Soft-commutated direct current motor
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.
Soft-commutated direct current motor
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.
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.
Soft commutated direct current motor [summary of proposed paper
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.
Study of high current commutation by explosive switch
NASA Astrophysics Data System (ADS)
Usuba, S.; Kakudate, Y.; Yoshida, M.; Fujiwara, S.; Miyamoto, M.; Morita, T.; Kubota, A.; den, M.
1993-01-01
The study presents the basic experimental data obtained with a large current opening switch for current commutation using explosives. It is shown that currents up to a maximum of 40 kA can be completely interrupted within 30 microsec. The mechanism of current interruption using a thin conductor plate and methods of measuring interrupting current with a pickup coil and taking photographs with a high-speed camera (one frame per microsec) are discussed.
Commuter rail state-of-the-art: A study of current systems. Final report
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.
NASA Astrophysics Data System (ADS)
Lee, Jong-Geon; Khan, Umer Amir; Lee, Ho-Yun; Lim, Sung-Woo; Lee, Bang-Wook
2016-11-01
Commutation failure in line commutated converter based HVDC systems cause severe damages on the entire power grid system. For LCC-HVDC, thyristor valves are turned on by a firing signal but turn off control is governed by the external applied AC voltage from surrounding network. When the fault occurs in AC system, turn-off control of thyristor valves is unavailable due to the voltage collapse of point of common coupling (PCC), which causes the commutation failure in LCC-HVDC link. Due to the commutation failure, the power transfer interruption, dc voltage drop and severe voltage fluctuation in the AC system could be occurred. In a severe situation, it might cause the protection system to block the valves. In this paper, as a solution to prevent the voltage collapse on PCC and to limit the fault current, the application study of resistive superconducting fault current limiter (SFCL) on LCC-HVDC grid system was performed with mathematical and simulation analyses. The simulation model was designed by Matlab/Simulink considering Haenam-Jeju HVDC power grid in Korea which includes conventional AC system and onshore wind farm and resistive SFCL model. From the result, it was observed that the application of SFCL on LCC-HVDC system is an effective solution to mitigate the commutation failure. And then the process to determine optimum quench resistance of SFCL which enables the recovery of commutation failure was deeply investigated.
Systems and methods for commutating inductor current using a matrix converter
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.
A novel post-arc current measuring equipment based on vacuum arc commutation and arc blow
NASA Astrophysics Data System (ADS)
Liao, Minfu; Ge, Guowei; Duan, Xiongying; Huang, Zhihui
2017-07-01
The paper proposes a novel post-arc current measuring equipment (NPACME), which is based on the vacuum arc commutation and magnetic arc blow. The NPACME is composed of the vacuum circuit breaker (VCB), shunt resistor, protective gap, high-precision current sensor and externally applied transverse magnetic field (ETMF). The prototype of the NPACME is designed and controlled by optical fiber communications. The vacuum arc commutation between the vacuum arc and the shunt resistor with ETMF is investigated. The test platform is established in the synthetic short-circuit test and the vacuum arc is observed by the high speed CMOS camera. The mathematic description of the vacuum arc commutation is obtained. Based on the current commutation characteristic, the parameters of the NPACME are optimized and the post-arc current is measured. The measuring result of the post-arc current is accurate with small interference and the post-arc charge is obtained. The experimental results verify that the NPACME is correct and accurate, which can be used to measure the post-arc characteristic in breaking test.
A DIRECT CURRENT MOTOR WITH NO CONTACTS AND A TRANSISTOR COMMUTATOR.
dc motor of low power in which the collector is replaced by a transistor commutator controlled by a transformer sensor of the position of the rotor with respect to the stator. The rotor of the motor consists of a 2-pole permanent magnet. The transistor commutator of the motor may be used as a power amplifier. Control of motor speed is easily accomplished by means of modulating the input signals to the commutator. The motor is controlled by signals of low power which makes it possible to use it in automatic control systems without the use of very powerful additional
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.
Making almost commuting matrices commute
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.
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.
Commutation circuit for an HVDC circuit breaker
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.
Commutation circuit for an HVDC circuit breaker
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.
Commutation circuit for an HVDC circuit breaker
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.
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.
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.
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.
A wideband current-commutating passive mixer for multi-standard receivers in a 0.18 μm CMOS
NASA Astrophysics Data System (ADS)
Kuan, Bao; Xiangning, Fan; Wei, Li; Zhigong, Wang
2013-01-01
This paper reports a wideband passive mixer for direct conversion multi-standard receivers. A brief comparison between current-commutating passive mixers and active mixers is presented. The effect of source and load impedance on the linearity of a mixer is analyzed. Specially, the impact of the input impedance of the transimpedance amplifier (TIA), which acts as the load impedance of a mixer, is investigated in detail. The analysis is verified by a passive mixer implemented with 0.18 μm CMOS technology. The circuit is inductorless and can operate over a broad frequency range. On wafer measurements show that, with radio frequency (RF) ranges from 700 MHz to 2.3 GHz, the mixer achieves 21 dB of conversion voltage gain with a -1 dB intermediate frequency (IF) bandwidth of 10 MHz. The measured IIP3 is 9 dBm and the measured double-sideband noise figure (NF) is 10.6 dB at 10 MHz output. The chip occupies an area of 0.19 mm2 and drains a current of 5.5 mA from a 1.8 V supply.
Inductively commutated coilguns
Mongeau, P.P. )
1991-01-01
In this paper the concept and relevance of power factor is presented in regards to high performance launchers. As the scale of launchers grows and as efforts to improve efficiency continue power factor considerations will become crucial in engineering design and ultimate launcher performance limits. The use of motion induced commutation to improve the power factor are discussed. Various approaches to inductive commutation are presented, including: the brush-commutated 9 MJ Coilgun, the solid state-switched coilgun and the quenchgun.
Can advanced technology improve future commuter aircraft
NASA Technical Reports Server (NTRS)
Williams, L. J.; Snow, D. B.
1981-01-01
The short-haul service abandoned by the trunk and local airlines is being picked up by the commuter airlines using small turboprop-powered aircraft. Most of the existing small transport aircraft currently available represent a relatively old technology level. However, several manufacturers have initiated the development of new or improved commuter transport aircraft. These aircraft are relatively conservative in terms of technology. An examination is conducted of advanced technology to identify those technologies that, if developed, would provide the largest improvements for future generations of these aircraft. Attention is given to commuter aircraft operating cost, aerodynamics, structures and materials, propulsion, aircraft systems, and technology integration. It is found that advanced technology can improve future commuter aircraft and that the largest of these improvements will come from the synergistic combination of technological advances in all of the aircraft disciplines. The most important goals are related to improved fuel efficiency and increased aircraft productivity.
Impulse commutating circuit with transformer to limit reapplied voltage
NASA Technical Reports Server (NTRS)
Mcconville, J. H.
1973-01-01
Silicon controlled rectifier opens circuit with currents flowing up to values of 30 amperes. Switching concept halves both current and voltage in middle of commutating cycle thereby lowering size and weight requirements. Commutating circuit can be turned on or off by command and will remain on in absence of load due to continuous gate.
Commutated automatic gain control system
NASA Technical Reports Server (NTRS)
Yost, S. R.
1982-01-01
The commutated automatic gain control (AGC) system was designed and built for the prototype Loran-C receiver is discussed. The current version of the prototype receiver, the Mini L-80, was tested initially in 1980. The receiver uses a super jolt microcomputer to control a memory aided phase loop (MAPLL). The microcomputer also controls the input/output, latitude/longitude conversion, and the recently added AGC system. The AGC control adjusts the level of each station signal, such that the early portion of each envelope rise is about at the same amplitude in the receiver envelope detector.
Center Gets Commuters, Residents Together.
ERIC Educational Resources Information Center
American School and University, 1979
1979-01-01
The new student center at Trenton State College is situated on the walkway between the central campus and the commuter parking areas. The location brings resident and commuter students together. (Author/MLF)
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…
USDA-ARS?s Scientific Manuscript database
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...
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…
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.
Employee commute options guidance
Not Available
1992-12-01
The Clean Air Act Amendments of 1990 (CAAA) require severe and extreme ozone nonattainment areas and serious carbon monoxide nonattainment areas to establish programs aimed at reducing commute trips to the worksites of large employers. The concerns that lead to the inclusion of the Employee Commute Options (ECO) provision in the Act are that more people are driving than ever before and they are driving longer distances. The purpose of the guidance is to inform the affected State and local jurisdictions of the Clean Air Act requirement, to provide guidance on preparing an approvable State Implementation Plan (SIP) revision, and to discuss various approaches which may help areas achieve Clean Air Act targets through implementation strategies that are the least burdensome and costly to both affected employers and employees.
Radar channel balancing with commutation
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.
Commutator of gauge generators in non-abelian chiral theory
NASA Astrophysics Data System (ADS)
Jo, S.
1985-09-01
Commutators among non-abelian fermion currents are calculated using the BJL limit. The relation between the covariant seagull and the gauge dependence of the fermion current is derived for a canonical non-abelian theory using the path integral formulation. We observe that in a non-abelian theory with coupling to chiral fermions this relation is violated and this produces a non-trivial commutator of gauge group generators.
Electronically commutated serial-parallel switching for motor windings
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.
Mechanism For Adjustment Of Commutation Of Brushless Motor
NASA Technical Reports Server (NTRS)
Schaefer, Richard E.
1995-01-01
Mechanism enables adjustment of angular position of set of Hall-effect devices that sense instantaneous shaft angle of brushless dc motor. Outputs of sensors fed to commutation circuitry. Measurement of shaft angle essential for commutation; that is, application of voltage to stator windings must be synchronized with shaft angle. To obtain correct angle measurement for commutation, Hall-effect angle sensors positioned at proper reference angle. The present mechanism accelerates adjustment procedure and makes it possible to obtain more accurate indication of minimum-current position because it provides for adjustment while motor running.
Commutative POVMs and Fuzzy Observables
NASA Astrophysics Data System (ADS)
Ali, S. Twareque; Carmeli, Claudio; Heinosaari, Teiko; Toigo, Alessandro
2009-06-01
In this paper we review some properties of fuzzy observables, mainly as realized by commutative positive operator valued measures. In this context we discuss two representation theorems for commutative positive operator valued measures in terms of projection valued measures and describe, in some detail, the general notion of fuzzification. We also make some related observations on joint measurements.
Commuter Mobility and the Spread of Infectious Diseases: Application to Influenza in France
Charaudeau, Segolene; Pakdaman, Khashayar; Boëlle, Pierre-Yves
2014-01-01
Commuting data is increasingly used to describe population mobility in epidemic models. However, there is little evidence that the spatial spread of observed epidemics agrees with commuting. Here, using data from 25 epidemics for influenza-like illness in France (ILI) as seen by the Sentinelles network, we show that commuting volume is highly correlated with the spread of ILI. Next, we provide a systematic analysis of the spread of epidemics using commuting data in a mathematical model. We extract typical paths in the initial spread, related to the organization of the commuting network. These findings suggest that an alternative geographic distribution of GP accross France to the current one could be proposed. Finally, we show that change in commuting according to age (school or work commuting) impacts epidemic spread, and should be taken into account in realistic models. PMID:24416152
Commuter mobility and the spread of infectious diseases: application to influenza in France.
Charaudeau, Segolene; Pakdaman, Khashayar; Boëlle, Pierre-Yves
2014-01-01
Commuting data is increasingly used to describe population mobility in epidemic models. However, there is little evidence that the spatial spread of observed epidemics agrees with commuting. Here, using data from 25 epidemics for influenza-like illness in France (ILI) as seen by the Sentinelles network, we show that commuting volume is highly correlated with the spread of ILI. Next, we provide a systematic analysis of the spread of epidemics using commuting data in a mathematical model. We extract typical paths in the initial spread, related to the organization of the commuting network. These findings suggest that an alternative geographic distribution of GP accross France to the current one could be proposed. Finally, we show that change in commuting according to age (school or work commuting) impacts epidemic spread, and should be taken into account in realistic models.
1979-12-01
AD-AOBS 567 ITT GILFILLAN VAN NUYS CA F/6 17/9 CONF4UTATING FEED ASSEMBLY. 1W DEC 79 R WOL.FSON F19628-79-C-OOSS UNCLASSIFIED RADC -TR79303 NI. 1i.ll...INTRODUCTION 9 2 COMMUTATING FEED ASSEMBLY REQUIREMENTS 10 . 3 TECHNICAL PROBLEMS 11 1: 3.1 System Design 12 3.1.1 Radius of Circular Array 12 3.1.2 Design...Support Structure 16 3.3 Annular Rotary Coupler 16 3.4 Stripline Feed Network 17 w V.3.4.1 Range of Coupling Values vs. Percent Power into Load 17 3.4.2
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.
Gravity from a modified commutator
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.
Non-Commutative Martingale Inequalities
NASA Astrophysics Data System (ADS)
Pisier, Gilles; Xu, Quanhua
We prove the analogue of the classical Burkholder-Gundy inequalites for non-commutative martingales. As applications we give a characterization for an Ito-Clifford integral to be an Lp-martingale via its integrand, and then extend the Ito-Clifford integral theory in L2, developed by Barnett, Streater and Wilde, to Lp for all 1
commutative analogue of the classical Fefferman duality between $H1 and BMO.
Commuting projections on graphs
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 ℓ_{2}-projection Q_{H} 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 Q_{H} commute with the discrete divergence operator, i.e., we have div π _{H} = Q_{H} 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.
Herrador-Colmenero, Manuel; Álvarez-Gallardo, Inmaculada C; Segura-Jiménez, Víctor; Estévez-López, Fernando; Soriano-Maldonado, Alberto; Ruiz-Montero, Pedro J; Tercedor, Pablo; Girela-Rejón, María José; Delgado-Fernández, Manuel; Chillón, Palma
2016-01-01
The aims of this study were to know whether active commuting behaviour differs between fibromyalgia patients and controls, and to test whether active commuting is associated with socioeconomic factors in this population. This cross-sectional study included 459 women with fibromyalgia (52.2 years) and 214 female control participants (51.3 years) from Andalusia (southern Spain). Participants reported patterns of active commuting and socioeconomic factors (civil status, accompaniment at home, living with, educational level, and current occupational and professional status). On the age group <51 years, women with fibromyalgia revealed a significant higher percentage of active commuting for the variable active worker commuters than control group (p<0.05). On the age group ≥51 years, control group displayed a significant higher percentage of active commuting for commuting to local shops, super-market and active commuters variables (all, p<0.05). Women with fibromyalgia who lived alone were more active commuters in comparison to either those living accompanied, or living with both partner and children, only partner and only children (all, p<0.05). The prevalence of active commuting was similar in women with fibromyalgia and controls aged <51 years. However, fibromyalgia participants aged ≥51 years displayed differences: fibromyalgia women who lived alone were more active commuters than those living accompanied; family demands were inversely associated with commuting patterns. Policies focused on reducing family demands for fibromyalgia patients (i.e. social help on housework, childcare or overprotection) might facilitate the inclusion of daily active behaviours.
Future Propulsion Opportunities for Commuter Airplanes
NASA Technical Reports Server (NTRS)
Strack, W. C.
1982-01-01
Commuter airplane propulsion opportunities are summarized. Consideration is given to advanced technology conventional turboprop engines, advanced propellers, and several unconventional alternatives: regenerative turboprops, rotaries, and diesels. Advanced versions of conventional turboprops (including propellers) offer 15-20 percent savings in fuel and 10-15 percent in DOC compared to the new crop of 1500-2000 SHP engines currently in development. Unconventional engines could boost the fuel savings to 30-40 percent. The conclusion is that several important opportunities exist and, therefore, powerplant technology need not plateau.
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…
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…
The Added Benefit of Bicycle Commuting on the Regular Amount of Physical Activity Performed.
Donaire-Gonzalez, David; de Nazelle, Audrey; Cole-Hunter, Tom; Curto, Ariadna; Rodriguez, Daniel A; Mendez, Michelle A; Garcia-Aymerich, Judith; Basagaña, Xavier; Ambros, Albert; Jerrett, Michael; Nieuwenhuijsen, Mark J
2015-12-01
Physical inactivity is a leading cause of death and disability globally. Active transportation such as bicycling may increase physical activity levels. It is currently uncertain whether a shift from motorized transport modes to bicycle commuting leads to increased physical activity overall or substitutes other forms of physical activity. The study aims to disentangle whether bicycle commuting adds to or replaces other physical activities by comparing the physical activity performed by bicycle and motorized commuters. Physical activity, travel behavior, health status, sociodemographic, and built environment characteristics were assessed for 752 adults, between June 2011 and May 2012, in Barcelona, Spain. Statistical analyses, performed in 2013-2014, included linear, non-linear, and mixture models to estimate disparities and the dose-response relationship between physical activity duration and commute mode. Regular bicycle commuters traveled by bicycle an average of 3.1 (SD=2.5) hours in the previous week. Bicycle commuting contributed positively to physical activity duration across participants (p<0.05). It amounted to 2.1 (95% CI=0.84, 3.55) hours/week extra of physical activity for bicycle commuters versus motorized commuters. Among bicycle travelers, there was a positive dose-response relationship between bicycle commuting and physical activity duration, with an average extra physical activity duration of 0.5 (95% CI=0.4, 0.6) hours/week for every additional 1 hour/week of bicycle commuting. Bicycle commuting likely adds to overall physical activity. The extra physical activity performed by bicycle commuters is undertaken as moderate physical activity and follows a sigmoidal dose-response relationship with bicycle duration. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
A study of commuter airline economics
NASA Technical Reports Server (NTRS)
Summerfield, J. R.
1976-01-01
Variables are defined and cost relationships developed that describe the direct and indirect operating costs of commuter airlines. The study focused on costs for new aircraft and new aircraft technology when applied to the commuter airline industry. With proper judgement and selection of input variables, the operating costs model was shown to be capable of providing economic insight into other commuter airline system evaluations.
8 CFR 211.5 - Alien commuters.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 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 residence.... An alien commuter engaged in seasonal work will be presumed to have taken up residence in the United...
8 CFR 211.5 - Alien commuters.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 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 residence.... An alien commuter engaged in seasonal work will be presumed to have taken up residence in the United...
8 CFR 211.5 - Alien commuters.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 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 residence.... An alien commuter engaged in seasonal work will be presumed to have taken up residence in the United...
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...
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...
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…
Marginality of Transfer Commuter Students.
ERIC Educational Resources Information Center
Kodama, Corinne Maekawa
2002-01-01
Examines marginality issues facing transfer commuter students attending a mid-Atlantic university and what student characteristics relate to their sense of marginality. Results showed that transfer students have few sources of on-campus support, which may lead to their feelings of marginality. Results were particularly true for woman and Asian…
Non-commutativity in polar coordinates
NASA Astrophysics Data System (ADS)
Edwards, James P.
2017-05-01
We reconsider the fundamental commutation relations for non-commutative R2 described in polar coordinates with non-commutativity parameter θ . Previous analysis found that the natural transition from Cartesian coordinates to the traditional polar system led to a representation of [\\hat{r}, \\hat{φ}] as an everywhere diverging series. In this article we compute the Borel resummation of this series, showing that it can subsequently be extended throughout parameter space and hence provide an interpretation of this commutator. Our analysis provides a complete solution for arbitrary r and θ that reproduces the earlier calculations at lowest order and benefits from being generally applicable to problems in a two-dimensional non-commutative space. We compare our results to previous literature in the (pseudo-)commuting limit, finding a surprising spatial dependence for the coordinate commutator when θ ≫ r2. Finally, we raise some questions for future study in light of this progress.
Non-commutative Nash inequalities
Kastoryano, Michael; Temme, Kristan
2016-01-15
A set of functional inequalities—called Nash inequalities—are introduced and analyzed in the context of quantum Markov process mixing. The basic theory of Nash inequalities is extended to the setting of non-commutative L{sub p} spaces, where their relationship to Poincaré and log-Sobolev inequalities is fleshed out. We prove Nash inequalities for a number of unital reversible semigroups.
Non-commutative Nash inequalities
NASA Astrophysics Data System (ADS)
Kastoryano, Michael; Temme, Kristan
2016-01-01
A set of functional inequalities—called Nash inequalities—are introduced and analyzed in the context of quantum Markov process mixing. The basic theory of Nash inequalities is extended to the setting of non-commutative 𝕃p spaces, where their relationship to Poincaré and log-Sobolev inequalities is fleshed out. We prove Nash inequalities for a number of unital reversible semigroups.
Active commuting and habit strength: an interactive and discriminant analyses approach.
de Bruijn, Gert-Jan; Gardner, Benjamin
2011-01-01
Habits may be a mechanism linking environmental variables with active commuting. This study investigated the role of habit strength in the explanation of active commuting across profiles based on current active commuting, motivation, and habit strength within the framework of the theory of planned behavior (TPB). Cross-sectional survey using validated questionnaires. Undergraduate students who participated for course credits. Five hundred and thirty-eight students (mean age = 21.19 [SD = 2.57]; 28.45% males; response rate = 86.36%). Questionnaire included TPB items, underlying beliefs, and a validated measure of habit strength. Active commuting was assessed with relevant items from the International Physical Activity Questionnaire. Hierarchical regression and interaction analyses, discriminant function analysis, and analyses of variance. Habit strength was the strongest correlate of active commuting and interacted with intention: at low and medium levels of habit strength, the intention-bicycle use relationship was more than twice as strong as at high levels. Beliefs regarding situational barriers were amongst the most discriminating beliefs, whereas beliefs regarding health benefits did not distinguish profiles. Stronger active commuting habits are associated with a lower association between intention and bicycle use. Persuasive health campaigns might more usefully instill a sense of confidence in various commuting situations rather than merely emphasizing health benefits of active commuting.
Street lighting disturbs commuting bats.
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.
Happiness and Satisfaction with Work Commute.
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.
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.
New QCD sum rules based on canonical commutation relations
NASA Astrophysics Data System (ADS)
Hayata, Tomoya
2012-04-01
New derivation of QCD sum rules by canonical commutators is developed. It is the simple and straightforward generalization of Thomas-Reiche-Kuhn sum rule on the basis of Kugo-Ojima operator formalism of a non-abelian gauge theory and a suitable subtraction of UV divergences. By applying the method to the vector and axial vector current in QCD, the exact Weinberg’s sum rules are examined. Vector current sum rules and new fractional power sum rules are also discussed.
Detroit Commuter Hydrogen Project
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
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.
Wedge locality and asymptotic commutativity
NASA Astrophysics Data System (ADS)
Soloviev, M. A.
2014-05-01
In this paper, we study twist deformed quantum field theories obtained by combining the Wightman axiomatic approach with the idea of spacetime noncommutativity. We prove that the deformed fields with deformation parameters of opposite sign satisfy the condition of mutual asymptotic commutativity, which was used earlier in nonlocal quantum field theory as a substitute for relative locality. We also present an improved proof of the wedge localization property discovered for the deformed fields by Grosse and Lechner, and we show that the deformation leaves the asymptotic behavior of the vacuum expectation values in spacelike directions substantially unchanged.
Toronto bicycle commuter safety rates.
Aultman-Hall, L; Kaltenecker, M G
1999-11-01
This analysis uses data from a survey of Toronto commuter cyclists that collected information regarding accident history as well as regular commute route to work or school. By relating the route information of the 1196 respondents to facility attributes in a Geographic Information System (GIS), defensible estimates of travel exposure on roads, off-road paths and sidewalks were developed. The rate of collision on off-road paths and sidewalks was lower than for roads. The relative rates for falls and injuries suggest these events are least common on-road followed by off-road paths, and finally most common on sidewalks. The rate of major injuries, an injury that required medical attention, was greatest on sidewalks and the difference between paths and sidewalks was negligible. These rates suggest a need for detailed analysis of sidewalk and off-road path bicycle safety. The absolute event rates per bicycle kilometer were found to be between 26 and 68 times higher than similar rates for automobile travel, re-confirming the urgent bicycle safety crisis. Examination of rates for sub-groups of cyclists suggest that experience is an important factor in bicycle safety. The same survey conducted in Ottawa, Canada found event rates much lower than Toronto. This result may confirm urban form, traffic levels and attitude do affect bicycle safety. The analysis also demonstrates a successful method to quantify bicycle travel exposure information and should be considered for further use as complement to other existing techniques.
The relationship between bicycle commuting and perceived stress: a cross-sectional study
Avila-Palencia, Ione; de Nazelle, Audrey; Cole-Hunter, Tom; Donaire-Gonzalez, David; Jerrett, Michael; Rodriguez, Daniel A; Nieuwenhuijsen, Mark J
2017-01-01
Introduction Active commuting — walking and bicycling for travel to and/or from work or educational addresses — may facilitate daily, routine physical activity. Several studies have investigated the relationship between active commuting and commuting stress; however, there are no studies examining the relationship between solely bicycle commuting and perceived stress, or studies that account for environmental determinants of bicycle commuting and stress. The current study evaluated the relationship between bicycle commuting, among working or studying adults in a dense urban setting, and perceived stress. Methods A cross-sectional study was performed with 788 adults who regularly travelled to work or study locations (excluding those who only commuted on foot) in Barcelona, Spain. Participants responded to a comprehensive telephone survey concerning their travel behaviour from June 2011 through to May 2012. Participants were categorised as either bicycle commuters or non-bicycle commuters, and (based on the Perceived Stress Scale, PSS-4) as either stressed or non-stressed. Multivariate Poisson regression with robust variance models of stress status based on exposures with bicycle commuting were estimated and adjusted for potential confounders. Results Bicycle commuters had significantly lower risk of being stressed than non-bicycle commuters (Relative Risk; RR (95% CI)=0.73 (0.60 to 0.89), p=0.001). Bicycle commuters who bicycled 4 days per week (RR (95% CI)=0.42 (0.24 to 0.73), p=0.002) and those who bicycled 5 or more days per week (RR (95% CI)=0.57 (0.42 to 0.77), p<0.001) had lower risk of being stressed than those who bicycled less than 4 days. This relationship remained statistically significant after adjusting for individual and environmental confounders and when using different cut-offs of perceived stress. Conclusions Stress reduction may be an important consequence of routine bicycle use and should be considered by decision makers as another
The relationship between bicycle commuting and perceived stress: a cross-sectional study.
Avila-Palencia, Ione; de Nazelle, Audrey; Cole-Hunter, Tom; Donaire-Gonzalez, David; Jerrett, Michael; Rodriguez, Daniel A; Nieuwenhuijsen, Mark J
2017-06-23
Active commuting - walking and bicycling for travel to and/or from work or educational addresses - may facilitate daily, routine physical activity. Several studies have investigated the relationship between active commuting and commuting stress; however, there are no studies examining the relationship between solely bicycle commuting and perceived stress, or studies that account for environmental determinants of bicycle commuting and stress. The current study evaluated the relationship between bicycle commuting, among working or studying adults in a dense urban setting, and perceived stress. A cross-sectional study was performed with 788 adults who regularly travelled to work or study locations (excluding those who only commuted on foot) in Barcelona, Spain. Participants responded to a comprehensive telephone survey concerning their travel behaviour from June 2011 through to May 2012. Participants were categorised as either bicycle commuters or non-bicycle commuters, and (based on the Perceived Stress Scale, PSS-4) as either stressed or non-stressed. Multivariate Poisson regression with robust variance models of stress status based on exposures with bicycle commuting were estimated and adjusted for potential confounders. Bicycle commuters had significantly lower risk of being stressed than non-bicycle commuters (Relative Risk; RR (95% CI)=0.73 (0.60 to 0.89), p=0.001). Bicycle commuters who bicycled 4 days per week (RR (95% CI)=0.42 (0.24 to 0.73), p=0.002) and those who bicycled 5 or more days per week (RR (95% CI)=0.57 (0.42 to 0.77), p<0.001) had lower risk of being stressed than those who bicycled less than 4 days. This relationship remained statistically significant after adjusting for individual and environmental confounders and when using different cut-offs of perceived stress. Stress reduction may be an important consequence of routine bicycle use and should be considered by decision makers as another potential benefit of its promotion. © Article
Commutation failures in HVDC transmission systems
Thio, C.V.; Davies, J.B.; Kent, K.L.
1996-04-01
This paper provides a formulation for the initiation or onset mechanism of commutation failures in line-commutated thyristor converters, assuming infinite (zero impedance) ac systems. A theoretical development and a parametric analysis is given. Theory validation by simulation and comparison to actual field experience data is also given.
