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.
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.
NASA Astrophysics Data System (ADS)
Yang, Fei; Ma, Ruiguang; Wu, Yi; Sun, Hao; Niu, Chunping; Rong, Mingzhe
2012-02-01
This paper focuses on the numerical investigation of arc plasma behavior during arc commutation process in a medium-voltage direct current circuit breaker (DCCB) contact system. A three-dimensional magneto-hydrodynamic (MHD) model of air arc plasma in the contact system of a DCCB is developed, based on commercial software FLUENT. Coupled electromagnetic and gas dynamic interactions are considered as usual, and a thin layer of nonlinear electrical resistance elements is used to represent the voltage drop of plasma sheath and the formation of new arc root. The distributions of pressure, temperature, gas flow and current density of arc plasma in arc region are calculated. The simulation results indicate that the pressure distribution related to the contact system has a strong effect on the arc commutation process, arising from the change of electrical conductivity in the arc root region. In DCCB contact system, the pressure of arc root region will be concentrated and higher if the space above the moving contact is enclosed, which is not good for arc root commutation. However, when the region is opened, the pressure distribution would be lower and more evenly, which is favorable for the arc root commutation.
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. PMID:21626481
Edge currents in non-commutative Chern-Simons theory from a new matrix model
NASA Astrophysics Data System (ADS)
Balachandran, Aiyalam P.; Kürkçüoglu, Seçkin; Gupta, Kumar S.
2003-09-01
This paper discusses the formulation of the non-commutative Chern-Simons (CS) theory where the spatial slice, an infinite strip, is a manifold with boundaries. As standard *-products are not correct for such manifolds, the standard non-commutative CS theory is not also appropriate here. Instead we formulate a new finite-dimensional matrix CS model as an approximation to the CS theory on the strip. A work which has points of contact with ours is due to Lizzi, Vitale and Zampini where the authors obtain a description for the fuzzy disc. The gauge fields in our approach are operators supported on a subspace of finite dimension N+eta of the Hilbert space of eigenstates of a simple harmonic oscillator with N ,etainBbb Z+ and N\
NASA Astrophysics Data System (ADS)
Yim, S.-W.; Park, B.-C.; Jeong, Y.-T.; Kim, Y.-J.; Yang, S.-E.; Kim, W.-S.; Kim, H.-R.; Du, H.-I.
2013-01-01
A 22.9 kV class hybrid fault current limiter (FCL) developed by Korea Electric Power Corporation and LS Industrial Systems in 2006 operates using the line commutation mechanism and begins to limit the fault current after the first half-cycle. The first peak of the fault current is available for protective coordination in the power system. However, it also produces a large electromagnetic force and imposes a huge stress on power facilities such as the main transformer and gas-insulated switchgear. In this study, we improved the operational characteristics of the hybrid FCL in order to reduce the first peak of the fault current. While maintaining the structure of the hybrid FCL system, we developed a superconducting module that detects and limits the fault current during the first half-cycle. To maintain the protective coordination capacity, the hybrid FCL was designed to reduce the first peak value of the fault current by up to approximately 30%. The superconducting module was also designed to produce a minimum AC loss, generating a small, uniform magnetic field distribution during normal operation. Performance tests confirmed that when applied to the hybrid FCL, the superconducting module showed successful current limiting operation without any damage.
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.
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.
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.
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.
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.
NASA Technical Reports Server (NTRS)
Windley, P.
1992-01-01
We present a state property called congruence and show how it can be used to demonstrate commutivity of instructions in a modern load-store architecture. Our analysis is particularly important in pipelined microprocessors where instructions are frequently reordered to avoid costly delays in execution caused by hazards. Our work has significant implications to safety and security critical applications since reordering can easily change the meaning and an instruction sequence and current techniques are largely ad hoc. Our work is done in a mechanical theorem prover and results in a set of trustworthy rules for instruction reordering. The mechanization makes it practical to analyze the entire instruction set.
Künn-Nelen, Annemarie
2016-08-01
This paper analyzes the relation between commuting time and health in the UK. I focus on four different types of health outcomes: subjective health measures, objective health measures, health behavior, and healthcare utilization. Fixed effect models are estimated with British Household Panel Survey data. I find that whereas objective health and health behavior are barely affected by commuting time, subjective health measures are clearly lower for people who commute longer. A longer commuting time is, moreover, related to more visits to the general practitioner. Effects turn out to be more pronounced for women and for commuters driving a car. For women, commuting time is also negatively related to regular exercise and positively to calling in sick. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26010157
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.
Inductively commutated coilguns
NASA Astrophysics Data System (ADS)
Mongeau, Peter P.
1991-01-01
The concept and relevance of power factor is presented in the context of high-performance launchers. As the scale of launchers grows and 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.
Voltage reapplication rate control for commutation of thyristors
NASA Technical Reports Server (NTRS)
Rippel, Wally E. (Inventor); Edwards, Dean B. (Inventor)
1982-01-01
A circuit for commutating a thyristor (21) by shunting its current for a minimum interval, thereby removing sustaining voltage to said thyristor, then subsequently restoring voltage to said thyristor at a predetermined rate, utilizes a series combination of a commutation electronic switch (22) and an isolated dc voltage supply (23) connected in parallel with the thyristor. The voltage supply is arranged with a polarity that permits the current flowing through the thyristor in one direction to be bypassed through the series combination while the commutation switch is turned on and to reverse bias the thyristor when the commutation switch is fully on. A dv/dt control circuit (24) limits the rate of rise of voltage across the commutation switch (22) as it is turned off in response to a command input signal. The dv/dt control circuit is comprised of a constant current drive (31) and a capacitor (32) connected between the output terminal of the commutation switch and the control input terminal of the commutation switch. The thyristor may be a triac (40) with two commutation switches (42, 43), one for current of each polarity, or with a single commutation switch (55) and a bridge circuit (52-55) for selecting the polarity of the switch (56).
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.
NASA Astrophysics Data System (ADS)
Bernard, R.; Glises, R.; Chamagne, D.; Cuchet, D.; Kauffmann, J. M.
1999-08-01
The aim of this work concerns the development and the validation of a thermal steady state model applied to a permanent magnet direct current motor with commutator. The rated power of the machine is 120 W. Design has been realized thanks to the thermal modulus of the computation software with the finite element method Flux3D. It is shown in this work how it is possible to use only the heat equation to simulate the thermal behaviour of the motor. It implies calculating of new fluid conductivities (considering also all thermal modes) by comparison of calculated and experimental temperatures. To realize these 3D modelizations, it is necessary to know and to locate all the losses of the motor which are considered as thermal sources. The experimental temperatures are given by 40 chromel-alumel thermocouples of 100 μm diameter located in the rotor and the stator of the machine. Numerical computations use Dirichlet boundary layer conditions given by an IR camera. Ce travail concerne le développement et la validation d'un modèle de simulation du comportement thermique tridimensionnel en régime permanent d'un moteur électrique de 120 watt à courant continu, à aimants permanents et à collecteur. Le logiciel est développé à partir du code de calculs par éléments finis Flux3D. L'équation de la chaleur modélise l'ensemble des transferts thermiques du moteur. Cela nécessite de recaler certains paramètres fluides par comparaison des températures simulées et expérimentales. Une séparation détaillée des différentes pertes est nécessaire pour obtenir une bonne précision finale. Un banc d'essais thermiques permet d'obtenir à l'aide de 40 thermocouples (chromel-alumel de 100 μm de diamètre) les températures au stator et au rotor. Une caméra thermographique infrarouge donne les conditions aux limites de Dirichlet nécessaires à la modélisation.
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.
Technology Transfer Automated Retrieval System (TEKTRAN)
Declines in physical activity levels have coincided with increasing rates of obesity in children. This is problematic because physical activity has been shown to attenuate weight gain in children. Active commuting to school is one way of increasing children's physical activity. However, given the hi...
ERIC Educational Resources Information Center
Ullman, Ellen
2011-01-01
For the last few years, Georgia State University has taken steps toward becoming a more traditional college instead of a commuter school. It bought two Atlanta hotels to be used as residence halls, started a football team, and is building townhouses for Greek fraternities and sororities. "When alumni come back to campus, they are shocked at all…
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.
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.
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.
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.
Inertial spin Hall effect in non-commutative space
NASA Astrophysics Data System (ADS)
Basu, B.; Chowdhury, Debashree; Ghosh, Subir
2013-10-01
In the present Letter the study of inertial spin current (that appears in an accelerated frame of reference) is extended to Non-Commutative (NC) space. In the Hamiltonian framework, the Dirac Hamiltonian in an accelerating frame is computed in the low energy regime by exploiting the Foldy-Wouthuysen scheme. The NC θ-effect appears from the replacement of normal products and commutators by Moyal *-products and *-commutators. In particular, the commutator between the external magnetic vector potential and the potential induced by acceleration becomes non-trivial. Expressions for θ-corrected inertial spin current and conductivity are derived explicitly. We have provided yet another way of experimentally measuring θ. The θ bound is obtained from the out of plane spin polarization, which is experimentally observable.
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.
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.
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.
Non-commutative tools for topological insulators
NASA Astrophysics Data System (ADS)
Prodan, Emil
2010-06-01
This paper reviews several analytic tools for the field of topological insulators, developed with the aid of non-commutative calculus and geometry. The set of tools includes bulk topological invariants defined directly in the thermodynamic limit and in the presence of disorder, whose robustness is shown to have nontrivial physical consequences for the bulk states. The set of tools also includes a general relation between the current of an observable and its edge index, a relation that can be used to investigate the robustness of the edge states against disorder. The paper focuses on the motivations behind creating such tools and on how to use them.
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…
Damage tolerance for commuter aircraft
NASA Technical Reports Server (NTRS)
Lincoln, John W.
1992-01-01
The damage tolerance experience in the United States Air Force with military aircraft and in the commercial world with large transport category aircraft indicates that a similar success could be achieved in commuter aircraft. The damage tolerance process is described for the purpose of defining the approach that could be used for these aircraft to ensure structural integrity. Results of some of the damage tolerance assessments for this class of aircraft are examined to illustrate the benefits derived from this approach. Recommendations are given for future damage tolerance assessment of existing commuter aircraft and on the incorporation of damage tolerance capability in new designs.
Commuter Family Relationships: Alive and Thriving.
ERIC Educational Resources Information Center
Johnson, Sharon Ervin
This study examined the impact that commuting, as part of a professional career lifestyle, has on family relationships. One hundred commuting couples participated in a paper and pencil survey. They responded to questions about coping as a family; dealing with the complications of children; keeping their relationship healthy; and commuting as a…
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…
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.
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. PMID:19540116
A Universal Model of Commuting Networks
Lenormand, Maxime; Huet, Sylvie; Gargiulo, Floriana; Deffuant, Guillaume
2012-01-01
We show that a recently proposed model generates accurate commuting networks on 80 case studies from different regions of the world (Europe and United-States) at different scales (e.g. municipalities, counties, regions). The model takes as input the number of commuters coming in and out of each geographic unit and generates the matrix of commuting flows between the units. The single parameter of the model follows a universal law that depends only on the scale of the geographic units. We show that our model significantly outperforms two other approaches proposing a universal commuting model [1], [2], particularly when the geographic units are small (e.g. municipalities). PMID:23049691
Imprecise probability for non-commuting observables
NASA Astrophysics Data System (ADS)
Allahverdyan, Armen E.
2015-08-01
It is known that non-commuting observables in quantum mechanics do not have joint probability. This statement refers to the precise (additive) probability model. I show that the joint distribution of any non-commuting pair of variables can be quantified via upper and lower probabilities, i.e. the joint probability is described by an interval instead of a number (imprecise probability). I propose transparent axioms from which the upper and lower probability operators follow. The imprecise probability depend on the non-commuting observables, is linear over the state (density matrix) and reverts to the usual expression for commuting observables.
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.
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.
Design criteria for brush commutation in high speed traveling wave coilguns
Snow, W.R.; Willig, R.L. )
1991-01-01
Barrel current in a traveling wave coilgun must be commutated on and off and remain synchronized with the position of the armature coils. Brushes on the armature can be used to satisfy these two requirements. First, they provide synchronization of the currents by being physically attached to the armature coil. Second, they provide a means of shorting the turns of the barrel so that motion induced commutation can take place. Motion induced commutation is the process where the current in a shorted barrel turn is caused to rise or fall because of the voltage induced by the moving armature. This change in barrel current must take place during the time the turn is shorted by the brush. Residual current in the trailing edge of the brush must be made small at the instant the circuit is opened to minimize arcing. A set of design criteria are presented for designing a brush commutated coilgun so as to achieve the required synchronous commutation. The design variables include the barrel coil configuration and its pitch, the armature coil configuration and its number of turns, and the brush length. The number of turns in the barrel undergoing commutation at the same instant in time is directly related to the length of the brush. In this paper the results of applying the design criteria to a specific design are presented.
Postarc phenomena in a diffuse self-commutating dc vacuum arc
Graneau, N. . Dept. of Engineering Science)
1989-10-01
Measurements have been made of the postarc chopping current of a self-commutating dc vacuum arc. Cathode current, anode current, and arc voltage, as well as ion current, to a grounded shield are monitored. A qualitative description of conditions in the gap is proposed, explaining the apparent current reversal observed.
8 CFR 211.5 - Alien commuters.
Code of Federal Regulations, 2013 CFR
2013-01-01
... shall be made in accordance with 8 CFR 264.5. ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent...
8 CFR 211.5 - Alien commuters.
Code of Federal Regulations, 2012 CFR
2012-01-01
... shall be made in accordance with 8 CFR 264.5. ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent...
8 CFR 211.5 - Alien commuters.
Code of Federal Regulations, 2014 CFR
2014-01-01
... shall be made in accordance with 8 CFR 264.5. ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Alien commuters. 211.5 Section 211.5 Aliens...: IMMIGRANTS; WAIVERS § 211.5 Alien commuters. (a) General. An alien lawfully admitted for permanent...
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…
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. PMID:26560311
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.
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.
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.
Covariant non-commutative space-time
NASA Astrophysics Data System (ADS)
Heckman, Jonathan J.; Verlinde, Herman
2015-05-01
We introduce a covariant non-commutative deformation of 3 + 1-dimensional conformal field theory. The deformation introduces a short-distance scale ℓp, and thus breaks scale invariance, but preserves all space-time isometries. The non-commutative algebra is defined on space-times with non-zero constant curvature, i.e. dS4 or AdS4. The construction makes essential use of the representation of CFT tensor operators as polynomials in an auxiliary polarization tensor. The polarization tensor takes active part in the non-commutative algebra, which for dS4 takes the form of so (5, 1), while for AdS4 it assembles into so (4, 2). The structure of the non-commutative correlation functions hints that the deformed theory contains gravitational interactions and a Regge-like trajectory of higher spin excitations.
