Exchange (ETDEWEB)

    Dunca, A.; Layton, W.J. [Pittsburgh Univ., PA (United States). Dept. of Mathematics; John, V. [Magdeburg Univ. (Germany). Inst. fuer Analysis und Numerik

    2002-01-01

    In Large Eddy Simulation of turbulent flows, the Navier-Stokes equations are convolved with a filter and differentiation and convolution are interchanged, introducing an extra commutation error term, which is nearly universally dropped from the resulting equations. We show that the commutation error is asymptotically negligible in L{sup p}(R{sup d}) (i.e., it vanishes as the averaging radius {delta}{yields}0) if and only if the fluid and the boundary exert exactly zero force on each other. Next, we show that the commutation error tends to zero in H{sup -1}({omega}) as {delta}{yields}0. Convergence is proven also for a weak form of the commutation error. The order of convergence is studied in both cases. Last, we study the influence of the commutation error on the energy balance of the filtered equations. (orig.)

  6. Control Measures and Health Effects of Air Pollution: A Survey among Public Transportation Commuters in Malaysia

    Directory of Open Access Journals (Sweden)

    Li Ping Wong

    2017-09-01

    Full Text Available This research aimed to investigate the control measures used by public transport commuters and their health (physical and psychological effects due to exposure to air pollution during their daily commute and during haze days. From June to October 2016, 800 public transport commuters in urban cities in the heart of Selangor, Malaysia were interviewed. Of these, 25.4% reported sometimes/often wearing surgical masks during their daily commute, while 92.1% reported such use during haze days. The total control measure score against air pollutants during the daily commute was low; on a control measure scale of 0–18, the median rating during the daily commute was 8 (interquartile range (IQR 6–10. During haze days, control measures improved slightly (median 14, IQR 12–16. Evidence of adverse health effects was present. During the daily commute under normal conditions, the three highest adverse health experiences were fatigue and weakness (35.5%, coughing (23.6%, and dizziness (18.2%. During haze days, the three highest adverse health experiences were headache (85%, coughing (84.8%, and breathing difficulties (84.5%. On a possible total adverse health (physical and psychological experience scale of 0–22, the median rating during the daily commute was 1 (IQR 0–3. The median rating during haze days was intensified (median 11, IQR 9–13. Public transportation commuters should be encouraged to enhance various control measures against particulate air pollutants during their daily commute, particularly during haze days, to minimize the adverse health risks associated with air pollutants.

  7. The relationship between bicycle commuting and perceived stress: a cross-sectional study

    Science.gov (United States)

    Avila-Palencia, Ione; de Nazelle, Audrey; Cole-Hunter, Tom; Donaire-Gonzalez, David; Jerrett, Michael; Rodriguez, Daniel A; Nieuwenhuijsen, Mark J

    2017-01-01

    Introduction Active commuting — walking and bicycling for travel to and/or from work or educational addresses — may facilitate daily, routine physical activity. Several studies have investigated the relationship between active commuting and commuting stress; however, there are no studies examining the relationship between solely bicycle commuting and perceived stress, or studies that account for environmental determinants of bicycle commuting and stress. The current study evaluated the relationship between bicycle commuting, among working or studying adults in a dense urban setting, and perceived stress. Methods A cross-sectional study was performed with 788 adults who regularly travelled to work or study locations (excluding those who only commuted on foot) in Barcelona, Spain. Participants responded to a comprehensive telephone survey concerning their travel behaviour from June 2011 through to May 2012. Participants were categorised as either bicycle commuters or non-bicycle commuters, and (based on the Perceived Stress Scale, PSS-4) as either stressed or non-stressed. Multivariate Poisson regression with robust variance models of stress status based on exposures with bicycle commuting were estimated and adjusted for potential confounders. Results Bicycle commuters had significantly lower risk of being stressed than non-bicycle commuters (Relative Risk; RR (95% CI)=0.73 (0.60 to 0.89), p=0.001). Bicycle commuters who bicycled 4 days per week (RR (95% CI)=0.42 (0.24 to 0.73), p=0.002) and those who bicycled 5 or more days per week (RR (95% CI)=0.57 (0.42 to 0.77), pstressed than those who bicycled less than 4 days. This relationship remained statistically significant after adjusting for individual and environmental confounders and when using different cut-offs of perceived stress. Conclusions Stress reduction may be an important consequence of routine bicycle use and should be considered by decision makers as another potential benefit of its

  8. Built environment and active commuting: Rural-urban differences in the U.S

    Directory of Open Access Journals (Sweden)

    Jessie X. Fan

    2017-12-01

    Full Text Available The purpose of this research was to investigate rural-urban differences in participation rates in three modes of active commuting (AC and their built environmental correlates. The 2010 Census supplemented with other datasets were used to analyze AC rates in percent of workers age 16+ walking, biking, or taking public transportation to work in 70,172 Census tracts, including 12,844 rural and 57,328 urban. Random-intercept factional logit regressions were used to account for zero-inflated data and for clustering of tracts within counties. We found that the average AC rates were 3.44% rural and 2.77% urban (p<0.01 for walking to work, 0.40% rural and 0.58% urban (p<0.01 for biking to work, and 0.59% rural and 5.86% urban (p<0.01 for public transportation to work. Some environmental variables had similar relationships with AC in rural and urban tracts, such as a negative association between tract greenness and prevalence of walking to work. Others had opposite correlational directions for rural vs. urban, such as street connectivity for walking to work and population density for both walking to work and public transportation to work. We concluded that rurality is an important moderator in AC-environment relationships. In developing strategies to promote AC, attention needs to be paid to rural-urban differences to avoid unintended consequences.

  9. Built Environment and Active Commuting: Rural-Urban Differences in the U.S.

    Science.gov (United States)

    Fan, Jessie X; Wen, Ming; Wan, Neng

    2017-12-01

    The purpose of this research was to investigate rural-urban differences in participation rates in three modes of active commuting (AC) and their built environmental correlates. The 2010 Census supplemented with other datasets were used to analyze AC rates in percent of workers age 16+ walking, biking, or taking public transportation to work in 70,172 Census tracts, including 12,844 rural and 57,328 urban. Random-intercept factional logit regressions were used to account for zero-inflated data and for clustering of tracts within counties. We found that the average AC rates were 3.44% rural and 2.77% urban (pwalking to work, 0.40% rural and 0.58% urban (pwalking to work. Others had opposite correlational directions for rural vs. urban, such as street connectivity for walking to work and population density for both walking to work and public transportation to work. We concluded that rurality is an important moderator in AC-environment relationships. In developing strategies to promote AC, attention needs to be paid to rural-urban differences to avoid unintended consequences.