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…
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…
On non-commutative geodesic motion
NASA Astrophysics Data System (ADS)
Ulhoa, S. C.; Amorim, R. G. G.; Santos, A. F.
2014-07-01
In this work we study the geodesic motion on a noncommutative space-time. As a result we find a non-commutative geodesic equation and then we derive corrections of the deviation angle per revolution in terms of the non-commutative parameter when we specify the problem of Mercury's perihelion. In this way, we estimate the noncommutative parameter based in experimental data.
Is active commuting the answer to population health?
Shephard, Roy J
2008-01-01
This brief review examines whether active commuting is an effective method of controlling the current obesity epidemic and enhancing the cardiovascular health of the population. Of the many potential methods of active commuting, walking and cycling are the usual choices. Children and adolescents prefer cycling, but for adults issues of safety, cycle storage and company dress codes make walking the preferred option, particularly in North American cities, where urban design and weather conditions often do not favour cycling. Active transportation is more frequent in some European countries with dedicated cycle and pedestrian paths, but in most developed societies, active transportation has declined in recent years.Attempts to increase walking behaviour in the sedentary population have had only limited success to date. A weekly gross energy expenditure of at least 4 MJ is recommended to reduce all-cause and cardiovascular mortality. This can be achieved by walking 1.9 km in 22 minutes twice per day, 5 days per week, or by cycling at 16 km/h for 11 minutes twice per day, 5 days per week. When engaged in level walking, the intensity of effort may be adequate for cardiovascular benefit in older adults, but in fit young workers, it is necessary to either increase the pace or choose a hilly route in order to induce cardio-respiratory benefit; in contrast, cycling is likely to provide an adequate cardiovascular stimulus even for young adults.Empirical data to date have yielded mixed results: a reduced all-cause and cardiovascular mortality has been observed more frequently in cyclists than in walkers, and more frequently in women and older men than in young active commuters. More information is needed concerning the typical weekly dose of activity provided by active commuting, and the impact of such commuting on overall attitudes towards physical activity. It is also necessary to find better methods of involving the sedentary population, through both counselling and changes
Madeira, Marina Cordeiro; Siqueira, Fernando Carlos Vinholes; Facchini, Luiz Augusto; Silveira, Denise Silva da; Tomasi, Elaine; Thumé, Elaine; Silva, Suele Manjourany; Dilélio, Alitéia; Piccini, Roberto Xavier
2013-01-01
Evidence in the literature shows that physical activity associated with commuting (routine coming and going) can have a positive impact on health. The current study describes physical activity during commuting and some associated factors. A cross-sectional population-based study was conducted with 12,402 adults and 6,624 elderly in 100 municipalities (counties) from 23 States of Brazil. The outcome was based on the commuting section from the long version of the International Physical Activity Questionnaire (IPAQ). Prevalence of insufficient physical activity during commuting (< 150 minutes per week) was 66.6% in adults and 73.9% in the elderly. Among the elderly, the very old showed 25 times higher odds of being insufficiently active as compared to younger elders. Individuals with self-reported "white" skin color were less active in commuting. The findings show that prevalence of physical activity in commuting in Brazil is low, and that encouraging physically active commuting can be an effective strategy for increasing levels of physical activity and improving health.
Non-arcing commutation in explosive opening switches
NASA Astrophysics Data System (ADS)
Barber, John P.; Newman, Duane; Ford, Richard; Klug, Reja
1993-01-01
Explosively actuated opening switches can develop high impedance without arcing. We examine the commutation performance of the repetitively actuated pyrotechnic (RAP) switch in the USAF Armament Technology Battery Power System (ATBPS). The ATBPS stores over 10 MJ at up to 2.5 MA in an inductor. The RAP switch is used to commutate the current into a railgun load. The RAP switch develops several hundred volts before it completely opens and arcs. We have developed an analytic description of the nonarcing opening powers; it is primarily resistive, with current diffusion plays a central role. Experimental results which validate the theoretical model are also presented. The effect can be exploited to achieve higher nonarcing impedance, thereby reducing the destructive effects of arcs on the opening switch.
Advanced technologies applied to reduce the operating costs of small commuter transport aircraft
NASA Technical Reports Server (NTRS)
Masefield, O.; Turi, A.; Reinicke, M.
1982-01-01
The application of new aerodynamic, structural, and propulsion technologies to a specified baseline commuter aircraft is studied. The assessment models can be used on a desktop calculator and include a sizing program, operating cost program, and passenger ride qualities model. Evaluation is done with a step-by-step approach and is applied to range, number and type of engines, structure, wing selection, and configuration. A 40 percent direct operating cost saving is anticipated compared to current well established commuter aircraft.
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.
Fostering Formal Commutativity Knowledge with Approximate Arithmetic.
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.
Fostering Formal Commutativity Knowledge with Approximate Arithmetic
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
Efficient multiparty quantum key agreement protocol based on commutative encryption
NASA Astrophysics Data System (ADS)
Sun, Zhiwei; Huang, Jiwu; Wang, Ping
2016-05-01
A secure multiparty quantum key agreement protocol using single-qubit states is proposed. The agreement key is computed by performing exclusive-OR operation on all the participants' secret keys. Based on the commutative property of the commutative encryption, the exclusive-OR operation can be performed on the plaintext in the encrypted state without decrypting it. Thus, it not only protects the final shared key, but also reduces the complexity of the computation. The efficiency of the proposed protocol, compared with previous multiparty QKA protocols, is also improved. In the presented protocol, entanglement states, joint measurement and even the unitary operations are not needed, and only rotation operations and single-state measurement are required, which are easier to be realized with current technology.
Chiral bosonization for non-commutative fields
NASA Astrophysics Data System (ADS)
Das, Ashok; Gamboa, J.; Méndez, Fernando; López-Sarrión, Justo
2004-05-01
A model of chiral bosons on a non-commutative field space is constructed and new generalized bosonization (fermionization) rules for these fields are given. The conformal structure of the theory is characterized by a level of the Kac-Moody algebra equal to (1+theta2) where theta is the non-commutativity parameter and chiral bosons living in a non-commutative fields space are described by a rational conformal field theory with the central charge of the Virasoro algebra equal to 1. The non-commutative chiral bosons are shown to correspond to a free fermion moving with a speed equal to c' = c(1+theta2)1/2 where c is the speed of light. Lorentz invariance remains intact if c is rescaled by crightarrowc'. The dispersion relation for bosons and fermions, in this case, is given by omega = c'|k|.
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.
Opportunities and benefits. [commuter air travel
NASA Technical Reports Server (NTRS)
Galloway, T. L.
1983-01-01
The service characteristics and changes affecting commuter airline operations are summarized. Community and passenger considerations are addressed and the benefits identified in NASA-sponsored aircraft studies are discussed.
Corporate/commuter airlines meteorological requirements
NASA Technical Reports Server (NTRS)
Olcott, J. W.
1985-01-01
The meteorological information requirements of corporate and commuter airlines are reviewed. The skill level and needs of this class of aviator were assessed. An overview of the methodology by which meteorological data is communicated to these users is presented.
On nth commutativity degree of some 3-Engel groups
NASA Astrophysics Data System (ADS)
Yahya, Zainab; Mohd Ali, Nor Muhainiah; Sarmin, Nor Haniza; Sabani, Muhammad Syafiq; Zakaria, Mardhiah
2013-04-01
This paper focuses on some 3-Engel groups. Suppose x and y are elements of a group G. The commutativity degree of a group is the probability that two elements in the group commute and is denoted by P(G). Meanwhile, the nth commutativity degree of a group G is the probability that for any pairs of x and y in G, xn and y commute. In this paper, the nth commutativity degree of some 3-Engel groups is determined.
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.
Commuters and Parking at UNC-G. Preliminary Findings from the Commuting Student Survey.
ERIC Educational Resources Information Center
Reichard, Donald J.; McArver, Patricia P.
Data gleaned from items relating to transportation and parking from the Commuting Student Survey are reported. The survey questionnaire was designed to provide an overview of several aspects of the commuting student's relationship with the university and was sent to a stratified random sample of 2,140 students who were enrolled for the spring 1975…
Renormalisation des theories de champs non commutatives
NASA Astrophysics Data System (ADS)
Vignes-Tourneret, Fabien
2006-12-01
Very high energy physics needs a coherent description of the four fundamental forces. Non-commutative geometry is a promising mathematical framework which already allowed to unify the general relativity and the standard model, at the classical level, thanks to the spectral action principle. Quantum field theories on non-commutative spaces is a first step towards the quantification of such a model. These theories can't be obtained simply by writing usual field theory on non-commutative spaces. Such attempts exhibit indeed a new type of divergencies, called ultraviolet/infrared mixing, which prevents renormalisability. H. Grosse and R. Wulkenhaar showed, with an example, that a modification of the propagator may restore renormalisability. This thesis aims at studying the generalization of such a method. We studied two different models which allowed to specify certain aspects of non-commutative field theory. In x space, the major technical difficulty is due to oscillations in the interaction part. We generalized the results of T. Filk in order to exploit such oscillations at best. We were then able to distinguish between two mixings, renormalizable or not. We also bring the notion of orientability to light : the orientable non-commutative Gross-Neveu model is renormalizable without any modification of its propagator. The adaptation of multi-scale analysis to the matrix basis emphasized the importance of dual graphs and represents a first step towards a formulation of field theory independent of the underlying space.
Underlying mechanisms for commuting and migration processes
NASA Astrophysics Data System (ADS)
Simini, Filippo; Barabasi, Albert-Laszlo; Bagrow, James
2012-02-01
Both frequent commuting and long-term migration are complex human processes that strongly depend on socio-demographic, spatial, political, and even economic factors. We can describe both processes using weighted networks, in which nodes represent geographic locations and link weights denote the flux of individuals who commute (or migrate) between locations. Although both processes concern the movements of individuals, they are very different: commuting takes place on a daily (or weekly) basis and always between the same two locations, while migration is a rare, one-way displacement. Despite these differences, a recently proposed stochastic model, the Radiation model, provides evidence that both processes may be successfully described by the same underlying mechanism. For example, quantities of interest for either process, such as the distributions of trip length and destination populations, appear remarkably similar to the model's predictions. We explore the similarities and differences between commuting and migration both empirically, using census data for the United States, and theoretically, by comparing these commuting and migration networks to the predictions given by the Radiation model.
Commuting Distance, Cardiorespiratory Fitness, and Metabolic Risk
Hoehner, Christine M.; Barlow, Carolyn E.; Allen, Peg; Schootman, Mario
2012-01-01
Background Limited evidence exists on themetabolic and cardiovascul ar risk correlates of commuting by vehicle, a habitual form of sedentary behavior. Purpose To examine the association between commuting distance, physical activity, cardiorespiratory fitness (CRF), and metabolic risk indicators. Methods This cross-sectional study included 4297 adults who had a comprehensive medical examination between 2000 and 2007 and geocoded home and work addresses in 12 Texas metropolitan counties. Commuting distance was measured along the road network. Outcome variables included weekly MET-minutes of self-reported physical activity, CRF, BMI, waist circumference, triglycerides, plasma glucose, high-density lipoprotein (HDL) cholesterol, systolic and diastolic blood pressure, and continuously measured metabolic syndrome. Outcomes were also dichotomized using established cut-points. Linear and logistic regression models were adjusted for sociodemographic characteristics, smoking, alcohol intake, family history of diabetes, and history of high cholesterol, as well as BMI and weekly MET-minutes of physical activity and CRF (for BMI and metabolic risk models). Analyses were conducted in 2011. Results Commuting distance was negatively associated with physical activity and CRF and positively associated with BMI, waist circumference, systolic and diastolic blood pressure, and continuous metabolic score in fully adjusted linear regression models. Logistic regression analyses yielded similar associations; however, of the models with metabolic risk indicators as outcomes, only the associations with elevated blood pressure remained significant after adjustment for physical activity and CRF. Conclusions Commuting distance was adversely associated with physical activity, CRF, adiposity, and indicators of metabolic risk. PMID:22608372
Zhang, Xingyou; Holt, James B; Lu, Hua; Onufrak, Stephen; Yang, Jiawen; French, Steven P; Sui, Daniel Z
2014-02-01
Automobile dependency and longer commuting are associated with current obesity epidemic. We aimed to examine the urban-rural differential effects of neighborhood commuting environment on obesity in the US METHODS: The 1997-2005 National Health Interview Survey (NHIS) were linked to 2000 US Census data to assess the effects of neighborhood commuting environment: census tract-level automobile dependency and commuting time, on individual obesity status. Higher neighborhood automobile dependency was associated with increased obesity risk in urbanized areas (large central metro (OR 1.11[1.09, 1.12]), large fringe metro (OR 1.17[1.13, 1.22]), medium metro (OR 1.22[1.16, 1.29]), small metro (OR 1.11[1.04, 1.19]), and micropolitan (OR 1.09[1.00, 1.19])), but not in non-core rural areas (OR 1.00[0.92, 1.08]). Longer neighborhood commuting time was associated with increased obesity risk in large central metro (OR 1.09[1.04, 1.13]), and less urbanized areas (small metro (OR 1.08[1.01, 1.16]), micropolitan (OR 1.06[1.01, 1.12]), and non-core rural areas (OR 1.08[1.01, 1.17])), but not in (large fringe metro (OR 1.05[1.00, 1.11]), and medium metro (OR 1.04[0.98, 1.10])). The link between commuting environment and obesity differed across the regional urbanization levels. Urban and regional planning policies may improve current commuting environment and better support healthy behaviors and healthy community development. Copyright © 2013. Published by Elsevier Inc.
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.
Probing deformed commutators with macroscopic harmonic oscillators
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
Beating the traffic with commuting alternatives
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.
Commutability of food microbiology proficiency testing samples.
Abdelmassih, M; Polet, M; Goffaux, M-J; Planchon, V; Dierick, K; Mahillon, J
2014-03-01
Food microbiology proficiency testing (PT) is a useful tool to assess the analytical performances among laboratories. PT items should be close to routine samples to accurately evaluate the acceptability of the methods. However, most PT providers distribute exclusively artificial samples such as reference materials or irradiated foods. This raises the issue of the suitability of these samples because the equivalence-or 'commutability'-between results obtained on artificial vs. authentic food samples has not been demonstrated. In the clinical field, the use of noncommutable PT samples has led to erroneous evaluation of the performances when different analytical methods were used. This study aimed to provide a first assessment of the commutability of samples distributed in food microbiology PT. REQUASUD and IPH organized 13 food microbiology PTs including 10-28 participants. Three types of PT items were used: genuine food samples, sterile food samples and reference materials. The commutability of the artificial samples (reference material or sterile samples) was assessed by plotting the distribution of the results on natural and artificial PT samples. This comparison highlighted matrix-correlated issues when nonfood matrices, such as reference materials, were used. Artificially inoculated food samples, on the other hand, raised only isolated commutability issues. In the organization of a PT-scheme, authentic or artificially inoculated food samples are necessary to accurately evaluate the analytical performances. Reference materials, used as PT items because of their convenience, may present commutability issues leading to inaccurate penalizing conclusions for methods that would have provided accurate results on food samples. For the first time, the commutability of food microbiology PT samples was investigated. The nature of the samples provided by the organizer turned out to be an important factor because matrix effects can impact on the analytical results. © 2013
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)
A new inverter topology using GTO commutation
NASA Astrophysics Data System (ADS)
Rippel, W. E.
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.
On the non-commutative CP{sup 1} model
Lechtenfeld, Olaf; Maceda, Marco
2010-07-12
We present some results on the moduli space for the charge two-soliton solution of the non-commutative CP{sup 1} model. The associated Kaehler potential and its relation to the commutative case are discussed.
Real Structures on Almost-Commutative Spectral Triples
NASA Astrophysics Data System (ADS)
Ćaćić, Branimir
2013-07-01
We refine the reconstruction theorem for almost-commutative spectral triples to a result for real almost-commutative spectral triples, clarifying in the process both concrete and abstract definitions of real commutative and almost-commutative spectral triples. In particular, we find that a real almost-commutative spectral triple algebraically encodes the commutative *-algebra of the base manifold in a canonical way, and that a compact oriented Riemannian manifold admits real (almost-)commutative spectral triples of arbitrary KO-dimension. Moreover, we define a notion of smooth family of real finite spectral triples and of the twisting of a concrete real commutative spectral triple by such a family, with interesting KK-theoretic and gauge-theoretic implications.
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.…
26 CFR 1.46-11 - Commuter highway vehicles.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 26 Internal Revenue 1 2014-04-01 2013-04-01 true Commuter highway vehicles. 1.46-11 Section 1.46... Rules for Computing Credit for Investment in Certain Depreciable Property § 1.46-11 Commuter highway... investment under section 46(c)(1) for a qualifying commuter highway vehicle is 100 percent. A qualifying...
26 CFR 1.46-11 - Commuter highway vehicles.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 26 Internal Revenue 1 2011-04-01 2009-04-01 true Commuter highway vehicles. 1.46-11 Section 1.46... Rules for Computing Credit for Investment in Certain Depreciable Property § 1.46-11 Commuter highway... investment under section 46(c)(1) for a qualifying commuter highway vehicle is 100 percent. A qualifying...
The Impact Study of a Statcom on Commutation Failures in an HVDC Inverter Feeding a Weak AC System
NASA Astrophysics Data System (ADS)
Khatir, Mohamed; Zidi, Sid-Ahmed; Fellah, Mohammed-Karim; Hadjeri, Samir; Flitti, Mohamed
2012-03-01
The Static Synchronous Compensator (STATCOM) devices are pure power electronics devices that use voltage source, IGBT, IGCT or GTO based converters to generate reactive current. This paper illustrates the effect of STATCOM connected whit an HVDC inverter feeding a weak AC network, on the recovery from commutation failures following AC side disturbances. MATLAB/SIMULINK simulation results have demonstrated the robust performance of the proposed system based on the first CIGRÉ HVDC Benchmark model against commutation failures.
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.
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…
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.
Parsing and Generating English Using Commutative Transformations.
1982-05-01
AD-A1l? 4440 MASSACHUSETTS INST OF TECH CAMBRIDGE ARTIFICIAL INTE--ETC F/ G/7 PARSING AND GENERATING ENGLISH USING COMMUTATIVE TRANSFORMATION-EC MAT...English sentence, the auxiliary determines the form of the following verb: an infinitive follows a modal, the past participle follows HAVE, and the
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.
Commuter Students: References & Resources, 4th Edition.
ERIC Educational Resources Information Center
Taylor, Sharon L., Comp.; And Others
A bibliography of 505 references concerning commuter students is presented along with a list of 44 associations and organizations. Topics and the number of references on each topic (in parentheses) are as follows: adult learners/nontraditional students (63 references), community colleges (37) community/environmental impact (16), comparative…
The nth commutativity degree of some 2-Engel groups
NASA Astrophysics Data System (ADS)
Yahya, Zainab; Mohd Ali, Nor Muhainiah; Sarmin, Nor Haniza; Johari, Nor Azwin
2013-04-01
Suppose x and y are elements of a group G. The commutativity degree of a group G is defined as the total number of pair (x, y) for which x and y commute divided by the total number of pair (x, y) which is possible. Moreover, the nth commutativity degree of a group G is the total number of pair (x, y) for which xn and y commute divided by the total number of (x, y) which is possible. In this research, all 2-Engel groups of order at most 25 are first determined. Then, the nth commutativity degree of those groups are computed.
14 CFR 204.3 - Applicants for new certificate or commuter air carrier authority.
Code of Federal Regulations, 2011 CFR
2011-01-01
... applicant for a type of certificate authority it does not currently hold or for commuter air carrier... interest in the applicant are related by blood or marriage, such relationship(s) shall be included in the... description of the applicant's fleet of aircraft, including: (1) The number of each type of aircraft...
14 CFR 204.3 - Applicants for new certificate or commuter air carrier authority.
Code of Federal Regulations, 2014 CFR
2014-01-01
... applicant for a type of certificate authority it does not currently hold or for commuter air carrier... interest in the applicant are related by blood or marriage, such relationship(s) shall be included in the... description of the applicant's fleet of aircraft, including: (1) The number of each type of aircraft...
14 CFR 204.3 - Applicants for new certificate or commuter air carrier authority.
Code of Federal Regulations, 2013 CFR
2013-01-01
... applicant for a type of certificate authority it does not currently hold or for commuter air carrier... interest in the applicant are related by blood or marriage, such relationship(s) shall be included in the... description of the applicant's fleet of aircraft, including: (1) The number of each type of aircraft...
14 CFR 204.3 - Applicants for new certificate or commuter air carrier authority.
Code of Federal Regulations, 2012 CFR
2012-01-01
... applicant for a type of certificate authority it does not currently hold or for commuter air carrier... interest in the applicant are related by blood or marriage, such relationship(s) shall be included in the... description of the applicant's fleet of aircraft, including: (1) The number of each type of aircraft...
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.
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
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
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…
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…
Impact of commuting in epidemic invasion threshold
NASA Astrophysics Data System (ADS)
Balcan, Duygu; Vespignani, Alessandro
2010-03-01
Structured metapopulation models constitute one of the main approaches to the modeling of epidemic spread. While the contagion dynamics in each subpopulation is realized in a coarse-grained scheme, these models rely on the integration of multi-layered mobility data and accurate representations of human movements in different scales. Different scales are not just embedded in the spatial component of the process (long-range versus short-range movements) but also in the duration of the trips (long versus short visits). In this context, commuting, the daily movement of people between home and workplace or home and school, is one of the essential ingredients in multi-scale mobility networks. We consider an SIR-epidemic in a metapopulation system whose subpopulations are coupled by commuting. We investigate analytically and numerically the global epidemic invasion threshold.
Commuting behaviors and exposure to air pollution in Montreal, Canada.
Miao, Qun; Bouchard, Michèle; Chen, Dongmei; Rosenberg, Mark W; Aronson, Kristan J
2015-03-01
Vehicular traffic is a major source of outdoor air pollution in urban areas, and studies have shown that air pollution is worse during hours of commuting to and from work and school. However, it is unclear to what extent different commuting behaviors are a source of air pollution compared to non-commuters, and if air pollution exposure actually differs by the mode of commuting. This study aimed to examine the relationships between commuting behaviors and air pollution exposure levels measured by urinary 1-OHP (1-hydroxypyrene), a biomarker of exposure to polycyclic aromatic hydrocarbons (PAHs). A cross-sectional study of 174 volunteers living in Montreal, 92 females and 82 males, aged 20 to 53 years was conducted in 2011. Each participant completed a questionnaire regarding demographic factors, commuting behaviors, home and workplace addresses, and potential sources of PAH exposure, and provided a complete first morning void urine sample for 1-OHP analysis. Multivariable general linear regression models were used to examine the relationships between different types of commuting and urinary 1-OHP levels. Compared to non-commuters, commuters traveling by foot or bicycle and by car or truck had a significantly higher urinary 1-OHP concentration in urine (p=0.01 for foot or bicycle vs. non-commuters; p=0.02 for car or truck vs. non-commuters); those traveling with public transportation and combinations of two or more types of modes tended to have an increased 1-OHP level in urine (p=0.06 for public transportation vs. non-commuters; p=0.05 for commuters with combinations of two or more types of modes vs. non-commuters). No significant difference in urinary 1-OHP variation was found by mode of commuting. This preliminary study suggests that despite the mode of commuting, all types of commuting during rush hours increase exposure to air pollution as measured by a sensitive PAH metabolite biomarker, and mode of commuting did not explain exposure variation. Copyright
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.
Delayed Commutation in Quantum Computer Networks
NASA Astrophysics Data System (ADS)
García-Escartín, Juan Carlos; Chamorro-Posada, Pedro
2006-09-01
In the same way that classical computer networks connect and enhance the capabilities of classical computers, quantum networks can combine the advantages of quantum information and communication. We propose a nonclassical network element, a delayed commutation switch, that can solve the problem of switching time in packet switching networks. With the help of some local ancillary qubits and superdense codes, we can route a qubit packet after part of it has left the network node.
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.
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.
Classical mechanics in non-commutative phase space
NASA Astrophysics Data System (ADS)
Wei, Gao-Feng; Long, Chao-Yun; Long, Zheng-Wen; Qin, Shui-Jie; Fu, Qiang
2008-05-01
In this paper the laws of motion of classical particles have been investigated in a non-commutative phase space. The corresponding non-commutative relations contain not only spatial non-commutativity but also momentum non-commutativity. First, new Poisson brackets have been defined in non-commutative phase space. They contain corrections due to the non-commutativity of coordinates and momenta. On the basis of this new Poisson brackets, a new modified second law of Newton has been obtained. For two cases, the free particle and the harmonic oscillator, the equations of motion are derived on basis of the modified second law of Newton and the linear transformation (Phys. Rev. D, 2005, 72: 025010). The consistency between both methods is demonstrated. It is shown that a free particle in commutative space is not a free particle with zero-acceleration in the non-commutative phase space, but it remains a free particle with zero-acceleration in non-commutative space if only the coordinates are non-commutative. Supported by National Natural Science Foundation of China (10347003, 60666001), Planned Training Excellent Scientific and Technological Youth Foundation of Guizhou Province, China (2002,2013), Science Foundation of Guizhou Province, China, and Creativity Foundation for Graduate Guizhou University, China (2006031)
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
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 = ∞.
Battery cars on superconducting magnetically levitated carriers: One commuting solution
NASA Astrophysics Data System (ADS)
Briggs, B. Mike; Oman, Henry
1992-05-01
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.
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.
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.
Hawking-Moss tunneling in non-commutative eternal inflation
Cai Yifu; Wang Yi E-mail: wangyi@itp.ac.cn
2008-01-15
The quantum behavior of non-commutative eternal inflation is quite different from the usual scenario. Unlike the usual eternal inflation, non-commutative eternal inflation has quantum fluctuation suppressed by the Hubble parameter. Because of this, we need to reconsider many conceptions of eternal inflation. In this paper we study the Hawking-Moss tunneling in non-commutative eternal inflation using the stochastic approach. We obtain a brand new form of tunneling probability for this process and find that the Hawking-Moss tunneling is more unlikely to take place in the non-commutative case than in the usual one. We also conclude that the lifetime of a metastable de Sitter vacuum in the non-commutative spacetime is longer than that in the commutative case.
Dirac Oscillator in a Galilean Covariant Non-commutative Space
NASA Astrophysics Data System (ADS)
de Melo, G. R.; de Montigny, M.; Pompeia, P. J.; Santos, E. S.
2013-02-01
We study the Galilean Dirac oscillator in a non-commutative situation, with space-space and momentum-momentum non-commutativity. The wave equation is obtained via a `Galilean covariant' approach, which consists in projecting the covariant equations from a (4,1)-dimensional manifold with light-cone coordinates, to a (3,1)-dimensional Galilean space-time. We obtain the exact wave functions and their energy levels for the plane and discuss the effects of non-commutativity.
Blocks in cycles and k-commuting permutations.
Moreno, Rutilo; Rivera, Luis Manuel
2016-01-01
We introduce and study k-commuting permutations. One of our main results is a characterization of permutations that k-commute with a given permutation. Using this characterization, we obtain formulas for the number of permutations that k-commute with a permutation [Formula: see text], for some cycle types of [Formula: see text]. Our enumerative results are related with integer sequences in "The On-line Encyclopedia of Integer Sequences", and in some cases provide new interpretations for such sequences.
Commuting by car: weight gain among physically active adults.
Sugiyama, Takemi; Ding, Ding; Owen, Neville
2013-02-01
Prolonged sitting, including time spent sitting in cars, is detrimentally associated with health outcomes. This study examined whether commuting by car was associated with adults' weight gain over 4 years. Among 822 adult residents of Adelaide, Australia, weight change was ascertained from self-reported weight at baseline (2003-2004) and at follow-up (2007-2008). Using time spent for car commuting and work status at baseline, participants were categorized as non-car commuters, occasional car commuters, and daily car commuters. Multilevel linear regression (conducted in 2012) examined associations of weight change with car-commuting category, adjusting for potential confounding variables, for the whole sample, and among those who were physically inactive or active (≥150 minutes/week) in their leisure time. For the overall sample, adjusted mean weight gain (95% CI) over 4 years was 1.26 (0.64, 1.89) kg for non-car commuters; 1.53 (0.69, 2.37) kg for occasional car commuters; and 2.18 (1.44, 2.92) kg for daily car commuters (p for trend=0.090). Stratified analyses found a stronger association for those with sufficient leisure-time physical activity. For non-car commuters with sufficient leisure-time physical activity, the adjusted mean weight gain was 0.46 (-0.43, 1.35) kg, which was not significantly greater than 0. Over 4 years, those who used cars daily for commuting tended to gain more weight than those who did not commute by car. This relationship was pronounced among those who were physically active during leisure time. Reducing sedentary time may prevent weight gain among physically active adults. Copyright © 2013 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
A video based feedback system for control of an active commutator during behavioral physiology.