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.
Non-commutativity measure of quantum discord.
Guo, Yu
2016-01-01
Quantum discord is a manifestation of quantum correlations due to non-commutativity rather than entanglement. Two measures of quantum discord by the amount of non-commutativity via the trace norm and the Hilbert-Schmidt norm respectively are proposed in this paper. These two measures can be calculated easily for any state with arbitrary dimension. It is shown by several examples that these measures can reflect the amount of the original quantum discord. PMID:27122226
Non-commutativity measure of quantum discord
Guo, Yu
2016-01-01
Quantum discord is a manifestation of quantum correlations due to non-commutativity rather than entanglement. Two measures of quantum discord by the amount of non-commutativity via the trace norm and the Hilbert-Schmidt norm respectively are proposed in this paper. These two measures can be calculated easily for any state with arbitrary dimension. It is shown by several examples that these measures can reflect the amount of the original quantum discord. PMID:27122226
Non-commutativity in the brain.
Tweed, D B; Haslwanter, T P; Happe, V; Fetter, M
1999-05-20
In non-commutative algebra, order makes a difference to multiplication, so that a x b not equal to b x a. This feature is necessary for computing rotary motion, because order makes a difference to the combined effect of two rotations. It has therefore been proposed that there are non-commutative operators in the brain circuits that deal with rotations, including motor circuits that steer the eyes, head and limbs, and sensory circuits that handle spatial information. This idea is controversial: studies of eye and head control have revealed behaviours that are consistent with non-commutativity in the brain, but none that clearly rules out all commutative models. Here we demonstrate non-commutative computation in the vestibulo-ocular reflex. We show that subjects rotated in darkness can hold their gaze points stable in space, correctly computing different final eye-position commands when put through the same two rotations in different orders, in a way that is unattainable by any commutative system. PMID:10353248
Nordfjærn, Trond; Simşekoğlu, Özlem; Lind, Hans Brende; Jørgensen, Stig Halvard; Rundmo, Torbjørn
2014-11-01
There is currently scant research on the role of transport priorities, risk perception and worry for travel mode use and preferences. The present study aims to examine these factors in relation to mode use and preferences among Norwegian commuters. A web-based survey was conducted in a randomly obtained representative sample of daily commuters in the extended greater Oslo area (n=690). The results showed that those who prioritized efficiency and flexibility tended to commute by car, while those who prioritized safety and comfort used public (e.g. metro, tram, and train) or active (e.g. walking and cycling) transport. In a free choice scenario, the respondents who prioritized flexibility reported a preference for using a car, whereas those who prioritized safety and comfort preferred public and active transport for their commuter travels. Risk perception of high impact events, such as terrorism and major accidents, as well as risk perception related to personal impact risks (theft, violence etc.) were related to car use on commuter travels. Transport-related worry exerted weak influences on mode use and preferences. Increased speed on rail transport and more frequent departures may be effective in reducing car use on commuter travels. Risk communication should focus on highlighting the low risk of experiencing security and safety issues in the public transport sector, and this message should be complemented by efforts to reduce the probability of negative events affecting public transport. PMID:25129446
Design criteria for brush commutation in high speed traveling wave coilguns
NASA Astrophysics Data System (ADS)
Snow, W. R.; Willig, R. L.
1991-01-01
Barrel current in a traveling wave coilgun must be commutated on and off, and remain synchronized with the position of the armature coils. Brushes on the armature can be used to satisfy these two requirements, providing synchronization of the currents by being physically attached to the armature coil and provide a means of shorting the turns of the barrel so that motion-induced commutation can take place. This change in barrel current must take place during the time the turn is shorted by the brush. Residual current in the trailing edge of the brush must be made small at the instant the circuit is opened to minimize arcing. A set of design criteria are presented for designing a brush-commutated coilgun so as to achieve the required synchronous commutation. The numer of turns in the barrel undergoing commutation at the same instant in time is directly related to the length of the brush. The results of applying the design criteria to a specific design are presented.
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…
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
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.
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
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)
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, 2010 CFR
2010-04-01
... qualifying commuter highway vehicle on the return for the taxable year in which the vehicle is placed in... 26 Internal Revenue 1 2010-04-01 2010-04-01 true Commuter highway vehicles. 1.46-11 Section 1.46... Rules for Computing Credit for Investment in Certain Depreciable Property § 1.46-11 Commuter...
26 CFR 1.46-11 - Commuter highway vehicles.
Code of Federal Regulations, 2011 CFR
2011-04-01
... qualifying commuter highway vehicle on the return for the taxable year in which the vehicle is placed in... 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...
26 CFR 1.46-11 - Commuter highway vehicles.
Code of Federal Regulations, 2014 CFR
2014-04-01
... qualifying commuter highway vehicle on the return for the taxable year in which the vehicle is placed in... 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...
26 CFR 1.46-11 - Commuter highway vehicles.
Code of Federal Regulations, 2012 CFR
2012-04-01
... qualifying commuter highway vehicle on the return for the taxable year in which the vehicle is placed in... 26 Internal Revenue 1 2012-04-01 2012-04-01 false Commuter highway vehicles. 1.46-11 Section 1.46... Rules for Computing Credit for Investment in Certain Depreciable Property § 1.46-11 Commuter...
26 CFR 1.46-11 - Commuter highway vehicles.
Code of Federal Regulations, 2013 CFR
2013-04-01
... qualifying commuter highway vehicle on the return for the taxable year in which the vehicle is placed in... 26 Internal Revenue 1 2013-04-01 2013-04-01 false Commuter highway vehicles. 1.46-11 Section 1.46... Rules for Computing Credit for Investment in Certain Depreciable Property § 1.46-11 Commuter...
Quantum Gibbs Samplers: The Commuting Case
NASA Astrophysics Data System (ADS)
Kastoryano, Michael J.; Brandão, Fernando G. S. L.
2016-05-01
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 {{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.
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.
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.
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.
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
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…
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
Mapping commuter cycling risk in urban areas.
Yiannakoulias, Nikolaos; Bennet, Scott A; Scott, Darren M
2012-03-01
Cycling is becoming an increasingly important transportation option for commuters. Cycling offers exercise opportunities and reduces the burden of motor vehicle travel on society. Mapping the risk of collision between cyclists and motor vehicles in urban areas is important to understanding safe cyclist route opportunities, making informed transportation planning decisions, and exploring patterns of injury epidemiology. To date, many geographic analyses and representations of cyclist risk have not taken the concept of exposure into account. Instead, risk is either expressed as a rate per capita, or as a count of events. Using data associated with the City of Hamilton, Canada, we illustrate a method for mapping commuter cyclist collision risk per distance travelled. This measure can be used to more realistically represent the underlying geography of cycling risk, and provide more geographically and empirically meaningful information to those interested in understanding how cycling safety varies over space. PMID:22269497
Delayed commutation in quantum computer networks.
García-Escartín, Juan Carlos; Chamorro-Posada, Pedro
2006-09-15
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. PMID:17025870
NASA Astrophysics Data System (ADS)
Kochubei, Anatoly N.
1996-10-01
Representations of the canonical and deformed commutation relations by bounded operators on p-adic Banach spaces are constructed. Functions from the Mahler basis of the space of p-adic continuous functions and their multiplicative analogues are shown to be the p-adic counterparts of the Hermite and q-Hermite functions. The analogue of the Stone - von Neumann uniqueness theorem fails in the p-adic case.
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.
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.
Non-commutativity from the double sigma model
NASA Astrophysics Data System (ADS)
Polyakov, Dimitri; Wang, Peng; Wu, Houwen; Yang, Haitang
2015-03-01
We show how non-commutativity arises from commutativity in the double sigma model. We demonstrate that this model is intrinsically non-commutative by calculating the propagators. In the simplest phase configuration, there are two dual copies of commutative theories. In general rotated frames, one gets a non-commutative theory and a commutative partner. Thus a non-vanishing B also leads to a commutative theory. Our results imply that O( D, D) symmetry unifies not only the big and small torus physics, but also the commutative and non-commutative theories. The physical interpretations of the metric and other parameters in the double sigma model are completely dictated by the boundary conditions. The open-closed relation is also an O( D, D) rotation and naturally leads to the Seiberg-Witten map. Moreover, after applying a second dual rotation, we identify the description parameter in the Seiberg-Witten map as an O( D, D) group parameter and all theories are non-commutative under this composite rotation. As a bonus, the propagators of general frames in double sigma model for open string are also presented.
[Tuberculosis microepidemic in a commuter bus].
Yagi, T; Sasaki, Y; Yamagishi, F; Mizutani, F; Wada, A; Kuroda, F
1999-06-01
A tuberculosis microepidemic in a commuter bus was reported. Index patient was a 22-year-old woman who was an employee of an electronic company. An abnormal shadow was found on her chest roentgenogram during an annual medical check-up in June, 1996. As her sputum smear was Gaffky 6, she was admitted to our hospital for medication. Extraordinary examinations including PPD skin test and chest X-ray were carried out on 49 employees of the company in October, 1996. As the result of these examinations, the distribution of maximum diameters of erythema in PPD skin test showed bimodal distribution, and tuberculosis was discovered in two patients by Chest X-ray examination. Moreover, preventive administration of Isonicotinic acid hydrazide (INH) was indicated for 3 employees based on very strong skin reaction to PPD. These five employees were working separately from the index patient and had little contact with the patient in the work places, but using a same commuter bus. Therefore, we strongly suspect that they were infected from the index patient not in the work place but in the commuter bus. The air-conditioning of the bus used a closed recirculation system, hence insufficient ventilation in the bus contributed to the spread of tuberculosis infection. PMID:10423962
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
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.
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.
Generalized Uncertainty Relations in the Non-commutative Plane
NASA Astrophysics Data System (ADS)
Chung, Won Sang
2015-09-01
In this paper we study two-dimensional noncommutative quantum mechanics (NCQM) with the generalized uncertainty relations . We find the new NCQM algebra from the generalized uncertainty relations. We construct a operator commuting with and discuss two possibilities; One is the case that also commutes with and another is the case that does not commute with . For both case we consider a motion of a charged particle in a magnetic field with a harmonic oscillator potential in the noncommutative plane.
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. PMID
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.
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.
75 FR 13680 - Commutation of Sentence: Technical Change
Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-23
... Bureau of Prisons 28 CFR Part 571 RIN 1120-AB54 Commutation of Sentence: Technical Change AGENCY: Bureau of Prisons, Justice. ACTION: Interim rule. SUMMARY: This document makes a minor technical change to the Bureau of Prisons (Bureau) regulations on sentence commutation to clarify that the Bureau...
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.
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…
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…
Inflation on a non-commutative space-time
NASA Astrophysics Data System (ADS)
Calmet, Xavier; Fritz, Christopher
2015-07-01
We study inflation on a non-commutative space-time within the framework of enveloping algebra approach which allows for a consistent formulation of general relativity and of the standard model of particle physics. We show that within this framework, the effects of the non-commutativity of spacetime are very subtle. The dominant effect comes from contributions to the process of structure formation. We describe the bound relevant to this class of non-commutative theories and derive the tightest bound to date of the value of the non-commutative scale within this framework. Assuming that inflation took place, we get a model independent bound on the scale of space-time non-commutativity of the order of 19 TeV.
Almost Commuting Unitary Matrices Related to Time Reversal
NASA Astrophysics Data System (ADS)
Loring, Terry A.; Sørensen, Adam P. W.
2013-11-01
The behavior of fermionic systems depends on the geometry of the system and the symmetry class of the Hamiltonian and observables. Almost commuting matrices arise from band-projected position observables in such systems. One expects the mathematical behavior of almost commuting Hermitian matrices to depend on two factors. One factor will be the approximate polynomial relations satisfied by the matrices. The other factor is what algebra the matrices are in, either for , or , the algebra of quaternions. There are potential obstructions keeping k-tuples of almost commuting operators from being close to a commuting k-tuple.We consider two-dimensional geometries and so this obstruction lives in . This obstruction corresponds to either the Chern number or spin Chern number in physics. We show that if this obstruction is the trivial element in K-theory then the approximation by commuting matrices is possible.
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.
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. PMID:20722227
ERIC Educational Resources Information Center
Gianoutsos, D.; Rosser, Vicki
2014-01-01
The purpose of the study is to compare the student profile characteristics, which were categorized as demographic, prematriculation, and matriculation, between traditional residential and commuter students at a public, research, commuter university. Using status attainment as the theoretical framework, the researchers employed a discriminant…
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.
Accelerating commutation circuits in quantum computer networks
NASA Astrophysics Data System (ADS)
Jiang, Min; Huang, Xu; Chen, Xiaoping; Zhang, Zeng-ke
2012-12-01
In a high speed and packet-switched quantum computer network, a packet routing delay often leads to traffic jams, becoming a severe bottleneck for speeding up the transmission rate. Based on the delayed commutation circuit proposed in Phys. Rev. Lett. 97, 110502 (2006), we present an improved scheme for accelerating network transmission. For two more realistic scenarios, we utilize the characteristic of a quantum state to simultaneously implement a data switch and transmission that makes it possible to reduce the packet delay and route a qubit packet even before its address is determined. This circuit is further extended to the quantum network for the transmission of the unknown quantum information. The analysis demonstrates that quantum communication technology can considerably reduce the processing delay time and build faster and more efficient packet-switched networks.
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.
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.
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
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.
Generalized Uncertainty Relation in the Non-commutative Quantum Mechanics
NASA Astrophysics Data System (ADS)
Chung, Won Sang
2016-06-01
In this paper the non-commutative quantum mechanics (NCQM) with the generalized uncertainty relations {Δ } x1 {Δ } x2 ≥ {θ}/{2}, {Δ} p1 {Δ } p2 ≥ {bar{θ}}/{2}, {Δ } xi {Δ } pi ≥ {hbar _{eff}}/{2} is discussed. Four each uncertainty relation, wave functions saturating each uncertainty relation are explicitly constructed. The unitary operators relating the non-commutative position and momentum operators to the commutative position and momentum operators are also investigated. We also discuss the uncertainty relation related to the harmonic oscillator.
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...
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, 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, 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, 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 23.574 - Metallic damage tolerance and fatigue evaluation of commuter category airplanes.