  10. Dirac oscillator in a Galilean covariant non-commutative space

    Energy Technology Data Exchange (ETDEWEB)

    Melo, G.R. de [Universidade Federal do Reconcavo da Bahia, BA (Brazil); Montigny, M. [University of Alberta (Canada); Pompeia, P.J. [Instituto de Fomento e Coordecacao Industrial, Sao Jose dos Campos, SP (Brazil); Santos, Esdras S. [Universidade Federal da Bahia, Salvador (Brazil)

    2013-07-01

    Full text: Even though Galilean kinematics is only an approximation of the relativistic kinematics, the structure of Galilean kinematics is more intricate than relativistic kinematics. For instance, the Galilean algebra admits a nontrivial central extension and projective representations, whereas the Poincare algebra does not. It is possible to construct representations of the Galilei algebra with three possible methods: (1) directly from the Galilei algebra, (2) from contractions of the Poincare algebra with the same space-time dimension, or (3) from the Poincare algebra in a space-time with one additional dimension. In this paper, we follow the third approach, which we refer to as 'Galilean covariance' because the equations are Lorentz covariant in the extended manifold. These equations become Galilean invariant after projection to the lower dimension. Our motivation is that this covariant approach provides one more unifying feature of field theory models. Indeed, particle physics (with Poincare kinematics) and condensed matter physics (with Galilean kinematics) share many tools of quantum field theory (e.g. gauge invariance, spontaneous symmetry breaking, Goldstone bosons), but the Galilean kinematics does not admit a metric structure. However, since the Galilean Lie algebra is a subalgebra of the Poincare Lie algebra if one more space-like dimension is added, we can achieve 'Galilean covariance' with a metric in an extended manifold; that makes non-relativistic models look similar to Lorentz-covariant relativistic models. In this context we study the Galilei covariant five-dimensional formulation applied to Galilean Dirac oscillator in a non-commutative situation, with space-space and momentum-momentum non-commutativity. The wave equation is obtained via a 'Galilean covariant' approach, which consists in projecting the covariant motion equations from a (4, l)-dimensional manifold with light-cone coordinates, to a (3, l

  11. ‘We are the future’: understanding adolescents’ intentions to commute by car or bicycle as adults

    DEFF Research Database (Denmark)

    Sigurdardottir, Sigrun Birna; Kaplan, Sigal; Møller, Mette

    This study focuses on the intentions of adolescents to commute by car or bicycle as adults, as key elements towards promoting societal transition towards sustainable modes. The behavioral model is based on the theory of planned behavior combined with positive current travel experience, willingness...... to accept car restrictions, transport-related future vision, environmental concern and social influence. Data are retrieved from a survey among 15-years old Danish adolescents, and are analyzed with structural equation models. Results show: (i) car use intentions are positively related to positive car...... passenger experience, general interest in cars, and car-ownership norms, and are negatively related to willingness to accept car restrictions and perceived lack of behavioral control; (ii) cycling intentions are positively related to positive cycling experience, willingness to accept car restrictions...

  12. Baryon number violation and novel canonical anti-commutation relations

    Science.gov (United States)

    Fujikawa, Kazuo; Tureanu, Anca

    2018-02-01

    The possible neutron-antineutron oscillation is described by an effective quadratic Lagrangian analogous to the BCS theory. It is shown that the conventional equal-time anti-commutation relations of the neutron variable n (t , x →) are modified by the baryon number violating terms. This is established by the Bjorken-Johnson-Low prescription and also by the canonical quantization combined with equations of motion. This novel canonical behavior can give rise to an important physical effect, which is illustrated by analyzing the Lagrangian that violates the baryon number but gives rise to the degenerate effective Majorana fermions and thus no neutron-antineutron oscillation. Technically, this model is neatly treated using a relativistic analogue of the Bogoliubov transformation.

  13. Commutative deformations of general relativity: nonlocality, causality, and dark matter

    Energy Technology Data Exchange (ETDEWEB)

    De Vegvar, P.G.N. [SWK Research, Bellingham, WA (United States)

    2017-01-15

    Hopf algebra methods are applied to study Drinfeld twists of (3+1)-diffeomorphisms and deformed general relativity on commutative manifolds. A classical nonlocality length scale is produced above which microcausality emerges. Matter fields are utilized to generate self-consistent Abelian Drinfeld twists in a background independent manner and their continuous and discrete symmetries are examined. There is negligible experimental effect on the standard model of particles. While baryonic twist producing matter would begin to behave acausally for rest masses above ∝1-10 TeV, other possibilities are viable dark matter candidates or a right-handed neutrino. First order deformed Maxwell equations are derived and yield immeasurably small cosmological dispersion and produce a propagation horizon only for photons at or above Planck energies. This model incorporates dark matter without any appeal to extra dimensions, supersymmetry, strings, grand unified theories, mirror worlds, or modifications of Newtonian dynamics. (orig.)

  14. The Higgs Mechanism in Non-commutative Gauge Theories

    Energy Technology Data Exchange (ETDEWEB)

    Petriello, Frank J

    2001-01-17

    This paper investigates the non-commutative version of the Abelian Higgs model at the one loop level. We find that the BRST invariance of the theory is maintained at this order in perturbation theory, rendering the theory one-loop renormalizable. Upon removing the gauge field from the theory we also obtain a consistent continuum renormalization of the broken O(2) linear sigma model, contradicting results found in the literature. The beta functions for the various couplings of the gauged U(1) theory are presented, as are the divergent contributions to every one particle irreducible (1PI) function. We find that all physical couplings and masses are gauge independent. A brief discussion concerning the symmetries P, C, and T in this theory is also given.

  15. The Return of Organisation Man: Commuter Narratives and Suburban Critique

    Directory of Open Access Journals (Sweden)

    Melissa Gregg

    2012-09-01

    Full Text Available This article considers the significance of suburban commuter imagery in a selection of screen visions of mid-century modernity. A number of examples, including Mad Men, and the screen adaptations of The Man in the Grey Flannel Suit (1956 and Revolutionary Road (2008, will be shown to echo key themes, symbols and scenes in their depictions of suburbia and the cultural impact of the corporation. Taken together, these narratives indicate the resilience of the “Organization Man” (Whyte 1956 as a figure marking the tension between individualism and conformity. It is this tension that the archetypal businessman’s uniform continues to symbolise in popular culture, even if, as this paper will argue, it is no longer the most fitting expression available.

  16. Geodesics in hypercomplex number systems. Application to commutative quaternions

    Energy Technology Data Exchange (ETDEWEB)

    Catoni, Francesco; Zampetti, Paolo [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Energia; Cannata, Roberto [ENEA, Centro Ricerche Casaccia, Rome (Italy). Funzione Centrale INFO; Bordoni, Luciana [ENEA, Centro Ricerche Casaccia, Rome (Italy). Funzione Centrale Studi

    1997-10-01

    The functions of hypercomplex variable can be related to the physical fields. Following the Einstein`s ideas, by which the Theory of General Relativity was developed, they want to verify if a generalisation is possible, in order to described the motion of a body in a gravitational field, by the geodesics in spaces ``deformed`` by functional transformations of hypercomplex variables. These number systems introduce new space symmetries. This paper is just a first step in the more extended study. As a first application they consider the ``commutative quaternions`` system that may be considered as a composition of complex and hyperbolic numbers. By using in this system the same functional transformations valid for the two dimensional case, elliptical geodesics are obtained, with the eccentricity related to the angle between the orbit plane and a reference plane. These geodesics do not describe the Kepler orbits, but they show a space anisotropy that might be related to planet orbits of the solar system.

