Science.gov

Sample records for current commutators

  1. Soft-commutated direct current motor

    DOEpatents

    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.

  2. Soft-commutated direct current motor

    DOEpatents

    Hsu, John S.

    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.

  3. FET commutated current-FED inverter

    NASA Technical Reports Server (NTRS)

    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.

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

    SciTech Connect

    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.

  5. Commuter rail state-of-the-art: A study of current systems. Final report

    SciTech Connect

    Shen, L.D.; Wu, J.W.

    1992-12-01

    The report documents the results of the state-of-the-art study on current commuter rail systems in the United States. Detailed information on operations, fare collection, stations, maintenance facilities, patronage, railcars, and feeder systems are presented. This commuter rail report is intended to provide a database of actual operation statistics for the 12 commuter rail systems in the United States. Statistics were collected on existing commuter rail services through Federal Transit Administration (FTA) reports, American Public Transit Association (APTA) and railroad industry publications. In addition, a survey was also conducted to collect the pertinent information on existing systems. A comparative analysis of commuter rail service with respect to other mass transit systems was conducted. New and proposed systems are also discussed. Current trends in commuter rail operations are presented. Startup costs for new systems were analyzed. This report found that many cities are considering commuter rail as a potential part of the solution to local transportation problems.

  6. Current-bounded commutation of a long-stroke magnetically levitated stage with moving coils

    NASA Astrophysics Data System (ADS)

    Zhu, Yu; Zhang, Shengguo; Yang, Kaiming; Mu, Haihua; Yin, Wensheng

    2012-11-01

    Magnetically levitated stages(MLS) have potentials to obtain good motion performances in high vacuum environment. Yet the electromagnetic forces/torques corresponding to six degrees of freedom(DOF) motions have coupling relationship with each current of coil array, and this coupling is still associated with the relative positions between the mover and the stator of the stage. So it is quite difficult to control the 6-DOF motions of the stage. By reasonable commutation of coil array, this complicated coupling relationship can be decoupled. The analytical force/torque-decomposing model of the stage is established first. Then the initial currents of coil array are commutated based on the pseudo inverse of the analytical force/torque-decomposing model matrix. And then the coil array currents are commutated again with different current bounds given to the initial currents as well as in the sense of minimum 2-norm of currents vector. Using the long stroke magnetically levitated stage with moving coils under investigation as examples, the currents of coil array are commutated with different current bounds adopting the proposed commutation method, the determination of current bound and the current bounds' influences on the heat-losses in coil array are analyzed, and the effectiveness of implementation algorithm of proposed commutation method is discussed. Simulation, analysis and discussion results indicate that the currents of coil array within the given current bound can be solved analytically by proposed commutation method, and the implementation algorithm does not need any searching or iteration. By the current-bounded commutation method proposed, the amplitude of coil array currents can be limited within an appropriate current bound(This is very beneficial to the improvement of the reliability and motion performance of the stage), as well as these currents can also generate the desired forces and torques.

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

    DOEpatents

    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.

  8. [Impact of commuting on partnership and family life. A literature review of the current state of research with special emphasis on commuter marriages].

    PubMed

    Häfner, Steffen

    2011-01-01

    Because of modern working conditions, for many people commuting has increasingly become a necessity with many consequences for their health as well as for their family life and partnership. To date, little research has been done concerning the impact of this modern lifestyle on partnership and family life, particularly on dual-career couples and long-distance commuters. The results of a literature review are presented based on age, sex, family cycle and consequences for children; research questions are formulated. Sex-specific differences seem to be especially important, confirming the "household responsibility hypothesis." The commuter marriage as a new lifestyle seems to have become a coping mechanism for the increasing necessity in our society to commute.

  9. Making almost commuting matrices commute

    SciTech Connect

    Hastings, Matthew B

    2008-01-01

    Suppose two Hermitian matrices A, B almost commute ({parallel}[A,B]{parallel} {<=} {delta}). Are they close to a commuting pair of Hermitian matrices, A', B', with {parallel}A-A'{parallel},{parallel}B-B'{parallel} {<=} {epsilon}? A theorem of H. Lin shows that this is uniformly true, in that for every {epsilon} > 0 there exists a {delta} > 0, independent of the size N of the matrices, for which almost commuting implies being close to a commuting pair. However, this theorem does not specifiy how {delta} depends on {epsilon}. We give uniform bounds relating {delta} and {epsilon}. The proof is constructive, giving an explicit algorithm to construct A' and B'. We provide tighter bounds in the case of block tridiagonal and tridiagnonal matrices. Within the context of quantum measurement, this implies an algorithm to construct a basis in which we can make a projective measurement that approximately measures two approximately commuting operators simultaneously. Finally, we comment briefly on the case of approximately measuring three or more approximately commuting operators using POVMs (positive operator-valued measures) instead of projective measurements.

  10. Leakage current and commutation losses reduction in electric drives for Hybrid Electric Vehicle

    NASA Astrophysics Data System (ADS)

    Miliani, El Hadj

    2014-06-01

    Nowadays, leakage current and inverter losses, produced by adjustable-speed AC drive systems become one of the main interested subject for researchers on Electric Vehicle (EV) and Hybrid Electric Vehicle (HEV) technology. The continuous advancements in solid state device engineering have considerably minimized the switching transients for power switches but the high dv/dt and high switching frequency have caused many adverse effects such as shaft voltage, bearing current, leakage current and electromagnetic interference (EMI). The major objective of this paper is to investigate and suppress of the adverse effects of a PWM inverter feeding AC motor in EV and HEV. A technique to simultaneously reduce the leakage current and the switching losses is presented in this paper. Based on a discontinuous space vector pulse width modulation (DSVPWM) and a modular switches gate resistance, inverter losses and leakage current are reduced. Algorithms are presented and implemented on a DSP controller and experimental results are presented.

  11. Commutation circuit for an HVDC circuit breaker

    DOEpatents

    Premerlani, W.J.

    1981-11-10

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components. 13 figs.

  12. Commutation circuit for an HVDC circuit breaker

    DOEpatents

    Premerlani, William J.

    1981-01-01

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components.

  13. Commutating Permanent-Magnet Motors At Low Speed

    NASA Technical Reports Server (NTRS)

    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.

  14. Electromagnetic Gun With Commutated Coils

    NASA Technical Reports Server (NTRS)

    Elliott, David G.

    1991-01-01

    Proposed electromagnetic gun includes electromagnet coil, turns of which commutated in sequence along barrel. Electrical current fed to two armatures by brushes sliding on bus bars in barrel. Interaction between armature currents and magnetic field from coil produces force accelerating armature, which in turn, pushes on projectile. Commutation scheme chosen so magnetic field approximately coincides and moves with cylindrical region defined by armatures. Scheme has disadvantage of complexity, but in return, enables designer to increase driving magnetic field without increasing armature current. Attainable muzzle velocity increased substantially.

  15. Minimum gate trigger current degradation in 4.5 kV 4H-SiC commutated gate turn-off thyristor

    NASA Astrophysics Data System (ADS)

    Nakayama, Koji; Tanaka, Atsushi; Ogata, Shuji; Izumi, Toru; Hayashi, Toshihiko; Asano, Katsunori

    2014-04-01

    The increment in minimum gate trigger current in a 4H-SiC commutated gate turn-off thyristor after the current stress test is investigated. The recombination at the intersection line of the Shockley-type stacking faults and the pn junction causes a reduction in the level of carrier injection from the anode to the gate. The current gain of the top pnp bipolar junction transistor, therefore, decreases, and the minimum gate trigger current increases. The minimum gate trigger current after the current stress test does not return to that before the current stress test at 200 °C, although the on-state voltage of the degraded thyristor returns to that of the original one when the temperature is increased to more than 150 °C. The Shockley-type stacking faults, which are parallel to the current flow from the anode to the gate and cause the increment in minimum gate trigger current, exist even if the temperature increases.

  16. Active commuting to school

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Declines in physical activity levels have coincided with increasing rates of obesity in children. This is problematic because physical activity has been shown to attenuate weight gain in children. Active commuting to school is one way of increasing children's physical activity. However, given the hi...

  17. Connecting with Commuters

    ERIC Educational Resources Information Center

    Ullman, Ellen

    2011-01-01

    For the last few years, Georgia State University has taken steps toward becoming a more traditional college instead of a commuter school. It bought two Atlanta hotels to be used as residence halls, started a football team, and is building townhouses for Greek fraternities and sororities. "When alumni come back to campus, they are shocked at all…

  18. Probing deformed quantum commutators

    NASA Astrophysics Data System (ADS)

    Rossi, Matteo A. C.; Giani, Tommaso; Paris, Matteo G. A.

    2016-07-01

    Several quantum gravity theories predict a minimal length at the order of magnitude of the Planck length, under which the concepts of space and time lose their physical meaning. In quantum mechanics, the insurgence of such a minimal length can be described by introducing a modified position-momentum commutator, which in turn yields a generalized uncertainty principle, where the uncertainty on position measurements has a lower bound. The value of the minimal length is not predicted by theories and must be estimated experimentally. In this paper, we address the quantum bound to the estimability of the minimal uncertainty length by performing measurements on a harmonic oscillator, which is analytically solvable in the deformed algebra induced by the deformed commutation relations.

  19. Radar channel balancing with commutation

    SciTech Connect

    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.

  20. Electronically commutated serial-parallel switching for motor windings

    DOEpatents

    Hsu, John S.

    2012-03-27

    A method and a circuit for controlling an ac machine comprises controlling a full bridge network of commutation switches which are connected between a multiphase voltage source and the phase windings to switch the phase windings between a parallel connection and a series connection while providing commutation discharge paths for electrical current resulting from inductance in the phase windings. This provides extra torque for starting a vehicle from lower battery current.

  1. Gate drive latching circuit for an auxiliary resonant commutation circuit

    NASA Technical Reports Server (NTRS)

    Delgado, Eladio Clemente (Inventor); Kheraluwala, Mustansir Hussainy (Inventor)

    1999-01-01

    A gate drive latching circuit for an auxiliary resonant commutation circuit for a power switching inverter includes a current monitor circuit providing a current signal to a pair of analog comparators to implement latching of one of a pair of auxiliary switching devices which are used to provide commutation current for commutating switching inverters in the circuit. Each of the pair of comparators feeds a latching circuit which responds to an active one of the comparators for latching the associated gate drive circuit for one of the pair of auxiliary commutating switches. An initial firing signal is applied to each of the commutating switches to gate each into conduction and the resulting current is monitored to determine current direction and therefore the one of the switches which is carrying current. The comparator provides a latching signal to the one of the auxiliary power switches which is actually conducting current and latches that particular power switch into an on state for the duration of current through the device. The latching circuit is so designed that the only time one of the auxiliary switching devices can be latched on is during the duration of an initial firing command signal.

  2. Gravity from a modified commutator

    SciTech Connect

    Jackson, Mark G.; /Fermilab

    2005-05-01

    We show that a suitably chosen position-momentum commutator can elegantly describe many features of gravity, including the IR/UV correspondence and dimensional reduction (''holography''). Using the most simplistic example based on dimensional analysis of black holes, we construct a commutator which qualitatively exhibits these novel properties of gravity. Dimensional reduction occurs because the quanta size grow quickly with momenta, and thus cannot be ''packed together'' as densely as naively expected. We conjecture that a more precise form of this commutator should be able to quantitatively reproduce all of these features.

  3. Commuting projections on graphs

    SciTech Connect

    Vassilevski, Panayot S.; Zikatanov, Ludmil T.

    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.

  4. Non-commutative tools for topological insulators

    NASA Astrophysics Data System (ADS)

    Prodan, Emil

    2010-06-01

    This paper reviews several analytic tools for the field of topological insulators, developed with the aid of non-commutative calculus and geometry. The set of tools includes bulk topological invariants defined directly in the thermodynamic limit and in the presence of disorder, whose robustness is shown to have nontrivial physical consequences for the bulk states. The set of tools also includes a general relation between the current of an observable and its edge index, a relation that can be used to investigate the robustness of the edge states against disorder. The paper focuses on the motivations behind creating such tools and on how to use them.

  5. Effects of Automobile Commute Characteristics on Affect and Job Candidate Evaluations: A Field Experiment

    ERIC Educational Resources Information Center

    Van Rooy, David L.

    2006-01-01

    The current study assesses the effects of the commuting environment on affective states and hiring decisions. A total of 136 undergraduate females were randomly assigned to one of four conditions based on the length (10 km vs. 30 km) and level of congestion (low vs. high) during a commute. Multivariate analyses of variance indicate that affective…

  6. Commuting Patterns of Nonmetro Household Heads, 1975.

    ERIC Educational Resources Information Center

    Bowles, Gladys K.; Beale, Calvin L.

    Data from the Annual Housing Survey indicated that 22% of all employed United States household heads commuted to a county different from that in which they lived in 1975. Commuting was more prevalent among men than among women and slightly higher for whites than for Blacks. Commuting tended to increase until age 25-34 and then to decline after age…

  7. 8 CFR 211.5 - Alien commuters.

    Code of Federal Regulations, 2010 CFR

    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...

  8. 8 CFR 211.5 - Alien commuters.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 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...

  9. Street lighting disturbs commuting bats.

    PubMed

    Stone, Emma Louise; Jones, Gareth; Harris, Stephen

    2009-07-14

    Anthropogenic disturbance is a major cause of worldwide declines in biodiversity. Understanding the implications of this disturbance for species and populations is crucial for conservation biologists wishing to mitigate negative effects. Anthropogenic light pollution is an increasing global problem, affecting ecological interactions across a range of taxa and impacting negatively upon critical animal behaviors including foraging, reproduction, and communication (for review see). Almost all bats are nocturnal, making them ideal subjects for testing the effects of light pollution. Previous studies have shown that bat species adapted to foraging in open environments feed on insects attracted to mercury vapor lamps. Here, we use an experimental approach to provide the first evidence of a negative effect of artificial light pollution on the commuting behavior of a threatened bat species. We installed high-pressure sodium lights that mimic the intensity and light spectra of streetlights along commuting routes of lesser horseshoe bats (Rhinolophus hipposideros). Bat activity was reduced dramatically and the onset of commuting behavior was delayed in the presence of lighting, with no evidence of habituation. These results demonstrate that light pollution may have significant negative impacts upon the selection of flight routes by bats. PMID:19540116

  10. Happiness and Satisfaction with Work Commute.

    PubMed

    Olsson, Lars E; Gärling, Tommy; Ettema, Dick; Friman, Margareta; Fujii, Satoshi

    2013-03-01

    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 satisfaction with the work commute contributes to overall happiness. It is also found that feelings during the commutes are predominantly positive or neutral. Possible explanatory factors include desirable physical exercise from walking and biking, as well as that short commutes provide a buffer between the work and private spheres. For longer work commutes, social and entertainment activities either increase positive affects or counteract stress and boredom. Satisfaction with being employed in a recession may also spill over to positive experiences of work commutes. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11205-012-0003-2) contains supplementary material, which is available to authorized users.

  11. An Assessment of Commuter Aircraft Noise Impact

    NASA Technical Reports Server (NTRS)

    Fidell, Sanford; Pearsons, Karl S.; Silvati, Laura; Sneddon, Matthew

    1996-01-01

    This report examines several approaches to understanding 'the commuter aircraft noise problem.' The commuter aircraft noise problem in the sense addressed in this report is the belief that some aspect(s) of community response to noise produced by commuter aircraft operations may not be fully assessed by conventional environmental noise metrics and methods. The report offers alternate perspectives and approaches for understanding this issue. The report also develops a set of diagnostic screening questions; describes commuter aircraft noise situations at several airports; and makes recommendations for increasing understanding of the practical consequences of greater heterogeneity in the air transport fleet serving larger airports.

  12. Imprecise probability for non-commuting observables

    NASA Astrophysics Data System (ADS)

    Allahverdyan, Armen E.

    2015-08-01

    It is known that non-commuting observables in quantum mechanics do not have joint probability. This statement refers to the precise (additive) probability model. I show that the joint distribution of any non-commuting pair of variables can be quantified via upper and lower probabilities, i.e. the joint probability is described by an interval instead of a number (imprecise probability). I propose transparent axioms from which the upper and lower probability operators follow. The imprecise probability depend on the non-commuting observables, is linear over the state (density matrix) and reverts to the usual expression for commuting observables.

  13. Detroit Commuter Hydrogen Project

    SciTech Connect

    Brooks, Jerry; Prebo, Brendan

    2010-07-31

    This project was undertaken to demonstrate the viability of using hydrogen as a fuel in an internal combustion engine vehicle for use as a part of a mass transit system. The advantages of hydrogen as a fuel include renew-ability, minimal environmental impact on air quality and the environment, and potential to reduce dependence on foreign energy sources for the transportation sector. Recognizing the potential for the hydrogen fuel concept, the Southeast Michigan Congress of Governments (SEMCOG) determined to consider it in the study of a proposed regional mass transit rail system for southeast Michigan. SEMCOG wanted to evaluate the feasibility of using hydrogen fueled internal combustion engine (H2ICE) vehicles in shuttle buses to connect the Detroit Metro Airport to a proposed, nearby rail station. Shuttle buses are in current use on the airport for passenger parking and inter-terminal transport. This duty cycle is well suited to the application of hydrogen fuel at this time because of the ability to re-fuel vehicles at a single nearby facility, overcoming the challenge of restricted fuel availability in the undeveloped hydrogen fuel infrastructure. A cooperative agreement between SEMCOG and the DOE was initiated and two H2ICE buses were placed in regular passenger service on March 29, 2009 and operated for six months in regular passenger service. The buses were developed and built by the Ford Motor Company. Wayne County Airport Authority provided the location for the demonstration with the airport transportation contractor, Metro Cars Inc. operating the buses. The buses were built on Ford E450 chassis and incorporated a modified a 6.8L V-10 engine with specially designed supercharger, fuel rails and injectors among other sophisticated control systems. Up to 30 kg of on-board gaseous hydrogen were stored in a modular six tank, 350 bar (5000 psi) system to provide a 150 mile driving range. The bus chassis and body were configured to carry nine passengers with

  14. Commutated automatic gain control system

    NASA Technical Reports Server (NTRS)

    Yost, S. R.

    1982-01-01

    A commutated automatic gain control (AGC) system was designed and built for a prototype Loran C receiver. The receiver uses a microcomputer to control a memory aided phase-locked loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The circuit designed for the AGC is described, and bench and flight test results are presented. The AGC circuit described actually samples starting at a point 40 microseconds after a zero crossing determined by the software lock pulse ultimately generated by a 30 microsecond delay and add network in the receiver front end envelope detector.

  15. Tsirelson's problem and asymptotically commuting unitary matrices

    SciTech Connect

    Ozawa, Narutaka

    2013-03-15

    In this paper, we consider quantum correlations of bipartite systems having a slight interaction, and reinterpret Tsirelson's problem (and hence Kirchberg's and Connes's conjectures) in terms of finite-dimensional asymptotically commuting positive operator valued measures. We also consider the systems of asymptotically commuting unitary matrices and formulate the Stronger Kirchberg Conjecture.

  16. Happiness and Satisfaction with Work Commute

    ERIC Educational Resources Information Center

    Olsson, Lars E.; Garling, Tommy; Ettema, Dick; Friman, Margareta; Fujii, Satoshi

    2013-01-01

    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 satisfaction with the work commute contributes to…

  17. 8 CFR 211.5 - Alien commuters.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... shall be made in accordance with 8 CFR 264.5. ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent...

  18. 8 CFR 211.5 - Alien commuters.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... shall be made in accordance with 8 CFR 264.5. ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent...

  19. 8 CFR 211.5 - Alien commuters.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... shall be made in accordance with 8 CFR 264.5. ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent...

  20. Commutated automatic gain control system

    NASA Technical Reports Server (NTRS)

    Yost, S. R.

    1981-01-01

    A commutated automatic gain control system (AGC) was designed and constructed for the prototype Loran C receiver. The AGC is designed to improve the signal-to-signal ratio of the received Loran signals. The AGC design does not require any analog to digital conversion and it utilizes commonly available components. The AGC consists of: (1) a circuit which samples the peak of the envelope of the Loran signal to obtain an AGC voltage for each of three Loran stations, (2) a dc gain circuit to control the overall gain of the AGC system, and (3) an AGC amplification of the input RF signal. The performance of the AGC system was observed in bench and flight tests; it has improved the overall accuracy of the receiver. Improvements in the accuracy of the time difference calculations to within approx. + or - 1.5 microseconds of the observed time differnces for a given position are reported.

  1. Fostering Formal Commutativity Knowledge with Approximate Arithmetic.

    PubMed

    Hansen, Sonja Maria; Haider, Hilde; Eichler, Alexandra; Godau, Claudia; Frensch, Peter A; Gaschler, Robert

    2015-01-01

    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. PMID:26560311

  2. Fostering Formal Commutativity Knowledge with Approximate Arithmetic

    PubMed Central

    Hansen, Sonja Maria; Haider, Hilde; Eichler, Alexandra; Godau, Claudia; Frensch, Peter A.; Gaschler, Robert

    2015-01-01

    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. PMID:26560311

  3. Planning for rotorcraft and commuter air transportationn

    NASA Technical Reports Server (NTRS)

    Stockwell, W. L.; Stowers, J.

    1981-01-01

    Community planning needs, criteria, and other considerations such as intermodal coordination and regulatory requirements, for rotorcraft and fixed wing commuter air transportation were identified. A broad range of community planning guidelines, issues, and information which can be used to: (1) direct anticipated aircraft technological improvements; (2) assist planners in identifying and evaluating the opportunities and tradeoffs presented by rotorcraft and commuter aircraft options relative to other modes; and (3) increase communication between aircraft technologists and planners for the purpose of on going support in capitalizing on rotorcraft and commuter air opportunities are provided. The primary tool for identifying and analyzing planning requirements was a detailed questionnaire administered to a selected sample of 55 community planners and other involved in planning for helicopters and commuter aviation.

  4. Non-commutativity measure of quantum discord

    NASA Astrophysics Data System (ADS)

    Guo, Yu

    2016-04-01

    Quantum discord is a manifestation of quantum correlations due to non-commutativity rather than entanglement. Two measures of quantum discord by the amount of non-commutativity via the trace norm and the Hilbert-Schmidt norm respectively are proposed in this paper. These two measures can be calculated easily for any state with arbitrary dimension. It is shown by several examples that these measures can reflect the amount of the original quantum discord.

  5. Extreme commutative quantum observables are sharp

    NASA Astrophysics Data System (ADS)

    Heinosaari, Teiko; Pellonpää, Juha-Pekka

    2011-08-01

    It is well known that, in the description of quantum observables, positive operator valued measures (POVMs) generalize projection valued measures (PVMs) and they also turn out be more optimal in many tasks. We show that a commutative POVM is an extreme point in the convex set of all POVMs if and only if it is a PVM. This results implies that non-commutativity is a necessary ingredient to overcome the limitations of PVMs.

  6. Non-commutativity measure of quantum discord

    PubMed Central

    Guo, Yu

    2016-01-01

    Quantum discord is a manifestation of quantum correlations due to non-commutativity rather than entanglement. Two measures of quantum discord by the amount of non-commutativity via the trace norm and the Hilbert-Schmidt norm respectively are proposed in this paper. These two measures can be calculated easily for any state with arbitrary dimension. It is shown by several examples that these measures can reflect the amount of the original quantum discord. PMID:27122226

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

    PubMed

    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.

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

    PubMed

    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. PMID:25129446

  9. Holographic charge transport in non commutative gauge theories

    NASA Astrophysics Data System (ADS)

    Roychowdhury, Dibakar

    2015-07-01

    In this paper, based on the holographic techniques, we explore the hydrodynamics of charge diffusion phenomena in non commutative SYM plasma at strong coupling. In our analysis, we compute the R charge diffusion rates both along commutative as well as the non commutative coordinates of the brane. It turns out that unlike the case for the shear viscosity, the DC conductivity along the non commutative direction of the brane differs significantly from that of its cousin corresponding to the commutative direction of the brane. Such a discrepancy however smoothly goes away in the limit of the vanishing non commutativity.

  10. Commuter, regional, and rail transit: research and analysis. Transportation Research Record

    SciTech Connect

    Not Available

    1988-01-01

    The 7 papers in this report deal with the following areas: evaluating the accessibility of commuter rail services: metro systemwide parking inventory/assessment; railrider - a comprehensive commuter rail forecasting mode; development of a rail-station choice model for NJ transit; characteristics of metro networks and methodology for their evaluation; attitudes and practices: direct-current transit systems and stray-current corrosion; Hoboken terminal: pedestrian planning for the twenty-first century; and staging-area simulation model for Seattle metro bus subway.

  11. Probing deformed commutators with macroscopic harmonic oscillators

    PubMed Central

    Bawaj, Mateusz; Biancofiore, Ciro; Bonaldi, Michele; Bonfigli, Federica; Borrielli, Antonio; Di Giuseppe, Giovanni; Marconi, Lorenzo; Marino, Francesco; Natali, Riccardo; Pontin, Antonio; Prodi, Giovanni A.; Serra, Enrico; Vitali, David; Marin, Francesco

    2015-01-01

    A minimal observable length is a common feature of theories that aim to merge quantum physics and gravity. Quantum mechanically, this concept is associated with a nonzero minimal uncertainty in position measurements, which is encoded in deformed commutation relations. In spite of increasing theoretical interest, the subject suffers from the complete lack of dedicated experiments and bounds to the deformation parameters have just been extrapolated from indirect measurements. As recently proposed, low-energy mechanical oscillators could allow to reveal the effect of a modified commutator. Here we analyze the free evolution of high-quality factor micro- and nano-oscillators, spanning a wide range of masses around the Planck mass mP (≈22 μg). The direct check against a model of deformed dynamics substantially lowers the previous limits on the parameters quantifying the commutator deformation. PMID:26088965

  12. Commutative Families of the Elliptic Macdonald Operator

    NASA Astrophysics Data System (ADS)

    Saito, Yosuke

    2014-03-01

    In the paper [J. Math. Phys. 50 (2009), 095215, 42 pages], Feigin, Hashizume, Hoshino, Shiraishi, and Yanagida constructed two families of commuting operators which contain the Macdonald operator (commutative families of the Macdonald operator). They used the Ding-Iohara-Miki algebra and the trigonometric Feigin-Odesskii algebra. In the previous paper [arXiv:1301.4912], the present author constructed the elliptic Ding-Iohara-Miki algebra and the free field realization of the elliptic Macdonald operator. In this paper, we show that by using the elliptic Ding-Iohara-Miki algebra and the elliptic Feigin-Odesskii algebra, we can construct commutative families of the elliptic Macdonald operator. In Appendix, we will show a relation between the elliptic Macdonald operator and its kernel function by the free field realization.

  13. Beating the traffic with commuting alternatives

    SciTech Connect

    1995-05-01

    This pamphlet describes how, by encouraging commuting options, local governments can help reduce air pollution, fuel consumption, and traffic congestion. Minimizing these problems makes the community more appealing to businesses, residents, and visitors and boosts the local economy. Approaches to alternative transportation are as varied as the communities devising and using them. But the critical factor is initiative from local governments, often one of communities largest employers. They can use and promote commuting alternatives among their employees. Local governments can also promote alternative transportation among other employers and the general public. They can provide information on commuting options, improve the infrastructure, and use local authority to require and reward those changes necessary to make alternative transportation a widely accepted part of community life. Best of all, local governments can lead by example and establish a template for other employers to follow.

  14. The Influence of Contact Space on Arc Commutation Process in Air Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Niu, Chunping; Ding, Juwen; Yang, Fei; Dong, Delong; Rong, Mingzhe; Xu, Dan

    2016-05-01

    In this paper, a 3D magneto-hydrodynamic (MHD) arc simulation model is applied to analyze the arc motion during current interruption in a certain air circuit breaker (ACB). The distributions of pressure, temperature, gas flow and current density of the arc plasma in the arc region are calculated, and the factors influencing the commutation process are analyzed according to the calculated results. Based on the airflow in the arc chamber, the causes of arc commutation asynchrony and the back commutation are investigated. It indicates that a reasonable contact space design is crucial to a successful arc commutation process. To verify the simulation results, the influence of contact space on arc voltage and arc commutation is tested. This research can provide methods and references to the optimization of ACB design. supported by National Key Basic Research Program of China (973 Program) (Nos. 2015CB251002, 6132620303) and National Natural Science Foundation of China (Nos. 51221005, 51377128, 51577144), and Science and Technology Project Through Grid State Corporation (No. SGSNKYOOKJJS1501564)

  15. Employees' Perceptions of Cycle Commuting: A Qualitative Study

    ERIC Educational Resources Information Center

    van Bekkum, Jennifer E.; Williams, Joanne M.; Morris, Paul Graham

    2011-01-01

    Purpose: This study aims to provide an in-depth individual level understanding of the psychological factors that affect cycle commuting. Design/methodology/approach: A total of 15 participants (eight cycle commuters and seven potential cycle commuters) from a "cycle-friendly" employer based in a Scottish city took part in the study.…

  16. Transport improvement, commuting costs, and residential location

    NASA Technical Reports Server (NTRS)

    Stucker, J. P.

    1973-01-01

    A theoretical framework for evaluating the effects of introducing new transportation on residential travel patterns is presented. Data are based on changes in residential location of urban commuters that alter the mode and length of work trips as well as economic factors.

  17. Quantum Gibbs Samplers: The Commuting Case

    NASA Astrophysics Data System (ADS)

    Kastoryano, Michael J.; Brandão, Fernando G. S. L.

    2016-06-01

    We analyze the problem of preparing quantum Gibbs states of lattice spin Hamiltonians with local and commuting terms on a quantum computer and in nature. Our central result is an equivalence between the behavior of correlations in the Gibbs state and the mixing time of the semigroup which drives the system to thermal equilibrium (the Gibbs sampler). We introduce a framework for analyzing the correlation and mixing properties of quantum Gibbs states and quantum Gibbs samplers, which is rooted in the theory of non-commutative {mathbb{L}_p} spaces. We consider two distinct classes of Gibbs samplers, one of them being the well-studied Davies generator modelling the dynamics of a system due to weak-coupling with a large Markovian environment. We show that their spectral gap is independent of system size if, and only if, a certain strong form of clustering of correlations holds in the Gibbs state. Therefore every Gibbs state of a commuting Hamiltonian that satisfies clustering of correlations in this strong sense can be prepared efficiently on a quantum computer. As concrete applications of our formalism, we show that for every one-dimensional lattice system, or for systems in lattices of any dimension at temperatures above a certain threshold, the Gibbs samplers of commuting Hamiltonians are always gapped, giving an efficient way of preparing the associated Gibbs states on a quantum computer.

  18. Nontraditional, Female, Commuter Students: Coping with College.

    ERIC Educational Resources Information Center

    Rogers, George W., Jr.

    The unique needs of nontraditional, female, commuter students at Northern Kentucky University were examined as a result of active recruitment of nontraditional students in the dwindling market for traditional college students. Women over the age of 25 are entering Northern Kentucky University, bringing unique personal and career problems. Problem…

  19. Propulsion opportunities for future commuter aircraft

    NASA Technical Reports Server (NTRS)

    Strack, W. C.

    1982-01-01

    Circa 1990 propulsion improvement concepts are discussed for 1000 to 5000 SHP conventional turboprop powerplants including engines, gearboxes, and propellers. Cycle selection, power plant configurations and advanced technology elements are defined and evaluated using average stage length DOC for commuter aircraft as the primary merit criterion.

  20. Class 2 design update for the family of commuter airplanes

    NASA Technical Reports Server (NTRS)

    Creighton, Thomas R.; Hendrich, Louis J.

    1987-01-01

    This is the final report of seven on the design of a family of commuter airplanes. This design effort was performed in fulfillment of NASA/USRA grant NGT-8001. Its contents are as follows: (1) the class 1 baseline designs for the commuter airplane family; (2) a study of takeoff weight penalties imposed on the commuter family due to implementing commonality objectives; (3) component structural designs common to the commuter family; (4) details of the acquisition and operating economics of the commuter family, i.e., savings due to production commonality and handling qualities commonality are determined; (5) discussion of the selection of an advanced turboprop propulsion system for the family of commuter airplanes, and (6) a proposed design for an SSSA controller design to achieve similar handling for all airplanes. Final class 2 commuter airplane designs are also presented.

  1. Size and seasonal distributions of airborne bioaerosols in commuting trains

    NASA Astrophysics Data System (ADS)

    Wang, Ya-Fen; Wang, Che-Hsu; Hsu, Kai-Lin

    2010-11-01

    Aerobiological studies in commuting trains in northern Taiwan were carried out from August, 2007 until July, 2008. Two six-stage (>7 μm, 4.7˜7 μm, 3.3˜4.7 μm, 2.1˜3.3 μm, 1.1˜2.1 μm, 0.65˜1.1 μm) cascade impactors of 400 orifices were used to collect viable bacteria and fungi, respectively. The levels of carbon monoxide (CO), carbon dioxide (CO 2), formaldehyde (HCHO), temperature, and relative humidity in the commuting trains were also recorded during the sampling period. Results show that bacterial concentrations ranged from 25 to 1530 CFU m -3, and averaged 417 CFU m -3. The fungal concentrations ranged from 45 to 1906 CFU m -3, and averaged 413 CFU m -3. Additionally, the highest fractions occurred in the fifth stage (1.1˜2.1 μm) for both bacteria and fungi. The respirable fractions, Rb and Rf, for bacteria and fungi were 62.8% and 81.4%, respectively, which are higher than those in other studies. Furthermore, the bacterial concentration reached its highest level in autumn, and its lowest level in winter. However, the fungal concentration was highest in spring and lowest in winter. Though the total bacterial or fungal concentration did not exceed the recommendation standard in Taiwan, the relatively high respirable fraction in commuting trains probably implies a higher adverse health risk for sensitive commuters. This study further conducted multiple regression analysis to determine the relationship of various stage fractions of airborne bacteria and fungi with indoor air pollutants (CO and HCHO) and environmental parameters (CO 2, temperature, and relative humidity). The correlation coefficients of multiple regression analysis for total bacteria and fungi concentrations with indoor air pollutants and environmental parameters were 0.707 ( p < 0.00376) and 0.612 ( p < 0.00471), respectively. There are currently no formally regulated laws for indoor air quality (IAQ) in Taiwan, and this preliminary study can provide references to the Taiwan

  2. Quantifying commuter exposures to volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Kayne, Ashleigh

    Motor-vehicles can be a predominant source of air pollution in cities. Traffic-related air pollution is often unavoidable for people who live in populous areas. Commuters may have high exposures to traffic-related air pollution as they are close to vehicle tailpipes. Volatile organic compounds (VOCs) are one class of air pollutants of concern because exposure to VOCs carries risk for adverse health effects. Specific VOCs of interest for this work include benzene, toluene, ethylbenzene, and xylenes (BTEX), which are often found in gasoline and combustion products. Although methods exist to measure time-integrated personal exposures to BTEX, there are few practical methods to measure a commuter's time-resolved BTEX exposure which could identify peak exposures that could be concealed with a time-integrated measurement. This study evaluated the ability of a photoionization detector (PID) to measure commuters' exposure to BTEX using Tenax TA samples as a reference and quantified the difference in BTEX exposure between cyclists and drivers with windows open and closed. To determine the suitability of two measurement methods (PID and Tenax TA) for use in this study, the precision, linearity, and limits of detection (LODs) for both the PID and Tenax TA measurement methods were determined in the laboratory with standard BTEX calibration gases. Volunteers commuted from their homes to their work places by cycling or driving while wearing a personal exposure backpack containing a collocated PID and Tenax TA sampler. Volunteers completed a survey and indicated if the windows in their vehicle were open or closed. Comparing pairs of exposure data from the Tenax TA and PID sampling methods determined the suitability of the PID to measure the BTEX exposures of commuters. The difference between BTEX exposures of cyclists and drivers with windows open and closed in Fort Collins was determined. Both the PID and Tenax TA measurement methods were precise and linear when evaluated in the

  3. Factors Affecting Consumers' Green Commuting

    ERIC Educational Resources Information Center

    Kai, Chen; Haokai, Liang

    2016-01-01

    As Chinese air pollution and other environmental problems were paid much attention by the public, appeals about reducing private car use and adopting public transport had come into being. In view of this context, the current study extended the theory of planned behavior by including environmental concerns to explore the effect of subjective…

  4. Vehicle emissions during children's school commuting: impacts of education policy.

    PubMed

    Marshall, Julian D; Wilson, Ryan D; Meyer, Katie L; Rajangam, Santhosh K; McDonald, Noreen C; Wilson, Elizabeth J

    2010-03-01

    We explore how school policies influence the environmental impacts of school commutes. Our research is motivated by increased interest in school choice policies (in part because of the U.S. "No Child Left Behind" Act) and in reducing bus service to address recent budget shortfalls. Our analysis employs two samples of elementary-age children, age 5-12: a travel survey (n = 1246 respondents) and a school enrollment data set (n = 19,655 students). Multinomial logistic regression modeled the determinants of travel mode (automobile, school bus, and walking; n = 803 students meeting selection criteria). Travel distance has the single greatest effect on travel mode, though school choice, trip direction (to- or from-school), and grade play a role. Several policies were investigated quantitatively to predict the impact on school travel, vehicle emissions, and costs. We find that eliminating district-wide school choice (i.e., returning to a system with neighborhood schools only) would have significant impacts on transport modes and emissions, whereas in many cases proposed shifts in school choice and bus-provision policies would have only modest impacts. Policies such as school choice and school siting may conflict with the goal of increasing rates of active (i.e., nonmotorized) school commuting. Policies that curtail bus usage may reduce bus emissions but yield even larger increases in private-vehicle emissions. Our findings underscore the need to critically evaluate transportation-related environmental and health impacts of currently proposed changes in school policy.

  5. Mapping commuter cycling risk in urban areas.

    PubMed

    Yiannakoulias, Nikolaos; Bennet, Scott A; Scott, Darren M

    2012-03-01

    Cycling is becoming an increasingly important transportation option for commuters. Cycling offers exercise opportunities and reduces the burden of motor vehicle travel on society. Mapping the risk of collision between cyclists and motor vehicles in urban areas is important to understanding safe cyclist route opportunities, making informed transportation planning decisions, and exploring patterns of injury epidemiology. To date, many geographic analyses and representations of cyclist risk have not taken the concept of exposure into account. Instead, risk is either expressed as a rate per capita, or as a count of events. Using data associated with the City of Hamilton, Canada, we illustrate a method for mapping commuter cyclist collision risk per distance travelled. This measure can be used to more realistically represent the underlying geography of cycling risk, and provide more geographically and empirically meaningful information to those interested in understanding how cycling safety varies over space. PMID:22269497

  6. Mapping commuter cycling risk in urban areas.

    PubMed

    Yiannakoulias, Nikolaos; Bennet, Scott A; Scott, Darren M

    2012-03-01

    Cycling is becoming an increasingly important transportation option for commuters. Cycling offers exercise opportunities and reduces the burden of motor vehicle travel on society. Mapping the risk of collision between cyclists and motor vehicles in urban areas is important to understanding safe cyclist route opportunities, making informed transportation planning decisions, and exploring patterns of injury epidemiology. To date, many geographic analyses and representations of cyclist risk have not taken the concept of exposure into account. Instead, risk is either expressed as a rate per capita, or as a count of events. Using data associated with the City of Hamilton, Canada, we illustrate a method for mapping commuter cyclist collision risk per distance travelled. This measure can be used to more realistically represent the underlying geography of cycling risk, and provide more geographically and empirically meaningful information to those interested in understanding how cycling safety varies over space.

  7. A study of commuter airplane design optimization

    NASA Technical Reports Server (NTRS)

    Roskam, J.; Wyatt, R. D.; Griswold, D. A.; Hammer, J. L.

    1977-01-01

    Problems of commuter airplane configuration design were studied to affect a minimization of direct operating costs. Factors considered were the minimization of fuselage drag, methods of wing design, and the estimated drag of an airplane submerged in a propellor slipstream; all design criteria were studied under a set of fixed performance, mission, and stability constraints. Configuration design data were assembled for application by a computerized design methodology program similar to the NASA-Ames General Aviation Synthesis Program.

  8. A study of commuter air service

    NASA Technical Reports Server (NTRS)

    Belina, F. W.; Bush, L. R.

    1977-01-01

    A regionally oriented overview of the commuter air service industry is provided. A framework for an eventual assessment of potential technology directions that may be of benefit to the industry is presented. Data are provided on the industry's market characteristics, service patterns, patronage characteristics, aircraft and airport needs, economic characteristics and institutional issues. Using personal interview and literature survey methods, investigation of a considerable cross-section of the industry was made.

  9. Ride quality systems for commuter aircraft

    NASA Technical Reports Server (NTRS)

    Downing, D. R.; Hammond, T. A.; Amin, S. P.

    1983-01-01

    The state-of-the-art in Active Ride Augmentation, specifically in terms of its feasibility for commuter aircraft applications. A literature survey was done, and the principal results are presented here through discussion of different Ride Quality Augmentation System (RQAS) designs and advances in related technologies. Recommended follow-on research areas are discussed, and a preliminary RQAS configuration for detailed design and development is proposed.

  10. p-adic commutation relations

    NASA Astrophysics Data System (ADS)

    Kochubei, Anatoly N.

    1996-10-01

    Representations of the canonical and deformed commutation relations by bounded operators on p-adic Banach spaces are constructed. Functions from the Mahler basis of the space of p-adic continuous functions and their multiplicative analogues are shown to be the p-adic counterparts of the Hermite and q-Hermite functions. The analogue of the Stone - von Neumann uniqueness theorem fails in the p-adic case.

  11. Quantifying commuter exposures to volatile organic compounds

    NASA Astrophysics Data System (ADS)

    Kayne, Ashleigh

    Motor-vehicles can be a predominant source of air pollution in cities. Traffic-related air pollution is often unavoidable for people who live in populous areas. Commuters may have high exposures to traffic-related air pollution as they are close to vehicle tailpipes. Volatile organic compounds (VOCs) are one class of air pollutants of concern because exposure to VOCs carries risk for adverse health effects. Specific VOCs of interest for this work include benzene, toluene, ethylbenzene, and xylenes (BTEX), which are often found in gasoline and combustion products. Although methods exist to measure time-integrated personal exposures to BTEX, there are few practical methods to measure a commuter's time-resolved BTEX exposure which could identify peak exposures that could be concealed with a time-integrated measurement. This study evaluated the ability of a photoionization detector (PID) to measure commuters' exposure to BTEX using Tenax TA samples as a reference and quantified the difference in BTEX exposure between cyclists and drivers with windows open and closed. To determine the suitability of two measurement methods (PID and Tenax TA) for use in this study, the precision, linearity, and limits of detection (LODs) for both the PID and Tenax TA measurement methods were determined in the laboratory with standard BTEX calibration gases. Volunteers commuted from their homes to their work places by cycling or driving while wearing a personal exposure backpack containing a collocated PID and Tenax TA sampler. Volunteers completed a survey and indicated if the windows in their vehicle were open or closed. Comparing pairs of exposure data from the Tenax TA and PID sampling methods determined the suitability of the PID to measure the BTEX exposures of commuters. The difference between BTEX exposures of cyclists and drivers with windows open and closed in Fort Collins was determined. Both the PID and Tenax TA measurement methods were precise and linear when evaluated in the

  12. Can Walking or Biking to Work Really Make a Difference? Compact Development, Observed Commuter Choice and Body Mass Index

    PubMed Central

    Wojan, Timothy R.; Hamrick, Karen S.

    2015-01-01

    Objectives Promoting active commuting is viewed as one strategy to increase physical activity and improve the energy balance of more sedentary individuals thereby improving health outcomes. However, the potential effectiveness of promotion policies may be seriously undermined by the endogenous choice of commute mode. Policy to promote active commuting will be most effective if it can be demonstrated that 1) those in compact cities do not necessarily have a preference for more physical activity, and 2) that current active commuting is not explained by unobserved characteristics that may be the true source of a lower body mass index (BMI). Methods Daily time-use diaries are used in combination with geographical characteristics of where respondents live and work to test 1) whether residents of more compact settlements are characterized by higher activity levels; and 2) whether residents of more compact settlements are more likely to bike or walk to work. An endogenous treatment model of active commuting allows testing whether reductions in BMI associated with walking or biking to work are in fact attributable to that activity or are more strongly associated with unobserved characteristics of these active commuters. Results The analysis of general activity levels confirms that residents of more compact cities do not expend more energy than residents of more sprawling cities, indicating that those in compact cities do not necessarily have a preference for more physical activity. The endogenous treatment model is consistent with walking or biking to work having an independent effect on BMI, as unobserved factors that contribute to a higher likelihood of active commuting are not associated with lower BMI. Conclusions Despite evidence that more compact settlement patterns enable active commuting, only a small share of workers in these areas choose to walk or bike to work. In general, the activity level of residents in more compact cities and residents in more sprawling

  13. Commuting simplicity and closure constraints for 4D spin-foam models

    NASA Astrophysics Data System (ADS)

    Han, Muxin; Thiemann, Thomas

    2013-12-01

    Spin-foam models are supposed to be discretized path integrals for quantum gravity constructed from the Plebanski-Holst action. The reason for there being several models currently under consideration is that no consensus has been reached for how to implement the simplicity constraints. Indeed, none of these models strictly follows from the original path integral with commuting B fields, rather, by some nonstandard manipulations one always ends up with non-commuting B fields and the simplicity constraints become in fact anomalous which is the source for there being several inequivalent strategies to circumvent the associated problems. In this paper, we construct a new Euclidian spin-foam model which is constructed by standard methods from the Plebanski-Holst path integral with commuting B fields discretized on a 4D simplicial complex. The resulting model differs from the current ones in several aspects, one of them being that the closure constraint needs special care. Only when dropping the closure constraint by hand and only in the large spin limit can the vertex amplitudes of this model be related to those of the FKγ model but even then the face and edge amplitude differ. Interestingly, a non-commutative deformation of the BIJ variables leads from our new model to the Barrett-Crane model in the case of γ = ∞.