Code of Federal Regulations, 2010 CFR
2010-01-01
... evaluation of commuter category airplanes. 23.574 Section 23.574 Aeronautics and Space FEDERAL AVIATION... COMMUTER CATEGORY AIRPLANES Structure Fatigue Evaluation § 23.574 Metallic damage tolerance and fatigue evaluation of commuter category airplanes. For commuter category airplanes— (a) Metallic damage tolerance....
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, teleology and GRB time delay
NASA Astrophysics Data System (ADS)
Li, Miao; Pang, Yi; Wang, Yi
2010-01-01
We propose a model in which an energy-dependent time delay of a photon originates from space-time non-commutativity, the time delay is due to a non-commutative coupling between dilaton and photon. We predict that in our model, high energy photons with different momentum can either be delayed or superluminal, this may be related to a possible time delay reported by the Fermi LAT and Fermi GBM Collaborations.
A Homemade Autosampler/Injector Commutator for Flow Injection Analysis
de Figueiredo, Eduardo Costa; de Souza, Leandro Ruela; de Magalhães, Cristiana Schmidt; Wisniewski, Célio
2006-01-01
An autosampler/injector commutator for flow injection analysis (FIA) was constructed with electronic components of used equipments. The apparatus is controlled by commercially available multifunctional interface (PCL711B) connected to a personal computer, and the software was written in Visual Basic language. The system was applied to water analysis and it presented satisfactory results. The low cost and simplicity are the principal characteristics of the autosampler/injector commutator. PMID:17671617
Massive neutrinos in almost-commutative geometry
NASA Astrophysics Data System (ADS)
Stephan, Christoph A.
2007-02-01
In the noncommutative formulation of the standard model of particle physics by Chamseddine and Connes [Commun. Math. Phys. 182, 155 (1996), e-print hep-th/9606001], one of the three generations of fermions has to possess a massless neutrino. [C. P. Martin et al., Phys. Rep. 29, 363 (1998), e-print hep-th-9605001]. This formulation is consistent with neutrino oscillation experiments and the known bounds of the Pontecorvo-Maki-Nakagawa-Sakata matrix (PMNS matrix). But future experiments which may be able to detect neutrino masses directly and high-precision measurements of the PMNS matrix might need massive neutrinos in all three generations. In this paper we present an almost-commutative geometry which allows for a standard model with massive neutrinos in all three generations. This model does not follow in a straightforward way from the version of Chamseddine and Connes since it requires an internal algebra with four summands of matrix algebras, instead of three summands for the model with one massless neutrino.
Massive neutrinos in almost-commutative geometry
Stephan, Christoph A.
2007-02-15
In the noncommutative formulation of the standard model of particle physics by Chamseddine and Connes [Commun. Math. Phys. 182, 155 (1996), e-print hep-th/9606001], one of the three generations of fermions has to possess a massless neutrino. [C. P. Martin et al., Phys. Rep. 29, 363 (1998), e-print hep-th-9605001]. This formulation is consistent with neutrino oscillation experiments and the known bounds of the Pontecorvo-Maki-Nakagawa-Sakata matrix (PMNS matrix). But future experiments which may be able to detect neutrino masses directly and high-precision measurements of the PMNS matrix might need massive neutrinos in all three generations. In this paper we present an almost-commutative geometry which allows for a standard model with massive neutrinos in all three generations. This model does not follow in a straightforward way from the version of Chamseddine and Connes since it requires an internal algebra with four summands of matrix algebras, instead of three summands for the model with one massless neutrino.
Villa-González, Emilio; Ruiz, Jonatan R; Chillón, Palma
2015-09-01
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
Stabilizer of shaft rotation angle for D.C. commutator motor
NASA Astrophysics Data System (ADS)
Nizovoy, S. N.; Kuliczhanov, F. G.; Yelyutin, N. O.
1986-02-01
A stabilizer of shaft rotation angle for d.c. commutator motors is described which suppresses speed fluctuation caused by a change in the armature current as successive commutator bars reach the leading edge of a brush. This is achieved by inserting a low series resistance into the armature circuit and feeding the voltage across it to a servo oscillograph so that the frequency of the driven sweep becomes a multiple of the shaft speed. Return-stroke sweep pulses are extracted from the sawtooth voltage wave by a shaping circuit which consists of one capacitor, one resistor, two diodes, and one trigger. After a specified number of pulses has accumulated, another trigger actuates a switch which disconnects the motor from the voltage supply. A single starting pulse at the output of another shaping circuit records a specified number in the same pulse counter, through arrays of switches, and sets the same trigger for reconnecting the motor to the voltage supply. This stabilizer was tested on a positioning table driven by an MN-250 motor with 6-bar commutator, using an S1-19B oscillograph. The motor was started in steps for rotation in 3 minute steps, and the table position was measured after each 20 steps by means of a theodolite within + or - 4 sec accuracy. The average instability of the rotation angle between measurements did not exceed + or 30 sec.
Improving reversal median computation using commuting reversals and cycle information.
Arndt, William; Tang, Jijun
2008-10-01
In the past decade, genome rearrangements have attracted increasing attention from both biologists and computer scientists as a new type of data for phylogenetic analysis. Methods for reconstructing phylogeny from genome rearrangements include distance-based methods, MCMC methods, and direct optimization methods. The latter, pioneered by Sankoff and extended with the software suites GRAPPA and MGR, is the most accurate approach, but is very limited due to the difficulty of its scoring procedure--it must solve multiple instances of the reversal median problem to compute the score of a given tree. The reversal median problem is known to be NP-hard and all existing solvers are extremely slow when the genomes are distant. In this paper, we present a new reversal median heuristic for unichromosomal genomes. The new method works by applying sets of reversals in a batch where all such reversals both commute and do not break the cycle of any other. Our testing using simulated datasets shows that this method is much faster than the leading solver for difficult datasets with only a slight accuracy penalty, yet retains better accuracy than other heuristics with comparable speed, and provides the additional option of searching for multiple medians. This method dramatically increases the speed of current direct optimization methods and enables us to extend the range of their applicability to organellar and small nuclear genomes with more than 50 reversals along each edge. PMID:18774904
The active commuting route environment scale (ACRES): development and evaluation
2010-01-01
Background Route environments can be a potentially important factor in influencing people's behaviours in relation to active commuting. To better understand these possible relationships, assessments of route environments are needed. We therefore developed a scale; the Active Commuting Route Environment Scale (ACRES), for the assessment of bicyclists' and pedestrians' perceptions of their commuting route environments. Here we will report on the development and the results of validity and reliability assessments thereof. Methods Active commuters (n = 54) were recruited when they bicycled in Stockholm, Sweden. Traffic planning and environmental experts from the Municipality of Stockholm were assembled to form an expert panel (n = 24). The active commuters responded to the scale on two occasions, and the expert panel responded to it once. To test criterion-related validity, differences in ratings of the inner urban and suburban environments of Greater Stockholm were compared between the experts and the commuters. Furthermore, four items were compared with existing objective measures. Test-retest reproducibility was assessed with three types of analysis: order effect, typical error and intraclass correlation. Results There was a concordance in sizes and directions of differences in ratings of inner urban and suburban environments between the experts and the commuters. Furthermore, both groups' ratings were in line with existing objectively measured differences between the two environmental settings. Order effects between test and retest were observed in 6 of 36 items. The typical errors ranged from 0.93 to 2.54, and the intraclass correlation coefficients ranged from 'moderate' (0.42) to 'almost perfect' (0.87). Conclusions The ACRES was characterized by considerable criterion-related validity and reasonable test-retest reproducibility. PMID:20609250
Geometric properties of commutative subalgebras of partial differential operators
NASA Astrophysics Data System (ADS)
Zheglov, A. B.; Kurke, H.
2015-05-01
We investigate further algebro-geometric properties of commutative rings of partial differential operators, continuing our research started in previous articles. In particular, we start to explore the simplest and also certain known examples of quantum algebraically completely integrable systems from the point of view of a recent generalization of Sato's theory, developed by the first author. We give a complete characterization of the spectral data for a class of 'trivial' commutative algebras and strengthen geometric properties known earlier for a class of known examples. We also define a kind of restriction map from the moduli space of coherent sheaves with fixed Hilbert polynomial on a surface to an analogous moduli space on a divisor (both the surface and the divisor are part of the spectral data). We give several explicit examples of spectral data and corresponding algebras of commuting (completed) operators, producing as a by-product interesting examples of surfaces that are not isomorphic to spectral surfaces of any (maximal) commutative ring of partial differential operators of rank one. Finally, we prove that any commutative ring of partial differential operators whose normalization is isomorphic to the ring of polynomials k \\lbrack u,t \\rbrack is a Darboux transformation of a ring of operators with constant coefficients. Bibliography: 39 titles.
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.
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.
Long-Distance Relationships in Dual-Career Commuter Couples: A Review of Counseling Issues.
ERIC Educational Resources Information Center
Rhodes, Angel R.
2002-01-01
The dual-career commuter couple is an alternative family configuration that continues to grow in number. Reviews the literature on dual-career commuter couples that has been published since 1982. Addresses the counseling issues of marital and family characteristics, commuting characteristics, and decision-making styles. Counseling implications and…
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, 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...
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...
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...
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...
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...
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.…
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...
ERIC Educational Resources Information Center
Yearwood, Trina Lynn
2011-01-01
Although Black commuter students are disadvantaged when it comes to higher education, research on the success of Black commuter students in college is very rare. Existing research on Black and commuter students primarily concentrate on negative statistics such as stagnant college completion rates, departure, and lack of engagement. The purpose of…
49 CFR 37.87 - Purchase or lease of used intercity and commuter rail cars.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 1 2010-10-01 2010-10-01 false Purchase or lease of used intercity and commuter....87 Purchase or lease of used intercity and commuter rail cars. (a) Except as provided elsewhere in... may purchase or lease a used intercity or commuter rail car that is not readily accessible to...
49 CFR 37.87 - Purchase or lease of used intercity and commuter rail cars.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 1 2014-10-01 2014-10-01 false Purchase or lease of used intercity and commuter....87 Purchase or lease of used intercity and commuter rail cars. (a) Except as provided elsewhere in... may purchase or lease a used intercity or commuter rail car that is not readily accessible to...
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...
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...
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.
Components of a Comprehensive Market Research Program for Commuter Colleges.
ERIC Educational Resources Information Center
Clagett, Cragi
1999-01-01
Describes and evaluates eight elements of a comprehensive market-research program for commuter colleges: secondary research with formal environmental scanning, local business community-needs assessment; adult community-member telephone survey, classroom survey, new student survey, focus groups, brainstorming sessions, and survey of college…
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.
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…
Using a PFET To Commutate an SCR
NASA Technical Reports Server (NTRS)
Edwards, D. B.; Ripple, W. E.
1984-01-01
Accidental turn-on prevented. PFET diverts load current around SCR to prevent false SCR triggering from current and voltage switching transients. New circuit used in all types of single phase and polyphase inverters and in buck-boost-, and flyback regulators.
Longitudinal associations of active commuting with wellbeing and sickness absence
Mytton, Oliver Tristan; Panter, Jenna; Ogilvie, David
2016-01-01
Objective Our aim was to explore longitudinal associations of active commuting (cycling to work and walking to work) with physical wellbeing (PCS-8), mental wellbeing (MCS-8) and sickness absence. Method We used data from the Commuting and Health in Cambridge study (2009 to 2012; n = 801) to test associations between: a) maintenance of cycling (or walking) to work over a one year period and indices of wellbeing at the end of that one year period; and b) associations between change in cycling (or walking) to work and change in indices of wellbeing. Linear regression was used for testing associations with PCS-8 and MCS-8, and negative binomial regression for sickness absence. Results After adjusting for sociodemographic variables, physical activity and physical limitation, those who maintained cycle commuting reported lower sickness absence (0.46, 95% CI: 0.14–0.80; equivalent to one less day per year) and higher MCS-8 scores (1.50, 0.10–2.10) than those who did not cycle to work. The association for sickness absence persisted after adjustment for baseline sickness absence. No significant associations were observed for PCS-8. Associations between change in cycle commuting and change in indices of wellbeing were not significant. No significant associations were observed for walking. Conclusions This work provides some evidence of the value of cycle commuting in improving or maintaining the health and wellbeing of adults of working age. This may be important in engaging employers in the promotion of active travel and communicating the benefits of active travel to employees. PMID:26740344
ERIC Educational Resources Information Center
Ward, Richard F.; Kurz, Theodore E.
The urban university campus is studied through a comprehensive view of student patterns. Following an analysis of the life patterns of the commuting student with regard to schedule, environment, and adequacy of educational facilities, recommendations are presented for a number of campus facilities to house activities considered beneficial to the…
Relationships Between Commuting and Social Capital Among Men and Women in Southern Sweden
Håkansson, Carita; Jakobsson, Kristina
2015-01-01
The societal need for a mobile workforce increases time spent commuting and thus also the total workday. How this affects individual well-being and social life is, however, surprisingly little known. We investigated the relation between commuting time and mode, and social participation and general trust in other people as measures of social capital, using data from public health surveys conducted in 2004 and 2008 in Scania, Sweden: in all, 21,088 persons ages 18 to 65 and working at least 30 hr per week. Commuting by car was significantly associated with a higher prevalence of low social participation and low general trust compared with active commuting, and the association increased with the duration of commuting time. In contrast, public commuting was not significantly associated with decreased social capital measures except among long-duration commuters, who reported lower social participation. The overall pattern was similar for men and for women. PMID:26273107
Étude des perturbations conduites et rayonnées dans une cellule de commutation
NASA Astrophysics Data System (ADS)
Costa, F.; Forest, F.; Puzo, A.; Rojat, G.