  17. Is the environment near school associated with active commuting to school among preschoolers?

    Directory of Open Access Journals (Sweden)

    Jose Cazuza Farias Junior

    2013-05-01

    Full Text Available Available studies show that environmental factors may influence how parentes choose to commute their children from home to school. Thus, the aim of this study was to analyze the association between the characteristics of the physical and social environment near school and active commuting to school among preschool children. A school-based cross-sectional study with a sample of children aged 3to 5 years (n=914 was undertaken. Participants were selected by a single-stage cluster sampling process. To obtain data on commuting to school and demographicand socioeconomic variables, a previously validated questionnaire was used while an audit tool was used to assess the environment near school. Binarylogistic regression was used to analyze the association and results were presented as Odds Ratio values. Results showed that 28.3% (95%CI 25.5-31.3 ofthe children were active commuters from home to school. A positive association was found between public transportation (p=0.002 and social environment(p=0.004 domains and active commuting. However, this association was foundonly among children from families that did not have a car. The likelihood of achild being an active commuter was higher among those who are enrolled in schools with better environmental surroundings (OR=1.88; 95%CI 1.31-2.70. It was concluded that there was a positive association between some of the environmental factors near school and active commuting to school among children from families that did not have a car.

  18. Active commuting and perceptions of the route environment: a longitudinal analysis.

    Science.gov (United States)

    Panter, Jenna; Griffin, Simon; Ogilvie, David

    2014-10-01

    To assess associations between changes in perceptions of the environment en route to work and changes in active commuting. 655 commuters in Cambridge, UK reported perceptions of their commuting route and past-week commuting trips in postal questionnaires in 2009 and 2010. Associations between changes in route perceptions and changes in time spent walking and cycling, proportion of car trips, and switching to or from the car on the commute were modelled using multivariable regression. Changes in only a few perceptions were associated with changes in travel behaviour. Commuters who reported that it became less pleasant to walk recorded a 6% (95% CI: 1, 11) net increase in car trips and a 12 min/week (95% CI: -1, -24) net decrease in walking. Increases in the perceived danger of cycling or of crossing the road were also associated with increases in car trips. Increases in the perceived convenience of public transport (OR: 3.31, 95% CI: 1.27, 8.63) or safety of cycling (OR: 3.70, 95% CI: 1.44, 9.50) were associated with taking up alternatives to the car. Interventions to improve the safety of routes and convenience of public transport may help promote active commuting and should be evaluated. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Reducing drag of a commuter train, using engine exhaust momentum

    Science.gov (United States)

    Ha, Dong Keun

    The objective of this thesis was to perform numerical investigations of two different methods of injecting fluid momentum into the air flow above a commuter train to reduce its drag. Based on previous aerodynamic modifications of heavy duty trucks in improving fuel efficiency, two structural modifications were designed and applied to a Metrolink Services commuter train in the Los Angeles (LA) County area to reduce its drag and subsequently improve fuel efficiency. The first modification was an L-shaped channel, added to the exhaust cooling fan above the locomotive roof to divert and align the exhaust gases in the axial direction. The second modification was adding an airfoil shaped lid over the L-shape channel, to minimize the drag of the perturbed structure, and thus reduce the overall drag. The computational fluid dynamic (CFD) software CCM+ from CD-Adapco with the ?-? turbulence model was used for the simulations. A single train set which consists of three vehicles: one locomotive, one trailer car and one cab car were used. All the vehicles were modeled based on the standard Metrolink fleet train size. The wind speed was at 90 miles per hour (mph), which is the maximum speed for the Orange County Metrolink line. Air was used as the exhaust gas in the simulation. The temperature of the exhausting air emitting out of the cooling fan on the roof was 150 F and the average fan speed was 120 mph. Results showed that with the addition of the lid, momentum injection results in reduced flow separation and pressure recovery behind the locomotive, which reduces the overall drag by at least 30%.

  20. Spontaneous usage of different shortcuts based on the commutativity principle.

    Directory of Open Access Journals (Sweden)

    Robert Gaschler

    Full Text Available Based on research on expertise a person can be said to possess integrated conceptual knowledge when she/he is able to spontaneously identify task relevant information in order to solve a problem efficiently. Despite the lack of instruction or explicit cueing, the person should be able to recognize which shortcut strategy can be applied--even when the task context differs from the one in which procedural knowledge about the shortcut was originally acquired. For mental arithmetic, first signs of such adaptive flexibility should develop already in primary school. The current study introduces a paper-and-pencil-based as well as an eyetracking-based approach to unobtrusively measure how students spot and apply (known shortcut options in mental arithmetic. We investigated the development and the relation of the spontaneous use of two strategies derived from the mathematical concept of commutativity. Children from grade 2 to grade 7 and university students solved three-addends addition problems, which are rarely used in class. Some problems allowed the use of either of two commutativity-based shortcut strategies. Results suggest that from grade three onwards both of the shortcuts were used spontaneously and application of one shortcut correlated positively with application of the other. Rate of spontaneous usage was substantial but smaller than in an instructed variant. Eyetracking data suggested similar fixation patterns for spontaneous an instructed shortcut application. The data are consistent with the development of an integrated concept of the mathematical principle so that it can be spontaneously applied in different contexts and strategies.

  1. Spontaneous usage of different shortcuts based on the commutativity principle.

    Science.gov (United States)

    Gaschler, Robert; Vaterrodt, Bianca; Frensch, Peter A; Eichler, Alexandra; Haider, Hilde

    2013-01-01

    Based on research on expertise a person can be said to possess integrated conceptual knowledge when she/he is able to spontaneously identify task relevant information in order to solve a problem efficiently. Despite the lack of instruction or explicit cueing, the person should be able to recognize which shortcut strategy can be applied--even when the task context differs from the one in which procedural knowledge about the shortcut was originally acquired. For mental arithmetic, first signs of such adaptive flexibility should develop already in primary school. The current study introduces a paper-and-pencil-based as well as an eyetracking-based approach to unobtrusively measure how students spot and apply (known) shortcut options in mental arithmetic. We investigated the development and the relation of the spontaneous use of two strategies derived from the mathematical concept of commutativity. Children from grade 2 to grade 7 and university students solved three-addends addition problems, which are rarely used in class. Some problems allowed the use of either of two commutativity-based shortcut strategies. Results suggest that from grade three onwards both of the shortcuts were used spontaneously and application of one shortcut correlated positively with application of the other. Rate of spontaneous usage was substantial but smaller than in an instructed variant. Eyetracking data suggested similar fixation patterns for spontaneous an instructed shortcut application. The data are consistent with the development of an integrated concept of the mathematical principle so that it can be spontaneously applied in different contexts and strategies.