Roh, Mootaek; McHugh, Thomas J; Lee, Kyungmin
2015-10-12
To investigate the relationship between neural function and behavior it is necessary to record neuronal activity in the brains of freely behaving animals, a technique that typically involves tethering to a data acquisition system. Optimally this approach allows animals to behave without any interference of movement or task performance. Currently many laboratories in the cognitive and behavioral neuroscience fields employ commercial motorized commutator systems using torque sensors to detect tether movement induced by the trajectory behaviors of animals. In this study we describe a novel motorized commutator system which is automatically controlled by video tracking. To obtain accurate head direction data two light emitting diodes were used and video image noise was minimized by physical light source manipulation. The system calculates the rotation of the animal across a single trial by processing head direction data and the software, which calibrates the motor rotation angle, subsequently generates voltage pulses to actively untwist the tether. This system successfully provides a tether twist-free environment for animals performing behavioral tasks and simultaneous neural activity recording. To the best of our knowledge, it is the first to utilize video tracking generated head direction to detect tether twisting and compensate with a motorized commutator system. Our automatic commutator control system promises an affordable and accessible method to improve behavioral neurophysiology experiments, particularly in mice.
Campus Commuters: A Survey of the Service Needs of Commuter Students at the University of Minnesota.
ERIC Educational Resources Information Center
Matross, Ron; And Others
1984-01-01
Service-related needs and behaviors of University of Minnesota-Twin Cities students were surveyed in 1981. Based on responses of 2,112 students in selected classes, it was found that 81 percent of the respondents were commuters. Approximately 32 percent said they were not at all involved in campus life, while about 47 percent were only slightly…
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
Satisfaction with transport and enjoyment of the commute by commuting mode in inner Sydney.
Rissel, Chris; Crane, Melanie; Wen, Li Ming; Greaves, Stephen; Standen, Chris
2016-04-01
Issue addressed Travel satisfaction has become an increasingly popular construct for the assessment and monitoring of transport systems and services. However, satisfaction may not adequately assess emotion or mood towards walking and cycling, especially when infrastructure is biased towards motor vehicle modes. In this exploratory study we sought to examine the associations of both satisfaction with transport and enjoyment from the commute to work or study by commute mode in an Australian inner city context where transport mode choices are readily available. Methods As part of the Sydney Transport and Health Study, 675 baseline study participants (2013) were invited to complete an online questionnaire in September/October 2014 and 512 did so (76% response rate). Participants who did not travel to work were removed from analyses, giving complete data for 473. Participants provided data on usual travel mode to work or study, satisfaction with transport, enjoyment from their commute, and demographics and neighbourhood factors. Results The main mode of travel to work or study in this inner city sample was public transport (41%), followed by motor vehicle (27%), walking (21%) and cycling (10%). Most participants were satisfied with their transport (82%), with little variation by mode. Walkers (49%) and cyclists (52%) reported far higher levels of enjoyment from their commute than car drivers (14%) or public transport users (10%), with an adjusted odds ratio of 6.18 (95% confidence interval 3.10-12.29, P<0.001) for walking and an adjusted odds ratio of 6.15 (95% confidence interval 2.68-14.08, P<0.001) for cycling. Conclusions People who walked or cycled to work or study in inner Sydney reported higher levels of enjoyment from their commute compared with those who drove. This suggests enjoyment may be another benefit of active travel. So what? Focusing on 'enjoyment' associated with walking or cycling to work may be a positive motivator to encourage active travel.
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.
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.
Bicycle weight and commuting time: randomised trial
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
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…
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…
Impact of commuter-rail services in Toronto region
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.
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…
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.
Parity-dependent non-commutative quantum mechanics
NASA Astrophysics Data System (ADS)
Chung, Won Sang
2017-01-01
In this paper, we consider the non-commutative quantum mechanics (NCQM) with parity (or space reflection) in two dimensions. Using the parity operators Ri, we construct the deformed Heisenberg algebra with parity in the non-commutative plane. We use this algebra to discuss the isotropic harmonic Hamiltonian with parity.
Weather factor impacts on commuting to work by bicycle.
Flynn, Brian S; Dana, Greg S; Sears, Justine; Aultman-Hall, Lisa
2012-02-01
Quantify the impact of weather conditions on individual decisions to commute to work by bicycle among a diverse panel of adults who commute ≥2 miles each way. Working adults (n=163) in a northern U.S. state reported transportation mode for four seven-day periods in 2009-2010 that maximized seasonal weather variations. Personal characteristics, trip to work distances, and commuting mode data were linked to location- and time-specific weather data and daylight hours. Analyses focused on effect of weather conditions on reports of commuting by bicycle. Participants were diverse in age, gender and bicycle use, but were relatively well-educated; they traveled to work by bicycle on 34.5% of the logged commuting days. Modeling indicated that the likelihood of bicycle commuting increased in the absence of rain (odds ratio=1.91; 95% confidence interval 1.42, 2.57) and with higher temperatures (1.03; 1.02, 1.04), and decreased with snow (0.90; 0.84, 0.98) and wind (0.95; 0.92, 0.97). Independent effects also were found for bicycle commuting distance, gender, and age, but not for daylight hours. Precipitation, temperature, wind and snow conditions had significant and substantial independent effects on the odds of travel to work by bicycle among a diverse panel of adult bicycle commuters. Copyright © 2011 Elsevier Inc. All rights reserved.
Parabosonic string and space-time non-commutativity
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.
Non-commutative relativistic equation with a Coulomb potential
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.
The Neglected Majority: Facilities for Commuting Students. A Report.
ERIC Educational Resources Information Center
Educational Facilities Labs., Inc., New York, NY.
Commuting students enrolled in colleges and universities outnumber their residential counterparts by about three to one. Studies and surveys reveal that the expectations of commuting students are modest and convential. Often they can be satisfied without a great capital investment, by reallocating existing resources, renovating space and making…
Self-adjoint commuting differential operators of rank two
NASA Astrophysics Data System (ADS)
Mironov, A. E.
2016-08-01
This is a survey of results on self-adjoint commuting ordinary differential operators of rank two. In particular, the action of automorphisms of the first Weyl algebra on the set of commuting differential operators with polynomial coefficients is discussed, as well as the problem of constructing algebro-geometric solutions of rank l>1 of soliton equations. Bibliography: 59 titles.
26 CFR 1.46-11 - Commuter highway vehicles.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 26 Internal Revenue 1 2013-04-01 2013-04-01 false Commuter highway vehicles. 1.46-11 Section 1.46... vehicles. (a) In general. Section 46(c)(6) provides that the applicable percentage to determine qualified investment under section 46(c)(1) for a qualifying commuter highway vehicle is 100 percent. A...
26 CFR 1.46-11 - Commuter highway vehicles.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 26 Internal Revenue 1 2012-04-01 2012-04-01 false Commuter highway vehicles. 1.46-11 Section 1.46... vehicles. (a) In general. Section 46(c)(6) provides that the applicable percentage to determine qualified investment under section 46(c)(1) for a qualifying commuter highway vehicle is 100 percent. A...
Current Fire Safety Design Aspects of Commuter Aircraft.
1988-03-01
or MIL-W- 81044/9. Shielded stranded wire of MIL-C-7078B Class 4 or MIL-C-27500. Teflon insulated or high temperature stranded wire of MIL-W- 22759 /7...MIL-W- 22759 /8, MIL-W-25038, MILSPEC 17411, or MIL-W-16878D Type E. MIL-W-16878D Type E wire is not to be used in any harness which is supported by...insulated or high temperature stranded wire of MIL-W- 22759 /7, MIL-W- 22759 /8, MIL-W-250389 MILSPEC 17411, or MIL-W-16878D Type E. MIL-W-16878D Type E wire
77 FR 45715 - Application of Key Lime Air Corporation for Commuter Authority
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-01
...] Application of Key Lime Air Corporation for Commuter Authority AGENCY: Department of Transportation. ACTION... Lime Air Corporation fit, willing, and able, and awarding it a Commuter Air Carrier...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-12
..., Supplemental, Commuter, and On-Demand Operations: Corrections and Editorial Changes AGENCY: Federal Aviation... Requirements: Domestic, Flag, Supplemental, Commuter, and On-Demand Operations: Corrections and Editorial...
Extended commuting and migration in the Taipei metropolitan area.
Chen, C
1992-12-01
The aim of this study was to examine the relationship between the relative size and extent of labor force commuting and migration among the population 15 years and older in the Taipei, Taiwan, metropolitan area (city, periphery, and other areas), and the variation by labor group. The hypothesis was that extended commuting patterns occur before migration and migrants and commuters come from different groups. There was a well-developed transportation system for long commuters. It was also suspected that commuting and migration were alternatives for each other, because of the long commutes (over 40 minutes) and the young, unmarried age groups associated with migration. Data were obtained from a stratified sample from the October round of the labor force survey in 1988. Data were stratified by degree of urbanization and industrial composition, and within village level units. The migration streams were identified as from Taipei periphery to the city, from other areas to the city, from the city to the periphery, from other areas to the periphery, from the city to other areas, and from the periphery to other areas. Commuter patterns were designated by commuting from the city to the periphery, from the city to other areas, from the periphery to the city, from the periphery to other areas, from other areas to the city, and from other areas to the periphery. The sample population of 8,384,587 was greater than the official estimates by 3.4%. In the weighted sample, 13.5% were missing data, which resulted in an employed population of 1,271,309 persons. The trend has been for stability of population growth of 2% in the city, and a decline to a rate of growth of 1.3% in peripheral areas. Both the city and periphery gained population from other areas: 70,000 and 35,000 persons, respectively; there was a balanced stream between the city and periphery of 30,000 persons. 24.1% of periphery workers were commuters to the city with a commuting population of 250,000 daily. Explanations
Spontaneous Usage of Different Shortcuts Based on the Commutativity Principle
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
Perfect commuting-operator strategies for linear system games
NASA Astrophysics Data System (ADS)
Cleve, Richard; Liu, Li; Slofstra, William
2017-01-01
Linear system games are a generalization of Mermin's magic square game introduced by Cleve and Mittal. They show that perfect strategies for linear system games in the tensor-product model of entanglement correspond to finite-dimensional operator solutions of a certain set of non-commutative equations. We investigate linear system games in the commuting-operator model of entanglement, where Alice and Bob's measurement operators act on a joint Hilbert space, and Alice's operators must commute with Bob's operators. We show that perfect strategies in this model correspond to possibly infinite-dimensional operator solutions of the non-commutative equations. The proof is based around a finitely presented group associated with the linear system which arises from the non-commutative equations.
Effects of urban growth controls on intercity commuting.
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.
A double commutant theorem for Murray–von Neumann algebras
Liu, Zhe
2012-01-01
Murray–von Neumann algebras are algebras of operators affiliated with finite von Neumann algebras. In this article, we study commutativity and affiliation of self-adjoint operators (possibly unbounded). We show that a maximal abelian self-adjoint subalgebra of the Murray–von Neumann algebra associated with a finite von Neumann algebra is the Murray–von Neumann algebra , where is a maximal abelian self-adjoint subalgebra of and, in addition, is . We also prove that the Murray–von Neumann algebra with the center of is the center of the Murray–von Neumann algebra . Von Neumann’s celebrated double commutant theorem characterizes von Neumann algebras as those for which , where , the commutant of , is the set of bounded operators on the Hilbert space that commute with all operators in . At the end of this article, we present a double commutant theorem for Murray–von Neumann algebras. PMID:22543165
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.
Manohar, P.; Chandrasekharaiah, H.S. . Dept. of High Voltage Engineering)
1991-02-01
The dynamic analysis of a mesh type multiterminal HVDC (MTDC) transmission system including an artificially commutated inverted (ACI) with varistor protected series capacitors is carried out using digital simulation technique. The study shows that the varistor protection is feasible and improves the performance of normal rated inverters which connect weak ac systems. It reduces the magnitude of dynamic overvoltage and the peak direct current at the ACI during abnormal conditions resulting in a significantly improved dynamic performance of the MTDC system.
Electric-vehicle commuter car battery requirements
Harbaugh, D.L.
1994-12-31
In order for the battery-powered commuter car to become a realistic transportation alternative to the gasoline-powered vehicle, it must be capable of being safely integrated with existing traffic; have sufficient range to accomplish the driver`s mission objectives; be competitively priced in initial cost, cost per mile, and total life-cycle cost, and be convenient to use and inexpensive to maintain. The electric vehicle drive system is inherently less complicated than the conventional internal-combustion engine vehicle and should be less expensive when produced in the same quantities. The Achilles heel of the electric vehicle (EV) is, therefore, the battery, which is the subject of this paper. 1 ref.
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.
A non-commuting stabilizer formalism
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.
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.
Commutation Relations and Discrete Garnier Systems
NASA Astrophysics Data System (ADS)
Ormerod, Christopher M.; Rains, Eric M.
2016-11-01
We present four classes of nonlinear systems which may be considered discrete analogues of the Garnier system. These systems arise as discrete isomonodromic deformations of systems of linear difference equations in which the associated Lax matrices are presented in a factored form. A system of discrete isomonodromic deformations is completely determined by commutation relations between the factors. We also reparameterize these systems in terms of the image and kernel vectors at singular points to obtain a separate birational form. A distinguishing feature of this study is the presence of a symmetry condition on the associated linear problems that only appears as a necessary feature of the Lax pairs for the least degenerate discrete Painlevé equations.
Eulerian Dynamics with a Commutator Forcing
2017-01-09
class of L’s which are neither positive nor bounded. We have three typical examples in mind . 1.1. Examples. Consider L = Lφ of the form (1.4) Lφ(f)(x...1.1),(1.2) reads , (1.9) { ρt + (ρu)x = 0, (ρu)t + (ρu 2)x = ρL(ρu)− ρL(ρ)u, (x, t) ∈ Ω× R+. We shall make a detailed study on the propagation of...a priori control estimates via e. The study of global well-posedness for all three cases of commutator forcing we have in mind — bounded, sin- gular
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.
Particle Physics from Almost-Commutative Spacetimes
NASA Astrophysics Data System (ADS)
van den Dungen, Koen; van Suijlekom, Walter D.
2012-10-01
Our aim in this review paper is to present the applications of Connes' noncommutative geometry to elementary particle physics. Whereas the existing literature is mostly focused on a mathematical audience, in this paper we introduce the ideas and concepts from noncommutative geometry using physicists' terminology, gearing towards the predictions that can be derived from the noncommutative description. Focusing on a light package of noncommutative geometry (so-called "almost-commutative manifolds"), we shall introduce in steps: electrodynamics, the electroweak model, culminating in the full Standard Model. We hope that our approach helps in understanding the role noncommutative geometry could play in describing particle physics models, eventually unifying them with Einstein's (geometrical) theory of gravity.
Physical activity during leisure and commuting in Tianjin, China.
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
Commuting behavior of western U.S. residents
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.
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.
On Spaces of Commuting Elements in Lie Groups
2014-02-25
rank isotropy. J. Topol., 5(2):431–457, 2012. [9] T. Baird. Cohomology of the space of commuting n-tuples in a compact Lie group. Algebr . Geom. Topol...ON SPACES OF COMMUTING ELEMENTS IN LIE GROUPS By Frederick R. Cohen and Mentor Stafa with an appendix by V. Reiner IMA Preprint...2014 to 00-00-2014 4. TITLE AND SUBTITLE On Spaces of Commuting Elements in Lie Groups 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT
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...
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...
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...
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...
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...
Experimental investigations on arc movement and commutation in the Low-Voltage Circuit Breaker
NASA Astrophysics Data System (ADS)
Quéméneur, Jean; Masquère, Mathieu; Freton, Pierre; Gonzalez, Jean-Jacques; Joyeux, Patrice
2017-04-01
Displacement of an electrical arc between two parallel arc runners is studied with high-speed imaging, voltage, current and pressure measurements. The experimental set-up is detailed from the current source to the post-treatment methods. The influence of intensity, gas exhausts and volume behind the moving contact on arc commutation and movement are investigated. In the context of Low-Voltage Circuit Breaker (LVCB), it is shown that for high-intensity arcs, evacuating the hot gas is necessary for a good motion of the arc. Furthermore, a configuration of exhaust allowing a quick movement will not work for all current levels.
Southern Nevadas Club Ride Commuter Service Wins EPA Honor
Â· Clean Air Partners Program - CLEAN AIR Force of Central Texas Â· Club Ride Commuter Services - Regional Transportation Commission of Southern Nevada Â· Air Quality Partnership of the Delaware Valley - Delaware Valley Regional Planning
75 FR 13680 - Commutation of Sentence: Technical Change
Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-23
... commutation order. However, in 2005, the Bureau centralized its designation and sentence computation functions... economy of $100,000,000 or more; a major increase in costs or prices; or significant adverse effects on...
Leptogenesis from a Non Commutative FRW Like Model
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.
Strong Planck constraints on braneworld and non-commutative inflation
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.
Classical limits of quantum mechanics on a non-commutative configuration space
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.
What interventions increase commuter cycling? A systematic review
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
Non-commutativity and Local Indistinguishability of Quantum States
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
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.
Quantum walled Brauer algebra: commuting families, Baxterization, and representations
NASA Astrophysics Data System (ADS)
Semikhatov, A. M.; Tipunin, I. Yu
2017-02-01
For the quantum walled Brauer algebra, we construct its Specht modules and (for generic parameters of the algebra) seminormal modules. The latter construction yields the spectrum of a commuting family of Jucys-Murphy elements. We also propose a Baxterization prescription; it involves representing the quantum walled Brauer algebra in terms of morphisms in a braided monoidal category and introducing parameters into these morphisms, which allows constructing a ‘universal transfer matrix’ that generates commuting elements of the algebra.
Aerodynamically balanced ailerons for a commuter aircraft
NASA Astrophysics Data System (ADS)
Soinne, Erkki
2001-08-01
This review paper describes the state of designing aerodynamically balanced ailerons with a practical application to commuter aircraft, with Saab 2000 being used as an example. A modern design method is presented based on the application of CFD computations to determine the aileron aerodynamic data combined with flight mechanical simulations to study the impact on airplane rolling maneuvers and aileron dynamics. Dynamic response of aileron deflection, airplane roll rate and roll acceleration to the applied wheel force is determined by frequency analysis. A review on the design requirements on ailerons and practical design considerations is presented. The CFD computations are described in detail with comparisons against wind tunnel experiments and flight tests for validation of the methodology. Description of the flight mechanical simulation system includes the modeling of the aileron control system. The frequency analysis summarizes the equations of the employed Fourier analysis, spectrum analysis and system identification. Numerical results are presented on aileron hinge moment coefficient, airplane rolling moment coefficient, wheel force in sideslip and rolling maneuvers and gain and phase lag in frequency analysis results to highlight the key discussion points including the effects of aileron control system and aileron and tab gap sizes. Overall, aerodynamically balanced ailerons, together with a mechanical control system, offer large cost savings on small- and medium-sized airplanes.
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
Active Commuting among K-12 Educators: A Study Examining Walking and Biking to Work
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
Bias Assessment of General Chemistry Analytes using Commutable Samples.
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.
A double commutant theorem for Murray-von Neumann algebras.
Liu, Zhe
2012-05-15
Murray-von Neumann algebras are algebras of operators affiliated with finite von Neumann algebras. In this article, we study commutativity and affiliation of self-adjoint operators (possibly unbounded). We show that a maximal abelian self-adjoint subalgebra A of the Murray-von Neumann algebra A(f)(R) associated with a finite von Neumann algebra R is the Murray-von Neumann algebra A(f)(A(0)), where A(0) is a maximal abelian self-adjoint subalgebra of R and, in addition, A(0) is A Π R. We also prove that the Murray-von Neumann algebra A(f)(C) with C the center of R is the center of the Murray-von Neumann algebra A(f)(R). Von Neumann's celebrated double commutant theorem characterizes von Neumann algebras R as those for which R'' = R, where R', the commutant of R, is the set of bounded operators on the Hilbert space that commute with all operators in R. At the end of this article, we present a double commutant theorem for Murray-von Neumann algebras.
Bias Assessment of General Chemistry Analytes using Commutable Samples
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
2014-01-01
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. PMID:25678726
Local discrimination of qudit lattice states via commutativity
NASA Astrophysics Data System (ADS)
Tian, Guojing; Yu, Sixia; Gao, Fei; Wen, Qiaoyan; Oh, C. H.
2015-10-01
Qudit lattice states, as the generalization of qubit lattice states, are the maximally entangled states determined by qudit lattice unitaries in a pr⊗pr quantum system with p being a prime and r being an integer. Based on the partitions of qudit lattice unitaries into commuting sets, we present a sufficient condition for local discrimination of qudit lattice states, in which the commutativity plays an efficient role. It turns out that any set of l qudit lattice states with 2 ≤l ≤pr , including k ≤l mutually commuting qudit lattice unitaries and satisfying l (l -1 ) -(k +1 ) (k -2 ) ≤2 pr , can be locally distinguished, not only extending Fan's result [H. Fan, Phys. Rev. Lett. 92, 177905 (2004), 10.1103/PhysRevLett.92.177905] to the prime power quantum system but also involving the local discrimination of a larger number of maximally entangled states.
McMinn, David; Rowe, David A; Murtagh, Shemane; Nelson, Norah M
2012-05-01
To investigate the effect of a school-based intervention called Travelling Green (TG) on children's walking to and from school and total daily physical activity. A quasi-experiment with 166 Scottish children (8-9 years) was conducted in 2009. One group (n=79) received TG and another group (n=87) acted as a comparison. The intervention lasted 6 weeks and consisted of educational lessons and goal-setting tasks. Steps and MVPA (daily, a.m. commute, p.m. commute, and total commute) were measured for 5 days pre- and post-intervention using accelerometers. Mean steps (daily, a.m., p.m., and total commute) decreased from pre- to post-intervention in both groups (TG by 901, 49, 222, and 271 steps/day and comparison by 2528, 205, 120, and 325 steps/day, respectively). No significant group by time interactions were found for a.m., p.m., and total commuting steps. A medium (partial eta squared=0.09) and significant (p<0.05) group by time interaction was found for total daily steps. MVPA results were similar to step results. TG has a little effect on walking to and from school. However, for total daily steps and daily MVPA, TG results in a smaller seasonal decrease than for children who do not receive the intervention. Copyright © 2012 Elsevier Inc. All rights reserved.
Quantum dynamics of simultaneously measured non-commuting observables
NASA Astrophysics Data System (ADS)
Hacohen-Gourgy, Shay; Martin, Leigh S.; Flurin, Emmanuel; Ramasesh, Vinay V.; Whaley, K. Birgitta; Siddiqi, Irfan
2016-10-01
In quantum mechanics, measurements cause wavefunction collapse that yields precise outcomes, whereas for non-commuting observables such as position and momentum Heisenberg’s uncertainty principle limits the intrinsic precision of a state. Although theoretical work has demonstrated that it should be possible to perform simultaneous non-commuting measurements and has revealed the limits on measurement outcomes, only recently has the dynamics of the quantum state been discussed. To realize this unexplored regime, we simultaneously apply two continuous quantum non-demolition probes of non-commuting observables to a superconducting qubit. We implement multiple readout channels by coupling the qubit to multiple modes of a cavity. To control the measurement observables, we implement a ‘single quadrature’ measurement by driving the qubit and applying cavity sidebands with a relative phase that sets the observable. Here, we use this approach to show that the uncertainty principle governs the dynamics of the wavefunction by enforcing a lower bound on the measurement-induced disturbance. Consequently, as we transition from measuring identical to measuring non-commuting observables, the dynamics make a smooth transition from standard wavefunction collapse to localized persistent diffusion and then to isotropic persistent diffusion. Although the evolution of the state differs markedly from that of a conventional measurement, information about both non-commuting observables is extracted by keeping track of the time ordering of the measurement record, enabling quantum state tomography without alternating measurements. Our work creates novel capabilities for quantum control, including rapid state purification, adaptive measurement, measurement-based state steering and continuous quantum error correction. As physical systems often interact continuously with their environment via non-commuting degrees of freedom, our work offers a way to study how notions of contemporary
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.
The judgement of simultaneous commutation failure in HVDC about hierarchical connection to AC grid
NASA Astrophysics Data System (ADS)
Li, Ming; Song, Xinli; Huang, Daoshan; Liu, Wenzhuo; Zhao, Shutao; Ye, Xiaohui; Meng, Hang
2017-09-01
The hierarchical connection to AC grid at inverter sides in UHVDC has been take in several projects. This paper introduced the frame of the connection mode in hierarchical access system and compared it with the traditional one at the case of HVDC-Cigre. Then the criterion of commutation failure according to the same valves current was deduced. In order to verify the accuracy of the criterion, this paper used PSD-BPA (Bonneville Power Administration) to simulate the setting voltage drop in the East China power grid and certified the correctness of the formula.
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.
Features of Synchronous Electronically Commutated Motors in Servomotor Operation Modes
NASA Astrophysics Data System (ADS)
Dirba, J.; Lavrinovicha, L.; Dobriyan, R.
2017-04-01
The authors consider the features and operation specifics of the synchronous permanent magnet motors and the synchronous reluctance motors with electronic commutation in servomotor operation modes. Calculation results show that mechanical and control characteristics of studied motors are close to a linear shape. The studied motor control is proposed to implement similar to phase control of induction servomotor; it means that angle θ (angle between vectors of the supply voltage and non-load electromotive force) or angle ɛ (angle between rotor direct axis and armature magnetomotive force axis) is changed. The analysis results show that synchronous electronically commutated motors could be used as servomotors.
The Kaehler Potential of the Non-commutative CP{sup 1} model
Lechtenfeld, Olaf; Maceda, Marco
2010-12-07
We present some results on the moduli space for the charge two-soliton solution of the non-commutative CP{sup 1} model. The associated Kaehler potential and its relation to the commutative case are discussed.
Passive commuting and dietary intake in fourth and fifth grade students.
Madsen, Kristine A; Cotterman, Carolyn; Thompson, Hannah R; Rissman, Yedida; Rosen, Nila J; Ritchie, Lorrene D
2015-03-01
Promoting active commuting by walking or biking to and from school could increase physical activity and reduce obesity among youth. However, exposure to the retail food environment while commuting may lead to greater dietary intake among active commuters. To examine the relationship between commute patterns and dietary intake and quality in elementary students. Fourth and fifth grade students (N=3,316) in 44 California schools reported commute modes to and from school and dietary intake for the same 24-hour period in 2012. Differences between active and passive commuters in total energy intake (kcal), energy from purchased foods, and energy from sweets and snack-type foods were compared, stratified by after-school program (ASP) participation (analysis conducted in 2013). Twenty-three percent of youth actively commuted to school; 27% actively commuted from school. Passive commuters, 87% of whom traveled by car, consumed 78 more kcal from purchased foods (p<0.01) than active commuters in the 24-hour period, though total energy intake did not differ by commute mode overall or by ASP participation. Among the 72% of students who did not attend an ASP, passive commuters consumed 56 more kcal from purchased foods (p<0.01) and 25 more kcal from sweets and snack-type foods (p=0.02) than active commuters. Passive commuters consumed more sweets and snack-type foods and more purchased foods than active commuters. These results, which suggest that parents are providing unhealthy foods for their children during the school commute, reinforce the need for multilevel strategies to promote energy balance in youth. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.
Associations between long commutes and subjective health complaints among railway workers in Norway.