  14. Battery cars on superconducting magnetically levitated carriers: One commuting solution

    NASA Technical Reports Server (NTRS)

    Briggs, B. Mike; Oman, Henry

    1992-01-01

    Commuting to work in an urban-suburban metropolitan environment is becoming an unpleasant time-wasting process. We applied the technology of communication management to this commuting problem. Communication management is a system-engineering tool that produced today's efficient telephone network. The resulting best commuting option is magnetically levitated carriers of two-passenger, battery-powered, personally-owned local-travel cars. A commuter drives a car to a nearby station, selects a destination, drives on a waiting carrier, and enters an accelerating ramp. A central computer selects an optimum 100 miles-per-hour trunk route, considering existing and forecast traffic; assigns the commuter a travel slot, and subsequently orders switching-station actions. The commuter uses the expensive facilities for only a few minutes during each trip. The cost of travel could be less than 6 cents per mile.

  15. Exposure of commuters to volatile aromatic hydrocarbons from petrol exhaust.

    PubMed

    Löfgren, L; Persson, K; Strömvall, A M; Petersson, G

    1991-10-15

    Twenty-two volatile aromatic hydrocarbons were determined in the air of an automobile during commuting. Sampling was made on Tenax cartridges and laboratory determinations were carried out using thermal desorption combined with temperature-programmed capillary gas chromatography. Selected hydrocarbons representative of petrol exhaust were determined in the automobile and in an electric commuter train during eight parallel commuter trips. In the automobile, the concentrations of benzene were 35-70 micrograms/m3 and those of total aromatic hydrocarbons 200-400 micrograms/m3. The petrol exhaust levels were 5-10 times higher in the automobile than in the compartment of the commuter train.

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

    NASA Astrophysics Data System (ADS)

    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

  17. Shock Waves and Commutation Speed of Memristors

    NASA Astrophysics Data System (ADS)

    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.

  18. Bicycle weight and commuting time: randomised trial

    PubMed Central

    2010-01-01

    Objective To determine whether the author’s 20.9 lb (9.5 kg) carbon frame bicycle reduced commuting time compared with his 29.75 lb (13.5 kg) steel frame bicycle. Design Randomised trial. Setting Sheffield and Chesterfield, United Kingdom, between mid-January 2010 and mid-July 2010. Participants One consultant in anaesthesia and intensive care. Main outcome measure Total time to complete the 27 mile (43.5 kilometre) journey from Sheffield to Chesterfield Royal Hospital and back. Results The total distance travelled on the steel frame bicycle during the study period was 809 miles (1302 km) and on the carbon frame bicycle was 711 miles (1144 km). The difference in the mean journey time between the steel and carbon bicycles was 00:00:32 (hr:min:sec; 95% CI –00:03:34 to 00:02:30; P=0.72). Conclusions A lighter bicycle did not lead to a detectable difference in commuting time. Cyclists may find it more cost effective to reduce their own weight rather than to purchase a lighter bicycle. PMID:21148220

  19. Reducing employee travelling time through smart commuting

    NASA Astrophysics Data System (ADS)

    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.

  20. Non-commutative relativistic equation with a Coulomb potential

    SciTech Connect

    Zaim, Slimane; Khodja, Lamine; Delenda, Yazid

    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.

  1. Impact of commuter-rail services in Toronto region

    SciTech Connect

    Wells, S.S.; Hutchinson, B.G.

    1996-07-01

    Ridership of the commuter-rail system that was implemented in the Greater Toronto Area (GTA) in 1967 increased at an annual, average compound rate of 11.4% until 1989. Demand has leveled substantially during 1990--94 and has averaged only 2.1% per year, which probably reflects the suburbanization of employment. Urban economic theory is used to explain the way in which central-business-district (CBD) employees respond differently to suburban commuter-rail services and rapid transit services, mainly serving the inner intermediate suburbs. Travel data collected in 1986 and 1991 confirmed the effects suggested by the theory. Commuter-rail passengers are drawn from the larger suburban households, living principally in single-family houses, and commuter-rail passengers are more sensitive to access and egress distances than subway passengers. Policies that improve the quality of access and egress components of commuting trips from the suburbs stimulate passenger demand. Also, land-use policies that promote high-density, residential development at suburban commuter-rail stations are unlikely to contribute significantly to commuter-rail demand, and the lakeshore commuter-rail line that has been in service since 1967 has not had a significant impact on residential sorting and on the generation of additional demands.

  2. Understanding What Influences Successful Black Commuter Students' Engagement in College

    ERIC Educational Resources Information Center

    Yearwood, Trina Lynn; Jones, Elizabeth A.

    2012-01-01

    Black and commuter students are disadvantaged when it comes to higher education. Although black students are enrolling in college more than they did in previous years, fewer are earning degrees compared with their counterparts. Research asserts that students who live on campus are more engaged compared with students who commute. This is troubling…

  3. Unraveling the Image of Commutation Spark Generated in Universal Motors

    NASA Astrophysics Data System (ADS)

    Hanazawa, Tamio; Almazroui, Ali; Egashira, Torao

    A universal motor, which is mainly used in vacuum cleaners, generates commutation sparks at the moment when the brush and the commutator segment are separated from each other during rotation. This study investigates the mechanism of commutation spark generation by analyzing high-speed camera images and its electrical aspect. We invented a new external trigger method that used laser light as the trigger signal for the shuttering a high-speed camera. This method enabled us to photograph sparks on any desired commutator segments during high-speed rotation, and that made the analysis after photographing easier. This paper shows that commutation sparks in universal motors are generated on every other commutator segment and at the peak of pulses in the voltage between the brush and commutator segment. Other aspects are also clarified, such as the generation of the singular and plural number of sparks on one commutator segment at a time, the time from the moment of spark generation to extinction, and spark generation during a single rotation.

  4. Active Commuting Patterns at a Large, Midwestern College Campus

    ERIC Educational Resources Information Center

    Bopp, Melissa; Kaczynski, Andrew; Wittman, Pamela

    2011-01-01

    Objective: To understand patterns and influences on active commuting (AC) behavior. Participants: Students and faculty/staff at a university campus. Methods: In April-May 2008, respondents answered an online survey about mode of travel to campus and influences on commuting decisions. Hierarchical regression analyses predicted variance in walking…

  5. Parabosonic string and space-time non-commutativity

    SciTech Connect

    Seridi, M. A.; Belaloui, N.

    2012-06-27

    We investigate the para-quantum extension of the bosonic strings in a non-commutative space-time. We calculate the trilinear relations between the mass-center variables and the modes and we derive the Virasoro algebra where a new anomaly term due to the non-commutativity is obtained.

  6. Spontaneous Usage of Different Shortcuts Based on the Commutativity Principle

    PubMed Central

    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. PMID:24086413

  7. Effects of urban growth controls on intercity commuting.

    PubMed

    Ogura, Laudo M

    2010-01-01

    This paper presents an empirical study of the effects of urban growth controls on the intercity commuting of workers. Growth controls (land use regulations that attempt to restrict population growth and urban sprawl) have increased housing prices and diverted population growth to uncontrolled cities. It has been suggested that resulting changes in local labour supply might stimulate intercity commuting from uncontrolled to controlled cities. To test this hypothesis, a gravity model of commuting flows between places in California is estimated using alternative econometric methods (OLS, Heckman selection and count-data). The possibility of spatial dependence in commuting flows is also taken into consideration. Results suggest larger commuting flows to destination places that restrict residential growth. PMID:20722227

  8. Euler polynomials and identities for non-commutative operators

    NASA Astrophysics Data System (ADS)

    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.

  9. Effects of urban growth controls on intercity commuting.

    PubMed

    Ogura, Laudo M

    2010-01-01

    This paper presents an empirical study of the effects of urban growth controls on the intercity commuting of workers. Growth controls (land use regulations that attempt to restrict population growth and urban sprawl) have increased housing prices and diverted population growth to uncontrolled cities. It has been suggested that resulting changes in local labour supply might stimulate intercity commuting from uncontrolled to controlled cities. To test this hypothesis, a gravity model of commuting flows between places in California is estimated using alternative econometric methods (OLS, Heckman selection and count-data). The possibility of spatial dependence in commuting flows is also taken into consideration. Results suggest larger commuting flows to destination places that restrict residential growth.

  10. A non-commuting stabilizer formalism

    SciTech Connect

    Ni, Xiaotong; Van den Nest, Maarten; Buerschaper, Oliver

    2015-05-15

    We propose a non-commutative extension of the Pauli stabilizer formalism. The aim is to describe a class of many-body quantum states which is richer than the standard Pauli stabilizer states. In our framework, stabilizer operators are tensor products of single-qubit operators drawn from the group 〈αI, X, S〉, where α = e{sup iπ/4} and S = diag(1, i). We provide techniques to efficiently compute various properties related to bipartite entanglement, expectation values of local observables, preparation by means of quantum circuits, parent Hamiltonians, etc. We also highlight significant differences compared to the Pauli stabilizer formalism. In particular, we give examples of states in our formalism which cannot arise in the Pauli stabilizer formalism, such as topological models that support non-Abelian anyons.

  11. Accelerating commutation circuits in quantum computer networks

    NASA Astrophysics Data System (ADS)

    Jiang, Min; Huang, Xu; Chen, Xiaoping; Zhang, Zeng-ke

    2012-12-01

    In a high speed and packet-switched quantum computer network, a packet routing delay often leads to traffic jams, becoming a severe bottleneck for speeding up the transmission rate. Based on the delayed commutation circuit proposed in Phys. Rev. Lett. 97, 110502 (2006), we present an improved scheme for accelerating network transmission. For two more realistic scenarios, we utilize the characteristic of a quantum state to simultaneously implement a data switch and transmission that makes it possible to reduce the packet delay and route a qubit packet even before its address is determined. This circuit is further extended to the quantum network for the transmission of the unknown quantum information. The analysis demonstrates that quantum communication technology can considerably reduce the processing delay time and build faster and more efficient packet-switched networks.

  12. Electronically commutated dc motors for electric vehicles

    NASA Technical Reports Server (NTRS)

    Maslowski, E. A.

    1981-01-01

    A motor development program to explore the feasibility of electronically commutated dc motors (also known as brushless) for electric cars is described. Two different design concepts and a number of design variations based on these concepts are discussed. One design concept is based on a permanent magnet, medium speed, machine rated at 7000 to 9000 rpm, and powered via a transistor inverter power conditioner. The other concept is based on a permanent magnet, high speed, machine rated at 22,000 to 26,000 rpm, and powered via a thyristor inverter power conditioner. Test results are presented for a medium speed motor and a high speed motor each of which have been fabricated using samarium cobalt permanent magnet material.

  13. Electronically commutated dc motors for electric vehicles

    NASA Astrophysics Data System (ADS)

    Maslowski, E. A.

    A motor development program to explore the feasibility of electronically commutated dc motors (also known as brushless) for electric cars is described. Two different design concepts and a number of design variations based on these concepts are discussed. One design concept is based on a permanent magnet, medium speed, machine rated at 7000 to 9000 rpm, and powered via a transistor inverter power conditioner. The other concept is based on a permanent magnet, high speed, machine rated at 22,000 to 26,000 rpm, and powered via a thyristor inverter power conditioner. Test results are presented for a medium speed motor and a high speed motor each of which have been fabricated using samarium cobalt permanent magnet material.

  14. Electronically commutated motors for vehicle applications

    NASA Astrophysics Data System (ADS)

    Echolds, E. F.

    1980-02-01

    Two permanent magnet electronically commutated motors for electric vehicle traction are discussed. One, based on existing technology, produces 23 kW (peak) at 26,000 rpm, and 11 kW continuous at 18,000 rpm. The motor has a conventional design: a four-pole permanent magnet rotor and a three-phase stator similar to those used on ordinary induction motors. The other, advanced technology motor, is rated at 27 kW (peak) at 14,000 rpm, and 11 kW continuous at 10,500 rpm. The machine employs a permanent magnet rotor and a novel ironless stator design in an axial air gap, homopolar configuration. Comparison of the new motors with conventional brush type machines indicates potential for substantial cost savings.

  15. Commuting behavior of western U.S. residents

    SciTech Connect

    Caviglia, J. |

    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.

  16. Physical activity during leisure and commuting in Tianjin, China.

    PubMed Central

    Hu, Gang; Pekkarinen, Heikki; Hänninen, Osmo; Yu, Zhijie; Tian, Huiguang; Guo, Zeyu; Nissinen, Aulikki

    2002-01-01

    OBJECTIVE: To investigate physical activity during leisure time and commuting among persons aged 15-69 years in the urban population of Tianjin, China, and to assess its associations with demographic and health-related characteristics. METHODS: In 1996 a cross-sectional survey of 2002 males and 1974 females provided information on physical activity during leisure time and commuting and on demographics and health behaviours. FINDINGS: No leisure-time physical activity was engaged in by 67% of females and 61% of males. However, only 4% of females and 9% of males reported an absence of physical activity during commuting. The mean duration of leisure-time physical activity for the whole population was about 10 min per day. The average commuting time on foot or by bicycle was about 30 min. Leisure-time physical activity was more frequent among highly educated people, people with high incomes, white-collar workers, married people, non-smokers, or people commuting on foot or by bicycle than among other people. Persons with low incomes, male blue-collar workers and married people were more likely than others to engage in 30 min or more per day of physical activity on foot or by bicycle when commuting. CONCLUSION: People in Tianjin engaged in a high level of physical activity when commuting and a low level of leisure-time physical activity. PMID:12571720

  17. Generalized Uncertainty Relation in the Non-commutative Quantum Mechanics

    NASA Astrophysics Data System (ADS)

    Chung, Won Sang

    2016-06-01

    In this paper the non-commutative quantum mechanics (NCQM) with the generalized uncertainty relations {Δ } x1 {Δ } x2 ≥ {θ}/{2}, {Δ} p1 {Δ } p2 ≥ {bar{θ}}/{2}, {Δ } xi {Δ } pi ≥ {hbar _{eff}}/{2} is discussed. Four each uncertainty relation, wave functions saturating each uncertainty relation are explicitly constructed. The unitary operators relating the non-commutative position and momentum operators to the commutative position and momentum operators are also investigated. We also discuss the uncertainty relation related to the harmonic oscillator.

  18. Gauge transformation and symmetries of the commutative multicomponent BKP hierarchy

    NASA Astrophysics Data System (ADS)

    Li, Chuanzhong

    2016-01-01

    In this paper, we defined a new multi-component B type Kadomtsev-Petviashvili (BKP) hierarchy that takes values in a commutative subalgebra of {gl}(N,{{C}}). After this, we give the gauge transformation of this commutative multicomponent BKP (CMBKP) hierarchy. Meanwhile, we construct a new constrained CMBKP hierarchy that contains some new integrable systems, including coupled KdV equations under a certain reduction. After this, the quantum torus symmetry and quantum torus constraint on the tau function of the commutative multi-component BKP hierarchy will be constructed.

  19. 14 CFR 298.52 - Air taxi operations by commuter air carriers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A...

  20. 14 CFR 298.52 - Air taxi operations by commuter air carriers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A...

  1. 14 CFR 298.52 - Air taxi operations by commuter air carriers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A...

  2. 14 CFR 298.52 - Air taxi operations by commuter air carriers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A...

  3. 14 CFR 298.52 - Air taxi operations by commuter air carriers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Air taxi operations by commuter air... (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS EXEMPTIONS FOR AIR TAXI AND COMMUTER AIR CARRIER OPERATIONS Commuter Air Carrier Authorizations § 298.52 Air taxi operations by commuter air carriers. (a) A...

  4. 14 CFR 23.574 - Metallic damage tolerance and fatigue evaluation of commuter category airplanes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... evaluation of commuter category airplanes. 23.574 Section 23.574 Aeronautics and Space FEDERAL AVIATION... COMMUTER CATEGORY AIRPLANES Structure Fatigue Evaluation § 23.574 Metallic damage tolerance and fatigue evaluation of commuter category airplanes. For commuter category airplanes— (a) Metallic damage tolerance....

  5. 14 CFR 23.574 - Metallic damage tolerance and fatigue evaluation of commuter category airplanes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... evaluation of commuter category airplanes. 23.574 Section 23.574 Aeronautics and Space FEDERAL AVIATION... COMMUTER CATEGORY AIRPLANES Structure Fatigue Evaluation § 23.574 Metallic damage tolerance and fatigue evaluation of commuter category airplanes. For commuter category airplanes— (a) Metallic damage tolerance....

  6. Leptogenesis from a Non Commutative FRW Like Model

    SciTech Connect

    Mebarki, O.; Mebarki, N.; Aissaoui, H.

    2010-10-31

    A pure NCG leptonic asymmetry is obtained for particles propagating in a curved non commutative FRW universe. It is shown that because of the space-time deformation, an axial like symmetry is generated.

  7. On the renormalization of non-commutative field theories

    NASA Astrophysics Data System (ADS)

    Blaschke, Daniel N.; Garschall, Thomas; Gieres, François; Heindl, Franz; Schweda, Manfred; Wohlgenannt, Michael

    2013-01-01

    This paper addresses three topics concerning the quantization of non-commutative field theories (as defined in terms of the Moyal star product involving a constant tensor describing the non-commutativity of coordinates in Euclidean space). To start with, we discuss the Quantum Action Principle and provide evidence for its validity for non-commutative quantum field theories by showing that the equation of motion considered as insertion in the generating functional Z c [ j] of connected Green functions makes sense (at least at one-loop level). Second, we consider the generalization of the BPHZ renormalization scheme to non-commutative field theories and apply it to the case of a self-interacting real scalar field: Explicit computations are performed at one-loop order and the generalization to higher loops is commented upon. Finally, we discuss the renormalizability of various models for a self-interacting complex scalar field by using the approach of algebraic renormalization.

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

    SciTech Connect

    Calcagni, Gianluca; Kuroyanagi, Sachiko; Ohashi, Junko; Tsujikawa, Shinji E-mail: skuro@rs.tus.ac.jp E-mail: shinji@rs.kagu.tus.ac.jp

    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.

  9. Classical limits of quantum mechanics on a non-commutative configuration space

    SciTech Connect

    Benatti, Fabio; Gouba, Laure

    2013-06-15

    We consider a model of non-commutative quantum mechanics given by two harmonic oscillators over a non-commutative two dimensional configuration space. We study possible ways of removing the non-commutativity based on the classical limit context known as anti-Wick quantization. We show that removal of non-commutativity from the configuration space and from the canonical operators is not commuting operation.

  10. Non-commutativity, teleology and GRB time delay

    NASA Astrophysics Data System (ADS)

    Li, Miao; Pang, Yi; Wang, Yi

    2010-01-01

    We propose a model in which an energy-dependent time delay of a photon originates from space-time non-commutativity, the time delay is due to a non-commutative coupling between dilaton and photon. We predict that in our model, high energy photons with different momentum can either be delayed or superluminal, this may be related to a possible time delay reported by the Fermi LAT and Fermi GBM Collaborations.

  11. Advanced propfan analysis for the family of commuter airplanes

    NASA Technical Reports Server (NTRS)

    Swift, Gerald A.; Creighton, Tom; Haddad, Raphael; Hendrich, Louis; Hensley, Doug; Morgan, Louise; Russell, Mark

    1987-01-01

    Advanced propfans were selected to be used throughout the family of commuters. These propulsion systems offer a 25 to 28 percent fuel savings over comparably sized turbofans operating in the 1990s. A brief study of the propulsion systems available for the family of commuters is provided and the selection of the advanced turboprops justified. The propeller and engine designs and performance are discussed. The integration of these designs are examined. Also addressed is the noise considerations and constraints due to propfan installation.

  12. Non-commutativity and Local Indistinguishability of Quantum States

    PubMed Central

    Ma, Teng; Zhao, Ming-Jing; Wang, Yao-Kun; Fei, Shao-Ming

    2014-01-01

    We study the local indistinguishability problem of quantum states. By introducing an easily calculated quantity, non-commutativity, we present an criterion which is both necessary and sufficient for the local indistinguishability of a complete set of pure orthogonal product states. A constructive distinguishing procedure to obtain the concrete local measurements and classical communications is given. The non-commutativity of ensembles can be also used to characterize the quantumness for classical-quantum or quantum-classical correlated states. PMID:25208830

  13. What interventions increase commuter cycling? A systematic review

    PubMed Central

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

    2015-01-01

    Objective To identify interventions that will increase commuter cycling. Setting All settings where commuter cycling might take place. Participants Adults (aged 18+) in any country. Interventions Individual, group or environmental interventions including policies and infrastructure. Primary and secondary outcome measures 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. Results 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. Conclusions 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. PMID:26275902

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

    PubMed Central

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

    2015-01-01

    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. PMID:26322487

  15. Limits of Predictability in Commuting Flows in the Absence of Data for Calibration

    PubMed Central

    Yang, Yingxiang; Herrera, Carlos; Eagle, Nathan; González, Marta C.

    2014-01-01

    The estimation of commuting flows at different spatial scales is a fundamental problem for different areas of study. Many current methods rely on parameters requiring calibration from empirical trip volumes. Their values are often not generalizable to cases without calibration data. To solve this problem we develop a statistical expression to calculate commuting trips with a quantitative functional form to estimate the model parameter when empirical trip data is not available. We calculate commuting trip volumes at scales from within a city to an entire country, introducing a scaling parameter α to the recently proposed parameter free radiation model. The model requires only widely available population and facility density distributions. The parameter can be interpreted as the influence of the region scale and the degree of heterogeneity in the facility distribution. We explore in detail the scaling limitations of this problem, namely under which conditions the proposed model can be applied without trip data for calibration. On the other hand, when empirical trip data is available, we show that the proposed model's estimation accuracy is as good as other existing models. We validated the model in different regions in the U.S., then successfully applied it in three different countries. PMID:25012599

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

    PubMed Central

    Bopp, Melissa; Hastmann, Tanis J.; Norton, Alyssa N.

    2013-01-01

    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 (n = 437) 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). t-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 0.51 ± 1.93 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. PMID:24089620

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

    PubMed Central

    2010-01-01

    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. PMID:20609250

  18. Bias Assessment of General Chemistry Analytes using Commutable Samples.

    PubMed

    Koerbin, Gus; Tate, Jillian R; Ryan, Julie; Jones, Graham Rd; Sikaris, Ken A; Kanowski, David; Reed, Maxine; Gill, Janice; Koumantakis, George; Yen, Tina; St John, Andrew; Hickman, Peter E; Simpson, Aaron; Graham, Peter

    2014-11-01

    Harmonisation of reference intervals for routine general chemistry analytes has been a goal for many years. Analytical bias may prevent this harmonisation. To determine if analytical bias is present when comparing methods, the use of commutable samples, or samples that have the same properties as the clinical samples routinely analysed, should be used as reference samples to eliminate the possibility of matrix effect. The use of commutable samples has improved the identification of unacceptable analytical performance in the Netherlands and Spain. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has undertaken a pilot study using commutable samples in an attempt to determine not only country specific reference intervals but to make them comparable between countries. Australia and New Zealand, through the Australasian Association of Clinical Biochemists (AACB), have also undertaken an assessment of analytical bias using commutable samples and determined that of the 27 general chemistry analytes studied, 19 showed sufficiently small between method biases as to not prevent harmonisation of reference intervals. Application of evidence based approaches including the determination of analytical bias using commutable material is necessary when seeking to harmonise reference intervals.

  19. Development potential of Intermittent Combustion (I.C.) aircraft engines for commuter transport applications

    NASA Technical Reports Server (NTRS)

    Willis, E. A.

    1982-01-01

    An update on general aviation (g/a) and commuter aircraft propulsion research effort is reviewed. The following topics are discussed: on several advanced intermittent combustion engines emphasizing lightweight diesels and rotary stratified charge engines. The current state-of-the-art is evaluated for lightweight, aircraft suitable versions of each engine. This information is used to project the engine characteristics that can be expected on near-term and long-term time horizons. The key enabling technology requirements are identified for each engine on the long-term time horizon.

  20. A non-commutative framework for topological insulators

    NASA Astrophysics Data System (ADS)

    Bourne, C.; Carey, A. L.; Rennie, A.

    2016-04-01

    We study topological insulators, regarded as physical systems giving rise to topological invariants determined by symmetries both linear and anti-linear. Our perspective is that of non-commutative index theory of operator algebras. In particular, we formulate the index problems using Kasparov theory, both complex and real. We show that the periodic table of topological insulators and superconductors can be realized as a real or complex index pairing of a Kasparov module capturing internal symmetries of the Hamiltonian with a spectral triple encoding the geometry of the sample’s (possibly non-commutative) Brillouin zone.

  1. 77 FR 4326 - Announcement of Requirements and Registration for “Health Innovations in Commuting Challenge”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-27

    ...: Notice. SUMMARY: The purpose of this challenge is to highlight the role of health data during commutes and how it may play a critical role in improving the health of commuters. The ``Health Innovations...

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

    PubMed

    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.

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

    PubMed

    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. PMID:27660744

  4. 78 FR 75483 - Federal Travel Regulation (FTR); Relocation Allowances; Commuted Rate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-12

    ...] RIN 3090-AJ40 Federal Travel Regulation (FTR); Relocation Allowances; Commuted Rate AGENCY: Office of..., OGP, is providing a workable commuted rate to be used by agencies in determining a benchmark for... treated by Federal agencies as the commuted rate; that is, when a Federal employee moved his/her...

  5. 49 CFR 37.87 - Purchase or lease of used intercity and commuter rail cars.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... rail cars. 37.87 Section 37.87 Transportation Office of the Secretary of Transportation TRANSPORTATION....87 Purchase or lease of used intercity and commuter rail cars. (a) Except as provided elsewhere in this section, Amtrak or a commuter authority purchasing or leasing a used intercity or commuter...

  6. 49 CFR 37.87 - Purchase or lease of used intercity and commuter rail cars.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... rail cars. 37.87 Section 37.87 Transportation Office of the Secretary of Transportation TRANSPORTATION....87 Purchase or lease of used intercity and commuter rail cars. (a) Except as provided elsewhere in this section, Amtrak or a commuter authority purchasing or leasing a used intercity or commuter...

  7. Research Refutes a Myth: Commuter Students Do Want to Be Involved.

    ERIC Educational Resources Information Center

    Likins, Jeanne M.

    1991-01-01

    Examined commuter college students' (n=326) involvement in the university community. Results refute myth that commuter college students do not want to be involved or feel a part of the university community. Claims debunking myths about commuter students is a prerequisite to providing effective services and programs for students today. (ABL)

  8. On the Need for Separate Commuter Programs: San Diego State Looks at Its Students.

    ERIC Educational Resources Information Center

    McCully, Barbie

    1980-01-01

    A self-assessment of commuter student programs and services at San Diego State University (SDSU) indicated that the university was doing well in meeting the needs of this population. For many years, most of the students at SDSU have been commuter students. Services and programs that were developed were created with the commuter student in mind.…

  9. 49 CFR 37.85 - Purchase or lease of new intercity and commuter rail cars.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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...

  10. 49 CFR 37.85 - Purchase or lease of new intercity and commuter rail cars.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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...

  11. How To Give 'Em What They Want: Assessment Basics for Commuters.

    ERIC Educational Resources Information Center

    Rue, Penny

    1981-01-01

    Commuter students are often left out of college programs because their needs and schedules differ substantially from the traditional student for whom the programs are planned. Once the basic educational needs of the commuter student are being met, planners can focus on developing programs geared to other needs of the commuter such as personal…

  12. 49 CFR 37.85 - Purchase or lease of new intercity and commuter rail cars.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 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...

  13. 20 CFR 704.102 - Commutation of payments to aliens and nonresidents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false Commutation of payments to aliens and... FOR 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...

  14. 20 CFR 704.102 - Commutation of payments to aliens and nonresidents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false Commutation of payments to aliens and... FOR 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...

  15. 20 CFR 704.102 - Commutation of payments to aliens and nonresidents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Commutation of payments to aliens and... FOR 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...

  16. 20 CFR 704.102 - Commutation of payments to aliens and nonresidents.

    Code of Federal Regulations, 2010 CFR

    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...

  17. 20 CFR 704.102 - Commutation of payments to aliens and nonresidents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false Commutation of payments to aliens and... FOR 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...

  18. A perspective on non-commutative quantum gravity

    NASA Astrophysics Data System (ADS)

    Martins, Rachel A. D.

    2015-06-01

    In this paper, we present some of the concepts underlying a program of non-commutative quantum gravity and recall some of the results. This program includes a novel approach to spectral triple categorification and also a precise connection between Fell bundles and Connes' non-commutative geometry. Motivated by topics in quantization of the non-commutative standard model and introduction of algebraic techniques and concepts into quantum gravity (following for example Crane, Baez and Barrett), we define spectral C*-categories, which are deformed spectral triples in a sense made precise. This definition gives to representations of a C*-category on a small category of Hilbert spaces and bounded linear maps, the interpretation of a topological quantum field theory. The construction passes two mandatory tests: (i) there is a classical limit theorem reproducing a Riemannian spin manifold manifesting Connes' and Schücker's non-commutative counterpart of Einstein's equivalence principle, and (ii) there is consistency with the experimental fermion mass matrix. We also present an algebra invariant taking the form of a partition function arising from a C*-bundle dynamical system in connection with C*-subalgebra theory.

  19. Some Transportation Alternatives for Commuter Colleges and Universities.

    ERIC Educational Resources Information Center

    Hardwick, Mark W.; Kazlo, Martha P.

    This document is written in an effort to urge commuter colleges and universities to use their technical expertise in solving the automobile problem, which adds to the congestion and pollution in college communities. It has become a necessity that colleges and universities begin to explore ways to offer a variety of less expensive transportation…

  20. Active commuting to elementary school and adiposity: An observational study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Active commuting to school (ACS; walking or cycling to school) appears promising for decreasing children's obesity risk, although long-term studies are sparse. The aim was to examine whether kindergarten ACS was associated with fifth grade adiposity. This study was a secondary analysis of the Early ...

  1. 75 FR 13680 - Commutation of Sentence: Technical Change

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-23

    ... Bureau of Prisons 28 CFR Part 571 RIN 1120-AB54 Commutation of Sentence: Technical Change AGENCY: Bureau of Prisons, Justice. ACTION: Interim rule. SUMMARY: This document makes a minor technical change to... Sentence: Technical Change This document makes a minor technical change to the Bureau regulations...

  2. Commute alternatives systems handbook. Report for July 1993-June 1995

    SciTech Connect

    Winters, P.L.; Rudge, D.E.

    1995-08-01

    The Commute Alternative Handbook (CASH) provides a general introduction to Transportation Demand Management (TDM) that includes an overview of the national conditions which have led to increased TDM activities. This manual also describes various TDM strategies, implementation mechanisms and performance measurements.

  3. Analyses of School Commuting Data for Exposure Modeling Purposes

    EPA Science Inventory

    Human exposure models often make the simplifying assumption that school children attend school in the same Census tract where they live. This paper analyzes that assumption and provides information on the temporal and spatial distributions associated with school commuting. The d...

  4. FACTORS EFFECTING EXPOSURES TO VOCS DURING COMMUTING IN CALIFORNIA

    EPA Science Inventory

    On the average, Californian's spend between one and three hours each day commuting. The contribution from in-vehicle exposures to air toxics may be a significant component of total air exposure. Although pollutant concentration data are important for exposure assessments, onl...

  5. The Business Case for Commuter Benefits at Colleges and Universities

    ERIC Educational Resources Information Center

    Klavon, Patty

    2005-01-01

    Transportation and parking-related issues are common challenges for many colleges and universities today. Most institutions have far fewer parking spaces than they do commuters, and constructing and maintaining new parking facilities can cost hundreds of thousands of dollars. In this article, an Environmental Protection Agency representative…

  6. Regenerative Snubber For GTO-Commutated SCR Inverter

    NASA Technical Reports Server (NTRS)

    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.

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

    PubMed Central

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

    2016-01-01

    Objective 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. Method 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. Results 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. Conclusions 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. PMID:26740344

  8. Epidemic process over the commute network in a metropolitan area.

    PubMed

    Yashima, Kenta; Sasaki, Akira

    2014-01-01

    An understanding of epidemiological dynamics is important for prevention and control of epidemic outbreaks. However, previous studies tend to focus only on specific areas, indicating that application to another area or intervention strategy requires a similar time-consuming simulation. Here, we study the epidemic dynamics of the disease-spread over a commute network, using the Tokyo metropolitan area as an example, in an attempt to elucidate the general properties of epidemic spread over a commute network that could be used for a prediction in any metropolitan area. The model is formulated on the basis of a metapopulation network in which local populations are interconnected by actual commuter flows in the Tokyo metropolitan area and the spread of infection is simulated by an individual-based model. We find that the probability of a global epidemic as well as the final epidemic sizes in both global and local populations, the timing of the epidemic peak, and the time at which the epidemic reaches a local population are mainly determined by the joint distribution of the local population sizes connected by the commuter flows, but are insensitive to geographical or topological structure of the network. Moreover, there is a strong relation between the population size and the time that the epidemic reaches this local population and we are able to determine the reason for this relation as well as its dependence on the commute network structure and epidemic parameters. This study shows that the model based on the connection between the population size classes is sufficient to predict both global and local epidemic dynamics in metropolitan area. Moreover, the clear relation of the time taken by the epidemic to reach each local population can be used as a novel measure for intervention; this enables efficient intervention strategies in each local population prior to the actual arrival.

  9. Using a PFET To Commutate an SCR

    NASA Technical Reports Server (NTRS)

    Edwards, D. B.; Ripple, W. E.

    1984-01-01

    Accidental turn-on prevented. PFET diverts load current around SCR to prevent false SCR triggering from current and voltage switching transients. New circuit used in all types of single phase and polyphase inverters and in buck-boost-, and flyback regulators.

  10. Association Between User-Generated Commuting Data and Population-Representative Active Commuting Surveillance Data - Four Cities, 2014-2015.

    PubMed

    Whitfield, Geoffrey P; Ussery, Emily N; Riordan, Brian; Wendel, Arthur M

    2016-01-01

    Creating environments that support all types of physical activity, including active transportation, is a public health priority (1). Public health surveillance that identifies the locations where community members walk and bicycle (i.e., engage in active transportation) can inform such efforts. Traditional population-representative active transportation surveillance incurs a considerable time lag between data collection and dissemination, and often lacks geographic specificity (2). Conversely, user-generated active transportation data from Global Positioning System (GPS)-based activity tracking devices and mobile applications can provide near real-time information, but might be subject to self-selection bias among users. CDC analyzed the association between GPS-based commuting data from a company that allows tracking of activity with a mobile application (Strava, Inc., San Francisco, California) and population-representative commuting data from the U.S. Census Bureau's American Community Survey (ACS) (3) for four U.S. cities. The level of analysis was the Census block group. The number of GPS-tracked commuters in Strava was associated with the number of ACS active commuters (Spearman's rho = 0.60), suggesting block groups were ranked similarly based on these distinct but related measurements. The correlation was higher in high population density areas. User-generated active transportation data might complement traditional surveillance systems by providing near real-time, location-specific information on where active transportation occurs. PMID:27632357

  11. Association Between User-Generated Commuting Data and Population-Representative Active Commuting Surveillance Data - Four Cities, 2014-2015.

    PubMed

    Whitfield, Geoffrey P; Ussery, Emily N; Riordan, Brian; Wendel, Arthur M

    2016-09-16

    Creating environments that support all types of physical activity, including active transportation, is a public health priority (1). Public health surveillance that identifies the locations where community members walk and bicycle (i.e., engage in active transportation) can inform such efforts. Traditional population-representative active transportation surveillance incurs a considerable time lag between data collection and dissemination, and often lacks geographic specificity (2). Conversely, user-generated active transportation data from Global Positioning System (GPS)-based activity tracking devices and mobile applications can provide near real-time information, but might be subject to self-selection bias among users. CDC analyzed the association between GPS-based commuting data from a company that allows tracking of activity with a mobile application (Strava, Inc., San Francisco, California) and population-representative commuting data from the U.S. Census Bureau's American Community Survey (ACS) (3) for four U.S. cities. The level of analysis was the Census block group. The number of GPS-tracked commuters in Strava was associated with the number of ACS active commuters (Spearman's rho = 0.60), suggesting block groups were ranked similarly based on these distinct but related measurements. The correlation was higher in high population density areas. User-generated active transportation data might complement traditional surveillance systems by providing near real-time, location-specific information on where active transportation occurs.

  12. Mass Commuting and Influenza Vaccination Prevalence in New York City: Protection in a Mixing Environment

    PubMed Central

    Levine, Burton; Wilcosky, Tim; Wagener, Diane; Cooley, Phillip

    2010-01-01

    Objective Assess influenza vaccination among commuters using mass transit in New York City (NYC). Methods We used the 2006 NYC Community Health Survey (CHS) to analyze the prevalence of influenza immunization by commuting behaviors and to understand what socioeconomic and geographic factors may explain any differences found. Results Vaccination prevalence is significantly lower for New Yorkers who commute on public transportation compared to other New Yorkers. This difference is largely attenuated after adjusting for socio-demographic characteristics and neighborhood of residence. Conclusions The analysis identified a low prevalence of immunization among commuters, and given the transmissibility in that setting, targeting commuters for vaccination campaigns may impede influenza spread. PMID:21218159

  13. Relationships Between Commuting and Social Capital Among Men and Women in Southern Sweden

    PubMed Central

    Håkansson, Carita; Jakobsson, Kristina

    2015-01-01

    The societal need for a mobile workforce increases time spent commuting and thus also the total workday. How this affects individual well-being and social life is, however, surprisingly little known. We investigated the relation between commuting time and mode, and social participation and general trust in other people as measures of social capital, using data from public health surveys conducted in 2004 and 2008 in Scania, Sweden: in all, 21,088 persons ages 18 to 65 and working at least 30 hr per week. Commuting by car was significantly associated with a higher prevalence of low social participation and low general trust compared with active commuting, and the association increased with the duration of commuting time. In contrast, public commuting was not significantly associated with decreased social capital measures except among long-duration commuters, who reported lower social participation. The overall pattern was similar for men and for women. PMID:26273107

  14. Application of variable-sweep wings to commuter aircraft

    NASA Technical Reports Server (NTRS)

    Robins, A. W.; Beissner, F. L., Jr.; Lovell, W. A.; Price, J. E.; Turriiziani, R. V.; Washburn, F. F.

    1983-01-01

    The effects of using variable-sweep wings on the riding quality and mission-performance characteristics of commuter-type aircraft were studied. A fixed-wing baseline vehicle and a variable-sweep version of the baseline were designed and evaluated. Both vehicles were twin-turboprop, pressurized-cabin, 30-passenger commuter aircraft with identical mission requirements. Mission performance was calculated with and without various ride-quality constraints for several combinations of cruise altitude and stage lengths. The variable-sweep aircraft had a gross weight of almost four percent greater than the fixed-wing baseline in order to meet the design-mission requirements. In smooth air, the variable sweep configuration flying with low sweep had a two to three percent fuel-use penalty. However, the imposition of quality constraints in rough air can result in advantages in both fuel economy and flight time for the variable-sweep vehicle flying with high sweep.

  15. Commuting flows and conservation laws for noncommutative Lax hierarchies

    SciTech Connect

    Hamanaka, Masashi

    2005-05-01

    We discuss commuting flows and conservation laws for Lax hierarchies on noncommutative spaces in the framework of the Sato theory. On commutative spaces, the Sato theory has revealed essential aspects of the integrability for wide class of soliton equations which are derived from the Lax hierarchies in terms of pseudodifferential operators. Noncommutative extension of the Sato theory has been already studied by the author and Toda, and the existence of various noncommutative Lax hierarchies are guaranteed. In this paper, we present conservation laws for the noncommutative Lax hierarchies with both space-space and space-time noncommutativities and prove the existence of infinite number of conserved densities. We also give the explicit representations of them in terms of Lax operators. Our results include noncommutative versions of KP, KdV, Boussinesq, coupled KdV, Sawada-Kotera, modified KdV equation and so on.

  16. Determination of the flight equipment maintenance costs of commuter airlines

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Labor and materials costs associated with maintaining and operating 12 commuter airlines carrying an average of from 42 to 1,100 passengers daily in a variety of aircraft types were studied to determine the total direct maintenance cost per flight hour for the airframe, engine, and avionics and other instruments. The distribution of maintenance costs are analyzed for two carriers, one using turboprop aircraft and the other using piston engine aircraft.

  17. Rapid commutation duplexer with phase-related outputs

    NASA Astrophysics Data System (ADS)

    Roveda, R.; Cattarin, G.; Digregorio, C.; Parrucci, U.

    Design criteria and the realization of an X-band waveguide rapid commutation duplexer, in production, are presented. By means of a digital TTL command it is capable of operating in three different conditions: all the power is conveyed to a single output; the poweer is equally divided between two in-phase outputs; and it is equally divided between two counter-phase outputs. In a monopulse radar this permits the electronic scanning of the antenna beam.

  18. Semiclassical and quantum motions on the non-commutative plane

    NASA Astrophysics Data System (ADS)

    Baldiotti, M. C.; Gazeau, J. P.; Gitman, D. M.

    2009-10-01

    We study the canonical and the coherent state quantizations of a particle moving in a magnetic field on the non-commutative plane. Using a θ-modified action, we perform the canonical quantization and analyze the gauge dependence of the theory. We compare coherent states quantizations obtained through Malkin-Man'ko states and circular squeezed states. The relation between these states and the “classical” trajectories is investigated, and we present numerical explorations of some semiclassical quantities.

  19. Commutability of Cytomegalovirus WHO International Standard in Different Matrices

    PubMed Central

    Jones, Sara; Webb, Erika M.; Barry, Catherine P.; Choi, Won S.; Abravaya, Klara B.; Schneider, George J.

    2016-01-01

    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. PMID:27030491

  20. [Relationships between settlement morphology transition and residents commuting energy consumption].

    PubMed

    Zhou, Jian; Xiao, Rong-Bo; Sun, Xiang

    2013-07-01

    Settlement morphology transition is triggered by rapid urbanization and urban expansion, but its relationships with residents commuting energy consumption remains ambiguous. It is of significance to understand the controlling mechanisms of sustainable public management policies on the energy consumption and greenhouse gases emission during the process of urban settlement morphology transition. Taking the Xiamen City of East China as a case, and by using the integrated land use and transportation modeling system TRANUS, a scenario analysis was made to study the effects of urban settlement morphology transition on the urban spatial distribution of population, jobs, and land use, and on the residents commuting energy consumption and greenhouse gasses emission under different scenarios. The results showed that under the Business As Usual (BAU) scenario, the energy consumption of the residents at the morning peak travel time was 54.35 tce, and the CO2 emission was 119.12 t. As compared with those under BAU scenario, both the energy consumption and the CO2 emission under the Transition of Settlement Morphology (TSM) scenario increased by 12%, and, with the implementation of the appropriate policies such as land use, transportation, and economy, the energy consumption and CO2 emission under the Transition of Settlement Morphology with Policies (TSMP) scenario reduced by 7%, indicating that urban public management policies could effectively control the growth of residents commuting energy consumption and greenhouse gases emission during the period of urban settlement morphology transition.

  1. Modelling the relation between income and commuting distance.

    PubMed

    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. PMID:27278365

  2. Magnetic-free non-reciprocity based on staggered commutation

    PubMed Central

    Reiskarimian, Negar; Krishnaswamy, Harish

    2016-01-01

    Lorentz reciprocity is a fundamental characteristic of the vast majority of electronic and photonic structures. However, non-reciprocal components such as isolators, circulators and gyrators enable new applications ranging from radio frequencies to optical frequencies, including full-duplex wireless communication and on-chip all-optical information processing. Such components today dominantly rely on the phenomenon of Faraday rotation in magneto-optic materials. However, they are typically bulky, expensive and not suitable for insertion in a conventional integrated circuit. Here we demonstrate magnetic-free linear passive non-reciprocity based on the concept of staggered commutation. Commutation is a form of parametric modulation with very high modulation ratio. We observe that staggered commutation enables time-reversal symmetry breaking within very small dimensions (λ/1,250 × λ/1,250 in our device), resulting in a miniature radio-frequency circulator that exhibits reduced implementation complexity, very low loss, strong non-reciprocity, significantly enhanced linearity and real-time reconfigurability, and is integrated in a conventional complementary metal–oxide–semiconductor integrated circuit for the first time. PMID:27079524

  3. A study of commuter airplane design optimization

    NASA Technical Reports Server (NTRS)

    Keppel, B. V.; Eysink, H.; Hammer, J.; Hawley, K.; Meredith, P.; Roskam, J.