  2. Levels of ambient air pollution according to mode of transport: a systematic review.

    Science.gov (United States)

    Cepeda, Magda; Schoufour, Josje; Freak-Poli, Rosanne; Koolhaas, Chantal M; Dhana, Klodian; Bramer, Wichor M; Franco, Oscar H

    2017-01-01

    Controversy exists about the differences in air pollution exposure and inhalation dose between mode of transport. We aimed to review air pollution exposure and inhaled dose according to mode of transport and pollutant and their effect in terms of years of life expectancy (YLE). In this systematic review, we searched ten online databases from inception to April 13, 2016, without language or temporal restrictions, for cohort, cross-sectional, and experimental studies that compared exposure to carbon monoxide, black carbon, nitrogen dioxide, and fine and coarse particles in active commuters (pedestrian or cyclist) and commuters using motorised transport (car, motorcycle, bus, or massive motorised transport [MMT-ie, train, subway, or metro]). We excluded studies that measured air pollution exposure exclusively with biomarkers or on the basis of simulated data, reviews, comments, consensuses, editorials, guidelines, in-vitro studies, meta-analyses, ecological studies, and protocols. We extracted average exposure and commuting time per mode of transport and pollutant to calculate inhaled doses. We calculated exposure and inhaled dose ratios using active commuters as the reference and summarised them with medians and IQRs. We also calculated differences in YLE due to fine particle inhaled dose and physical activity. We identified 4037 studies, of which 39 were included in the systematic review. Overall, car commuters had higher exposure to all pollutants than did active commuters in 30 (71%) of 42 comparisons (median ratio 1·22 [IQR 0·90-1·76]), followed by those who commuted by bus in 57 (52%) of 109 (1·0 [0·79-1·41]), by motorcycle in 16 (50%) of 32 (0·99 [0·86-1·38]), by a car with controlled ventilation settings in 39 (45%) of 86 (0·95 [0·66-1·54]), and by MMT in 21 (38%) of 55 (0·67 [0·49-1·13]). Overall, active commuters had higher inhalation doses than did commuters using motorised transport (median ratio car with controlled ventilation settings 0

  3. Road traffic injuries to children during the school commute in Hyderabad, India: cross-sectional survey.

    Science.gov (United States)

    Tetali, Shailaja; Edwards, P; Murthy, G V S; Roberts, I

    2016-06-01

    India is motorising rapidly. With increasing motorisation, road traffic injuries are predicted to increase. A third of a billion children travel to school every day in India, but little is known about children's safety during the school commute. We investigated road traffic injury to children during school journeys. We conducted a cross-sectional survey in Hyderabad using a two-stage stratified cluster sampling design. We used school travel questionnaires to record any road injury in the past 12 months that resulted in at least 1 day of school missed or required treatment by a doctor or nurse. We estimated the prevalence of road injury by usual mode of travel and distance to school. The total sample was 5842 children, of whom 5789 (99.1%) children answered the question on road injury. The overall prevalence of self-reported road injury in the last 12 months during school journeys was 17% (95% CI 12.9% to 21.7%). A higher proportion of boys (25%) reported a road injury than girls (11%). There was a strong association between road injury, travel mode and distance to school. Children who cycled to school were more likely to be injured compared with children who walked (OR 1.5; 95% CI 1.2 to 2.0). Travel by school bus was safer than walking (OR 0.5; 95% CI 0.3 to 0.9). A sixth of the children reported a road traffic injury in the past 12 months during school journeys in Hyderabad. Injury prevention interventions should focus on making walking and cycling safer for children. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  4. The photon-neutrino interaction in non-commutative gauge field theory and astrophysical bounds

    OpenAIRE

    Schupp, Peter; Trampetic, Josip; Wess, Julius; Raffelt, Georg

    2004-01-01

    In this letter we propose a possible mechanism of left- and right-handed neutrino couplings to photons, which arises quite naturally in non-commutative gauge field theory. We estimate the predicted additional energy-loss in stars induced by space-time non-commutativity. The usual requirement that any new energy-loss mechanism in globular stellar clusters should not excessively exceed the standard neutrino losses implies a scale of non-commutative gauge theory above the scale of weak interacti...

  5. modes of current conduction in 2-pulse pwm ac/dc converter

    African Journals Online (AJOL)

    Dr Obe

    gate insulated transistors (IGBTs) are used as the converter semiconductor switches while the switches in Fig. 2b are a combination of line commutated high speed ... types or modes of continuous and discontinuous load current operation are mainly determined, for a given ac input supply voltage, by the load parameters ...

  6. Socio-demographic, personal, environmental and behavioral correlates of different modes of transportation to work among Norwegian parents

    Directory of Open Access Journals (Sweden)

    Oline Anita Bjørkelund

    2016-10-01

    Full Text Available Abstract Background Cycling and brisk-walking to work represents an opportunity to incorporate sustainable transport related moderate- to- vigorous physical activity (MVPA into daily routine among adults, and thus, may make an important contributing to health. Despite the fact that walking and cycling is an option for many commuters and also brings a number of benefits, a considerable proportion of commuters choose to use other means of transport when cycling and walking would be a highly appropriate transport mode. The object of this study was to assess the associations between modes of commuting to the workplace among parental adults; taking socio-demographic, personal, environmental and behavioral factors into account. Methods Data from a cross- sectional questionnaire were collected from a sample of 709 parents (23 % men and 77 % women of children aged 10–12 years-old in two Norwegian counties, Hedmark and Telemark. Commuting behavior, socio- demographic determinants, personal and environmental factors were ascertained using questionnaire data from the Fruit and Vegetables Makes the Marks project (FVMM. Multivariate logistic regressions were applied. Results In total, 70 % of adults were categorized as car commuters to and from work, 12 % was categorized as a cyclist and 7 % as a walker. The multivariate analyses showed that active commuters were more likely to have a shorter distance to work and perceived the traffic as more safe. Moreover, those who actively commute to the workplace considered commuting as a way to obtain health benefits and a way to reduce CO2 emissions. Active commuters also considered weather to be an obstacle to active commuting. Conclusion In this cross-sectional study of parents living in sub-urban Norway, we found that active commuting to and from the workplace were associated with a shorter distance to work, traffic safety, environmental concern, health benefits and weather condition. In light of these

  7. Evaluation of bipartite entanglement between two optical multi-mode systems using mode translation symmetry

    Science.gov (United States)

    Wu, Jun-Yi; Hofmann, Holger F.

    2017-10-01

    Optical multi-mode systems provide large scale Hilbert spaces that can be accessed and controlled using single photon sources, linear optics and photon detection. Here, we consider the bipartite entanglement generated by coherently distributing M photons in M modes to two separate locations, where linear optics and photon detection is used to verify the non-classical correlations between the two M-mode systems. We show that the entangled state is symmetric under mode shift operations performed in the two systems and use this symmetry to derive correlations between photon number distributions detected after a discrete Fourier transform (DFT) of the modes. The experimentally observable correlations can be explained by a simple and intuitive rule that relates the sum of the output mode indices to the eigenvalue of the input state under the mode shift operation. Since the photon number operators after the DFT do not commute with the initial photon number operators, entanglement is necessary to achieve strong correlations in both the initial mode photon numbers and the photon numbers observed after the DFT. We can therefore derive entanglement witnesses based on the experimentally observable correlations in both photon number distributions, providing a practical criterion for the evaluation of large scale entanglement in optical multi-mode systems. Our method thus demonstrates how non-classical signatures in large scale optical quantum circuits can be accessed experimentally by choosing an appropriate combination of modes in which to detect the photon number distributions that characterize the quantum coherences of the state.