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.
van der Vorm, Lisa N; Hendriks, Jan C M; Laarakkers, Coby M; Klaver, Siem; Armitage, Andrew E; Bamberg, Alison; Geurts-Moespot, Anneke J; Girelli, Domenico; Herkert, Matthias; Itkonen, Outi; Konrad, Robert J; Tomosugi, Naohisa; Westerman, Mark; Bansal, Sukhvinder S; Campostrini, Natascia; Drakesmith, Hal; Fillet, Marianne; Olbina, Gordana; Pasricha, Sant-Rayn; Pitts, Kelly R; Sloan, John H; Tagliaro, Franco; Weykamp, Cas W; Swinkels, Dorine W
2016-07-01
Absolute plasma hepcidin concentrations measured by various procedures differ substantially, complicating interpretation of results and rendering reference intervals method dependent. We investigated the degree of equivalence achievable by harmonization and the identification of a commutable secondary reference material to accomplish this goal. We applied technical procedures to achieve harmonization developed by the Consortium for Harmonization of Clinical Laboratory Results. Eleven plasma hepcidin measurement procedures (5 mass spectrometry based and 6 immunochemical based) quantified native individual plasma samples (n = 32) and native plasma pools (n = 8) to assess analytical performance and current and achievable equivalence. In addition, 8 types of candidate reference materials (3 concentrations each, n = 24) were assessed for their suitability, most notably in terms of commutability, to serve as secondary reference material. Absolute hepcidin values and reproducibility (intrameasurement procedure CVs 2.9%-8.7%) differed substantially between measurement procedures, but all were linear and correlated well. The current equivalence (intermeasurement procedure CV 28.6%) between the methods was mainly attributable to differences in calibration and could thus be improved by harmonization with a common calibrator. Linear regression analysis and standardized residuals showed that a candidate reference material consisting of native lyophilized plasma with cryolyoprotectant was commutable for all measurement procedures. Mathematically simulated harmonization with this calibrator resulted in a maximum achievable equivalence of 7.7%. The secondary reference material identified in this study has the potential to substantially improve equivalence between hepcidin measurement procedures and contributes to the establishment of a traceability chain that will ultimately allow standardization of hepcidin measurement results. © 2016 American Association for Clinical Chemistry.
Experimental Verification of Look-Up Table Based Real-Time Commutation of 6-DOF Planar Actuators
NASA Astrophysics Data System (ADS)
Boeij, Jeroen De; Lomonova, Elena
The control of contactless magnetically levitated planar actuators with stationary coils, moving magnets and 6-DOF is very complicated. In contradiction to normal synchronous AC machines the forces and torques cannot be decoupled using a sinusoidal commutation scheme. Instead, a feedback linearization law has to be applied as commutation scheme that decouples the forces and torques and calculates the required currents to realize the desired forces and torques of the magnetic suspension. This feedback linearization law is based on the coupling matrix that links the current in each coil to the force and torque vector on the actuator. The accurate calculation of this coupling matrix in real-time is critical for controlling the planar actuator. In this paper a look-up table based method is used to apply feedback linearization and the performance of the algorithm is verified with measurements.
49 CFR 37.85 - Purchase or lease of new intercity and commuter rail cars.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 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...
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 and...
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 and...
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 and...
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...
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...
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.…
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…
49 CFR 37.87 - Purchase or lease of used intercity and commuter rail cars.
Code of Federal Regulations, 2010 CFR
2010-10-01
... commuter rail cars from any source. (e) Amtrak and commuter authorities purchasing or leasing used... 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...
40 CFR 52.1161 - Incentives for reduction in single-passenger commuter vehicle use.
Code of Federal Regulations, 2014 CFR
2014-07-01
...-passenger commuter vehicle use. 52.1161 Section 52.1161 Protection of Environment ENVIRONMENTAL PROTECTION...) Massachusetts § 52.1161 Incentives for reduction in single-passenger commuter vehicle use. (a) Definitions: (1... employee and a student. (7) Single-passenger commuter vehicle means a motor-driven vehicle with four or...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-27
...: Commuting is an essential and growing component of daily life for most American workers, making up about 20... American economy. Among the 140 million workers in America, 86.1% commuted in a car, truck, or van in 2009... workers took an average of 25.1 minutes to get to work; more than 3.2 million U.S. workers commute...
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...
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...
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...
Resident and Commuter Students: Is It Only the Living Situation?
ERIC Educational Resources Information Center
Welty, John D.
1976-01-01
The impact of the residence hall and commuter living situations on a freshman's intellectual and personal growth is studied. The study affirms previous findings that residence hall freshmen develop more rapidly, but the results suggest that other college experience factors beyond the living situation are important in facilitating student…
FACTORS EFFECTING EXPOSURES TO VOCS DURING COMMUTING IN CALIFORNIA
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...
Analyses of School Commuting Data for Exposure Modeling Purposes
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...
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.
Integrating Place and Time with Tasks: Supporting the Student Commuter
ERIC Educational Resources Information Center
Lackey, Stephen
2014-01-01
Though the role of traveler information in transportation has been widely recognized in Activity Analysis research, the needs of specific populations receive limited attention. The commuting burden on community college students received comparatively little attention, despite first semester attrition rates and sharp declines in observed parking…
26 CFR 49.4263-1 - Commutation tickets.
Code of Federal Regulations, 2010 CFR
2010-04-01
...) Tickets for single trips of less than 30 miles. Amounts paid for commutation or season tickets or books for single trips of less than 30 miles are exempt from the tax imposed by section 4261, regardless of... exempt from the tax regardless of the distance of a single trip. ...
Resident and Commuter Students: Is It Only the Living Situation?
ERIC Educational Resources Information Center
Welty, John D.
1976-01-01
The impact of the residence hall and commuter living situations on a freshman's intellectual and personal growth is studied. The study affirms previous findings that residence hall freshmen develop more rapidly, but the results suggest that other college experience factors beyond the living situation are important in facilitating student…
Active commuting to elementary school and adiposity: An observational study
USDA-ARS?s Scientific Manuscript database
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 ...
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.
Tape Recorders and the Commuter Student: Bypassing the Red Pen.
ERIC Educational Resources Information Center
Kates, Ronald
1998-01-01
Discusses several ways in which tape-recorded responses by the instructor to student writing can benefit commuter students. Discusses how the audio cassette responses are paired with a series of questions on the writing process and how the author shapes his tape-recorded comments. Notes student responses about the advantages of this approach. (SR)
Integrating Place and Time with Tasks: Supporting the Student Commuter
ERIC Educational Resources Information Center
Lackey, Stephen
2014-01-01
Though the role of traveler information in transportation has been widely recognized in Activity Analysis research, the needs of specific populations receive limited attention. The commuting burden on community college students received comparatively little attention, despite first semester attrition rates and sharp declines in observed parking…
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…
Ethnic Enclave Residence, Employment, and Commuting of Latino Workers
ERIC Educational Resources Information Center
Liu, Cathy Yang
2009-01-01
This paper examines the impact of living in ethnic enclaves in different parts of a metropolitan area on low-skilled Latino immigrants' employment accessibility. It does so by comparing the employment status and commuting times of Latinos living in and out of ethnic neighborhoods in central city, inner-ring suburbs, and outer-ring suburbs in…
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…
Retention Strategies at an Open Enrollment Commuter College.
ERIC Educational Resources Information Center
Gittman, Elizabeth; Plumer, Davenport
The undergraduate population at the New York Institute of Technology (NYIT), an open enrollment four-year commuter college, is highly vulnerable to attrition. Fifty-two percent of the students enrolled between July 1, 1991 and July 1, 1995 either did not graduate after 4 years or did not return to school. In response, the college has developed…
FACTORS EFFECTING EXPOSURES TO VOCS DURING COMMUTING IN CALIFORNIA
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...
Commute Maps: Separating Slowly Mixing Molecular Configurations for Kinetic Modeling.
Noé, Frank; Banisch, Ralf; Clementi, Cecilia
2016-11-08
Identification of the main reaction coordinates and building of kinetic models of macromolecular systems require a way to measure distances between molecular configurations that can distinguish slowly interconverting states. Here we define the commute distance that can be shown to be closely related to the expected commute time needed to go from one configuration to the other, and back. A practical merit of this quantity is that it can be easily approximated from molecular dynamics data sets when an approximation of the Markov operator eigenfunctions is available, which can be achieved by the variational approach to approximate eigenfunctions of Markov operators, also called variational approach of conformation dynamics (VAC) or the time-lagged independent component analysis (TICA). The VAC or TICA components can be scaled such that a so-called commute map is obtained in which Euclidean distance corresponds to the commute distance, and thus kinetic models such as Markov state models can be computed based on Euclidean operations, such as standard clustering. In addition, the distance metric gives rise to a quantity we call total kinetic content, which is an excellent score to rank input feature sets and kinetic model quality.
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…
Analyses of School Commuting Data for Exposure Modeling Purposes
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...
Ethnic Enclave Residence, Employment, and Commuting of Latino Workers
ERIC Educational Resources Information Center
Liu, Cathy Yang
2009-01-01
This paper examines the impact of living in ethnic enclaves in different parts of a metropolitan area on low-skilled Latino immigrants' employment accessibility. It does so by comparing the employment status and commuting times of Latinos living in and out of ethnic neighborhoods in central city, inner-ring suburbs, and outer-ring suburbs in…
Epidemic Process over the Commute Network in a Metropolitan Area
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. PMID:24905831
Epidemic process over the commute network in a metropolitan area.
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.
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
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.
Parental perceptions of barriers to active commuting to school in Spanish children and adolescents.
Huertas-Delgado, Francisco Javier; Herrador-Colmenero, Manuel; Villa-González, Emilio; Aranda-Balboa, María Jesús; Cáceres, María Victoria; Mandic, Sandra; Chillón, Palma
2017-06-01
: Understanding parental barriers is crucial to promote active commuting to school since the parental perceptions influence how young people commute. This study examined parental barriers to active commuting to school among Spanish children and adolescents, and their association with their gender and the usual mode of commuting. Parents of children ( n = 628) and parents of adolescents ( n = 151) from Granada (Spain) completed a paper-based questionnaire about perceived parental barriers to active commuting to school and mode of commuting. Data were analyzed using the Chi-square test. Among Spanish parents, the most common barriers reported by parents of children were traffic volume and dangerous intersections, whereas the most frequent barriers reported by parents of adolescents were distance to school and dangerous intersections. Compared to parents of children, a greater proportion of parents of adolescents reported distance to school and crime and smaller proportion reported traffic volume as barriers to active commuting to school. Among parents of children, crime was a more commonly reported as a barrier by parents of girls. Although some barriers reported by parents of passive commuters were similar for children and adolescents (such as distance to school and absence of a policeman at crosswalks), other barriers were specific to parents of children. The main parental barriers to active commuting in children were traffic volume and dangerous intersections whereas for adolescents were distance and dangerous intersections. Among Spanish parents, parental barriers to active commuting are influenced by children's age, gender and mode of commuting to school.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 1 2012-10-01 2012-10-01 false Remanufacture of intercity and commuter rail cars and purchase or lease of remanufactured intercity and commuter rail cars. 37.89 Section 37.89... commuter rail cars and purchase or lease of remanufactured intercity and commuter rail cars. (a)...
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 1 2013-10-01 2013-10-01 false Remanufacture of intercity and commuter rail cars and purchase or lease of remanufactured intercity and commuter rail cars. 37.89 Section 37.89... commuter rail cars and purchase or lease of remanufactured intercity and commuter rail cars. (a)...
PWM Control of Three-Phase to Three-Phase Matrix Converters for Reducing a Number of Commutations
NASA Astrophysics Data System (ADS)
Takeshita, Takaharu; Andou, Yusuke
This paper presents a control scheme of three-phase to three-phase matrix converters for reducing the number of commutations. The number of commutations during a control period in the proposed control scheme can be reduced to three times from four times in the conventional control scheme. It can be realized by using the output currents in the calculations of the duty factors. As a result, one of the output line voltage waveforms during a control period consists of two voltage levels with same sign of the reference. The switching loss and the output voltage harmonics can be suppressed. The effectiveness of the proposed control algorithm of the matrix converters has been verified by experiments.
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.
Commuting flows and conservation laws for noncommutative Lax hierarchies
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.
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.
How well do cognitive and environmental variables predict active commuting?
Lemieux, Mélanie; Godin, Gaston
2009-01-01
Background In recent years, there has been growing interest in theoretical studies integrating cognitions and environmental variables in the prediction of behaviour related to the obesity epidemic. This is the approach adopted in the present study in reference to the theory of planned behaviour. More precisely, the aim of this study was to determine the contribution of cognitive and environmental variables in the prediction of active commuting to get to and from work or school. Methods A prospective study was carried out with 130 undergraduate and graduate students (93 females; 37 males). Environmental, cognitive and socio-demographic variables were evaluated at baseline by questionnaire. Two weeks later, active commuting (walking/bicycling) to get to and from work or school was self-reported by questionnaire. Hierarchical multiple regression analyses were performed to predict intention and behaviour. Results The model predicting behaviour based on cognitive variables explained more variance than the model based on environmental variables (37.4% versus 26.8%; Z = 3.86, p < 0.001). Combining cognitive and environmental variables with socio-demographic variables to predict behaviour yielded a final model explaining 41.1% (p < 0.001) of the variance. The significant determinants were intention, habit and age. Concerning intention, the same procedure yielded a final model explaining 78.2% (p < 0.001) of the variance, with perceived behavioural control, attitude and habit being the significant determinants. Conclusion The results showed that cognitive variables play a more important role than environmental variables in predicting and explaining active commuting. When environmental variables were significant, they were mediated by cognitive variables. Therefore, individual cognitions should remain one of the main focuses of interventions promoting active commuting among undergraduate and graduate students. PMID:19267911
Markov property of Gaussian states of canonical commutation relation algebras
NASA Astrophysics Data System (ADS)
Petz, Dénes; Pitrik, József
2009-11-01
The Markov property of Gaussian states of canonical commutation relation algebras is studied. The detailed description is given by the representing block matrix. The proof is short and allows infinite dimension. The relation to classical Gaussian Markov triplets is also described. The minimizer of relative entropy with respect to a Gaussian Markov state has the Markov property. The appendix contains formulas for the relative entropy.
Commutator-based linearization of N = 1 nonlinear supersymmetry
NASA Astrophysics Data System (ADS)
Tsuda, Motomu
2016-11-01
We consider the linearization of N = 1 nonlinear supersymmetry (NLSUSY) based on a commutator algebra in Volkov-Akulov (VA) NLSUSY theory. We show explicitly that U(1) gauge and scalar supermultiplets in addition to a vector supermultiplet with general auxiliary fields in linear SUSY theories are obtained from a same set of bosonic and fermionic functionals (composites) which are expressed as simple products of the powers of a Nambu-Goldstone fermion and a fundamental determinant in the NLSUSY theory.
Yang, Lin; Panter, Jenna; Griffin, Simon J.; Ogilvie, David
2012-01-01
Objective To quantify the association between time spent in active commuting and in moderate to vigorous physical activity (MVPA) in a sample of working adults living in both urban and rural locations. Methods In 2009, participants in the Commuting and Health in Cambridge study were sent questionnaires enquiring about sociodemographic characteristics and weekly time spent in active commuting. They were also invited to wear an accelerometer for seven days. Accelerometer data were used to compute the time spent in MVPA. Multiple regression models were used to examine the association between time spent in active commuting and MVPA. Results 475 participants (70% female) provided valid data. On average, participants recorded 55 (SD: 23.02) minutes of MVPA per day. For women, reporting 150 or more minutes of active commuting per week was associated with an estimated 8.50 (95% CI: 1.75 to 51.26, p = 0.01) additional minutes of daily MVPA compared to those who reported no time in active commuting. No overall associations were found in men. Conclusions Promoting active commuting might be an important way of increasing levels of physical activity, particularly in women. Further research should assess whether increases in time spent in active commuting are associated with increases in physical activity. PMID:22964003
Exploring universal patterns in human home-work commuting from mobile phone data.
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.
Magnetic-free non-reciprocity based on staggered commutation
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
[Relationships between settlement morphology transition and residents commuting energy consumption].
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.
Magnetic-free non-reciprocity based on staggered commutation.
Reiskarimian, Negar; Krishnaswamy, Harish
2016-04-15
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.
Modelling the relation between income and commuting distance.
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.
Djurhuus, Sune; Hansen, Henning Sten; Aadahl, Mette; Glümer, Charlotte
2014-01-01
Background: Active commuters have lower risk of chronic disease. Understanding which of the, to some extent, modifiable characteristics of public transportation that facilitate its use is thus important in a public health perspective. The aim of the study was to examine the association between individual public transportation accessibility and self-reported active commuting, and whether the associations varied with commute distance, age, and gender. Methods: Twenty-eight thousand nine hundred twenty-eight commuters in The Capital Region of Denmark reported self-reported time spent either walking or cycling to work or study each day and the distance to work or study. Data were obtained from the Danish National Health Survey collected in February to April 2010. Individual accessibility by public transportation was calculated using a multi-modal network in a GIS. Multilevel logistic regression was used to analyze the association between accessibility, expressed as access area, and being an active commuter. Results: Public transport accessibility area based on all stops within walking and cycling distance was positively associated with being an active commuter. Distance to work, age, and gender modified the associations. Residing within 10 km commute distance and in areas of high accessibility was associated with being an active commuter and meeting the recommendations of physical activity. For the respondents above 29 years, individual public transportation accessibility was positively associated with being an active commuter. Women having high accessibility had significantly higher odds of being an active commuter compared to having a low accessibility. For men, the associations were insignificant. Conclusion: This study extends the knowledge about the driving forces of using public transportation for commuting by examining the individual public transportation accessibility. Findings suggest that transportation accessibility supports active commuting and planning
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.
Nelson, Bryant C; Pfeiffer, Christine M; Zhang, Ming; Duewer, David L; Sharpless, Katherine E; Lippa, Katrice A
2008-09-01
The National Institute of Standards and Technology (NIST) has recently developed Standard Reference Material (SRM) 1955 Homocysteine and Folate in Frozen Human Serum with certified values for total homocysteine (tHcy) and 5-methyl-tetrahydrofolic acid. NIST has performed an international, interlaboratory assessment of SRM 1955 commutability; results are reported for tHcy only. Total Hcy was measured in 20 patient sera and in 3 levels of SRM 1955 using 14 immunoassays and/or enzymatic assays. Liquid chromatography/tandem mass spectrometry was utilized as the reference assay. An "errors-in-variables" statistical model was utilized to assess the commutability of SRM 1955. Normalized residuals ranged from -2.65 to 2.19 for SRM 1955. The median interlaboratory/interassay imprecision (CV) was approximately 4% for patient specimens and ranged from approximately 3% to approximately 7% for SRM 1955. The median intra-assay imprecision ranged from approximately 1% to approximately 13%. Orthogonal residuals, as a descriptor of assay accuracy, ranged from 0.29 to 7.71 and from 0.20 to 2.22 for patient specimens and SRM 1955 samples, respectively. The current study suggests that SRM 1955 is commutable with the investigated tHcy assays; however, a broader specimen set needs to be evaluated to completely substantiate this conclusion.
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".
Page, Nadine C.; Nilsson, Viktor O.
2017-01-01
Objective: This paper describes a behavior change intervention that encourages active commuting using electrically assisted bikes (e-bikes) for health promotion in the workplace. This paper presents the preliminary findings of the intervention’s impact on improving employee well-being and organizational behavior, as an indicator of potential business success. Method: Employees of a UK-based organization participated in a workplace travel behavior change intervention and used e-bikes as an active commuting mode; this was a change to their usual passive commuting behavior. The purpose of the intervention was to develop employee well-being and organizational behavior for improved business success. We explored the personal benefits and organizational co-benefits of active commuting and compared these to a travel-as-usual group of employees who did not change their behavior and continued taking non-active commutes. Results: Employees who changed their behavior to active commuting reported more positive affect, better physical health and more productive organizational behavior outcomes compared with passive commuters. In addition, there was an interactive effect of commuting mode and commuting distance: a more frequent active commute was positively associated with more productive organizational behavior and stronger overall positive employee well-being whereas a longer passive commute was associated with poorer well-being, although there was no impact on organizational behavior. Conclusion: This research provides emerging evidence of the value of an innovative workplace health promotion initiative focused on active commuting in protecting and improving employee well-being and organizational behavior for stronger business performance. It considers the significant opportunities for organizations pursuing improved workforce well-being, both in terms of employee health, and for improved organizational behavior and business success. PMID:28119640
Trade-offs between commuting time and health-related activities.
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.
Page, Nadine C; Nilsson, Viktor O
2016-01-01
Objective: This paper describes a behavior change intervention that encourages active commuting using electrically assisted bikes (e-bikes) for health promotion in the workplace. This paper presents the preliminary findings of the intervention's impact on improving employee well-being and organizational behavior, as an indicator of potential business success. Method: Employees of a UK-based organization participated in a workplace travel behavior change intervention and used e-bikes as an active commuting mode; this was a change to their usual passive commuting behavior. The purpose of the intervention was to develop employee well-being and organizational behavior for improved business success. We explored the personal benefits and organizational co-benefits of active commuting and compared these to a travel-as-usual group of employees who did not change their behavior and continued taking non-active commutes. Results: Employees who changed their behavior to active commuting reported more positive affect, better physical health and more productive organizational behavior outcomes compared with passive commuters. In addition, there was an interactive effect of commuting mode and commuting distance: a more frequent active commute was positively associated with more productive organizational behavior and stronger overall positive employee well-being whereas a longer passive commute was associated with poorer well-being, although there was no impact on organizational behavior. Conclusion: This research provides emerging evidence of the value of an innovative workplace health promotion initiative focused on active commuting in protecting and improving employee well-being and organizational behavior for stronger business performance. It considers the significant opportunities for organizations pursuing improved workforce well-being, both in terms of employee health, and for improved organizational behavior and business success.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-27
..., Acrobatic, and Commuter Category Small Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... with certification, maintenance, modifications, and pilot training. Also included in the report is...
NASA Astrophysics Data System (ADS)
Bakar, Fadhilah Abu; Ali, Nor Muhainiah Mohd; Rhani, Norarida Abd
2017-08-01
A metabelian group is a group G that have at least an abelian normal subgroup N such that the quotient group G/N is also abelian. The concept of commutativity degree plays as important role in determining the abelianness of the group. This concept has been extended to the relative commutativity degree of a subgroup H of a group G which defined as the probability that an element of H commutes with an element of G. In this paper, the relative commutativity degree for noncyclic subgroups of nonabelian metabelian groups of order at most 14 are determined.
14 CFR 135.398 - Commuter category airplanes performance operating limitations.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 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...
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...
14 CFR 135.398 - Commuter category airplanes performance operating limitations.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 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...
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...
14 CFR 135.398 - Commuter category airplanes performance operating limitations.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 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...
Branes as Stable Holomorphic Line Bundles On the Non-Commutative Torus
NASA Astrophysics Data System (ADS)
Grange, Pascal
2004-10-01
It was suggested by A. Kapustin that turning on a B-field, and allowing some discrepancy between the left and and right-moving complex structures, must induce an identification of B-branes with holomorphic line bundles on a non-commutative complex torus. The stability condition for the branes is written as a topological identity of non-commutative gauge theory. This identifies stable B-branes with previously proposed non-commutative instanton equations. Consistency of the non-commutative description with complex geometry is examined, using the non-linearities of the Seiberg-Witten map.
Potential Health Impact of Switching From Car to Public Transportation When Commuting to Work
Mirer, Franklin E.; Amstislavski, Tashia M.; Eisl, Holger M.; Werbe-Fuentes, Jordan; Gorczynski, John; Goranson, Chris; Wolff, Mary S.; Markowitz, Steven B.
2010-01-01
We assessed humidity-corrected particulate matter (PM2.5) 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 PM2.5 differed little between car and public transportation commutes (1.41 μg/M3·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. PMID:20966368
Potential health impact of switching from car to public transportation when commuting to work.
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.
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.
Analysis, design, and control of a novel optically commutated adjustable-speed motor
NASA Astrophysics Data System (ADS)
Newman, Wyatt S.; Risch, Ivan; Zhang, Yuandao; Garverick, Steven; Inerfield, Michael
1998-12-01
This paper describes the analysis, design and control of a novel, single-phase motor with a unique behavior resulting from the use of rotating power electronics mounted to the motor armature. Coils on the armature are selectively shorted by power MOSFET's which rotate with the armature, and torque is produced by interaction between currents induced in the shorted coils and the magnetic field produced by a stationary field coil. Control is limited to the timing of which armature coils are to be shorted as a function of armature speed and angle, it is possible to modulate torque production and obtain torque or speed control using only single-phase ac power and without the use of brushes or permanent magnets. An electro-mechanical model for this type of motor is presented and validated with respect to experimentation. The results show promise for achieving low- cost, adjustable-speed drives using this novel method of rotating electronics, optical communications, and computed commutation.
Process of commutation of a vacuum electric-discharge gap by laser plasma
Davydov, S. G. Dolgov, A. N.; Kozlovskaya, T. I.; Revazov, V. O.; Seleznev, V. P.; Yakubov, R. Kh.
2016-01-15
The temporal parameters of a process of vacuum gap commutation under exposure to a nanosecond pulse of laser radiation incident on the cathode has been studied depending on the radiation energy. Based on the experiment data, it is suggested that a glow discharge is initially ignited in electrode erosion products under exposure to the laser pulse, which due to development of the ionization-overheating instability undergoes the contraction of current channel and transits to an arc discharge. With the radiation energy exceeding a threshold value, the radiation (incident on the cathode) accelerates directly the instability development and the glow discharge transition to the arc discharge due to the radiation absorption in the discharge plasma.
Field Theoretic Investigations in Current Algebra
NASA Astrophysics Data System (ADS)
Jackiw, Roman
The following sections are included: * Introduction * Canonical and Space-Time Constraints in Current Algebra * Canonical Theory of Currents * Space-Time Constraints on Commutators * Space-Time Constraints on Green's Functions * Space-Time Constraints on Ward Identities * Schwinger Terms * Discussion * The Bjorken-Johnson-Low Limit * The π 0 → 2γ Problem * Preliminaries * Sutherland-Veltman Theorem * Model Calculation * Anomalous Ward Identity * Anomalous Commutators * Anomalous Divergence of Axial Current * Discussion * Electroproduction Sum Rules * Preliminaries * Derivation of Sum Rules, Naive Method * Derivation of Sum Rules, Dispersive Method * Model Calculation * Anomalous Commutators * Discussion * Discussion of Anomalies in Current Algebra * Miscellaneous Anomalies * Non-Perturbative Arguments for Anomalies * Models without Anomalies * Discussion * Approximate Scale Symmetry * Introduction * Canonical Theory of Scale and Conformal Transformations * Ward Identities and Trace Identities * False Theorems * True Theorems * EXERCISES * SOLUTIONS
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.
Fock representations of Q-deformed commutation relations
NASA Astrophysics Data System (ADS)
BoŻejko, Marek; Lytvynov, Eugene; Wysoczański, Janusz
2017-07-01
We consider Fock representations of the Q-deformed commutation relations ∂s∂t†=Q (s ,t ) ∂t†∂s+δ (s ,t ) for s ,t ∈T . Here T :=Rd (or more generally T is a locally compact Polish space), the function Q :T2→C satisfies |Q (s ,t ) |≤1 and Q (s ,t ) =Q (t ,s ) ¯ , and ∫T2h (s ) g (t ) δ (s ,t ) σ (d s ) σ (d t ) :=∫Th (t ) g (t ) σ (d t ) , σ being a fixed reference measure on T. In the case, where |Q (s ,t ) |≡1 , the Q-deformed commutation relations describe a generalized statistics studied by Liguori and Mintchev. These generalized statistics contain anyon statistics as a special case (with T =R2 and a special choice of the function Q). The related Q-deformed Fock space F (H ) over H :=L2(T →C ,σ ) is constructed. An explicit form of the orthogonal projection of H⊗n onto the n-particle space Fn(H ) is derived. A scalar product in Fn(H ) is given by an operator Pn≥0 in H⊗n which is strictly positive on Fn(H ) . We realize the smeared operators ∂t† and ∂t as creation and annihilation operators in F (H ) , respectively. Additional Q-commutation relations are obtained between the creation operators and between the annihilation operators. They are of the form ∂s†∂t†=Q (t ,s ) ∂t†∂s†, ∂s∂t=Q (t ,s ) ∂t∂s, valid for those s ,t ∈T for which |Q(s, t)| = 1.
Exposure to hydrocarbon concentrations while commuting or exercising in Dublin.