1993-12-01
The principles used in static conversion and the rise of the performances of the new switching devices contribue to increase the level of electromagnetic noises emitted by electronic converters. We have studied the way how these perturbations are created and coupled through their environment in conducted and radiated mode by a switching cell. This one can work in hard switching, zero current or voltage switching modes. We first outline the general problems of electromagnetic pollution and their metrology in converters. Then we describe the experimental environment. We analyse the mechanisms of generation of parasitic signals in a switching cell related to the electrical constraints and its switching mode. The simulated results, issued of the analytical models obtained, are confronted with the experimental ones. Then we show a method to calculate analytically the E and H near fields. It has been confirmed by experimental results. At last, we present, in a synthetic manner, the main results obtained, relative to the switching mode and the electrical constraints, using a new characterizing method. Theses results will allow the designer to incorporate the electromagnetic considerations in the conception of a converter. Les principes de commutation employés en conversion statique, l'évolution des performances statiques et dynamiques des composants, contribuent à faire des dispositifs de conversion statique de puissants générateurs de perturbations conduites et rayonnées. Nous nous sommes attachés à étudier les mécanismes de génération et de couplage des perturbations, tant en mode conduit que rayonné dans des structures à une seule cellule de commutation et fonctionnant selon les trois principaux modes de commutation : commutation forcée, à zéro de courant (ZCS), et à zéro de tension (ZVS). Après la mise en évidence de la problématique de pollution électromagnétique dans les structures et leur métrologie, nous décrivons l'environnement exp
Fransen, Koos; Neutens, Tijs; De Maeyer, Philippe; Deruyter, Greet
2015-03-01
This paper puts forward a commuter-based version of the two-step floating catchment area (2SFCA) method, which has gained acceptance in studies on spatial health care accessibility. Current implementations of the 2SFCA method are static in that they consider centroid-based night-time representations of the population. The proposed enhancement to the 2SFCA approach addresses this limitation by accounting for trip-chaining behavior. The presented method is illustrated in a case study of accessibility of daycare centers in the province East Flanders in Belgium. The results show significant spatial differences in accessibility between the original and commuter-based version of the 2SFCA (CB2SFCA). They highlight the importance of giving heed to more complex travel behavior in cases where the need for detailed accessibility calculations is apparent. PMID:25638791
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)...
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.
Commuter exposure to volatile organic compounds under different driving conditions
NASA Astrophysics Data System (ADS)
Jo, Wan-Kuen; Park, Kun-Ho
The driving conditions that were tested for the in-vehicle concentrations of selected volatile organic compounds (VOCs) included transport modes, fuel distributions, vehicle ventilation conditions, driving routes, commute seasons, car models, and driving periods. This study involved two sampling seasons (winter and summer). The in-auto/in-bus/fixed site ratio of the wintertime mean concentrations was about 6/3/1 for total VOCs and 8/3/1 for benzene. On the median, the in-auto/in-bus exposure ratio ranged from 1.5 to 2.8 for the morning commutes, and ranged from 2.4 to 4.5 for evening commutes, depending on the target compounds. The wintertime in-auto concentrations were significantly higher ( p<0.05), on the average 3-5 times higher, in a carbureted engine than in the three electronic fuel-injected cars. For the summertime in-auto concentrations of the target compounds except benzene, there were no significant differences between low and high ventilation conditions on the two urban routes. The urban in-auto benzene concentration was significantly higher ( p<0.05) under the low ventilation condition. For the rural commutes, the in-auto concentrations of all target compounds were significantly higher ( p<0.05) under the low ventilation condition. The in-auto VOC concentrations on the two urban routes did not differ significantly, and they were greater than the rural in-auto concentrations, with the differences being significant ( p<0.05) for all target compounds. The summertime in-auto concentrations of benzene and toluene were greater than the wintertime in-auto concentrations, with the difference being significant ( p<0.05), while the concentrations of the other target compounds were not significantly different between the two seasons. Neither car models nor driving periods influenced the in-auto VOC concentrations.
Two Dimensional Non-commutative Space and Rydberg Atom Model
NASA Astrophysics Data System (ADS)
Chung, Won Sang
2015-06-01
In this paper we consider the case of only space-space non-commutativity in two dimension. We also discuss the Rydberg atom model in this space and use the linear realization of the coordinate and momentum operators to solve the Schrödinger equation for the Rydberg atom through the standard perturbation method. Finally, the thermodynamics for the Rydberg atom model is discussed.
Commutability of Cytomegalovirus WHO International Standard in Different Matrices.
Jones, Sara; Webb, Erika M; Barry, Catherine P; Choi, Won S; Abravaya, Klara B; Schneider, George J; Ho, Shiaolan Y
2016-06-01
Commutability of quantitative standards allows patient results to be compared across molecular diagnostic methods and laboratories. This is critical to establishing quantitative thresholds for use in clinical decision-making. A matrix effect associated with the 1st cytomegalovirus (CMV) WHO international standard (IS) was identified using the Abbott RealTime CMV assay. A commutability study was performed to compare the CMV WHO IS and patient specimens diluted in plasma and whole blood. Patient specimens showed similar CMV DNA quantitation values regardless of the diluent or extraction procedure used. The CMV WHO IS, on the other hand, exhibited a matrix effect. The CMV concentration reported for the WHO IS diluted in plasma was within the 95% prediction interval established with patient samples. In contrast, the reported DNA concentration of the CMV WHO IS diluted in whole blood was reduced approximately 0.4 log copies/ml, and values fell outside the 95% prediction interval. Calibrating the assay by using the CMV WHO IS diluted in whole blood would introduce a bias for CMV whole-blood quantitation; samples would be reported as having higher measured concentrations, by approximately 0.4 log IU/ml. Based on the commutability study with patient samples, the RealTime CMV assay was standardized based on the CMV WHO IS diluted in plasma. A revision of the instructions for use of the CMV WHO IS should be considered to alert users of the potential impact from the diluent matrix. The identification of a matrix effect with the CMV WHO IS underscores the importance of assessing commutability of the IS in order to achieve consistent results across methods. PMID:27030491
Commutability of Cytomegalovirus WHO International Standard in Different Matrices
Jones, Sara; Webb, Erika M.; Barry, Catherine P.; Choi, Won S.; Abravaya, Klara B.; Schneider, George J.
2016-01-01
Commutability of quantitative standards allows patient results to be compared across molecular diagnostic methods and laboratories. This is critical to establishing quantitative thresholds for use in clinical decision-making. A matrix effect associated with the 1st cytomegalovirus (CMV) WHO international standard (IS) was identified using the Abbott RealTime CMV assay. A commutability study was performed to compare the CMV WHO IS and patient specimens diluted in plasma and whole blood. Patient specimens showed similar CMV DNA quantitation values regardless of the diluent or extraction procedure used. The CMV WHO IS, on the other hand, exhibited a matrix effect. The CMV concentration reported for the WHO IS diluted in plasma was within the 95% prediction interval established with patient samples. In contrast, the reported DNA concentration of the CMV WHO IS diluted in whole blood was reduced approximately 0.4 log copies/ml, and values fell outside the 95% prediction interval. Calibrating the assay by using the CMV WHO IS diluted in whole blood would introduce a bias for CMV whole-blood quantitation; samples would be reported as having higher measured concentrations, by approximately 0.4 log IU/ml. Based on the commutability study with patient samples, the RealTime CMV assay was standardized based on the CMV WHO IS diluted in plasma. A revision of the instructions for use of the CMV WHO IS should be considered to alert users of the potential impact from the diluent matrix. The identification of a matrix effect with the CMV WHO IS underscores the importance of assessing commutability of the IS in order to achieve consistent results across methods. PMID:27030491
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.
Marginal Consistency: Upper-Bounding Partition Functions over Commutative Semirings.
Werner, Tomás
2015-07-01
Many inference tasks in pattern recognition and artificial intelligence lead to partition functions in which addition and multiplication are abstract binary operations forming a commutative semiring. By generalizing max-sum diffusion (one of convergent message passing algorithms for approximate MAP inference in graphical models), we propose an iterative algorithm to upper bound such partition functions over commutative semirings. The iteration of the algorithm is remarkably simple: change any two factors of the partition function such that their product remains the same and their overlapping marginals become equal. In many commutative semirings, repeating this iteration for different pairs of factors converges to a fixed point when the overlapping marginals of every pair of factors coincide. We call this state marginal consistency. During that, an upper bound on the partition function monotonically decreases. This abstract algorithm unifies several existing algorithms, including max-sum diffusion and basic constraint propagation (or local consistency) algorithms in constraint programming. We further construct a hierarchy of marginal consistencies of increasingly higher levels and show than any such level can be enforced by adding identity factors of higher arity (order). Finally, we discuss instances of the framework for several semirings, including the distributive lattice and the max-sum and sum-product semirings. PMID:26352452
[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. PMID:24175530
Magnetic-free non-reciprocity based on staggered commutation
NASA Astrophysics Data System (ADS)
Reiskarimian, Negar; Krishnaswamy, Harish
2016-04-01
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.
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
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. PMID:27278365
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
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.
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".
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. PMID:22689293
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, 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...
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, 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...
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. PMID:20966368
Direct-drive digitally-commutated filter wheel positioning system for cryogenic optical applications
NASA Astrophysics Data System (ADS)
Lorell, Kenneth R.; Aubrun, Jean-Noel; Opyd, Walter G.; Wood, Allen D.
1993-01-01
A control system is presented for precise and rapid positioning of spectral filters in the multispectral infrared optical system used for the MUlti-Spectral Infrared Camera (MUSIC). A hybrid system employing a stepper motor as a direct-drive brushless servomotor presents an ideal solution, applying high torque at low speed for the optimum response as limited by available torque. As the end of the repositioning transient is approached, closed-loop proportional control of torque provides quick settling to a positioning accuracy of 0.02 degrees. The use of a stepper motor avoids the problems of a brushed DC servomotor, such as brush and bearing failures at high speeds in a cryogenic vacuum, and backlash in reduction gears. The analog servo loop with commutation hardware to optimally switch the current to the stepper motor windings, avoids problems typical of stepper motors, such as limited positioning precision and high power dissipation while holding position.
Small engine technology payoffs for future commuter aircraft
NASA Technical Reports Server (NTRS)
Kaehler, H.; Schneider, W.
1986-01-01
High payoff technologies for a year 2000 regenerative cycle turboprop engine were identified for a 19 passenger commuter aircraft application. A series of engines incorporating eight levels of advanced technologies were studied and their impact on aircraft performance was evaluated. Four advanced technologies are recommended to achieve a potential reduction in fuel burn of 38.3 percent. At $1.00 per gallon fuel price, a potential direct operating cost (DOC) benefit of 12.5 percent is obtained. At $2.00 per gallon, the potential DOC benefit increases to 17.0 percent.
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
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.
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.
Finite axionic electrodynamics from a new non-commutative approach
NASA Astrophysics Data System (ADS)
Gaete, Patricio; Spallucci, Euro
2012-02-01
Using the gauge-invariant but path-dependent variable formalism, we compute the static quantum potential for non-commutative axionic electrodynamics (or axionic electrodynamics in the presence of a minimal length). Accordingly, we obtain an ultraviolet finite static potential that is the sum of a Yukawa-type potential and a linear potential, leading to the confinement of static charges. Interestingly, it should be noted that this calculation involves no θ expansion at all. The present result manifests the key role played by the new quantum of length in our analysis.
On the essential spectrum of certain non-commutative oscillators
Parmeggiani, Alberto Venni, Alberto
2013-12-15
We show here that the spectrum of the family of non-commutative harmonic oscillators Q{sub (α,β)}{sup w}(x,D) for α,β∈R{sub +} in the range αβ = 1 is [0, +∞) and is entirely essential spectrum. The previous existing results concern the case αβ > 1 (case in which Q{sub (α,β)}{sup w}(x,D) is globally elliptic with a discrete spectrum whose qualitative properties are being extensively studied), and ours therefore extend the picture to the range of parameters αβ ⩾ 1.
Commuting mode and pulmonary function in Shanghai, China.
Gaffney, Adam W; Hang, Jing-Qing; Lee, Mi-Sun; Su, Li; Zhang, Feng-Ying; Christiani, David C
2016-03-01
Exposure to air pollution can be particularly high during commuting and may depend on the mode of transportation. We investigated the impact of commuting mode on pulmonary function in Shanghai, China.The Shanghai Putuo Study is a cross-sectional, population-based study. Our primary outcomes were forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) % predicted, and the secondary outcome was spirometric airflow obstruction. We tested the association between mode of transportation and these outcomes after adjusting for confounders.The study population consisted of 20 102 subjects. After adjusting for confounders, the change (95% CI) in FEV1 was -2.15% pred (-2.88- -1.42% pred) among pedestrians, -1.32% pred (-2.05- -0.59% pred) among those taking buses without air conditioning, -1.33% pred (-2.05- -0.61% pred) among those taking buses with air conditioning and -2.83% pred (-5.56- -0.10% pred) among those using underground railways, as compared to cyclists (the reference group). The effects of mode on FVC % predicted were in the same direction. Private car use had a significant protective effect on FVC % predicted and the risk of airflow obstruction (defined by Global Initiative for Chronic Obstructive Lung Disease but not by lower limit of normal criteria).Mode of transportation is associated with differences in lung function, which may reflect pollution levels in different transportation microenvironments. PMID:26541519
Analysis of a fuel cell hybrid commuter railway vehicle
NASA Astrophysics Data System (ADS)
Meegahawatte, Danushka; Hillmansen, Stuart; Roberts, Clive; Falco, Marco; McGordon, Andrew; Jennings, Paul
This study presents paper presents an analysis of the potential CO 2 savings that could be gained through the introduction of hydrogen-powered fuel cells on a commuter-style railway route. Vehicle is modelled as a fuel cell series hybrid. The analysis consists of power/energy flow models of a fuel cell stack, battery pack and hybrid drive controller. The models are implemented in a custom C# application and are capable of providing key parametric information of the simulated journey and individual energy drive components. A typical commuter return journey between Stratford Upon Avon and Birmingham is investigated. The fuel cell stack and battery pack behaviour is assessed for different stack sizes, battery sizes and control strategies to evaluate the performance of the overall system with the aim of understanding the optimum component configuration. Finally, the fuel (H 2) requirements are compared with typical diesel and hybrid-diesel powered vehicles with the aim of understanding the potential energy savings gained from such a fuel cell hybrid vehicle.
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.
Differences in active commuting among younger and older adults.