  8. Choice certainty in Discrete Choice Experiments

    DEFF Research Database (Denmark)

    Uggeldahl, Kennet Christian; Jacobsen, Catrine; Lundhede, Thomas

    2016-01-01

    In this study, we conduct a Discrete Choice Experiment (DCE) using eye tracking technology to investigate if eye movements during the completion of choice sets reveal information about respondents’ choice certainty. We hypothesise that the number of times that respondents shift their visual...... attention between the alternatives in a choice set reflects their stated choice certainty. Based on one of the largest samples of eye tracking data in a DCE to date, we find evidence in favor of our hypothesis. We also link eye tracking observations to model-based choice certainty through parameterization...... of the scale function in a random parameters logit model. We find that choices characterized by more frequent gaze shifting do indeed exhibit a higher degree of error variance, however, this effects is insignificant once response time is controlled for. Overall, findings suggest that eye tracking can provide...

  9. EnviroAtlas - Commute Time to Work by Census Block Group for the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset portrays the commute time of workers to their workplace for each Census Block Group (CBG) during 2008-2012. Data were compiled from the...

  10. INdAM Meeting on Homological and Computational Methods in Commutative Algebra

    CERN Document Server

    Gubeladze, Joseph; Römer, Tim

    2017-01-01

    This volume collects contributions by leading experts in the area of commutative algebra related to the  INdAM meeting “Homological and Computational Methods in Commutative Algebra” held in Cortona (Italy) from May 30 to  June 3, 2016 . The conference and this volume are dedicated to Winfried Bruns on the occasion of his 70th birthday. In particular, the topics of this book strongly reflect the variety of Winfried Bruns’ research interests and his great impact on commutative algebra as well as its applications to related fields. The authors discuss recent and relevant developments in algebraic geometry, commutative algebra, computational algebra, discrete geometry and homological algebra. The book offers a unique resource, both for young and more experienced researchers seeking comprehensive overviews and extensive bibliographic references.

  11. Daily time budgets of long-distance commuting workers in Tokyo megalopolis.

    Science.gov (United States)

    Umezaki, M; Ishimaru, H; Ohtsuka, R

    1999-01-01

    In Tokyo Megalopolis, long-distance commuting between residences in the suburbs and work places in the centre of the city was examined. Using a questionnaire, heads of household in two suburbs were asked about the influences of long commuting hours on their daily time budgets. The results showed that on workdays, the workers who spent longer commuting rose and left home for work earlier, and came back home and retired later; accordingly, both time spent on in-home activities on workdays and hours slept on the day before a workday were shorter. Comparison of time budgets between the subjects who work 5 and 6 days per week revealed more vulnerable influences of long commuting hours in the former than the latter. The expected health consequences of these findings are discussed from a biosocial/human ecological viewpoint.

  12. Vibration and Acoustic Noise Characteristic on SRM with compensating winding by two stage commutation

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Seok Gyu; Choi, Tae Wan [Chinju National University (Korea); Lee, Jong Gun [Kumho Electronics Co., Ltd. (Korea)

    2001-06-01

    SRM drives generate large vibration and acoustic noise because it is rotated by step pulse mmf and switching commutation mechanism. The main vibration source of SRM drive is generated by rapidly variation of radial force when phase winding current is extinguished for commutation action. So the rapidly variation of radial force is repressed firstly to reduce vibrating force of SRM drive. This paper suggests an SRM excitation scheme using unidirect-short compensation winding to reduce vibration of the motor. The motor is excited by a two stage commutation method during commutation period. This reduction effect of vibration is verified with the result obtained in the test of prototype machine. (author). 7 refs., 11 figs.

  13. On noncommutative deformations, cohomology of color-commutative algebras and formal smoothness

    OpenAIRE

    Gohr, Aron Samuel

    2009-01-01

    The main topic under study in the present work is the deformation theory of color algebras. Color algebras are generalized analogues of associative superalgebras, where the underlying grading can be over an arbitrary abelian group and the Koszul sign is replaced by a bicharacter from the group into the base ring. A special case of particular interest are color-commutative algebras, which satisfy a commutation identity similar to (but much more general than) supercommutative algebras. Examples...

  14. Group-specific analysis of commuting in the most disadvantaged areas of Hungary

    OpenAIRE

    Alpek B., Levente; Tésits, Róbert; Bokor, László

    2016-01-01

    The study aims to examine the commuting opportunities of the most disadvantaged job seeker groups living in Hungary's most disadvantaged regions, as well as Hungary’s spatial and group-specific boundary conditions. The study also aims to develop and present an indexation process (fMFÁ model), allowing the measurement of the mobility degree of different territorial units (in this case, the municipalities) and effects of certain factors determining commuting (transport subsidies, individual cho...

  15. The effects of sprawl on private-vehicle commuting distances and times

    OpenAIRE

    Edmund J Zolnik

    2011-01-01

    Sprawl is a well-known consequence of the suburbanization of the United States population. However, only recently have scholars shown interest in the effects of sprawl on transportation outcomes. For example, little research on how sprawl affects private-vehicle commuting distances and times is evident in the literature. To explore further the relationship between sprawl and private-vehicle commuting distances and times, a multilevel approach is adopted. Using microdata for households and mac...

  16. Changing population structure and commuting situation in Tokyo Megalopolis: a municipality-based analysis.

    Science.gov (United States)

    Ohtsuka, R; Umezaki, M

    1993-06-01

    Census data was analyzed for 20 municipalities along the Tohoku Line in Tokyo Megalopolis to elucidate the changes in the population structure and the commuting situation in the last two decades. The major findings were: (1) the changing pattern of population structure markedly varied among the municipalities, and (2) the long-distance commuting workers have increased particularly among those 50 km or more from central Tokyo.

  17. Effects of Light and Commuter Rail Transit on Land Prices: Experiences in San Diego County

    OpenAIRE

    Cervero, Robert

    2006-01-01

    Using hedonic price models, appreciable land-value premiums were found for multiple land uses in different rail corridors of San Diego County. The most appreciable benefits were for condominiums and single-family housing near commuter-rail stations in the north county, multi-family housing near light-rail stations, and commercial properties near downtown commuter-rail stations and light-rail stops in the Mission Valley. Elsewhere, commercial properties accrued small or even negative capitaliz...