O'Donoghue, R T; Gill, L W; McKevitt, R J; Broderick, B
2007-01-01
In Ireland, several studies have monitored the air pollution due to traffic in both urban and rural environments. However, few studies have attempted to quantify the relative exposure to traffic derived HC pollutants between different modes of commuter transport. In this study, the difference in pollution exposure between bus and cycling commuters on a route in Dublin was compared by sampling for five vehicle related hydrocarbons: benzene, 1,3-butadiene, acetylene, ethane and ethylene. Samples were collected during both morning and afternoon rush hour periods using a fixed speed pump to gain representative concentrations across the whole journey. Journey times were also measured, as were typical breathing rates in order to calculate the overall dose of pollutant inhaled on the journey. Results clearly picked up significantly higher pollutant concentrations in the bus compared to cycling and also revealed elevated concentrations on the congested side of the road compared to the side moving against the traffic. However, when respiration rates and travel times were taken into account to reveal the mass of pollutants inhaled over the course of a journey, the pattern was reversed, showing slightly enhanced levels of hydrocarbons for the cyclist compared to the bus passenger. In addition, the concentrations of these compounds (excluding ethane), were ascertained at playing pitches in the vicinity of a heavily trafficked suburban motorway and in Dublin city centre. Although the concentrations were relatively low at all sites, when breathing rates were taken into consideration, the average inhaled weights of pollutants were, on occasion, higher than those average values observed for both bus and bicycle commuters.
Le contrôle de commutations dans une cellule bidirectionnelle bicommandable
NASA Astrophysics Data System (ADS)
Guillaud, X.; Deleu, A.; Degobert, P.; Hautier, J. P.
1996-01-01
A Power electronics static converter modulate the energy flowing between two different source types. This induce constraints in converter topology which need to be taken into account to drive the switches specially during the changeover between two switches belonging to the same cell. If the control logic is well known when using current or voltage bidirectionnal switches, we propose a method which fits to bidrivable, current and voltage bidirectionnal switches. Petri net are usefull tools to describe the switches themselves. Aplied to the cell description they permit us to generate a component logic drive in respect with energy constraints. Un convertisseur statique réalise une fonction de modulation de l'énergie transitant entre deux sources de nature différente. La nécessaire continuité énergétique induit des contraintes dans la topologie du convertisseur qui se répercutent sur la commande des composants qui le constituent, notamment lors de la phase de commutation entre deux interrupteurs d'une même cellule. Si les principes de commande sont bien connus pour les interrupteurs bidirectionnels en courant ou en tension, nous proposons dans cet article une méthode s'appliquant aux interrupteurs bicommandables et bidirectionnels à la fois en courant et en tension. Les réseaux de Petri constituent d'abord un outil de description précis des interrupteurs. Appliqués ensuite à la description du fonctionnement d'une cellule de commutation, ils deviennent alors un outil de synthèse conduisant à l'élaboration d'une logique de commande respectant les contraintes énergétiques dans tous les cas de figure.
Analysis of School Commuting Data for Exposure Modeling Purposes
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
Remote Sensing with Commutable Monolithic Laser and Detector.
Szedlak, Rolf; Harrer, Andreas; Holzbauer, Martin; Schwarz, Benedikt; Waclawek, Johannes Paul; MacFarland, Donald; Zederbauer, Tobias; Detz, Hermann; Andrews, Aaron Maxwell; Schrenk, Werner; Lendl, Bernhard; Strasser, Gottfried
2016-10-19
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.
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.
Commutativity-Based Concurrency Control for Abstract Data Types
1988-08-01
34...oS.(SI($)). 13 and is -± otherwise. Thus, P(Q(s)) is s if ies, and is -L otherwise, while Q(P(s)) = sv(i). Hence Pand Qdo not commute backward. In...References [1] Allchin, J. E. An architecture for reliable decentralized systems. PhD thesis , Georgia Institute of Technology, September, 1983...International Conference on Database Theory. [181 Moss, J.E.B. Nested transactions: an approach to reliable distributed compulng. PhD thesis , Massachusetts
Remote Sensing with Commutable Monolithic Laser and Detector
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
On commutativity of weighted Hankel operators and their spectra
NASA Astrophysics Data System (ADS)
Datt, Gopal; Porwal, Deepak Kumar
2015-08-01
In this paper, we describe the conditions on which the nonzero weighted Hankel operators Hφ β and Hψ β on H2(β) induced by ϕ ∈ L∞(β) and ψ ∈ L∞(β) respectively commute, where β = {βn}n∈ℤ is a sequence of positive numbers with β0 = 1. Spectrum of the weighted Hankel operator Hφ β , when ϕ(z) = az-1 + bz-2, is computed and it is also shown that the Weyl's theorem holds for the compact weighted Hankel operators.
A geometrical characterization of commutative positive operator valued measures
Beneduci, Roberto
2006-06-15
We show that a POV measure F on the Borel {sigma}-algebra of the reals B(R) is commutative if and only if there exists a PV measure E on B(R) and, for every {lambda} in the spectrum of E, a probability measure {gamma}{sub ({center_dot})}({lambda}) on B(R) such that the effect F({delta}) coincides with {gamma}{sub {delta}}(A), where A is the self-adjoint operator associated to E. The relevance of this result to the theory of the sharp reconstruction is analyzed.
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.
Guell, C; Panter, J; Jones, N R; Ogilvie, D
2012-07-01
Fostering physical activity is an established public health priority for the primary prevention of a variety of chronic diseases. One promising population approach is to seek to embed physical activity in everyday lives by promoting walking and cycling to and from work ('active commuting') as an alternative to driving. Predominantly quantitative epidemiological studies have investigated travel behaviours, their determinants and how they may be changed towards more active choices. This study aimed to depart from narrow behavioural approaches to travel and investigate the social context of commuting with qualitative social research methods. Within a social practice theory framework, we explored how people describe their commuting experiences and make commuting decisions, and how travel behaviour is embedded in and shaped by commuters' complex social worlds. Forty-nine semi-structured interviews and eighteen photo-elicitation interviews with accompanying field notes were conducted with a subset of the Commuting and Health in Cambridge study cohort, based in the UK. The findings are discussed in terms of three particularly pertinent facets of the commuting experience. Firstly, choice and decisions are shaped by the constantly changing and fluid nature of commuters' social worlds. Secondly, participants express ambiguities in relation to their reasoning, ambitions and identities as commuters. Finally, commuting needs to be understood as an embodied and emotional practice. With this in mind, we suggest that everyday decision-making in commuting requires the tactical negotiation of these complexities. This study can help to explain the limitations of more quantitative and static models and frameworks in predicting travel behaviour and identify future research directions.
Factors associated with active commuting among parents-to-be in Karlskrona, Sweden.
Thern, Emelie; Forss, Katarina Sjögren; Jogréus, Claes E; Stjernberg, Louise
2015-02-01
The purpose of the present study is to examine the prevalence of active commuting and factors associated with participation in active commuting in the municipality of Karlskrona, Sweden. Active commuting is defined here as walking or cycling to and from school/work for at least 15 minutes one-way. A cross-sectional study was carried out, which included baseline data from parents-to-be. Pregnant females and their partners were invited to participate in the study when they contacted either of the municipality's two antenatal clinics. Data collection ran from March 2008 to February 2009. When completing the questionnaire, the participants were asked to reflect on their situation one month before the female became pregnant. The final sample consisted of 432 participants (response rate 51.9% for females and 85.0% for males). The main mode of commuting was motor vehicle (63.0%), with active commuters forming a minority (8.3%). The main facilitating factor for active commuting was living in an urban as opposed to a rural area. Regular participation in outdoor recreational physical activity was significantly positively associated with active commuting. Being Swedish and being surrounded by a green space environment were significantly negatively associated with active commuting. This study found that the number of people who are active commuters is modest and other modes of transportation are preferred. Several facilitating and impeding factors associated with active commuting were also found, indicating the importance of applying a broad health-promoting approach to encouraging active commuting. © 2014 the Nordic Societies of Public Health.
Mäki-Opas, Tomi E; Borodulin, Katja; Valkeinen, Heli; Stenholm, Sari; Kunst, Anton E; Abel, Thomas; Härkänen, Tommi; Kopperoinen, Leena; Itkonen, Pekka; Prättälä, Ritva; Karvonen, Sakari; Koskinen, Seppo
2016-08-11
The current political agenda aims to promote active environments and physical activity while commuting to work, but research on it has provided mixed results. This study examines whether the proximity of green space and people's residence in different travel-related urban zones contributes to commuting physical activity. Population-based cross-sectional health examination survey, Health 2011 study, and geographical information system (GIS) data were utilized. The GIS data on green space and travel-related urban zones were linked to the individuals of the Health 2011 study, based on their home geocoordinates. Commuting physical activity was self-reported. Logistic regression models were applied, and age, gender, education, leisure-time and occupational physical activity were adjusted. Analyses were limited to those of working age, living in the core-urban areas of Finland and having completed information on commuting physical activity (n = 2 098). Home location in a pedestrian zone of a main centre (odds ratio = 1.63; 95 % confidence interval = 1.06-2.51) or a pedestrian zone of a sub-centre (2.03; 1.09-3.80) and higher proportion of cycling and pedestrian networks (3.28; 1.71-6.31) contributed to higher levels of commuting physical activity. The contribution remained after adjusting for all the environmental attributes and individuals. Based on interaction analyses, women living in a public transport zone were almost two times more likely to be physically active while commuting compared to men. A high proportion of recreational green space contributed negatively to the levels of commuting physical activity (0.73; 0.57-0.94) after adjusting for several background factors. Based on interaction analyses, individuals aged from 44 to 54 years and living in sub-centres, men living in pedestrian zones of sub-centres, and those individuals who are physically inactive during leisure-time were less likely to be physically active while commuting. Good pedestrian
Numerical simulation of nonlinear dynamical systems driven by commutative noise
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.
Breakfast Skipping, Extreme Commutes, and the Sex Composition at Birth.
Mazumder, Bhashkar; Seeskin, Zachary
2015-01-01
A growing body of literature has shown that environmental exposures in the period around conception can affect the sex ratio at birth through selective attrition that favors the survival of female conceptuses. Glucose availability is considered a key indicator of the fetal environment, and its absence as a result of meal skipping may inhibit male survival. We hypothesize that breakfast skipping during pregnancy may lead to a reduction in the fraction of male births. Using time use data from the United States we show that women with commute times of 90 minutes or longer are 20 percentage points more likely to skip breakfast. Using U.S. census data we show that women with commute times of 90 minutes or longer are 1.2 percentage points less likely to have a male child under the age of 2. Under some assumptions, this implies that routinely skipping breakfast around the time of conception leads to a 6 percentage point reduction in the probability of a male child. Skipping breakfast during pregnancy may therefore constitute a poor environment for fetal health more generally.
Examining the Link Between Public Transit Use and Active Commuting
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
Self-testing of binary observables based on commutation
NASA Astrophysics Data System (ADS)
Kaniewski, Jedrzej
2017-06-01
We consider the problem of certifying binary observables based on a Bell inequality violation alone, a task known as self-testing of measurements. We introduce a family of commutation-based measures, which encode all the distinct arrangements of two projective observables on a qubit. These quantities by construction take into account the usual limitations of self-testing and since they are "weighted" by the (reduced) state, they automatically deal with rank-deficient reduced density matrices. We show that these measures can be estimated from the observed Bell violation in several scenarios and the proofs rely only on standard linear algebra. The trade-offs turn out to be tight, and in particular, they give nontrivial statements for arbitrarily small violations. On the other extreme, observing the maximal violation allows us to deduce precisely the form of the observables, which immediately leads to a complete rigidity statement. In particular, we show that for all n ≥3 the n -partite Mermin-Ardehali-Belinskii-Klyshko inequality self-tests the n -partite Greenberger-Horne-Zeilinger state and maximally incompatible qubit measurements on every party. Our results imply that any pair of projective observables on a qubit can be certified in a truly robust manner. Finally, we show that commutation-based measures give a convenient way of expressing relations among more than two observables.
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.
Assessment of noise exposure during commuting in the Madrid subway.
Tabacchi, M; Pavón, I; Ausejo, M; Asensio, C; Recuero, M
2011-09-01
Because noise-induced hearing impairment is the result not only of occupational noise exposure but also of total daily noise exposure, it is important to take the non-occupational exposure of individuals (during commuting to and from their jobs, at home, and during recreational activities) into account. Mass transit is one of the main contributors to non-occupational noise exposure. We developed a new methodology to estimate a representative commuting noise exposure. The methodology was put into practice for the Madrid subway because of all Spanish subway systems it covers the highest percentage of worker journeys (22.6%). The results of the application highlight that, for Madrid subway passengers, noise exposure level normalized to a nominal 8 hr (L(Ex,8h-cj) ) depends strongly on the type of train, the presence of squealing noise, and the public address audio system, ranging from 68.6 dBA to 72.8 dBA. These values play an important role in a more complete evaluation of a relationship between noise dose and worker health response.
Commuting mode and pulmonary function in Shanghai, China
Gaffney, Adam W.; Hang, Jing-qing; Lee, Mi-Sun; Su, Li; Zhang, Fengying; Christiani, David C.
2016-01-01
Introduction 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. Material and methods The Shanghai Putuo Study is a cross-sectional population-based study. Our primary outcomes were FEV1 and FVC percent predicted, and the secondary outcome was spirometric airflow obstruction. We tested the association between mode of transportation and these outcomes after adjusting for confounders. Results The study population consisted of 20,102 subjects. After adjusting for confounders, the FEV1 percent predicted was 2.15 lower (95% CI −2.88, −1.42) among walkers, 1.32 lower (95% CI −2.05, −0.59) among those taking buses without air-conditioning, 1.33 lower (95% CI −2.05, −0.61) among those taking buses with air-conditioning, and 2.83 lower (95% CI −5.56, −0.10) among subway-riders, as compared to cyclists (the reference group). The effects of mode on FVC percent predicted were in the same direction. Private car use had a significant protective effect on FVC percent predicted and the risk of airflow obstruction (defined by GOLD but not by LLN criteria). Conclusions Mode of transportation is associated with differences in lung function, which may reflect pollution levels in different transportation microenvironments. PMID:26541519
40 CFR 52.1161 - Incentives for reduction in single-passenger commuter vehicle use.
Code of Federal Regulations, 2011 CFR
2011-07-01
...-passenger commuter vehicle use. 52.1161 Section 52.1161 Protection of Environment ENVIRONMENTAL PROTECTION...) Massachusetts § 52.1161 Incentives for reduction in single-passenger commuter vehicle use. (a) Definitions: (1... at an educational facility offering secondary level or higher training including vocational...
40 CFR 52.1161 - Incentives for reduction in single-passenger commuter vehicle use.
Code of Federal Regulations, 2013 CFR
2013-07-01
...-passenger commuter vehicle use. 52.1161 Section 52.1161 Protection of Environment ENVIRONMENTAL PROTECTION...) Massachusetts § 52.1161 Incentives for reduction in single-passenger commuter vehicle use. (a) Definitions: (1... at an educational facility offering secondary level or higher training including vocational...
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...
The Student as Commuter: Developing a Comprehensive Institutional Response. ERIC Digest.
ERIC Educational Resources Information Center
Jacoby, Barbara
A preview is given of ASHE-ERIC report no. 7 which focuses on commuting students at colleges and universities and how institutions of higher education can begin to respond to these students' special circumstances that are greatly affecting their educational experience. The diversity of commuter students and their educational goals requires the use…
Commuting, leisure-time physical activity, and cardiovascular risk factors in China.
Hu, Gang; Pekkarinen, Heikki; Hänninen, Osmo; Yu, Zhijie; Guo, Zeyu; Tian, Huiguang
2002-02-01
The relationship between both commuting and leisure-time physical activity and selected cardiovascular risk factors was analyzed. A cross-sectional survey was carried out in 1996 in urban Tianjin, China. A total of 2002 male and 1974 female subjects aged 15-69 yr completed the survey. Commuting, leisure-time physical activity, body mass index, blood pressure, and cigarette smoking were determined. Doing more than 60 min of commuting physical activity or combined commuting and leisure-time physical activity was related to the highest mean blood pressure and the highest prevalence of hypertension among both genders compared with going to and from work by bus; 31-60 min commuting only or commuting plus leisure-time physical activity was associated with the lowest mean blood pressure in women and the lowest prevalence of hypertension in both genders. Daily time on commuting or leisure-time physical activity was inversely related to mean body mass index and prevalence of overweight among men and prevalence of smoking among both genders. The present study suggests that commuting and leisure-time physical activity were favorably associated with cardiovascular risk factors in this Chinese population, except that more than 60 min of physical activity was associated with high blood pressure.
78 FR 75483 - Federal Travel Regulation (FTR); Relocation Allowances; Commuted Rate
Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-12
... cost scenario. This final rule will meet the requirements set forth in the U.S. Code for Relocation... GSA OGP is issuing a new commuted rate chart to meet the requirements of this law. The U.S. Department... treated by Federal agencies as the commuted rate; that is, when a Federal employee moved his/her own...
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?…
49 CFR 37.51 - Key stations in commuter rail systems.
Code of Federal Regulations, 2013 CFR
2013-10-01
... identify key stations, using the planning and public participation process set forth in paragraph (d) of... with major parking facilities, bus terminals, intercity or commuter rail stations, passenger vessel... commuter authority and responsible person(s) also shall hold at least one public hearing on the plan and...
Active commuting to school and association with physical activity and adiposity among US youth
USDA-ARS?s Scientific Manuscript database
Walking or bicycling to school, i.e. active commuting, has shown promise for improving physical activity and preventing obesity in youth. Our objectives were to examine, among US youth, whether active commuting was inversely associated with adiposity and positively associated with moderate-to vigoro...
Almost commuting matrices, localized Wannier functions, and the quantum Hall effect
NASA Astrophysics Data System (ADS)
Hastings, Matthew B.; Loring, Terry A.
2010-01-01
For models of noninteracting fermions moving within sites arranged on a surface in three-dimensional space, there can be obstructions to finding localized Wannier functions. We show that such obstructions are K-theoretic obstructions to approximating almost commuting, complex-valued matrices by commuting matrices, and we demonstrate numerically the presence of this obstruction for a lattice model of the quantum Hall effect in a spherical geometry. The numerical calculation of the obstruction is straightforward and does not require translational invariance or introduce a flux torus. We further show that there is a Z2 index obstruction to approximating almost commuting self-dual matrices by exactly commuting self-dual matrices and present additional conjectures regarding the approximation of almost commuting real and self-dual matrices by exactly commuting real and self-dual matrices. The motivation for considering this problem is the case of physical systems with additional antiunitary symmetries such as time-reversal or particle-hole conjugation. Finally, in the case of the sphere—mathematically speaking, three almost commuting Hermitians whose sum of square is near the identity—we give the first quantitative result, showing that this index is the only obstruction to finding commuting approximations. We review the known nonquantitative results for the torus.
49 CFR 37.51 - Key stations in commuter rail systems.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 1 2014-10-01 2014-10-01 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...
49 CFR 37.51 - Key stations in commuter rail systems.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 1 2012-10-01 2012-10-01 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...
49 CFR 37.51 - Key stations in commuter rail systems.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 1 2011-10-01 2011-10-01 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...
A Comparison of Black and White University Student Commuters. Research Report #2-75.
ERIC Educational Resources Information Center
Sedlacek, William E.; And Others
Mail questionnaires sent to 200 commuters (100 white and 100 black) indicated a number of differences and similarities between the two groups, using chi square and t at the .05 level. The black commuter, as compared to the white, tended to be an older married female traveling further and spending more time and money to get to campus, and receiving…
Active Commuting to School and Association With Physical Activity and Adiposity Among US Youth
Mendoza, Jason A.; Watson, Kathy; Nguyen, Nga; Cerin, Ester; Baranowski, Tom; Nicklas, Theresa A.
2011-01-01
Background Walking or bicycling to school (ie, active commuting) has shown promise for improving physical activity and preventing obesity in youth. Our objectives were to examine, among US youth, whether active commuting was inversely associated with adiposity and positively associated with moderate-to-vigorous physical activity (MVPA). We also examined whether MVPA mediated the relationships between active commuting and adiposity. Methods Using data of participants aged 12 to 19 years from the US National Health and Nutrition Examination Survey 2003 to 2004 (n = 789 unweighted), we constructed multiple linear regression models that controlled for dietary energy intake and sociodemographics. The main exposure variable was active commuting. The outcomes were BMI z-score, waist circumference, skinfolds and objectively measured MVPA. The product-of-coefficients method was used to test for mediation. Results Active commuting was inversely associated with BMI z-score (β = −0.07, P = .046) and skinfolds (β = −0.06, P = .029), and positively associated with overall daily (β = 0.12, P = .024) and before- and after-school (β = 0.20, P < .001) MVPA. Greater before- and after-school MVPA explained part of the relationship between active commuting and waist circumference (Sobel z = −1.98, P = .048). Conclusions Active commuting was associated with greater MVPA and lower measures of adiposity among US youth. Before- and after-school MVPA mediated the relationships between active commuting and waist circumference. PMID:21597121
ERIC Educational Resources Information Center
Shumway, Richard J.
The role of negative instances in the acquisition of the mathematical concepts of commutativity and associativity of a binary operation was examined. Two levels of instruction (positive instances, and positive and negative instances) for commutativity and for associativity were crossed to form a 2 x 2 factorial design with 16 ninth grade subjects…
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
... PROPERTY 7-TRANSPORTATION AND TEMPORARY STORAGE OF HOUSEHOLD GOODS AND PROFESSIONAL BOOKS, PAPERS, AND EQUIPMENT (PBP&E) Commuted Rate § 302-7.102 How is the mileage distance determined under the commuted...
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
... PROPERTY 7-TRANSPORTATION AND TEMPORARY STORAGE OF HOUSEHOLD GOODS AND PROFESSIONAL BOOKS, PAPERS, AND EQUIPMENT (PBP&E) Commuted Rate § 302-7.102 How is the mileage distance determined under the commuted...
41 CFR 302-7.102 - How is the mileage distance determined under the commuted rate method?
Code of Federal Regulations, 2012 CFR
2012-07-01
... PROPERTY 7-TRANSPORTATION AND TEMPORARY STORAGE OF HOUSEHOLD GOODS AND PROFESSIONAL BOOKS, PAPERS, AND EQUIPMENT (PBP&E) Commuted Rate § 302-7.102 How is the mileage distance determined under the commuted...
41 CFR 302-7.102 - How is the mileage distance determined under the commuted rate method?
Code of Federal Regulations, 2013 CFR
2013-07-01
... PROPERTY 7-TRANSPORTATION AND TEMPORARY STORAGE OF HOUSEHOLD GOODS AND PROFESSIONAL BOOKS, PAPERS, AND EQUIPMENT (PBP&E) Commuted Rate § 302-7.102 How is the mileage distance determined under the commuted...
Impacts on air pollution and health by changing commuting from car to bicycle.
Johansson, Christer; Lövenheim, Boel; Schantz, Peter; Wahlgren, Lina; Almström, Peter; Markstedt, Anders; Strömgren, Magnus; Forsberg, Bertil; Sommar, Johan Nilsson
2017-04-15
Our study is based on individual data on people's home and work addresses, as well as their age, sex and physical capacity, in order to establish realistic bicycle-travel distances. A transport model is used to single out data on commuting preferences in the County Stockholm. Our analysis shows there is a very large potential for reducing emissions and exposure if all car drivers living within a distance corresponding to a maximum of a 30min bicycle ride to work would change to commuting by bicycle. It would result in >111,000 new cyclists, corresponding to an increase of 209% compared to the current situation. Mean population exposure would be reduced by about 7% for both NOx and black carbon (BC) in the most densely populated area of the inner city of Stockholm. Applying a relative risk for NOx of 8% decrease in all-cause mortality associated with a 10μgm(-3) decrease in NOx, this corresponds to >449 (95% CI: 340-558) years of life saved annually for the Stockholm county area with 2.1 million inhabitants. This is more than double the effect of the reduced mortality estimated for the introduction of congestion charge in Stockholm in 2006. Using NO2 or BC as indicator of health impacts, we obtain 395 (95% CI: 172-617) and 185 (95% CI: 158-209) years of life saved for the population, respectively. The calculated exposure of BC and its corresponding impacts on mortality are likely underestimated. With this in mind the estimates using NOx, NO2 and BC show quite similar health impacts considering the 95% confidence intervals. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
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.
A Dream of Yukawa — Non-Local Fields out of Non-Commutative Spacetime —
NASA Astrophysics Data System (ADS)
Naka, Shigefumi; Toyoda, Haruki; Takanashi, Takahiro; Umezawa, Eizo
The coordinates of κ-Minkowski spacetime form Lie algebraic elements, in which time and space coordinates do not commute in spite of that space coordinates commute each other. The non-commutativity is realized by a Planck-length-scale constant κ - 1( ne 0), which is a universal constant other than the light velocity under the κ-Poincare transformation. Such a non-commutative structure can be realized by SO(1,4) generators in dS4 spacetime. In this work, we try to construct a κ-Minkowski like spacetime with commutative 4-dimensional spacetime based on Adsn+1 spacetime. Another aim of this work is to study invariant wave equations in this spacetime from the viewpoint of non-local field theory by H. Yukawa, who expected to realize elementary particle theories without divergence according to this viewpoint.
Green Commuting in the Health Care Sector: Obstacles and Best Practices.
Kaplan, Susan; Ai, Ning; Orris, Peter; Sriraj, P S
2016-02-01
Fossil fuel transportation by health care providers contributes to the prevalence of diseases they treat. We conducted an exploratory study to understand obstacles to, and best practices for, greener commuting among health care providers. We surveyed staff of three hospital clinics as to how they commute and why, and interviewed key staff of five hospital leaders in green commuting about their programs. Factors that might change respondents' commuting choices from driving alone included financial incentives, convenience, and solutions to crime and safety concerns. Successful green commuting programs offer benefits including free or reduced transit passes, shuttle buses to transit stations, and free emergency rides home. Exemplary programs throughout the country demonstrate that modifying those factors within reach can impact the amount of fossil fuel energy used for health care provider transportation.
A reconstruction theorem for Connes-Landi deformations of commutative spectral triples
NASA Astrophysics Data System (ADS)
Ćaćić, Branimir
2015-12-01
We formulate and prove an extension of Connes's reconstruction theorem for commutative spectral triples to so-called Connes-Landi or isospectral deformations of commutative spectral triples along the action of a compact Abelian Lie group G, also known as toric noncommutative manifolds. In particular, we propose an abstract definition for such spectral triples, where noncommutativity is entirely governed by a deformation parameter sitting in the second group cohomology of the Pontryagin dual of G, and then show that such spectral triples are well-behaved under further Connes-Landi deformation, thereby allowing for both quantisation from and dequantisation to G-equivariant abstract commutative spectral triples. We then use a refinement of the Connes-Dubois-Violette splitting homomorphism to conclude that suitable Connes-Landi deformations of commutative spectral triples by a rational deformation parameter are almost-commutative in the general, topologically non-trivial sense.
Topological expansion of the Bethe ansatz, and non-commutative algebraic geometry
NASA Astrophysics Data System (ADS)
Eynard, B.; Marchal, O.
2009-03-01
In this article, we define a non-commutative deformation of the ``symplectic invariants'' (introduced in [13]) of an algebraic hyperelliptic plane curve. The necessary condition for our definition to make sense is a Bethe ansatz. The commutative limit reduces to the symplectic invariants, i.e. algebraic geometry, and thus we define non-commutative deformations of some algebraic geometry quantities. In particular our non-commutative Bergman kernel satisfies a Rauch variational formula. Those non-commutative invariants are inspired from the large N expansion of formal non-hermitian matrix models. Thus they are expected to be related to the enumeration problem of discrete non-orientable surfaces of arbitrary topologies.
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.
NASA Astrophysics Data System (ADS)
Ham, Walter; Vijayan, Abhilash; Schulte, Nico; Herner, Jorn D.