    1978-01-01

    The usability of the general aviation synthesis program (GASP) was enhanced by the development of separate computer subroutines which can be added as a package to this assembly of computerized design methods or used as a separate subroutine program to compute the dynamic longitudinal, lateral-directional stability characteristics for a given airplane. Currently available analysis methods were evaluated to ascertain those most appropriate for the design functions which the GASP computerized design program performs. Methods for providing proper constraint and/or analysis functions for GASP were developed as well as the appropriate subroutines.

  4. Hybrid generalized Bosbach and Rie c̆ an states on non-commutative residuated lattices

    NASA Astrophysics Data System (ADS)

    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".

  5. Trade-offs between commuting time and health-related activities.

    PubMed

    Christian, Thomas J

    2012-10-01

    To further understand documented associations between obesity and urban sprawl, this research describes individuals' trade-offs between health-related activities and commuting time. A cross-section of 24,861 working-age individuals employed full-time and residing in urban counties is constructed from the American Time Use Survey (2003-2010). Data are analyzed using seemingly unrelated regressions to quantify health-related activity decreases in response to additional time spent commuting. Outcomes are total daily minutes spent in physical activity at a moderate or greater intensity, preparing food, eating meals with family, and sleeping. Commuting time is measured as all travel time between home and work and vice versa. The mean commuting time is 62 min daily, the median is 55 min, and 10.1% of workers commute 120 min or more. Spending an additional 60 min daily commuting above average is associated with a 6% decrease in aggregate health-related activities and spending an additional 120 min is associated with a 12% decrease. The greatest percentage of commuting time comes from sleeping time reductions (28-35%). Additionally, larger proportions of commuting time are taken from physical activity and food preparation relative to the mean commuting length: of 60 min spent commuting, 16.1% is taken from physical activity and 4.1% is taken from food preparation; of 120 min commuting, 20.3% is taken from physical activity and 5.6% is taken from food preparation. The results indicate that longer commutes are associated with behavioral patterns which over time may contribute to obesity and other poor health outcomes. These findings will assist both urban planners and researchers wishing to understand time constraints' impacts on health. PMID:22689293

  6. Potential health impact of switching from car to public transportation when commuting to work.

    PubMed

    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.

  7. 14 CFR 135.398 - Commuter category airplanes performance operating limitations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... all commuter category airplanes notwithstanding their stated applicability to turbine-engine-powered... used, the elevation of the airport, the effective runway gradient, and ambient temperature, and...

  8. 14 CFR 135.398 - Commuter category airplanes performance operating limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... all commuter category airplanes notwithstanding their stated applicability to turbine-engine-powered... used, the elevation of the airport, the effective runway gradient, and ambient temperature, and...

  9. Commuting alternatives in the United States: Recent trends and a look to the future. Final report, July 1993-December 1994

    SciTech Connect

    Ball, W.L.

    1994-12-01

    Commuting in the U.S. has evolved substantially over the past several decades, from the more traditional commute with a majority of destinations in the central business district to new travel patterns where commuting from suburb to suburb has grown to be the dominant commuting pattern. The report was prepared to assist in developing a through understanding of recent trends in commuting alternatives in the U.S. Using data from the Census, American Housing Survey (AHS), and the Nationwide Personal Transportation Study (NPTS), general trends in commuting are presented, including those related to mode choice, vehicle occupancy, departure time, travel time, and travel distance.

  10. Intimate Partner Violence Risk among Undergraduate Women from an Urban Commuter College: the Role of Navigating Off- and On-Campus Social Environments.

    PubMed

    Tsui, Emma K; Santamaria, E Karina

    2015-06-01

    The current attention that is being paid to college sexual assault in policy circles and popular media overlooks a critical issue: the possible role played by the urban social environment in intimate partner violence (IPV) risk for the large number of urban commuter college students throughout the USA and beyond. This article helps to illuminate this dynamic using qualitative research collected at an urban commuter campus in New York City. Specifically, we conducted focus groups and in-depth interviews with 18 female undergraduate students, exploring the nature and consequences of IPV in students' lives, perceived prevalence of IPV, and resources for addressing IPV. Our results indicate that college attendance may both elevate and protect against IPV risk for students moving between urban off- and on-campus social environments. Based on this, we present a preliminary model of IPV risk for undergraduate women attending urban commuter colleges. In particular, we find that enrolling in college can sometimes elevate risk of IPV when a partner seeks to limit and control their student partner's experience of college and/or is threatened by what may be achieved by the partner through attending college. These findings suggest a role for urban commuter colleges in helping to mitigate IPV risk through policy formulation and comprehensive ongoing screening and prevention activities.

  11. Analysis of School Commuting Data for Exposure Modeling Purposes

    SciTech Connect

    Xue, Jianping; McCurdy, Thomas; Burke, Janet; Bhaduri, Budhendra L; Liu, Cheng; Nutaro, James J; Patterson, Lauren A

    2010-01-01

    Human exposure models often make the simplifying assumption that school children attend school in the same census tract where they live. This paper analyzes that assumption and provides information on the temporal and spatial distributions associated with school commuting. The data were obtained using Oak Ridge National Laboratory s LandScan USA population distribution model (Bhaduri et al., 2007) applied to Philadelphia PA. It is a high-resolution model used to allocate individual school-aged children to both a home and school location, and to devise a minimum-time home-to school commuting path (called a trace) between the two locations. LandScan relies heavily on Geographic Information System (GIS) data. Our GIS analyses found that in Philadelphia: (1) about 32% of the students walk across 2 or more census tracts and 40% of them walk across 4 or more census blocks; (2) 60% drive across 4 or more census tracts going to school and 50% drive across 10 or more census blocks; (3) five-minute commuting time intervals result in misclassification as high as 90% for census blocks, 70% for block groups, and 50% for census tracts; (4) a one-minute time interval is needed to reasonably resolve time spent in the various census unit designations; (5) approximately 50% of both schoolchildren s homes and schools are located within 160 m of highly-traveled roads, and 64% of the schools are located within 200 m. These findings are very important when modeling school children s exposures, especially when ascertaining the impacts of near-roadway concentrations on their total daily body burden. Since many school children also travel along these streets and roadways to get to school, a majority of children in Philadelphia are in mobile-source dominated locations most of the day. We hypothesize that exposures of school children in Philadelphia to benzene and particulate matter will be much higher than if home and school locations and commuting paths at a 1-minute time resolution are

  12. On the essential spectrum of certain non-commutative oscillators

    SciTech Connect

    Parmeggiani, Alberto Venni, Alberto

    2013-12-15

    We show here that the spectrum of the family of non-commutative harmonic oscillators Q{sub (α,β)}{sup w}(x,D) for α,β∈R{sub +} in the range αβ = 1 is [0, +∞) and is entirely essential spectrum. The previous existing results concern the case αβ > 1 (case in which Q{sub (α,β)}{sup w}(x,D) is globally elliptic with a discrete spectrum whose qualitative properties are being extensively studied), and ours therefore extend the picture to the range of parameters αβ ⩾ 1.

  13. Promoting health and safety for traveling and commuting employees.

    PubMed

    Pochat-Debroux, Sophia

    2008-09-01

    In a society that relies on a growing market economy and free enterprise, Americans spend inordinate time commuting and traveling for work. Aircraft and private vehicles are the two primary modes of work-related travel, with each having its own inherit risks and hazards. Although much has been written about international travel health, little has been published about protecting the health and safety of workers during domestic business travel. The intent of this article is to highlight the statistics associated with domestic business travel and present sound rationale for an inclusive and comprehensive domestic travel health and safety program for employees. PMID:18792614

  14. Using a micromachined magnetostatic relay in commutating a DC motor

    NASA Technical Reports Server (NTRS)

    Tai, Yu-Chong (Inventor); Wright, John A. (Inventor); Lilienthal, Gerald (Inventor)

    2004-01-01

    A DC motor is commutated by rotating a magnetic rotor to induce a magnetic field in at least one magnetostatic relay in the motor. Each relay is activated in response to the magnetic field to deliver power to at least one corresponding winding connected to the relay. In some cases, each relay delivers power first through a corresponding primary winding and then through a corresponding secondary winding to a common node. Specific examples include a four-pole, three-phase motor in which each relay is activated four times during one rotation of the magnetic rotor.

  15. Rotating turkeys and self-commutating artificial muscle motors

    NASA Astrophysics Data System (ADS)

    O'Brien, Benjamin M.; McKay, Thomas G.; Gisby, Todd A.; Anderson, Iain A.

    2012-02-01

    Electrostatic motors—first used by Benjamin Franklin to rotisserie a turkey—are making a comeback in the form of high energy density dielectric elastomer artificial muscles. We present a self-commutated artificial muscle motor that uses dielectric elastomer switches in the place of bulky external electronics. The motor simply requires a DC input voltage to rotate a shaft (0.73 Nm/kg, 0.24 Hz) and is a step away from hard metallic electromagnetic motors towards a soft, light, and printable future.

  16. Remote Sensing with Commutable Monolithic Laser and Detector

    PubMed Central

    2016-01-01

    The ubiquitous trend toward miniaturized sensing systems demands novel concepts for compact and versatile spectroscopic tools. Conventional optical sensing setups include a light source, an analyte interaction region, and a separate external detector. We present a compact sensor providing room-temperature operation of monolithic surface-active lasers and detectors integrated on the same chip. The differentiation between emitter and detector is eliminated, which enables mutual commutation. Proof-of-principle gas measurements with a limit of detection below 400 ppm are demonstrated. This concept enables a crucial miniaturization of sensing devices. PMID:27785455

  17. User satisfaction with commuter walk-in centres.

    PubMed

    Coster, Joanne; O'Cathain, Alicia; Nicholl, Jon; Salisbury, Chris

    2009-12-01

    Pilot commuter walk-in centres have been located close to national rail stations in major English cities, provided by private healthcare companies for the NHS, and offering access to doctors and nurses. This study used a survey to evaluate user satisfaction levels with this new service. Thirty-three per cent (1828/5574) of users completed a questionnaire. Centres demonstrated high levels of user satisfaction (69% 'very satisfied', 95% confidence interval = 58% to 79%) overall, but satisfaction was lower for some aspects of care such as waiting times. PMID:20875252

  18. Commuting mode and pulmonary function in Shanghai, China.

    PubMed

    Gaffney, Adam W; Hang, Jing-Qing; Lee, Mi-Sun; Su, Li; Zhang, Feng-Ying; Christiani, David C

    2016-03-01

    Exposure to air pollution can be particularly high during commuting and may depend on the mode of transportation. We investigated the impact of commuting mode on pulmonary function in Shanghai, China.The Shanghai Putuo Study is a cross-sectional, population-based study. Our primary outcomes were forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) % predicted, and the secondary outcome was spirometric airflow obstruction. We tested the association between mode of transportation and these outcomes after adjusting for confounders.The study population consisted of 20 102 subjects. After adjusting for confounders, the change (95% CI) in FEV1 was -2.15% pred (-2.88- -1.42% pred) among pedestrians, -1.32% pred (-2.05- -0.59% pred) among those taking buses without air conditioning, -1.33% pred (-2.05- -0.61% pred) among those taking buses with air conditioning and -2.83% pred (-5.56- -0.10% pred) among those using underground railways, as compared to cyclists (the reference group). The effects of mode on FVC % predicted were in the same direction. Private car use had a significant protective effect on FVC % predicted and the risk of airflow obstruction (defined by Global Initiative for Chronic Obstructive Lung Disease but not by lower limit of normal criteria).Mode of transportation is associated with differences in lung function, which may reflect pollution levels in different transportation microenvironments. PMID:26541519

  19. Differences in active commuting among younger and older adults.

    PubMed

    Bopp, Melissa; Der Ananian, Cheryl; Campbell, Matthew E

    2014-04-01

    The demonstrated health benefits of active commuting (AC) and low participation rates among older adults indicate a need to examine the socioecological correlates of AC by age category. An online survey of employed U.S. adults examined AC participation and individual, employment-related, community, and environmental variables. Participants were dichotomized by age (younger: 18-49 yr; n = 638, 64% and older: ≥ 50 yr; n = 359, 36%). Logistic-regression analyses examined differences in AC correlates by age. Older adults were less likely to be active commuters (13.4%) than younger adults (27.9%; p < .001) For older adults, analyses yielded a Nagelkerke R2 = .76, with perceived behavioral control, behavioral beliefs, household cars, and walking distance as predictors. Analyses for younger adults resulted in a Nagelkerke R2 = .79, with perceived behavioral control, coworker normative beliefs, parking problems at work, greater employer and community support for AC, and bad weather as predictors. Findings suggest age should be considered when examining and targeting AC behaviors.

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

    PubMed Central

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

    2015-01-01

    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. PMID:25898405

  1. Differences in active commuting among younger and older adults.

    PubMed

    Bopp, Melissa; Der Ananian, Cheryl; Campbell, Matthew E

    2014-04-01

    The demonstrated health benefits of active commuting (AC) and low participation rates among older adults indicate a need to examine the socioecological correlates of AC by age category. An online survey of employed U.S. adults examined AC participation and individual, employment-related, community, and environmental variables. Participants were dichotomized by age (younger: 18-49 yr; n = 638, 64% and older: ≥ 50 yr; n = 359, 36%). Logistic-regression analyses examined differences in AC correlates by age. Older adults were less likely to be active commuters (13.4%) than younger adults (27.9%; p < .001) For older adults, analyses yielded a Nagelkerke R2 = .76, with perceived behavioral control, behavioral beliefs, household cars, and walking distance as predictors. Analyses for younger adults resulted in a Nagelkerke R2 = .79, with perceived behavioral control, coworker normative beliefs, parking problems at work, greater employer and community support for AC, and bad weather as predictors. Findings suggest age should be considered when examining and targeting AC behaviors. PMID:23689245

  2. Commuter exposure to aerosol pollution on public transport in Singapore

    NASA Astrophysics Data System (ADS)

    Tan, S.; Velasco, E.; Roth, M.; Norford, L.

    2013-12-01

    Personal exposure to aerosol pollutants in the transport microenvironment of Singapore has not been well documented. Studies from many cities suggest that brief periods of exposure to high concentrations of airborne pollutants may have significant health impacts. Thus, a large proportion of aerosol exposure may be experienced during daily commuting trips due to the proximity to traffic. A better understanding of the variability across transport modes is therefore needed to design transport policies that minimize commuters' exposure. In light of this, personal exposure measurements of PM10 and PM2.5, particle number (PN), black carbon (BC), carbon monoxide (CO), particle-bound polycyclic aromatic hydrocarbons (pPAH), and active surface area (SA) were conducted on a selected route in downtown Singapore. Portable and real-time monitoring instruments were carried onto three different modes of public transport (bus, taxi, subway) and by foot. Simultaneous measurements were taken at a nearby park to capture the background concentrations. Large variability was observed amongst the various transport modes investigated. For example, the particle number concentration was on average 1.5, 1.6, 0.8, and 2.2 times higher inside buses, taxis, subway and by foot, respectively, than at the background site. Based on the results, it is possible to come up with a ranking of the 'cleanest' transport mode for Singapore.

  3. Numerical simulation of nonlinear dynamical systems driven by commutative noise

    SciTech Connect

    Carbonell, F. Biscay, R.J.; Jimenez, J.C.; Cruz, H. de la

    2007-10-01

    The local linearization (LL) approach has become an effective technique for the numerical integration of ordinary, random and stochastic differential equations. One of the reasons for this success is that the LL method achieves a convenient trade-off between numerical stability and computational cost. Besides, the LL method reproduces well the dynamics of nonlinear equations for which other classical methods fail. However, in the stochastic case, most of the reported works has been focused in Stochastic Differential Equations (SDE) driven by additive noise. This limits the applicability of the LL method since there is a number of interesting dynamics observed in equations with multiplicative noise. On the other hand, recent results show that commutative noise SDEs can be transformed into a random differential equation (RDE) by means of a random diffeomorfism (conjugacy). This paper takes advantages of such conjugacy property and the LL approach for defining a LL scheme for SDEs driven by commutative noise. The performance of the proposed method is illustrated by means of numerical simulations.

  4. Non-commutative holomorphic functions in elements of a Lie algebra and the absolute basis problem

    NASA Astrophysics Data System (ADS)

    Dosi, Anar A.

    2009-12-01

    We study the absolute basis problem in algebras of holomorphic functions in non-commuting variables generating a finite-dimensional nilpotent Lie algebra \\mathfrak{g}. This is motivated by J. L. Taylor's programme of non-commutative holomorphic functional calculus in the Lie algebra framework.

  5. Real hypersurfaces in the complex quadric with commuting and parallel Ricci tensor

    NASA Astrophysics Data System (ADS)

    Suh, Young Jin

    2016-08-01

    First we introduce the notion of commuting and parallel Ricci tensor for real hypersurfaces in the complex quadric Qm = SOm+2 / SO2 SOm. Then, according to the A-isotropic unit normal N, we give a complete classification of real hypersurfaces in Qm = SOm+2 / SO2 SOm with commuting and parallel Ricci tensor.

  6. 49 CFR 37.51 - Key stations in commuter rail systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Key stations in commuter rail systems. 37.51 Section 37.51 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities § 37.51 Key stations in commuter rail...

  7. Communicating with Commuters. Numerous Factors Must Be Considered To Improve Process.

    ERIC Educational Resources Information Center

    Rue, Penny

    1982-01-01

    Guidelines are given for producing a newsletter to provide information about campus programs, activities, and services of interest to commuting students. The following questions regarding newsletters are answered: (1) What information do commuting students need? (2) What format would be most effective? (3) How can news and articles be obtained?…

  8. Urban Corridor Consortium Task Force on Part-Time and Commuter Students. Final Report.

    ERIC Educational Resources Information Center

    Wisconsin Univ. Urban Corridor Consortium.

    Ways that urban corridor campuses might respond to the increasing enrollment of part-time and commuter students were reviewed by the University of Wisconsin Urban Corridor Consortium Task Force on Part-Time and Commuter Students. Members of the consortia are the following University of Wisconsin campuses: Green Bay, Milwaukee, Oshkosh, Parkside,…

  9. 77 FR 72432 - Application of Boutique Air, Inc. for Commuter Air Carrier Authority

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-05

    ... Office of the Secretary Application of Boutique Air, Inc. for Commuter Air Carrier Authority AGENCY... order finding Boutique Air, Inc., fit, willing, and able, and awarding it commuter air carrier authority... Attachment A to the order. FOR FURTHER INFORMATION CONTACT: Barbara Snoden, Air Carrier Fitness Division...

  10. [Socio-demographic and spatial structures within commuting range of Warsaw].

    PubMed

    Rakowski, W; Gocal, T

    1989-01-01

    Using official data for 1983, the authors describe the geographic and socioeconomic zones of influence that the city of Warsaw, Poland, exerts on surrounding areas. Special attention is paid to the effects of commuting for work to and from the city on regional labor markets. Some demographic characteristics of commuters are discussed. (SUMMARY IN ENG AND RUS)

  11. Assessment of commutability for candidate certified reference material ERM-BB130 "chloramphenicol in pork".

    PubMed

    Zeleny, Reinhard; Emteborg, Håkan; Schimmel, Heinz

    2010-10-01

    Chloramphenicol (CAP), an effective antibiotic against many microorganisms, is meanwhile banned in the EU for treatment of food-producing animals due to adverse health effects. The Institute for Reference Materials and Measurements (IRMM) is currently developing a certified reference material (CRM) for CAP in pork, intended for validation and method performance verifications of analytical methods. The material will be certified using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) methods and has a target CAP level around the minimum required performance limit (MRPL) of 0.3 microg/kg. To prove that the material can be applied as a quality control tool for screening methods, a commutability study was conducted, involving five commercially available enzyme-linked immunosorbent assay kits and one biosensor assay (BiaCore kit). Meat homogenates (cryo-milled wet tissue) with CAP concentrations around the MRPL and the candidate CRM (lyophilised powder) were measured by LC-MS/MS and GC-MS as well as the six screening methods. Pairwise method comparisons of results obtained for the two sample types showed that the CRM can successfully be applied as quality control (QC) sample to all six screening methods. The study suggests that ERM-BB130 is sufficiently commutable with the investigated assays and that laboratories applying one of the investigated kits therefore benefit from using ERM-BB130 to demonstrate the correctness of their results. However, differences among the assays were observed, either in the abundance of bias between screening and confirmatory LC and GC methods, the repeatability of test results, or goodness of fit between the methods. PMID:20665007

  12. Active commuting and physical activity in adolescents from Europe: results from the HELENA study.

    PubMed

    Chillón, Palma; Ortega, Francisco B; Ruiz, Jonatan R; De Bourdeaudhuij, Ilse; Martínez-Gómez, David; Vicente-Rodriguez, Germán; Widhalm, Kurt; Molnar, Dénes; Gottrand, Frédéric; González-Gross, Marcela; Ward, Dianne S; Moreno, Luis A; Castillo, Manuel J; Sjöström, Michael

    2011-05-01

    We assessed commuting patterns in adolescents from 10 European cities and examined associations with physical activity (PA). A total of 3112 adolescents were included. PA was objectively measured with accelerometry. Commuting patterns and overall PA were self-reported using questions from the International Physical Activity Questionnaire modified for adolescents (IPAQ-A). Adolescents reported to spend 30 min (15,60) [expressed as median (25th, 75th percentiles)] walking. In boys, associations between active commuting (walking and biking) and PA levels were observed for moderate, moderate-to-vigorous and overall PA. In girls, these associations were observed for moderate and moderate-to-vigorous PA (walking). Similar results were found with the IPAQ-A. We observed positive associations between overall commuting and PA levels in European adolescents, yet due to the cross-sectional study design we cannot state the direction of these. Future studies should address the causation between active commuting and PA levels.

  13. Methods and apparatus using commutative error detection values for fault isolation in multiple node computers

    DOEpatents

    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.

  14. Exploring Universal Patterns in Human Home-Work Commuting from Mobile Phone Data

    PubMed Central

    Kung, Kevin S.; Greco, Kael; Sobolevsky, Stanislav; Ratti, Carlo

    2014-01-01

    Home-work commuting has always attracted significant research attention because of its impact on human mobility. One of the key assumptions in this domain of study is the universal uniformity of commute times. However, a true comparison of commute patterns has often been hindered by the intrinsic differences in data collection methods, which make observation from different countries potentially biased and unreliable. In the present work, we approach this problem through the use of mobile phone call detail records (CDRs), which offers a consistent method for investigating mobility patterns in wholly different parts of the world. We apply our analysis to a broad range of datasets, at both the country (Portugal, Ivory Coast, and Saudi Arabia), and city (Boston) scale. Additionally, we compare these results with those obtained from vehicle GPS traces in Milan. While different regions have some unique commute time characteristics, we show that the home-work time distributions and average values within a single region are indeed largely independent of commute distance or country (Portugal, Ivory Coast, and Boston)–despite substantial spatial and infrastructural differences. Furthermore, our comparative analysis demonstrates that such distance-independence holds true only if we consider multimodal commute behaviors–as consistent with previous studies. In car-only (Milan GPS traces) and car-heavy (Saudi Arabia) commute datasets, we see that commute time is indeed influenced by commute distance. Finally, we put forth a testable hypothesis and suggest ways for future work to make more accurate and generalizable statements about human commute behaviors. PMID:24933264

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

    PubMed Central

    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

  16. Communication Networks and Perceptions of Social Support as Antecedents to College Adjustment: A Comparison between Student Commuters and Campus Residents.

    ERIC Educational Resources Information Center

    Somera, Lilnabeth P.; Ellis, Beth Hartman

    1996-01-01

    Presents a two-part study that looks at the impact of social support on college adjustment among "traditional" campus residents and commuters. Begins with a review of social support measures and the relationship between commuting and college adjustment. Finds factors critical to academic adjustment vary in the contexts of commuting students and…

  17. Mixed-state fidelity susceptibility through iterated commutator series expansion

    NASA Astrophysics Data System (ADS)

    Tonchev, N. S.

    2014-11-01

    We present a perturbative approach to the problem of computation of mixed-state fidelity susceptibility (MFS) for thermal states. The mathematical techniques used provide an analytical expression for the MFS as a formal expansion in terms of the thermodynamic mean values of successively higher commutators of the Hamiltonian with the operator involved through the control parameter. That expression is naturally divided into two parts: the usual isothermal susceptibility and a constituent in the form of an infinite series of thermodynamic mean values which encodes the noncommutativity in the problem. If the symmetry properties of the Hamiltonian are given in terms of the generators of some (finite-dimensional) algebra, the obtained expansion may be evaluated in a closed form. This issue is tested on several popular models, for which it is shown that the calculations are much simpler if they are based on the properties from the representation theory of the Heisenberg or SU(1, 1) Lie algebra.

  18. Mixed-state fidelity susceptibility through iterated commutator series expansion.

    PubMed

    Tonchev, N S

    2014-11-01

    We present a perturbative approach to the problem of computation of mixed-state fidelity susceptibility (MFS) for thermal states. The mathematical techniques used provide an analytical expression for the MFS as a formal expansion in terms of the thermodynamic mean values of successively higher commutators of the Hamiltonian with the operator involved through the control parameter. That expression is naturally divided into two parts: the usual isothermal susceptibility and a constituent in the form of an infinite series of thermodynamic mean values which encodes the noncommutativity in the problem. If the symmetry properties of the Hamiltonian are given in terms of the generators of some (finite-dimensional) algebra, the obtained expansion may be evaluated in a closed form. This issue is tested on several popular models, for which it is shown that the calculations are much simpler if they are based on the properties from the representation theory of the Heisenberg or SU(1, 1) Lie algebra. PMID:25493736

  19. Complexity and non-commutativity of learning operations on graphs.

    PubMed

    Atmanspacher, Harald; Filk, Thomas

    2006-07-01

    We present results from numerical studies of supervised learning operations in small recurrent networks considered as graphs, leading from a given set of input conditions to predetermined outputs. Graphs that have optimized their output for particular inputs with respect to predetermined outputs are asymptotically stable and can be characterized by attractors, which form a representation space for an associative multiplicative structure of input operations. As the mapping from a series of inputs onto a series of such attractors generally depends on the sequence of inputs, this structure is generally non-commutative. Moreover, the size of the set of attractors, indicating the complexity of learning, is found to behave non-monotonically as learning proceeds. A tentative relation between this complexity and the notion of pragmatic information is indicated.

  20. Reducing drag of a commuter train, using engine exhaust momentum

    NASA Astrophysics Data System (ADS)

    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%.

  1. Commuter motorcycle crashes in Malaysia: An understanding of contributing factors

    PubMed Central

    Oxley, Jennifer; Yuen, Jeremy; Ravi, Mano Deepa; Hoareau, Effie; Mohammed, Mohammed Azman Aziz; Bakar, Harun; Venkataraman, Saraswathy; Nair, Prame Kumar

    2013-01-01

    In Malaysia, two-thirds of reported workplace-related fatal and serious injury incidents are the result of commuting crashes (especially those involving motorcyclists), however, little is known about the contributing factors to these collisions. A telephone survey of 1,750 motorcyclists (1,004 adults who had been involved in a motorcycle commuting crash in the last 2 years and 746 adult motorcyclists who had not been involved in a motorcycle crash in the last 2 years) was undertaken. The contributions of a range of behavioural, attitudinal, employment and travel pattern factors to collision involvement were examined. The findings revealed that the majority of participants were licensed riders, rode substantial distances (most often for work purposes), and reported adopting safe riding practices (helmet wearing and buckling). However, there were some concerning findings regarding speeding behaviour, use of mobile phones while riding, and engaging in other risky behaviours. Participants who had been involved in a collision were younger (aged 25–29 years), had higher exposure (measured by distances travelled, frequency of riding, and riding on high volume and higher speed roads), reported higher rates of riding for work purposes, worked more shift hours and had a higher likelihood of riding at relatively high speeds compared with participants who had not been involved in a collision. Collisions generally occurred during morning and early evening hours, striking another vehicles, and during normal traffic flow. The implications of these findings for policy decisions and development of evidence-based behavioural/training interventions addressing key contributing factors are discussed. PMID:24406945

  2. Commutative law for products of infinitely large isotropic random matrices

    NASA Astrophysics Data System (ADS)

    Burda, Zdzislaw; Livan, Giacomo; Swiech, Artur

    2013-08-01

    Ensembles of isotropic random matrices are defined by the invariance of the probability measure under the left (and right) multiplication by an arbitrary unitary matrix. We show that the multiplication of large isotropic random matrices is spectrally commutative and self-averaging in the limit of infinite matrix size N→∞. The notion of spectral commutativity means that the eigenvalue density of a product ABC... of such matrices is independent of the order of matrix multiplication, for example, the matrix ABCD has the same eigenvalue density as ADCB. In turn, the notion of self-averaging means that the product of n independent but identically distributed random matrices, which we symbolically denote by AAA..., has the same eigenvalue density as the corresponding power An of a single matrix drawn from the underlying matrix ensemble. For example, the eigenvalue density of ABCCABC is the same as that of A2B2C3. We also discuss the singular behavior of the eigenvalue and singular value densities of isotropic matrices and their products for small eigenvalues λ→0. We show that the singularities at the origin of the eigenvalue density and of the singular value density are in one-to-one correspondence in the limit N→∞: The eigenvalue density of an isotropic random matrix has a power-law singularity at the origin ˜|λ|-s with a power s∈(0,2) when and only when the density of its singular values has a power-law singularity ˜λ-σ with a power σ=s/(4-s). These results are obtained analytically in the limit N→∞. We supplement these results with numerical simulations for large but finite N and discuss finite-size effects for the most common ensembles of isotropic random matrices.

  3. Quantum groups, non-commutative differential geometry and applications

    SciTech Connect

    Schupp, P

    1993-12-09

    The topic of this thesis is the development of a versatile and geometrically motivated differential calculus on non-commutative or quantum spaces, providing powerful but easy-to-use mathematical tools for applications in physics and related sciences. A generalization of unitary time evolution is proposed and studied for a simple 2-level system, leading to non-conservation of microscopic entropy, a phenomenon new to quantum mechanics. A Cartan calculus that combines functions, forms, Lie derivatives and inner derivations along general vector fields into one big algebra is constructed for quantum groups and then extended to quantum planes. The construction of a tangent bundle on a quantum group manifold and an BRST type approach to quantum group gauge theory are given as further examples of applications. The material is organized in two parts: Part I studies vector fields on quantum groups, emphasizing Hopf algebraic structures, but also introducing a ``quantum geometric`` construction. Using a generalized semi-direct product construction we combine the dual Hopf algebras A of functions and U of left-invariant vector fields into one fully bicovariant algebra of differential operators. The pure braid group is introduced as the commutant of {Delta}(U). It provides invariant maps A {yields} U and thereby bicovariant vector fields, casimirs and metrics. This construction allows the translation of undeformed matrix expressions into their less obvious quantum algebraic counter parts. We study this in detail for quasitriangular Hopf algebras, giving the determinant and orthogonality relation for the ``reflection`` matrix. Part II considers the additional structures of differential forms and finitely generated quantum Lie algebras -- it is devoted to the construction of the Cartan calculus, based on an undeformed Cartan identity.

  4. Coulomb problem in non-commutative quantum mechanics

    SciTech Connect

    Galikova, Veronika; Presnajder, Peter

    2013-05-15

    The aim of this paper is to find out how it would be possible for space non-commutativity (NC) to alter the quantum mechanics (QM) solution of the Coulomb problem. The NC parameter {lambda} is to be regarded as a measure of the non-commutativity - setting {lambda}= 0 which means a return to the standard quantum mechanics. As the very first step a rotationally invariant NC space R{sub {lambda}}{sup 3}, an analog of the Coulomb problem configuration space (R{sup 3} with the origin excluded) is introduced. R{sub {lambda}}{sup 3} is generated by NC coordinates realized as operators acting in an auxiliary (Fock) space F. The properly weighted Hilbert-Schmidt operators in F form H{sub {lambda}}, a NC analog of the Hilbert space of the wave functions. We will refer to them as 'wave functions' also in the NC case. The definition of a NC analog of the hamiltonian as a hermitian operator in H{sub {lambda}} is one of the key parts of this paper. The resulting problem is exactly solvable. The full solution is provided, including formulas for the bound states for E < 0 and low-energy scattering for E > 0 (both containing NC corrections analytic in {lambda}) and also formulas for high-energy scattering and unexpected bound states at ultra-high energy (both containing NC corrections singular in {lambda}). All the NC contributions to the known QM solutions either vanish or disappear in the limit {lambda}{yields} 0.

  5. Simulation of population-based commuter exposure to NO₂ using different air pollution models.

    PubMed

    Ragettli, Martina S; Tsai, Ming-Yi; Braun-Fahrländer, Charlotte; de Nazelle, Audrey; Schindler, Christian; Ineichen, Alex; Ducret-Stich, Regina E; Perez, Laura; Probst-Hensch, Nicole; Künzli, Nino; Phuleria, Harish C

    2014-05-12

    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.

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

    PubMed Central

    Ragettli, Martina S.; Tsai, Ming-Yi; Braun-Fahrländer, Charlotte; de Nazelle, Audrey; Schindler, Christian; Ineichen, Alex; Ducret-Stich, Regina E.; Perez, Laura; Probst-Hensch, Nicole; Künzli, Nino; Phuleria, Harish C.

    2014-01-01

    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. PMID:24823664

  7. Photography of the commutation spark using a high-speed camera

    NASA Astrophysics Data System (ADS)

    Hanazawa, Tamio; Egashira, Torao; Tanaka, Yasuhiro; Egoshi, Jun

    1997-12-01

    In the single-phase AC commutator motor (known as a universal motor), which is widely used in cleaners, electrical machines, etc., some problems generated by commutation sparks are wear on the brush and noise impediments. We have therefore attempted to use a high-speed camera to elucidate the commutation spark mechanism visually. The high-speed camera that we used is capable of photographing at 5,000 - 20,000,000 frames/s. Selection of a trigger module can be obtained from the operation unit and the exterior triggering signal. In this paper, we proposed an exterior trigger method that involved opening a hole of several millimeters across in the motor and using argon laser light, so that commutator segments may be photographed in position; we then conducted the experiment. This method enabled us to photograph the motor's commutator segment from any position, and we were able to confirm spark generation at every other commutator segment. Furthermore, after confirming the spark generation position of the commutator segment, we next attempted to accelerate the photographing speed to obtain more detailed photography of the moment of spark generation; we then prepared our report.

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

    PubMed

    Djurhuus, Sune; Hansen, Henning S; Aadahl, Mette; Glümer, Charlotte

    2014-12-05

    Active commuting provides routine-based regular physical activity which can reduce the risk of chronic diseases. Using public transportation involves some walking or cycling to a transit stop, transfers and a walk to the end location and users of public transportation have been found to accumulate more moderate physical activity than non-users. Understanding how public transportation characteristics are associated with active transportation is thus important from a public health perspective. This study examines the associations between objective measures of access to public transportation and self-reported active commuting. Self-reported time spent either walking or cycling commuting each day and the distance to workplace were obtained for adults aged 16 to 65 in the Danish National Health Survey 2010 (n = 28,928). Access to public transportation measures were computed by combining GIS-based road network distances from home address to public transit stops an integrating their service level. Multilevel logistic regression was used to examine the association between access to public transportation measures and active commuting. Distance to bus stop, density of bus stops, and number of transport modes were all positively associated with being an active commuter and with meeting recommendations of physical activity. No significant association was found between bus services at the nearest stop and active commuting. The results highlight the importance of including detailed measurements of access to public transit in order to identify the characteristics that facilitate the use of public transportation and active commuting.

  9. Commutability of the First World Health Organization International Standard for Human Cytomegalovirus

    PubMed Central

    Preiksaitis, J.; Tong, Y.; Pang, X.; Sun, Y.; Tang, L.; Cook, L.; Pounds, S.; Fryer, J.; Caliendo, A. M.

    2015-01-01

    Quantitative detection of cytomegalovirus (CMV) DNA has become a standard part of care for many groups of immunocompromised patients; recent development of the first WHO international standard for human CMV DNA has raised hopes of reducing interlaboratory variability of results. Commutability of reference material has been shown to be necessary if such material is to reduce variability among laboratories. Here we evaluated the commutability of the WHO standard using 10 different real-time quantitative CMV PCR assays run by eight different laboratories. Test panels, including aliquots of 50 patient samples (40 positive samples and 10 negative samples) and lyophilized CMV standard, were run, with each testing center using its own quantitative calibrators, reagents, and nucleic acid extraction methods. Commutability was assessed both on a pairwise basis and over the entire group of assays, using linear regression and correspondence analyses. Commutability of the WHO material differed among the tests that were evaluated, and these differences appeared to vary depending on the method of statistical analysis used and the cohort of assays included in the analysis. Depending on the methodology used, the WHO material showed poor or absent commutability with up to 50% of assays. Determination of commutability may require a multifaceted approach; the lack of commutability seen when using the WHO standard with several of the assays here suggests that further work is needed to bring us toward true consensus. PMID:26269622

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

    PubMed Central

    Stigell, Erik; Schantz, Peter

    2015-01-01

    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: 231–389) 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. PMID:26690193

  11. Silicon controlled rectifier polyphase bridge inverter commutated with gate-turn-off thyristor

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    A polyphase SCR inverter (10) having N switching poles, each comprised of two SCR switches (1A, 1B; 2A, 2B . . . NA, NB) and two diodes (D1B; D1B; D2A, D2B . . . DNA, DNB) in series opposition with saturable reactors (L1A, L1B; L2A, L2B . . . LNA, LNB) connecting the junctions between the SCR switches and diodes to an output terminal (1, 2 . . . 3) is commutated with only one GTO thyristor (16) connected between the common negative terminal of a dc source and a tap of a series inductor (14) connected to the positive terminal of the dc source. A clamp winding (22) and diode (24) are provided, as is a snubber (18) which may have its capacitance (c) sized for maximum load current divided into a plurality of capacitors (C.sub.1, C.sub.2 . . . C.sub.N), each in series with an SCR switch S.sub.1, S.sub.2 . . . S.sub.N). The total capacitance may be selected by activating selected switches as a function of load current. A resistor 28 and SCR switch 26 shunt reverse current when the load acts as a generator, such as a motor while braking.

  12. NYPA/TH!NK Clean Commute Program Final Report - Inception through December 2004

    SciTech Connect

    James Francfort; Don Karner

    2005-11-01

    The Clean Commute Program uses TH!NK city electric vehicles from Ford Motor Company’s electric vehicle group, TH!NK Mobility, to demonstrate the feasibility of using electric transportation in urban applications. Suburban New York City railroad commuters use the TH!NK city vehicles to commute from their private residences to railroad stations, where they catch commuter trains into New York City. Electric vehicle charging infrastructure for the TH!NK city vehicles is located at the commuters’ private residences as well as seven train stations. Ford leased at total of 97 TH!NK city electric vehicles to commuters from Westchester, Putnam, Rockland, Queens, Nassau, and Suffolk counties for $199 per month. First Clean Commute Program vehicle deliveries occurred late in 2001, with data collection commencing in February 2002. Through May, 2004, 24 of the lessees have returned their vehicles to Ford and no longer participate in the Clean Commute Program. Reasons given for leaving the Program include relocation out of the Program area, change in employment status, change in commuting status, and, in a few cases, dissatisfaction with the vehicle. Additionally, 13 vehicles were returned to Ford when the lease was completed. In August 2002, Ford announced that it was ceasing production of the TH!NK city and would not extend any TH!NK city leases. Mileage accumulation dropped in the last quarter of the program as vehicle leases were returned to Ford. The impact of the program overall was significant as participants in the Clean Commute Program drove their vehicles over 406,074 miles, avoiding the use of over 18,887 gallons of gasoline. During the active portion of the program, the TH!NK city vehicles were driven an average of between 180 and 230 miles per month. Over 95% of all trips taken with the TH!NK city vehicles replaced trips previously taken in gasoline vehicles. This report covers the period from Program inception through December 2004.

  13. NYPA/TH!NK Clean Commute Program Report – Inception Through May 2004

    SciTech Connect

    Don Karner; James Francfort; Randall Solomon

    2004-11-01

    The Clean Commute Program uses TH!NK city electric vehicles from Ford Motor Company’s electric vehicle group, TH!NK Mobility, to demonstrate the feasibility of using electric vehicles for transportation in urban applications. Suburban New York City railroad commuters use the TH!NK city vehicles to commute from their private residences to railroad stations, where they catch commuter trains into New York City. Electric vehicle charging infrastructure for the TH!NK city vehicles is located at the commuters’ private residences as well as seven train stations. Ford leased 97 TH!NK city electric vehicles to commuters from Westchester, Putnam, Rockland, Queens, Nassau, and Suffolk counties for $199 per month per vehicle. The first Clean Commute Program vehicle deliveries occurred late in 2001, with data collection commencing in February 2002. Through May 2004, 24 of the lessees have returned their vehicles to Ford and no longer participate in the Clean Commute Program. Reasons given for returning the vehicles include relocation out of the Program area, change in employment status, change in commuting status, and, in a few cases, dissatisfaction with the vehicle. Additionally, 13 vehicles have been returned to Ford as their leases have completed. In August 2002, Ford announced that it was ceasing production of the TH!NK city and would not extend any TH!NK city leases. Through May 2004, participants in the Clean Commute Program have driven their vehicles over 370,000 miles, avoiding the use of over 17,000 gallons of gasoline. The TH!NK city vehicles are driven an average of between 180 and 230 miles per month, and over 95% of all trips taken with the TH!NK city vehicles replace trips previously taken in gasoline vehicles. This report covers the period from Program inception through May 2004.

  14. Design of a digital ride quality augmentation system for commuter aircraft

    NASA Technical Reports Server (NTRS)

    Hammond, T. A.; Amin, S. P.; Paduano, J. D.; Downing, D. R.

    1984-01-01

    Commuter aircraft typically have low wing loadings, and fly at low altitudes, and so they are susceptible to undesirable accelerations caused by random atmospheric turbulence. Larger commercial aircraft typically have higher wing loadings and fly at altitudes where the turbulence level is lower, and so they provide smoother rides. This project was initiated based on the goal of making the ride of the commuter aircraft as smooth as the ride experienced on the major commercial airliners. The objectives of this project were to design a digital, longitudinal mode ride quality augmentation system (RQAS) for a commuter aircraft, and to investigate the effect of selected parameters on those designs.

  15. Landau-like Atomic Problem on a Non-commutative Phase Space

    NASA Astrophysics Data System (ADS)

    Mamat, Jumakari; Dulat, Sayipjamal; Mamatabdulla, Hekim

    2016-06-01

    We study the motion of a neutral particle in symmetric gauge and in the framework of non-commutative Quantum Mechanics. Starting from the corresponding Hamiltonian we derive the eigenfunction and eigenvalues.

  16. 20 CFR 702.142 - Commutation of payments; aliens not residents or about to become nonresidents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... surviving spouse or child or children, to surviving father or mother whom the employee has supported, either..., OWCP, may, at his option, or upon the application of the insurance carrier he shall, commute all...

  17. Commute trip reduction in Washington: Base year worksite characteristics and programs

    SciTech Connect

    Dodds, D.

    1995-02-01

    Employers in Washington`s eight most populous counties are engaged in an effort to reduce their employees` use of single occupant automobiles for commuting. This report documents the status of those employers at the beginning of the Commute Trip Reduction (CTR) program as a basis for evaluating the impacts of the program. The first section provides a brief exploration of the Washington CTR Law and a history of the first steps in its implementation. The second section presents a summary of the characteristics of the worksites affected by the law. The CTR Law calls for reductions in single occupant vehicle (SOV) commuting and in vehicle miles traveled (VMT). The third section of this report presents baseline measurements of SOV and VMT and goals for reducing them. The fourth section provides summary information on the first year of programs employers planned to implement. The final section very briefly outlines actions the Commute Trip Reduction law calls for between 1995 and 1999.

  18. Proceedings of the Monterey Conference on Planning for Rotorcraft and Commuter Air Transportation

    NASA Technical Reports Server (NTRS)

    Stockwell, W. L.

    1983-01-01

    Planning and technological issues involved in rotorcraft and commuter fixed-wing air transportation are discussed. Subject areas include the future community environment, aircraft technology, community transportation planning, and regulatory perspectives.

  19. Research and technology program perspectives for general aviation and commuter aircraft

    NASA Technical Reports Server (NTRS)

    Bauchspies, J. S.; Simpson, W. E.

    1982-01-01

    The uses, benefits, and technology needs of the U.S. general aviation industry were studied in light of growing competition from foreign general aviation manufacturers, especially in the commuter and business jet aircraft markets.