  18. Exotic Galilean symmetry in the non-commutative plane and the Hall effect

    Energy Technology Data Exchange (ETDEWEB)

    Duval, C. [Centre de Physique Theorique, CNRS, Luminy, Marseille (France); Horvathy, P.A. [Laboratoire de Mathematiques et de Physique Theorique, Universite de Tours, Tours (France)

    2001-11-30

    Quantum mechanics in the non-commutative plane is shown to admit the 'exotic' symmetry of the doubly centrally extended Galilei group. When coupled to a planar magnetic field whose strength is the inverse of the non-commutative parameter, the system becomes singular, and 'Faddeev-Jackiw' reduction yields the 'Chern-Simons' mechanics of Dunne et al. The reduced system moves according to the Hall law. (author)

  19. Exploring Bikeability in a Suburban Metropolitan Area Using the Active Commuting Route Environment Scale (ACRES

    Directory of Open Access Journals (Sweden)

    Lina Wahlgren

    2014-08-01

    Full Text Available Background and Aim: Commuting by bicycle could contribute to public health, and route environments may influence this behaviour. Therefore, the aim of this study is to assess the potential associations between appraisals of the overall route environment as hindering or stimulating for bicycle commuting, with both perceptions of commuting route environmental factors in a suburban area and background factors. Methods: The Active Commuting Route Environment Scale (ACRES was used for the assessment of bicycle commuters’ perceptions and appraisals of their route environments in the suburban parts of Greater Stockholm, Sweden. A simultaneous multiple regression analysis was used to assess the relationship between the outcome variable whether the overall route environment hinders or stimulates bicycle commuting and environmental factors (e.g., exhaust fumes, speeds of motor vehicles, greenery, as well as background factors (sex, age, education, income as predictor variables. Results and Conclusions: The results indicate that in suburban areas, the factors aesthetics, greenery and bicycle paths seem to be, independently of each other, stimulating factors for bicycle commuting. On the other hand, flows of motor vehicles, noise, and low “directness” of the route seem to be hindering factors. A comparison of these results with those obtained from an inner urban area points to the importance of studying different types of built-up areas separately.

  20. Mitigation of commutation failures in LCC-HVDC systems based on superconducting fault current limiters

    Science.gov (United States)

    Lee, Jong-Geon; Khan, Umer Amir; Lee, Ho-Yun; Lim, Sung-Woo; Lee, Bang-Wook

    2016-11-01

    Commutation failure in line commutated converter based HVDC systems cause severe damages on the entire power grid system. For LCC-HVDC, thyristor valves are turned on by a firing signal but turn off control is governed by the external applied AC voltage from surrounding network. When the fault occurs in AC system, turn-off control of thyristor valves is unavailable due to the voltage collapse of point of common coupling (PCC), which causes the commutation failure in LCC-HVDC link. Due to the commutation failure, the power transfer interruption, dc voltage drop and severe voltage fluctuation in the AC system could be occurred. In a severe situation, it might cause the protection system to block the valves. In this paper, as a solution to prevent the voltage collapse on PCC and to limit the fault current, the application study of resistive superconducting fault current limiter (SFCL) on LCC-HVDC grid system was performed with mathematical and simulation analyses. The simulation model was designed by Matlab/Simulink considering Haenam-Jeju HVDC power grid in Korea which includes conventional AC system and onshore wind farm and resistive SFCL model. From the result, it was observed that the application of SFCL on LCC-HVDC system is an effective solution to mitigate the commutation failure. And then the process to determine optimum quench resistance of SFCL which enables the recovery of commutation failure was deeply investigated.

  1. Research of the Power Plant Operational Modes

    Directory of Open Access Journals (Sweden)

    Koismynina Nina M.

    2017-01-01

    Full Text Available In this article the algorithm of the power plant operational modes research is offered. According to this algorithm the program for the modes analysis and connection power transformers choice is developed. The program can be used as educational means for studying of the power plant electric part, at the same time basic data are provided. Also the program can be used for the analysis of the working power plants modes. Checks of the entered data completeness and a choice correctness of the operational modes are provided in the program; in all cases of a deviation from the correct decisions to the user the relevant information is given.

  2. Migration Dilemmas of Islanders: Commuting Leading to Migration or Remaining at Home

    Directory of Open Access Journals (Sweden)

    Ivan Lajić

    2001-09-01

    Full Text Available The paper presents and discusses the results of an empirical survey carried out in April 2000 on the islands Prvić, Zlarin and Krapanj in the Šibenik coastal area. These islands are part of a group of islands marked by the highest rates of depopulation, in which even recently daily commuting was one of the most expressed forms of mechanical population development. Daily commuting is seen as an initial state leading to permanent migration, i.e. to out-migration. Potential migrants become familiar with the social, economic, cultural and other traits of their future destination area, which makes it easier for them to leave their places of origin. Thus, for the purposes of the research, the survey selected a population of daily commuters, mainly young people of working age who usually constitute the segment of the population most Iikely to migrate. The survey used both a questionnaire and interviews. Respondents belonged to two relevant groups of the island population: employees commuting each day to work and pupils commuting daily to school. Even though the sample included practically the entire island population with the given migrational and socio-demographic characteristics, the total number of respondents was still too small for the application of standard methods of statistical analysis. In order to gain better insight into the pre-migrational situation on the islands, a few adult islander commuters were added to the group of commuting employees. The goal of the research was to gain an understanding of commuting phenomena in the island micro-society, especially of the migration dilemmas of young islanders. The most frequent variables in the survey were: island/settlement, gender and school. Commuting between the island and mainland is the dominant form of spatial mobility among islanders and constitutes an essential part of their daily life. The most frequent reasons for commuting among islanders are school attendance, going to work, going

  3. Fast Katz and commuters : efficient estimation of social relatedness.

    Energy Technology Data Exchange (ETDEWEB)

    On, Byung-Won; Lakshmanan, Laks V. S.; Esfandiar, Pooya; Bonchi, Francesco; Grief, Chen; Gleich, David F.

    2010-12-01

    Motivated by social network data mining problems such as link prediction and collaborative filtering, significant research effort has been devoted to computing topological measures including the Katz score and the commute time. Existing approaches typically approximate all pairwise relationships simultaneously. In this paper, we are interested in computing: the score for a single pair of nodes, and the top-k nodes with the best scores from a given source node. For the pairwise problem, we apply an iterative algorithm that computes upper and lower bounds for the measures we seek. This algorithm exploits a relationship between the Lanczos process and a quadrature rule. For the top-k problem, we propose an algorithm that only accesses a small portion of the graph and is related to techniques used in personalized PageRank computing. To test the scalability and accuracy of our algorithms we experiment with three real-world networks and find that these algorithms run in milliseconds to seconds without any preprocessing.

  4. Fully controlled 5-phase, 10-pulse, line commutated rectifier

    Directory of Open Access Journals (Sweden)

    Mahmoud I. Masoud

    2015-12-01

    Full Text Available The development and production of multiphase machines either generators or motors, specially five-phase, offers improved performance compared to three-phase counterpart. Five phase generators could generate power in applications such as, but not limited to, wind power generation, electric vehicles, aerospace, and oil and gas. The five-phase generator output requires converter system such as ac–dc converters. In this paper, a fully controlled 10-pulse line commutated rectifier, suitable to be engaged with wind energy applications, fed from five-phase source is introduced. A shunt active power filter (APF is used to improve power factor and supply current total harmonic distortion (THD. Compared to three-phase converters, 6-pulse or 12-pulse rectifiers, the 10-pulse rectifier engaged with 5-phase source alleviate their drawbacks such as high dc ripples and no need for electric gear or phase shifting transformer. MATLAB/SIMULINK platform is used as a simulation tool to investigate the performance of the proposed rectifier.