2017-10-01
This study was designed to estimate and compare the air pollution exposures experienced by commuters in six common transportation modes utilized by California residents, and to evaluate the impact of practical exposure mitigation strategies in reducing commute exposures. We measured concentrations of fine particle matter (PM2.5), black carbon (BC), and ultrafine particles (UFP) for 161 commutes between April 2014 and November 2015 in Sacramento, CA. We collected measurements for six modes including single occupancy vehicles, high occupancy vehicles (multiple occupants), buses, light rail, train, and bicycling. The largest average concentrations for most pollutants were measured during train commutes and the lowest average concentrations were observed during light-rail commutes. Mitigation options were explored for personal vehicles, bicycling, and train commute modes. We found that ventilation settings of personal vehicles can reduce in-vehicle PM2.5, BC, and UFP concentrations by up to 75%. Similarly, bicycle route choice can reduce exposures by 15-75% with the lowest concentrations observed during commutes on dedicated bicycle paths away from traffic sources. Train commuters experienced UFP concentrations an order of magnitude greater when the locomotive engine was pulling the rail cars versus pushing the rail cars. We found that UFP concentrations during bus, bicycling, and train commutes were 1.6-5.3 times greater than personal vehicle commutes, while light rail commutes had 30% lower UFP concentrations than personal vehicle commutes. The largest exposure per mile occurred during bicycle commutes with PM2.5, BC, and UFP exposures of 1.312 μg/mile, 0.097 μg/mile, and 3.0 × 109 particles/mile, respectively. Train commutes experienced the largest exposure per mile of all of the combustion-derived transportation commute modes. BC accounted for 5-20% of total PM mass across all commute modes with an average fraction of ∼7% of PM2.5.
Exploring Universal Patterns in Human Home-Work Commuting from Mobile Phone Data
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
Bicycle commuter injury prevention: it is time to focus on the environment.
Hoffman, Melissa R; Lambert, William E; Peck, Ellen G; Mayberry, John C
2010-11-01
Few data exist on the risk of injury while commuting to work or school by bicycle. The proportion of commuters choosing to travel by bike is increasing in the United States, and information on injury incidence and the influences of rider characteristics and environmental factors may suggest opportunities for prevention actions. Bicycle commuters in the Portland, OR, metropolitan area were recruited via the websites and community advertising to participate in a 1-year study. Riders completed an initial online survey along with 12 monthly surveys describing their commutes and injury events from September 2007 to August 2008. A traumatic event was considered a serious traumatic event if medical attention was sought. Nine hundred sixty-two adult bicyclists (52% men and 48% women) with a mean age of 36.7 ± 0.4 years (range, 22-70 years) commuted an average of 135 miles (range, 7-617) per month. There were 225 (23%) beginner, 256 (27%) intermediate, and 481 (50%) advanced riders. Four hundred twenty (44%) had a prior traumatic event. Over the 1-year period, 164 (18%) riders reported 192 traumatic events and 49 (5%) reported 50 serious traumatic events. The incidence rates of traumatic events and serious traumatic events were 15.0 (95% CI, 13.2-17.5) and 3.9 (95% CI, 2.9-5.1) per 100,000 miles commuted. There were no differences in age, gender, safety practices, and experience levels between commuters who experienced a traumatic event and those who did not. Approximately 20% of bicycle commuters experienced a traumatic event and 5% required medical attention during 1 year of commuting. Traumatic events were not related to rider demographics, safety practices, or experience levels. These results imply that injury prevention should focus on improving the safety of the bicycle commuting environment.
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
Code of Federal Regulations, 2013 CFR
2013-10-01
... Hours of Service Requirements for Train Employees Engaged in Commuter or Intercity Rail Passenger Transportation § 228.405 Limitations on duty hours of train employees engaged in commuter or intercity rail... its officers and agents may not require or allow a train employee engaged in commuter or...
Code of Federal Regulations, 2014 CFR
2014-10-01
... Hours of Service Requirements for Train Employees Engaged in Commuter or Intercity Rail Passenger Transportation § 228.405 Limitations on duty hours of train employees engaged in commuter or intercity rail... its officers and agents may not require or allow a train employee engaged in commuter or...
Code of Federal Regulations, 2012 CFR
2012-10-01
... Hours of Service Requirements for Train Employees Engaged in Commuter or Intercity Rail Passenger Transportation § 228.405 Limitations on duty hours of train employees engaged in commuter or intercity rail... its officers and agents may not require or allow a train employee engaged in commuter or...
[Commuting of workers to the city of Zagreb--a contribution to the typology of spatial mobility].
Oliveira-roca, M
1986-01-01
The author studies trends in commuting to the city of Zagreb in Croatia, Yugoslavia. Commuter surveys and bivariate analysis are used to describe the socioeconomic level, occupational status, transportation method, and place of residence of rural and urban residents who commute to the city. (SUMMARY IN ENG AND RUS)
Criterion distances and environmental correlates of active commuting to school in children
2011-01-01
Background Active commuting to school can contribute to daily physical activity levels in children. Insight into the determinants of active commuting is needed, to promote such behavior in children living within a feasible commuting distance from school. This study determined feasible distances for walking and cycling to school (criterion distances) in 11- to 12-year-old Belgian children. For children living within these criterion distances from school, the correlation between parental perceptions of the environment, the number of motorized vehicles per family and the commuting mode (active/passive) to school was investigated. Methods Parents (n = 696) were contacted through 44 randomly selected classes of the final year (sixth grade) in elementary schools in East- and West-Flanders. Parental environmental perceptions were obtained using the parent version of Neighborhood Environment Walkability Scale for Youth (NEWS-Y). Information about active commuting to school was obtained using a self-reported questionnaire for parents. Distances from the children's home to school were objectively measured with Routenet online route planner. Criterion distances were set at the distance in which at least 85% of the active commuters lived. After the determination of these criterion distances, multilevel analyses were conducted to determine correlates of active commuting to school within these distances. Results Almost sixty percent (59.3%) of the total sample commuted actively to school. Criterion distances were set at 1.5 kilometers for walking and 3.0 kilometers for cycling. In the range of 2.01 - 2.50 kilometers household distance from school, the number of passive commuters exceeded the number of active commuters. For children who were living less than 3.0 kilometers away from school, only perceived accessibility by the parents was positively associated with active commuting to school. Within the group of active commuters, a longer distance to school was associated with
The effects of commuter pedestrian traffic on the use of stairs in an urban setting.
Andersen, Ross E; Bauman, Adrian E
2011-01-01
Most public health physical activity guidelines now encourage people to look for opportunities to accumulate physical activity throughout the day. Climbing stairs in lieu of riding escalators is a prime opportunity to make healthier choices that promote active living. The purpose of this investigation was to examine the effects of pedestrian commuter traffic on choices to ride an escalator, walk up an escalator, or walk up adjacent stairs in a busy urban subway station at rush hour. A total of 9766 commuters were observed by two recorders for a 2.5-hour period during the morning rush hour over 8 weeks as to whether the commuters walked up stairs or rode an adjacent escalator in a subway station. The number of observations per 5-minute block was recorded, and an index of commuter traffic was computed. Demographic information and use of escalators/stairs were also recorded. An urban subway station with a two-flight staircase adjacent to an escalator. Adult commuters travelling to work during the morning rush hour. Physical activity choices were examined in relation to commuter traffic. Demographic information, such as age, race, and weight status, were also considered. A χ(2) analysis was used to examine differences in proportions across variables of interest. Means were compared by using multivariate analysis of variance, and confidence intervals were computed. During the least-heavy commuter traffic period, only 11.2% of commuters chose to walk up the stairs, whereas significantly more did so during moderate 18.7% and high 20.8% commuter traffic periods (χ(2) = 61.8, p < .001). During low-traffic times, significantly more commuters (21.4%) walked up the escalators compared with moderate-traffic (18.0%) or high-traffic (18.3%) periods. African-American commuters passively rode the escalator more (68.2%) than white commuters (56.7%), and their patterns were less affected by commuter traffic (p < .05). Congestion in public places can have a significant effect
Mixed-state fidelity susceptibility through iterated commutator series expansion.
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.
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.
Adaptive control system for line-commutated inverters
NASA Technical Reports Server (NTRS)
Dolland, C. R.; Bailey, D. A. (Inventor)
1983-01-01
A control system for a permanent magnet motor driven by a multiphase line commutated inverter is provided with integration for integrating the back EMF of each phase of the motor. This is used in generating system control signals for an inverter gate logic using a sync and firing angle (alpha) control generator connected to the outputs of the integrators. A precision full wave rectifier provides a speed control feedback signal to a phase delay rectifier via a gain and loop compensation circuit and to the integrators for adaptive control of the attenuation of low frequencies by the integrators as a function of motor speed. As the motor speed increases, the attenuation of low frequency components by the integrators is increased to offset the gain of the integrators to spurious low frequencies.
QED commutation relations for inhomogeneous Kramers-Kronig dielectrics
NASA Astrophysics Data System (ADS)
Scheel, Stefan; Knöll, Ludwig; Welsch, Dirk-Gunnar
1998-07-01
Recently a quantization scheme for the phenomenological Maxwell theory of the full electromagnetic field in an inhomogeneous three-dimensional, dispersive, and absorbing dielectric medium has been developed and applied to a system consisting of two infinite half-spaces with a common planar interface (H.T. Dung, L. Knöll, and D.-G. Welsch, Phys. Rev. A 57, 3931 (1998)). Here we show that the scheme, which is based on the classical Green-tensor integral representation of the electromagnetic field, applies to any inhomogeneous medium. For this purpose we prove that the fundamental equal-time commutation relations of QED are preserved for an arbitrarily space-dependent, Kramers-Kronig consistent permittivity. Further, an extension of the quantization scheme to linear media with bounded regions of amplification is given, and the problem of anisotropic media is briefly addressed.
Counting Unstable Eigenvalues in Hamiltonian Spectral Problems via Commuting Operators
NASA Astrophysics Data System (ADS)
Haragus, Mariana; Li, Jin; Pelinovsky, Dmitry E.
2017-08-01
We present a general counting result for the unstable eigenvalues of linear operators of the form J L in which J and L are skew- and self-adjoint operators, respectively. Assuming that there exists a self-adjoint operator K such that the operators J L and J K commute, we prove that the number of unstable eigenvalues of J L is bounded by the number of nonpositive eigenvalues of K. As an application, we discuss the transverse stability of one-dimensional periodic traveling waves in the classical KP-II (Kadomtsev-Petviashvili) equation. We show that these one-dimensional periodic waves are transversely spectrally stable with respect to general two-dimensional bounded perturbations, including periodic and localized perturbations in either the longitudinal or the transverse direction, and that they are transversely linearly stable with respect to doubly periodic perturbations.
On the Path Integral in Non-Commutative (nc) Qft
NASA Astrophysics Data System (ADS)
Dehne, Christoph
2008-09-01
As is generally known, different quantization schemes applied to field theory on NC spacetime lead to Feynman rules with different physical properties, if time does not commute with space. In particular, the Feynman rules that are derived from the path integral corresponding to the T*-product (the so-called naïve Feynman rules) violate the causal time ordering property. Within the Hamiltonian approach to quantum field theory, we show that we can (formally) modify the time ordering encoded in the above path integral. The resulting Feynman rules are identical to those obtained in the canonical approach via the Gell-Mann-Low formula (with T-ordering). They preserve thus unitarity and causal time ordering.
Upper bound for the length of commutative algebras
NASA Astrophysics Data System (ADS)
Markova, Ol'ga V.
2009-12-01
By the length of a finite system of generators for a finite-dimensional associative algebra over an arbitrary field one means the least positive integer k such that the words of length not exceeding k span this algebra (as a vector space). The maximum length for the systems of generators of an algebra is referred to as the length of the algebra. In the present paper, an upper bound for the length of a commutative algebra in terms of a function of two invariants of the algebra, the dimension and the maximal degree of the minimal polynomial for the elements of the algebra, is obtained. As a corollary, a formula for the length of the algebra of diagonal matrices over an arbitrary field is obtained. Bibliography: 8 titles.
Upper bound for the length of commutative algebras
Markova, Ol'ga V
2009-12-31
By the length of a finite system of generators for a finite-dimensional associative algebra over an arbitrary field one means the least positive integer k such that the words of length not exceeding k span this algebra (as a vector space). The maximum length for the systems of generators of an algebra is referred to as the length of the algebra. In the present paper, an upper bound for the length of a commutative algebra in terms of a function of two invariants of the algebra, the dimension and the maximal degree of the minimal polynomial for the elements of the algebra, is obtained. As a corollary, a formula for the length of the algebra of diagonal matrices over an arbitrary field is obtained. Bibliography: 8 titles.
Commutative deformations of general relativity: nonlocality, causality, and dark matter
NASA Astrophysics Data System (ADS)
de Vegvar, P. G. N.
2017-01-01
Hopf algebra methods are applied to study Drinfeld twists of (3+1)-diffeomorphisms and deformed general relativity on commutative manifolds. A classical nonlocality length scale is produced above which microcausality emerges. Matter fields are utilized to generate self-consistent Abelian Drinfeld twists in a background independent manner and their continuous and discrete symmetries are examined. There is negligible experimental effect on the standard model of particles. While baryonic twist producing matter would begin to behave acausally for rest masses above {˜ }1-10 TeV, other possibilities are viable dark matter candidates or a right-handed neutrino. First order deformed Maxwell equations are derived and yield immeasurably small cosmological dispersion and produce a propagation horizon only for photons at or above Planck energies. This model incorporates dark matter without any appeal to extra dimensions, supersymmetry, strings, grand unified theories, mirror worlds, or modifications of Newtonian dynamics.
Complexity and non-commutativity of learning operations on graphs.
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.
Commuter motorcycle crashes in Malaysia: An understanding of contributing factors.
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.
Quantum groups, non-commutative differential geometry and applications
Schupp, Peter
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.
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%.
Commuter motorcycle crashes in Malaysia: An understanding of contributing factors
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
Simulation of Population-Based Commuter Exposure to NO2 Using Different Air Pollution Models
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
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
The Association between Access to Public Transportation and Self-Reported Active Commuting
Djurhuus, Sune; Hansen, Henning S.; Aadahl, Mette; Glümer, Charlotte
2014-01-01
Active commuting provides routine-based regular physical activity which can reduce the risk of chronic diseases. Using public transportation involves some walking or cycling to a transit stop, transfers and a walk to the end location and users of public transportation have been found to accumulate more moderate physical activity than non-users. Understanding how public transportation characteristics are associated with active transportation is thus important from a public health perspective. This study examines the associations between objective measures of access to public transportation and self-reported active commuting. Self-reported time spent either walking or cycling commuting each day and the distance to workplace were obtained for adults aged 16 to 65 in the Danish National Health Survey 2010 (n = 28,928). Access to public transportation measures were computed by combining GIS-based road network distances from home address to public transit stops an integrating their service level. Multilevel logistic regression was used to examine the association between access to public transportation measures and active commuting. Distance to bus stop, density of bus stops, and number of transport modes were all positively associated with being an active commuter and with meeting recommendations of physical activity. No significant association was found between bus services at the nearest stop and active commuting. The results highlight the importance of including detailed measurements of access to public transit in order to identify the characteristics that facilitate the use of public transportation and active commuting. PMID:25489998
Simulation of population-based commuter exposure to NO₂ using different air pollution models.
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.
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
Asymptotic Analysis of the Ponzano-Regge Model with Non-Commutative Metric Boundary Data
NASA Astrophysics Data System (ADS)
Oriti, Daniele; Raasakka, Matti
2014-06-01
We apply the non-commutative Fourier transform for Lie groups to formulate the non-commutative metric representation of the Ponzano-Regge spin foam model for 3d quantum gravity. The non-commutative representation allows to express the amplitudes of the model as a first order phase space path integral, whose properties we consider. In particular, we study the asymptotic behavior of the path integral in the semi-classical limit. First, we compare the stationary phase equations in the classical limit for three different non-commutative structures corresponding to the symmetric, Duflo and Freidel-Livine-Majid quantization maps. We find that in order to unambiguously recover discrete geometric constraints for non-commutative metric boundary data through the stationary phase method, the deformation structure of the phase space must be accounted for in the variational calculus. When this is understood, our results demonstrate that the non-commutative metric representation facilitates a convenient semi-classical analysis of the Ponzano-Regge model, which yields as the dominant contribution to the amplitude the cosine of the Regge action in agreement with previous studies. We also consider the asymptotics of the SU(2) 6j-symbol using the non-commutative phase space path integral for the Ponzano-Regge model, and explain the connection of our results to the previous asymptotic results in terms of coherent states.
The association between access to public transportation and self-reported active commuting.
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.
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.
NASA Astrophysics Data System (ADS)
Agee, Forrest J.; Davanloo, Farzin; Camase, Tiberius; Collins, Carl B., Jr.
2002-06-01
Photoconductive switching of the stacked Blumlein pulsers, developed at the Univ. of Texas at Dallas (UTD), currently produces high power, nanosecond pulses with risetimes on the order of 200 ps. The device has a compact geometry and is commutated by a single GaAs photoconductive semiconductor switch (PCSS) triggered by a low power laser diode array. Filamentation of the conductivity associated with high gain GaAs switches produces such high current density that the switches are damages near the metal-semiconductor interface and the lifetime is limited. The semiconductor properties of amorphic diamond can be employed to improve the PCSS longevity by coating the switch cathode or anode areas or both. For example if the switch cathode is coated, the tunneling of electrons from amorphic diamond to GaAs during the off-state stage of PCSS operation provides pre-avalanche sites that diffuse conduction current upon switch activation. This report presents the progress toward improving the high gain switch operation and lifetime by advanced treatments with amorphic diamond coatings. A significant improvement in switch lifetime is demonstrated by testing the diamond-coated switch performance in a stacked Blumlein prototype pulser.
NYPA/TH!NK Clean Commute Program Report – Inception Through May 2004
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.
NYPA/TH!NK Clean Commute Program Final Report - Inception through December 2004
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.
Active commuting to and from school among Swedish children--a national and regional study.
Johansson, Klara; Laflamme, Lucie; Hasselberg, Marie
2012-04-01
Active commuting to school by walking or cycling can have positive impact on children's health and development. The study investigates the prevalence of active commuting to school in Sweden, a setting where it is facilitated and promoted; and how active commuting varies according to socio-demographic and socio-economic characteristics. Self-reports from a national sample of Swedish children (11- to 15-year-olds, n = 4415) and a regional one from Stockholm County (13-year-olds, n = 1008) on transport to school were compared. The association that active commuting has with socio-demographic (gender, school grade, Swedish origin, type of housing, urbanicity in the local area), and socio-economic characteristics (household socio-economic status, family car ownership) was studied using logistic regression, controlling for car ownership and urbanicity, respectively. Active commuting was high (62.9% in the national sample) but decreased with age-76% at the age of 11 years, 62% at the age of 13 years and 50% at the age of 15 years-whereas public transport increased (19-43%). Living in an apartment or row-house (compared with detached house) and living in a medium-sized city (compared with a metropolitan area) was associated with active commuting. In urban areas, active commuting was more common in worker households compared with intermediate- to high-level salaried employees. Active commuting is common but decreases with age. Active commuting differed based on housing and urbanicity but not based on gender or Swedish origin, and impact of socio-economic factors differed depending on level of urbanicity.
Private and public modes of bicycle commuting: a perspective on attitude and perception.
Curto, A; de Nazelle, A; Donaire-Gonzalez, D; Cole-Hunter, T; Garcia-Aymerich, J; Martínez, D; Anaya, E; Rodríguez, D; Jerrett, M; Nieuwenhuijsen, M J
2016-08-01
Public bicycle-sharing initiatives can act as health enhancement strategies among urban populations. The aim of the study was to determine which attitudes and perceptions of behavioural control toward cycling and a bicycle-sharing system distinguish commuters with a different adherence to bicycle commuting. The recruitment process was conducted in 40 random points in Barcelona from 2011 to 2012. Subjects completed a telephone-based questionnaire including 27 attitude and perception statements. Based on their most common one-way commute trip and willingness to commute by bicycle, subjects were classified into Private Bicycle (PB), public bicycle or Bicing Bicycle (BB), Willing Non-bicycle (WN) and Non-willing Non-bicycle (NN) commuters. After reducing the survey statements through principal component analysis, a multinomial logistic regression model was obtained to evaluate associations between attitudinal and commuter sub-groups. We included 814 adults in the analysis [51.6% female, mean (SD): age 36.6 (10.3) years]. BB commuters were 2.0 times [95% confidence interval (CI) = 1.1-3.7] less likely to perceive bicycle as a quick, flexible and enjoyable mode compared to PB. BB, WN and NN were 2.5 (95% CI = 1.46-4.24), 2.6 (95% CI = 1.53-4.41) and 2.3 times (95% CI = 1.30-4.10) more likely to perceive benefits of using public bicycles (bicycle maintenance and parking avoidance, low cost and no worries about theft and vandalism) than did PB. Willing non-bicycle and public-bicycle commuters had more favourable perception toward public-shared bicycles compared to private cyclists. Hence, public bicycles may be the impetus for those willing to start bicycle commuting, thereby increasing physical activity levels. © The Author 2016. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.
Martinez-Gomez, David; Mielke, Gregore I.; Menezes, Ana M.; Gonçalves, Helen; Barros, Fernando C.; Hallal, Pedro C.
2014-01-01
Background Active commuting is a good opportunity to accumulate physical activity (PA) across the lifespan that potentially might influence central body fat. We aimed to examine the prospective associations of active commuting at 11, 15 and 18 years of age with central body fat at 18 years. Methods Participants were part of a large birth cohort study in Pelotas, Brazil (n = 3,649 participants). Active commuting, leisure-time PA and income were self-reported at 11, 15 and 18 years. Waist circumference and trunk fat mass were collected at 18 years with the use of a 3-dimensional photonic scanner and dual-energy X-ray absorptiometry, respectively. Results Active commuting at 11 years was not prospectively associated with central body fat. However, we found that active commuting at 15 and 18 years were prospectively and cross-sectionally associated with central body fat variables, respectively, in boys but not in girls. Also, boys in the highest tertile of accumulated active commuting (i.e., average of active commuting at 11, 13 and 18 years) were associated with −2.09 cm (95%CI: −3.24; −0.94) of waist circumference and −1.11 kg (95%CI: −1.74; −0.48) of trunk fat mass compared to boys in the lowest tertile. Analyses on changes in tertiles of active commuting from 11 and 15 years to 18 years with central body fat variables at 18 years showed that boys who remained consistently in the highest tertile or moved to a higher tertile had lower levels of central body fat compared to those consistently in the lowest tertile. Conclusions Active commuting throughout adolescence in boys, especially during middle and late adolescence, is associated with lower levels in central fatness before adulthood. PMID:24791780
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.
Yang, Lin; Hipp, J. Aaron; Adlakha, Deepti; Marx, Christine M.; Tabak, Rachel G.; Brownson, Ross C.
2015-01-01
Background Promoting the use of public transit and active transport (walking and cycling) instead of car driving is an appealing strategy to increase overall physical activity. Purpose To quantify the combined associations between self-reported home and worksite neighborhood environments, worksite support and policies, and employees’ commuting modes. Method Between 2012 and 2013, participants residing in four Missouri metropolitan areas were interviewed via telephone (n = 1,338) and provided information on socio-demographic characteristics, home and worksite neighborhoods, and worksite support and policies. Commuting mode was self-reported and categorized into car driving, public transit, and active commuting. Commuting distance was calculated using geographic information systems. Commuters providing completed data were included in the analysis. Multivariate logistic regression models were used to examine the correlates of using public transit and active commuting. Result The majority of participants reported commuting by driving (88.9%); only 4.9% used public transit and 6.2% used active modes. After multivariate adjustment, having transit stops within 10-15 minutes walking distance from home (p=0.05) and using worksite incentive for public transit (p<0.001) were associated with commuting by public transit. Commuting distance (p<0.001) was negatively associated with active commuting. Having free or low cost recreation facilities around the worksite (p=0.04) and using bike facilities to lock bikes at the worksite (p<0.001) were associated with active commuting. Conclusion Both environment features and worksite supports and policies are associated with the choice of commuting mode. Future studies should use longitudinal designs to investigate the potential of promoting alternative commuting modes through worksite efforts that support sustainable commuting behaviors as well as the potential of built environment improvements. PMID:26085979
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.
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.
Commute trip reduction in Washington: Base year worksite characteristics and programs
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.
77 FR 72432 - Application of Boutique Air, Inc. for Commuter Air Carrier Authority
Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-05
... Department of Transportation is directing all interested persons to show cause why it should not issue an order finding Boutique Air, Inc., fit, willing, and able, and awarding it commuter air carrier authority...
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Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-23
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-11
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78 FR 72972 - Application of Ultimate JETCHARTERS, LLC for Commuter Air Carrier Authority
Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-04
...: The Department of Transportation is directing all interested persons to show cause why it should not issue an order finding Ultimate JETCHARTERS, LLC, fit, willing, and able, and awarding it commuter air...
Commuter networks and community detection: A method for planning sub regional areas
NASA Astrophysics Data System (ADS)
De Montis, Andrea; Caschili, Simone; Chessa, Alessandro
2013-01-01
A major issue for policy makers and planners is the definition of "ideal" regional partitions, i.e. the delimitation of sub-regional domains showing a sufficient level of homogeneity with respect to some specific territorial features. In this paper, we compare some intermediate body partitions of Sardinia, Italy, with patterns that emerge from the workers and students' commuting. We apply grouping methodologies based on the characterization of Sardinian commuting system as a complex weighted network. We adopt an algorithm based on the maximization of the weighted modularity of this network and detect productive basins composed by municipalities with degree of cohesiveness in terms of commuters' flows. The results of this study lead us to conclude that the recently instituded provinces in Sardinia have been designed -even unconsciously- as labour basins of municipalities with similar commuting behaviour.
NASA Astrophysics Data System (ADS)
Devi, M. K.
2017-06-01
In order to alleviate the negative impacts of motorized vehicle use as well as create sustainable environment within campus area, it is pivotal to encourage mode shifting among university students. Active transport modes such as walking, cycling, and using public transport can be considered as alternative modes. This paper tried to identify the potential to increase active commuting in UGM by understanding student’s travel behavior. ANOVA test was employed to identify the perceptions between students across residential zones toward motivators and barriers to actively commute. The findings were used to propose strategies for increasing active commuting level in UGM, which are: reducing barriers to actively commute, improving public transport services, improving walking and cycling facilities, and introducing programs to discourage motorized vehicle use.
Daily time budgets of long-distance commuting workers in Tokyo megalopolis.
Umezaki, M; Ishimaru, H; Ohtsuka, R
1999-01-01
In Tokyo Megalopolis, long-distance commuting between residences in the suburbs and work places in the centre of the city was examined. Using a questionnaire, heads of household in two suburbs were asked about the influences of long commuting hours on their daily time budgets. The results showed that on workdays, the workers who spent longer commuting rose and left home for work earlier, and came back home and retired later; accordingly, both time spent on in-home activities on workdays and hours slept on the day before a workday were shorter. Comparison of time budgets between the subjects who work 5 and 6 days per week revealed more vulnerable influences of long commuting hours in the former than the latter. The expected health consequences of these findings are discussed from a biosocial/human ecological viewpoint.
Explicit derivation of Yang-Mills self-dual solutions on non-commutative harmonic space
NASA Astrophysics Data System (ADS)
Belhaj, A.; Hssaini, M.; Sahraoui, E. M.; Saidi, E. H.
2001-06-01
We develop the non-commutative harmonic space (NHS) analysis to study the problem of solving the nonlinear constraint equations of non-commutative Yang-Mills self-duality in four dimensions. We show that this space, denoted also as NHS(η,θ), has two SU(2) isovector deformations η(ij) and θ(ij) parametrizing, respectively, two non-commutative harmonic subspaces NHS(η,0) and NHS(0, θ) used to study the self-dual and anti self-dual non-commutative Yang-Mills solutions. We reformulate the Yang-Mills self-dual constraint equations on NHS(η,0) by extending the idea of harmonic analyticity to linearize them. We then give a perturbative self-dual solution recovering the ordinary one. Finally, we present the explicit computation of an exact self-dual solution.
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.
NASA Technical Reports Server (NTRS)
Davis, D. J.; Linse, D. J.; Suikat, R.; Entz, D. P.
1986-01-01
The continued investigation of the design of Ride Quality Augmentation Systems (RQAS) for commuter aircraft is described. The purpose of these RQAS is the reduction of the vertical and lateral acceleration response of the aircraft due to atmospheric turbulence by the application of active control. The current investigations include the refinement of the sample data feedback control laws based on the control-rate-weighting and output-weighting optimal control design techniqes. These control designs were evaluated using aircraft time simulations driven by Dryden spectra turbulence. Fixed gain controllers were tested throughout the aircrft operating envelope. The preliminary design of the hardware modifications necessary to implement and test the RQAS on a commuter aircraft is included. These include a separate surface elevator and the flap modifications to provide both direct lift and roll control. A preliminary failure mode investigation was made for the proposed configuration. The results indicate that vertical acceleration reductions of 45% and lateral reductions of more than 50% are possible. A fixed gain controller appears to be feasible with only minor response degradation.