Bopp, Melissa; Der Ananian, Cheryl; Campbell, Matthew E
2014-04-01
The demonstrated health benefits of active commuting (AC) and low participation rates among older adults indicate a need to examine the socioecological correlates of AC by age category. An online survey of employed U.S. adults examined AC participation and individual, employment-related, community, and environmental variables. Participants were dichotomized by age (younger: 18-49 yr; n = 638, 64% and older: ≥ 50 yr; n = 359, 36%). Logistic-regression analyses examined differences in AC correlates by age. Older adults were less likely to be active commuters (13.4%) than younger adults (27.9%; p < .001) For older adults, analyses yielded a Nagelkerke R2 = .76, with perceived behavioral control, behavioral beliefs, household cars, and walking distance as predictors. Analyses for younger adults resulted in a Nagelkerke R2 = .79, with perceived behavioral control, coworker normative beliefs, parking problems at work, greater employer and community support for AC, and bad weather as predictors. Findings suggest age should be considered when examining and targeting AC behaviors. PMID:23689245
Piecewise Principal Coactions of Co-Commutative Hopf Algebras
NASA Astrophysics Data System (ADS)
Zieliński, Bartosz
2014-08-01
Principal comodule algebras can be thought of as objects representing principal bundles in non-commutative geometry. A crucial component of a principal comodule algebra is a strong connection map. For some applications it suffices to prove that such a map exists, but for others, such as computing the associated bundle projectors or Chern-Galois characters, an explicit formula for a strong connection is necessary. It has been known for some time how to construct a strong connection map on a multi-pullback comodule algebra from strong connections on multi-pullback components, but the known explicit general formula is unwieldy. In this paper we derive a much easier to use strong connection formula, which is not, however, completely general, but is applicable only in the case when a Hopf algebra is co-commutative. Because certain linear splittings of projections in multi-pullback comodule algebras play a crucial role in our construction, we also devote a significant part of the paper to the problem of existence and explicit formulas for such splittings. Finally, we show example application of our work.
Dissipative and nonunitary solutions of operator commutation relations
NASA Astrophysics Data System (ADS)
Makarov, K. A.; Tsekanovskii, E.
2016-01-01
We study the (generalized) semi-Weyl commutation relations UgAU* g = g(A) on Dom(A), where A is a densely defined operator and G ∋ g ↦ Ug is a unitary representation of the subgroup G of the affine group G, the group of affine orientation-preserving transformations of the real axis. If A is a symmetric operator, then the group G induces an action/flow on the operator unit ball of contracting transformations from Ker(A* - iI) to Ker(A* + iI). We establish several fixed-point theorems for this flow. In the case of one-parameter continuous subgroups of linear transformations, self-adjoint (maximal dissipative) operators associated with the fixed points of the flow yield solutions of the (restricted) generalized Weyl commutation relations. We show that in the dissipative setting, the restricted Weyl relations admit a variety of representations that are not unitarily equivalent. For deficiency indices (1, 1), the basic results can be strengthened and set in a separate case.
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. PMID:21830871
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
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.
Urban Corridor Consortium Task Force on Part-Time and Commuter Students. Final Report.
ERIC Educational Resources Information Center
Wisconsin Univ. Urban Corridor Consortium.
Ways that urban corridor campuses might respond to the increasing enrollment of part-time and commuter students were reviewed by the University of Wisconsin Urban Corridor Consortium Task Force on Part-Time and Commuter Students. Members of the consortia are the following University of Wisconsin campuses: Green Bay, Milwaukee, Oshkosh, Parkside,…
Active commuting to school and association with physical activity and adiposity among US youth
Technology Transfer Automated Retrieval System (TEKTRAN)
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...
Code of Federal Regulations, 2013 CFR
2013-01-01
... affecting § 21.183, see the List of CFR Sections Affected, which appears in the Finding Aids section of the... certificates for normal, utility, acrobatic, commuter, and transport category aircraft; manned free balloons..., commuter, and transport category aircraft; manned free balloons; and special classes of aircraft. (a)...
Code of Federal Regulations, 2010 CFR
2010-01-01
... § 21.183, see the List of CFR Sections Affected, which appears in the Finding Aids section of the... certificates for normal, utility, acrobatic, commuter, and transport category aircraft; manned free balloons..., commuter, and transport category aircraft; manned free balloons; and special classes of aircraft. Link...
Code of Federal Regulations, 2014 CFR
2014-01-01
... affecting § 21.183, see the List of CFR Sections Affected, which appears in the Finding Aids section of the... certificates for normal, utility, acrobatic, commuter, and transport category aircraft; manned free balloons..., commuter, and transport category aircraft; manned free balloons; and special classes of aircraft. (a)...
Adding flavor to the gravity dual of non-commutative gauge theories
NASA Astrophysics Data System (ADS)
Areán, Daniel; Paredes, Angel; Ramallo, Alfonso V.
2005-08-01
We study the addition of flavor degrees of freedom to the supergravity dual of the non-commutative deformation of the maximally supersymmetric gauge theories. By considering D7 flavor branes in the probe approximation and studying their fluctuations we extract the spectrum of scalar and vector mesons as a function of the non-commutativity. We find that the spectrum for very large non-commutative parameter is equal to the one in the commutative theory, while for some intermediate values of the non-commutativity some of the modes disappear from the discrete spectrum. We also study the semiclassical dynamics of rotating open strings attached to the D7-brane, which correspond to mesons with large spin. Under the effect of the non-commutativity the open strings get tilted. However, at small(large) distances they display the same Regge-like (Coulombic) behaviour as in the commutative theory. We also consider the addition of D5-flavor branes to the non-commutative deformation of the Script N = 1 supersymmetric Maldacena-Núñez background.
Real hypersurfaces in the complex quadric with commuting and parallel Ricci tensor
NASA Astrophysics Data System (ADS)
Suh, Young Jin
2016-08-01
First we introduce the notion of commuting and parallel Ricci tensor for real hypersurfaces in the complex quadric Qm = SOm+2 / SO2 SOm. Then, according to the A-isotropic unit normal N, we give a complete classification of real hypersurfaces in Qm = SOm+2 / SO2 SOm with commuting and parallel Ricci tensor.
CARBON MONOXIDE COMMUTER EXPOSURE DATA BASE: A 5-DAY STUDY IN LOS ANGELES
Recent concern about carbon monoxide exposure to the commuter population prompted the U.S. Environmental Protection Agency to conduct a five-day field project to assess the CO exposure to Los Angeles commuters. The purpose of this report is to document the field project and to pr...
Abeynayake, Janaki; Johnson, Ryan; Libiran, Paolo; Sahoo, Malaya K; Cao, Hongbin; Bowen, Raffick; Chan, K C Allen; Le, Quynh-Thu; Pinsky, Benjamin A
2014-10-01
The commutability of international reference standards is critical for ensuring quantitative agreement across different viral load assays. Here, we demonstrate the commutability of the Epstein-Barr virus (EBV) WHO international standard for the BamHI-W and artus EBV assays. PMID:25078918
49 CFR 37.51 - Key stations in commuter rail systems.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 1 2013-10-01 2013-10-01 false Key stations in commuter rail systems. 37.51... INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities § 37.51 Key stations in commuter rail systems. (a) The responsible person(s) shall make key stations on its system readily accessible to and...
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... INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities § 37.51 Key stations in commuter rail systems. (a) The responsible person(s) shall make key stations on its system readily accessible to and...
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... INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities § 37.51 Key stations in commuter rail systems. (a) The responsible person(s) shall make key stations on its system readily accessible to and...
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... INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities § 37.51 Key stations in commuter rail systems. (a) The responsible person(s) shall make key stations on its system readily accessible to and...
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... INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities § 37.51 Key stations in commuter rail systems. (a) The responsible person(s) shall make key stations on its system readily accessible to and...
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.
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.
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
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
ERIC Educational Resources Information Center
Rungeling, Brian Scott
This study analyzed what effect commuters had on wage levels, employment, and industrial locations, and the relative importance of the commuter as part of the work force. A questionnaire was administered to 190 workers and to their 20 employers in the apparel industry of El Paso, Texas. The questionnaires revealed that the commuters were paid the…
Optimal Scale of a Public Elementary School with Commuting Costs-A Case Study of Taipei County
ERIC Educational Resources Information Center
Tao, H.-L.; Yuan, M.-C.
2005-01-01
This study demonstrates the importance of commuting costs while determining the optimal school scale. It is found that, without commuting costs, the elementary schools in Taipei county are characterized by increasing returns to scale, and that the average public cost curve is L-shaped. However, ignoring the costs of commuting implies that the…
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
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.
Commuting Pauli Hamiltonians as Maps between Free Modules
NASA Astrophysics Data System (ADS)
Haah, Jeongwan
2013-12-01
We study unfrustrated spin Hamiltonians that consist of commuting tensor products of Pauli matrices. Assuming translation-invariance, a family of Hamiltonians that belong to the same phase of matter is described by a map between modules over the translation-group algebra, so homological methods are applicable. In any dimension every point-like charge appears as a vertex of a fractal operator, and can be isolated with energy barrier at most logarithmic in the separation distance. For a topologically ordered system in three dimensions, there must exist a point-like nontrivial charge. A connection between the ground state degeneracy and the number of points on an algebraic set is discussed. Tools to handle local Clifford unitary transformations are given.
Quantized chaotic dynamics and non-commutative KS entropy
Klimek, S.; Lesniewski, A.
1996-06-01
We study the quantization of two examples of classically chaotic dynamics, the Anosov dynamics of {open_quote}{open_quote}cat maps{close_quote}{close_quote} on a two dimensional torus, and the dynamics of baker{close_quote}s maps. Each of these dynamics is implemented as a discrete group of automorphisms of a von Neumann algebra of functions on a quantized torus. We compute the non-commutative generalization of the Kolmogorov-Sinai entropy, namely the Connes-Sto/rmer entropy, of the generator of this group, and find that its value is equal to the classical value. This can be interpreted as a sign of persistence of chaotic behavior in a dynamical system under quantization. Copyright {copyright} 1996 Academic Press, Inc.
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.
Investigation of Commuting Hamiltonian in Quantum Markov Network
NASA Astrophysics Data System (ADS)
Jouneghani, Farzad Ghafari; Babazadeh, Mohammad; Bayramzadeh, Rogayeh; Movla, Hossein
2014-08-01
Graphical Models have various applications in science and engineering which include physics, bioinformatics, telecommunication and etc. Usage of graphical models needs complex computations in order to evaluation of marginal functions, so there are some powerful methods including mean field approximation, belief propagation algorithm and etc. Quantum graphical models have been recently developed in context of quantum information and computation, and quantum statistical physics, which is possible by generalization of classical probability theory to quantum theory. The main goal of this paper is preparing a primary generalization of Markov network, as a type of graphical models, to quantum case and applying in quantum statistical physics. We have investigated the Markov network and the role of commuting Hamiltonian terms in conditional independence with simple examples of quantum statistical physics.
Monte Carlo simulations of random non-commutative geometries
NASA Astrophysics Data System (ADS)
Barrett, John W.; Glaser, Lisa
2016-06-01
Random non-commutative geometries are introduced by integrating over the space of Dirac operators that form a spectral triple with a fixed algebra and Hilbert space. The cases with the simplest types of Clifford algebra are investigated using Monte Carlo simulations to compute the integrals. Various qualitatively different types of behaviour of these random Dirac operators are exhibited. Some features are explained in terms of the theory of random matrices but other phenomena remain mysterious. Some of the models with a quartic action of symmetry-breaking type display a phase transition. Close to the phase transition the spectrum of a typical Dirac operator shows manifold-like behaviour for the eigenvalues below a cut-off scale.
Logarithmic Sobolev inequalities in non-commutative algebras
NASA Astrophysics Data System (ADS)
Carbone, Raffaella; Martinelli, Andrea
2015-06-01
We study the relations between (tight) logarithmic Sobolev inequalities, entropy decay and spectral gap inequalities for Markov evolutions on von Neumann algebras. We prove that log-Sobolev inequalities (in the non-commutative form defined by Olkiewicz and Zegarlinski in Ref. 25) imply spectral gap inequalities, with optimal relation between the constants. Furthermore, we show that a uniform exponential decay of a proper relative entropy is equivalent to a modified version of log-Sobolev inequalities. The relations among the mentioned inequalities are investigated and often depend on some regularity conditions, which are also discussed. With regard to this aspect, we provide an example of a positive identity-preserving semigroup not verifying the usually requested regularity conditions (which are always fulfilled for reversible classical Markov processes).
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. PMID:25493736
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.
A complete set of commuting operators for the Bethe ansatz
NASA Astrophysics Data System (ADS)
Lulek, T.; Topolewicz, S.
2010-12-01
We have derived an explicit formula for a complete set of commuting operators for the XXX model of the Heisenberg magnetic ring, using an algebraic Bethe ansatz approach of Faddeev and Takhtajan. Each operator turns out to be the sum of increasing l-cycles in the symmetric group acting on the set of nodes of the ring. It is demonstrated that the resulting algebra of operators encloses the total spin S, the Hamiltonian and the quasimomentum. We point out that it is a maximal Abelian subalgebra in the algebra of the symmetric group, associated with the basis of exact Bethe ansatz eigenstates, the latter classified by rigged string configurations of Kerrov, Kirillov and Reshetikhin. This algebra is also conjugated to the Jucys-Murphy algebra, responsible for the Young orthogonal basis of standard tableaux along the Schur-Weyl duality.
Quantum groups, non-commutative differential geometry and applications
Schupp, P
1993-12-09
The topic of this thesis is the development of a versatile and geometrically motivated differential calculus on non-commutative or quantum spaces, providing powerful but easy-to-use mathematical tools for applications in physics and related sciences. A generalization of unitary time evolution is proposed and studied for a simple 2-level system, leading to non-conservation of microscopic entropy, a phenomenon new to quantum mechanics. A Cartan calculus that combines functions, forms, Lie derivatives and inner derivations along general vector fields into one big algebra is constructed for quantum groups and then extended to quantum planes. The construction of a tangent bundle on a quantum group manifold and an BRST type approach to quantum group gauge theory are given as further examples of applications. The material is organized in two parts: Part I studies vector fields on quantum groups, emphasizing Hopf algebraic structures, but also introducing a ``quantum geometric`` construction. Using a generalized semi-direct product construction we combine the dual Hopf algebras A of functions and U of left-invariant vector fields into one fully bicovariant algebra of differential operators. The pure braid group is introduced as the commutant of {Delta}(U). It provides invariant maps A {yields} U and thereby bicovariant vector fields, casimirs and metrics. This construction allows the translation of undeformed matrix expressions into their less obvious quantum algebraic counter parts. We study this in detail for quasitriangular Hopf algebras, giving the determinant and orthogonality relation for the ``reflection`` matrix. Part II considers the additional structures of differential forms and finitely generated quantum Lie algebras -- it is devoted to the construction of the Cartan calculus, based on an undeformed Cartan identity.