  5. Computational quantum-classical boundary of noisy commuting quantum circuits.

    Science.gov (United States)

    Fujii, Keisuke; Tamate, Shuhei

    2016-05-18

    It is often said that the transition from quantum to classical worlds is caused by decoherence originated from an interaction between a system of interest and its surrounding environment. Here we establish a computational quantum-classical boundary from the viewpoint of classical simulatability of a quantum system under decoherence. Specifically, we consider commuting quantum circuits being subject to decoherence. Or equivalently, we can regard them as measurement-based quantum computation on decohered weighted graph states. To show intractability of classical simulation in the quantum side, we utilize the postselection argument and crucially strengthen it by taking noise effect into account. Classical simulatability in the classical side is also shown constructively by using both separable criteria in a projected-entangled-pair-state picture and the Gottesman-Knill theorem for mixed state Clifford circuits. We found that when each qubit is subject to a single-qubit complete-positive-trace-preserving noise, the computational quantum-classical boundary is sharply given by the noise rate required for the distillability of a magic state. The obtained quantum-classical boundary of noisy quantum dynamics reveals a complexity landscape of controlled quantum systems. This paves a way to an experimentally feasible verification of quantum mechanics in a high complexity limit beyond classically simulatable region.

  6. High Power, Repetitive, Stacked Blumlein Pulse Generators Commuted by a Single Switching Element

    Science.gov (United States)

    Bhawalkar, Jayant Dilip

    In this work, the stacked Blumlein pulsers developed at the University of Texas at Dallas were characterized and shown to be versatile sources of pulse power for a variety of applications. These devices consisted of several triaxial Blumleins stacked in series at one end. The lines were charged in parallel and synchronously commuted repetitively with a single switching element at the other end. In this way, relatively low charging voltages were multiplied to give a high discharge voltage across an arbitrary load without the need for complex Marx bank circuitry. Several pulser parameters such as the number of stacked Blumlein lines, line configuration, type of switching element, and the length of the lines, were varied and the waveform characteristics were observed and analyzed. It was shown that these devices are capable of generating fast rising waveforms with a wide range of peak voltage and current values. The generation of high power waveforms with pulse durations in the range of 80-600 ns was demonstrated without degradation of the voltage gains. The results of this work indicated that unlike generators based on stacked transmission lines, the effects of parasitic modes were not appreciable for the stacked Blumlein pulsers. Opportunities for tactically packaging these pulsers were also investigated and a significant reduction in their size and weight was demonstrated. For this, dielectric lifetime and Blumlein spacing studies were performed on small scale prototypes. In addition to production of intense X-ray pulses, the possible applications for these novel pulsers include driving magnetrons for high power microwave generation, pumping laser media, or powering e-beam diodes. They could also serve as compact, tabletop sources of high power pulses for various research experiments.

  7. The socio-economic and environmental impact of school commuting : a case study of the Johannesburg Inner City

    OpenAIRE

    2014-01-01

    M.Sc. (Environmental Management) This study explores the school-commuting phenomenon that occurs across the city of Johannesburg, with specific reference to inner city private schools. It was hypothesized that the school commute, much of which has its origins in spatial apartheid, is financially and socially unsustainable. As spatial apartheid continues to dominate the urban landscape in Johannesburg, it is posited that overall, the school commute hinders the City of Johannesburg’s progres...

  8. Mode Combinations and International Operations

    DEFF Research Database (Denmark)

    Benito, Gabriel R. G.; Petersen, Bent; Welch, Lawrence S.

    2011-01-01

    An enduring characteristic of extant literature on foreign operation modes is its discrete choice approach, where companies are assumed to choose one among a small number of distinctive alternatives. In this paper we use detailed information about the operations of six Norwegian companies in three...... key markets (China, UK and USA) as the basis for an exploration of the extent to which, and how and why, companies combine clearly different foreign operation modes. We examine their use of foreign operation mode combinations within given value activities as well as within given countries. The study...... reveals that companies tend to combine modes of operation; thereby producing unique foreign operation mode “packages” for given activities and/or countries, and that the packages are liable to be modified over time – providing a potentially important optional path for international expansion. Our data...

  9. Mode Combinations and International Operations

    DEFF Research Database (Denmark)

    Benito, Gabriel R. G.; Petersen, Bent; Welch, Lawrence S.

    2011-01-01

    An enduring characteristic of extant literature on foreign operation modes is its discrete choice approach, where companies are assumed to choose one among a small number of distinctive alternatives. In this paper, detailed information about the operations of six Norwegian companies in three key...... markets (China, UK and USA) is used as the basis for an exploration of the extent to which, and how and why, companies combine clearly different foreign operation modes. We examine their use of foreign operation mode combinations within given value activities as well as within given countries. The study...... reveals that companies tend to combine modes of operation; thereby producing unique foreign operation mode “packages” for given activities and/or countries, and that the packages are liable to be modified over time—providing a potentially important optional path for international expansion. The data show...

  10. Toeplitz Quantization for Non-commutating Symbol Spaces such as SUq(2

    Directory of Open Access Journals (Sweden)

    Sontz Stephen Bruce

    2016-08-01

    Full Text Available Toeplitz quantization is defined in a general setting in which the symbols are the elements of a possibly non-commutative algebra with a conjugation and a possibly degenerate inner product. We show that the quantum group SUq(2 is such an algebra. Unlike many quantization schemes, this Toeplitz quantization does not require a measure. The theory is based on the mathematical structures defined and studied in several recent papers of the author; those papers dealt with some specific examples of this new Toeplitz quantization. Annihilation and creation operators are defined as densely defined Toeplitz operators acting in a quantum Hilbert space, and their commutation relations are discussed. At this point Planck’s constant is introduced into the theory. Due to the possibility of non-commuting symbols, there are now two definitions for anti-Wick quantization; these two definitions are equivalent in the commutative case. The Toeplitz quantization introduced here satisfies one of these definitions, but not necessarily the other. This theory should be considered as a second quantization, since it quantizes non-commutative (that is, already quantum objects. The quantization theory presented here has two essential features of a physically useful quantization: Planck’s constant and a Hilbert space where natural, densely defined operators act.