  20. Quantum Groups, Non-Commutative Differential Geometry and Applications

    NASA Astrophysics Data System (ADS)

    Schupp, Peter

    The topic of this thesis is the development of a versatile and geometrically motivated differential calculus on non-commutative or quantum spaces, providing powerful but easy-to-use mathematical tools for applications in physics and related sciences. A generalization of unitary time evolution is proposed and studied for a simple 2-level system, leading to non-conservation of microscopic entropy, a phenomenon new to quantum mechanics. A Cartan calculus that combines functions, forms, Lie derivatives and inner derivations along general vector fields into one big algebra is constructed for quantum groups and then extended to quantum planes. The construction of a tangent bundle on a quantum group manifold and an BRST type approach to quantum group gauge theory are given as further examples of applications. The material is organized in two parts: Part I studies vector fields on quantum groups, emphasizing Hopf algebraic structures, but also introducing a 'quantum geometric' construction. Using a generalized semi-direct product construction we combine the dual Hopf algebras {cal A} of functions and {cal U} of left-invariant vector fields into one fully bicovariant algebra of differential operators. The pure braid group is introduced as the commutant of Delta({cal U}). It provides invariant maps {cal A} to{cal U} and thereby bicovariant vector fields, casimirs and metrics. This construction allows the translation of undeformed matrix expressions into their less obvious quantum algebraic counter parts. We study this in detail for quasitriangular Hopf algebras, giving the determinant and orthogonality relation for the 'reflection' matrix. Part II considers the additional structures of differential forms and finitely generated quantum Lie algebras--it is devoted to the construction of the Cartan calculus, based on an undeformed Cartan identity. We attempt a classification of various types of quantum Lie algebras and present a fairly general example for their construction

  1. Exposure to traffic pollution, acute inflammation and autonomic response in a panel of car commuters

    PubMed Central

    Sarnat, Jeremy A.; Golan, Rachel; Greenwald, Roby; Raysoni, Amit U.; Kewada, Priya; Winquist, Andrea; Sarnat, Stefanie E.; Flanders, W. Dana; Mirabelli, Maria C.; Zora, Jennifer E.; Bergin, Michael H.; Yip, Fuyuen

    2015-01-01

    Background Exposure to traffic pollution has been linked to numerous adverse health endpoints. Despite this, limited data examining traffic exposures during realistic commutes and acute response exists. Objectives: We conducted the Atlanta Commuters Exposures (ACE-1) Study, an extensive panel-based exposure and health study, to measure chemically-resolved in-vehicle exposures and corresponding changes in acute oxidative stress, lipid peroxidation, pulmonary and systemic inflammation and autonomic response. Methods We recruited 42 adults (21 with and 21 without asthma) to conduct two 2-h scripted highway commutes during morning rush hour in the metropolitan Atlanta area. A suite of in-vehicle particulate components were measured in the subjects’ private vehicles. Biomarker measurements were conducted before, during, and immediately after the commutes and in 3 hourly intervals after commutes. Results At measurement time points within 3 h after the commute, we observed mild to pronounced elevations relative to baseline in exhaled nitric oxide, C-reactive-protein, and exhaled malondialdehyde, indicative of pulmonary and systemic inflammation and oxidative stress initiation, as well as decreases relative to baseline levels in the time-domain heart-rate variability parameters, SDNN and rMSSD, indicative of autonomic dysfunction. We did not observe any detectable changes in lung function measurements (FEV1, FVC), the frequency-domain heart-rate variability parameter or other systemic biomarkers of vascular injury. Water soluble organic carbon was associated with changes in eNO at all post-commute time-points (p < 0.0001). Conclusions Our results point to measureable changes in pulmonary and autonomic biomarkers following a scripted 2-h highway commute. PMID:24906070

  2. Student's exposure to volatile organic compounds while commuting by motorcycle and bus in Taipei City

    SciTech Connect

    Chan, C.C.; Lin, S.H.; Her, G.R. )

    1993-09-01

    This study examined student's exposure to volatile organic compounds (VOCs) while commuting by bus and motorcycle in Taipei, Taiwan in the winter of 1992. A total of 19 target C5-C10 VOCs on three most frequently used commuting routes were collected on Tenax-GC adsorbent tubes. The VOCs were desorbed by thermal desorption method and analyzed by GC-MS. The most abundant VOC exposure experienced by commuters was to toluene. Several alkylated benzenes, such as propyl benzenes, ethyl-methyl-benzenes and trimethyl-benzenes, were relatively abundant on the roads in Taipei. The mean benzene concentration measured in buses was 173 micrograms/m3 and motorcycles. On the average, the commuters in Taipei experienced about three to eight times higher VOC concentrations than the commuters in Los Angeles, California. Higher VOC concentrations were measured on motorcycles than in buses. The VOC concentrations were not significantly different between morning and afternoon commutes, nor among the three commuting routes. VOC concentrations measured in classroom at three schools in downtown Taipei did not vary significantly on each sampling day. However, at each school the in-classroom VOC concentrations varied significantly over the six consecutive sampling days. The VOC concentrations measured on the roads were about five times higher than those measured in the school classrooms in the city. Moderate to high correlations were found among most of the measurements of the 19 VOCs. The survey questionnaire indicated that daily commuting time ranged from 45 minutes for elementary school students to 95 minutes for vocational school students.

  3. Regularization of two-dimensional supersymmetric Yang-Mills theory via non-commutative geometry

    NASA Astrophysics Data System (ADS)

    Valavane, K.

    2000-11-01

    The non-commutative geometry is a possible framework to regularize quantum field theory in a non-perturbative way. This idea is an extension of the lattice approximation by non-commutativity that allows us to preserve symmetries. The supersymmetric version is also studied and more precisely in the case of the Schwinger model on a supersphere. This paper is a generalization of this latter work to more general gauge groups.

  4. Quantization maps, algebra representation, and non-commutative Fourier transform for Lie groups

    SciTech Connect

    Guedes, Carlos; Oriti, Daniele; Raasakka, Matti

    2013-08-15

    The phase space given by the cotangent bundle of a Lie group appears in the context of several models for physical systems. A representation for the quantum system in terms of non-commutative functions on the (dual) Lie algebra, and a generalized notion of (non-commutative) Fourier transform, different from standard harmonic analysis, has been recently developed, and found several applications, especially in the quantum gravity literature. We show that this algebra representation can be defined on the sole basis of a quantization map of the classical Poisson algebra, and identify the conditions for its existence. In particular, the corresponding non-commutative star-product carried by this representation is obtained directly from the quantization map via deformation quantization. We then clarify under which conditions a unitary intertwiner between such algebra representation and the usual group representation can be constructed giving rise to the non-commutative plane waves and consequently, the non-commutative Fourier transform. The compact groups U(1) and SU(2) are considered for different choices of quantization maps, such as the symmetric and the Duflo map, and we exhibit the corresponding star-products, algebra representations, and non-commutative plane waves.

  5. Modeling the Commuting Travel Activities within Historic Districts in Chinese Cities

    PubMed Central

    Yin, Fengjun; Hu, Qizhou

    2014-01-01

    The primary objective of this study is to analyze the characteristics of commuting activities within the historical districts in cities of China. The impacts of various explanatory variables on commuters' travels are evaluated using the structural equation modeling (SEM) approach. The household survey was conducted in the historical districts in Yangzhou, China. Based on the data, various individual and household attributes were considered exogenous variables, while the subsistence activity characteristics, travel times, numbers of three typical home-based trip chains, trip chains, and travel mode were considered as the endogenous variables. Commuters in our study were classified into two main groups according to their working location, which were the commuters in the historic district and those out of the district. The modeling results show that several individual and household attributes of commuters in historic district have significant impacts on the characteristics of travel activities. Additionally, the characteristics of travel activities within the two groups are quite different, and the contributing factors related to commuting travels are different as well. PMID:25435864

  6. Lightweight diesel engine designs for commuter type aircraft

    NASA Technical Reports Server (NTRS)

    Brouwers, A. P.

    1981-01-01

    Conceptual designs and performance of advanced technology lightweight diesel engines, suitable for commuter type aircraft power plants are defined. Two engines are discussed, a 1491 kW (2000 SHP) eight-cylinder engine and a 895 kW (1200 SHP) six-cylinder engine. High performance and related advanced technologies are proposed such as insulated cylinders, very high injection pressures and high compressor and turbine efficiencies. The description of each engine includes concept drawings, a performance analysis, and weight data. Fuel flow data are given for full and partial power up to 7620m altitude. The performance data are also extrapolated over a power range from 671 kW(900SHP) to 1864 kW (2500 SHP). The specific fuel consumption of the 1491 kW (2000 SHP) engine is 182 g/hWh (.299 lb/HPh) at cruise altitude, its weight 620 kg (1365 lb.) and specific weight .415 kg/kW (.683 lb/HP). The specific fuel consumption of the 895 kW (1200 SHP) engine is 187 g/hWh (.308 lb/HPh) at cruise altitude, its weight 465 kg (1025 lb.) and specific weight .520 kg/kW (.854 lb/HP).

  7. Study of advanced rotary combustion engines for commuter aircraft

    NASA Technical Reports Server (NTRS)

    Berkowitz, M.; Jones, C.; Myers, D.

    1983-01-01

    Performance, weight, size, and maintenance data for advanced rotary aircraft engines suitable for comparative commuter aircraft system evaluation studies of alternate engine candidates are provided. These are turbocharged, turbocompounded, direct injected, stratified charge rotary engines. Hypothetical engines were defined (an RC4-74 at 895 kW and an RC6-87 at 1490 kW) based on the technologies and design approaches used in the highly advanced engine of a study of advanced general aviation rotary engines. The data covers the size range of shaft power from 597 kW (800 hp) to 1865 kW (2500 hp) and is in the form of drawings, tables, curves and written text. These include data on internal geometry and configuration, installation information, turbocharging and turbocompounding arrangements, design features and technologies, engine cooling, fuels, scaling for weight size BSFC and heat rejection for varying horsepower, engine operating and performance data, and TBO and maintenance requirements. The basic combustion system was developed and demonstrated; however the projected power densities and performance efficiencies require increases in engine internal pressures, thermal loading, and rotative speed.

  8. Factors associated with active commuting to work among women.

    PubMed

    Bopp, Melissa; Child, Stephanie; Campbell, Matthew

    2014-01-01

    Active commuting (AC), the act of walking or biking to work, has notable health benefits though rates of AC remain low among women. This study used a social-ecological framework to examine the factors associated with AC among women. A convenience sample of employed, working women (n = 709) completed an online survey about their mode of travel to work. Individual, interpersonal, institutional, community, and environmental influences were assessed. Basic descriptive statistics and frequencies described the sample. Simple logistic regression models examined associations with the independent variables with AC participation and multiple logistic regression analysis determined the relative influence of social ecological factors on AC participation. The sample was primarily middle-aged (44.09±11.38 years) and non-Hispanic White (92%). Univariate analyses revealed several individual, interpersonal, institutional, community and environmental factors significantly associated with AC. The multivariable logistic regression analysis results indicated that significant factors associated with AC included number of children, income, perceived behavioral control, coworker AC, coworker AC normative beliefs, employer and community supports for AC, and traffic. The results of this study contribute to the limited body of knowledge on AC participation for women and may help to inform gender-tailored interventions to enhance AC behavior and improve health.

  9. A lightweight electronically commutated dc motor for electric passenger vehicles

    NASA Technical Reports Server (NTRS)

    Echolds, E. F.; Walla, P. S.

    1982-01-01

    A functional model breadboard converter and a rare-earth-cobalt, permanent magnet motor; as well as an engineering model converter and PM motor suitable for vehicle installations were developed and tested. The converter and motor achieved an 88% peak efficiency, a maximum output of 26 kW at 26,000 rpm, and a continuous rating of 15 kW. The system also generated power to the source during braking, with a demonstrated peak power available at the converter terminals of approximately 26 kW at 88% efficiency. Major conclusions include: (1) the SAE J227a(D) driving cycle efficiency for the converter/motor is 86% to 88% when energy available for recovery at the converter terminals is included; (2) the converter initial cost is approximately five times that of the permanent magnet motor, but can be reduced by means of LSI logic and integrated liquid cooled semiconductor packages; and (3) an electronically commutated motor with a liquid cooled converter will operate reliably without service or maintenance for the life of a passenger vehicle.

  10. Representations of Canonical Commutation Relations Describing Infinite Coherent States

    NASA Astrophysics Data System (ADS)

    Joye, Alain; Merkli, Marco

    2016-10-01

    We investigate the infinite volume limit of quantized photon fields in multimode coherent states. We show that for states containing a continuum of coherent modes, it is mathematically and physically natural to consider their phases to be random and identically distributed. The infinite volume states give rise to Hilbert space representations of the canonical commutation relations which we construct concretely. In the case of random phases, the representations are random as well and can be expressed with the help of Itô stochastic integrals. We analyze the dynamics of the infinite state alone and the open system dynamics of small systems coupled to it. We show that under the free field dynamics, initial phase distributions are driven to the uniform distribution. We demonstrate that coherences in small quantum systems, interacting with the infinite coherent state, exhibit Gaussian time decay. The decoherence is qualitatively faster than the one caused by infinite thermal states, which is known to be exponentially rapid only. This emphasizes the classical character of coherent states.

  11. Computational quantum-classical boundary of noisy commuting quantum circuits.

    PubMed

    Fujii, Keisuke; Tamate, Shuhei

    2016-01-01

    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. PMID:27189039

  12. Computational quantum-classical boundary of noisy commuting quantum circuits

    NASA Astrophysics Data System (ADS)

    Fujii, Keisuke; Tamate, Shuhei

    2016-05-01

    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.

  13. Factors associated with active commuting to work among women.

    PubMed

    Bopp, Melissa; Child, Stephanie; Campbell, Matthew

    2014-01-01

    Active commuting (AC), the act of walking or biking to work, has notable health benefits though rates of AC remain low among women. This study used a social-ecological framework to examine the factors associated with AC among women. A convenience sample of employed, working women (n = 709) completed an online survey about their mode of travel to work. Individual, interpersonal, institutional, community, and environmental influences were assessed. Basic descriptive statistics and frequencies described the sample. Simple logistic regression models examined associations with the independent variables with AC participation and multiple logistic regression analysis determined the relative influence of social ecological factors on AC participation. The sample was primarily middle-aged (44.09±11.38 years) and non-Hispanic White (92%). Univariate analyses revealed several individual, interpersonal, institutional, community and environmental factors significantly associated with AC. The multivariable logistic regression analysis results indicated that significant factors associated with AC included number of children, income, perceived behavioral control, coworker AC, coworker AC normative beliefs, employer and community supports for AC, and traffic. The results of this study contribute to the limited body of knowledge on AC participation for women and may help to inform gender-tailored interventions to enhance AC behavior and improve health. PMID:24512572

  14. Computational quantum-classical boundary of noisy commuting quantum circuits

    PubMed Central

    Fujii, Keisuke; Tamate, Shuhei

    2016-01-01

    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. PMID:27189039

  15. Etude D'onduleurs Triphases a Haute Frequence et a Commutation Douce

    NASA Astrophysics Data System (ADS)

    Cheriti, Ahmed

    This thesis contributes to the increase of the application field of resonant converters which until now was limited to small switch mode power supplies. The approaches used in this case cannot be straight forward applied to the inverters which operate in several quadrants and where the power involved is much higher. Therefore, the integration of the resonance techniques to the inverters necessitates a separate study and that is what we are trying to do in this work. The configuration that we wanted to develop should have two major features. Firstly, it should not generate any overvoltage on the power semiconductors. Secondly, it should be able to operate in pulse width modulation at high frequency. Consequently an approach such as the recently proposed resonant dc link inverter will not be considered. After analysing a few structures, we selected a configuration which met our specifications. This configuration was called: the pulse width Modulation Resonant Pole Inverter (MRPI) and it will the subject for a detailed study in this thesis. Basically, this study includes: the applications, the operating sequences, the design, the possible modifications, the base drive circuits, the control circuit, the experimentation and the efficiency calculations. In this study, the state-plane technique is extensively used. This technique simplifies the study of second order systems with low damping factor. For example, we use the state plane while determining: (1) the operating sequences and their duration, (2) the voltage and current stresses on the power semiconductors, (3) the operating limits. The experimental tests were held on a three-phase asynchronous machine based variable speed drive controlled under the V/F constant low. The control circuit implementing this law was elaborated with the help of original digital circuits which will be the subject for a detailed description too. Finally, we will show in this thesis that the proposed configuration contributes substantially

  16. Exposure of motorcycle, car and bus commuters to carbon monoxide on a main road in the Tel Aviv metropolitan area, Israel.

    PubMed

    Potchter, Oded; Oz, Meirav; Brenner, Shmuel; Yaakov, Yaron; Schnell, Izhak

    2014-12-01

    Short-term personal exposure of passengers in different types of motor vehicles to carbon monoxide was investigated in an intensively used main road in Israel's Tel Aviv metropolitan area. According to monitoring stations of the Ministry for Environmental Protection (MEP), concentrations of carbon monoxide (CO) along the road, at a height of 3 m above pedestrian level, in the Tel Aviv metropolitan area, are currently very low. However, these measurements do not reflect the actual exposure of commuters, which were the main objective of this study. Four vehicle types/travel modes were investigated: private cars with closed windows, private cars with open windows, motorcycles, and buses. The commuter CO average exposure was the accumulative exposure divided by the duration of the sampling taken along the route, for each type of vehicles. The results showed that commuters in cars with closed windows were exposed to the highest mean CO level, 27.2 ppm, for a period of 38 min; those in a car with open windows, to 19.7 ppm for 38 min; motorcycle riders, to 12.8 ppm, for 17 min; and bus users were exposed to the lowest mean pollution level, of only 3.6 ppm, for 25 min. Thus, CO values of 1 to 3 ppm, as measured at an MEP adjacent monitoring station, may indicate the exposure to CO pollution of area residents, but do not represent the actual exposure of commuters on the congested main road.

  17. Groenewold-Moyal product, α*-cohomology, and classification of translation-invariant non-commutative structures

    SciTech Connect

    Varshovi, Amir Abbass

    2013-07-15

    The theory of α*-cohomology is studied thoroughly and it is shown that in each cohomology class there exists a unique 2-cocycle, the harmonic form, which generates a particular Groenewold-Moyal star product. This leads to an algebraic classification of translation-invariant non-commutative structures and shows that any general translation-invariant non-commutative quantum field theory is physically equivalent to a Groenewold-Moyal non-commutative quantum field theory.

  18. Non-commutative U(1) gauge theory on \\mth{\\mathbb{R}^4_{\\Theta}} with oscillator term and BRST symmetry

    NASA Astrophysics Data System (ADS)

    Blaschke, D. N.; Grosse, H.; Schweda, M.

    2007-09-01

    Inspired by the renormalizability of the non-commutative Φ4 model with added oscillator term, we formulate a non-commutative gauge theory, where the oscillator enters as a gauge fixing term in a BRST invariant manner. All propagators turn out to be essentially given by the Mehler kernel and the bilinear part of the action is invariant under the Langmann-Szabo duality. The model is a promising candidate for a renormalizable non-commutative U(1) gauge theory.

  19. Commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi.

    PubMed

    Kumar, Pramod; Gupta, N C

    2016-01-15

    A public health concern is to understand the linkages between specific pollution sources and adverse health impacts. Commuting can be viewed as one of the significant-exposure activity in high-vehicle density areas. This paper investigates the commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi, India. Air pollution levels are significantly contributed by automobile exhaust and also in-vehicle exposure can be higher sometime than ambient levels. Motorcycle, auto rickshaw, car and bus were selected to study particles concentration along two routes in Delhi between Kashmere Gate and Dwarka. The bus and auto rickshaw were running on compressed natural gas (CNG) while the car and motorcycle were operated on gasoline fuel. Aerosol spectrometer was employed to measure inhalable, thoracic and alveolic particles during morning and evening rush hours for five weekdays. From the study, we observed that the concentration levels of these particles were greatly influenced by transportation modes. Concentrations of inhalable particles were found higher during morning in auto rickshaw (332.81 ± 90.97 μg/m(3)) while the commuter of bus exhibited higher exposure of thoracic particles (292.23 ± 110.45 μg/m(3)) and car commuters were exposed to maximum concentrations of alveolic particles (222.37 ± 26.56 μg/m(3)). We observed that in evening car commuters experienced maximum concentrations of all sizes of particles among the four commuting modes. Interestingly, motorcycle commuters were exposed to lower levels of inhalable and thoracic particles during morning and evening hours as compared to other modes of transport. The mean values were found greater than the median values for all the modes of transport suggesting that positive skewed distributions are characteristics of naturally occurring phenomenon.

  20. Modification of Traffic-related Respiratory Response by Asthma Control in a Population of Car Commuters

    PubMed Central

    Mirabelli, Maria C.; Golan, Rachel; Greenwald, Roby; Raysoni, Amit U.; Holguin, Fernando; Kewada, Priya; Winquist, Andrea; Flanders, W. Dana; Sarnat, Jeremy A.

    2015-01-01

    Background Effects of traffic-related exposures on respiratory health are well documented, but little information is available about whether asthma control influences individual susceptibility. We analyzed data from the Atlanta Commuter Exposure study to evaluate modification of associations between rush-hour commuting, in-vehicle air pollution, and selected respiratory health outcomes by asthma control status. Methods Between 2009 and 2011, 39 adults participated in Atlanta Commuter Exposure, and each conducted two scripted rush-hour highway commutes. In-vehicle particulate components were measured during all commutes. Among adults with asthma, we evaluated asthma control by questionnaire and spirometry. Exhaled nitric oxide, forced expiratory volume in 1 second (FEV1), and other metrics of respiratory health were measured precommute and 0, 1, 2, and 3 hours postcommute. We used mixed effects linear regression to evaluate associations between commute-related exposures and postcommute changes in metrics of respiratory health by level of asthma control. Results We observed increased exhaled nitric oxide across all levels of asthma control compared with precommute measurements, with largest postcommute increases observed among participants with below-median asthma control (2 hours postcommute: 14.6% [95% confidence interval {CI} = 5.7, 24.2]; 3 hours postcommute: 19.5% [95% CI = 7.8, 32.5]). No associations between in-vehicle pollutants and percent of predicted FEV1 were observed, although higher PM2.5 was associated with lower FEV1 % predicted among participants with below-median asthma control (3 hours postcommute: −7.2 [95% CI = −11.8, −2.7]). Conclusions Level of asthma control may influence respiratory response to in-vehicle exposures experienced during rush-hour commuting. PMID:25901844

  1. Commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi.

    PubMed

    Kumar, Pramod; Gupta, N C

    2016-01-15

    A public health concern is to understand the linkages between specific pollution sources and adverse health impacts. Commuting can be viewed as one of the significant-exposure activity in high-vehicle density areas. This paper investigates the commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi, India. Air pollution levels are significantly contributed by automobile exhaust and also in-vehicle exposure can be higher sometime than ambient levels. Motorcycle, auto rickshaw, car and bus were selected to study particles concentration along two routes in Delhi between Kashmere Gate and Dwarka. The bus and auto rickshaw were running on compressed natural gas (CNG) while the car and motorcycle were operated on gasoline fuel. Aerosol spectrometer was employed to measure inhalable, thoracic and alveolic particles during morning and evening rush hours for five weekdays. From the study, we observed that the concentration levels of these particles were greatly influenced by transportation modes. Concentrations of inhalable particles were found higher during morning in auto rickshaw (332.81 ± 90.97 μg/m(3)) while the commuter of bus exhibited higher exposure of thoracic particles (292.23 ± 110.45 μg/m(3)) and car commuters were exposed to maximum concentrations of alveolic particles (222.37 ± 26.56 μg/m(3)). We observed that in evening car commuters experienced maximum concentrations of all sizes of particles among the four commuting modes. Interestingly, motorcycle commuters were exposed to lower levels of inhalable and thoracic particles during morning and evening hours as compared to other modes of transport. The mean values were found greater than the median values for all the modes of transport suggesting that positive skewed distributions are characteristics of naturally occurring phenomenon. PMID:26439646

  2. Electric-magnetic dualities in non-abelian and non-commutative gauge theories

    NASA Astrophysics Data System (ADS)

    Ho, Jun-Kai; Ma, Chen-Te

    2016-08-01

    Electric-magnetic dualities are equivalence between strong and weak coupling constants. A standard example is the exchange of electric and magnetic fields in an abelian gauge theory. We show three methods to perform electric-magnetic dualities in the case of the non-commutative U (1) gauge theory. The first method is to use covariant field strengths to be the electric and magnetic fields. We find an invariant form of an equation of motion after performing the electric-magnetic duality. The second method is to use the Seiberg-Witten map to rewrite the non-commutative U (1) gauge theory in terms of abelian field strength. The third method is to use the large Neveu Schwarz-Neveu Schwarz (NS-NS) background limit (non-commutativity parameter only has one degree of freedom) to consider the non-commutative U (1) gauge theory or D3-brane. In this limit, we introduce or dualize a new one-form gauge potential to get a D3-brane in a large Ramond-Ramond (R-R) background via field redefinition. We also use perturbation to study the equivalence between two D3-brane theories. Comparison of these methods in the non-commutative U (1) gauge theory gives different physical implications. The comparison reflects the differences between the non-abelian and non-commutative gauge theories in the electric-magnetic dualities. For a complete study, we also extend our studies to the simplest abelian and non-abelian p-form gauge theories, and a non-commutative theory with the non-abelian structure.

  3. Inhaled particle counts on bicycle commute routes of low and high proximity to motorised traffic

    NASA Astrophysics Data System (ADS)

    Cole-Hunter, Tom; Morawska, Lidia; Stewart, Ian; Jayaratne, Rohan; Solomon, Colin

    2012-12-01

    Frequent exposure to ultrafine particles (UFP) is associated with detrimental effects on cardiopulmonary function and health. UFP dose and therefore the associated health risk are a factor of exposure frequency, duration, and magnitude of (therefore also proximity to) a UFP emission source. Bicycle commuters using on-road routes during peak traffic times are sharing a microenvironment with high levels of motorised traffic, a major UFP emission source. Inhaled particle counts were measured on popular pre-identified bicycle commute route alterations of low (LOW) and high (HIGH) proximity to motorised traffic to the same inner-city destination at peak commute traffic times. During commute, real-time particle number concentration (PNC; mostly in the UFP range) and particle diameter (PD), heart rate, geographical location, and meteorological variables were measured. To determine inhaled particle counts, ventilation rate was calculated from heart-rate-ventilation associations, produced from periodic exercise testing. Total mean PNC of LOW, compared to HIGH, was reduced (1.56 × e4 ± 0.38 × e4 versus 3.06 × e4 ± 0.53 × e4 ppcc; p = 0.012). Total estimated ventilation rate did not differ significantly between LOW and HIGH (43 ± 5 versus 46 ± 9 L min-1; p = 0.136); however, due to total mean PNC, minute inhaled particle counts were 48% lower in LOW, compared to HIGH (6.71 × e8 ± 1.30 × e8 versus 14.08 × e8 ± 1.77 × e8 particles total; p = 0.003). For bicycle commuting at peak morning commute times, inhaled particle counts and therefore cardiopulmonary health risk may be substantially reduced by decreasing proximity to motorised traffic, which should be considered by both bicycle commuters and urban planners.

  4. Sandia bicycle commuters group -- pollution prevention at Sandia National Laboratories, New Mexico

    SciTech Connect

    Wrons, R.

    1998-06-01

    The Sandia Bicycle Commuters Group (SBCG) formed three years ago for the purpose of addressing issues that impact the bicycle commuting option. The meeting that launched the SBCG was scheduled in conjunction with National Bike-to-Work day in May 1995. Results from a survey handed out at the meeting solidly confirmed the issues and that an advocacy group was needed. The purpose statement for the Group headlines its web site and brochure: ``Existing to assist and educate the SNL workforce bicyclist on issues regarding Kirtland Air Force Base (KAFB) access, safety and bicycle-supporting facilities, in order to promote bicycling as an effective and enjoyable means of commuting.`` The SNL Pollution Prevention (P2) Team`s challenge to the SNL workforce is to ``prevent pollution, conserve natural resources, and save money``. In the first winter of its existence, the SBCG sponsored a winter commute contest in conjunction with the City`s Clean Air Campaign (CAC). The intent of the CAC is to promote alternative (to the single-occupant vehicle) commuting during the Winter Pollution Advisory Period (October 1--February 28), when the City runs the greatest risk of exceeding federal pollution limits.

  5. Bus commuters' coping strategies and anxiety from terrorism: an example of the Israeli experience.

    PubMed

    Gidron, Y; Gal, R; Zahavi, S

    1999-01-01

    This study examined the use of three coping strategies: (1) emotion-focused coping (calming-distraction); (2) problem-focused coping (checking-behavior); and (3) denial (reduced perceived vulnerability), and their relationship to anxiety from terrorism among 50 Israeli bus commuters. Their mean age was 31 years (60% females). Commuting frequency was negatively correlated, and problem-focused coping was positively correlated with anxiety from terrorism. Ratios of problem-focused coping/denial and of problem-focused/emotion-focused coping were each positively correlated with anxiety from terrorism. Coping ratios accounted for 15% of the variance in anxiety from terrorism, after considering commuting frequency. Combining minimal problem-focused preventative acts with distraction and reduced perceived vulnerability may be beneficial.

  6. Commutative n-ary superalgebras with an invariant skew-symmetric form

    NASA Astrophysics Data System (ADS)

    Vishnyakova, E. G.

    2015-12-01

    We study n-ary commutative superalgebras and L∞-algebras that possess a skew-symmetric invariant form, using the derived bracket formalism. This class of superalgebras includes for instance Lie algebras and their n-ary generalizations, commutative associative and Jordan algebras with an invariant form. We give a classification of anti-commutative m-dimensional (m - 3) -ary algebras with an invariant form, and a classification of real simple m-dimensional Lie (m - 3) -algebras with a positive definite invariant form up to isometry. Furthermore, we develop the Hodge Theory for L∞-algebras with a symmetric invariant form, and we describe quasi-Frobenius structures on skew-symmetric n-ary algebras.

  7. Ecological Analysis of Parking Prices and Active Commuting in US Cities, 2009.

    PubMed

    Whitfield, Geoffrey P; Wendel, Arthur M; Auchincloss, Amy H

    2016-01-01

    We conducted an ecological study to determine whether parking prices are associated with active commuting across US cities. We obtained parking prices for 107 US cities from the Drexel University Central Business District Public Parking Survey, obtained city prevalence of walking and bicycling to work from the American Community Survey, and used weighted least squares linear regression to explore associations between parking prices and active commuting. After adjusting for several covariates, walking to work was 3.1% higher for every additional dollar charged for off-street daily parking, but only among more densely populated cities, and no such association was detected for bicycling to work. These preliminary results hint at the potential for parking policies to influence commuting mode choice, a link that city planners and public health officials could consider when evaluating parking policies and active transportation behaviors. PMID:27609301

  8. The continuum phase diagram of the 2d non-commutative λϕ 4 model

    NASA Astrophysics Data System (ADS)

    Mejía-Díaz, Héctor; Bietenholz, Wolfgang; Panero, Marco

    2014-10-01

    We present a non-perturbative study of the λ ϕ 4 model on a non-commutative plane. The lattice regularised form can be mapped onto a Hermitian matrix model, which enables Monte Carlo simulations. Numerical data reveal the phase diagram; at large λ it contains a "striped phase", which is absent in the commutative case. We explore the question whether or not this phenomenon persists in a Double Scaling Limit (DSL), which extrapolates simultaneously to the continuum and to infinite volume, at a fixed non-commutativity parameter. To this end, we introduce a dimensional lattice spacing based on the decay of the correlation function. Our results provide evidence for the existence of a striped phase even in the DSL, which implies the spontaneous breaking of translation symmetry. Due to the non-locality of this model, this does not contradict the Mermin-Wagner theorem.

  9. Suicides in commuting railway systems: The case of Stockholm county, Sweden.

    PubMed

    Ceccato, Vania; Uittenbogaard, Adriaan

    2016-07-01

    The objective of this study is to understand the spatial and temporal dynamics of suicides in commuting railway environments. Data on suicides in Stockholm commuting railway from 2006 to 2013 was analysed. The study sets out to identify significant clusters in suicides then evaluate whether commuting railway environments affect variations in suicide rates. Fieldwork inspection, spatial cluster techniques (NNHC and Getis-Ord statistics) and regression models underlie the methodology of study. Findings show no seasonality was observed in suicide cases, but winter months concentrate a larger share of events. Suicides do not occur evenly throughout the day but tend to take place more often in weekdays. Modelling findings shows that suicide rates increase with speed trains and decrease where barriers along tracks are installed. Although high speed trains are still a motive of concern for suicide prevention, findings call for a whole railway-approach to safety - one that extends maintenance beyond the platforms and stations' vicinities.

  10. Ecological Analysis of Parking Prices and Active Commuting in US Cities, 2009

    PubMed Central

    Wendel, Arthur M.; Auchincloss, Amy H.

    2016-01-01

    We conducted an ecological study to determine whether parking prices are associated with active commuting across US cities. We obtained parking prices for 107 US cities from the Drexel University Central Business District Public Parking Survey, obtained city prevalence of walking and bicycling to work from the American Community Survey, and used weighted least squares linear regression to explore associations between parking prices and active commuting. After adjusting for several covariates, walking to work was 3.1% higher for every additional dollar charged for off-street daily parking, but only among more densely populated cities, and no such association was detected for bicycling to work. These preliminary results hint at the potential for parking policies to influence commuting mode choice, a link that city planners and public health officials could consider when evaluating parking policies and active transportation behaviors. PMID:27609301

  11. Relativistic spectrum of hydrogen atom in the space-time non-commutativity

    SciTech Connect

    Moumni, Mustafa; BenSlama, Achour; Zaim, Slimane

    2012-06-27

    We study space-time non-commutativity applied to the hydrogen atom and its phenomenological effects. We find that it modifies the Coulomb potential in the Hamiltonian and add an r{sup -3} part. By calculating the energies from Dirac equation using perturbation theory, we study the modifications to the hydrogen spectrum. We find that it removes the degeneracy with respect to the total angular momentum quantum number and acts like a Lamb shift. Comparing the results with experimental values from spectroscopy, we get a new bound for the space-time non-commutative parameter.

  12. Radiative corrections to the non commutative photon propagator at one-loop order

    SciTech Connect

    Boutalbi, E.; Kouadik, S.

    2012-06-27

    We study the non-commutative gauge theory on the Moyal space. We add the harmonic potential introduced by Grosse and Wulkenhaar to the Maxwell Lagrange as well as the Gauge fixation. We determine the non-commutative U{sub *}(1) Gauge action which is invariant under the BRST transformations in the matrix basis. We determine in this basis the quadratic parts and the vertex of the Gauge field A{sub {mu}} and of the Faddeev-Popov ghost fields c(bar sign)andc. Finally, we study the perturbative correction to one loop order of the one point function in the matrix basis.

  13. Wigner function for Klein-Gordon oscillator in commutative and noncommutative spaces

    NASA Astrophysics Data System (ADS)

    Hassanabadi, S.; Ghominejad, M.

    2016-06-01

    As a quasi-probability distribution function in phase-space and a special representation of the density matrix, the Wigner function is of great significance in physics. In this work, the Wigner function for the Klein-Gordon oscillator is studied in commutative and noncommutative spaces. We first study the Wigner function for Klein-Gordon oscillator in commutative space then, by using a generalized Bopp's shift method, we obtain the corresponding Wigner function in noncommutative space. The additional terms in Wigner function on a NC space is related to the noncommutativity of space.

  14. Comparison, contrast, and critique of four commuter coordination systems. Final report

    SciTech Connect

    Margulies, N.; Baker, J.

    1990-02-01

    The review establishes a general understanding of the concept of organizational effectiveness by summarizing major models of effectiveness presented in literature, and specifies a useful framework for analyzing organizational effectiveness in the 4 commuter coordination systems documented in the report. A model of interorganizational relationships was developed as a result of the interviews and was employed to evaluate the strengths and weaknesses of each organizational form and to generate an ideal type for future rideshare organizations. Legislation legitimizing the commuter coordination service was found to be a critical factor in the ability of the agencies to impact their environments.

  15. A new inverter topology using GTO commutation. [Gate Turn Off thyristor

    NASA Technical Reports Server (NTRS)

    Rippel, W. E.

    1983-01-01

    A new N-phase, forced commutated bridge inverter topology has been developed wherein a single Gate Turn Off Thyristor (GTO) is used to commutate each of 2N main Thyristors (SCRs). Since, for most applications, the primary loss mechanism is the SCR forward drop, very high efficiencies are possible. Compared with conventional pure SCR and pure GTO inverters, cost per kW is lower - in the former case due to the large cost differential between GTOs and SCRs. Other advantages of the new inverter include high power density, low switching losses and stresses, modulation flexibility and amenability to high voltage and high frequency operation.

  16. 49 CFR 37.42 - Service in an integrated setting to passengers at intercity, commuter, and high-speed rail...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... CFR 38.95(c) and 38.125(c). Effective Date Note: At 76 FR 57935, Sept. 19, 2011, § 37.42 was added... intercity, commuter, and high-speed rail station platforms constructed or altered after February 1, 2012. 37... passengers at intercity, commuter, and high-speed rail station platforms constructed or altered...

  17. 49 CFR 37.42 - Service in an Integrated Setting to Passengers at Intercity, Commuter, and High-Speed Rail...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... CFR 38.95(c) and 38.125(c). ... Intercity, Commuter, and High-Speed Rail Station Platforms Constructed or Altered After February 1, 2012. 37... Passengers at Intercity, Commuter, and High-Speed Rail Station Platforms Constructed or Altered...

  18. 49 CFR 37.42 - Service in an Integrated Setting to Passengers at Intercity, Commuter, and High-Speed Rail...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CFR 38.95(c) and 38.125(c). ... Intercity, Commuter, and High-Speed Rail Station Platforms Constructed or Altered After February 1, 2012. 37... Passengers at Intercity, Commuter, and High-Speed Rail Station Platforms Constructed or Altered...

  19. 49 CFR 37.42 - Service in an Integrated Setting to Passengers at Intercity, Commuter, and High-Speed Rail...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CFR 38.95(c) and 38.125(c). ... Intercity, Commuter, and High-Speed Rail Station Platforms Constructed or Altered After February 1, 2012. 37... Passengers at Intercity, Commuter, and High-Speed Rail Station Platforms Constructed or Altered...

  20. Environmental justice in the context of commuters' exposure to CO and PM10 in Bangalore, India.

    PubMed

    Sabapathy, Ashwin; Saksena, Sumeet; Flachsbart, Peter

    2015-01-01

    The Information Technology (IT) industry in the globalizing city of Bangalore has transformed the socio-economic characteristics of the city. The intent of this study, developed from an environmental justice framework, was to determine whether air pollutant exposure while commuting to and from work is related to a commuter's income characteristics and whether differences are larger for the IT economy when compared with a traditional manufacturing-oriented economy of the city. The study measured exposures to CO and PM10 using personal samplers for a sample of employees of a traditional public sector manufacturing industry (n=20) and an IT industry (n=26). This approach overcomes the methodological limitations of previous environmental justice studies. Socio-economic characteristics were obtained from a questionnaire-based survey of 436 employees in two firms. The results do not support the environmental justice hypothesis for commuting in Bangalore mainly because longer commuting times of higher-income groups offsets the benefits of lower pollutant concentrations. The study nevertheless demonstrates the use of personal exposure for environmental justice assessments.

  1. Fermionic Tunneling Effect and Hawking Radiation in a Non Commutative FRW Universe

    SciTech Connect

    Bouhalouf, H.; Aissaoui, H.; Mebarki, N.

    2010-10-31

    The formalism of a non commutative gauge gravity is applied to an FRW universe and the corresponding modified metric, veirbein and spin connection components are obtained. Moreover, using the Hamilton-Jacobi method and as a pure space-time deformation effect, the NCG Hawking radiation via a fermionic tunneling transition through the dynamical NCG horizon is also studied.

  2. 14 CFR 23.574 - Metallic damage tolerance and fatigue evaluation of commuter category airplanes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Metallic damage tolerance and fatigue evaluation of commuter category airplanes. 23.574 Section 23.574 Aeronautics and Space FEDERAL AVIATION..., corrosion, defects, or damage will be avoided throughout the operational life of the airplane....

  3. 14 CFR 23.574 - Metallic damage tolerance and fatigue evaluation of commuter category airplanes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Metallic damage tolerance and fatigue evaluation of commuter category airplanes. 23.574 Section 23.574 Aeronautics and Space FEDERAL AVIATION..., corrosion, defects, or damage will be avoided throughout the operational life of the airplane....

  4. The Relationship Between Self-Concept and Marital Adjustment for Commuter College Students

    ERIC Educational Resources Information Center

    Hall, William M.; Valine, Warren J.

    1977-01-01

    An investigation was made of the relationship between self-concept and the adjustment of commuter college students. Instruments used were the Tennessee Self Concept Scale and the Locke-Wallace Marital Adjustment Test. There was a significant relationship between self-concept and marital adjustment. (Author)

  5. Undergraduate Research and Metropolitan Commuter University Student Involvement: Exploring the Narratives of Five Female Undergraduate Students

    ERIC Educational Resources Information Center

    Kwong Caputo, Jolina Jade

    2013-01-01

    This study sought to explore the lived experiences of five female, first-generation, low-income students who attend a metropolitan commuter university, and investigate how a structured undergraduate research experience exerts influence on the women's academic and social involvement. A qualitative case study with a narrative and grounded…

  6. Who Needs to Do What Where?: Using Learning Management Systems on Residential vs. Commuter Campuses

    ERIC Educational Resources Information Center

    Lonn, Steven; Teasley, Stephanie D.; Krumm, Andrew E.

    2011-01-01

    Learning Management Systems (LMS) are web-based systems allowing instructors and/or students to share materials and interact online. This study compared differences in LMS use between instructors and students at a large residential campus with students at a smaller commuter campus. Responses to an online survey about LMS activities and tools were…

  7. 32 CFR Appendix B to Part 110 - Formula For ROTC Commutation Rates

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 1 2013-07-01 2013-07-01 false Formula For ROTC Commutation Rates B Appendix B to Part 110 National Defense Department of Defense OFFICE OF THE SECRETARY OF DEFENSE PERSONNEL... MEMBERS OF THE SENIOR RESERVE OFFICERS' TRAINING CORPS Pt. 110, App. B Appendix B to Part 110—Formula...

  8. A geography of moral hazard: sources and sinks of motor-vehicle commuting externalities.

    PubMed

    Yiannakoulias, Niko; Bland, Widmer; Scott, Darren M

    2014-09-01

    Motor-vehicles are responsible for harms to health that are not directly experienced by individual drivers - such as air pollution and risk of injury to pedestrians. In addition to their direct effects on health, these harms also represent a moral hazard since drivers are not required to consider their effects as part of their decision to drive. We describe an approach for estimating sources of motor-vehicle commuter externalities as a means of understanding the geography of moral hazard, and in particular, the spatial displacement of negative health externalities associated with motor-vehicle commuting. This approach models motor-vehicle commuter traffic flow by trip origin for small geographic areas within the City of Toronto, Ontario. We find that most health-related externalities associated with motor-vehicle commuters are not locally generated, with a large share coming from outside Toronto. Low income is associated with externalities originating outside the municipal boundary, but not with locally sourced externalities. We discuss the impact of geographical moral hazard on the agency of citizens as well as policy options aimed at addressing motor-vehicle externalities.

  9. Tertiary Student Attitudes to Bicycle Commuting in a Regional Australian University

    ERIC Educational Resources Information Center

    Whannell, Patricia; Whannell, Robert; White, Richard

    2012-01-01

    Purpose: The purpose of this paper is to provide executive management at a regional university with empirical data to justify, or otherwise, a substantial outlay of funds to support bicycle commuting as a viable strategy for the reduction of traffic congestion. Design/methodology/approach: A custom designed questionnaire was completed by 270…

  10. Technology's Role in Learning at a Commuter Campus: The Student Perspective

    ERIC Educational Resources Information Center

    Buckenmeyer, Janet A.; Barczyk, Casimir; Hixon, Emily; Zamojski, Heather; Tomory, Annette

    2016-01-01

    Patterns of technology ownership and usage, as well as skills with and preferences for various technologies, affect the college experience (Educause 2012). Students at a commuter campus of a large Midwestern public university were surveyed about technology and the learning process: 94% of the respondents believed that technology had the potential…

  11. 77 FR 45715 - Application of Key Lime Air Corporation for Commuter Authority

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Key Lime Air Corporation for Commuter Authority AGENCY: Department... not issue an order finding Key Lime Air Corporation fit, willing, and able, and awarding it a...

  12. The "Reverse Commute": Adult Students and the Transition from Professional to Academic Literacy

    ERIC Educational Resources Information Center

    Michaud, Michael J.