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
Determining the intensity and energy expenditure during commuter cycling
de Geus, B; De Smet, S; Nijs, J; Meeusen, R
2007-01-01
Objectives To determine the intensity and energy expenditure during commuter cycling, and to investigate whether cycling to work at a self‐chosen intensity corresponds to recommendations of the Centers for Disease Control and Prevention (CDC) and American College of Sports Medicine (ACSM) for health improvement and ACSM recommendations for fitness improvement. Methods 18 healthy, untrained middle‐aged people, who did not cycle to work, underwent two maximal exercise tests (MT and MT2) in order to measure their maximal heart rate and oxygen consumption (VO2). MT2 was performed 24 weeks after MT. Participants were asked to cycle at least three times a week to their workplace over a one‐way minimum distance of 2 km. Data on cycling were recorded in a diary. 12 weeks after MT, a field test was conducted, where participants had to cycle to or from their workplace. The same measurements were taken as during MT as markers of exercise intensity. Metabolic equivalents (METs) and energy expenditure were calculated. Results The intensity during the field test was >75% of their maximal aerobic capacity. The mean (SD) MET value was 6.8 (1.9). The energy expenditure during the field test was 220 (115) kcal or 540 (139) kcal/h and 1539 (892) kcal/week. Men consumed significantly (p<0.01) more energy per hour than women. Conclusion Commuter cycling at a self‐selected intensity meets the CDC and ACSM recommendations for health improvement and the ACSM recommendations for improvement of cardiorespiratory fitness. However, as the participants cycled faster during the field test than during daily cycling, the results should be interpreted with caution. PMID:17021003
Commutative law for products of infinitely large isotropic random matrices.
Burda, Zdzislaw; Livan, Giacomo; Swiech, Artur
2013-08-01
Ensembles of isotropic random matrices are defined by the invariance of the probability measure under the left (and right) multiplication by an arbitrary unitary matrix. We show that the multiplication of large isotropic random matrices is spectrally commutative and self-averaging in the limit of infinite matrix size N→∞. The notion of spectral commutativity means that the eigenvalue density of a product ABC... of such matrices is independent of the order of matrix multiplication, for example, the matrix ABCD has the same eigenvalue density as ADCB. In turn, the notion of self-averaging means that the product of n independent but identically distributed random matrices, which we symbolically denote by AAA..., has the same eigenvalue density as the corresponding power A(n) of a single matrix drawn from the underlying matrix ensemble. For example, the eigenvalue density of ABCCABC is the same as that of A(2)B(2)C(3). We also discuss the singular behavior of the eigenvalue and singular value densities of isotropic matrices and their products for small eigenvalues λ→0. We show that the singularities at the origin of the eigenvalue density and of the singular value density are in one-to-one correspondence in the limit N→∞: The eigenvalue density of an isotropic random matrix has a power-law singularity at the origin ~|λ|(-s) with a power sε(0,2) when and only when the density of its singular values has a power-law singularity ~λ(-σ) with a power σ=s/(4-s). These results are obtained analytically in the limit N→∞. We supplement these results with numerical simulations for large but finite N and discuss finite-size effects for the most common ensembles of isotropic random matrices. PMID:24032775
Coulomb problem in non-commutative quantum mechanics
Galikova, Veronika; Presnajder, Peter
2013-05-15
The aim of this paper is to find out how it would be possible for space non-commutativity (NC) to alter the quantum mechanics (QM) solution of the Coulomb problem. The NC parameter {lambda} is to be regarded as a measure of the non-commutativity - setting {lambda}= 0 which means a return to the standard quantum mechanics. As the very first step a rotationally invariant NC space R{sub {lambda}}{sup 3}, an analog of the Coulomb problem configuration space (R{sup 3} with the origin excluded) is introduced. R{sub {lambda}}{sup 3} is generated by NC coordinates realized as operators acting in an auxiliary (Fock) space F. The properly weighted Hilbert-Schmidt operators in F form H{sub {lambda}}, a NC analog of the Hilbert space of the wave functions. We will refer to them as 'wave functions' also in the NC case. The definition of a NC analog of the hamiltonian as a hermitian operator in H{sub {lambda}} is one of the key parts of this paper. The resulting problem is exactly solvable. The full solution is provided, including formulas for the bound states for E < 0 and low-energy scattering for E > 0 (both containing NC corrections analytic in {lambda}) and also formulas for high-energy scattering and unexpected bound states at ultra-high energy (both containing NC corrections singular in {lambda}). All the NC contributions to the known QM solutions either vanish or disappear in the limit {lambda}{yields} 0.
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.
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
2014-12-01
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
Photography of the commutation spark using a high-speed camera
NASA Astrophysics Data System (ADS)
Hanazawa, Tamio; Egashira, Torao; Tanaka, Yasuhiro; Egoshi, Jun
1997-12-01
In the single-phase AC commutator motor (known as a universal motor), which is widely used in cleaners, electrical machines, etc., some problems generated by commutation sparks are wear on the brush and noise impediments. We have therefore attempted to use a high-speed camera to elucidate the commutation spark mechanism visually. The high-speed camera that we used is capable of photographing at 5,000 - 20,000,000 frames/s. Selection of a trigger module can be obtained from the operation unit and the exterior triggering signal. In this paper, we proposed an exterior trigger method that involved opening a hole of several millimeters across in the motor and using argon laser light, so that commutator segments may be photographed in position; we then conducted the experiment. This method enabled us to photograph the motor's commutator segment from any position, and we were able to confirm spark generation at every other commutator segment. Furthermore, after confirming the spark generation position of the commutator segment, we next attempted to accelerate the photographing speed to obtain more detailed photography of the moment of spark generation; we then prepared our report.
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
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
2014-05-01
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
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
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.
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.
Stability of switched linear discrete-time descriptor systems: a new commutation condition
NASA Astrophysics Data System (ADS)
Zhai, Guisheng; Xu, Xuping; Ho, Daniel W. C.
2012-11-01
In this article, we study stability of switched linear discrete-time descriptor systems. Under the assumption that all subsystems are stable and there is no impulse occurring at the switching instants, we establish a new pairwise commutation condition under which the switched system is stable. It turns out that the condition is a natural and important extension to the existing commutation conditions, and it can be applied in discretised continuous-time switched systems in a straightforward manner. Finally, we also show that when the proposed commutation condition holds, there exists a common quadratic Lyapunov function for the subsystems.
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
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.
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.
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. PMID:10081238
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.
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.
Cubical homology and the Leech dimension of free partially commutative monoids
NASA Astrophysics Data System (ADS)
Khusainov, Akhmet A.
2008-12-01
The paper is devoted to problems arising when applying homological algebra to computer science. It is proved that the Leech dimension of a free partially commutative monoid is equal to the least upper bound of the cardinalities of finite subsets of pairwise commuting generators of the monoid. For an arbitrary free partially commutative monoid M(E,I) in which every subset of pairwise commuting generators is finite and for any contravariant natural system F on M(E,I) we construct a semicubical set T(E,I) with a homological system \\overline F on this set such that the Leech homology groups H_n(M(E,I),F) are isomorphic to the cubical homology groups H_n(T(E,I),\\overline F). Complexes of Abelian groups are also constructed enabling one to obtain (under additional finiteness conditions) algorithms for computing the Leech homology groups and homology groups with coefficients in right M(E,I)-modules. Bibliography: 16 titles.
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...
77 FR 43135 - Application of City Wings, Inc. D/B/A Seaflight for Commuter Authority
Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-23
... directing all interested persons to show cause why it should not issue an order finding City Wings, Inc. d/b/a Seaflight fit, willing, and able, and awarding it Commuter Air Carrier Authorization....
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...
Commutation of Projections and Characterization of Traces on von Neumann Algebras. III
NASA Astrophysics Data System (ADS)
Bikchentaev, A. M.
2015-12-01
We obtain new necessary and sufficient commutation conditions for nonnegative operators and projections in terms of operator inequalities. It is shown that in the general case in this inequalities the projections cannot be replaced by arbitrary nonnegative operators with preservation of operators commutativity. We also present new necessary and sufficient commutation conditions for projections in terms of operator inequalities. These inequalities are applied for trace characterization on von Neumann algebras in the class of all positive normal functionals. We also consider the following problems: I. Characterization of traces among arbitrary weights on von Neumann algebras. II. Characterization of tracial functionals among all positive linear functionals on C ∗-algebras. III. Characterization of commutativity for C ∗-algebras.
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.
Quantum Groups, Non-Commutative Differential Geometry and Applications
NASA Astrophysics Data System (ADS)
Schupp, Peter
The topic of this thesis is the development of a versatile and geometrically motivated differential calculus on non-commutative or quantum spaces, providing powerful but easy-to-use mathematical tools for applications in physics and related sciences. A generalization of unitary time evolution is proposed and studied for a simple 2-level system, leading to non-conservation of microscopic entropy, a phenomenon new to quantum mechanics. A Cartan calculus that combines functions, forms, Lie derivatives and inner derivations along general vector fields into one big algebra is constructed for quantum groups and then extended to quantum planes. The construction of a tangent bundle on a quantum group manifold and an BRST type approach to quantum group gauge theory are given as further examples of applications. The material is organized in two parts: Part I studies vector fields on quantum groups, emphasizing Hopf algebraic structures, but also introducing a 'quantum geometric' construction. Using a generalized semi-direct product construction we combine the dual Hopf algebras {cal A} of functions and {cal U} of left-invariant vector fields into one fully bicovariant algebra of differential operators. The pure braid group is introduced as the commutant of Delta({cal U}). It provides invariant maps {cal A} to{cal U} and thereby bicovariant vector fields, casimirs and metrics. This construction allows the translation of undeformed matrix expressions into their less obvious quantum algebraic counter parts. We study this in detail for quasitriangular Hopf algebras, giving the determinant and orthogonality relation for the 'reflection' matrix. Part II considers the additional structures of differential forms and finitely generated quantum Lie algebras--it is devoted to the construction of the Cartan calculus, based on an undeformed Cartan identity. We attempt a classification of various types of quantum Lie algebras and present a fairly general example for their construction
Exposure to traffic pollution, acute inflammation and autonomic response in a panel of car commuters
Sarnat, Jeremy A.; Golan, Rachel; Greenwald, Roby; Raysoni, Amit U.; Kewada, Priya; Winquist, Andrea; Sarnat, Stefanie E.; Flanders, W. Dana; Mirabelli, Maria C.; Zora, Jennifer E.; Bergin, Michael H.; Yip, Fuyuen
2015-01-01
Background Exposure to traffic pollution has been linked to numerous adverse health endpoints. Despite this, limited data examining traffic exposures during realistic commutes and acute response exists. Objectives: We conducted the Atlanta Commuters Exposures (ACE-1) Study, an extensive panel-based exposure and health study, to measure chemically-resolved in-vehicle exposures and corresponding changes in acute oxidative stress, lipid peroxidation, pulmonary and systemic inflammation and autonomic response. Methods We recruited 42 adults (21 with and 21 without asthma) to conduct two 2-h scripted highway commutes during morning rush hour in the metropolitan Atlanta area. A suite of in-vehicle particulate components were measured in the subjects’ private vehicles. Biomarker measurements were conducted before, during, and immediately after the commutes and in 3 hourly intervals after commutes. Results At measurement time points within 3 h after the commute, we observed mild to pronounced elevations relative to baseline in exhaled nitric oxide, C-reactive-protein, and exhaled malondialdehyde, indicative of pulmonary and systemic inflammation and oxidative stress initiation, as well as decreases relative to baseline levels in the time-domain heart-rate variability parameters, SDNN and rMSSD, indicative of autonomic dysfunction. We did not observe any detectable changes in lung function measurements (FEV1, FVC), the frequency-domain heart-rate variability parameter or other systemic biomarkers of vascular injury. Water soluble organic carbon was associated with changes in eNO at all post-commute time-points (p < 0.0001). Conclusions Our results point to measureable changes in pulmonary and autonomic biomarkers following a scripted 2-h highway commute. PMID:24906070
Ohtsuka, R; Umezaki, M
1993-06-01
Census data was analyzed for 20 municipalities along the Tohoku Line in Tokyo Megalopolis to elucidate the changes in the population structure and the commuting situation in the last two decades. The major findings were: (1) the changing pattern of population structure markedly varied among the municipalities, and (2) the long-distance commuting workers have increased particularly among those 50 km or more from central Tokyo. PMID:8064153
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.
Dead time analysis of inductor commutation dc-to-dc converter controlled by a small saturable core
NASA Astrophysics Data System (ADS)
Harada, Kazurou; Sakamoto, Hiroshi; Harada, Koosuke
1990-09-01
A novel method of high-frequency switching for dc-to-dc converters is presented. This method is based on the commutation with the aid of inductor current, where a short interval (dead time) of both switches off is given for removing switching surges and switching losses. By the method of constant current-ripple using a saturable core, the condition of zero voltage switching is made independent of the duty ratio. The output voltage is regulated by pulse width modulation in the same way as that of the conventional converter of PWM control. From calculations and experiments, it is found that a desired dead time is derived by connecting external capacitance to the gate-source terminal of the MOSFET.
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.
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.
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.
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
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.
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
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. PMID:24512572
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).
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.
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
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.
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.
Etude D'onduleurs Triphases a Haute Frequence et a Commutation Douce
NASA Astrophysics Data System (ADS)
Cheriti, Ahmed
This thesis contributes to the increase of the application field of resonant converters which until now was limited to small switch mode power supplies. The approaches used in this case cannot be straight forward applied to the inverters which operate in several quadrants and where the power involved is much higher. Therefore, the integration of the resonance techniques to the inverters necessitates a separate study and that is what we are trying to do in this work. The configuration that we wanted to develop should have two major features. Firstly, it should not generate any overvoltage on the power semiconductors. Secondly, it should be able to operate in pulse width modulation at high frequency. Consequently an approach such as the recently proposed resonant dc link inverter will not be considered. After analysing a few structures, we selected a configuration which met our specifications. This configuration was called: the pulse width Modulation Resonant Pole Inverter (MRPI) and it will the subject for a detailed study in this thesis. Basically, this study includes: the applications, the operating sequences, the design, the possible modifications, the base drive circuits, the control circuit, the experimentation and the efficiency calculations. In this study, the state-plane technique is extensively used. This technique simplifies the study of second order systems with low damping factor. For example, we use the state plane while determining: (1) the operating sequences and their duration, (2) the voltage and current stresses on the power semiconductors, (3) the operating limits. The experimental tests were held on a three-phase asynchronous machine based variable speed drive controlled under the V/F constant low. The control circuit implementing this law was elaborated with the help of original digital circuits which will be the subject for a detailed description too. Finally, we will show in this thesis that the proposed configuration contributes substantially
Spacetime Non-Commutativity Corrections to the Cardy-Verlinde Formula of Achúcarro-Ortiz Black Hole
NASA Astrophysics Data System (ADS)
Setare, M. R.