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.
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.
2011-01-01
Background The need for a mobile workforce inevitably means that the length of the total work day (working and traveling time) will increase, but the health effects of commuting have been surprisingly little studied apart from perceived stress and the benefits of physically active commuting. Methods We used data from two cross-sectional population-based public health surveys performed in 2004 and 2008 in Scania, Sweden (56% response rate). The final study population was 21, 088 persons aged 18-65, working > 30 h/week. Duration (one-way) and mode of commuting were reported. The outcomes studied were perceived poor sleep quality, everyday stress, low vitality, mental health, self-reported health, and absence from work due to sickness during the past 12 months. Covariates indicating socioeconomic status and family situation, overtime, job strain and urban/rural residency were included in multivariate analyses. Subjects walking or cycling to work < 30 min were used as a reference category. Results Monotonous relations were found between duration of public transport commuting and the health outcomes. For the category commuting > 60 min odds ratios (ORs) ranged from 1.2 - 1.6 for the different outcomes. For car commuting, the relationships were concave downward or flat, with increasing subjective health complaints up to 30-60 min (ORs ranging from 1.2 - 1.4), and lower ORs in the > 60 min category. A similar concave downward relationship was observed for sickness absence, regardless of mode of transport. Conclusions The results of this study are concordant with the few earlier studies in the field, in that associations were found between commutation and negative health outcomes. This further demonstrates the need to consider the negative side-effects of commuting when discussing policies aimed at increasing the mobility of the workforce. Studies identifying population groups with increased susceptibility are warranted. PMID:22039952
Commutability of Reference Materials for α-Fetoprotein in Human Serum.
Yue, Yuhong; Zhang, Shunli; Xu, Zhenzhen; Chen, Xi; Wang, Qingtao
2017-10-01
- Reliable quantification of α-fetoprotein (AFP) is critical for clinical diagnosis. Accuracy in AFP analysis relies on traceability to reference materials with confirmed commutability. - To assess the commutability of the reference materials for AFP. We screened for appropriate reference materials for the calibration of clinical AFP analysis and for application in an external quality assessment scheme. The feasibility of using water to dilute a reference material from the World Health Organization was also evaluated. - Patient serum samples with various levels of AFP were randomly interspersed among AFP reference materials from the World Health Organization, the Beijing Center for Clinical Laboratories, and Beijing Controls and Standards Biotechnology and quality controls from Bio-Rad. The samples were analyzed on 5 different platforms to assess the comparability of the results and commutability of the reference materials. - Significant variations in AFP measurement were observed among the 5 instrument platforms. The Beijing Center for Clinical Laboratories and Beijing Controls and Standards Biotechnology reference materials were commutable across all the instrument platforms. The World Health Organization AFP 72/225 reference material diluted with distilled water was also commutable at high concentrations. The Bio-Rad quality control materials for AFP were commutable among 4 out of 5 instrument platforms. - Our results suggested that the Beijing Center for Clinical Laboratories and Beijing Controls and Standards Biotechnology materials were commutable across all 5 instrument platforms, whereas the Bio-Rad quality controls were limited by the concentration of AFP and the instrument platforms used. Caution needs to be taken in using water to dilute the World Health Organization 72/225 reference material because its commutability is limited to high concentrations.
Yao, Xing-Can; Fiurásek, Jaromír; Lu, He; Gao, Wei-Bo; Chen, Yu-Ao; Chen, Zeng-Bing; Pan, Jian-Wei
2010-09-17
We experimentally demonstrate an advanced linear-optical programmable quantum processor that combines two elementary single-qubit programmable quantum gates. We show that this scheme enables direct experimental probing of quantum commutation relations for Pauli operators acting on polarization states of single photons. Depending on a state of two-qubit program register, we can probe either commutation or anticommutation relations. Very good agreement between theory and experiment is observed, indicating high-quality performance of the implemented quantum processor.
Quantization maps, algebra representation, and non-commutative Fourier transform for Lie groups
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.
Modeling the Commuting Travel Activities within Historic Districts in Chinese Cities
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
Modeling the commuting travel activities within historic districts in Chinese cities.
Ye, Mao; Yu, Miao; Li, Zhibin; 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.
Perceptions of air pollution during the work-related commute by adults in Queensland, Australia
NASA Astrophysics Data System (ADS)
Badland, Hannah M.; Duncan, Mitch J.
2009-12-01
BackgroundThis study examines perceived health effect risks from air pollution during the work-related commute by socio-demographic and travel mode variables. MethodsPopulation-representative survey data were collected by telephone from 745 adults from Queensland, Australia. Variables assessed included socio-demographics, usual work travel mode, commute perceptions, and perceived health effects associated with air pollution during the work-related commute. ResultsApproximately 45% of the sample perceived air pollution negatively affected health outcomes when commuting to/from work, yet only 13% recognised air pollution as a major barrier to walking or cycling to/from work. No relationships existed between usual travel mode to/from work and perceived health risks associated with air pollution. Those higher educated or living in major cities were more likely to recognise air pollution harmed their health during their work-related commute when compared to respective referent categories ( p ≤ 0.05). ConclusionsRecognition of health risks from air pollution during the work-related commute was high, and awareness did not differ by travel mode. For the majority, air pollution was not a primary barrier for walking or cycling to/from work.
Wahlgren, Lina; Schantz, Peter
2014-01-01
Background and Aim: Commuting by bicycle could contribute to public health, and route environments may influence this behaviour. Therefore, the aim of this study is to assess the potential associations between appraisals of the overall route environment as hindering or stimulating for bicycle commuting, with both perceptions of commuting route environmental factors in a suburban area and background factors. Methods: The Active Commuting Route Environment Scale (ACRES) was used for the assessment of bicycle commuters’ perceptions and appraisals of their route environments in the suburban parts of Greater Stockholm, Sweden. A simultaneous multiple regression analysis was used to assess the relationship between the outcome variable whether the overall route environment hinders or stimulates bicycle commuting and environmental factors (e.g., exhaust fumes, speeds of motor vehicles, greenery), as well as background factors (sex, age, education, income) as predictor variables. Results and Conclusions: The results indicate that in suburban areas, the factors aesthetics, greenery and bicycle paths seem to be, independently of each other, stimulating factors for bicycle commuting. On the other hand, flows of motor vehicles, noise, and low “directness” of the route seem to be hindering factors. A comparison of these results with those obtained from an inner urban area points to the importance of studying different types of built-up areas separately. PMID:25153462
Vehicular emission exposure of bicycle commuters in the urban area of Guangzhou, South China (PRC)
Chan, L.Y.; Hung, W.T. ); Qin, Y. )
1994-01-01
Guangzhou is a major city in South China and is at the forefront of economic reform since 1978. The population of Guangzhou is rapidly increasing and most people either walk or cycle to and from work. These commuters are highly vulnerable to vehicular emissions. An indirect approach was adopted to estimate vehicular emission exposure to Guangzhou bicycle commuters. Four bus routes were selected as typical commuting routes. Concentrations of NO[sub x] and CO as well as traffic volume, vehicle speed, ground-level wind speed, and direction were measured at monitoring points set up along the routes of typical street links passing through areas of various land uses. CO and NO[sub x] were recognized to be two major vehicular emission pollutants. The average CO exposure levels of Guangzhou bicycle commuters ranged from 3.7 [mu]L/L to 8.2 [mu]L/L. Few CO samples exceeded the Chinese national assessment standard. No adverse effect on health was expected. The average NO[sub x] exposure levels of Guangzhou bicycle commuters ranged from 0.13 [mu]L/L to 0.26 [mu]L/L. More than half of the NO[sub x] samples exceeded the Chinese national assessment standard. Adverse effects on the health of bicycle commuters might result. Other factors such as street configurations and land uses were also analyzed. 15 refs., 5 figs., 4 tabs.
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.
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.
Psychosocial and environmental correlates of active commuting for university students.
Molina-García, Javier; Castillo, Isabel; Sallis, James F
2010-08-01
To examine psychosocial and environmental correlates of active commuting to university (ACU) and explore its association with overall physical activity among college students. The sample included 518 students (mean 22.4 years; 59.7% female) from two universities in Valencia, Spain. Weekly estimations of energy expenditure from ACU and total physical activity were obtained. Socio-economic status, self-efficacy, barriers to active transport, access to car and motorbike, access to public transport, walking and cycling facilities and distance to university were assessed. Data were collected April and May of 2009, using a self-administered survey. A structural equation model was used to analyze associations among variables. ACU was inversely correlated with access to private motorized transport (car or motorbike). Perception of physical self-efficacy and walking and cycling facilities were positively associated with ACU, while planning/psychosocial barriers were negatively associated. Multivariate modelling explained 19% of variance in ACU. ACU was not related to total daily physical activity. Both psychological and environmental variables were significant correlates of ACU. Present findings provide an empirical basis for interventions to increase active transport among university students. Copyright 2010 Elsevier Inc. All rights reserved.
Problem of quantifying quantum correlations with non-commutative discord
NASA Astrophysics Data System (ADS)
Majtey, A. P.; Bussandri, D. G.; Osán, T. M.; Lamberti, P. W.; Valdés-Hernández, A.
2017-09-01
In this work we analyze a non-commutativity measure of quantum correlations recently proposed by Guo (Sci Rep 6:25241, 2016). By resorting to a systematic survey of a two-qubit system, we detected an undesirable behavior of such a measure related to its representation-dependence. In the case of pure states, this dependence manifests as a non-satisfactory entanglement measure whenever a representation other than the Schmidt's is used. In order to avoid this basis-dependence feature, we argue that a minimization procedure over the set of all possible representations of the quantum state is required. In the case of pure states, this minimization can be analytically performed and the optimal basis turns out to be that of Schmidt's. In addition, the resulting measure inherits the main properties of Guo's measure and, unlike the latter, it reduces to a legitimate entanglement measure in the case of pure states. Some examples involving general mixed states are also analyzed considering such an optimization. The results show that, in most cases of interest, the use of Guo's measure can result in an overestimation of quantum correlations. However, since Guo's measure has the advantage of being easily computable, it might be used as a qualitative estimator of the presence of quantum correlations.
Computational quantum-classical boundary of noisy commuting quantum circuits
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
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).
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.
Computational quantum-classical boundary of noisy commuting quantum circuits.
Fujii, Keisuke; Tamate, Shuhei
2016-05-18
It is often said that the transition from quantum to classical worlds is caused by decoherence originated from an interaction between a system of interest and its surrounding environment. Here we establish a computational quantum-classical boundary from the viewpoint of classical simulatability of a quantum system under decoherence. Specifically, we consider commuting quantum circuits being subject to decoherence. Or equivalently, we can regard them as measurement-based quantum computation on decohered weighted graph states. To show intractability of classical simulation in the quantum side, we utilize the postselection argument and crucially strengthen it by taking noise effect into account. Classical simulatability in the classical side is also shown constructively by using both separable criteria in a projected-entangled-pair-state picture and the Gottesman-Knill theorem for mixed state Clifford circuits. We found that when each qubit is subject to a single-qubit complete-positive-trace-preserving noise, the computational quantum-classical boundary is sharply given by the noise rate required for the distillability of a magic state. The obtained quantum-classical boundary of noisy quantum dynamics reveals a complexity landscape of controlled quantum systems. This paves a way to an experimentally feasible verification of quantum mechanics in a high complexity limit beyond classically simulatable region.
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.
Commuting quantum circuits and complexity of Ising partition functions
NASA Astrophysics Data System (ADS)
Fujii, Keisuke; Morimae, Tomoyuki
2017-03-01
Instantaneous quantum polynomial-time (IQP) computation is a class of quantum computation consisting only of commuting two-qubit gates and is not universal. Nevertheless, it has been shown that if there is a classical algorithm that can simulate IQP efficiently, the polynomial hierarchy collapses to the third level, which is highly implausible. However, the origin of the classical intractability is still less understood. Here we establish a relationship between IQP and computational complexity of calculating the imaginary-valued partition functions of Ising models. We apply the established relationship in two opposite directions. One direction is to find subclasses of IQP that are classically efficiently simulatable by using exact solvability of certain types of Ising models. Another direction is applying quantum computational complexity of IQP to investigate (im)possibility of efficient classical approximations of Ising partition functions with imaginary coupling constants. Specifically, we show that a multiplicative approximation of Ising partition functions is #P-hard for almost all imaginary coupling constants even on planar lattices of a bounded degree.
Fast Katz and commuters : efficient estimation of social relatedness.
On, Byung-Won; Lakshmanan, Laks V. S.; Esfandiar, Pooya; Bonchi, Francesco; Grief, Chen; Gleich, David F.
2010-12-01
Motivated by social network data mining problems such as link prediction and collaborative filtering, significant research effort has been devoted to computing topological measures including the Katz score and the commute time. Existing approaches typically approximate all pairwise relationships simultaneously. In this paper, we are interested in computing: the score for a single pair of nodes, and the top-k nodes with the best scores from a given source node. For the pairwise problem, we apply an iterative algorithm that computes upper and lower bounds for the measures we seek. This algorithm exploits a relationship between the Lanczos process and a quadrature rule. For the top-k problem, we propose an algorithm that only accesses a small portion of the graph and is related to techniques used in personalized PageRank computing. To test the scalability and accuracy of our algorithms we experiment with three real-world networks and find that these algorithms run in milliseconds to seconds without any preprocessing.
A lightweight electronically commutated dc motor for electric passenger vehicles
NASA Astrophysics Data System (ADS)
Echolds, E. F.; Walla, P. S.
1982-09-01
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.
Factors associated with active commuting to work among women.
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.
On spaces of commuting elements in Lie groups
NASA Astrophysics Data System (ADS)
Cohen, Frederick R.; Stafa, Mentor
2016-11-01
The main purpose of this paper is to introduce a method to stabilize certain spaces of homomorphisms from finitely generated free abelian groups to a Lie group $G$, namely $Hom(\\mathbb Z^n,G)$. We show that this stabilized space of homomorphisms decomposes after suspending once with summands which can be reassembled, in a sense to be made precise below, into the individual spaces $Hom(\\mathbb Z^n,G)$ after suspending once. To prove this decomposition, a stable decomposition of an equivariant function space is also developed. One main result is that the topological space of all commuting elements in a compact Lie group is homotopy equivalent to an equivariant function space after inverting the order of the Weyl group. In addition, the homology of the stabilized space admits a very simple description in terms of the tensor algebra generated by the reduced homology of a maximal torus in favorable cases. The stabilized space also allows the description of the additive reduced homology of the individual spaces $Hom(\\mathbb Z^n,G)$, with the order of the Weyl group inverted.
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.
2011-01-01
Background Route environments can positively influence people's active commuting and thereby contribute to public health. The Active Commuting Route Environment Scale (ACRES) was developed to study active commuters' perceptions of their route environments. However, bicycle commuters represent a small portion of the population in many cities and thus are difficult to study using population-based material. Therefore, the aim of this study is to expand the state of knowledge concerning the criterion-related validity of the ACRES and the representativity using an advertisement-recruited sample. Furthermore, by comparing commuting route environment profiles of inner urban and suburban areas, we provide a novel basis for understanding the relationship between environment and bikeability. Methods Bicycle commuters from Greater Stockholm, Sweden, advertisement- (n = 1379) and street-recruited (n = 93), responded to the ACRES. Traffic planning and environmental experts from the Municipality of Stockholm (n = 24) responded to a modified version of the ACRES. The criterion-related validity assessments were based on whether or not differences between the inner urban and the suburban route environments, as indicated by the experts and by four existing objective measurements, were reflected by differences in perceptions of these environments. Comparisons of ratings between advertisement- and street-recruited participants were used for the assessments of representativity. Finally, ratings of inner urban and suburban route environments were used to evaluate commuting route environment profiles. Results Differences in ratings of the inner urban and suburban route environments by the advertisement-recruited participants were in accord with the existing objective measurements and corresponded reasonably well with those of the experts. Overall, there was a reasonably good correspondence between the advertisement- and street-recruited participants' ratings. Distinct differences in
Wahlgren, Lina; Schantz, Peter
2011-01-17
Route environments can positively influence people's active commuting and thereby contribute to public health. The Active Commuting Route Environment Scale (ACRES) was developed to study active commuters' perceptions of their route environments. However, bicycle commuters represent a small portion of the population in many cities and thus are difficult to study using population-based material. Therefore, the aim of this study is to expand the state of knowledge concerning the criterion-related validity of the ACRES and the representativity using an advertisement-recruited sample. Furthermore, by comparing commuting route environment profiles of inner urban and suburban areas, we provide a novel basis for understanding the relationship between environment and bikeability. Bicycle commuters from Greater Stockholm, Sweden, advertisement- (n = 1379) and street-recruited (n = 93), responded to the ACRES. Traffic planning and environmental experts from the Municipality of Stockholm (n = 24) responded to a modified version of the ACRES. The criterion-related validity assessments were based on whether or not differences between the inner urban and the suburban route environments, as indicated by the experts and by four existing objective measurements, were reflected by differences in perceptions of these environments. Comparisons of ratings between advertisement- and street-recruited participants were used for the assessments of representativity. Finally, ratings of inner urban and suburban route environments were used to evaluate commuting route environment profiles. Differences in ratings of the inner urban and suburban route environments by the advertisement-recruited participants were in accord with the existing objective measurements and corresponded reasonably well with those of the experts. Overall, there was a reasonably good correspondence between the advertisement- and street-recruited participants' ratings. Distinct differences in commuting route environment
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.
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.
Shahbazian, M. D.; Valsamakis, A.; Boonyaratanakornkit, J.; Cook, L.; Pang, X. L.; Preiksaitis, J. K.; Schönbrunner, E. R.; Caliendo, A. M.
2013-01-01
Commutability of quantitative reference materials has proven important for reliable and accurate results in clinical chemistry. As international reference standards and commercially produced calibration material have become available to address the variability of viral load assays, the degree to which such materials are commutable and the effect of commutability on assay concordance have been questioned. To investigate this, 60 archived clinical plasma samples, which previously tested positive for cytomegalovirus (CMV), were retested by five different laboratories, each using a different quantitative CMV PCR assay. Results from each laboratory were calibrated both with lab-specific quantitative CMV standards (“lab standards”) and with common, commercially available standards (“CMV panel”). Pairwise analyses among laboratories were performed using mean results from each clinical sample, calibrated first with lab standards and then with the CMV panel. Commutability of the CMV panel was determined based on difference plots for each laboratory pair showing plotted values of standards that were within the 95% prediction intervals for the clinical specimens. Commutability was demonstrated for 6 of 10 laboratory pairs using the CMV panel. In half of these pairs, use of the CMV panel improved quantitative agreement compared to use of lab standards. Two of four laboratory pairs for which the CMV panel was noncommutable showed reduced quantitative agreement when that panel was used as a common calibrator. Commutability of calibration material varies across different quantitative PCR methods. Use of a common, commutable quantitative standard can improve agreement across different assays; use of a noncommutable calibrator can reduce agreement among laboratories. PMID:24025907
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
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.
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.
Commutability of Possible External Quality Assessment Materials for Cardiac Troponin Measurement
Zhang, Shunli; Zeng, Jie; Zhang, Chuanbao; Li, Yilong; Zhao, Haijian; Cheng, Fei; Yu, Songlin; Wang, Mo; Chen, Wenxiang
2014-01-01
Background The measurement of cardiac troponin is crucial in the diagnosis of myocardial infarction. The performance of troponin measurement is most conveniently monitored by external quality assessment (EQA) programs. The commutability of EQA samples is often unknown and the effectiveness of EQA programs is limited. Methods Commutability of possible EQA materials was evaluated. Commercial control materials used in an EQA program, human serum pools prepared from patient samples, purified analyte preparations, swine sera from model animals and a set of patient samples were measured for cTnI with 4 assays including Abbott Architect, Beckman Access, Ortho Vitros and Siemens Centaur. The measurement results were logarithm-transformed, and the transformed data for patient samples were pairwise analyzed with Deming regression and 95% prediction intervals were calculated for each pair of assays. The commutability of the materials was evaluated by comparing the logarithmic results of the materials with the limits of the intervals. Matrix-related biases were estimated for noncommutable materials. The impact of matrix-related bias on EQA was analyzed and a possible correction for the bias was proposed. Results Human serum pools were commutable for all assays; purified analyte preparations were commutable for 2 of the 6 assay pairs; commercial control materials and swine sera were all noncommutable; swine sera showed no reactivity to Vitros assay. The matrix-related biases for noncommutable materials ranged from −83% to 944%. Matrix-related biases of the EQA materials caused major abnormal between-assay variations in the EQA program and correction of the biases normalized the variations. Conclusion Commutability of materials has major impact on the effectiveness of EQA programs for cTnI measurement. Human serum pools prepared from patient samples are commutable and other materials are mostly noncommutable. EQA programs should include at least one human serum pool to allow
Mirabelli, Maria C; Golan, Rachel; Greenwald, Roby; Raysoni, Amit U; Holguin, Fernando; Kewada, Priya; Winquist, Andrea; Flanders, W Dana; Sarnat, Jeremy A
2015-07-01
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. 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. 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]). Level of asthma control may influence respiratory response to in-vehicle exposures experienced during rush-hour commuting.
Demands of Simulated Commuting Using an Electrically Assisted Bicycle.
LA Salle, D Taylor; Shute, Robert; Heesch, Matthew; Slivka, Dustin
2017-01-01
The American College of Sports Medicine (ACSM) recommends adults participate in weekly aerobic activity for a minimum of 30 minutes moderate intensity exercise 5 days per week or 20 minutes of vigorous activity 3 days per week. The electrically assisted bicycle may help individuals achieve the ACSM's aerobic recommendations and introduce inactive individuals to physical activity. To compare the physiological requirements of riding a bicycle with electric pedal assist versus non-assist among healthy active young adults. 6 males and 6 females completed two randomized cycling trials using electric pedal assist (PAB) and non-assist (NON). Cycling trials were completed over a 3.54 km course with varying terrain. Time to completion was faster in the PAB (12.5 ± 0.3 min) than the NON (13.8 ± 0.3 min, p=0.01). Rating of Perceived Exertion (RPE) was lower in the PAB (12.0 ± 0.4) than the NON (14.8 ± 0.5, p < 0.001). There was no difference in mean VO2 between PAB (2.3 ± 0.1 L·min(-1)) and NON (2.5 ± 0.1 L·min(-1), p=0.45). There was no difference in mean power output when comparing PAB (115 ± 11 Watts) to NON (128 ± 11 Watts, p=0.38). There was no difference in heart rate between PAB (147 ± 5 bpm) and NON (149 ± 5 bpm, p=0.77). Recreationally active younger (college age) individuals may self-select a similar physiological intensity of physical activity regardless of mechanical assistance, resulting in quicker completion of a commuting task with PAB. Both the PAB and NON exercise bouts met ACSM criteria for vigorous exercise.
Demands of Simulated Commuting Using an Electrically Assisted Bicycle
LA SALLE, D. TAYLOR; SHUTE, ROBERT; HEESCH, MATTHEW; SLIVKA, DUSTIN
2017-01-01
The American College of Sports Medicine (ACSM) recommends adults participate in weekly aerobic activity for a minimum of 30 minutes moderate intensity exercise 5 days per week or 20 minutes of vigorous activity 3 days per week. The electrically assisted bicycle may help individuals achieve the ACSM’s aerobic recommendations and introduce inactive individuals to physical activity. To compare the physiological requirements of riding a bicycle with electric pedal assist versus non-assist among healthy active young adults. 6 males and 6 females completed two randomized cycling trials using electric pedal assist (PAB) and non-assist (NON). Cycling trials were completed over a 3.54 km course with varying terrain. Time to completion was faster in the PAB (12.5 ± 0.3 min) than the NON (13.8 ± 0.3 min, p=0.01). Rating of Perceived Exertion (RPE) was lower in the PAB (12.0 ± 0.4) than the NON (14.8 ± 0.5, p < 0.001). There was no difference in mean VO2 between PAB (2.3 ± 0.1 L·min−1) and NON (2.5 ± 0.1 L·min−1, p=0.45). There was no difference in mean power output when comparing PAB (115 ± 11 Watts) to NON (128 ± 11 Watts, p=0.38). There was no difference in heart rate between PAB (147 ± 5 bpm) and NON (149 ± 5 bpm, p=0.77). Recreationally active younger (college age) individuals may self-select a similar physiological intensity of physical activity regardless of mechanical assistance, resulting in quicker completion of a commuting task with PAB. Both the PAB and NON exercise bouts met ACSM criteria for vigorous exercise. PMID:28515841
Sociodemographic and environmental correlates of active commuting in rural America.
Fan, Jessie X; Wen, Ming; Kowaleski-Jones, Lori
2015-01-01
This research investigated participation rates in 3 modes of active commuting (AC) and their sociodemographic and physical environmental correlates in rural America. The 2000 Census supplemented with other data sets were used to analyze AC rates in percentage of workers walking, biking, and taking public transportation to work in 14,209 nonmetropolitan rural tracts identified by RUCA codes, including 4,067 small rural and 10,142 town-micropolitan rural tracts. Sociodemographic and physical environmental variables were correlated with 3 AC modes simultaneously using Seemingly Unrelated Regression for nonmetro rural, and for small rural and town-micropolitan rural separately. The average AC rates in rural tracts were 3.63%, 0.26%, and 0.56% for walking, biking, and public transportation to work, respectively, with small rural tracts having a higher rate of walking but lower rates of biking and public transportation to work than town-micropolitan tracts. In general, better economic well-being was negatively associated with AC but percentage of college-educated was a positive correlate. Population density was positively associated with AC but greenness and proximity to parks were negative correlates. However, significant differences existed for different AC modes, and between small rural and town-micropolitan rural tracts. Sociodemographic factors explained more variance in AC than physical environmental factors but the detailed relationships were complex, varying by AC mode and by degree of rurality. Any strategy to promote AC in rural America needs to be sensitive to the population size of the area and assessed in a comprehensive manner to avoid a "one size fits all" approach. © 2014 National Rural Health Association.
Pilot age and geographic region of commuter and air taxi crashes: a case-control study.
Rebok, George W; Qiang, Yandong; Baker, Susan P; Li, Guohua
2011-02-01
Previous studies of major airline and general aviation crashes have identified a host of risk factors. We examined risk factors related to crashes involving commuter air carrier and air taxi flights. A matched case-control design was applied to assess the association of pilot age, total flight time, and geographic region with commuter air carrier and air taxi crashes (14 CFR Part 135) from 1983-2002 in the United States. A total of 2033 commuter air carrier or air taxi crashes from the National Transportation Safety Board aviation crash database were identified as eligible cases. Controls were randomly selected incidents from the Federal Aviation Administration's (FAA) aviation incident database coded under Part 135 operation. Relative to controls, commuter air carrier and air taxi crashes were less likely to occur in pilots under 30 yr of age (adjusted odds ratio 0.68, 95% confidence interval 0.54-0.88) after adjusting for geographic region and total flight time. With adjustment for pilot age and total flight time, the commuter air carrier and air taxi crashes with pilot error were nearly 13 times as likely to be in Alaska as their matched controls (adjusted odds ratio 12.84, 95% confidence interval 5.24-31.45). These results suggest that pilot age may be associated with risk of crash involvement in Part 135 operations. The excess crash risk in Alaska with or without pilot error underscores the importance of environmental hazards in flight safety.
Sandia bicycle commuters group -- pollution prevention at Sandia National Laboratories, New Mexico
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.
Children who commute to school unaccompanied have greater autonomy and perceptions of safety.
Herrador-Colmenero, Manuel; Villa-González, Emilio; Chillón, Palma
2017-08-29
We explored the rates of children who actively commuted to school, both accompanied and unaccompanied, and identified their safety perceptions. This cross-sectional study focused on 745 children, aged 6-12 years, from public schools in the Spanish Granada region. They completed a questionnaire, providing personal data, their school grade, safety perceptions, whether they were accompanied to school and how they travelled to school. We analysed how active commuters were accompanied to school by age group and assessed the associations between safety perceptions and whether or not they were accompanied. Children aged 10-12 years were more likely to travel to school unaccompanied, more likely to travel actively and had better safety perceptions than younger children. We also found differences in how active commuters between 10 and 12 years and children aged 6-7 and 8-9 years (all p < 0.001) were accompanied to school. Children aged 10-12 years who actively commuted unaccompanied had a better understanding of safety issues than accompanied children (p < 0.010). Older children who actively commuted to school unaccompanied had better safety perceptions than other children in this sample of children aged 6-12. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.