  11. Pilot age and geographic region of commuter and air taxi crashes: a case-control study.

    Science.gov (United States)

    Rebok, George W; Qiang, Yandong; Baker, Susan P; Li, Guohua

    2011-02-01

    Previous studies of major airline and general aviation crashes have identified a host of risk factors. We examined risk factors related to crashes involving commuter air carrier and air taxi flights. A matched case-control design was applied to assess the association of pilot age, total flight time, and geographic region with commuter air carrier and air taxi crashes (14 CFR Part 135) from 1983-2002 in the United States. A total of 2033 commuter air carrier or air taxi crashes from the National Transportation Safety Board aviation crash database were identified as eligible cases. Controls were randomly selected incidents from the Federal Aviation Administration's (FAA) aviation incident database coded under Part 135 operation. Relative to controls, commuter air carrier and air taxi crashes were less likely to occur in pilots under 30 yr of age (adjusted odds ratio 0.68, 95% confidence interval 0.54-0.88) after adjusting for geographic region and total flight time. With adjustment for pilot age and total flight time, the commuter air carrier and air taxi crashes with pilot error were nearly 13 times as likely to be in Alaska as their matched controls (adjusted odds ratio 12.84, 95% confidence interval 5.24-31.45). These results suggest that pilot age may be associated with risk of crash involvement in Part 135 operations. The excess crash risk in Alaska with or without pilot error underscores the importance of environmental hazards in flight safety.

  12. Choice Probability Generating Functions

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; McFadden, Daniel L; Bierlaire, Michel

    This paper considers discrete choice, with choice probabilities coming from maximization of preferences from a random utility field perturbed by additive location shifters (ARUM). Any ARUM can be characterized by a choice-probability generating function (CPGF) whose gradient gives the choice...... probabilities, and every CPGF is consistent with an ARUM. We relate CPGF to multivariate extreme value distributions, and review and extend methods for constructing CPGF for applications....

  13. Dynamics of Foreign Operations Modes and Their Combinations

    DEFF Research Database (Denmark)

    Benito, Gabriel R. G.; Petersen, Bent; Welch, Lawrence S.

    Companies’ choice of foreign operation modes (FOM) has been a core subject of international business studies basically from its beginning (Hymer, 1960 [1976]; Root, 1964). A halfcentury of research has brought us a set of established perspectives on companies’ foreign operation mode choices...

  14. Effectiveness and implementation of interventions to increase commuter cycling to school

    DEFF Research Database (Denmark)

    Østergaard, Lars; Støckel, Jan Toftegaard; Andersen, Lars Bo

    2015-01-01

    BACKGROUND: Active transportation to school has been positively associated with various health parameters whereas only sparse evidence exists on risk of injury while commuting to school. This study investigated the overall effectiveness of cycling promotion combined with structural changes...... = 12) or intervention schools (n = 13). All children (n = 2415) from the 4(th) and 5(th) grade were measured at baseline during spring 2010 and at follow-up one year later. RESULTS: No significant differences in commuter cycling were detected in the adjusted analyses comparing the intervention...... on cycling to school. METHODS: Interventions at public schools in three different regions in Denmark were based on planned infrastructural changes near schools (e.g. road surface and traffic regulation) and school-motivation for promoting commuter cycling. Participants were pupils from control schools (n...

  15. Complete commutative subalgebras in polynomial poisson algebras: A proof of the Mischenko-Fomenko conjecture

    Directory of Open Access Journals (Sweden)

    Bolsinov Alexey V.

    2016-01-01

    Full Text Available The Mishchenko-Fomenko conjecture says that for each real or complex finite-dimensional Lie algebra g there exists a complete set of commuting polynomials on its dual space g*. In terms of the theory of integrable Hamiltonian systems this means that the dual space g* endowed with the standard Lie-Poisson bracket admits polynomial integrable Hamiltonian systems. This conjecture was proved by S. T. Sadetov in 2003. Following his idea, we give an explicit geometric construction for commuting polynomials on g* and consider some examples. (This text is a revised version of my paper published in Russian: A. V. Bolsinov, Complete commutative families of polynomials in Poisson–Lie algebras: A proof of the Mischenko–Fomenko conjecture in book: Tensor and Vector Analysis, Vol. 26, Moscow State University, 2005, 87–109.

  16. Commuting to work: RN travel time to employment in rural and urban areas.

    Science.gov (United States)

    Rosenberg, Marie-Claire; Corcoran, Sean P; Kovner, Christine; Brewer, Carol

    2011-02-01

    To investigate the variation in average daily travel time to work among registered nurses (RNs) living in urban, suburban, and rural areas. We examine how travel time varies across RN characteristics, job setting, and availability of local employment opportunities. Descriptive statistics and linear regression using a 5% sample from the 2000 Census and a longitudinal survey of newly licensed RNs (NLRN). Travel time for NLRN respondents was estimated using geographic information systems (GIS) software. In the NLRN, rural nurses and those living in small towns had significantly longer average commute times. Young married RNs and RNs with children also tended to have longer commute times, as did RNs employed by hospitals. The findings indicate that travel time to work varies significantly across locale types. Further research is needed to understand whether and to what extent lengthy commute times impact RN workforce needs in rural and urban areas.

  17. The Association between Access to Public Transportation and Self-Reported Active Commuting

    DEFF Research Database (Denmark)

    Djurhuus, Sune; Hansen, Henning S; Aadahl, Mette

    2014-01-01

    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...... 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......-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...

  18. Accounting for the Theory of Planned Behaviour in departure time choice

    DEFF Research Database (Denmark)

    Thorhauge, Mikkel; Haustein, Sonja; Cherchi, Elisabetta

    2016-01-01

    choice. So far departure time choice modelling focussed mainly on objective factors, such as time and costs as main behavioural determinants. In this study, we derived psychological factors based on the Theory of Planned Behaviour, estimated them based on structural equation modelling, and included them......Motivating people to change their departure time could play a key role in reducing peakhour congestion, which remains one of the most prevalent transport problems in large urban areas. To achieve this behavioural change, it is necessary to better understand the factors that influence departure time...... into a discrete choice model. The psychological factors were measured based on an online questionnaire addressed to car commuters to the city centre of Copenhagen (N = 286). The questionnaire additionally included a travel diary and a stated preference experiment with nine departure time choice scenarios. All...

  19. Choice probability generating functions

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; McFadden, Daniel; Bierlaire, Michel

    2013-01-01

    This paper considers discrete choice, with choice probabilities coming from maximization of preferences from a random utility field perturbed by additive location shifters (ARUM). Any ARUM can be characterized by a choice-probability generating function (CPGF) whose gradient gives the choice...... probabilities, and every CPGF is consistent with an ARUM. We relate CPGF to multivariate extreme value distributions, and review and extend methods for constructing CPGF for applications. The choice probabilities of any ARUM may be approximated by a cross-nested logit model. The results for ARUM are extended...

  20. Entry Mode and Performance of Nordic Firms

    DEFF Research Database (Denmark)

    Wulff, Jesper

    2015-01-01

    This study investigates whether the relationship between mode of international market entry and non-location bound international experience is weaker for firms that are large or have a high foreign to total sales ratio, labeled multinational experience. Empirical evidence based on 250 foreign...... market entries made by Norwegian, Danish and Swedish firms suggests that the association between equity mode choice and non-location bound international experience diminishes in the presence of higher levels of multinational experience. Furthermore, firms whose entry mode choice is predicted by the model...