    2011-01-01

    The notion of "transporting literacy" across spheres or cultures is a useful way to imagine the transition many of today's adult students make as writers from the literate sphere of the workplace to that of the school--a transition the author refers to in this article as the "reverse commute." By the time such students reach (or rereach) the…

  13. Implementation problem for the canonical commutation relation in terms of quantum white noise derivatives

    SciTech Connect

    Ji, Un Cig; Obata, Nobuaki

    2010-12-15

    The implementation problem for the canonical commutation relation is reduced to a system of differential equations for Fock space operators containing new type of derivatives. We solve these differential equations systematically by means of quantum white noise calculus, and obtain the solution to the implementation problem.

  14. Environmental justice in the context of commuters' exposure to CO and PM10 in Bangalore, India.

    PubMed

    Sabapathy, Ashwin; Saksena, Sumeet; Flachsbart, Peter

    2015-01-01

    The Information Technology (IT) industry in the globalizing city of Bangalore has transformed the socio-economic characteristics of the city. The intent of this study, developed from an environmental justice framework, was to determine whether air pollutant exposure while commuting to and from work is related to a commuter's income characteristics and whether differences are larger for the IT economy when compared with a traditional manufacturing-oriented economy of the city. The study measured exposures to CO and PM10 using personal samplers for a sample of employees of a traditional public sector manufacturing industry (n=20) and an IT industry (n=26). This approach overcomes the methodological limitations of previous environmental justice studies. Socio-economic characteristics were obtained from a questionnaire-based survey of 436 employees in two firms. The results do not support the environmental justice hypothesis for commuting in Bangalore mainly because longer commuting times of higher-income groups offsets the benefits of lower pollutant concentrations. The study nevertheless demonstrates the use of personal exposure for environmental justice assessments. PMID:24849797

  15. 77 FR 43416 - Application of Star Marianas Air, Inc. for Commuter Authority

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-24

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Star Marianas Air, Inc. for Commuter Authority AGENCY: Department... tentatively finding Star Marianas Air, Inc., fit, willing, and able to provide scheduled passenger service...

  16. 75 FR 69734 - Application of Island Airlines, LLC for Commuter Air Carrier Authorization

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Island Airlines, LLC for Commuter Air Carrier Authorization AGENCY... it should not issue an order finding Island Airlines, LLC, fit, willing, and able, and awarding...

  17. Probability distribution of the index in gauge theory on 2d non-commutative geometry

    NASA Astrophysics Data System (ADS)

    Aoki, Hajime; Nishimura, Jun; Susaki, Yoshiaki

    2007-10-01

    We investigate the effects of non-commutative geometry on the topological aspects of gauge theory using a non-perturbative formulation based on the twisted reduced model. The configuration space is decomposed into topological sectors labeled by the index ν of the overlap Dirac operator satisfying the Ginsparg-Wilson relation. We study the probability distribution of ν by Monte Carlo simulation of the U(1) gauge theory on 2d non-commutative space with periodic boundary conditions. In general the distribution is asymmetric under ν mapsto -ν, reflecting the parity violation due to non-commutative geometry. In the continuum and infinite-volume limits, however, the distribution turns out to be dominated by the topologically trivial sector. This conclusion is consistent with the instanton calculus in the continuum theory. However, it is in striking contrast to the known results in the commutative case obtained from lattice simulation, where the distribution is Gaussian in a finite volume, but the width diverges in the infinite-volume limit. We also calculate the average action in each topological sector, and provide deeper understanding of the observed phenomenon.

  18. 49 CFR 37.87 - Purchase or lease of used intercity and commuter rail cars.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Purchase or lease of used intercity and commuter rail cars. 37.87 Section 37.87 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Acquisition of Accessible Vehicles By Public Entities §...

  19. 49 CFR 37.85 - Purchase or lease of new intercity and commuter rail cars.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Purchase or lease of new intercity and commuter rail cars. 37.85 Section 37.85 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Acquisition of Accessible Vehicles By Public Entities §...

  20. 40 CFR 52.1161 - Incentives for reduction in single-passenger commuter vehicle use.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Incentives for reduction in single-passenger commuter vehicle use. 52.1161 Section 52.1161 Protection of Environment ENVIRONMENTAL PROTECTION... live at the educational institution and who travels to and from classes by any mode of travel....

  1. Merchant Marine and Commuter Families: A Comparison of Couples Who Live Apart.

    ERIC Educational Resources Information Center

    Gross, Harriet Engel; And Others

    A study compared commuter and Merchant Marine families with traditional households in order to separate effects related to living apart from those related to the career status (single vs. dual) of families. During the study researchers conducted in-depth interviews with 50 wives and 30 husbands representing 58 Merchant Marine families of whom 22…

  2. 14 CFR 23.574 - Metallic damage tolerance and fatigue evaluation of commuter category airplanes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Metallic damage tolerance and fatigue... COMMUTER CATEGORY AIRPLANES Structure Fatigue Evaluation § 23.574 Metallic damage tolerance and fatigue... evaluation of the strength, detail design, and fabrication must show that catastrophic failure due to...

  3. "I Am More Productive in the Library Because It's Quiet": Commuter Students in the College Library

    ERIC Educational Resources Information Center

    Regalado, Mariana; Smale, Maura A.

    2015-01-01

    This article discusses commuter students' experiences with the academic library, drawn from a qualitative study at the City University of New York. Undergraduates at six community and baccalaureate colleges were interviewed to explore how they fit schoolwork into their days, and the challenges and opportunities they encountered. Students…

  4. A Study of Commuting Costs at Seven Illinois Public Community Colleges.

    ERIC Educational Resources Information Center

    Illinois Community Coll. Board, Springfield.

    In 1981, a study of the costs to students of commuting to community colleges in Illinois was conducted as an aid to analyzing student financial need policies, to helping students make informed decisions about college attendance, and to analyzing tuition policies related to student costs. A survey instrument was administered to 2,847 students from…

  5. Parent, psycho-social, and household factors associated with children's active commuting to school

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Active commuting to school (ACS), i.e. walking or cycling to school, has been associated with higher levels of physical activity. Few studies have examined children's ACS using the framework of behavior change theory. This study used social cognitive theory as the framework. To examine the relations...

  6. Parent, psycho-social, and household factors associated with urban children's active commuting to school

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Active commuting to school (ACS), i.e. walking or cycling to school, has been proposed as a method to increase physical activity. Few studies have examined children's ACS using the framework of behavior change theory. This study used social cognitive theory as the framework. The objective of this st...

  7. 49 CFR 37.87 - Purchase or lease of used intercity and commuter rail cars.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... rail cars. 37.87 Section 37.87 Transportation Office of the Secretary of Transportation TRANSPORTATION....87 Purchase or lease of used intercity and commuter rail cars. (a) Except as provided elsewhere in... car after August 25, 1990, shall ensure that the car is readily accessible to and usable...

  8. 75 FR 13332 - Application of Charter Air Transport, Inc. for Commuter Authority

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Charter Air Transport, Inc. for Commuter Authority Correction In notice document 2010-5555 appearing on page 12328 in the issue of Monday, March 15, 2010, make...

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

    NASA Astrophysics Data System (ADS)

    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.

  10. 14 CFR 21.183 - Issue of standard airworthiness certificates for normal, utility, acrobatic, commuter, and...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... complied with. (2) For normal, utility, acrobatic, commuter, or transport category propeller driven small... materials to which § 36.1583 of this chapter does not apply) that have not had any flight time before the... affecting § 21.183, see the List of CFR Sections Affected, which appears in the Finding Aids section of...

  11. 14 CFR 21.183 - Issue of standard airworthiness certificates for normal, utility, acrobatic, commuter, and...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... complied with. (2) For normal, utility, acrobatic, commuter, or transport category propeller driven small... materials to which § 36.1583 of this chapter does not apply) that have not had any flight time before the... affecting § 21.183, see the List of CFR Sections Affected, which appears in the Finding Aids section of...

  12. 14 CFR 21.183 - Issue of standard airworthiness certificates for normal, utility, acrobatic, commuter, and...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., utility, acrobatic, commuter, or transport category propeller driven small airplanes (except for those..., as effective on January 1, 1966) or for dispensing fire fighting materials to which § 36.1583 of this... § 21.183, see the List of CFR Sections Affected, which appears in the Finding Aids section of...

  13. 14 CFR 21.183 - Issue of standard airworthiness certificates for normal, utility, acrobatic, commuter, and...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... complied with. (2) For normal, utility, acrobatic, commuter, or transport category propeller driven small... materials to which § 36.1583 of this chapter does not apply) that have not had any flight time before the... affecting § 21.183, see the List of CFR Sections Affected, which appears in the Finding Aids section of...

  14. 14 CFR 21.183 - Issue of standard airworthiness certificates for normal, utility, acrobatic, commuter, and...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., utility, acrobatic, commuter, or transport category propeller driven small airplanes (except for those..., as effective on January 1, 1966) or for dispensing fire fighting materials to which § 36.1583 of this... § 21.183, see the List of CFR Sections Affected, which appears in the Finding Aids section of...

  15. Understanding Commuter Student Self-Efficacy for Leadership: A Within-Group Analysis

    ERIC Educational Resources Information Center

    Dugan, John P.; Garland, John L.; Jacoby, Barbara; Gasiorski, Anna

    2008-01-01

    Although students who live off-campus comprise over 85% of today's college enrollments (Horn & Nevill, 2006), the body of research on this group is far smaller than that on residential students. Researchers regularly treat commuter students as a homogenous group and largely ignore the significant within-group differences that characterize the…

  16. Differences in Work, Levels of Involvement, and Academic Performance between Residential and Commuter Students

    ERIC Educational Resources Information Center

    Alfano, Halley J.; Eduljee, Nina B.

    2013-01-01

    The purpose of this study was to investigate the relationship between work, levels of involvement and academic performance between residential and commuter students. One hundred and eight undergraduate students at a private college in the Northeast were surveyed. Surveys aimed at examining work and levels of involvement were administered to the…

  17. Predictors of children's active commuting to school: An observational evaluation in 5 U.S. communities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Few reports examined long term predictors of children's active commuting to school (walking or cycling to school, ACS). The purpose of this study was to identify predictors of ACS over 1 school year among a sample of children with relatively high rates of ACS. Parents were surveyed in September 201...

  18. Fermionic Tunneling Effect and Hawking Radiation in a Non Commutative FRW Universe

    NASA Astrophysics Data System (ADS)

    Bouhalouf, H.; Mebarki, N.; Aissaoui, H.

    2010-10-01

    The formalism of a non commutative gauge gravity is applied to an FRW universe and the corresponding modified metric, veirbein and spin connection components are obtained. Moreover, using the Hamilton-Jacobi method and as a pure space-time deformation effect, the NCG Hawking radiation via a fermionic tunneling transition through the dynamical NCG horizon is also studied.

  19. 78 FR 72746 - Application of Corporate Flight Management, Inc., for Commuter Authority

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Corporate Flight Management, Inc., for Commuter Authority AGENCY... why it should not issue an order finding Corporate Flight Management, Inc., fit, willing, and...

  20. An Analysis of the Relationship between Distance from Campus and GPA of Commuter Students

    ERIC Educational Resources Information Center

    Nelson, Danielle; Misra, Kaustav; Sype, Gail E.; Mackie, Wayne

    2016-01-01

    A variety of factors influence a student's ability to succeed in college and complete a degree program. Students who live on-campus, at least during their freshman year, have been shown to be more likely to complete their degrees than are students who live off-campus. Students who are commuters may have more demands on their time and may have…

  1. Reorganization of Elementary Educational System and Commutation of Children to Collective Commune Schools.

    ERIC Educational Resources Information Center

    Palonka, Krystyna Maria

    Between 1973-1979, the elementary educational system in rural areas of Poland has been reorganized into a system of collective commune schools; students commute or are bused to the schools. Since September 1973, 944 new collective commune schools have been set up. A study of the data indicates that the process of setting up collective commune…

  2. Active and Passive Commuting to School: Influences on Affect in Primary School Children

    ERIC Educational Resources Information Center

    Hulley, Angela; Bentley, Nick; Clough, Catherine; Fishlock, Adelle; Morrell, Frances; O'Brien, James; Radmore, Joseph

    2008-01-01

    Active commuting among school children is being encouraged for physical and environmental reasons, but little is known about its influence on affect. The aim of this study was to test the hypothesis that children who walk further to school experience increased arousal and affective valence compared with children who walk a short distance. This was…

  3. Picturing commuting: photovoice and seeking well-being in everyday travel

    PubMed Central

    Ogilvie, David

    2015-01-01

    We used participant-produced photography to investigate everyday commuting practices in Cambridge, UK. Photovoice served as an observational method for producing ethnographically rich data. A total of 19 participants produced over 500 photos about their journeys to and from work and took part in photo-elicitation interviews. Three themes emerged. First, many images depicted ‘well-being’ in commuting, for example, beautiful landscapes. Second, during elicitation interviews, participants described positive images that they intended but failed to capture in photos. Third, those participants who did not depict well-being described a lack of choice in their commuting, while those who acknowledged well-being seemed to do so in order to make practices of commuting meaningful and habitable. While our interpretations of photos of well-being could be subject to a methodological fallacy relating to a preference for positive over negative images in lay photography, we nonetheless suggest that the rich visual and oral narratives indicate a ‘real’ experience, albeit elicited through the photovoice. PMID:25972763

  4. 76 FR 81790 - Airworthiness Standards: Normal, Utility, Acrobatic, and Commuter Category Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... From the Federal Register Online via the Government Publishing Office FEDERAL AVIATION ADMINISTRATION 14 CFR Part 23 Airworthiness Standards: Normal, Utility, Acrobatic, and Commuter Category Airplanes CFR Correction In Title 14 of the Code of Federal Regulations, Parts 1 to 59, revised as...

  5. Kindergartners' Understanding of Additive Commutativity within the Context of Word Problems.

    ERIC Educational Resources Information Center

    Wilkins, Jesse L. M.; Baroody, Arthur J.; Tiilikainen, Sirpa

    2001-01-01

    Investigated kindergartners' unary and binary understanding of additive commutativity using performance on tasks involving change-add-to and part-part-whole word problems, respectively. Found that data were inconsistent with models put forth by Baroody and Gannon and by Resnick and suggest three alternate theoretical explanations. Success on tasks…

  6. Succeeding in the City: Challenges and Best Practices on Urban Commuter Campuses

    ERIC Educational Resources Information Center

    Clark, Marcia Roe

    2006-01-01

    The work of helping students succeed on urban commuter campuses may be some of the most complicated in higher education. Even in understanding their tasks, educators at city-based institutions must typically draw on research and practice from an amalgam of other types of institutions, including community colleges, metropolitan universities, urban…

  7. Exploring bikeability in a metropolitan setting: stimulating and hindering factors in commuting route environments

    PubMed Central

    2012-01-01

    Background Route environments may influence people's active commuting positively and thereby contribute to public health. Assessments of route environments are, however, needed in order to better understand the possible relationship between active commuting and the route environment. The aim of this study was, therefore, to assess the potential associations between perceptions of whether the route environment on the whole hinders or stimulates bicycle commuting and perceptions of environmental factors. Methods The Active Commuting Route Environment Scale (ACRES) was used for the assessment of bicycle commuters' perceptions of their route environments in the inner urban parts of Greater Stockholm, Sweden. Bicycle commuters (n = 827) were recruited by advertisements in newspapers. Simultaneous multiple regression analyses were used to assess the relation between predictor variables (such as levels of exhaust fumes, noise, traffic speed, traffic congestion and greenery) and the outcome variable (hindering - stimulating route environments). Two models were run, (Model 1) without and (Model 2) with the item traffic: unsafe or safe included as a predictor. Results Overall, about 40% of the variance of hindering - stimulating route environments was explained by the environmental predictors in our models (Model 1, R2 = 0.415, and Model 2, R 2= 0.435). The regression equation for Model 1 was: y = 8.53 + 0.33 ugly or beautiful + 0.14 greenery + (-0.14) course of the route + (-0.13) exhaust fumes + (-0.09) congestion: all types of vehicles (p ≤ 0.019). The regression equation for Model 2 was y = 6.55 + 0.31 ugly or beautiful + 0.16 traffic: unsafe or safe + (-0.13) exhaust fumes + 0.12 greenery + (-0.12) course of the route (p ≤ 0.001). Conclusions The main results indicate that beautiful, green and safe route environments seem to be, independently of each other, stimulating factors for bicycle commuting in inner urban areas. On the other hand, exhaust fumes, traffic

  8. NYPA/TH!NK Clean Commute Program Report – Inception through February 2003

    SciTech Connect

    Don Karner; James Francfort

    2003-07-01

    The Clean Commute Program uses TH!NK city electric vehicles from Ford Motor Company’s electric vehicle group, TH!NK Mobility, to demonstrate the feasibility of using electric transportation in urban applications. The primary Program partners are the New York Power Authority (NYPA) and Ford. The other Program partners providing funding and other support include the Metropolitan Transportation Authority, Metro North Railroad, Long Island Railroad, New York State Energy Research and Development Authority, Long Island Power Authority, New York State Department of Transportation, New York City Department of Transportation, and the U.S. Department of Energy’s Advanced Vehicle Testing Activity (AVTA). The data in this report is being collected via an internet-based questionnaire system by the AVTA through its subcontractor Electric Transportation Applications. Suburban New York City railroad commuters use the TH!NK city vehicles to commute from their private residences to railroad stations where they catch commuter trains into New York City. Electric vehicle charging infrastructure for the TH!NK cities is located at the commuters’ private residences as well as seven train stations. Eighty-seven commuters are using the TH!NK city vehicles, with 80% actively providing data to the AVTA. The participants have driven the vehicles nearly 150,000 miles since Program inception, avoiding the use of almost 7,000 gallons of gasoline. The TH!NK city vehicles are driven an average of between 180 and 230 miles per month, and over 95% of all trips taken with the TH!NK city vehicles replace trips previously taken in gasoline vehicles. This report covers the period from Program inception through February 2003.

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

    PubMed Central

    Good, Nicholas; Mölter, 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; Volckens, John

    2016-01-01

    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 (PM2.5)) during commutes between the home and workplace for 45 participants. Participants completed 8 days of commuting by car and bicycle on direct and alternative (reduced traffic) routes. Mean within-person exposures to BC, PM2.5, and PNC were higher when commuting by cycling than when driving, but mean CO exposure was lower when cycling. Exposures to CO and BC were reduced when commuting along alternative routes. When cumulative exposure was considered, the benefits from cycling were attenuated, in the case of CO, or exacerbated, in the case of particulate exposures, owing to the increased duration of the commute. Although choice of route can reduce mean exposure, the effect of route length and duration often offsets these reductions when cumulative exposure is considered. Furthermore, increased ventilation rate when cycling may result in a more harmful dose than inhalation at a lower ventilation rate. PMID:26507004

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

    PubMed

    Good, Nicholas; Mölter, 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; Volckens, John

    2016-06-01

    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 (PM2.5)) during commutes between the home and workplace for 45 participants. Participants completed 8 days of commuting by car and bicycle on direct and alternative (reduced traffic) routes. Mean within-person exposures to BC, PM2.5, and PNC were higher when commuting by cycling than when driving, but mean CO exposure was lower when cycling. Exposures to CO and BC were reduced when commuting along alternative routes. When cumulative exposure was considered, the benefits from cycling were attenuated, in the case of CO, or exacerbated, in the case of particulate exposures, owing to the increased duration of the commute. Although choice of route can reduce mean exposure, the effect of route length and duration often offsets these reductions when cumulative exposure is considered. Furthermore, increased ventilation rate when cycling may result in a more harmful dose than inhalation at a lower ventilation rate. PMID:26507004

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

    PubMed

    Good, Nicholas; Mölter, 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; Volckens, John

    2016-06-01

    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 (PM2.5)) during commutes between the home and workplace for 45 participants. Participants completed 8 days of commuting by car and bicycle on direct and alternative (reduced traffic) routes. Mean within-person exposures to BC, PM2.5, and PNC were higher when commuting by cycling than when driving, but mean CO exposure was lower when cycling. Exposures to CO and BC were reduced when commuting along alternative routes. When cumulative exposure was considered, the benefits from cycling were attenuated, in the case of CO, or exacerbated, in the case of particulate exposures, owing to the increased duration of the commute. Although choice of route can reduce mean exposure, the effect of route length and duration often offsets these reductions when cumulative exposure is considered. Furthermore, increased ventilation rate when cycling may result in a more harmful dose than inhalation at a lower ventilation rate.

  12. The relevance of commuter and work/school exposure in an epidemiological study on traffic-related air pollution.

    PubMed

    Ragettli, Martina S; Phuleria, Harish C; Tsai, Ming-Yi; Schindler, Christian; de Nazelle, Audrey; Ducret-Stich, Regina E; Ineichen, Alex; Perez, Laura; Braun-Fahrländer, Charlotte; Probst-Hensch, Nicole; Künzli, Nino

    2015-01-01

    Exposure during transport and at non-residential locations is ignored in most epidemiological studies of traffic-related air pollution. We investigated the impact of separately estimating NO2 long-term outdoor exposures at home, work/school, and while commuting on the association between this marker of exposure and potential health outcomes. We used spatially and temporally resolved commuter route data and model-based NO2 estimates of a population sample in Basel, Switzerland, to assign individual NO2-exposure estimates of increasing complexity, namely (1) home outdoor concentration; (2) time-weighted home and work/school concentrations; and (3) time-weighted concentration incorporating home, work/school and commute. On the basis of their covariance structure, we estimated the expectable relative differences in the regression slopes between a quantitative health outcome and our measures of individual NO2 exposure using a standard measurement error model. The traditional use of home outdoor NO2 alone indicated a 12% (95% CI: 11-14%) underestimation of related health effects as compared with integrating both home and work/school outdoor concentrations. Mean contribution of commuting to total weekly exposure was small (3.2%; range 0.1-13.5%). Thus, ignoring commute in the total population may not significantly underestimate health effects as compared with the model combining home and work/school. For individuals commuting between Basel-City and Basel-Country, ignoring commute may produce, however, a significant attenuation bias of 4% (95% CI: 4-5%). Our results illustrate the importance of including work/school locations in assessments of long-term exposures to traffic-related air pollutants such as NO2. Information on individuals' commuting behavior may further improve exposure estimates, especially for subjects having lengthy commutes along major transportation routes.

  13. Associations between Recreational and Commuter Cycling, Changes in Cycling, and Type 2 Diabetes Risk: A Cohort Study of Danish Men and Women

    PubMed Central

    Rasmussen, Martin G.; Grøntved, Anders; Blond, Kim; Overvad, Kim; Tjønneland, Anne; Jensen, Majken K.; Østergaard, Lars

    2016-01-01

    second examination, respectively. Lastly, in the analysis of commuter cycling, multivariable HRs (95% CI) were 1, 0.72 (0.60, 0.87), 0.83 (0.69, 1.00), and 0.70 (0.57, 0.85) (p for trend = <0.001) for cycling 0, 1–60, 61–150, and >150 min/wk to work, respectively. The main limitation of the current study is the use of self-reported physical activity. Conclusions Commuter and recreational cycling was consistently associated with lower risk of T2D in Danish adults. Our results also provide evidence that late-in-life initiation of or continued engagement in cycling lowers risk of T2D. PMID:27403867

  14. Commutability of the CRM 470 C-reactive protein value in the Dade Behring N High Sensitivity CRP assay.

    PubMed

    Johnson, A Myron; Ledue, Thomas B; Collins, Marilyn F

    2003-02-01

    Certified Reference Material 470 (CRM 470) demonstrates commutability with both the manufacturer's calibrator and with dilutions of serum pools in the Dade Behring N High Sensitivity assay for C-reactive protein (CRP). Both regression and back calibration show similar nonlinearity for all materials, largely due to the method of calibration curve fitting used in this assay. Significant differences in values among the currently available commercial assays can be largely overcome by using appropriate calibration curve fitting and the recommended value transfer protocol, which includes a minimum of two assay runs on each of at least 3 separate days, with weight correction of all reconstitutions and dilutions. An initial weight-corrected dilution should be made each day because of the relatively high level of CRP in CRM 470. In our opinion, the degree of nonlinearity, imprecision, and differences in values in currently available assays renders the use of fixed clinical decision cut-points questionable for high-sensitivity CRP. An alternative approach is suggested.

  15. ATLANTA COMMUTE VEHICLE SOAK AND START DISTRIBUTIONS AND ENGINE STARTS PER DAY: IMPACT ON MOBILE SOURCE EMISSION RATES

    EPA Science Inventory

    Georgia Institute of Technology School of Civil and Environmental Engineering researchers analyzed the 2004 vehicle activity data obtained from vehicles in the Atlanta Commuter Choice Value Pricing Initiative. The onboard monitoring equipment installed in each participating vehi...

  16. Hybrid high direct current circuit interrupter

    DOEpatents

    Rockot, Joseph H.; Mikesell, Harvey E.; Jha, Kamal N.

    1998-01-01

    A device and a method for interrupting very high direct currents (greater than 100,000 amperes) and simultaneously blocking high voltages (greater than 600 volts). The device utilizes a mechanical switch to carry very high currents continuously with low loss and a silicon controlled rectifier (SCR) to bypass the current around the mechanical switch while its contacts are separating. A commutation circuit, connected in parallel with the SCR, turns off the SCR by utilizing a resonant circuit to divert the SCR current after the switch opens.

  17. Hybrid high direct current circuit interrupter

    DOEpatents

    Rockot, J.H.; Mikesell, H.E.; Jha, K.N.

    1998-08-11

    A device and a method are disclosed for interrupting very high direct currents (greater than 100,000 amperes) and simultaneously blocking high voltages (greater than 600 volts). The device utilizes a mechanical switch to carry very high currents continuously with low loss and a silicon controlled rectifier (SCR) to bypass the current around the mechanical switch while its contacts are separating. A commutation circuit, connected in parallel with the SCR, turns off the SCR by utilizing a resonant circuit to divert the SCR current after the switch opens. 7 figs.

  18. Electron spectroscopy analysis of contact surfaces in the wear of carbon brushes against copper commutators

    NASA Astrophysics Data System (ADS)

    Savage, D. E.; Lagally, M. G.; Schrader, M. E.

    Carbon brushes and copper commutator strips have been analyzed by a combination of techniques to investigate possible surface-related phenomena in the excessive wear of carbon brushes in motors and generators. X-ray photoelectron spectroscopy, scanning Auger microscopy, optical microscopy, scanning electron microscopy, and energy-dispersive X-ray analysis were used in this study. A thin SiO 2 film, of the order of 30 Å on the brushes, and of the order of several hundred Å on the commutators, was correlated with high wear and is believed to be the chief cause of the excessive wear. Possible models for the effect of SiO 2 on carbon brush wear are discussed.

  19. Quantum Fisher information and symmetric logarithmic derivative via anti-commutators

    NASA Astrophysics Data System (ADS)

    Liu, Jing; Chen, Jie; Jing, Xiao-Xing; Wang, Xiaoguang

    2016-07-01

    The symmetric logarithmic derivative (SLD) is a key quantity to obtain quantum Fisher information (QFI) and to construct the corresponding optimal measurements. Here we develop a method to calculate the SLD and QFI via anti-commutators. This method has originated from the Lyapunov representation and would be very useful for cases where the anti-commutators among the state and its partial derivative exhibit periodic properties. As an application, we discuss a class of states whose squares linearly depend on the states themselves, and give the corresponding analytical expressions of SLD and QFI. A noisy scenario of this class of states is also considered and discussed. Finally, we readily apply the method to the block-diagonal states and the multi-parameter estimation scenarios.

  20. An ecological analysis of environmental correlates of active commuting in urban U.S.

    PubMed

    Fan, Jessie X; Wen, Ming; Kowaleski-Jones, Lori

    2014-11-01

    We conduct a cross-sectional ecological analysis to examine environmental correlates of active commuting in 39,660 urban tracts using data from the 2010 Census, 2007-2011 American Community Survey, and other sources. The five-year average (2007-2011) prevalence is 3.05% for walking, 0.63% for biking, and 7.28% for public transportation to work, with higher prevalence for all modes in lower-income tracts. Environmental factors account for more variances in public transportation to work but economic and demographic factors account for more variances in walking and biking to work. Population density, median housing age, street connectivity, tree canopy, distance to parks, air quality, and county sprawl index are associated with active commuting, but the association can vary in size and direction for different transportation mode and for higher-income and lower-income tracts.

  1. The influence of distance to school on the associations between active commuting and physical activity.

    PubMed

    Panter, Jenna; Jones, Andrew; Van Sluijs, Esther; Griffin, Simon

    2011-02-01

    The purpose of this cross-sectional study was to examine the associations between active commuting behavior, levels of physical activity and distance to school in 9-10 year old children. Participants were children (n = 1824) who took part in the SPEEDY study (Sport, Physical activity and Eating behavior: Environmental Determinants in Young people). For both boys and girls, significant positive associations were observed between walking to school and physical activity and moderate-to-vigorous physical activity during weekday journey times (8-9 am and 3-4 pm), and the size of association also became stronger with increasing distance from school. Promotion of active commuting to school might be an important way to increase levels of physical activity in school children. PMID:21467592

  2. An ecological analysis of environmental correlates of active commuting in urban U.S.

    PubMed

    Fan, Jessie X; Wen, Ming; Kowaleski-Jones, Lori

    2014-11-01

    We conduct a cross-sectional ecological analysis to examine environmental correlates of active commuting in 39,660 urban tracts using data from the 2010 Census, 2007-2011 American Community Survey, and other sources. The five-year average (2007-2011) prevalence is 3.05% for walking, 0.63% for biking, and 7.28% for public transportation to work, with higher prevalence for all modes in lower-income tracts. Environmental factors account for more variances in public transportation to work but economic and demographic factors account for more variances in walking and biking to work. Population density, median housing age, street connectivity, tree canopy, distance to parks, air quality, and county sprawl index are associated with active commuting, but the association can vary in size and direction for different transportation mode and for higher-income and lower-income tracts. PMID:25460907

  3. An approach for modeling self-commutated static power converters for photovoltaic islanding studies

    SciTech Connect

    Imece, A.F. . Systems Development and Engineering Dept.); Jones, R.A.; Sims, T.R. ); Gross, C.A. . Dept. of Electrical Engineering)

    1989-09-01

    The safety of line crew personnel and others is a major concern of electric power utilities regarding the widespread use of grid-connected photo-volataic (PV) power sources. PV sources feed power back to a utility grid through Static Power Converters (SPC's), which are designed to shut down when disconnected from the grid. SPC's have been shown to continue to operate or run-on under certain conditions. A model for a commercially available self-commutated SPC is developed to investigate the conditions under which isolated operation (islanding) occurs. The approach used in modeling the SPC is unique in islanding studies. It is based on solving complex-ac system equations and Phase-Locked Loop differential equations simultaneously to determine the SPC response. The model accurately and optimistically predicts the islanding performance of the self-commutated SPC, as verified in laboratory experiments and detailed computer simulations.

  4. Functional models for commutative systems of linear operators and de Branges spaces on a Riemann surface

    NASA Astrophysics Data System (ADS)

    Zolotarev, Vladimir A.

    2009-04-01

    Functional models are constructed for commutative systems \\{A_1,A_2\\} of bounded linear non-self-adjoint operators which do not contain dissipative operators (which means that \\xi_1A_1+\\xi_2A_2 is not a dissipative operator for any \\xi_1, \\xi_2\\in\\mathbb{R}). A significant role is played here by the de Branges transform and the function classes occurring in this context. Classes of commutative systems of operators \\{A_1,A_2\\} for which such a construction is possible are distinguished. Realizations of functional models in special spaces of meromorphic functions on Riemann surfaces are found, which lead to reasonable analogues of de Branges spaces on these Riemann surfaces. It turns out that the functions E(p) and \\widetilde E(p) determining the order of growth in de Branges spaces on Riemann surfaces coincide with the well-known Baker-Akhiezer functions. Bibliography: 11 titles.

  5. The physical environment and health-enhancing activity during the school commute: global positioning system, geographical information systems and accelerometry.

    PubMed

    McMinn, David; Oreskovic, Nicolas M; Aitkenhead, Matt J; Johnston, Derek W; Murtagh, Shemane; Rowe, David A

    2014-05-01

    Active school travel is in decline. An understanding of the potential determinants of health-enhancing physical activity during the school commute may help to inform interventions aimed at reversing these trends. The purpose of this study was to identify the physical environmental factors associated with health-enhancing physical activity during the school commute. Data were collected in 2009 on 166 children commuting home from school in Scotland. Data on location and physical activity were measured using global positioning systems (GPS) and accelerometers, and mapped using geographical information systems (GIS). Multi-level logistic regression models accounting for repeated observations within participants were used to test for associations between each land-use category (road/track/path, other man-made, greenspace, other natural) and moderate-to-vigorous physical activity (MVPA). Thirty-nine children provided 2,782 matched data points. Over one third (37.1%) of children's school commute time was spent in MVPA. Children commuted approximately equal amounts of time via natural and man-made land-uses (50.2% and 49.8% respectively). Commuting via road/track/path was associated with increased likelihood of MVPA (Exp(B)=1.23, P <0.05), but this association was not seen for commuting via other manmade land-uses. No association was noted between greenspace use and MVPA, but travelling via other natural land-uses was associated with lower odds of MVPA (Exp(B)=0.32, P <0.05). Children spend equal amounts of time commuting to school via man-made and natural land-uses, yet man-made transportation route infrastructure appears to provide greater opportunities for achieving health-enhancing physical activity levels.

  6. Characterizing multiple solutions to the time-energy canonical commutation relation via internal symmetries

    SciTech Connect

    Caballar, Roland Cristopher F.; Ocampo, Leonard R.; Galapon, Eric A.

    2010-06-15

    Internal symmetries can be used to classify multiple solutions to the time-energy canonical commutation relation (TE-CCR). The dynamical behavior of solutions to the TE-CCR possessing particular internal symmetries involving time reversal differ significantly from solutions to the TE-CCR without those particular symmetries, implying a connection between the internal symmetries of a quantum system, its internal unitary dynamics, and the TE-CCR.

  7. Are GIS-modelled routes a useful proxy for the actual routes followed by commuters?

    PubMed Central

    Dalton, Alice M; Jones, Andrew P; Panter, Jenna; Ogilvie, David

    2015-01-01

    Active commuting offers the potential to increase physical activity among adults by being built into daily routines. Characteristics of the route to work may influence propensity to walk or cycle. Geographic information system (GIS) software is often used to explore this by modelling routes between home and work. However, if the validity of modelled routes depends on the mode of travel used, studies of environmental determinants of travel may be biased. We aimed to understand how well modelled routes reflect those actually taken, and what characteristics explain these differences. We compared modelled GIS shortest path routes with actual routes measured using QStarz BT-Q1000X Global Positioning System (GPS) devices in a free-living sample of adults working in Cambridge and using varying travel modes. Predictors of differences, according to length and percentage overlap, between the two route sets were assessed using multilevel regression models and concordance coefficients. The 276 trips, made by 51 participants, were on average 27% further than modelled routes, with an average geographical overlap of 39%. However, predictability of the route depended on travel mode. For route length, there was moderate-to-substantial agreement for journeys made on foot and by bicycle. Route overlap was lowest for trips made by car plus walk (22%). The magnitude of difference depended on other journey characteristics, including travelling via intermediate destinations, distance, and use of busy roads. In conclusion, GIS routes may be acceptable for distance estimation and to explore potential routes, particularly active commuting. However, GPS should be used to obtain accurate estimates of environmental contexts in which commuting behaviour actually occurs. Public health researchers should bear these considerations in mind when studying the geographical determinants and health implications of commuting behaviour, and when recommending policy changes to encourage active travel. PMID

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Commutator identities on associative algebras, the non-Abelian Hirota difference equation and its reductions

    NASA Astrophysics Data System (ADS)

    Pogrebkov, A. K.

    2016-06-01

    We show that the non-Abelian Hirota difference equation is directly related to a commutator identity on an associative algebra. Evolutions generated by similarity transformations of elements of this algebra lead to a linear difference equation. We develop a special dressing procedure that results in an integrable non-Abelian Hirota difference equation and propose two regular reduction procedures that lead to a set of known equations, Abelian or non-Abelian, and also to some new integrable equations.

  10. Sleepiness, Long Distance Commuting and Night Work as Predictors of Driving Performance

    PubMed Central

    Di Milia, Lee; Rogers, Naomi L.; Åkerstedt, Torbjörn

    2012-01-01

    Few studies have examined the effect of working night shift and long distance commuting. We examined the association between several sleep related and demographic variables, commuting distance, night work and use of mobile phones on driving performance. We used a prospective design to recruit participants and conducted a telephone survey (n = 649). The survey collected demographic and journey details, work and sleep history and driving performance concerning the day the participant was recruited. Participants also completed the Karolinska Sleepiness Scale and the Epworth Sleepiness Scale. Night workers reported significantly more sleepiness, shorter sleep duration and commuting longer distances. Seven variables were significant predictors of lane crossing. The strongest predictor was acute sleepiness (OR = 5.25, CI, 1.42–19.49, p<0.01) followed by driving ≥150 kms (OR = 3.61, CI, 1.66–7.81, p<0.001), obtaining less than 10 hours sleep in the previous 48 hours (OR = 2.58, CI, 1.03–6.46, p<0.05), driving after night shift (OR = 2.19, CI, 1.24–3.88, p<0.001), being <43 years old (OR = 1.95, CI, 1.11–3.41, p<0.05) and using mobile phones during the journey (OR = 1.90, CI, 1.10–3.27, p<0.05). Sleep related variables, long-distance commuting and night work have a major impact on lane crossing. Several interventions should be considered to reduce the level of sleepiness in night workers. PMID:23029278

  11. Assessment of personal exposure to particulate air pollution during commuting in European cities--recommendations and policy implications.

    PubMed

    Karanasiou, Angeliki; Viana, Mar; Querol, Xavier; Moreno, Teresa; de Leeuw, Frank

    2014-08-15

    Commuting is considered as one of the high-exposure periods among various daily activities, especially in high vehicle-density metropolitan areas. There is a growing awareness of the need to change our transportation habits by reducing our use of cars and shifting instead to active transport, i.e. walking or cycling. A review was undertaken using the ISI web of knowledge database with the objective to better understand personal exposure during commuting by different modes of transport, and to suggest potential strategies to minimise exposure. The air pollutants studied include particulate matter, PM black carbon, BC and particle number concentration. We focused only in European studies in order to have comparable situation in terms of vehicle fleet and policy regulations applied. Studies on personal exposure to air pollutants during car commuting are more numerous than those dealing with other types of transport, and typically conclude by emphasising that travelling by car involves exposure to relatively high particulate matter, PM exposure concentrations. Thus, compared to other transport methods, travelling by car has been shown to involve exposure both to higher PM and BC as compared with cycling. Widespread dependence on private car transport has produced a significant daily health threat to the urban commuter. However, a forward-looking, integrated transport policy, involving the phased renovation of existing public vehicles and the withdrawal of the more polluting private vehicles, combined with incentives to use public transport and the encouragement of commuter physical exercise, would reduce commuters' exposure.

  12. The Role of Distance in Examining the Association Between Active Commuting to School and Students' Weight Status

    PubMed Central

    DeWeese, Robin; Ohri-Vachaspati, Punam

    2016-01-01

    Background Active commuting to school (ACS) increases students' daily physical activity, but associations between student weight and ACS are inconsistent. Few studies examining ACS and weight account for distance commuted. This study examines the association between students' weight status and ACS, taking into account distance to school. Methods In 2009–10 a random digit-dial household survey conducted in low-income minority cities collected information about ACS for 1 randomly selected school-going student per household. Parents provided measured heights and weights. Distance commuted was obtained using geocoded home and school addresses. Multivariate regression analyses assessed associations of ACS and distance commuted with weight status. Results 36.6% of students were overweight/obese; 47.2% engaged in ACS. Distance walked/biked to school was associated with 7% lower odds of overweight/obesity (OR = 0.93, 95% CI: 0.88–0.99). Without distance commuted in the model, ACS was not associated with students' weight status. Compared with no ACS, ACS greater than a half-mile was associated with 65% lower odds of a student being overweight/obese (OR = 0.35, 95% CI: 0.16–0.78); ACS less than a half-mile was not. Conclusions ACS is significantly inversely associated with overweight/obesity among students who commute beyond a one-half mile threshold. PMID:25473961

  13. Assessment of personal exposure to particulate air pollution during commuting in European cities--recommendations and policy implications.

    PubMed

    Karanasiou, Angeliki; Viana, Mar; Querol, Xavier; Moreno, Teresa; de Leeuw, Frank

    2014-08-15

    Commuting is considered as one of the high-exposure periods among various daily activities, especially in high vehicle-density metropolitan areas. There is a growing awareness of the need to change our transportation habits by reducing our use of cars and shifting instead to active transport, i.e. walking or cycling. A review was undertaken using the ISI web of knowledge database with the objective to better understand personal exposure during commuting by different modes of transport, and to suggest potential strategies to minimise exposure. The air pollutants studied include particulate matter, PM black carbon, BC and particle number concentration. We focused only in European studies in order to have comparable situation in terms of vehicle fleet and policy regulations applied. Studies on personal exposure to air pollutants during car commuting are more numerous than those dealing with other types of transport, and typically conclude by emphasising that travelling by car involves exposure to relatively high particulate matter, PM exposure concentrations. Thus, compared to other transport methods, travelling by car has been shown to involve exposure both to higher PM and BC as compared with cycling. Widespread dependence on private car transport has produced a significant daily health threat to the urban commuter. However, a forward-looking, integrated transport policy, involving the phased renovation of existing public vehicles and the withdrawal of the more polluting private vehicles, combined with incentives to use public transport and the encouragement of commuter physical exercise, would reduce commuters' exposure. PMID:24907613

  14. Using Geographic Information Systems to Define and Map Commuting Patterns as Inputs to Agent-Based Models

    PubMed Central

    Chrest, David P.; Wheaton, William D.

    2010-01-01

    By understanding the movement patterns of people, mathematical modelers can develop models that can better analyze and predict the spread of infectious diseases. People can come into close contact in their workplaces. This report describes methods to develop georeferenced commuting patterns that can be used to characterize the work-related movement of US populations and help agent-based modelers predict workplace contacts that result in disease transmission. We used a census data product called “Census Spatial Tabulation: Census Track of Work by Census Tract of Residence (STP64)” as the data source to develop commuting pattern data for agent-based synthesized populations databases and to develop map products to visualize commuting patterns in the United States. The three primary maps we developed show inbound, outbound, and net change levels of inbound versus outbound commuters by census tract for the year 2000. Net change counts of commuters are visualized as elevations. The results can be used to quantify and assign commuting patterns of synthesized populations among different census tracts. PMID:20505785

  15. Epidemic dynamics of a vector-borne disease on a villages-and-city star network with commuters.

    PubMed

    Mpolya, Emmanuel A; Yashima, Kenta; Ohtsuki, Hisashi; Sasaki, Akira

    2014-02-21

    We develop a star-network of connections between a central city and peripheral villages and analyze the epidemic dynamics of a vector-borne disease as influenced by daily commuters. We obtain an analytical solution for the global basic reproductive number R0 and investigate its dependence on key parameters for disease control. We find that in a star-network topology the central hub is not always the best place to focus disease intervention strategies. Disease control decisions are sensitive to the number of commuters from villages to the city as well as the relative densities of mosquitoes between villages and city. With more commuters it becomes important to focus on the surrounding villages. Commuting to the city paradoxically reduces the disease burden even when the bulk of infections are in the city because of the resulting diluting effects of transmissions with more commuters. This effect decreases with heterogeneity in host and vector population sizes in the villages due to the formation of peripheral epicenters of infection. We suggest that to ensure effective control of vector-borne diseases in star networks of villages and cities it is also important to focus on the commuters and where they come from.

  16. Boundedness of certain commutators over non-homogeneous metric measure spaces

    NASA Astrophysics Data System (ADS)

    Lin, Haibo; Wu, Suqing; Yang, Dachun

    2016-06-01

    Let ({X},d,μ ) be a metric measure space satisfying the so-called upper doubling condition and the geometrically doubling condition. Let T be a Calderón-Zygmund operator with kernel satisfying only the size condition and some Hörmander-type condition, and bin widetilde{RBMO}(μ ) (the regularized BMO space with the discrete coefficient). In this paper, the authors establish the boundedness of the commutator T_b:=bT-Tb generated by T and b from the atomic Hardy space widetilde{H}^1(μ ) with the discrete coefficient into the weak Lebesgue space L^{1, ∞}(μ ) . From this and an interpolation theorem for sublinear operators which is also proved in this paper, the authors further show that the commutator T_b is bounded on L^p(μ ) for all pin (1,∞) . Moreover, the boundedness of the commutator generated by the generalized fractional integral T_α (α in (0,1)) and the widetilde{RBMO}(μ ) function from widetilde{H}^1(μ ) into L^{1/{(1-α )}, ∞}(μ ) is also presented.