2007-02-01
In this letter we compute the corrections to the Cardy-Verlinde formula of Achúcarro-Ortiz black hole, which is the most general two-dimensional black hole derived from the three-dimensional rotating Banados-Teitelboim-Zanelli black hole. These corrections stem from the space non-commutativity. We show that in non-commutative case, non-rotating Achúcarro-Ortiz black hole in contrast with commutative case has two horizons.
NASA Astrophysics Data System (ADS)
Varshovi, Amir Abbass
2013-07-01
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.
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
Kumar, Pramod; Gupta, N C
2016-01-15
A public health concern is to understand the linkages between specific pollution sources and adverse health impacts. Commuting can be viewed as one of the significant-exposure activity in high-vehicle density areas. This paper investigates the commuter exposure to inhalable, thoracic and alveolic particles in various transportation modes in Delhi, India. Air pollution levels are significantly contributed by automobile exhaust and also in-vehicle exposure can be higher sometime than ambient levels. Motorcycle, auto rickshaw, car and bus were selected to study particles concentration along two routes in Delhi between Kashmere Gate and Dwarka. The bus and auto rickshaw were running on compressed natural gas (CNG) while the car and motorcycle were operated on gasoline fuel. Aerosol spectrometer was employed to measure inhalable, thoracic and alveolic particles during morning and evening rush hours for five weekdays. From the study, we observed that the concentration levels of these particles were greatly influenced by transportation modes. Concentrations of inhalable particles were found higher during morning in auto rickshaw (332.81 ± 90.97 μg/m(3)) while the commuter of bus exhibited higher exposure of thoracic particles (292.23 ± 110.45 μg/m(3)) and car commuters were exposed to maximum concentrations of alveolic particles (222.37 ± 26.56 μg/m(3)). We observed that in evening car commuters experienced maximum concentrations of all sizes of particles among the four commuting modes. Interestingly, motorcycle commuters were exposed to lower levels of inhalable and thoracic particles during morning and evening hours as compared to other modes of transport. The mean values were found greater than the median values for all the modes of transport suggesting that positive skewed distributions are characteristics of naturally occurring phenomenon. PMID:26439646
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.
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.
Aspects of non-commutative gauge theory and the AdS/CFT correspondance
NASA Astrophysics Data System (ADS)
Thomas, Keith S.
Non-commutative gauge theory with a non-constant non-commutativity parameter can be formulated as a decoupling limit of open strings ending on D3-branes wrapping a Melvin universe. We identify this model as a simple Melvin twist of flat D3 branes. Along similar lines, one recognizes the model of Hashimoto and Sethi as being the Melvin null twist, and the model of Dolan and Nappi as being the null Melvin twist, of the flat D3-brane. This construction therefore offers a unified perspective on most of the known explicit constructions of non-commutative gauge theories as a decoupled theory of D-branes in a, B-field background. In order to gain insight into the type of physics embodied in such theories, we describe the world volume theory on a D3-brane embedded in a Melvin universe which is decaying via the nucleation of monopole anti-monopole pairs. Further, focusing on the gauge theory properties and dynamics, we construct the action explicitly for the Melvin twist non-commutative gauge theory and discuss various physical features of the model. The decoupled field theory is not supersymmetric. Nonetheless, the Coulomb branch appears to remain flat at least in the large N and large 't Hooft coupling limit. We also find the analogue of Prasad-Sommerfield monopoles whose size scales with the non-commutativity parameter and is therefore position dependent.
Differential commuting operator and closed-form eigenfunctions for linear canonical transforms.
Pei, Soo-Chang; Liu, Chun-Lin
2013-10-01
The linear canonical transform (LCT) with a, b, c, d parameter plays an important role in quantum mechanics, optics, and signal processing. The eigenfunctions of the LCT are also important because they describe the self-imaging phenomenon in optical systems. However, the existing solutions for the eigenfunctions of the LCT are divided into many cases and they lack a systematic way to solve these eigenfunctions. In this paper, we find a linear, second-order, self-adjoint differential commuting operator that commutes with the LCT operator. Hence, the commuting operator and the LCT share the same eigenfunctions with different eigenvalues. The commuting operator is very general and simple when it is compared to the existing multiple-parameter differential equations. Then, the eigenfunctions can be derived systematically. The eigenvalues of the commuting operator have closed-form relationships with the eigenvalues of the LCT. We also simplify the eigenfunctions for |a+d|>2 and a+d=±2, b≠0 into the more compact closed form instead of the integral form. For |a+d|>2, the eigenfunctions are related to the parabolic cylinder functions. PMID:24322865
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.
Dualities, Twists, and Gauge Theories with Non-Constant Non-Commutativity
NASA Astrophysics Data System (ADS)
Hashimoto, Akikazu
2005-01-01
We study the world volume theory of D3-branes wrapping the Melvin universe supported by background NSNS B-field. In the appropriate decoupling limit, the open string dynamics is that of non-commutative guage field theory with non-constant non-commutativity. We identify this model as a simple Melvin twist of flat D3 branes. Along similar lines, one recognizes the model of Hashimoto and Sethi as being the Melvin null twist, and the model of Dolan and Nappi as being the null Melvin twist, of the flat D3-brane. This construction therefore offers a unified perspective on most of the known explicit constructions of non-commutative gauge theories as a decoupled theory of D-branes in a B-field background. We also describe the world volume theory on the D3-brane in a Melvin universe which is decaying via the nucleation of monopole anti-monopole pair.
Non-Commutative Integration, Zeta Functions and the Haar State for SU q (2)
NASA Astrophysics Data System (ADS)
Matassa, Marco
2015-12-01
We study a notion of non-commutative integration, in the spirit of modular spectral triples, for the quantum group SU q (2). In particular we define the non-commutative integral as the residue at the spectral dimension of a zeta function, which is constructed using a Dirac operator and a weight. We consider the Dirac operator introduced by Kaad and Senior and a family of weights depending on two parameters, which are related to the diagonal automorphisms of SU q (2). We show that, after fixing one of the parameters, the non-commutative integral coincides with the Haar state of SU q (2). Moreover we can impose an additional condition on the zeta function, which also fixes the second parameter. For this unique choice the spectral dimension coincides with the classical dimension.
Two Phases of the Non-Commutative Quantum Mechanics with the Generalized Uncertainty Relations
NASA Astrophysics Data System (ADS)
Chung, Won Sang
2016-04-01
We consider the quantum mechanics on the noncommutative plane with the generalized uncertainty relations {Δ } x1 {Δ } x2 ge frac {θ }{2}, {Δ } p1 {Δ } p2 ge frac {bar {θ }}{2}, {Δ } xi {Δ } pi ge frac {hbar }{2}, {Δ } x1 {Δ } p2 ge frac {η }{2}. We show that the model has two essentially different phases which is determined by kappa = 1 + frac {1}{hbar 2 } (η 2 - θ bar {θ }). We construct a operator hat {π }i commuting with hat {x}j and discuss the harmonic oscillator model in two dimensional non-commutative space for three case κ > 0, κ = 0, κ < 0. Finally, we discuss the thermodynamics of a particle whose hamiltonian is related to the harmonic oscillator model in two dimensional non-commutative space.
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. PMID:27018939
Commutative n-ary superalgebras with an invariant skew-symmetric form
NASA Astrophysics Data System (ADS)
Vishnyakova, E. G.
2015-12-01
We study n-ary commutative superalgebras and L∞-algebras that possess a skew-symmetric invariant form, using the derived bracket formalism. This class of superalgebras includes for instance Lie algebras and their n-ary generalizations, commutative associative and Jordan algebras with an invariant form. We give a classification of anti-commutative m-dimensional (m - 3) -ary algebras with an invariant form, and a classification of real simple m-dimensional Lie (m - 3) -algebras with a positive definite invariant form up to isometry. Furthermore, we develop the Hodge Theory for L∞-algebras with a symmetric invariant form, and we describe quasi-Frobenius structures on skew-symmetric n-ary algebras.
Ecological Analysis of Parking Prices and Active Commuting in US Cities, 2009.
Whitfield, Geoffrey P; Wendel, Arthur M; Auchincloss, Amy H
2016-01-01
We conducted an ecological study to determine whether parking prices are associated with active commuting across US cities. We obtained parking prices for 107 US cities from the Drexel University Central Business District Public Parking Survey, obtained city prevalence of walking and bicycling to work from the American Community Survey, and used weighted least squares linear regression to explore associations between parking prices and active commuting. After adjusting for several covariates, walking to work was 3.1% higher for every additional dollar charged for off-street daily parking, but only among more densely populated cities, and no such association was detected for bicycling to work. These preliminary results hint at the potential for parking policies to influence commuting mode choice, a link that city planners and public health officials could consider when evaluating parking policies and active transportation behaviors. PMID:27609301
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.
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.
Wigner function for Klein-Gordon oscillator in commutative and noncommutative spaces
NASA Astrophysics Data System (ADS)
Hassanabadi, S.; Ghominejad, M.
2016-06-01
As a quasi-probability distribution function in phase-space and a special representation of the density matrix, the Wigner function is of great significance in physics. In this work, the Wigner function for the Klein-Gordon oscillator is studied in commutative and noncommutative spaces. We first study the Wigner function for Klein-Gordon oscillator in commutative space then, by using a generalized Bopp's shift method, we obtain the corresponding Wigner function in noncommutative space. The additional terms in Wigner function on a NC space is related to the noncommutativity of space.
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
Extended and internal commuting in the transformation of the intermetropolitian periphery.
Fisher, J S; Mitchelson, R L
1981-07-01
This paper assesses the roles played by extended and internal commuting in urbanizing the intermetropolitan periphery by studying 4 standard metropolitan statistical areas (SMSAs) in northeast Georgia (GA) and adjacent South Carolina (SC). Extended commuting is worker movements across county boundaries from nonmetropolitan areas to metropolitan areas. Internal commuting is worker movements such that origin and destination counties both lie within the intermetropolitan periphery. In the US, nonmetropolitan population growth rates now exceed those of metropolitan areas. 2 frequent interpretations of this trend are that nonmetropolitan growth is 1) decentralized resulting from metropolitan spread and 2) partially independent of metropolitian influence. The study uses commuting destinations from the 4 SMSAs (Atlanta, Macon, and Augusta, GA, and Greenville, SC), their respective central cities, and selected internal or intervening opportunity centers within the intermetropolitan periphery. Extended commuting fields were identified for both 1960 and 1970 using 0, 5, and 10% isolines; this paper only includes 0 and 5% isolines. There is an modest expansion of the 5% lines by 1970 for each region, indicating the extension of metropolitan influence. Growth is most apparent in larger centers such as Gainseville, Athens, and Conyers. By 1970, the 5% isolines show extreme cases of overlapping commuting fields. Residents of such zones interact significantly with more than 1 center; therefore, urbanization of the intermetropolitan area occurs both in response to metropolitan spread and the internal growth processes extending the influence of internal centers. Population growth within this nonmetropolitan area is linked to metropolitan center expansion and commuting to smaller internal growth centers plays an equally important role. 76% of county divisions within 15 miles of a metropolitan or internal growth center and 48% at distances of 15-35 miles experienced population
Code of Federal Regulations, 2014 CFR
2014-10-01
... CFR 38.95(c) and 38.125(c). ... Intercity, Commuter, and High-Speed Rail Station Platforms Constructed or Altered After February 1, 2012. 37... Passengers at Intercity, Commuter, and High-Speed Rail Station Platforms Constructed or Altered...
Code of Federal Regulations, 2012 CFR
2012-10-01
... CFR 38.95(c) and 38.125(c). ... Intercity, Commuter, and High-Speed Rail Station Platforms Constructed or Altered After February 1, 2012. 37... Passengers at Intercity, Commuter, and High-Speed Rail Station Platforms Constructed or Altered...
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...
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... Airways, Inc. d/b/a Yellow Air Taxi and deny its application to resume commuter operations, pursuant to...
Code of Federal Regulations, 2011 CFR
2011-01-01
... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal,...
Code of Federal Regulations, 2012 CFR
2012-01-01
... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal,...
Code of Federal Regulations, 2013 CFR
2013-01-01
... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal,...
Code of Federal Regulations, 2014 CFR
2014-01-01
... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal,...
Code of Federal Regulations, 2013 CFR
2013-10-01
... CFR 38.95(c) and 38.125(c). ... Intercity, Commuter, and High-Speed Rail Station Platforms Constructed or Altered After February 1, 2012. 37... Passengers at Intercity, Commuter, and High-Speed Rail Station Platforms Constructed or Altered...
Code of Federal Regulations, 2010 CFR
2010-01-01
... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal,...
Code of Federal Regulations, 2011 CFR
2011-10-01
... CFR 38.95(c) and 38.125(c). Effective Date Note: At 76 FR 57935, Sept. 19, 2011, § 37.42 was added... intercity, commuter, and high-speed rail station platforms constructed or altered after February 1, 2012. 37... passengers at intercity, commuter, and high-speed rail station platforms constructed or altered...
"I Am More Productive in the Library Because It's Quiet": Commuter Students in the College Library
ERIC Educational Resources Information Center
Regalado, Mariana; Smale, Maura A.
2015-01-01
This article discusses commuter students' experiences with the academic library, drawn from a qualitative study at the City University of New York. Undergraduates at six community and baccalaureate colleges were interviewed to explore how they fit schoolwork into their days, and the challenges and opportunities they encountered. Students…
14 CFR 330.27 - What information must certificated and commuter air carriers submit?
Code of Federal Regulations, 2010 CFR
2010-01-01
... proceeds from business recovery insurance or other insurance payments. You must not report as losses... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false What information must certificated and commuter air carriers submit? 330.27 Section 330.27 Aeronautics and Space OFFICE OF THE...
Who Needs to Do What Where?: Using Learning Management Systems on Residential vs. Commuter Campuses
ERIC Educational Resources Information Center
Lonn, Steven; Teasley, Stephanie D.; Krumm, Andrew E.
2011-01-01
Learning Management Systems (LMS) are web-based systems allowing instructors and/or students to share materials and interact online. This study compared differences in LMS use between instructors and students at a large residential campus with students at a smaller commuter campus. Responses to an online survey about LMS activities and tools were…
The Relationship Between Self-Concept and Marital Adjustment for Commuter College Students
ERIC Educational Resources Information Center
Hall, William M.; Valine, Warren J.