Mendoza, Jason A; Watson, Kathy; Baranowski, Tom; Nicklas, Theresa A; Uscanga, Doris K; Nguyen, Nga; Hanfling, Marcus J
2010-09-30
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
Almost commuting self-adjoint matrices: The real and self-dual cases
NASA Astrophysics Data System (ADS)
Loring, Terry A.; Sørensen, Adam P. W.
2016-08-01
We show that a pair of almost commuting self-adjoint, symmetric matrices is close to a pair of commuting self-adjoint, symmetric matrices (in a uniform way). Moreover, we prove that the same holds with self-dual in place of symmetric and also for paths of self-adjoint matrices. Since a symmetric, self-adjoint matrix is real, we get a real version of Huaxin Lin’s famous theorem on almost commuting matrices. Similarly, the self-dual case gives a version for matrices over the quaternions. To prove these results, we develop a theory of semiprojectivity for real C*-algebras and also examine various definitions of low-rank for real C*-algebras.
Suicides in commuting railway systems: The case of Stockholm county, Sweden.
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.
Commuting to work: RN travel time to employment in rural and urban areas.
Rosenberg, Marie-Claire; Corcoran, Sean P; Kovner, Christine; Brewer, Carol
2011-02-01
To investigate the variation in average daily travel time to work among registered nurses (RNs) living in urban, suburban, and rural areas. We examine how travel time varies across RN characteristics, job setting, and availability of local employment opportunities. Descriptive statistics and linear regression using a 5% sample from the 2000 Census and a longitudinal survey of newly licensed RNs (NLRN). Travel time for NLRN respondents was estimated using geographic information systems (GIS) software. In the NLRN, rural nurses and those living in small towns had significantly longer average commute times. Young married RNs and RNs with children also tended to have longer commute times, as did RNs employed by hospitals. The findings indicate that travel time to work varies significantly across locale types. Further research is needed to understand whether and to what extent lengthy commute times impact RN workforce needs in rural and urban areas.
Duality and gauge invariance of non-commutative spacetime Podolsky electromagnetic theory
NASA Astrophysics Data System (ADS)
Abreu, Everton M. C.; Fernandes, Rafael L.; Mendes, Albert C. R.; Neto, Jorge Ananias; Neves, Mario, Jr.
2017-01-01
The interest in higher derivative field theories has its origin mainly in their influence concerning the renormalization properties of physical models and to remove ultraviolet divergences. In this paper, we have introduced the non-commutative (NC) version of the Podolsky theory and we investigated the effect of the non-commutativity over its original gauge invariance property. We have demonstrated precisely that the non-commutativity spoiled the primary gauge invariance of the original action under this primary gauge transformation. After that we have used the Noether dualization technique to obtain a dual and gauge invariant action. We have demonstrated that through the introduction of a Stueckelberg field in this NC model, we can also recover the primary gauge invariance. In this way, we have accomplished a comparison between both methods.
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.
Late time acceleration in a non-commutative model of modified cosmology
NASA Astrophysics Data System (ADS)
Malekolkalami, B.; Atazadeh, K.; Vakili, B.
2014-12-01
We investigate the effects of non-commutativity between the position-position, position-momentum and momentum-momentum of a phase space corresponding to a modified cosmological model. We show that the existence of such non-commutativity results in a Moyal Poisson algebra between the phase space variables in which the product law between the functions is of the kind of an α-deformed product. We then transform the variables in such a way that the Poisson brackets between the dynamical variables take the form of a usual Poisson bracket but this time with a noncommutative structure. For a power law expression for the function of the Ricci scalar with which the action of the gravity model is modified, the exact solutions in the commutative and noncommutative cases are presented and compared. In terms of these solutions we address the issue of the late time acceleration in cosmic evolution.
Zuurbier, Moniek; Hoek, Gerard; Oldenwening, Marieke; Lenters, Virissa; Meliefste, Kees; van den Hazel, Peter; Brunekreef, Bert
2010-06-01
Commuters are exposed to high concentrations of air pollutants, but little quantitative information is currently available on differences in exposure between different modes of transport, routes, and fuel types. The aim of our study was to assess differences in commuters' exposure to traffic-related air pollution related to transport mode, route, and fuel type. We measured particle number counts (PNCs) and concentrations of PM2.5 (particulate matter
Baral, Randolph M; Dhand, Navneet K; Freeman, Kathleen P
2016-06-01
Species-specific plasma or serum pools are considered the ideal standard material for quality control materials (QCM) instead of commercially available human QCM. However, using plasma or serum pools is limited by volume restrictions, degradation over time, and a narrow range of analyte concentrations. Concentrations of QCM analytes should be consistent or commutable with those from species-specific plasma/serum samples, and the precision from plasma pools should be comparable or interchangeable with commercial human QCM. The aims of this study were to determine the commutability and interchangeability of 2 levels of commercial QCM (MAS chemTRAK-H [CT]) with feline plasma pools (PP) from normal and renal disease cats measured using a commercial laboratory analyzer and a veterinary in-house analyzer. Agreement between the 2 analyzers was assessed for 16 analytes by correlation and Passing-Bablok regression analyses of feline plasma samples. The difference between each CT data point and the regression line (residuals) was determined and standardized, and CT were considered 'commutable' with PP if the standardized residual was within a range of -3 to 3. Coefficients of variation (CVs) for CT and PP for 16 analytes on 2 analyzers were compared by bootstrap analysis to determine interchangeability. Most CT analytes were within the range of patient plasma sample analytes, thus commutable. Only 2 analytes had equivalent precision for both levels of CT and both levels of PP, and 5 additional analytes had similar precision for at least one level of CT compared to at least one level of PP. The QCM assessed is commutable to feline PP within the tested ranges for 2 particular analyzers. Commutability does not grant interchangeability. © 2016 American Society for Veterinary Clinical Pathology.
The commuters' exposure to volatile chemicals and carcinogenic risk in Mexico City
NASA Astrophysics Data System (ADS)
Shiohara, Naohide; Fernández-Bremauntz, Adrián A.; Blanco Jiménez, Salvador; Yanagisawa, Yukio
The commuters' exposure levels to volatile organic compounds were investigated in the following public transport modes: private car, microbus, bus, and metro along three commuting routes in the Metropolitan Area of Mexico City. The target chemicals were benzene, toluene, ethylbenzene, m/ p-xylene, and formaldehyde. Integrated samples were taken while traveling during the morning rush hour (weekdays 7:00-9:00 a.m.) for six consecutive weeks in June and July, 2002. Scheffe test showed that the average concentrations of all chemicals inside cars and microbuses were statistically higher than in metro trains ( P<0.05). For non-formaldehyde chemicals, the average levels inside automobiles were significantly higher than in metro trains and buses ( P<0.05). The exposure level of formaldehyde in the microbus was much higher than those in the car, bus, and metro ( P<0.05). On the other hand, there were no differences in the exposure levels among transport routes. These findings suggest that for commuting trips of comparable durations, car and microbus passengers are exposed to higher levels of volatile organic compounds than bus and metro commuters. These findings are consistent with previous studies looking at exposure of commuters to carbon monoxide. The lifetime carcinogenic risk from commuting by car was 2.0×10 -5-3.1×10 -5, that by microbus was 3.1×10 -5-4.0×10 -5, that by bus was 2.0×10 -5-2.7×10 -5, and that by metro was 1.3×10 -5-1.7×10 -5 in Mexico City.
2012-01-01
Background Promoting walking or cycling to work (active commuting) could help to increase population physical activity levels. According to the habit discontinuity and residential self-selection hypotheses, moving home or workplace is a period when people (re)assess, and may be more likely to change, their travel behavior. Research in this area is dominated by the use of quantitative research methods, but qualitative approaches can provide in-depth insight into the experiences and processes of travel behavior change. This qualitative study aimed to explore experiences and motivations regarding travel behavior around the period of relocation, in an effort to understand how active commuting might be promoted more effectively. Methods Participants were recruited from the Commuting and Health in Cambridge study cohort in the UK. Commuters who had moved home, workplace or both between 2009 and 2010 were identified, and a purposive sample was invited to participate in semi-structured interviews regarding their experiences of, and travel behavior before and after, relocating. A grounded theory approach was taken to analysis. Results Twenty-six commuters participated. Participants were motivated by convenience, speed, cost and reliability when selecting modes of travel for commuting. Physical activity was not a primary motivation, but incidental increases in physical activity were described and valued in association with active commuting, the use of public transport and the use of park-and-ride facilities. Conclusions Emphasizing and improving the relative convenience, cost, speed and reliability of active commuting may be a more promising approach to promoting its uptake than emphasizing the health benefits, at least around the time of relocation. Providing good quality public transport and free car parking within walking or cycling distance of major employment sites may encourage the inclusion of active travel in the journey to work, particularly for people who live too
Relativistic spectrum of hydrogen atom in the space-time non-commutativity
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.
Assessment of different route choice on commuters' exposure to air pollution in Taipei, Taiwan.
Li, Hsien-Chih; Chiueh, Pei-Te; Liu, Shi-Ping; Huang, Yu-Yang
2017-01-01
The purposes of this study are to develop a healthy commute map indicating cleanest route in Taipei metropolitan area for any given journey and to evaluate the pollutant doses exposed in different commuting modes. In Taiwan, there are more than 13.6 million motorcycles and 7.7 million vehicles among the 23 million people. Exposure to traffic-related air pollutants can thus cause adverse health effects. Moreover, increasing the level of physical activity during commuting and longer distances will result in inhalation of more polluted air. In this study, we utilized air pollution monitoring data (CO, SO2, NO2, PM10, and PM2.5) from Taiwan EPA's air quality monitoring stations in Taipei metropolitan area to estimate each pollutant exposure while commuting by different modes (motorcycling, bicycling, and walking). Spatial interpolation methods such as inverse distance weighting (IDW) were used to estimate each pollutant's distribution in Taipei metropolitan area. Three routes were selected to represent the variety of different daily commuting pathways. The cleanest route choice was based upon Dijkstra's algorithm to find the lowest cumulative pollutant exposure. The IDW interpolated values of CO, SO2, NO2, PM10, and PM2.5 ranged from 0.42-2.2 (ppm), 2.6-4.8 (ppb), 17.8-42.9 (ppb), 32.4-65.6 (μg/m(3)), and 14.2-38.9 (μg/m(3)), respectively. To compare with the IDW results, concentration of particulate matter (PM10, PM2.5, and PM1) along the motorcycle route was measured in real time. In conclusion, the results showed that the shortest commuting route for motorcyclists resulted in a much higher cumulative dose (PM2.5 3340.8 μg/m(3)) than the cleanest route (PM2.5 912.5 μg/m(3)). The mobile personal monitoring indicated that the motorcyclists inhaled significant high pollutants during commuting as a result of high-concentration exposure and short-duration peaks. The study could effectively present less polluted commuting routes for citizen health benefits.
On the linearization of nonlinear supersymmetry based on the commutator algebra
NASA Astrophysics Data System (ADS)
Tsuda, Motomu
2017-01-01
We discuss a linearization procedure of nonlinear supersymmetry (NLSUSY) based on the closure of the commutator algebra for variations of functionals of Nambu-Goldstone fermions and their derivative terms under NLSUSY transformations in Volkov-Akulov NLSUSY theory. In the case of a set of bosonic and fermionic functionals, which leads to (massless) vector linear supermultiplets, we explicitly show that general linear SUSY transformations of basic components defined from those functionals are uniquely determined by examining the commutation relation in the NLSUSY theory.
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.
Silicon-controlled-rectifier square-wave inverter with protection against commutation failure
NASA Technical Reports Server (NTRS)
Birchenough, A. G.
1971-01-01
The square-wave SCR inverter that was designed, built, and tested includes a circuit to turn off the inverter in case of commutation failure. The basic power stage is a complementary impulse-commutated parallel inverter consisting of only six components. The 400-watt breadboard was tested while operating at + or - 28 volts, and it had a peak efficiency of 95.5 percent at 60 hertz and 91.7 percent at 400 hertz. The voltage regulation for a fixed input was 3 percent at 60 hertz. An analysis of the operation and design information is included.
Radiative corrections to the non commutative photon propagator at one-loop order
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.
Code of Federal Regulations, 2011 CFR
2011-10-01
... of train employees engaged in commuter or intercity rail passenger transportation. (a) General... require or allow a train employee engaged in commuter or intercity rail passenger transportation to remain... 49 Transportation 4 2011-10-01 2011-10-01 false Limitations on duty hours of train...
76 FR 65769 - Application of Friendship Airways, Inc. d/b/a Yellow Air Taxi for Commuter Authority
Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-24
... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Friendship Airways, Inc. d/b/a Yellow Air Taxi for Commuter... to show cause why it should revoke the Commuter Air Carrier Authorization issued to Friendship...
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 1 2011-10-01 2011-10-01 false Remanufacture of intercity and commuter rail cars and purchase or lease of remanufactured intercity and commuter rail cars. 37.89 Section 37.89 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Acquisition of Accessible Vehicles...
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 1 2010-10-01 2010-10-01 false Remanufacture of intercity and commuter rail cars and purchase or lease of remanufactured intercity and commuter rail cars. 37.89 Section 37.89 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Acquisition of Accessible Vehicles...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-08
... 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 Air International fit, willing, and able, and awarding it Commuter Air Carrier Authorization. DATES: Persons...
Cui, Zhaohui; Bauman, Adrian; Dibley, Michael J.
2011-01-01
Objective To examine trends and correlates of passive (inactive) commuting to school among Chinese children aged 6–18 years in nine provinces. Methods The trends analysis used school commuting data from the China Health and Nutrition Surveys in 1997 (n=2454), 2000 (n=1978), 2004 (n=1549) and 2006 (n=1236). Generalised estimating equations examined trends after adjusting for age, sex and region, and also explored the correlates of passive commuting to school in urban and rural areas (n=6935). Results An increase in passive commuting to school was noted (3.6% in 1997, 14.1% in 2006, P < 0.0001). Children attending schools not located in their local community were more likely to passively commute. In urban areas, maternal education was associated with increased passive commuting (AOR = 1.41, 95%CI: 1.03–1.92). In rural areas, family income (AOR high/low = 2.12, 95%CI: 1.52–2.96), paternal education (AOR high/low = 1.56, 95%CI: 1.17 – 2.07), motorcycle ownership (AOR = 1.57, 95%CI: 1.19–2.07) were associated with passive commuting. Conclusion Passive commuting to school increased in China over a decade and was associated with family socioeconomic status, school location, and in rural children, with access to motorised vehicles. PMID:21524662
High Power, Repetitive, Stacked Blumlein Pulse Generators Commuted by a Single Switching Element
NASA Astrophysics Data System (ADS)
Bhawalkar, Jayant Dilip
In this work, the stacked Blumlein pulsers developed at the University of Texas at Dallas were characterized and shown to be versatile sources of pulse power for a variety of applications. These devices consisted of several triaxial Blumleins stacked in series at one end. The lines were charged in parallel and synchronously commuted repetitively with a single switching element at the other end. In this way, relatively low charging voltages were multiplied to give a high discharge voltage across an arbitrary load without the need for complex Marx bank circuitry. Several pulser parameters such as the number of stacked Blumlein lines, line configuration, type of switching element, and the length of the lines, were varied and the waveform characteristics were observed and analyzed. It was shown that these devices are capable of generating fast rising waveforms with a wide range of peak voltage and current values. The generation of high power waveforms with pulse durations in the range of 80-600 ns was demonstrated without degradation of the voltage gains. The results of this work indicated that unlike generators based on stacked transmission lines, the effects of parasitic modes were not appreciable for the stacked Blumlein pulsers. Opportunities for tactically packaging these pulsers were also investigated and a significant reduction in their size and weight was demonstrated. For this, dielectric lifetime and Blumlein spacing studies were performed on small scale prototypes. In addition to production of intense X-ray pulses, the possible applications for these novel pulsers include driving magnetrons for high power microwave generation, pumping laser media, or powering e-beam diodes. They could also serve as compact, tabletop sources of high power pulses for various research experiments.
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…
40 CFR 52.1134 - Regulation limiting on-street parking by commuters.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Regulation limiting on-street parking...) Massachusetts § 52.1134 Regulation limiting on-street parking by commuters. (a) On-street parking means parking a motor vehicle on any street, highway, or roadway, except for legal stops within designated loading...
40 CFR 52.1134 - Regulation limiting on-street parking by commuters.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Regulation limiting on-street parking...) Massachusetts § 52.1134 Regulation limiting on-street parking by commuters. (a) On-street parking means parking a motor vehicle on any street, highway, or roadway, except for legal stops within designated loading...
40 CFR 52.1134 - Regulation limiting on-street parking by commuters.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Regulation limiting on-street parking...) Massachusetts § 52.1134 Regulation limiting on-street parking by commuters. (a) On-street parking means parking a motor vehicle on any street, highway, or roadway, except for legal stops within designated loading...
40 CFR 52.1134 - Regulation limiting on-street parking by commuters.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Regulation limiting on-street parking...) Massachusetts § 52.1134 Regulation limiting on-street parking by commuters. (a) On-street parking means parking a motor vehicle on any street, highway, or roadway, except for legal stops within designated loading...
ERIC Educational Resources Information Center
Dwyer, Tomás
2017-01-01
Student-faculty interactions are a component of social integration, a key concept in Tinto's theory of student persistence which has received empirical support. However, the influence of social integration for commuting students has been questioned. Furthermore, student-faculty interactions in the classroom are under-researched and arguably…
Serving Commuter Students: Examples of Good Practice. 4th Edition-1993.
ERIC Educational Resources Information Center
Hamcke, Adrienne J., Ed.
This document is a compendium of descriptions of 163 innovative programs and services for commuter college and university students from campuses across the nation. Entries include a brief description of the program, statement of goals, rationale, and pertinent background information; resources including staff, volunteer, and funding; evaluation…
The Mental Health of Commuter College Students: A Partial Test of Kysar's Hypothesis.
ERIC Educational Resources Information Center
Bown, Oliver H.; Richek, Herbert G.
Proceding from the hypothesis of J. E. Kysar to the effect that college commuter students have poorer "mental health" than their age-mates residing in colleges geographically removed from their homes, the Bown Self-Report Inventory (SRI) scores of 1265 males and 899 females attending the University of Texas at Austin were compared. In…
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...
49 CFR 37.87 - Purchase or lease of used intercity and commuter rail cars.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 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...
Patterns and Determinants of Student Affiliation at a Public Urban Commuter College. Final Report.
ERIC Educational Resources Information Center
Bolton, Charles D.; And Others
The report covers preparatory work for a further two-year study of student affiliation and drop-out at a four-year urban commuter college, Portland State College. The principal task was the development and testing of a series of scales measuring various aspects of student affiliation. After preliminary testing, scale test items were administered…
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…
Environmental justice in the context of commuters' exposure to CO and PM10 in Bangalore, India.
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.
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…
Non-commutative geometry in higher dimensional quantum hall effect as A-class topological insulator
NASA Astrophysics Data System (ADS)
Hasebe, K.
2014-09-01
We clarify relations between the higher dimensional quantum Hall effect and A-class topological insulator. In particular, we elucidate physical implications of the higher dimensional non-commutative geometry in the context of A-class topological insulator. This presentation is based on arXiv:1403.5066.
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…
Ruiz-Ariza, Alberto; de la Torre-Cruz, Manuel J; Redecillas-Peiró, María T; Martínez-López, Emilio J
2015-01-01
To analyse the association between active commuting to secondary school and indicators of psychological health in a sample of 1012 adolescents. Active commuting was assessed through a questionnaire, subjective happiness with the Subjective Happiness Scale, well-being and psychological distress with the General Well-Being Scale, and body shape was assessed using the short version of the Body Shape Questionnaire. Adolescents who spent more than 15 minutes per day actively commuting to secondary school had higher levels of subjective happiness (p=0.032) and psychological well-being (p=0.021) and lower levels of psychological distress (p=0.021) than adolescents who spent 15 minutes or less per day. There were no differences in body shape between less and more active adolescents (p >0.05). Active commuting to secondary school for more of 15 minutes per day is recommended because it is associated with higher levels of happiness and well-being in adolescents. Copyright © 2015 SESPAS. Published by Elsevier Espana. All rights reserved.
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…
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…
NASA Astrophysics Data System (ADS)
Grünbaum, F. A.; Pacharoni, I.; Zurrián, I.
2017-02-01
The problem of recovering a signal of finite duration from a piece of its Fourier transform was solved at Bell Labs in the 1960’s, by exploiting a ‘miracle’: a certain naturally appearing integral operator commutes with an explicit differential one. Here we show that this same miracle holds in a matrix valued version of the same problem.
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…
Charge and/or spin limits for black holes at a non-commutative scale
NASA Astrophysics Data System (ADS)
Paik, Biplab
2017-08-01
In the commutative geometrical background, one finds the total charge ( Q) and/or the total angular momentum ( J) of a generalized black hole of mass M to be bounded by the condition Q^2+( J{/}M) ^2≤ M^2, whereas the inclusion of the concept of non-commutativity in geometry leads to a much more richer result. It predicts that the upper limit to Q and/or J is not fixed but depends on the mass/length scale of black holes; it (the upper limit to Q and/or J) goes towards a `commutative limit' when {M≫ √{θ}} (√{θ} characterizes the minimal length scale) and rapidly diminishes towards zero with M decreasing in the strongly non-commutative regime, until approaching a perfect zero value for {M˜eq 1.904√{θ}}. We have performed separate calculations for a pure Kerr or a pure Reissner-Nordström black hole, and briefly done it for a generalized black hole.
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 §...
Physical activity in the older adults related to commuting and leisure, Maceió, Brazil
Mourão, Ana Raquel de Carvalho; Novais, Francini Vilela; Andreoni, Solange; Ramos, Luiz Roberto
2013-01-01
OBJECTIVE To evaluate the level of physical activity of older adults by commuting and leisure time and associated factors. METHODS This was a cross-sectional study carried out with a population-based sample of 319 older individuals in Maceió, AL, Northeastern Brazil, in 2009. The level of physical activity in leisure and commuting was measured by applying the International Physical Activity Questionnaire, long version. The variables analyzed were: age, schooling, sex, per capita income and perceived health. We used descriptive analysis, Fisher's exact test and multiple regression analysis of prevalence rates. RESULTS We classified 87.5% as insufficiently active in commuting, being significantly higher among those individuals with older ages, with more education and who feel dissatisfied with their physical health. The prevalence of older people who are insufficiently active in leisure time activity was 76.2%, being more frequent in women, in men with advanced age; older adults with lower per capita income, and dissatisfaction with comparative physical health and self-perceived mental health. CONCLUSIONS The prevalence of insufficiently active was high in commuting and leisure time activities. Factors such as age, gender and income should be considered, especially with regards leisure, in order to ensure fairness in the development of policies to promote health and physical activity in this population. PMID:24626549
Miller, W Greg
2003-01-01
The objective of external quality assessment is to evaluate clinical acceptability of laboratory results. It is desirable to evaluate intermethod harmonization and traceability to a reference system. Conventional matrix-modified processed materials are used in most programs, because they can be produced in large quantities, can have multiple abnormal analytes in the same vial and have excellent stability. The principal limitation of these materials is non-commutability which makes them unsuitable for traceability or harmonization evaluation. Peer group evaluation is used which allows an individual laboratory to confirm appropriate use of a measurement technology and a manufacturer to monitor uniformity in their calibration transfer process. Authentic clinical specimen pools provide commutability but are limited by the quantity available and number of analytes at pathologic levels in the same vial. Hybrid approaches have used authentic clinical specimen pools in conjunction with non-commutable processed materials to determine method-specific matrix-corrected target values which have enabled evaluation of traceability to reference methods. Conventional processed materials are limited by non-commutability. Pooled clinical specimens are limited by availability. When used together, external quality assessment can evaluate traceability to reference systems and harmonization between test procedures.
USDA-ARS?s Scientific Manuscript database
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...
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 as...
Social Involvement and Commuter Students: The First-Year Student Voice
ERIC Educational Resources Information Center
Krause, Kerri-Lee D.
2007-01-01
This qualitative study explores the nature of undergraduate commuter students' social involvement with peers during the transitional first six months of their university experience. Focus group interviews with 46 participants provided a student perspective of the role of social interactions in students' transition to university life. Findings…
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…
A Model for Promoting Student Interaction on Community College (Commuter) Campuses.
ERIC Educational Resources Information Center
Ridge, Richard A.
The planning and development of a program to promote interaction among commuter students at Germanna Community College and to provide for their various needs are described. The program involved establishing an Interaction Center (IC) in 1974, centrally located in proximity to the college's learning resources center and library. The center was to…
Effects of a culturally sensitive sign on the use of stairs in African American commuters.
Andersen, Ross E; Franckowiak, Shawn C; Zuzak, Kim B; Cummings, Elise S; Bartlett, Susan J; Crespo, Carlos J
2006-01-01
To examine the effectiveness of a culturally sensitive sign to encourage stair use among African American commuters. 16,035 commuters were observed in their using either stairs or an adjacent escalator in a subway station. After baseline observation, a culturally sensitive sign to promote stair use was displayed beside the escalator/stairs. Demographic information and use of escalators/stairs were recorded. Stair use increased from 15.8% to 21.5% with the sign. Caucasian commuters used the stairs 23.1% of the time at baseline, and increased to 28.3% with the sign. Among African Americans, stair use increased from 10.3% to 16.4% with the sign. African American women showed the greatest increases in stair use. Stair use remained elevated the week after the sign was removed in all commuters. Among African Americans, stair use returned to baseline within three weeks. Stair use increased significantly among both overweight and non-overweight Caucasians and African Americans. Culturally sensitive interventions can promote physical activity among African Americans in an urban setting.
20 CFR 702.142 - Commutation of payments; aliens not residents or about to become nonresidents.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false Commutation of payments; aliens not residents or about to become nonresidents. 702.142 Section 702.142 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES ADMINISTRATION AND PROCEDURE...
20 CFR 702.142 - Commutation of payments; aliens not residents or about to become nonresidents.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Commutation of payments; aliens not residents or about to become nonresidents. 702.142 Section 702.142 Employees' Benefits EMPLOYMENT STANDARDS ADMINISTRATION, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES ADMINISTRATION AND PROCEDURE...
20 CFR 702.142 - Commutation of payments; aliens not residents or about to become nonresidents.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false Commutation of payments; aliens not residents or about to become nonresidents. 702.142 Section 702.142 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES ADMINISTRATION AND PROCEDURE...
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…
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…
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…
75 FR 12328 - Application of Charter Air Transport, Inc. for Commuter Authority
Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-15
... 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 AGENCY... it should not issue an order finding Charter Air Transport, Inc., fit, willing, and able,...
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...
Fermionic Tunneling Effect and Hawking Radiation in a Non Commutative FRW Universe
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.
Cycle Commuting and Perceptions of Barriers: Stages of Change, Gender and Occupation
ERIC Educational Resources Information Center
van Bekkum, Jennifer E.; Williams, Joanne M.; Morris, Paul Graham
2011-01-01
Purpose: The aim of this study is to investigate perceptions of cycle commuting barriers in relation to stage of change, gender and occupational role. Stage of change is a key construct of the transtheoretical model of behaviour change that defines behavioural readiness (intentions and actions) into five distinct categories.…
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.
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…
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…
40 CFR 52.1161 - Incentives for reduction in single-passenger commuter vehicle use.
Code of Federal Regulations, 2012 CFR
2012-07-01
... located in the Boston Intrastate Region. (3) Employee means any person who performs work for an employer... travels to and from work by any mode of travel. (4) Student means any full-time day student who does not... employee and a student. (7) Single-passenger commuter vehicle means a motor-driven vehicle with four...
Quantum Brownian Motion on Non-Commutative Manifolds: Construction, Deformation and Exit Times
NASA Astrophysics Data System (ADS)
Das, Biswarup; Goswami, Debashish
2012-01-01
We begin with a review and analytical construction of quantum Gaussian process (and quantum Brownian motions) in the sense of Franz (The Theory of Quantum Levy Processes,