  17. The FM-007: An advanced jet commuter for HUB to spoke transportation

    NASA Technical Reports Server (NTRS)

    Blouke, Peter Scott; Engel, George Bryan; Fordham, Kari Suzanne; Layne, Steven James; Moore, Joel David; Shaver, Frederick Martin; Thornton, Douglas Hershal, Jr.

    1991-01-01

    Due to the increasing need for new commuter aircraft, the FM-007 is proposed, a technologically advanced jet propelled short takeoff and landing (STOL) airplane. The proposed commuter is designed for hub to spoke air travel. In order to reduce drag, natural laminar flow technology is integrated into the design using the natural laminar flow airfoil section for the wing. A three lifting surface configuration provides for more efficient cruise flight. This unique design includes a small forward wing (canard), a rear mounted high aspect ratio main wing, and a small horizontal stabilizer high atop the vertical tail. These three surfaces act together to reduce drag by minimizing the downward force the horizontal stabilizer has to account for due to the nose down pitching moment. Commuter aircraft must also incorporate passenger comfort. This is achieved by providing a spacious pressurized cabin with a large galley and reduced cabin noise due to incorporation of noise reduction gear. A basic oval design is adopted, as opposed to a circular design in order to allow for the seating of five passengers abreast. To get STOL capability, an over the wing blown flap is used using a Rolls Royce Tay series engine.

  18. Commute time distance transformation applied to spectral imagery and its utilization in material clustering

    NASA Astrophysics Data System (ADS)

    Albano, James A.; Messinger, David W.; Rotman, Stanley R.

    2012-07-01

    Spectral image analysis problems often begin by applying a transformation that generates an alternative representation of the spectral data with the intention of exposing hidden features not discernable in the original space. We introduce and demonstrate a transformation based on a Markov-chain model of a random walk on a graph via application to spectral image clustering. The random walk is quantified by a measure known as the average commute time distance (CTD), which is the average length that a random walker takes, when starting at one node, to transition to another and return to the starting node. This distance metric has the important characteristic of increasing when the number of paths between two nodes decreases and/or the lengths of those paths increase. Once a similarity graph is built on the spectral data, a transformation based on an eigendecomposition of the graph Laplacian matrix is applied that embeds the nodes of the graph into a Euclidean space with the separation between nodes equal to the square-root of the average commute time distance. This is referred to as the Commute Time Distance transformation. As an example of the utility of this data transformation, results are shown for standard clustering algorithms applied to hyperspectral data sets.

  19. Features of a Health-Oriented Education Program during Daily Commutes: A Qualitative Study

    PubMed Central

    Ramezankhani, Ali; Heydarabadi, Akbar Babaei; Ghaffari, Mohtasham; Mehrabi, Yadollah; Kazemi, Sadegh

    2016-01-01

    Introduction Today, despite scientific advances, many people spend more time and distance between home and their workplaces because of various economic and population reasons. The aim of this study was to identify features of an appropriate health education program during commutes for factory staff at Ardakan county (Yazd province, Iran). Methods This qualitative study was conducted via the phenomenological method in 2014. The population of this study was members of the staff of Ardakan Steel Company. Nineteen specialists and 11 members of the factory’s staff were invited to participate in the study, and data were collected using semi-structured interviews. The interviews took 20 to 40 minutes, and their content was analyzed using content analysis. Results Extraction of codes and themes and their placement in this study showed that an educational program during commutes should have nine features to have the desired effectiveness, i.e., the program must be audience-oriented, repeatable, participatory, technology-based, combinational, supportive, and motivational and interesting. Also, the program should have environmental and organizational support, and it must be evaluated for its effectiveness. Conclusion Considering appropriate features of a health education program in educational situations, especially interventions related to daily commutes, is very important because the effectiveness of such health-oriented educational programs must be ensured. PMID:27504166

  20. Multi-commutated fluorometric optosensor for the determination of citrinin in rice and red yeast rice supplements.

    PubMed

    Jiménez-López, J; Llorent-Martínez, E J; Ortega-Barrales, P; Ruiz-Medina, A

    2014-01-01

    Citrinin is a toxic secondary metabolite first isolated from Penicillium citrinum, although is also produced by other species of Penicillium and Aspergillus. It has highly toxic, mutagenic, teratogenic and carcinogenic properties and is often found in crops, vegetables and fruit. To our knowledge there is no specific legislation on maximum levels permitted for citrinin, so no official analytical method is currently available for its determination. Our laboratory developed a fluorometric flow-through optosensor using Sephadex SPC-25 as solid support. Multi-commutated flow injection analysis was used for the construction of the manifold and for handling solutions. In this way, we minimised waste generation and human intervention, which are critical aspects when dealing with highly toxic compounds such as citrinin. The optimum excitation/emission wavelengths were set at 330/494 nm; the calibration curve was linear in the concentration range 35-900 ng ml⁻¹. A detection limit of 10.5 ng ml⁻¹ and relative standard deviations (RSDs) lower than 3% were obtained. The developed optosensor was applied to the determination of citrinin in rice and dietary supplements containing red yeast rice.

  1. Aging commuter aeroplanes: Fatigue evaluation and control methods

    NASA Technical Reports Server (NTRS)

    Emmerson, A. J.

    1992-01-01

    The loss of reliability in aircraft is caused by two broad classes of problems. There are those problems which are self evident and hazardous rather than catastrophic. These are the problem areas where characteristically there have been multiple overhauls, repairs, and replacements, and where aging really means the results of repair ineffectiveness that accumulates. The other class of the problem is the insidious and potentially catastrophic class. It includes the progressive deterioration of items that are not maintained, and often cannot be maintained because the deterioration cannot be seen. It includes the loss of physical properties in adhesives and other organic compounds, corrosion, and the response of repeated loads. Dealt with here is a currently unnecessarily troublesome aspect of that response. Although we must remain concerned about those types of aircraft which have been certified under a design standard or operational rule which embodies the elementary fail-safe concept and which have not been subjected to a subsequent structural audit, the focus here is on types of aircraft for which fatigue and damage tolerance evaluation was not required as a condition of certification.

  2. Elimination of current spikes in buck power converters

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T. (Inventor)

    1981-01-01

    Current spikes in a buck power converter due to commutating diode turn-off time are eliminated by using a tapped inductor in the converter with the tap connected to the switching transistor. The commutating diode is not in the usual place, but is instead connected to conduct current from one end of the tapped inductor remote from the load during the interval in which the transistor is not conducting. In the case of a converter having a center-tapped (primary and secondary) transformer between two switching power transistors operated in a push-pull mode and two rectifying diodes in the secondary circuit, current spikes due to transformer saturation are also eliminated by using a tapped inductor in the converter with the tap connected to the rectifying diodes and a diode connected to conduct current from one end of the tapped inductor remote from the load during the interval in which the transistors are not conducting.

  3. Influence of Sports, Physical Education, and Active Commuting to School on Adolescent Weight Status

    PubMed Central

    Beach, Michael L.; Longacre, Meghan R.; MacKenzie, Todd; Titus, Linda J.; Rundle, Andrew G.; Dalton, Madeline A.

    2012-01-01

    OBJECTIVE: To compare the associations between weight status and different forms of physical activity among adolescents. METHODS: We conducted telephone surveys with 1718 New Hampshire and Vermont high school students and their parents as part of a longitudinal study of adolescent health. We surveyed adolescents about their team sports participation, other extracurricular physical activity, active commuting, physical education, recreational activity for fun, screen time, diet quality, and demographics. Overweight/obesity (BMI for age ≥ 85th percentile) and obesity (BMI for age ≥ 95 percentile) were based on self-reported height and weight. RESULTS: Overall, 29.0% (n = 498) of the sample was overweight/obese and 13.0% (n = 223) were obese. After adjustments, sports team participation was inversely related to overweight/obesity (relative risk [RR] = 0.73 [95% confidence interval (CI): 0.61, 0.87] for >2 sports teams versus 0) and obesity (RR = 0.61 [95% CI: 0.45, 0.81] for >2 sports teams versus 0). Additionally, active commuting to school was inversely related to obesity (RR = 0.67 [95% CI: 0.45, 0.99] for >3.5 days per week versus 0). Attributable risk estimates suggest obesity prevalence would decrease by 26.1% (95% CI: 9.4%, 42.8%) if all adolescents played on 2 sports teams per year and by 22.1% (95% CI: 0.1%, 43.3%) if all adolescents walked/biked to school at least 4 days per week. CONCLUSIONS: Team sport participation had the strongest and most consistent inverse association with weight status. Active commuting to school may reduce the risk of obesity, but not necessarily overweight, and should be studied further. Obesity prevention programs should consider strategies to increase team sport participation among all students. PMID:22802608

  4. Commuters' exposure to PM1 by common travel modes in Shanghai

    NASA Astrophysics Data System (ADS)

    Yu, Qi; Lu, Yi; Xiao, Shan; Shen, Junxiu; Li, Xun; Ma, Weichun; Chen, Limin

    2012-11-01

    A study on commuter's exposure to PM1 in Shanghai was presented. Commuters' real-time exposure concentrations by the common travel modes (bus, walking, cycling, taxi and subway) were measured by DustTrak™ dust monitors, and the average exposure concentrations and inhalation doses were analyzed. The lengths of the routes were designed to be within 30-min walking distance. The average PM1 exposure concentrations during commuting were 0.147 ± 0.092 mg m-3, 0.145 ± 0.088 mg m-3, 0.140 ± 0.086 mg m-3, 0.139 ± 0.086 mg m-3 and 0.122 ± 0.077 mg m-3 for the bus, walking, cycling, taxi and subway trips respectively. The concentrations in the microenvironments were 0.147 ± 0.096 mg m-3, 0.155 ± 0.098 mg m-3, 0.142 ± 0.092 mg m-3 and 0.079 ± 0.051 mg m-3 for the bus station, bus, taxi and train respectively. The concentrations in the microenvironments were close to those in Guangzhou and higher compared to the results in London, Sydney, Florence, etc. The combined effect of exposure concentration, travel time and inhalation rate led to different inter-mode relationship of inhalation doses compared to that of exposure concentrations. The inhalation doses were 54.5 ± 38.9 μg, 45.2 ± 30.1 μg, 29.2 ± 25.4 μg, 28.6 ± 25.9 μg and 12.8 ± 13.4 μg for the cycling, walking, bus, subway and taxi trips respectively. The outdoor fractions of the inhalation doses by bus, taxi and subway were much higher than the indoor fractions.

  5. Unified commutation-pruning technique for efficient computation of composite DFTs

    NASA Astrophysics Data System (ADS)

    Castro-Palazuelos, David E.; Medina-Melendrez, Modesto Gpe.; Torres-Roman, Deni L.; Shkvarko, Yuriy V.

    2015-12-01

    An efficient computation of a composite length discrete Fourier transform (DFT), as well as a fast Fourier transform (FFT) of both time and space data sequences in uncertain (non-sparse or sparse) computational scenarios, requires specific processing algorithms. Traditional algorithms typically employ some pruning methods without any commutations, which prevents them from attaining the potential computational efficiency. In this paper, we propose an alternative unified approach with automatic commutations between three computational modalities aimed at efficient computations of the pruned DFTs adapted for variable composite lengths of the non-sparse input-output data. The first modality is an implementation of the direct computation of a composite length DFT, the second one employs the second-order recursive filtering method, and the third one performs the new pruned decomposed transform. The pruned decomposed transform algorithm performs the decimation in time or space (DIT) data acquisition domain and, then, decimation in frequency (DIF). The unified combination of these three algorithms is addressed as the DFTCOMM technique. Based on the treatment of the combinational-type hypotheses testing optimization problem of preferable allocations between all feasible commuting-pruning modalities, we have found the global optimal solution to the pruning problem that always requires a fewer or, at most, the same number of arithmetic operations than other feasible modalities. The DFTCOMM method outperforms the existing competing pruning techniques in the sense of attainable savings in the number of required arithmetic operations. It requires fewer or at most the same number of arithmetic operations for its execution than any other of the competing pruning methods reported in the literature. Finally, we provide the comparison of the DFTCOMM with the recently developed sparse fast Fourier transform (SFFT) algorithmic family. We feature that, in the sensing scenarios with

  6. Cooperative Learning in Organic II. Increased Retention on a Commuter Campus

    NASA Astrophysics Data System (ADS)

    Hagen, James P.

    2000-11-01

    Modest use of cooperative learning techniques combined with extensive class notes produced a significant increase in retention for the second semester of organic chemistry on a commuter campus. The cooperative learning techniques included group testing, think-write-compare problems, and muddiest point essays. The first group take-home quiz must be carefully constructed and persuasively introduced to the class. An example is given. The increase in retention did not decrease class performance on standardized ACS exams, which was above the norms. Anecdotal student response to these techniques was largely positive. Student evaluation of instructor teaching improved modestly.

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

    PubMed

    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

  8. [New artificial lung respiration apparatuses for anesthesia and design of gas flow commutators].

    PubMed

    Reĭderman, E N; Sterlin, Iu G; Trushin, A I; Maiakov, A A; Nemirovskiĭ, S B; Tsvik, A I

    2005-01-01

    The principles of action of new anesthetic devices and apparatuses for mechanical lung ventilation (MLV) including alternate-flow inhalation generators designed in recent time in VNIIMP-VITA, Ltd. are considered. According to the type of drive, these apparatuses fall into groups of devices with pneumatic drive (Diana) and electric drive (Elan). New technological approaches to design of gas flow commutators for pneumatic drive and respiratory contours of MLV apparatuses are discussed. The design of a new source of stable pneumatic signals providing reliable operation of the control valves of the inhalation and exhalation contours of electrically driven apparatuses. This source allows necessary MLV modes to be implemented during anesthesia. PMID:16491662

  9. Reducibility of invertible tuples to the principal component in commutative Banach algebras

    NASA Astrophysics Data System (ADS)

    Mortini, Raymond; Rupp, Rudolf

    2016-10-01

    Let A be a complex, commutative unital Banach algebra. We introduce two notions of exponential reducibility of Banach algebra tuples and present an analogue to the Corach-Suárez result on the connection between reducibility in A and in C(M(A)). Our methods are of an analytical nature. Necessary and sufficient geometric/topological conditions are given for reducibility (respectively reducibility to the principal component of Un(A)) whenever the spectrum of A is homeomorphic to a subset of {C}n.

  10. Globalism of commutation relation and mechanism of momentum transfer in the Aharonov-Bohm effect

    NASA Astrophysics Data System (ADS)

    Li, Chun-Fang

    1997-09-01

    After examining the domain of an operator that has classical analog, which is shown to be the whole spatial space, the concept of globalism of a commutation relation is introduced through analyzing the quantization of the kinetic angular momentum in the Aharonov-Bohm effect. Its applications are also given to explain in an elegant and precise way, the mechanism of momentum transfer in the Aharonov-Bohm scattering and to study the probability distribution of the momentum for a particle in a one-dimensional infinitely deep square potential well.

  11. On linear groups of degree 2 over a finite commutative ring

    SciTech Connect

    Bashkirov, Evgenii L.; Eser, Hasan

    2014-08-20

    Let p > 3 be a prime number and F{sub p} be a field of p elements. Let K be a commutative and associative ring obtained by adjoining to F{sub p} an element α such that α satisfies a polynomial over F{sub p} and a polynomial of the least degree whose root is α can be written as a product of distinct polynomials irreducible over F{sub p}. We prove that the special linear group SL{sub 2}(K) is generated by two elementary transvections ( (table) ), ( (table) )

  12. The Langley turbo-prop commuter design: A complete project description

    NASA Technical Reports Server (NTRS)

    Buttram, Greg; Horton, Keith; Keeter, Tim; Millhouse, Paul; Newberry, Kelli; Obyrne, Brian

    1991-01-01

    The primary objective of this project was to propose and prove the possibility of a new, advanced technology commuter aircraft design. Among the specifications were short to medium range capabilities, low seat per mile cost, fuel efficiency, and passenger comfort. Based on market evaluation, we found that the optimum size for new regional aircraft is around 50 passengers; we have designed our aircraft for this capacity. Turboprop engines provide substantial reductions in operating costs due to lower fuel consumption. We have therefore chosen an advanced turboprop engine. Composite materials, while more expensive to purchase and manufacture, result in decreased costs later through weight savings and ease of replacement.

  13. Sagnac interferometry as a probe to the commutation relation of a macroscopic quantum mirror

    SciTech Connect

    Yang Ran; Gong Xuefei; Pei Shouyong; Luo Ziren; Lau, Y. K.

    2010-09-15

    Single photon Sagnac interferometry as a probe to macroscopic quantum mechanics is considered at the theoretical level. For a freely moving macroscopic quantum mirror susceptible to radiation pressure force inside a Sagnac interferometer, a careful analysis of the input-output relation reveals that the particle spectrum readout at the bright and dark ports encode information concerning the noncommutativity of position and momentum of the macroscopic mirror. A feasible experimental scheme to probe the commutation relation of a macroscopic quantum mirror is outlined to explore the possible frontier between classical and quantum regimes. In the Appendix, the case of Michelson interferometry as a feasible probe is also sketched.

  14. On Weyl channels being covariant with respect to the maximum commutative group of unitaries

    SciTech Connect

    Amosov, Grigori G.

    2007-01-15

    We investigate the Weyl channels being covariant with respect to the maximum commutative group of unitary operators. This class includes the quantum depolarizing channel and the 'two-Pauli' channel as well. Then, we show that our estimation of the output entropy for a tensor product of the phase damping channel and the identity channel based upon the decreasing property of the relative entropy allows to prove the additivity conjecture for the minimal output entropy for the quantum depolarizing channel in any prime dimension and for the two-Pauli channel in the qubit case.

  15. Evaluation of a workplace intervention to promote commuter cycling: A RE-AIM analysis

    PubMed Central

    2013-01-01

    Background Originating from the interdisciplinary collaboration between public health and the transportation field a workplace intervention to promote commuter cycling, ‘Bike to Work: cyclists are rewarded’, was implemented. The intervention consisted of two cycling contests, an online loyalty program based on earning ‘cycling points’ and the dissemination of information through folders, newsletters, posters and a website. The study purpose was to evaluate the dissemination efforts of the program and to gain insights in whether free participation could persuade small and middle-sized companies to sign up. Methods The RE-AIM framework was used to guide the evaluation. Two months after the start of the intervention a questionnaire was send to 4880 employees. At the end of the intervention each company contact person (n = 12) was interviewed to obtain information on adoption, implementation and maintenance. Comparison analyses between employees aware and unaware of the program were conducted using independent-samples t-tests for quantitative data and chi-square tests for qualitative data. Difference in commuter cycling frequency was assessed using an ANOVA test. Non-parametric tests were used for the comparison analyses between the adopting and non-adopting companies. Results In total seven of the twelve participating companies adopted the program and all adopting companies implemented all intervention components. No significant differences were found in the mean number of employees (p = 0.15) or in the type of business sector (p = 0.92) between adopting and non-adopting companies. Five out of seven companies had the intention to continue the program. At the individual level, a project awareness of 65% was found. Employees aware of the program had a significantly more positive attitude towards cycling and reported significantly more commuter cycling than those unaware of the program (both p < 0.001). Participation was mainly because of health

  16. Wick Product for Commutation Relations Connected with Yang-Baxter Operators and New Constructions of Factors

    NASA Astrophysics Data System (ADS)

    Krsolarlak, Ilona

    We analyze a certain class of von Neumann algebras generated by selfadjoint elements , for satisfying the general commutation relations: Such algebras can be continuously embedded into some closure of the set of finite linear combinations of vectors , where is an orthonormal basis of a Hilbert space . The operator which represents the vector is denoted by and called the ``Wick product'' of the operators . We describe explicitly the form of this product. Also, we estimate the operator norm of for . Finally we apply these two results and prove that under the assumption all the von Neumann algebras considered are II1 factors.

  17. Propositions for the Analysis of Commutation Phenomena and Modeling of Universal Motors Using the State Function Method

    NASA Astrophysics Data System (ADS)

    Niwa, Yuta; Akiyama, Yuji; Naruta, Tomokazu

    We carried out FEM simulations for modeling ultra-high-speed universal motors by using the state function method and analyzed the phenomenon of commutator sparking, the characteristics of the air gap surface, and the contact condition or contact resistance of the brushes and commutator bars. Thus, we could quantitatively analyze commutator sparking and investigate the configuration of the iron core. The results of FEM analysis were used to develop a model for predicting the configuration of the iron core and for estimating the electromotive force generated by the transformer, armature reaction field, spark voltage, contact resistance between the rotating brushes, and changes in the gap permeance. The results of our simulation were experimental results. This confirmed the validity of our analysis method. Thus, an ultra-high-speed, high-capacity of 1.5kw motor rotating at 30,000rpm can be designed for use in vacuum cleaners.

  18. Houston `smart commuter` its operational test: FY 1995 status report. Interim research report, September 1994-August 1995

    SciTech Connect

    Turnbull, K.F.; Higgins, L.L.

    1995-11-01

    The Houston Smart Commuter ITS Operational Test is assessing the potential to gain more efficient use of major travel corridors through greater utilization of high-occupancy commute modes, shifts in travel routes, and changes in time of travel through the application of innovative approaches using advanced technologies. The Houston Smart Commuter ITS Operational Test is a federally sponsored project and is being jointly funded by the Metropolitan Transit Authority of Harris County (METRO), the Texas Department of Transportation (TxDOT), the Federal Highway Administration (FHWA), and the Federal Transit Administration (FTA). The project contains two different, but compatible, components. One component focuses on encouraging a mode shift from driving alone to riding the bus through the provision of real-time traffic and transit information. The second component encourages carpooling through the use of real-time ridematching services.

  19. Ethnic Minority Children’s Active Commuting to School and Association with Physical Activity and Pedestrian Safety Behaviors*

    PubMed Central

    Mendoza, Jason A.; Watson, Kathy; Baranowski, Tom; Nicklas, Theresa A.; Uscanga, Doris K.; Nguyen, Nga; Hanfling, Marcus J.

    2011-01-01

    Background Children’s active commuting to school, i.e. walking or cycling to school, was associated with greater moderate-to-vigorous physical activity, although studies among ethnic minorities are sparse. Objectives Among a low-income, ethnic minority sample of fourth grade students from eight public schools, we examined (1) correlates of active commuting to school and (2) the relationship between active commuting to school and moderate-to-vigorous physical activity. Methods We conducted a cross-sectional analysis of baseline measurements from a sample of participants (n=149) aged 9–12 years from a walk to school intervention study in Houston, Texas. The primary outcome was the weekly rate of active commuting to school. Daily moderate-to-vigorous physical activity, measured by accelerometers, was a secondary outcome. Child self-efficacy (alpha=0.75), parent self-efficacy (alpha=0.88), and parent outcome expectations (alpha=0.78) were independent variables. Participant characteristics (age, gender, race/ethnicity, distance from home to school, acculturation, and BMI percentile) were independent sociodemographic variables. We used mixed-model regression analyses to account for clustering by school and a stepwise procedure with backward elimination of non-significant interactions and covariates to identify significant moderators and predictors. School-level observations of student pedestrians were assessed and compared using chi-square tests of independence. Results Among our sample, which was 61.7% Latino, the overall rate of active commuting to school was 43%. In the mixed model for active commuting to school, parent self-efficacy (std. beta = 0.18, p=0.018) and age (std. beta = 0.18, p=0.018) were positively related. Latino students had lower rates of active commuting to school than non-Latinos ( 16.5%, p=0.040). Distance from home to school was inversely related to active commuting to school (std. beta = 0.29, p<0.001). In the mixed model for moderate

  20. The Effect of Commuting Patterns on HIV Care Attendance Among Men Who Have Sex With Men (MSM) in Atlanta, Georgia

    PubMed Central

    Kramer, Michael R; Rosenberg, Eli S; Sanchez, Travis H; Reed, Landon; Sullivan, Patrick S

    2015-01-01

    Background Travel-related barriers to human immunodeficiency virus (HIV) care, such as commute time and mode of transportation, have been reported in the United States. Objective The objective of the study was to investigate the association between public transportation use and HIV care attendance among a convenience sample of Atlanta-based, HIV-positive men who have sex with men (MSM), evaluate differences across regions of residence, and estimate the relationship between travel distance and time by mode of transportation taken to attend appointments. Methods We used Poisson regression to estimate the association between use of public transportation to attend HIV-related medical visits and frequency of care attendance over the previous 12 months. The relationship between travel distance and commute time was estimated using linear regression. Kriging was used to interpolate commute time to visually examine geographic differences in commuting patterns in relation to access to public transportation and population-based estimates of household vehicle ownership. Results Using public transportation was associated with lower rates of HIV care attendance compared to using private transportation, but only in south Atlanta (south: aRR: 0.75, 95% CI 0.56, 1.0, north: aRR: 0.90, 95% CI 0.71, 1.1). Participants living in south Atlanta were more likely to have longer commute times associated with attending HIV visits, have greater access to public transportation, and may live in areas with low vehicle ownership. A majority of attended HIV providers were located in north and central Atlanta, despite there being participants living all across the city. Estimated commute times per mile traveled were three times as high among public transit users compared to private transportation users. Conclusions Improving local public transit and implementing use of mobile clinics could help address travel-related barriers to HIV care. PMID:27227128

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

    PubMed

    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. PMID:25638696

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

    PubMed

    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.

  3. Factors related to pilot survival in helicopter commuter and air taxi crashes.

    PubMed

    Krebs, M B; Li, G; Baker, S P

    1995-02-01

    We examined factors related to pilot survival in 167 consecutive helicopter commuter and air taxi crashes that occurred during 1983-88. Case fatality rates and adjusted odds ratios from multivariate logistic regression models were determined using data from the National Transportation Safety Board (NTSB). During this 6-year period, 29 pilots-in-command died in 167 helicopter commuter and air taxi crashes, a case fatality rate of 17.4%. Factors significantly associated with increased risk of pilot fatality were aircraft fire [odds ratio (OR) 20.0, 95% confidence interval (CI) 4.6-86.8], not using shoulder harnesses (OR 9.2, 95% CI 2.2-37.3), and aircraft with two engines (OR 4.8, 95% CI 1.3-17.4). In addition, we present data regarding success and failure of emergency flotation devices. The results suggest that the likelihood of pilot survival in helicopter crashes could be greatly improved by preventing crash associated fires and promoting the usage of shoulder restraints.

  4. Cosmic microwave background polarization in non-commutative space-time

    NASA Astrophysics Data System (ADS)

    Tizchang, S.; Batebi, S.; Haghighat, M.; Mohammadi, R.

    2016-09-01

    In the standard model of cosmology (SMC) the B-mode polarization of the CMB can be explained by the gravitational effects in the inflation epoch. However, this is not the only way to explain the B-mode polarization for the CMB. It can be shown that the Compton scattering in the presence of a background, besides generating a circularly polarized microwave, can lead to a B-mode polarization for the CMB. Here we consider the non-commutative (NC) space-time as a background to explore the CMB polarization at the last scattering surface. We obtain the B-mode spectrum of the CMB radiation by scalar perturbation of metric via a correction on the Compton scattering in NC-space-time in terms of the circular polarization power spectrum and the non-commutative energy scale. It can be shown that even for the NC scale as large as 20 TeV the NC-effects on the CMB polarization and the r parameter are significant. We show that the V-mode power spectrum can be obtained in terms of linearly polarized power spectrum in the range of micro- to nano-kelvin squared for the NC scale of about 1-20 TeV, respectively.

  5. The green valley: the use of mobile narratives for reducing stress in commuters.

    PubMed

    Grassi, Alessandra; Gaggioli, Andrea; Riva, Giuseppe

    2009-04-01

    New technologies have influenced communication and interaction among people, enabling them to overcome face-to-face limitations and eliminating the need for persons in a communicative relationship to be in the same place at the same time. This project aimed to test the effectiveness of mobile phone usage applied to emotion induction. The authors wanted to check whether or not mobile narratives supported by multimedia mobile phones can enhance relaxation and reduce anxiety in a sample of commuters. The project sample consisted of 120 commuters, college students aged 20 to 25 years. The sample was randomly assigned into four conditions: the Vidnar group experienced the mobile narrative on a mobile phone during their daily train trip; the Nonar group experienced only video content proposed on a mobile phone; the MP3 group experienced only the audio content proposed on an MP3 player; and the Control group provided a no-intervention condition. The study measured participants' emotional state (State-Trait Anxiety Inventory [STAI] State questionnaire), trait (STAI Trait questionnaire, Generalized Self-Efficacy Scale), and sense of presence (Slater-Usoh-Steed Questionnaire [UCL-SUS] and the International Test Commission-Sense of Presence Inventory [ITC-SOPI]) before and after the experience. The main results showed a significant decrease in anxiety level (p < 0.05, assessed by STAI State questionnaire) and an increase in relaxation level (p < 0.001) assessed by the Visual Analog Scale (VAS). No significant differences were found in other conditions. PMID:19275475

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

    PubMed

    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.

  7. Quantum error suppression with commuting Hamiltonians: two local is too local.

    PubMed

    Marvian, Iman; Lidar, Daniel A

    2014-12-31

    We consider error suppression schemes in which quantum information is encoded into the ground subspace of a Hamiltonian comprising a sum of commuting terms. Since such Hamiltonians are gapped, they are considered natural candidates for protection of quantum information and topological or adiabatic quantum computation. However, we prove that they cannot be used to this end in the two-local case. By making the favorable assumption that the gap is infinite, we show that single-site perturbations can generate a degeneracy splitting in the ground subspace of this type of Hamiltonian which is of the same order as the magnitude of the perturbation, and is independent of the number of interacting sites and their Hilbert space dimensions, just as in the absence of the protecting Hamiltonian. This splitting results in decoherence of the ground subspace, and we demonstrate that for natural noise models the coherence time is proportional to the inverse of the degeneracy splitting. Our proof involves a new version of the no-hiding theorem which shows that quantum information cannot be approximately hidden in the correlations between two quantum systems. The main reason that two-local commuting Hamiltonians cannot be used for quantum error suppression is that their ground subspaces have only short-range (two-body) entanglement.

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

    PubMed

    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. PMID:25073057

  9. The daily commute from work to home: examining employees' experiences in relation to their recovery status.

    PubMed

    van Hooff, Madelon L M

    2015-04-01

    Sufficient recovery after daily effort expenditure at work is important to protect employee health and well-being. However, the role of commuting in the daily effort-recovery process is still not very well understood. The present study aimed to advance insight in this respect by examining if relaxation, detachment, mastery and stressful delays experienced during the commute from work to home affect employees' recovery status after returning home from work and at the end of the evening. Daily job demands were expected to moderate these effects. Serenity and (low) anxiety were included as indicators of employees' recovery status. Data were collected by means of a 5-day daily diary study (three measurements daily) among 76 participants from various industries. Multilevel analyses showed that relaxation was positively and stressful delays were negatively related to employees' recovery status after returning home from work but not to indicators of recovery at the end of the evening. For detachment, similar relations were found but only on days with high job demands. Mastery was not related to employees' recovery status. These findings enhance our insight in the daily effort-recovery cycle and underline the importance of promoting detachment (on demanding workdays) and relaxation on the way home from work. PMID:24124028

  10. The daily commute from work to home: examining employees' experiences in relation to their recovery status.

    PubMed

    van Hooff, Madelon L M

    2015-04-01

    Sufficient recovery after daily effort expenditure at work is important to protect employee health and well-being. However, the role of commuting in the daily effort-recovery process is still not very well understood. The present study aimed to advance insight in this respect by examining if relaxation, detachment, mastery and stressful delays experienced during the commute from work to home affect employees' recovery status after returning home from work and at the end of the evening. Daily job demands were expected to moderate these effects. Serenity and (low) anxiety were included as indicators of employees' recovery status. Data were collected by means of a 5-day daily diary study (three measurements daily) among 76 participants from various industries. Multilevel analyses showed that relaxation was positively and stressful delays were negatively related to employees' recovery status after returning home from work but not to indicators of recovery at the end of the evening. For detachment, similar relations were found but only on days with high job demands. Mastery was not related to employees' recovery status. These findings enhance our insight in the daily effort-recovery cycle and underline the importance of promoting detachment (on demanding workdays) and relaxation on the way home from work.

  11. Application of an Ir tracer to determine soot exposure to students commuting to school on Baltimore public buses

    NASA Astrophysics Data System (ADS)

    Wu, Charles C.; Suarez, Ana E.; Lin, Zhibo; Kidwell, Christopher B.; Borgoul, Polina V.; Caffrey, Peter F.; Ondov, John M.; Sattler, Barbara

    An important component of urban aerosol, diesel soot is a known respiratory irritant and contains mutagenic and carcinogenic organic compounds. To estimate student exposures to soot emitted from public diesel buses during commutes to city high schools, a portion of the Baltimore municipal fuel supply was tagged with an iridium tracer and exposure was monitored during commutes with personal aerosol monitors as a part of an Environmental Justice Project. A total of 68.2 g of Ir as iridium(III)-2,4-pentanedionate were used to induce a concentration of 48.5 μg Ir ℓ -1 of fuel. Twenty samples were collected over 10 days while four students commuted on regularly scheduled buses and a fifth student commuted by private car. Individual samples integrated from 1 to 4 round trips. Iridium analyses were performed instrumentally after neutron activation with a detection limit (DL) of about 500 fg. For students commuting by bus and following protocols, Ir tracer concentrations ranged from 53±38 to >1980±49 fg m -3. Concentrations up to 3530±220 fg m -3 were observed for student #5, who sampled only when boarding and disembarking. Exposure were greatest for students commuting through the heavily trafficked central business district. Corresponding estimates of exposures to soot emitted from municipal buses ranged from ⩽3 to 82 ng soot m -3 (⩽145 ng m -3 for student #5), i.e. well below the exposure level of 2-10 μg m -3 total C from all sources, including the more than 30,000 diesel trucks which pass through the city's major toll facilities each day. Ir was undetectable in samples collected by the student commuting by car when its windows were closed, but comparable to those of the other students when commutes were made with windows open. The Ir tracer DL corresponds to about 21 ng soot, about half of which is carbon. This is far below the 230 ng reported for analysis by a highly sensitive thermal-optical technique.

  12. 26 CFR 1.168(f)(8)-1T - Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 2 2014-04-01 2014-04-01 false Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary). 1.168(f)(8)-1T Section 1.168(f)(8)-1T Internal Revenue... information returns concerning qualified mass commuting vehicles (temporary). In general. Form 6793,...

  13. 26 CFR 1.168(f)(8)-1T - Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 2 2013-04-01 2013-04-01 false Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary). 1.168(f)(8)-1T Section 1.168(f)(8)-1T Internal Revenue... information returns concerning qualified mass commuting vehicles (temporary). In general. Form 6793,...

  14. 26 CFR 1.168(f)(8)-1T - Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 2 2012-04-01 2012-04-01 false Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary). 1.168(f)(8)-1T Section 1.168(f)(8)-1T Internal Revenue... information returns concerning qualified mass commuting vehicles (temporary). In general. Form 6793,...

  15. 26 CFR 1.168(f)(8)-1T - Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary). 1.168(f)(8)-1T Section 1.168(f)(8)-1T Internal Revenue... information returns concerning qualified mass commuting vehicles (temporary). In general. Form 6793,...

  16. 26 CFR 1.168(f)(8)-1T - Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary). 1.168(f)(8)-1T Section 1.168(f)(8)-1T Internal Revenue... information returns concerning qualified mass commuting vehicles (temporary). In general. Form 6793,...

  17. Distribution vacuum-arc fault-current limiter. Final report

    SciTech Connect

    Burrage, L.M.; Pedrow, P.D.; Veverka, E.F.; Landergott, D.R.; Driear, J.M.; Owens, W.R.; Nurmepuu, K.

    1982-02-01

    The objective of this project was the demonstration of the feasibility of using a vacuum arc as the basis for a distribution class fault current limiter. The concept used was an electric discharge in vacuum between a hollow cylindrical anode and a short rod cathode located on the axis of the anode. The device has two modes of operation. One mode utilizes an externally applied axial magnetic field; the other uses the discharge's inherent magnetic field. A series of experiments yielded analytic models of the two modes of operation. It was found that for both cases, high arc voltages were generated by the conduction of current through an electron space charge region (sheath) near the anode. It was concluded that the vacuum arc with applied axial magnetic field was the most suitable mode for use as a commutating switch for a switched resistor fault current limiter. The test device used for the project could reliably commutate currents of 6.4 kA peak. The design of a 20 kA peak prototype commutating switch was completed but the prototype was not constructed. This vacuum arc device with applied axial magnetic field may be considered an alternative switching device for dc applications.

  18. FRW Like Cosmological Model and Accelerated Expansion of the Universe from Non Commutative Seiberg-Witten Geometry

    SciTech Connect

    Aissaoui, H.; Bouhalouf, H.; Mebarki, N.

    2010-10-31

    An FRW like cosmological model in the non commutative Seiberg-Witten space-time is proposed. The pure NCG dynamical apparent horizon and Hawking temperature are obtained and explicit expressions of the scale factor, Hubble and deceleration parameters are derived. The accelerated expansion of the universe scenario is also discussed.

  19. Hispanic First-Generation Commuter Students at a Private College Reflect on Their Experience through the First Year

    ERIC Educational Resources Information Center

    Lurvey, Phyllis C.

    2011-01-01

    A volunteer sample of 16 Hispanic first-generation commuter college students, 9 women and 7 men, 18-30 years of age, attending a private college in the Northeast, were interviewed about their first-year college experience, with an emphasis on issues related to cultural capital and habitus. Five aspects of cultural capital were of interest:…

  20. 41 CFR 302-7.106 - What documentation is required to receive an advance under the commuted rate method?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false What documentation is required to receive an advance under the commuted rate method? 302-7.106 Section 302-7.106 Public Contracts... STORAGE OF PROPERTY 7-TRANSPORTATION AND TEMPORARY STORAGE OF HOUSEHOLD GOODS AND PROFESSIONAL...

  1. 41 CFR 302-7.102 - How is the mileage distance determined under the commuted rate method?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 4 2011-07-01 2011-07-01 false How is the mileage distance determined under the commuted rate method? 302-7.102 Section 302-7.102 Public Contracts and... PROPERTY 7-TRANSPORTATION AND TEMPORARY STORAGE OF HOUSEHOLD GOODS AND PROFESSIONAL BOOKS, PAPERS,...

  2. 41 CFR 302-7.102 - How is the mileage distance determined under the commuted rate method?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false How is the mileage distance determined under the commuted rate method? 302-7.102 Section 302-7.102 Public Contracts and... PROPERTY 7-TRANSPORTATION AND TEMPORARY STORAGE OF HOUSEHOLD GOODS AND PROFESSIONAL BOOKS, PAPERS,...

  3. 41 CFR 302-7.106 - What documentation is required to receive an advance under the commuted rate method?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 4 2011-07-01 2011-07-01 false What documentation is required to receive an advance under the commuted rate method? 302-7.106 Section 302-7.106 Public Contracts... STORAGE OF PROPERTY 7-TRANSPORTATION AND TEMPORARY STORAGE OF HOUSEHOLD GOODS AND PROFESSIONAL...

  4. Changes in Active Commuting to School in Czech Adolescents in Different Types of Built Environment across a 10-Year Period

    PubMed Central

    Dygrýn, Jan; Mitáš, Josef; Gába, Aleš; Rubín, Lukáš; Frömel, Karel

    2015-01-01

    Active commuting (AC) to school represents a great opportunity to incorporate walking or cycling into adolescents’ everyday routine. The objective of the study was to describe changes in AC in Czech adolescents across a 10-year period in different built environments. Data from the 2001 and 2011 Czech Census of Population and Housing were used to examine the mode of transportation taken to school in 6236 adolescents. Changes in AC over time were analyzed for low and high walkable areas separately in two Czech regional cities, Olomouc and Hradec Králové. Between 2001 and 2011, the proportion of adolescents actively commuting to school decreased by 47%, from an absolute rate of 49.1% to 26%. The proportion of active commuters fell in low walkable areas by 61% and in high walkable areas by 39%. The results indicated that adolescents in 2011 were 2.7 times less (OR = 0.365, p < 0.001) likely to actively commute than in 2001. The AC behavior in Czech adolescents has a negative tendency to replicate travel-to-school patterns in adolescents previously described in more developed countries. The findings might serve as a recommendation for municipal policy. PMID:26501304

  5. Potential Effects of a Scenario Earthquake on the Economy of Southern California: Intraregional Commuter, Worker, and Earnings Flow Analysis

    USGS Publications Warehouse

    Sherrouse, Benson C.; Hester, David J.

    2008-01-01

    The Multi-Hazards Demonstration Project (MHDP) is a collaboration between the U.S. Geological Survey (USGS) and various partners from the public and private sectors and academia, meant to improve Southern California's resiliency to natural hazards (Jones and others, 2007). In support of the MHDP objectives, the ShakeOut Scenario was developed. It describes a magnitude 7.8 (M7.8) earthquake along the southernmost 300 kilometers (200 miles) of the San Andreas Fault, identified by geoscientists as a plausible event that will cause moderate to strong shaking over much of the eight-county (Imperial, Kern, Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Ventura) Southern California region (Jones and others, 2008). This report uses selected datasets from the U.S. Census Bureau and the State of California's Employment Development Department to develop preliminary estimates of the number and spatial distribution of commuters who cross the San Andreas Fault and to characterize these commuters by the industries in which they work and their total earnings. The analysis concerns the relative exposure of the region's economy to the effects of the earthquake as described by the location, volume, and earnings of those commuters who work in each of the region's economic sectors. It is anticipated that damage to transportation corridors traversing the fault would lead to at least short-term disruptions in the ability of commuters to travel between their places of residence and work.

  6. Societal Factors; An Analysis of Selected Factors of Dormitory Students and Commuting Students at Johnson and Wales College.

    ERIC Educational Resources Information Center

    Bukowski, Joseph E.

    Focusing on freshmen commuter students and freshmen dormitory students at Johnson and Wales College, general characteristics and academic achievement were measured. General entrance characteristics included student age, College Entrance Examination Board scores and high school rank. Academic achievement was measured in terms of student grades in…

  7. An Examination of Five Benchmarks of Student Engagement for Commuter Students Enrolled at an Urban Public University

    ERIC Educational Resources Information Center

    Galladian, Carol

    2013-01-01

    The purpose of this quantitative ex post facto study was to provide a description of the student engagement of commuter students attending a large urban public university located in a mid-Atlantic state using the five National Survey of Student Engagement (NSSE) benchmarks of student engagement. In addition, the study examined the relationship…

  8. Challenges for Higher Education Couples in Commuter Marriages: Insights for Couples and Counselors Who Work with Them.

    ERIC Educational Resources Information Center

    Magnuson, Sandy; Norem, Ken

    1999-01-01

    Focuses on the experiences of dual-career couples that maintain two homes to attain career satisfaction. Findings include support for the potential strength and satisfaction of commuting relationships. Trust, commitment, regular communication, and quality shared time were endorsed as factors contributing to successful distance marriages.…

  9. 49 CFR 37.49 - Designation of responsible person(s) for intercity and commuter rail stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Designation of responsible person(s) for intercity and commuter rail stations. 37.49 Section 37.49 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities §...

  10. Multichannel commutators of analog signals for measurement of energy distribution over beam cross section of pulse laser

    NASA Astrophysics Data System (ADS)

    Kuznetsov, A. A.

    1984-11-01

    Instruments of measuring the energy distribution over the beam cross section of a pulse laser are checked against standards which include a primary instrument transducer, usually of the magnetic type, in the etalons as well as in reference and operating meters. Measurement of the energy distribution in the case of monopulse lasers with nonreproducible process characteristics and unknown space distributions requires a sufficiently wide dynamic range. The commutator of signals must have a dynamic range of 55 to 65 dB. Existing multichannel commutators of analog signals are inadequate for this application. A comparative design and performance evaluation of special purpose multichannel commutators for this application reveals that electromechanical ones such as ShI relays are superior in terms of low bias voltage with contactors closed, high ratio of open resistance to closed resistance, small temperature drift, wide dynamic range, low crosstalk level, and high stability, while contactless ones such optrons or transistor-diode switches excell in high speed. Accordingly, one or another type of commutator must be selected and design for a given energy distribution measuring instrument, also taking into account the required precision and sensitivity of digital voltmeters used with these instruments.

  11. Ethnic minority children’s active commuting to school and association with physical activity and pedestrian safety behaviors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Children's active commuting to school, i.e. walking or cycling to school, was associated with greater moderate-to-vigorous physical activity, although studies among ethnic minorities are sparse. Among a low-income, ethnic minority sample of fourth grade students from eight public schools, we examine...

  12. 77 FR 34122 - Application of Sun Air Express, LLC, d/b/a Sun Air International for Commuter Authority

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Sun Air Express, LLC, d/b/a Sun Air International for Commuter... to show cause why it should not issue an order finding Sun Air Express, LLC d/b/a Sun...

  13. 14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and...

  14. 14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and...

  15. 14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and...

  16. 14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and...

  17. 14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and...

  18. Active Commuting to School, Weight Status, and Cardiometabolic Risk in Children from Rural Areas: The Cuenca Study

    ERIC Educational Resources Information Center

    Gutiérrez-Zornoza, Myriam; Sánchez-López, Mairena; García-Hermoso, Antonio; González-García, Alberto; Chillón, Palma; Martínez-Vizcaíno, Vicente

    2015-01-01

    Purpose: The aim of this study was to examine (a) whether distance from home to school is a determinant of active commuting to school (ACS), (b) the relationship between distance from home to heavily used facilities (school, green spaces, and sports facilities) and the weight status and cardiometabolic risk categories, and (c) whether ACS has a…

  19. Maximally Localized States in Quantum Mechanics with a Modified Commutation Relation to all Orders

    NASA Astrophysics Data System (ADS)

    Dorsch, Gláuber Carvalho; Nogueira, José Alexandre

    2012-08-01

    We construct the states of maximal localization taking into account a modification of the commutation relation between position and momentum operators to all orders of the minimum length parameter. To first-order, the algebra we use reproduces the one proposed by Kempf, Mangano and Mann. It is emphasized that a minimal length acts as a natural regulator for the theory, thus eliminating the otherwise ever appearing infinities. So, we use our results to calculate the first correction to the Casimir effect due to the minimal length. We also discuss some of the physical consequences of the existence of a minimal length, culminating in a proposal to reformulate the very concept of "position measurement."

  20. A non-perturbative approach to non-commutative scalar field theory

    NASA Astrophysics Data System (ADS)

    Steinacker, Harold

    2005-03-01

    Non-commutative euclidean scalar field theory is shown to have an eigenvalue sector which is dominated by a well-defined eigenvalue density, and can be described by a matrix model. This is established using regularizations of Bbb R2nθ via fuzzy spaces for the free and weakly coupled case, and extends naturally to the non-perturbative domain. It allows to study the renormalization of the effective potential using matrix model techniques, and is closely related to UV/IR mixing. In particular we find a phase transition for the phi4 model at strong coupling, to a phase which is identified with the striped or matrix phase. The method is expected to be applicable in 4 dimensions, where a critical line is found which terminates at a non-trivial point, with nonzero critical coupling. This provides evidence for a non-trivial fixed-point for the 4-dimensional NC phi4 model.

  1. Unpowered Aerodynamic Characteristics of a 15-Percent Scale Model of a Twin-Engine Commuter Aircraft

    NASA Technical Reports Server (NTRS)

    Morgan, D. G.; Galloway, T. L.; Gambucci, B. J.

    1981-01-01

    An experimental investigation was conducted in the Ames 12-Foot Pressure Wind Tunnel to determine the unpowered aerodynamic characteristics of a 15-percent-scale model of a twin-engine commuter aircraft. Model longitudinal aerodynamic characteristics were examined at discrete flap deflections for various angle-of-attack and wind-tunnel-velocity ranges with the empennage on and off. Data are presented for the basic model configuration consisting of the fuselage, wing, basic wing leading edge, double slotted flaps, midengine nacelles, and empennage. Other configurations tested include a particle-span drooped leading edge (dropped outboard of the engine nacelles), a full-span drooped leading edge, low- and high-mounted engine nacelles, and a single-slotted flap. An evaluation was made of the model mounting system by comparing data obtained with the model mounted conventionally on the wind-tunnel model-support struts and the model inverted.

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

    SciTech Connect

    2000-02-28

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

  3. (Ba,Sr)TiO3 tunable capacitors with RF commutation quality factors exceeding 6000

    NASA Astrophysics Data System (ADS)

    Meyers, Cedric J. G.; Freeze, Christopher R.; Stemmer, Susanne; York, Robert A.

    2016-09-01

    The fabrication, measurement, and modeling of radio-frequency (RF), tunable interdigital capacitors (IDCs) are described. High quality factors of 200 in the S/L-bands combined with a 47% tunability are achieved by utilizing epitaxial (Ba,Sr)TiO3 films grown by hybrid molecular beam epitaxy on LaAlO3 substrates. The fabricated devices consisted of one-port and two-port IDCs embedded in ground-signal-ground, coplanar waveguide transmission lines to enable RF probing. Wideband RF scattering parameters under bias were measured from 100 MHz to 40 GHz. A commutation quality factor averaging 6000 across the L band is achieved. These are the highest reported values in this band.

  4. Presentation of Class 1 designs for a family of commuter airplanes

    NASA Technical Reports Server (NTRS)

    Creighton, Tom; Dragush, George; Hendrich, Louis; Hensley, Doug; Morgan, Louise; Oxendine, Charles; Remen, John; Robinson, Terry; Russell, Mark; Swift, Jerry

    1986-01-01

    The Class 1 configuration designs of a family of commuter aircraft are presented. The proposed aircraft will have a capacity of from 25 to 100 passengers. They are to have the following common features: (1) 2 aft fuselage mounted engines; (2) a low wing; (3) a T-tail type empennage; and (4) a tricycle type landing gear. A family concept is introduced to achieve structural, systems and handling quality commonality throughout. Implementing commonality can substantially reduce manufacturing and production costs. By achieving common system designs, maintenance costs can be reduced by permitting airlines to stock a smaller inventory of spares. Therefore, the higher degree of commonality, the lower the direct operating and life cycle costs. The attempt to implement some of the commonality requirements has caused configuration design problems, i.e., the twin-body concept was introduced. Design data are compared to existing aircraft, and the extent of structural, systems and handling qualities achieved are reviewed.

  5. Advanced technology payoffs for future rotorcraft, commuter aircraft, cruise missile, and APU propulsion systems

    NASA Technical Reports Server (NTRS)

    Turk, M. A.; Zeiner, P. K.

    1986-01-01

    In connection with the significant advances made regarding the performance of larger gas turbines, challenges arise concerning the improvement of small gas turbine engines in the 250 to 1000 horsepower range. In response to these challenges, the NASA/Army-sponsored Small Engine Component Technology (SECT) study was undertaken with the objective to identify the engine cycle, configuration, and component technology requirements for the substantial performance improvements desired in year-2000 small gas turbine engines. In the context of this objective, an American turbine engine company evaluated engines for four year-2000 applications, including a rotorcraft, a commuter aircraft, a supersonic cruise missile, and an auxiliary power unit (APU). Attention is given to reference missions, reference engines, reference aircraft, year-2000 technology projections, cycle studies, advanced engine selections, and a technology evaluation.

  6. Efficient, Low-Cost Fan System Research for General Aviation and Commuter Aircraft

    NASA Technical Reports Server (NTRS)

    Merrill, G. L.

    2003-01-01

    This document reports research investigations into efficient, low-cost fan system concepts for high bypass turbofans for future general aviation and commuter aircraft. The research specifically addressed lower pressure ratio fans for good propulsive efficiencies in the 200 to 400 knot flight speed regime. Aerodynamic design analyses yielded predicted efficiency in area of 91 to 92 percent (adiabatic). Low-cost manufacturing studies yielded an aluminum blisk rotor and investment cast stator having lowest cost. Structural design analyses yielded a design having excellent vibratory characteristics and the ability to pass One- and Four-pound bird strikes satisfactorily. The low speed and low pressure fans of the study are estimated to have 24 to 30 EPNdB lower community noise levels than larger, high pressure ratio transonic fans.

  7. Assisting the visually impaired to deal with telephone interview jobs using information and commutation technology.

    PubMed

    Yeh, Fung-Huei; Yang, Chung-Chieh

    2014-12-01

    This study proposed a new information and commutation technology assisted blind telephone interview (ICT-ABTI) system to help visually impaired people to do telephone interview jobs as normal sighted people and create more diverse employment opportunities for them. The study also used an ABAB design to assess the system with seven visually impaired people. As the results, they can accomplish 3070 effective telephone interviews per month independently. The results also show that working performance of the visually impaired can be improved effectively with appropriate design of operation working flow and accessible software. The visually impaired become productive, lucrative, and self-sufficient by using ICT-ABTI system to do telephone interview jobs. The results were also shared through the APEC Digital Opportunity Center platform to help visually impaired in Philippines, Malaysia and China. PMID:25209925

  8. Average-Case Complexity Versus Approximate Simulation of Commuting Quantum Computations

    NASA Astrophysics Data System (ADS)

    Bremner, Michael J.; Montanaro, Ashley; Shepherd, Dan J.

    2016-08-01

    We use the class of commuting quantum computations known as IQP (instantaneous quantum polynomial time) to strengthen the conjecture that quantum computers are hard to simulate classically. We show that, if either of two plausible average-case hardness conjectures holds, then IQP computations are hard to simulate classically up to constant additive error. One conjecture relates to the hardness of estimating the complex-temperature partition function for random instances of the Ising model; the other concerns approximating the number of zeroes of random low-degree polynomials. We observe that both conjectures can be shown to be valid in the setting of worst-case complexity. We arrive at these conjectures by deriving spin-based generalizations of the boson sampling problem that avoid the so-called permanent anticoncentration conjecture.

  9. Average-Case Complexity Versus Approximate Simulation of Commuting Quantum Computations.

    PubMed

    Bremner, Michael J; Montanaro, Ashley; Shepherd, Dan J

    2016-08-19

    We use the class of commuting quantum computations known as IQP (instantaneous quantum polynomial time) to strengthen the conjecture that quantum computers are hard to simulate classically. We show that, if either of two plausible average-case hardness conjectures holds, then IQP computations are hard to simulate classically up to constant additive error. One conjecture relates to the hardness of estimating the complex-temperature partition function for random instances of the Ising model; the other concerns approximating the number of zeroes of random low-degree polynomials. We observe that both conjectures can be shown to be valid in the setting of worst-case complexity. We arrive at these conjectures by deriving spin-based generalizations of the boson sampling problem that avoid the so-called permanent anticoncentration conjecture. PMID:27588839

  10. A review of commuter exposure to ultrafine particles and its health effects

    NASA Astrophysics Data System (ADS)

    Knibbs, Luke D.; Cole-Hunter, Tom; Morawska, Lidia

    2011-05-01

    Ultrafine particles (UFPs, <100 nm) are produced in large quantities by vehicular combustion and are implicated in causing several adverse human health effects. Recent work has suggested that a large proportion of daily UFP exposure may occur during commuting. However, the determinants, variability and transport mode-dependence of such exposure are not well-understood. The aim of this review was to address these knowledge gaps by distilling the results of 'in-transit' UFP exposure studies performed to-date, including studies of health effects. We identified 47 exposure studies performed across 6 transport modes: automobile, bicycle, bus, ferry, rail and walking. These encompassed approximately 3000 individual trips where UFP concentrations were measured. After weighting mean UFP concentrations by the number of trips in which they were collected, we found overall mean UFP concentrations of 3.4, 4.2, 4.5, 4.7, 4.9 and 5.7 × 10 4 particles cm -3 for the bicycle, bus, automobile, rail, walking and ferry modes, respectively. The mean concentration inside automobiles travelling through tunnels was 3.0 × 10 5 particles cm -3. While the mean concentrations were indicative of general trends, we found that the determinants of exposure (meteorology, traffic parameters, route, fuel type, exhaust treatment technologies, cabin ventilation, filtration, deposition, UFP penetration) exhibited marked variability and mode-dependence, such that it is not necessarily appropriate to rank modes in order of exposure without detailed consideration of these factors. Ten in-transit health effects studies have been conducted and their results indicate that UFP exposure during commuting can elicit acute effects in both healthy and health-compromised individuals. We suggest that future work should focus on further defining the contribution of in-transit UFP exposure to total UFP exposure, exploring its specific health effects and investigating exposures in the developing world.

  11. Naturalistic Cycling Study: Identifying Risk Factors for On-Road Commuter Cyclists

    PubMed Central

    Johnson, Marilyn; Charlton, Judith; Oxley, Jennifer; Newstead, Stuart

    2010-01-01

    The study aim was to identify risk factors for collisions/near-collisions involving on-road commuter cyclists and drivers. A naturalistic cycling study was conducted in Melbourne, Australia, with cyclists wearing helmet-mounted video cameras. Video recordings captured cyclists’ perspective of the road and traffic behaviours including head checks, reactions and manoeuvres. The 100-car naturalistic driving study analysis technique was adapted for data analysis and events were classified by severity: collision, near-collision and incident. Participants were adult cyclists and each filmed 12 hours of commuter cycling trips over a 4-week period. In total, 127 hours and 38 minutes were analysed for 13 participants, 54 events were identified: 2 collisions, 6 near-collisions and 46 incidents. Prior to events, 88.9% of cyclists travelled in a safe/legal manner. Sideswipe was the most frequent event type (40.7%). Most events occurred at an intersection/intersection-related location (70.3%). The vehicle driver was judged at fault in the majority of events (87.0%) and no post-event driver reaction was observed (83.3%). Cross tabulations revealed significant associations between event severity and: cyclist reaction, cyclist post-event manoeuvre, pre-event driver behaviour, other vehicle involved, driver reaction, visual obstruction, cyclist head check (left), event type and vehicle location (p<0.05). Frequent head checks suggest cyclists had high situational awareness and their reactive behaviour to driver actions led to successful avoidance of collisions/near-collisions. Strategies to improve driver awareness of on-road cyclists and to indicate early before turning/changing lanes when sharing the roadway with cyclists are discussed. Findings will contribute to the development of effective countermeasures to reduce cyclist trauma. PMID:21050610

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

    PubMed

    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 (N<2.5×10(4) part. cm(-3)), higher during tram travel and suburban walking (2.5×10(4) cm(-3)5.0×10(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 (<70 nm), and concentrations of fine particulate matter (PM2.5) and Black Carbon are lower in the tram when compared to both bus and subway. CO2 levels in public transport reflect passenger numbers, more than tripling from outdoor levels to >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. PMID:26277386

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

    PubMed

    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 (N<2.5×10(4) part. cm(-3)), higher during tram travel and suburban walking (2.5×10(4) cm(-3)5.0×10(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 (<70 nm), and concentrations of fine particulate matter (PM2.5) and Black Carbon are lower in the tram when compared to both bus and subway. CO2 levels in public transport reflect passenger numbers, more than tripling from outdoor levels to >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.

  14. Perceived barriers to children's active commuting to school: a systematic review of empirical, methodological and theoretical evidence.

    PubMed

    Lu, Wenhua; McKyer, E Lisako J; Lee, Chanam; Goodson, Patricia; Ory, Marcia G; Wang, Suojin

    2014-11-18

    Active commuting to school (ACS) may increase children's daily physical activity and help them maintain a healthy weight. Previous studies have identified various perceived barriers related to children's ACS. However, it is not clear whether and how these studies were methodologically sound and theoretically grounded. The purpose of this review was to critically assess the current literature on perceived barriers to children's ACS and provide recommendations for future studies. Empirically based literature on perceived barriers to ACS was systematically searched from six databases. A methodological quality scale (MQS) and a theory utilization quality scale (TQS) were created based on previously established instruments and tailored for the current review. Among the 39 studies that met the inclusion criteria, 19 (48.7%) reported statistically significant perceived barriers to child's ACS. The methodological and theory utilization qualities of reviewed studies varied, with MQS scores ranging between 7 and 20 (Mean =12.95, SD =2.95) and TQS scores from 1 to 7 (Mean =3.62, SD =1.74). A detailed appraisal of the literature suggests several empirical, methodological, and theoretical recommendations for future studies on perceived barriers to ACS. Empirically, increasing the diversity of study regions and samples should be a high priority, particularly in Asian and European countries, and among rural residents; more prospective and interventions studies are needed to determine the causal mechanism liking the perceived factors and ACS; future researchers should include policy-related barriers into their inquiries. Methodologically, the conceptualization of ACS should be standardized or at least well rationalized in future studies to ensure the comparability of results; researchers' awareness need to be increased for improving the methodological rigor of studies, especially in regard to appropriate statistical analysis techniques, control variable estimation

  15. Eddy current loss and coil inductance evaluation in DC machines by a PG-based F. E. Code

    SciTech Connect

    Arturi, C.M.; Ubaldini, M. )

    1991-09-01

    The present paper deals with the evaluation of both the eddy current loss and the self and mutual inductances of the commutating coils of a dc machine armature-winding for railway traction by a two-dimension PC-based finite element commercial code. The comparison among several distribution of the conductors occupying a given slot and among slots with different ratio of depth to width is made in this paper in order to determine, for a given dc machine, the best design solution with references to both the loss and the self and mutual inductances of the commutating coils.

  16. Personal exposure to black carbon during commuting in peak and off-peak hours in Shanghai.

    PubMed

    Li, Bo; Lei, Xiao-ning; Xiu, Guang-li; Gao, Chi-yuan; Gao, Shuang; Qian, Ni-sheng

    2015-08-15

    A study on a commuter's exposure to black carbon (BC) in five different traffic modes (taxi, bus, subway, cycling and walking) was conducted in Xuhui District, Shanghai. A commuter's real-time exposure concentrations were recorded by MicroAeth AE51 BC monitors, and the average BC exposure concentration and inhalation dose were analyzed. Data collected by cyclist was applied to characterize the micro-variability in relation to traffic density and street topology. The distance to the traffic and the street topology as well as the volume of heavy diesel trucks were the dominant factors influencing the BC concentrations. In this study, a high variability of BC concentrations between streets and even within streets was observed, and also between days and hour of the day. The average BC exposure concentrations were 5.59±1.02 μg/m(3), 6.58±1.78 μg/m(3), 7.28±1.87 μg/m(3), 8.62±4.13 μg/m(3) and 9.43±2.89 μg/m(3) for walking, cycling, bus, taxi and subway trips, respectively. Exposure levels of in-vehicle microenvironments were 8.66±3.66 μg/m(3), 9.39±6.98 μg/m(3) and 10.96±2.72 μg/m(3) for bus, taxi and subway, respectively. While inhalation doses were 0.68±0.33 μg, 0.95±0.29 μg, 1.36±0.37 μg, 1.50±0.39 μg and 1.58±0.29 μg for taxi, subway, cycling, bus and walking, respectively. BC exposure level of walking was the lowest among all the traffic modes, but its inhalation dose was the highest. PMID:25909267

  17. Leisure-time exercise, physical activity during work and commuting, and risk of metabolic syndrome.

    PubMed

    Kuwahara, Keisuke; Honda, Toru; Nakagawa, Tohru; Yamamoto, Shuichiro; Akter, Shamima; Hayashi, Takeshi; Mizoue, Tetsuya

    2016-09-01

    Data are limited regarding effect of intensity of leisure-time physical activity on metabolic syndrome. Furthermore, no prospective data are available regarding effect of occupational and commuting physical activity on metabolic syndrome. We compared metabolic syndrome risk by intensity level of leisure-time exercise and by occupational and commuting physical activity in Japanese workers. We followed 22,383 participants, aged 30-64 years, without metabolic syndrome until 2014 March (maximum, 5 years of follow-up). Physical activity was self-reported. Metabolic syndrome was defined by the Joint Statement criteria. We used Cox regression models to estimate the hazard ratios (HRs) and 95 % confidence intervals (CIs) of metabolic syndrome. During a mean follow-up of 4.1 years, 5361 workers developed metabolic syndrome. After adjustment for covariates, compared with engaging in no exercise, the HRs (95 % CIs) for <7.5, 7.5 to <16.5, and ≥16.5 metabolic equivalent hours of exercise per week were 0.99 (0.90, 1.08), 0.99 (0.90, 1.10), and 0.95 (0.83, 1.08), respectively, among individuals engaging in moderate-intensity exercise alone; 0.93 (0.75, 1.14), 0.81 (0.64, 1.02), and 0.84 (0.66, 1.06), among individuals engaging in vigorous-intensity exercise alone; and 0.90 (0.70, 1.17), 0.74 (0.62, 0.89), and 0.81 (0.69, 0.96) among individuals engaging in the two intensities. Higher occupational physical activity was weakly but significantly associated with lower risk of metabolic syndrome. Walking to and from work was not associated with metabolic syndrome. Vigorous-intensity exercise alone or vigorous-intensity combined with moderate-intensity exercise and worksite intervention for physical activity may help prevent metabolic syndrome for Japanese workers.

  18. Personal exposure to benzene of selected population groups and impact of commuting modes in Ho Chi Minh, Vietnam.

    PubMed

    Lan, Tran Thi Ngoc; Liem, Ngo Quang; Binh, Nguyen Thi Thanh

    2013-04-01

    Personal exposure to benzene of selected population groups, and impacts of traffic on commuters in Ho Chi Minh City were investigated. The study was carried out in June, July and November 2010. The preliminary data showed that on average, personal exposure to benzene for non-occupational people in Ho Chi Minh is ~18 μg/m(3) and most of the exposure is due to commuting. Benzene exposure during travelling by bus, taxi and motorcycle is, respectively, 22-30, 22-39 and 185-240 μg/m(3). Motorcycle-taxi drivers, petrol filling employees and street vendors suffer high daily exposures at 116, 52, 32 μg/m(3), respectively. Further measurements are needed for a better risk assessment and finding effective measures to reduce exposure.

  19. The research of the solar panels-commutator-inverter-load system with the pulse-amplitude control

    NASA Astrophysics Data System (ADS)

    Taissariyeva, K. N.; Issembergenov, N. T.

    2014-11-01

    The system "solar panels-commutator-inverter-load" with amplitude-impulse control was researched. It was shown that if the solar panels are located in a certain way at the input of the inverter, it will be possible to get multilevel voltage close to sine wave with the help of amplitude-impulse control of commutator at the output of inverter. Herewith the effect is saving of solar panels depending on the quantity of voltage level, and also the enhanced voltage distortion coefficient (THD). For instance, with 8-level of voltage 28,2% and THD=4,64%, with 13-level of voltage, 30,5% and THD=2,65%, and with 26-level of voltage 31,7% and THD=1,22%. The given results were obtained through computer modeling and experimental research.

  20. Discrete spin structures and commuting projector models for two-dimensional fermionic symmetry-protected topological phases

    NASA Astrophysics Data System (ADS)

    Tarantino, Nicolas; Fidkowski, Lukasz

    2016-09-01

    We construct exactly solved commuting projector Hamiltonian lattice models for all known (2+1)-dimensional (2+1D) fermionic symmetry protected topological phases (SPTs) with on-site unitary symmetry group Gf=G ×Z2f , where G is finite and Z2f is the fermion parity symmetry. In particular, our models transcend the class of group supercohomology models, which realize some, but not all, fermionic SPTs in 2+1D. A natural ingredient in our construction is a discrete form of the spin structure of the 2D spatial surface M on which our model is defined, namely a "Kasteleyn" orientation of a certain graph associated with the lattice. As a special case, our construction yields commuting projector models for all eight members of the Z8 classification of 2D fermionic SPTs with G =Z2 .

  1. Meixner Class of Non-commutative Generalized Stochastic Processes with Freely Independent Values II. The Generating Function

    NASA Astrophysics Data System (ADS)

    Bożejko, Marek; Lytvynov, Eugene

    2011-03-01

    Let T be an underlying space with a non-atomic measure σ on it. In [ Comm. Math. Phys. 292, 99-129 (2009)] the Meixner class of non-commutative generalized stochastic processes with freely independent values, {ω=(ω(t))_{tin T}} , was characterized through the continuity of the corresponding orthogonal polynomials. In this paper, we derive a generating function for these orthogonal polynomials. The first question we have to answer is: What should serve as a generating function for a system of polynomials of infinitely many non-commuting variables? We construct a class of operator-valued functions {Z=(Z(t))_{tin T}} such that Z( t) commutes with ω( s) for any {s,tin T}. Then a generating function can be understood as {G(Z,ω)=sum_{n=0}^infty int_{T^n}P^{(n)}(ω(t_1),dots,ω(t_n))Z(t_1)dots Z(t_n)} {σ(dt_1) dots σ(dt_n)} , where {P^{(n)}(ω(t_1),dots,ω(t_n))} is (the kernel of the) n th orthogonal polynomial. We derive an explicit form of G( Z, ω), which has a resolvent form and resembles the generating function in the classical case, albeit it involves integrals of non-commuting operators. We finally discuss a related problem of the action of the annihilation operators {partial_t,t in T} . In contrast to the classical case, we prove that the operators ∂ t related to the free Gaussian and Poisson processes have a property of globality. This result is genuinely infinite-dimensional, since in one dimension one loses the notion of globality.

  2. Presentation of flight control design and handling quality commonality by separate surface stability augmentation for the family of commuter airplanes

    NASA Technical Reports Server (NTRS)

    Hensley, Douglas; Creighton, Thomas; Haddad, Raphael; Hendrich, Louis; Morgan, Louise; Russell, Mark; Swift, Gerald

    1987-01-01

    The methodology and results for a flight control design and implementation for common handling qualities by Separate Surface Stability Augmentation (SSSA) for the family of commuter airplanes are contained. The open and closed loop dynamics and the design results of augmenting for common handling qualities are presented. The physical and technology requirements are presented for implementing the SSSA system. The conclusion of this report and recommendations for changes or improvement are discussed.

  3. Exposure of commuters to carbon monoxide in Mexico City II. Comparison of in-vehicle and fixed-site concentrations.

    PubMed

    Fernandez-Bremauntz, A A; Ashmore, M R

    1995-01-01

    The objective of this paper is to compare measurements of carbon monoxide taken concurrently inside vehicles and at fixed-site monitoring stations (FSMs), in order to assess if the FSM stations can be used to estimate commuters' exposure to this pollutant. During the study period ambient CO concentrations were very high. Five selected stations reported concentrations in excess of the Mexican (13 ppm) and United States (9 ppm) 8-hour standards for CO. Since, for all modes of transportation, the in-vehicle concentrations were always larger than the concurrent ambient concentrations, the differences between them were always positive and the ratios were always greater than one. Average, in-vehicle/ambient ratios for each mode of transportation were: automobile, 5.2; minivan, 5.2; minibus, 4.3; bus, 3.1; trolleybus 3.0; and metro, 2.2. A series of simple regression models with a moderate predictive power (R2 = 0.47 to 0.71) were developed for metro, bus, minibus, and automobile commuters. The models include the FSM measurements and also, depending on the mode of transportation, other variables, such as vehicular speed, the route of travel, and the wind speed. In the future, the models should be validated in two ways to determine their predictive power. First, they should be verified against additional samples taken under similar conditions; and second, their applications under different conditions should be explored through sampling during a different season of the year or on other commuting routes.

  4. Local commutativity versus Bell inequality violation for entangled states and versus non-violation for separable states

    SciTech Connect

    Seevinck, Michael; Uffink, Jos

    2007-10-15

    By introducing a quantitative 'degree of commutativity' in terms of the angle between spin observables we present two tight quantitative trade-off relations in the case of two qubits. First, for entangled states, between the degree of commutativity of local observables and the maximal amount of violation of the Bell inequality: if both local angles increase from zero to {pi}/2 (i.e., the degree of local commutativity decreases), the maximum violation of the Bell inequality increases. Secondly, a converse trade-off relation holds for separable states: if both local angles approach {pi}/2 the maximal value obtainable for the correlations in the Bell inequality decreases and thus the non-violation increases. As expected, the extremes of these relations are found in the case of anticommuting local observables where, respectively, the bounds of 2{radical}(2) and {radical}(2) hold for the expectation value of the Bell operator. The trade-off relations show that noncommmutativity gives 'a more than classical result' for entangled states, whereas 'a less than classical result' is obtained for separable states. The experimental relevance of the trade-off relation for separable states is that it provides an experimental test for two qubit entanglement. Its advantages are twofold: in comparison to violations of Bell inequalities it is a stronger criterion and in comparison to entanglement witnesses it needs to make less strong assumptions about the observables implemented in the experiment.

  5. Rethinking Connes' approach to the standard model of particle physics via non-commutative geometry

    NASA Astrophysics Data System (ADS)

    Boyle, Latham; Farnsworth, Shane

    2015-04-01

    Connes' non-commutative geometry (NCG) is a generalization of Riemannian geometry that is particularly apt for expressing the standard model of particle physics coupled to Einstein gravity. Recently, we suggested a reformulation of this framework that is: (i) simpler and more unified in its axioms, and (ii) allows the Lagrangian for the standard model of particle physics (coupled to Einstein gravity) to be specified in a way that is tighter and more explanatory than the traditional algorithm based on effective field theory. Here we explain how this same reformulation yields a new perspective on the symmetries of a given NCG. Applying this perspective to the NCG traditionally used to describe the standard model we find, instead, an extension of the standard model by an extra U(1) B - L gauge symmetry, and a single extra complex scalar field σ, which is a singlet under SU(3)C × SU(2)L × U(1)Y , but has B - L = 2 . This field has cosmological implications, and offers a new solution to the discrepancy between the observed Higgs mass and the NCG prediction. We acknowledge support from an NSERC Discovery Grant.

  6. Rethinking Connes’ Approach to the Standard Model of Particle Physics Via Non-Commutative Geometry

    NASA Astrophysics Data System (ADS)

    Farnsworth, Shane; Boyle, Latham

    2015-02-01

    Connes’ non-commutative geometry (NCG) is a generalization of Riemannian geometry that is particularly apt for expressing the standard model of particle physics coupled to Einstein gravity. In a previous paper, we suggested a reformulation of this framework that is: (i) simpler and more unified in its axioms, and (ii) allows the Lagrangian for the standard model of particle physics (coupled to Einstein gravity) to be specified in a way that is tighter and more explanatory than the traditional algorithm based on effective field theory. Here we explain how this same reformulation yields a new perspective on the symmetries of a given NCG. Applying this perspective to the NCG traditionally used to describe the standard model we find, instead, an extension of the standard model by an extra U{{(1)}B-L} gauge symmetry, and a single extra complex scalar field σ, which is a singlet under SU{{(3)}C}× SU{{(2)}L}× U{{(1)}Y}, but has B-L=2. This field has cosmological implications, and offers a new solution to the discrepancy between the observed Higgs mass and the NCG prediction.

  7. On Generating Discrete Integrable Systems via Lie Algebras and Commutator Equations

    NASA Astrophysics Data System (ADS)

    Zhang, Yu-Feng; Tam, Honwah

    2016-03-01

    In the paper, we introduce the Lie algebras and the commutator equations to rewrite the Tu-d scheme for generating discrete integrable systems regularly. By the approach the various loop algebras of the Lie algebra A1 are defined so that the well-known Toda hierarchy and a novel discrete integrable system are obtained, respectively. A reduction of the later hierarchy is just right the famous Ablowitz–Ladik hierarchy. Finally, via two different enlarging Lie algebras of the Lie algebra A1, we derive two resulting differential-difference integrable couplings of the Toda hierarchy, of course, they are all various discrete expanding integrable models of the Toda hierarchy. When the introduced spectral matrices are higher degrees, the way presented in the paper is more convenient to generate discrete integrable equations than the Tu-d scheme by using the software Maple. Supported by the National Natural Science Foundation of China under Grant No. 11371361, the Innovation Team of Jiangsu Province hosted by China University of Mining and Technology (2014), and Hong Kong Research Grant Council under Grant No. HKBU202512, as well as the Natural Science Foundation of Shandong Province under Grant No. ZR2013AL016

  8. On Generating Discrete Integrable Systems via Lie Algebras and Commutator Equations

    NASA Astrophysics Data System (ADS)

    Zhang, Yu-Feng; Tam, Honwah

    2016-03-01

    In the paper, we introduce the Lie algebras and the commutator equations to rewrite the Tu-d scheme for generating discrete integrable systems regularly. By the approach the various loop algebras of the Lie algebra A1 are defined so that the well-known Toda hierarchy and a novel discrete integrable system are obtained, respectively. A reduction of the later hierarchy is just right the famous Ablowitz-Ladik hierarchy. Finally, via two different enlarging Lie algebras of the Lie algebra A1, we derive two resulting differential-difference integrable couplings of the Toda hierarchy, of course, they are all various discrete expanding integrable models of the Toda hierarchy. When the introduced spectral matrices are higher degrees, the way presented in the paper is more convenient to generate discrete integrable equations than the Tu-d scheme by using the software Maple. Supported by the National Natural Science Foundation of China under Grant No. 11371361, the Innovation Team of Jiangsu Province hosted by China University of Mining and Technology (2014), and Hong Kong Research Grant Council under Grant No. HKBU202512, as well as the Natural Science Foundation of Shandong Province under Grant No. ZR2013AL016

  9. Improved transistor-controlled and commutated brushless DC motors for electric vehicle propulsion

    NASA Technical Reports Server (NTRS)

    Demerdash, N. A.; Miller, R. H.; Nehl, T. W.; Nyamusa, T. A.

    1983-01-01

    The development, design, construction, and testing processes of two electronically (transistor) controlled and commutated permanent magnet brushless dc machine systems, for propulsion of electric vehicles are detailed. One machine system was designed and constructed using samarium cobalt for permanent magnets, which supply the rotor (field) excitation. Meanwhile, the other machine system was designed and constructed with strontium ferrite permanent magnets as the source of rotor (field) excitation. These machine systems were designed for continuous rated power output of 15 hp (11.2 kw), and a peak one minute rated power output of 35 hp (26.1 kw). Both power ratings are for a rated voltage of 115 volts dc, assuming a voltage drop in the source (battery) of about 5 volts. That is, an internal source voltage of 120 volts dc. Machine-power conditioner system computer-aided simulations were used extensively in the design process. These simulations relied heavily on the magnetic field analysis in these machines using the method of finite elements, as well as methods of modeling of the machine power conditioner system dynamic interaction. These simulation processes are detailed. Testing revealed that typical machine system efficiencies at 15 hp (11.2 kw) were about 88% and 84% for the samarium cobalt and strontium ferrite based machine systems, respectively. Both systems met the peak one minute rating of 35 hp.

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

    NASA Technical Reports Server (NTRS)

    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.

  11. Fast katz and commuters : efficient estimation of social relatedness in large networks.

    SciTech Connect

    On, Byung-Won; Lakshmanan, Laks V. S.; Greif, Chen; Esfandiar, Pooya; Bonchi, Francesco; Gleich, David F.

    2010-09-01

    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.

  12. Detailed design of a Ride Quality Augmentation System for commuter aircraft

    NASA Technical Reports Server (NTRS)

    Suikat, Reiner; Donaldson, Kent E.; Downing, David R.

    1989-01-01

    The design of a Ride Quality Augmentation System (RQAS) for commuter aircraft is documented. The RQAS is designed for a Cessna 402B, an 8 passenger prop twin representative to this class of aircraft. The purpose of the RQAS is the reduction of vertical and lateral accelerations of the aircraft due to atmospheric turbulence by the application of active control. The detailed design of the hardware (the aircraft modifications, the Ride Quality Instrumentation System (RQIS), and the required computer software) is examined. The aircraft modifications, consisting of the dedicated control surfaces and the hydraulic actuation system, were designed at Cessna Aircraft by Kansas University-Flight Research Laboratory. The instrumentation system, which consist of the sensor package, the flight computer, a Data Acquisition System, and the pilot and test engineer control panels, was designed by NASA-Langley. The overall system design and the design of the software, both for flight control algorithms and ground system checkout are detailed. The system performance is predicted from linear simulation results and from power spectral densities of the aircraft response to a Dryden gust. The results indicate that both accelerations are possible.

  13. Adaptive vibration control using synchronous demodulation with machine tool controller motor commutation

    DOEpatents

    Hopkins, David James

    2008-05-13

    A control system and method for actively reducing vibration in a spindle housing caused by unbalance forces on a rotating spindle, by measuring the force-induced spindle-housing motion, determining control signals based on synchronous demodulation, and provide compensation for the measured displacement to cancel or otherwise reduce or attenuate the vibration. In particular, the synchronous demodulation technique is performed to recover a measured spindle housing displacement signal related only to the rotation of a machine tool spindle, and consequently rejects measured displacement not related to spindle motion or synchronous to a cycle of revolution. Furthermore, the controller actuates at least one voice-coil (VC) motor, to cancel the original force-induced motion, and adapts the magnitude of voice coil signal until this measured displacement signal is brought to a null. In order to adjust the signal to a null, it must have the correct phase relative to the spindle angle. The feedback phase signal is used to adjust a common (to both outputs) commutation offset register (offset relative to spindle encoder angle) to force the feedback phase signal output to a null. Once both of these feedback signals are null, the system is compensating properly for the spindle-induced motion.

  14. Fast Katz and Commuters: Efficient Estimation of Social Relatedness in Large Networks

    NASA Astrophysics Data System (ADS)

    Esfandiar, Pooya; Bonchi, Francesco; Gleich, David F.; Greif, Chen; Lakshmanan, Laks V. S.; On, Byung-Won

    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.

  15. Effects of residential relocation on household and commuting expenditures in Shanghai, China.

    PubMed

    Day, Jennifer; Cervero, Robert

    2010-01-01

    Over the past three decades, China's cities have undergone massive spatial restructuring in the wake of market reforms and economic growth. One consequence has been a rapid migration of urban residents to the periphery. Some movers have been forced out either by rising urban rents or government reclamation of their residences. Others have relocated willingly to modernized housing or for other lifestyle reasons. This article examines the effects of relocation to the urban edge on household well-being. It explores the factors underlying changes in housing and transportation costs as households move to the periphery. The research also examines whether those who moved involuntarily are affected differently from those who moved by choice. Results show that, relative to those who moved by choice, involuntary movers are disproportionately and adversely affected in terms of job accessibility, commute time, housing consumption and disposable income. The findings also show that, compared with higher-income households, lower-income groups are disproportionately affected in relation to housing costs, accessibility losses, disposable income and household worker composition. These results indicate that relocation compensation for involuntarily relocated households should be expanded to include more than just housing value: it should encompass urban location changes, household needs and relocation costs. PMID:21132950

  16. Indirect determination of aflatoxin B₁ in beer via a multi-commuted optical sensor.

    PubMed

    Molina-García, Lucía; Fernández-de Córdova, Maria Luisa; Ruiz-Medina, Antonio

    2012-01-01

    This paper reports the determination of aflatoxin B₁ (AFB₁), one of the most carcinogenic substances known. A multi-commuted flow injection-solid phase spectroscopy (FI-SPS) system combined with photochemically induced fluorescence (PIF) was developed, for the first time, for its quantitative determination. A strongly fluorescent degradation product was obtained on-line by irradiation with ultraviolet light. The determination was carried out by measuring the fluorescence intensity of the photo-product at 353/424 (λ (ex)/λ (em)), once retained on C₁₈ silica-gel filling the flow-cell. A linear dynamic range of 0.09-12 µg l⁻¹, detection limit as sensitive as 29 ng l⁻¹ and a relative standard deviation (RSD) of 1.4% were obtained. The method proposed was satisfactorily applied to the determination of AFB₁ in different types of beer (normal and non-alcoholic). Hydrophobic compounds were eliminated from beer samples and AFB₁ was extracted with acetonitrile by solid-phase extraction on C₁₈ sorbent. Recoveries of the target compound from spiked beers were between 94 and 106%. The results obtained in the analysis of real samples are in good agreement with those provided by a reference chromatographic method.

  17. Spatial interaction models from Irish commuting data: variations in trip length by occupation and gender

    NASA Astrophysics Data System (ADS)

    O'Kelly, Morton E.; Niedzielski, Michael A.; Gleeson, Justin

    2012-10-01

    Core and peripheral contrasts in journey-to-work trip length can be interpreted as imputing the relative value of origin and destination accessibility (yielding theoretical proxies for rent and wages). Because the main variables are shown to be critically dependent on spatial structure, they may be interpreted as showing the shadow prices due to comparative location. There is also a unifying connection between these results and the existing literature on many dimensions: rent gradients, accessibility, and emissivity. In an empirical example, the advantages of a panoramic view of national commuting statistics are shown, using an Irish data set. Variations in the rates of participation in trip making by location, occupation, and gender are examined. Places that emit more trips than would be expected from their relative location are identified. Further, examining ways in which such emissivity is sensitive to a change in trip length highlights the regions where trips could possibly be adjusted to produce a shorter average trip length or which might be especially sensitive to reduction in employment. A careful reinterpretation of one of the key outputs from a calibrated spatial interaction model is shown to be consistent with the declining rent gradient expected from Alonso's theory of land use.

  18. Weak commutation relations and eigenvalue statistics for products of rectangular random matrices.

    PubMed

    Ipsen, Jesper R; Kieburg, Mario

    2014-03-01

    We study the joint probability density of the eigenvalues of a product of rectangular real, complex, or quaternion random matrices in a unified way. The random matrices are distributed according to arbitrary probability densities, whose only restriction is the invariance under left and right multiplication by orthogonal, unitary, or unitary symplectic matrices, respectively. We show that a product of rectangular matrices is statistically equivalent to a product of square matrices. Hereby we prove a weak commutation relation of the random matrices at finite matrix sizes, which previously has been discussed for infinite matrix size. Moreover, we derive the joint probability densities of the eigenvalues. To illustrate our results, we apply them to a product of random matrices drawn from Ginibre ensembles and Jacobi ensembles as well as a mixed version thereof. For these weights, we show that the product of complex random matrices yields a determinantal point process, while the real and quaternion matrix ensembles correspond to Pfaffian point processes. Our results are visualized by numerical simulations. Furthermore, we present an application to a transport on a closed, disordered chain coupled to a particle bath. PMID:24730789

  19. Symmetries and conservation laws of space-times admitting two commuting killing vectors

    NASA Astrophysics Data System (ADS)

    Menon, Balraj

    In this dissertation, we determined all first-order generalized symmetries of the vacuum Einstein equations for spacetimes admitting two commuting Killing vector fields. The field equations for the two Killing vector models, referred to as the reduced Einstein equations, were first derived using a projection formalism first developed by Geroch. In the derivation of the reduced Einstein equations, we assumed the two-dimensional distribution orthogonal to the vector spaces spanned by the Killing vector fields admits integral submanifolds. Prior to embarking on the symmetry analysis, the reduced Einstein equations were expressed in harmonic-null coordinates. A brief survey of the theory of symmetry groups of differential equations, variational symmetries, and local conservation laws preceded the generalized symmetry analysis of the reduced Einstein equation. These concepts were motivated and presented through their application to a variety of physical systems drawn from classical mechanics, quantum mechanics, classical electromagnetism, and general relativity. We obtained partial results from a preliminary analysis of kth-order generalized symmetries (for k ≥ 1) of the reduced Einstein equations. This was followed by the determination of all first-order generalized symmetries admitted by the reduced Einstein equations. We showed that all first-order generalized symmetries of the reduced Einstein equations are, in fact, prolonged point symmetries. Since the reduced Einstein equations admit a Lagrangian formulation, the variational symmetries and local conservation laws associated with the first-order symmetries were also determined and discussed.

  20. Crash Simulation of a Vertical Drop Test of a Commuter-Class Aircraft

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L.

    2004-01-01

    A finite element model of an ATR42-300 commuter-class aircraft was developed and a crash simulation was executed. Analytical predictions were correlated with data obtained from a 30-ft/s (9.14-m/s) vertical drop test of the aircraft. The purpose of the test was to evaluate the structural response of the aircraft when subjected to a severe, but survivable, impact. The aircraft was configured with seats, dummies, luggage, and other ballast. The wings were filled with 8,700 lb. (3,946 kg) of water to represent the fuel. The finite element model, which consisted of 57,643 nodes and 62,979 elements, was developed from direct measurements of the airframe geometry. The seats, dummies, luggage, fuel, and other ballast were represented using concentrated masses. The model was executed in LS-DYNA, a commercial code for performing explicit transient dynamic simulations. Predictions of structural deformation and selected time-history responses were generated. The simulation was successfully validated through extensive test-analysis correlation.

  1. Application Study of a High Temperature Superconducting Fault Current Limiter for Electric Power System

    NASA Astrophysics Data System (ADS)

    Naito, Yuji; Shimizu, Iwao; Yamaguchi, Iwao; Kaiho, Katsuyuki; Yanabu, Satoru

    Using high temperature superconductor, a Superconducting Fault Current Limiter (SFCL) was made and tested. Superconductor and vacuum interrupter as commutation switch are connected in parallel with bypass coil. When a fault occurs and the excessive current flows, superconductor is first quenched and the current is transferred to bypass coil because on voltage drop of superconductor. At the same time, since magnetic field is generated by current which flows in bypass coil, commutation switch is immediately driven by electromagnetic repulsion plate connected to driving rod of vacuum interrupter, and superconductor is separated from this circuit. Using the testing model, we could separate the superconductor from a circuit due to movement of vacuum interrupter within half-cycle current and transfer all current to bypass coil. Since operation of a commutation switch is included in current limiting operation of this testing model, it is one of helpful circuit of development of SFCL in the future. Moreover, since it can make the consumed energy of superconductor small during fault state due to realization of high-speed switch with simple composition, the burden of superconductor is reduced compared with conventional resistive type SFCL and it is considered that the flexibility of a SFCL design increases. Cooperation with a circuit breaker was also considered, the trial calculation of a parameter and energy of operation is conducted and discussion in the case of installing the SFCL to electric power system is made.

  2. Low power consumption current transducer

    NASA Technical Reports Server (NTRS)

    Mclyman, W. T. (Inventor)

    1989-01-01

    A low power consumption current transducer utilizes a saturable core reactor which includes a pair of opposed gate windings and a control winding. The control winding of the saturable reactor is arranged to receive the current to be measured. A square wave generator is connected to the gate winding of the transformer connected across the square wave generator and the secondary connected in series with the gate windings of the reactor. A full wave rectifier is connected to the gate windings and a resistor is connected across the rectifier to provide a DC voltage to cross it representative of the current flow through the control winding. A DC power supply is provided to supply power to the square wave voltage source. A diode is connected between each end of the primary winding of the transformer and one polarity of the DC power supply to commutate the reactive current resulting from the counter emf generated in the reactor back to the DC supply to eliminate potentially damaging reactive voltage spikes which would otherwise appear at the output of the square wave generator and conserve energy.

  3. Characterising food environment exposure at home, at work, and along commuting journeys using data on adults in the UK

    PubMed Central

    2013-01-01

    Background 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. Methods 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. Results 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. Conclusions Relying solely on residential neighbourhood characterisation greatly underestimated total

  4. A novel multi-commutated method for the determination of hydroxytyrosol in enriched foods using mercaptopropionic acid-capped CdTe quantum dots.

    PubMed

    Llorent-Martínez, E J; Molina-García, L; Fernández-de Córdova, M L; Santos, J L M; Rodrigues, S S M; Ruiz-Medina, A

    2013-01-01

    Hydroxytyrosol (HXT) has been reported to have beneficial effects for human health, such as antioxidant and antimicrobial properties and an important contribution to the prevention of cardiovascular disease. Hence, exhaustive research is currently being performed to prepare functional foods, such as tomato juice or milk, with HXT. This paper presents a multi-commutated flow method based on the quenching effect that HXT has on the fluorescence of water-soluble mercaptopropionic acid-capped CdTe quantum dots. Under optimal conditions a linear working range was obtained for concentrations between 10 and 250 ng µl⁻¹. In order to demonstrate the suitability of the proposed method for the determination of HXT, HXT-enriched samples were prepared. Using a QuEChERS (quick, easy, cheap, effective, rugged and safe) procedure for extraction, HXT was determined in the prepared functional foods (milk, infant formula, tomato juice and tomato soup). Recoveries of 100% ± 8%, relative standard deviations (RSDs) lower than 5% and high sample throughput of 70 samples per h show the potential of the system for the analysis of HXT in food samples.

  5. Research on a novel two-stage direct current hybrid circuit breaker.

    PubMed

    Wu, Yifei; Wu, Yi; Rong, Mingzhe; Yang, Fei; Niu, Chunping; Li, Mei; Hu, Yang

    2014-08-01

    The DC hybrid circuit breaker based on high-speed switch (HSS) and parallel connected capacitor has been widely applied in the fault current breaking of DC system. However, when the current is commutated from HSS to the capacitor according to single-stage operation, the capacitor has to absorb a large amount of energy stored in the system inductance within very short time. Meanwhile, a high over-voltage rate of rise is especially prone to be produced between the contacts of HSS, which will lead to a failed breaking. As a result, a novel DC hybrid circuit breaker based on the two-stage operation is proposed and analyzed in this paper. By controlling the thyristors in the commutation branches, the fault current is fast commutated into the capacitor, which can not only realize the arcless open of HSS, but also decrease the over-voltage rate of rise significantly in comparison to the traditional single-stage operation. The simulation model of fault current breaking under different conditions in 10 kV medium voltage DC system is constructed. The simulated over-voltages of single-stage and two-stage operations in the case of fault current breaking are compared and analyzed. Finally, the fault current breaking test in the two-stage operation is investigated experimentally, which validates the feasibility and effectiveness of the simulation model well.

  6. Research on a novel two-stage direct current hybrid circuit breaker

    NASA Astrophysics Data System (ADS)

    Wu, Yifei; Wu, Yi; Rong, Mingzhe; Yang, Fei; Niu, Chunping; Li, Mei; Hu, Yang

    2014-08-01

    The DC hybrid circuit breaker based on high-speed switch (HSS) and parallel connected capacitor has been widely applied in the fault current breaking of DC system. However, when the current is commutated from HSS to the capacitor according to single-stage operation, the capacitor has to absorb a large amount of energy stored in the system inductance within very short time. Meanwhile, a high over-voltage rate of rise is especially prone to be produced between the contacts of HSS, which will lead to a failed breaking. As a result, a novel DC hybrid circuit breaker based on the two-stage operation is proposed and analyzed in this paper. By controlling the thyristors in the commutation branches, the fault current is fast commutated into the capacitor, which can not only realize the arcless open of HSS, but also decrease the over-voltage rate of rise significantly in comparison to the traditional single-stage operation. The simulation model of fault current breaking under different conditions in 10 kV medium voltage DC system is constructed. The simulated over-voltages of single-stage and two-stage operations in the case of fault current breaking are compared and analyzed. Finally, the fault current breaking test in the two-stage operation is investigated experimentally, which validates the feasibility and effectiveness of the simulation model well.

  7. Dark matter with invisible light from heavy double charged leptons of almost-commutative geometry?

    NASA Astrophysics Data System (ADS)

    Khlopov, M. Yu; Stephan, C. A.; Fargion, D.

    2006-12-01

    A new candidate for cold dark matter arises from a novel elementary particle model: the almost-commutative AC-geometrical framework. Two heavy leptons are added to the standard model, each one sharing a double opposite electric charge and an own lepton flavour number. The novel mathematical theory of almost-commutative geometry (Connes 1994 Noncommutative Geometry (London: Academic)) wishes to unify gauge models with gravity. In this scenario two new heavy (mL >= 100 GeV), oppositely double charged leptons (A,C), (A with charge -2 and C with charge +2), are born with no twin quark companions. The model naturally involves a new U(1) gauge interaction, possessed only by the AC-leptons and providing a Coulomb-like attraction between them. AC-leptons posses electro-magnetic as well as Z-boson interaction and, according to the charge chosen for the new U(1) gauge interaction, a new 'invisible light' interaction. Their final cosmic relics are bounded into 'neutral' stable atoms (AC) forming the mysterious cold dark matter, in the spirit of the Glashow's Sinister model. An (AC) state is reached in the early Universe along a tail of a few secondary frozen exotic components. They should be here now somehow hidden in the surrounding matter. The two main secondary manifest relics are C2+ (mostly hidden in a neutral (C2+e-e-) 'anomalous helium' atom, at a 10-8 ratio) and a corresponding 'ion' A2- bounded with an ordinary helium ion (4He)2+; indeed the positive helium ions are able to attract and capture the free A2- fixing them into a neutral relic cage that has nuclear interaction (4He2+A2-). The cage preserves the leptons to later recombine with neutral (C2+e-e-) into (AC) evanescent states. In early and late cosmic stages (AC) gas is leading to cold dark matter gravity seeds. It can form dense cores inside dense matter bodies (stars and planets). Binding (C2+e-e-) + (4He2+A2-) into (AC) atoms results in a steady decrease of the anomalous isotopes and a growing concentration

  8. Road traffic injuries to children during the school commute in Hyderabad, India: cross-sectional survey

    PubMed Central

    Tetali, Shailaja; Murthy, G V S; Roberts, I

    2016-01-01

    Background 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. Methods 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. Results 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). Conclusions 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. PMID:26701985

  9. The impact of a Bus Rapid Transit system on commuters' exposure to Benzene, CO, PM 2.5 and PM 10 in Mexico City

    NASA Astrophysics Data System (ADS)

    Wöhrnschimmel, Henry; Zuk, Miriam; Martínez-Villa, Gerardo; Cerón, Julia; Cárdenas, Beatriz; Rojas-Bracho, Leonora; Fernández-Bremauntz, Adrián

    Carbon monoxide (CO), benzene and other volatile organic compounds (VOCs) and suspended particles PM 2.5 and PM 10 were measured inside public transportation vehicles, before and after a new Bus Rapid Transit (BRT) system was implemented in Mexico City in June 2005. The objective was to evaluate the BRT system's impact on commuters' exposure to these air pollutants. The BRT system replaced conventional transport modes along 20 km of Insurgentes Avenue, and features confined corridors and new articulated diesel buses. We assessed the impact of the transportation mode on commuters' exposure using least squares regression models. We also analyzed the chemical composition of VOCs to evaluate the possible origin of these species. The implementation of the BRT system resulted in reductions in commuters' exposure to CO, benzene and PM 2.5 ranging between 20% and 70%. No significant reductions in PM 10 exposure were observed. Lower commuting times further reduced total commuters' exposure. Major sources affecting VOCs inside all transport modes are likely to be related to traffic and to emissions from the use of Liquefied Petroleum Gas. The results suggest that BRT systems could in general be an effective means of reducing human exposure to traffic related air pollutants and associated health impacts.

  10. Healthy travel and the socio-economic structure of car commuting in Cambridge, UK: a mixed-methods analysis.

    PubMed

    Goodman, Anna; Guell, Cornelia; Panter, Jenna; Jones, Natalia R; Ogilvie, David

    2012-06-01

    Car use is associated with substantial health and environmental costs but research in deprived populations indicates that car access may also promote psychosocial well-being within car-oriented environments. This mixed-method (quantitative and qualitative) study examined this issue in a more affluent setting, investigating the socio-economic structure of car commuting in Cambridge, UK. Our analyses involved integrating self-reported questionnaire data from 1142 participants in the Commuting and Health in Cambridge study (collected in 2009) and in-depth interviews with 50 participants (collected 2009-2010). Even in Britain's leading 'cycling city', cars were a key resource in bridging the gap between individuals' desires and their circumstances. This applied both to long-term life goals such as home ownership and to shorter-term challenges such as illness. Yet car commuting was also subject to constraints, with rush hour traffic pushing drivers to start work earlier and with restrictions on, or charges for, workplace parking pushing drivers towards multimodal journeys (e.g. driving to a 'park-and-ride' site then walking). These patterns of car commuting were socio-economically structured in several ways. First, the gradient of housing costs made living near Cambridge more expensive, affecting who could 'afford' to cycle and perhaps making cycling the more salient local marker of Bourdieu's class distinction. Nevertheless, cars were generally affordable in this relatively affluent, highly-educated population, reducing the barrier which distance posed to labour-force participation. Finally, having the option of starting work early required flexible hours, a form of job control which in Britain is more common among higher occupational classes. Following a social model of disability, we conclude that socio-economic advantage can make car-oriented environments less disabling via both greater affluence and greater job control, and in ways manifested across the full socio

  11. Healthy travel and the socio-economic structure of car commuting in Cambridge, UK: A mixed-methods analysis

    PubMed Central

    Goodman, Anna; Guell, Cornelia; Panter, Jenna; Jones, Natalia R.; Ogilvie, David

    2012-01-01

    Car use is associated with substantial health and environmental costs but research in deprived populations indicates that car access may also promote psychosocial well-being within car-oriented environments. This mixed-method (quantitative and qualitative) study examined this issue in a more affluent setting, investigating the socio-economic structure of car commuting in Cambridge, UK. Our analyses involved integrating self-reported questionnaire data from 1142 participants in the Commuting and Health in Cambridge study (collected in 2009) and in-depth interviews with 50 participants (collected 2009–2010). Even in Britain's leading ‘cycling city’, cars were a key resource in bridging the gap between individuals' desires and their circumstances. This applied both to long-term life goals such as home ownership and to shorter-term challenges such as illness. Yet car commuting was also subject to constraints, with rush hour traffic pushing drivers to start work earlier and with restrictions on, or charges for, workplace parking pushing drivers towards multimodal journeys (e.g. driving to a ‘park-and-ride’ site then walking). These patterns of car commuting were socio-economically structured in several ways. First, the gradient of housing costs made living near Cambridge more expensive, affecting who could ‘afford’ to cycle and perhaps making cycling the more salient local marker of Bourdieu's class distinction. Nevertheless, cars were generally affordable in this relatively affluent, highly-educated population, reducing the barrier which distance posed to labour-force participation. Finally, having the option of starting work early required flexible hours, a form of job control which in Britain is more common among higher occupational classes. Following a social model of disability, we conclude that socio-economic advantage can make car-oriented environments less disabling via both greater affluence and greater job control, and in ways manifested across

  12. Current sensor

    DOEpatents

    Yakymyshyn, Christopher Paul; Brubaker, Michael Allen; Yakymyshyn, Pamela Jane

    2007-01-16

    A current sensor is described that uses a plurality of magnetic field sensors positioned around a current carrying conductor. The sensor can be hinged to allow clamping to a conductor. The current sensor provides high measurement accuracy for both DC and AC currents, and is substantially immune to the effects of temperature, conductor position, nearby current carrying conductors and aging.

  13. A systems approach to energy management and policy in commuter rail transportation

    NASA Astrophysics Data System (ADS)

    Owan, Ransome Egimine

    1998-12-01

    This research is motivated by a recognition of energy as a significant part of the transportation problem. Energy is a long-term variable cost that is controllable. The problem is comprised of: the limited supply of energy, chronic energy deficits and oil imports, energy cost, poor fuel substitution, and the undesirable environmental effects of transportation fuels (Green House Gases and global warming). Mass transit systems are energy intensive networks and energy is a direct constraint to the supply of affordable transportation. Commuter railroads are also relatively unresponsive to energy price changes due to travel demand patterns, firm power needs and slow adoption of efficient train technologies. However, the long term energy demand is lacking in existing transportation planning philosophy. In spite of the apparent oversight, energy is as important as urban land use, funding and congestion, all of which merit explicit treatment. This research was conducted in the form of a case study of New Jersey Transit in an attempt to broaden the understanding of the long-term effects of energy in a transportation environment. The systems approach method that is driven by heuristic models was utilized to investigate energy usage, transit peer group efficiency, energy management regimes, and the tradeoffs between energy and transportation, a seldom discussed topic in the field. Implicit in systems thinking is the methodological hunt for solutions. The energy problem was divided into thinking is the methodological hunt for solutions. The energy problem was divided into smaller parts that in turn were simpler to solve. The research presented five heuristic models: Transit Energy Aggregation Model, Structural Energy Consumption Model, Traction Power Consumption Model, Conjunctive Demand Model, and a Managerial Action Module. A putative relationship was established between traction energy, car-miles, seasonal and ambient factors, without inference of direct causality. The co

  14. EFFECTS OF LONG-TIME COMMUTING AND LONG-HOUR WORKING ON LIFESTYLE AND MENTAL HEALTH AMONG SCHOOL TEACHERS IN TOKYO, JAPAN.

    PubMed

    Nomoto, Marino; Hara, Akiko; Kikuchi, Kimiyo

    2015-06-01

    The objective of this study was to investigate the effects of long-time commuting and long-hour working on lifestyle including sleeping, physical exercise, breakfast, smoking, alcohol intake and mental health. In this cross-sectional study, data were collected from 146 school teachers in Tokyo. The binary associations of commuting time and working hours with lifestyle, mental stress measured by the General Health Questionnaire (GHQ) and stress coping measured by the Sense of Coherence (SOC) scores were examined. The Chi-square test was used for statistical analyses. Our results indicated that the mean commuting time and working hours per week of the respondents were 42.1 (SD 22.5) minutes and 50.4 (SD 8.6) hours, respectively. Longer commuting time was significantly associated with shorter working hours (p = 0.023), less physical exercise (p < 0.001) and shorter sleeping hours (p = 0.001). Longer working hours were significantly associated with more frequent working on holidays (p = 0.001), higher SOC scores (p = 0.001) and more smoking (p = 0.028). The negative association between GHQ and SOC scores was also significant (p < 0.001). Our findings revealed that long-time commuters were more likely to sleep less, exercise less and work less long. Long-hour workers were more likely to commute shorter, work on holidays more frequently, smoke more and their stress coping potentials were higher. Some kinds of strategies are required to improve the healthy lifestyle for long-time com- muters or long-hour workers. Key words: stress; stress coping; general health questionnaire; sense of coherence PMID:27281916

  15. EFFECTS OF LONG-TIME COMMUTING AND LONG-HOUR WORKING ON LIFESTYLE AND MENTAL HEALTH AMONG SCHOOL TEACHERS IN TOKYO, JAPAN.

    PubMed

    Nomoto, Marino; Hara, Akiko; Kikuchi, Kimiyo

    2015-06-01

    The objective of this study was to investigate the effects of long-time commuting and long-hour working on lifestyle including sleeping, physical exercise, breakfast, smoking, alcohol intake and mental health. In this cross-sectional study, data were collected from 146 school teachers in Tokyo. The binary associations of commuting time and working hours with lifestyle, mental stress measured by the General Health Questionnaire (GHQ) and stress coping measured by the Sense of Coherence (SOC) scores were examined. The Chi-square test was used for statistical analyses. Our results indicated that the mean commuting time and working hours per week of the respondents were 42.1 (SD 22.5) minutes and 50.4 (SD 8.6) hours, respectively. Longer commuting time was significantly associated with shorter working hours (p = 0.023), less physical exercise (p < 0.001) and shorter sleeping hours (p = 0.001). Longer working hours were significantly associated with more frequent working on holidays (p = 0.001), higher SOC scores (p = 0.001) and more smoking (p = 0.028). The negative association between GHQ and SOC scores was also significant (p < 0.001). Our findings revealed that long-time commuters were more likely to sleep less, exercise less and work less long. Long-hour workers were more likely to commute shorter, work on holidays more frequently, smoke more and their stress coping potentials were higher. Some kinds of strategies are required to improve the healthy lifestyle for long-time com- muters or long-hour workers. Key words: stress; stress coping; general health questionnaire; sense of coherence

  16. Commuter exposure to black carbon, carbon monoxide, and noise in the mass transport khlong boats of Bangkok, Thailand

    NASA Astrophysics Data System (ADS)

    Ziegler, A. D.; Velasco, E.; Ho, K. J.

    2013-12-01

    Khlong (canal) boats are a unique mass transport alternative in the congested city of Bangkok. Canals and rivers provide exclusive transit-ways for reducing the commuting time of thousands of city residents daily. However, as a consequence of the service characteristics and boats design and state of repair, they can represent a potential public health risk and an important source of black carbon and greenhouse gases. This work quantifies commuter exposure to black carbon, CO and noise when waiting for and travelling in these diesel fueled boats. Exposure to toxic pollutants and acute noise is similar or worse than for other transportation modes. Mean black carbon concentrations observed at one busy pier and along the main canal were much higher than ambient concentrations at sites impacted by vehicular traffic. Concentrations of CO were similar to those reported for roadside areas of Bangkok. The equivalent continuous sound levels registered at the landing pier were similar to those reported for roadsides, but values recorded inside the boats were significantly higher. We believe that the boat service is a viable alternative mode of mass transport, but public safety could be improved to provide a high quality service, comparable to modern rail systems or emerging bus rapid transit systems. These investments would also contribute to reduce the emission of black carbon and other greenhouse and toxic pollutants.

  17. The Societal Costs and Benefits of Commuter Bicycling: Simulating the Effects of Specific Policies Using System Dynamics Modeling

    PubMed Central

    Connor, Jennie; Witten, Karen; Kearns, Robin; Rees, David; Woodward, Alistair

    2014-01-01

    Background: Shifting to active modes of transport in the trip to work can achieve substantial co-benefits for health, social equity, and climate change mitigation. Previous integrated modeling of transport scenarios has assumed active transport mode share and has been unable to incorporate acknowledged system feedbacks. Objectives: We compared the effects of policies to increase bicycle commuting in a car-dominated city and explored the role of participatory modeling to support transport planning in the face of complexity. Methods: We used system dynamics modeling (SDM) to compare realistic policies, incorporating feedback effects, nonlinear relationships, and time delays between variables. We developed a system dynamics model of commuter bicycling through interviews and workshops with policy, community, and academic stakeholders. We incorporated best available evidence to simulate five policy scenarios over the next 40 years in Auckland, New Zealand. Injury, physical activity, fuel costs, air pollution, and carbon emissions outcomes were simulated. Results: Using the simulation model, we demonstrated the kinds of policies that would likely be needed to change a historical pattern of decline in cycling into a pattern of growth that would meet policy goals. Our model projections suggest that transforming urban roads over the next 40 years, using best practice physical separation on main roads and bicycle-friendly speed reduction on local streets, would yield benefits 10–25 times greater than costs. Conclusions: To our knowledge, this is the first integrated simulation model of future specific bicycling policies. Our projections provide practical evidence that may be used by health and transport policy makers to optimize the benefits of transport bicycling while minimizing negative consequences in a cost-effective manner. The modeling process enhanced understanding by a range of stakeholders of cycling as a complex system. Participatory SDM can be a helpful method

  18. 41 CFR 102-117.245 - What is my responsibility in providing guidance to an employee who wishes to use the commuted...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... responsibility in providing guidance to an employee who wishes to use the commuted rate system? 102-117.245... System (Continued) FEDERAL MANAGEMENT REGULATION TRANSPORTATION 117-TRANSPORTATION MANAGEMENT Shipping Household Goods § 102-117.245 What is my responsibility in providing guidance to an employee who wishes...

  19. 41 CFR 102-117.225 - What is the difference between a contract or a rate tender and a commuted rate system?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What is the difference between a contract or a rate tender and a commuted rate system? 102-117.225 Section 102-117.225 Public... MANAGEMENT REGULATION TRANSPORTATION 117-TRANSPORTATION MANAGEMENT Shipping Household Goods §...

  20. 41 CFR 302-7.101 - Where can the commuted rate schedules for the transportation of HHG, and temporary storage be found?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 4 2011-07-01 2011-07-01 false Where can the commuted....101 Public Contracts and Property Management Federal Travel Regulation System RELOCATION ALLOWANCES TRANSPORTATION AND STORAGE OF PROPERTY 7-TRANSPORTATION AND TEMPORARY STORAGE OF HOUSEHOLD GOODS AND...

  1. 41 CFR 102-117.225 - What is the difference between a contract or a rate tender and a commuted rate system?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false What is the difference between a contract or a rate tender and a commuted rate system? 102-117.225 Section 102-117.225 Public... MANAGEMENT REGULATION TRANSPORTATION 117-TRANSPORTATION MANAGEMENT Shipping Household Goods §...

  2. 41 CFR 302-7.101 - Where can the commuted rate schedules for the transportation of HHG, and temporary storage be found?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false Where can the commuted....101 Public Contracts and Property Management Federal Travel Regulation System RELOCATION ALLOWANCES TRANSPORTATION AND STORAGE OF PROPERTY 7-TRANSPORTATION AND TEMPORARY STORAGE OF HOUSEHOLD GOODS AND...

  3. 41 CFR 102-117.245 - What is my responsibility in providing guidance to an employee who wishes to use the commuted...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false What is my responsibility in providing guidance to an employee who wishes to use the commuted rate system? 102-117.245... Household Goods § 102-117.245 What is my responsibility in providing guidance to an employee who wishes...

  4. 41 CFR 102-117.245 - What is my responsibility in providing guidance to an employee who wishes to use the commuted...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false What is my responsibility in providing guidance to an employee who wishes to use the commuted rate system? 102-117.245... Household Goods § 102-117.245 What is my responsibility in providing guidance to an employee who wishes...

  5. 41 CFR 102-117.245 - What is my responsibility in providing guidance to an employee who wishes to use the commuted...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false What is my responsibility in providing guidance to an employee who wishes to use the commuted rate system? 102-117.245... Household Goods § 102-117.245 What is my responsibility in providing guidance to an employee who wishes...

  6. Library Service for Commuting Students: A Preliminary Study of Problems in Four Southeastern New York Counties. Studies in Interlibrary Relations, Number One.

    ERIC Educational Resources Information Center

    Gocek, Matilda A.

    This study of commuting student use of public libraries was confined to certain key public libraries in the New York counties of Orange, Rockland, Sullivan and a section of Ulster. The purpose of this preliminary enquiry was to determine: (1) what students use public library services, how often and what materials are sought, (2) the attitudes of…

  7. Personal exposure to particulate matter in commuters using different transport modes (bus, bicycle, car and subway) in an assigned route in downtown Santiago, Chile.

    PubMed

    Suárez, Liliana; Mesías, Stephanie; Iglesias, Verónica; Silva, Claudio; Cáceres, Dante D; Ruiz-Rudolph, Pablo

    2014-05-01

    The objective of this study was to compare personal exposure to particulate matter (fine and ultrafine particles) in commuters using different transport modes (bicycle, bus, car and subway) in a busy, assigned route in downtown Santiago, Chile. Volunteers carrying personal samplers completed scheduled commutes during the morning rush hours, while central site measurements were conducted in parallel. A total of 137 valid commutes were assessed. The impact of central site, traffic and other variables was explored with regression models. PM2.5 personal concentrations were equal to or slightly above central site measurements, while UFP personal concentrations were above them. Regression models showed impacts of both background levels and traffic emissions on personal PM2.5 and UFP exposure. Traffic impacts varied with transport modes. Estimates of traffic impacts on personal PM2.5 exposure were 2.0, 13.0, 16.9 and 17.5 μg m(-3), for car, bicycle, subway and bus, respectively; while for UFP exposure were 8400, 16 200, 25 600 and 30 100 counts per cm(3), for subway, car, bicycle and bus, respectively. After controlling the central site and transport mode, higher temperatures increased PM2.5 exposure and decreased UFP ones, while the wind direction affected UFP personal exposure. In conclusion, we found significant impacts of both central site background measurements and traffic emissions on personal exposure of volunteer commuters in an assigned route in Santiago, with impacts varying with transport modes.

  8. Using Crowdsourced Data (twitter & Facebook) to Delineate the Origin and Destination of Commuters of the Gautrain Public Transit System in South Africa

    NASA Astrophysics Data System (ADS)

    Moyo, T.; Musakwa, W.

    2016-06-01

    The study of commuters' origins and destinations (O_D) promises to assist transportation planners with prediction models to inform decision making. Conventionally OD surveys are undertaken through travel surveys and traffic counts, however data collection for these surveys has historically proven to be time consuming and having a strain on human resources, thus a need for an alternative data source arises. This study combines the use social media data and geographic information systems in the creation of a model for origin and destination surveys. The model tests the potential of using big data from Echo echo software which contains Twitter and Facebook data obtained from social media users in Gauteng. This data contains geo-location and it is used to determine origin and destination as well as concentration levels of Gautrain commuters. A kriging analysis was performed on the data to determine the O-D and concentration levels of Gautrain users. The results reveal the concentration of Gautrain commuters at various points of interest that is where they work, live or socialise. The results from the study highlight which nodes attract the most commuters and also possible locations for the expansion for Gautrain. Lastly, the study also highlights some weakness of crowdsourced data for informing transportation planning.

  9. The Impact of Additional Weekdays of Active Commuting to School on Children Achieving a Criterion of 300+ Minutes of Moderate-to-Vigorous Physical Activity

    ERIC Educational Resources Information Center

    Daly-Smith, Andy J. W.; McKenna, Jim; Radley, Duncan; Long, Jonathan

    2011-01-01

    Objective: To investigate the value of additional days of active commuting for meeting a criterion of 300+ minutes of moderate-to-vigorous physical activity (MVPA; 60+ mins/day x 5) during the school week. Methods: Based on seven-day diaries supported by teachers, binary logistic regression analyses were used to predict achievement of MVPA…

  10. 41 CFR 102-117.230 - Must I compare costs between a contract or a rate tender and the commuted rate system before...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false Must I compare costs... Shipping Household Goods § 102-117.230 Must I compare costs between a contract or a rate tender and the commuted rate system before choosing which method to use? Yes, you must compare the cost between a...

  11. 41 CFR 102-117.230 - Must I compare costs between a contract or a rate tender and the commuted rate system before...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Must I compare costs... Shipping Household Goods § 102-117.230 Must I compare costs between a contract or a rate tender and the commuted rate system before choosing which method to use? Yes, you must compare the cost between a...

  12. 41 CFR 102-117.230 - Must I compare costs between a contract or a rate tender and the commuted rate system before...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Must I compare costs... Shipping Household Goods § 102-117.230 Must I compare costs between a contract or a rate tender and the commuted rate system before choosing which method to use? Yes, you must compare the cost between a...

  13. 14 CFR Appendix F to Part 36 - Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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  14. 14 CFR Appendix F to Part 36 - Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests Prior to.... F Appendix F to Part 36—Flyover Noise Requirements for Propeller-Driven Small Airplane and...

  15. 14 CFR Appendix G to Part 36 - Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.); E. O. 11514, March 5, 1970 and 14 CFR... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests on or...

  16. 14 CFR Appendix F to Part 36 - Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests Prior to.... F Appendix F to Part 36—Flyover Noise Requirements for Propeller-Driven Small Airplane and...

  17. 14 CFR Appendix G to Part 36 - Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.); E. O. 11514, March 5, 1970 and 14 CFR... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests on or...

  18. 14 CFR Appendix F to Part 36 - Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests Prior to.... F Appendix F to Part 36—Flyover Noise Requirements for Propeller-Driven Small Airplane and...

  19. 14 CFR Appendix G to Part 36 - Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.); E. O. 11514, March 5, 1970 and 14 CFR... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests on or...

  20. 14 CFR Appendix G to Part 36 - Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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  1. 14 CFR Appendix F to Part 36 - Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Flyover Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests Prior to.... F Appendix F to Part 36—Flyover Noise Requirements for Propeller-Driven Small Airplane and...

  2. 14 CFR Appendix G to Part 36 - Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.); E. O. 11514, March 5, 1970 and 14 CFR... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter Category Airplane Certification Tests on or...

  3. Chow groups of intersections of quadrics via homological projective duality and (Jacobians of) non-commutative motives

    NASA Astrophysics Data System (ADS)

    Bernardara, M.; Tabuada, G.

    2016-06-01

    Conjectures of Beilinson-Bloch type predict that the low-degree rational Chow groups of intersections of quadrics are one-dimensional. This conjecture was proved by Otwinowska in [20]. By making use of homological projective duality and the recent theory of (Jacobians of) non-commutative motives, we give an alternative proof of this conjecture in the case of a complete intersection of either two quadrics or three odd-dimensional quadrics. Moreover, we prove that in these cases the unique non-trivial algebraic Jacobian is the middle one. As an application, we make use of Vial's work [26], [27] to describe the rational Chow motives of these complete intersections and show that smooth fibrations into such complete intersections over bases S of small dimension satisfy Murre's conjecture (when \\dim (S)≤ 1), Grothendieck's standard conjecture of Lefschetz type (when \\dim (S)≤ 2), and Hodge's conjecture (when \\dim(S)≤ 3).

  4. G/G gauged WZW-matter model, Bethe Ansatz for q-boson model and Commutative Frobenius algebra

    NASA Astrophysics Data System (ADS)

    Okuda, Satoshi; Yoshida, Yutaka

    2014-03-01

    We investigate the correspondence between two dimensional topological gauge theories and quantum integrable systems discovered by Moore, Nekrasov, Shatashvili. This correspondence means that the hidden quantum integrable structure exists in the topological gauge theories. We showed the correspondence between the G/G gauged WZW model and the phase model in JHEP 11 (2012) 146 (arXiv:1209.3800). In this paper, we study a one-parameter deformation for this correspondence and show that the G/G gauged WZW model coupled to additional matters corresponds to the q-boson model. Furthermore, we investigate this correspondence from the viewpoint of the commutative Frobenius algebra, the axiom of the two dimensional topological quantum field theory.

  5. Commute alternatives educational outreach. Transportation demand management resource program for the transportation professional. Report for July 1993-December 1994

    SciTech Connect

    Winters, P.L.; Rudge, D.E.

    1995-01-01

    This project is designed to aid in the planning, implementation, evaluation, and improvements of a (TDM) agency of program. Through the use of examples, the TDM professional can review innovative programs and initiatives throughout the United States, and model activities after these exhibits. The equations and benchmarks cited by this publication are other effective tools which offer insights into the relative success of TDM plan components in various environments. This report also introduces many of the traditional and innovative commute alternatives and discusses the benefits, obstacles, and goals of these initiatives. Strategies including carpooling, vanpooling, telecommuting, tax incentives, guaranteed ride home programs, bicycle and pedestrian facilities, transit, telecommuting, alternative work hour programs, and intermodalism are discussed and evaluated in real-world scenarios.

  6. Piloted simulation study of an ILS approach of a twin-pusher business/commuter turboprop aircraft configuration

    NASA Technical Reports Server (NTRS)

    Riley, Donald R.; Brandon, Jay M.; Glaab, Louis J.

    1994-01-01

    A six-degree-of-freedom nonlinear simulation of a twin-pusher, turboprop business/commuter aircraft configuration representative of the Cessna ATPTB (Advanced turboprop test bed) was developed for use in piloted studies with the Langley General Aviation Simulator. The math models developed are provided, simulation predictions are compared with with Cessna flight-test data for validation purposes, and results of a handling quality study during simulated ILS (instrument landing system) approaches and missed approaches are presented. Simulated flight trajectories, task performance measures, and pilot evaluations are presented for the ILS approach and missed-approach tasks conducted with the vehicle in the presence of moderate turbulence, varying horizontal winds and engine-out conditions. Six test subjects consisting of two research pilots, a Cessna test pilot, and three general aviation pilots participated in the study. This effort was undertaken in cooperation with the Cessna Aircraft Company.

  7. Direct current ballast circuit for metal halide lamp

    NASA Technical Reports Server (NTRS)

    Lutus, P. (Inventor)

    1981-01-01

    A direct current ballast circuit for a two electrode metal halide lamp is described. Said direct current ballast circuit includes a low voltage DC input and a high frequency power amplifier and power transformer for developing a high voltage output. The output voltage is rectified by diodes and filtered by inductor and capacitor to provide a regulated DC output through commutating diodes to one terminal of the lamp at the output terminal. A feedback path from the output of the filter capacitor through the bias resistor to power the high frequency circuit which includes the power amplifier and the power transformer for sustaining circuit operations during low voltage transients on the input DC supply is described. A current sensor connected to the output of the lamp through terminal for stabilizing lamp current following breakdown of the lamp is described.

  8. Quantifying the physical activity energy expenditure of commuters using a combination of global positioning system and combined heart rate and movement sensors

    PubMed Central

    Costa, Silvia; Ogilvie, David; Dalton, Alice; Westgate, Kate; Brage, Søren; Panter, Jenna

    2015-01-01

    Background Active commuting may help to increase adults' physical activity levels. However, estimates of its energy cost are derived from a small number of studies which are laboratory-based or use self-reported measures. Methods Adults working in Cambridge (UK) recruited through a predominantly workplace-based strategy wore combined heart rate and movement sensors and global positioning system (GPS) devices for one week, and completed synchronous day-by-day travel diaries in 2010 and 2011. Commuting journeys were delineated using GPS data, and metabolic intensity (standard metabolic equivalents; MET) was derived and compared between journey types using mixed-effects linear regression. Results 182 commuting journeys were included in the analysis. Median intensity was 1.28 MET for car journeys; 1.67 MET for bus journeys; 4.61 MET for walking journeys; 6.44 MET for cycling journeys; 1.78 MET for journeys made by car in combination with walking; and 2.21 MET for journeys made by car in combination with cycling. The value for journeys made solely by car was significantly lower than those for all other journey types (p < 0.04). On average, 20% of the duration of journeys incorporating any active travel (equating to 8 min) was spent in moderate-to-vigorous physical activity (MVPA). Conclusions We have demonstrated how GPS and activity data from a free-living sample can be used simultaneously to provide objective estimates of commuting energy expenditure. On average, incorporating walking or cycling into longer journeys provided over half the weekly recommended activity levels from the commute alone. This may be an efficient way of achieving physical activity guidelines and improving population health. PMID:26441297

  9. Carbon monoxide levels measured in major commuting corridors covering different landuse and roadway microenvironments in Hong Kong

    NASA Astrophysics Data System (ADS)

    Chan, L. Y.; Liu, Y. M.; Lee, S. C.; Chan, C. Y.

    Vehicle exhaust is the major source of pollutant in modern cities. About half of Hong Kong residents are living in suburban or rural areas. They need to traverse through tunnels, highways, urban street canyons and other road conditions in different landuse areas when they traverse to work in urban centres or new towns. Also, there is increasing traffic, especially trucks across the border between Hong Kong and mainland China via several border highways. This study helps us in assessing the exposure level of suburban and cross border commuters. Carbon monoxide (CO) is used as a tracer for traffic emission. An experimental vehicle traversing major commuting corridors were used to measure CO levels in different landuse and roadway microenvironments including tunnels and highways. The air samples were taken simultaneously at the outside and inside of a travelling vehicle. Result indicates that the pattern of fluctuation of the out-vehicle and in-vehicle CO level vary with different landuse areas. The variation pattern of in-vehicle CO level is closely related to that of out-vehicle level. The effects of the out-vehicle CO concentration on the in-vehicle CO concentration under different roadway conditions in various landuse categories are examined. There is an indication that external air pollutants penetrated into the in-vehicle compartment through car body cracks, ventilation system. From our observation, the exhaust of a nearby petrol vehicle contributed significantly to the in-vehicle CO level. The use of low standard of diesel fuel from Shenzhen in mainland China leads to higher CO level near border area.

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

    PubMed Central

    Martin, Adam; Goryakin, Yevgeniy; Suhrcke, Marc

    2014-01-01

    Objective The aim of this study is to explore the relationship between active travel and psychological wellbeing. Method 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. Results 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 10 minute 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. Conclusion The positive psychological wellbeing effects identified in this study should be considered in cost–benefit assessments of interventions seeking to promote active travel. PMID:25152507

  11. Associations of Physical Activity, Sports Participation and Active Commuting on Mathematic Performance and Inhibitory Control in Adolescents

    PubMed Central

    Huang, Tao; Gejl, Anne Kær; Froberg, Karsten

    2016-01-01

    Objectives To examine objectively measured physical activity level, organized sports participation and active commuting to school in relation to mathematic performance and inhibitory control in adolescents. Methods The design was cross-sectional. A convenient sample of 869 sixth and seventh grade students (12–14 years) was invited to participate in the study. A total of 568 students fulfilled the inclusion criteria and comprised the final sample for this study. Mathematic performance was assessed by a customized test and inhibitory control was assessed by a modified Eriksen flanker task. Physical activity was assessed with GT3X and GT3X+ accelerometers presented in sex-specific quartiles of mean counts per minute and mean minutes per day in moderate-to-vigorous physical activity. Active commuting and sports participation was self-reported. Mixed model regression was applied. Total physical activity level was stratified by bicycling status in order to bypass measurement error subject to the accelerometer. Results Non-cyclists in the 2nd quartile of counts per minute displayed a higher mathematic score, so did cyclists in the 2nd and 3rd quartile of moderate-to-vigorous physical activity relative to the least active quartile. Non-cyclists in the 3rd quartile of counts per minute had an improved reaction time and cyclists in the 2nd quartile of counts per minute and moderate-to-vigorous physical activity displayed an improved accuracy, whereas non-cyclists in the 2nd quartile of counts per minute showed an inferior accuracy relative to the least active quartile. Bicycling to school and organized sports participation were positively associated with mathematic performance. Conclusions Sports participation and bicycling were positively associated with mathematic performance. Results regarding objectively measured physical activity were mixed. Although, no linear nor dose-response relationship was observed there was no indication of a higher activity level impairing the

  12. Reducing travel by design: a micro analysis of new household location and the commute to work in Surrey

    NASA Astrophysics Data System (ADS)

    Hickman, Robin

    Traffic volumes (and hence energy consumption) from the transport sector continue to rise, yet the potential fundamental role of urban planning in helping to reduce transport energy consumption remains to be poorly understood and hugely underplayed. Current urban planning practice, particularly in suburban areas, tends to increase traffic volumes by dispersing activities and hence facilitates private car travel rather than travel by public transport, walking or cycling. Public transport orientated development as an evolving practice tends to be focused very much on urban areas. This thesis seeks to understand the logic behind travel and suggests that urban planning can be applied more fully, at the strategic and local levels, to reduce energy consumption in car use (at least in the journey to work). The detailed analysis assesses the extent to which the design of the urban environment affects travel behaviour. The research hypothesis is that: "Journey to work travel behaviour generated by new residential development is dependent on a number of land use and socio-economic variables. The strength, significance and range of interaction vary spatially and over time." Within the analysis, the journey to work is used as the dependent variable, and is measured in terms of journey length and time, mode share and composite energy consumption. The independent variables considered include: Land use: resident population density, resident employment density, workplace population density, workplace employment density, resident population size, workplace population size, distance from urban centres and strategic transport networks, jobs-housing balance, resident classification (relative to the urban area), type of journey to work, neighbourhood streetscape design, public transport accessibility, and resident location (relative to the green belt). Socio-economic: household tenure, house type, house size, number of children, car availability, company car ownership, household income

  13. Current limiters

    SciTech Connect

    Loescher, D.H.; Noren, K.

    1996-09-01

    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  14. Stray current control in rehabilitating rail transit facilities

    SciTech Connect

    Fitzgerald, J.H. III; Bosma, R.; Paladines, F.

    1999-05-01

    An old Chicago direct current electrified railway yard and shop are being rehabilitated. Modern stray current control techniques are being introduced. Efficient rail operation and safety for the public and operating personnel are paramount. Metra is Chicago's commuter railroad, serving six counties in the metropolitan area. The Electric District, which was electrified in 1926, is a heavy rail system from downtown, serving the south side and suburbs. Operating on the same tracks from Randolph St., to Kensington is America's last electric interurban line, the Chicago South Shore and South Bend Railroad. All trains operate on 1,500-V direct current (DC) propulsion from an overhead catenary system, with the running rails as the negative return.

  15. Women's Perspectives on Retention in Higher Education in Jordan: Commute and Choice

    ERIC Educational Resources Information Center

    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…

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

    PubMed Central

    Heinen, Eva; 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. 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. Results 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). Conclusions 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. PMID

  17. Low-speed wind-tunnel investigation of the flight dynamic characteristics of an advanced turboprop business/commuter aircraft configuration

    NASA Technical Reports Server (NTRS)

    Coe, Paul L., Jr.; Turner, Steven G.; Owens, D. Bruce

    1990-01-01

    An investigation was conducted to determine the low-speed flight dynamic behavior of a representative advanced turboprop business/commuter aircraft concept. Free-flight tests were conducted in the NASA Langley Research Center's 30- by 60-Foot Tunnel. In support of the free-flight tests, conventional static, dynamic, and free-to-roll oscillation tests were performed. Tests were intended to explore normal operating and post stall flight conditions, and conditions simulating the loss of power in one engine.

  18. An overview of the small engine component technology (SECT) studies. [commuter, rotorcraft, cruise missile and auxiliary power applications in year 2000

    NASA Technical Reports Server (NTRS)

    Vanco, M. R.; Wintucky, W. T.; Niedwiecki, R. W.

    1986-01-01

    The objectives of the joint NASA/Army SECT studies were to identify high payoff technologies for year 2000 small gas turbine engine applications and to provide a technology plan for guiding future research and technology efforts applicable to rotorcraft, commuter and general aviation aircraft and cruise missiles. Competitive contracts were awarded to Allison, AVCO Lycoming, Garrett, Teledyne CAE and Williams International. This paper presents an overview of the contractors' study efforts for the commuter, rotorcraft, cruise missile, and auxiliary power (APU) applications with engines in the 250 to 1,000 horsepower size range. Reference aircraft, missions and engines were selected. Advanced engine configurations and cycles with projected year 2000 component technologies were evaluated and compared with a reference engine selected by the contractor. For typical commuter and rotorcraft applications, fuel savings of 22 percent to 42 percent can be attained. For $1/gallon and $2/gallon fuel, reductions in direct operating cost range from 6 percent to 16 percent and from 11 percent to 17 percent respectively. For subsonic strategic cruise missile applications, fuel savings of 38 percent to 54 percent can be achieved which allows 35 percent to 60 percent increase in mission range and life cycle cost reductions of 40 percent to 56 percent. High payoff technologies have been identified for all applications.

  19. Current Titles

    SciTech Connect

    Various

    2006-06-01

    This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Jane Cavlina, Administrator, at 510/486-6036.

  20. Estimation of the carbon monoxide emissions due to Sandia National Laboratories commuter and on-base traffic for conformity determination

    SciTech Connect

    McClellan, Y.; Royer, R.

    1996-09-01

    This report describes the analysis and conclusion of an investigation of the carbon monoxide emissions resulting from Sandia National Laboratories and Department of Energy (DOE) commuter and on-base traffic for the Clean Air Act (CAA) Conformity Determination. Albuquerque/Bernalillo County was classified as a nonattainment area by the Environmental Protection Agency. Nonattainment area is an area which is shown by monitored data or which is calculated by air quality modeling to exceed any National Ambient Air Quality Standard (NAAQS) for the pollutant. Albuquerque/Bernalillo County exceeds the NAAQS for carbon monoxide and ozone. The Conformity Determination was needed to complete the CAA Title V Permitting process for SNL and the DOE. The analysis used the EPA approved MOBILE5a Carbon Monoxide (CO) emissions modeling program. This analysis will provide a baseline for mobile sources to allow Sandia to estimate any future activity and how that activity will impact CO emissions. The General Conformity Rule (AQCR 43) requires that operations which will increase CO emissions in nonattaimnent or maintenance areas such as Bernalillo County undergo conformity analyses to determine whether or not they will impact ambient air quality in the area.