1977-01-01
An investigation was made of the relationship between self-concept and the adjustment of commuter college students. Instruments used were the Tennessee Self Concept Scale and the Locke-Wallace Marital Adjustment Test. There was a significant relationship between self-concept and marital adjustment. (Author)
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,
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... procedures and regulations to effect a prohibition of on-street parking within Boston proper between...
75 FR 69734 - Application of Island Airlines, LLC for Commuter Air Carrier Authorization
Federal Register 2010, 2011, 2012, 2013, 2014
2010-11-15
... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Island Airlines, LLC for Commuter Air Carrier Authorization AGENCY... it should not issue an order finding Island Airlines, LLC, fit, willing, and able, and awarding...
49 CFR 37.87 - Purchase or lease of used intercity and commuter rail cars.
Code of Federal Regulations, 2012 CFR
2012-10-01
... rail cars. 37.87 Section 37.87 Transportation Office of the Secretary of Transportation TRANSPORTATION....87 Purchase or lease of used intercity and commuter rail cars. (a) Except as provided elsewhere in... car after August 25, 1990, shall ensure that the car is readily accessible to and usable...
49 CFR 37.87 - Purchase or lease of used intercity and commuter rail cars.
Code of Federal Regulations, 2013 CFR
2013-10-01
... rail cars. 37.87 Section 37.87 Transportation Office of the Secretary of Transportation TRANSPORTATION....87 Purchase or lease of used intercity and commuter rail cars. (a) Except as provided elsewhere in... car after August 25, 1990, shall ensure that the car is readily accessible to and usable...
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
14 CFR 135.398 - Commuter category airplanes performance operating limitations.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Commuter category airplanes performance operating limitations. 135.398 Section 135.398 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS OPERATING...
Non-commuting two-local Hamiltonians for quantum error suppression
NASA Astrophysics Data System (ADS)
Rieffel, Eleanor; Jiang, Zhang; QuAIL Team
Physical constraints make it challenging to implement and control multi-body interactions. Designing quantum information processes with Hamiltonians consisting of only one- and two-local terms is a worthwhile challenge. A common approach to robust storage of quantum information is to encode in the ground subspace of a Hamiltonian. Even allowing particles with high Hilbert-space dimension, it is not possible to protect quantum information from single-site errors by encoding in the ground subspace of any Hamiltonian containing only commuting two-local terms. We demonstrate how to get around this no-go result by encoding in the ground subspace of a Hamiltonian consisting of non-commuting two-local terms arising from the gauge operators of a subsystem code. Specifically, we show how to protect stored quantum information against single-qubit errors using a Hamiltonian consisting of sums of the gauge generators from Bacon-Shor codes and generalized-Bacon-Shor code. Thus, non-commuting two-local Hamiltonians have more error-suppressing power than commuting two-local Hamiltonians. Finally, we comment briefly on the robustness of the whole scheme.
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.…
Active commuting to school and association with physical activity and weight among US youth
Technology Transfer Automated Retrieval System (TEKTRAN)
Studies have reported inconsistent findings for the relationship between active commuting to school (ACS) and physical activity or weight status/adiposity among youth. These mixed findings may be due to reliance on self-report measures of physical activity, samples drawn from specific populations, i...
Picturing commuting: photovoice and seeking well-being in everyday travel
Ogilvie, David
2015-01-01
We used participant-produced photography to investigate everyday commuting practices in Cambridge, UK. Photovoice served as an observational method for producing ethnographically rich data. A total of 19 participants produced over 500 photos about their journeys to and from work and took part in photo-elicitation interviews. Three themes emerged. First, many images depicted ‘well-being’ in commuting, for example, beautiful landscapes. Second, during elicitation interviews, participants described positive images that they intended but failed to capture in photos. Third, those participants who did not depict well-being described a lack of choice in their commuting, while those who acknowledged well-being seemed to do so in order to make practices of commuting meaningful and habitable. While our interpretations of photos of well-being could be subject to a methodological fallacy relating to a preference for positive over negative images in lay photography, we nonetheless suggest that the rich visual and oral narratives indicate a ‘real’ experience, albeit elicited through the photovoice. PMID:25972763
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…
Merchant Marine and Commuter Families: A Comparison of Couples Who Live Apart.
ERIC Educational Resources Information Center
Gross, Harriet Engel; And Others
A study compared commuter and Merchant Marine families with traditional households in order to separate effects related to living apart from those related to the career status (single vs. dual) of families. During the study researchers conducted in-depth interviews with 50 wives and 30 husbands representing 58 Merchant Marine families of whom 22…
Student Recreation: A Comparison of Commuter and Resident Students. Research Report No. 4-77.
ERIC Educational Resources Information Center
Foster, Margaret E.; And Others
Information about the needs, interests, and use of recreational facilities was obtained from 407 undergraduate students from the University of Maryland. Responses to a 15-item telephone survey were received from 90 percent of a stratified, random sample of 450 students. There were 154 residents, 160 dependent commuters, and 93 independent…
Active commuting to school and association with physical activity and adiposity among US youth
Technology Transfer Automated Retrieval System (TEKTRAN)
Walking or bicycling to school, i.e., "active commuting", was associated with greater physical activity and lower adiposity. However, findings were mixed and may be due to small sample sizes, subjectively measured physical activity, or not controlling for dietary energy intake. Our objective was to ...
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...
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,...
40 CFR 52.1161 - Incentives for reduction in single-passenger commuter vehicle use.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Incentives for reduction in single-passenger commuter vehicle use. 52.1161 Section 52.1161 Protection of Environment ENVIRONMENTAL PROTECTION... live at the educational institution and who travels to and from classes by any mode of travel....
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…
Technology Transfer Automated Retrieval System (TEKTRAN)
Walking School Buses (WSB) are groups of students, led to and from school by adults, in which students are picked up at designated "bus stops". The impact of WSB programs on students' active commuting to school (walking/cycling to school, ACS), and moderate-to vigorous-physical activity (MVPA) has n...
Description of a small commutation spike filter for d. c. magnet power supplies
Visser, A.T.
1990-10-01
This note describes a small spike filter used to remove SCR commutation spikes from the dc output voltage of magnet power supplies. Removal of these spikes reduces the noise problems in electronic detectors installed in the same area. The filter is small enough to be mounted inside a power supply.
Rural Industrial Development and Commuting Patterns. Working Paper RID 73.15.
ERIC Educational Resources Information Center
Clemente, Frank; Summers, Gene F.
Information on the commuting patterns of the employees of a recently constructed manufacturing facility in north central Illinois is presented in this report. The subjects included 720 hourly workers and 300 salaried employees of a cold rolling mill. Data were obtained from the 1972 personnel records of the plant and were available for 98% of the…
49 CFR 37.87 - Purchase or lease of used intercity and commuter rail cars.
Code of Federal Regulations, 2011 CFR
2011-10-01
... rail cars. 37.87 Section 37.87 Transportation Office of the Secretary of Transportation TRANSPORTATION....87 Purchase or lease of used intercity and commuter rail cars. (a) Except as provided elsewhere in... car after August 25, 1990, shall ensure that the car is readily accessible to and usable...
Parent, psycho-social, and household factors associated with children's active commuting to school
Technology Transfer Automated Retrieval System (TEKTRAN)
Active commuting to school (ACS), i.e. walking or cycling to school, has been associated with higher levels of physical activity. Few studies have examined children's ACS using the framework of behavior change theory. This study used social cognitive theory as the framework. To examine the relations...
A Study of Commuting Costs at Seven Illinois Public Community Colleges.
ERIC Educational Resources Information Center
Illinois Community Coll. Board, Springfield.
In 1981, a study of the costs to students of commuting to community colleges in Illinois was conducted as an aid to analyzing student financial need policies, to helping students make informed decisions about college attendance, and to analyzing tuition policies related to student costs. A survey instrument was administered to 2,847 students from…
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-27
... Federal Aviation Administration Public Meeting on Future Policy and Rulemaking for Normal, Utility, Acrobatic, and Commuter Category Small Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... discuss a review of the requirements for small airplanes. This discussion focuses on the future of...
Technology Transfer Automated Retrieval System (TEKTRAN)
Active commuting to school (ACS), i.e. walking or cycling to school, has been proposed as a method to increase physical activity. Few studies have examined children's ACS using the framework of behavior change theory. This study used social cognitive theory as the framework. The objective of this st...
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…
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...
14 CFR 204.3 - Applicants for new certificate or commuter air carrier authority.
Code of Federal Regulations, 2011 CFR
2011-01-01
... Transportation Safety Board Regulations, 49 CFR 830.2) experienced by the applicant, its personnel, or any... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Applicants for new certificate or commuter air carrier authority. 204.3 Section 204.3 Aeronautics and Space OFFICE OF THE SECRETARY,...
14 CFR 204.3 - Applicants for new certificate or commuter air carrier authority.
Code of Federal Regulations, 2012 CFR
2012-01-01
... Transportation Safety Board Regulations, 49 CFR 830.2) experienced by the applicant, its personnel, or any... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Applicants for new certificate or commuter air carrier authority. 204.3 Section 204.3 Aeronautics and Space OFFICE OF THE SECRETARY,...
14 CFR 204.3 - Applicants for new certificate or commuter air carrier authority.
Code of Federal Regulations, 2013 CFR
2013-01-01
... Transportation Safety Board Regulations, 49 CFR 830.2) experienced by the applicant, its personnel, or any... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Applicants for new certificate or commuter air carrier authority. 204.3 Section 204.3 Aeronautics and Space OFFICE OF THE SECRETARY,...
78 FR 72746 - Application of Corporate Flight Management, Inc., for Commuter Authority
Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-03
... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Corporate Flight Management, Inc., for Commuter Authority AGENCY... why it should not issue an order finding Corporate Flight Management, Inc., fit, willing, and...
Probability distribution of the index in gauge theory on 2d non-commutative geometry
NASA Astrophysics Data System (ADS)
Aoki, Hajime; Nishimura, Jun; Susaki, Yoshiaki
2007-10-01
We investigate the effects of non-commutative geometry on the topological aspects of gauge theory using a non-perturbative formulation based on the twisted reduced model. The configuration space is decomposed into topological sectors labeled by the index ν of the overlap Dirac operator satisfying the Ginsparg-Wilson relation. We study the probability distribution of ν by Monte Carlo simulation of the U(1) gauge theory on 2d non-commutative space with periodic boundary conditions. In general the distribution is asymmetric under ν mapsto -ν, reflecting the parity violation due to non-commutative geometry. In the continuum and infinite-volume limits, however, the distribution turns out to be dominated by the topologically trivial sector. This conclusion is consistent with the instanton calculus in the continuum theory. However, it is in striking contrast to the known results in the commutative case obtained from lattice simulation, where the distribution is Gaussian in a finite volume, but the width diverges in the infinite-volume limit. We also calculate the average action in each topological sector, and provide deeper understanding of the observed phenomenon.
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…
Fermionic Tunneling Effect and Hawking Radiation in a Non Commutative FRW Universe
NASA Astrophysics Data System (ADS)
Bouhalouf, H.; Mebarki, N.; Aissaoui, H.
2010-10-01
The formalism of a non commutative gauge gravity is applied to an FRW universe and the corresponding modified metric, veirbein and spin connection components are obtained. Moreover, using the Hamilton-Jacobi method and as a pure space-time deformation effect, the NCG Hawking radiation via a fermionic tunneling transition through the dynamical NCG horizon is also studied.
77 FR 45715 - Application of Key Lime Air Corporation for Commuter Authority
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-01
... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Key Lime Air Corporation for Commuter Authority AGENCY: Department... not issue an order finding Key Lime Air Corporation fit, willing, and able, and awarding it a...
Sequential measurements of non-commuting observables with quantum controlled interactions
NASA Astrophysics Data System (ADS)
Hofmann, Holger F.
2014-06-01
The origin of non-classical correlations is difficult to identify since the uncertainty principle requires that information obtained about one observable invariably results in the disturbance of any other non-commuting observable. Here, this problem is addressed by investigating the uncertainty trade-off between measurement errors and disturbance for measurement interactions controlled by the state of a single qubit, where the measurement is described by a quantum coherent superposition of a fully projective measurement and the identity operation. It is shown that the measurement statistics obtained from a quantum controlled measurement of \\hat{A} followed by a projective measurement of \\hat{B} can be explained in terms of a simple combination of resolution and back-action errors acting on an intrinsic joint probability of the non-commuting observables defined by the input state of the system. These intrinsic joint probabilities are consistent with the complex-valued joint probabilities recently observed in weak measurements of quantum systems and provide direct evidence of non-commutativity in the form of imaginary correlations between the non-commuting operators. In quantum controlled measurements, these imaginary correlations can be converted into well-defined contributions to the real measurement statistics, allowing a direct experimental observation of the less intuitive aspects of quantum theory.
14 CFR 23.574 - Metallic damage tolerance and fatigue evaluation of commuter category airplanes.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Metallic damage tolerance and fatigue... COMMUTER CATEGORY AIRPLANES Structure Fatigue Evaluation § 23.574 Metallic damage tolerance and fatigue... evaluation of the strength, detail design, and fabrication must show that catastrophic failure due to...
14 CFR 23.574 - Metallic damage tolerance and fatigue evaluation of commuter category airplanes.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Metallic damage tolerance and fatigue... COMMUTER CATEGORY AIRPLANES Structure Fatigue Evaluation § 23.574 Metallic damage tolerance and fatigue... evaluation of the strength, detail design, and fabrication must show that catastrophic failure due to...
14 CFR 23.574 - Metallic damage tolerance and fatigue evaluation of commuter category airplanes.
Code of Federal Regulations, 2011 CFR
2011-01-01
... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Metallic damage tolerance and fatigue... COMMUTER CATEGORY AIRPLANES Structure Fatigue Evaluation § 23.574 Metallic damage tolerance and fatigue... evaluation of the strength, detail design, and fabrication must show that catastrophic failure due to...
14 CFR 23.574 - Metallic damage tolerance and fatigue evaluation of commuter category airplanes.
Code of Federal Regulations, 2014 CFR
2014-01-01
... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Metallic damage tolerance and fatigue... COMMUTER CATEGORY AIRPLANES Structure Fatigue Evaluation § 23.574 Metallic damage tolerance and fatigue... evaluation of the strength, detail design, and fabrication must show that catastrophic failure due to...
α∗-cohomology, and classification of translation-invariant non-commutative quantum field theories
NASA Astrophysics Data System (ADS)
Varshovi, Amir Abbass
2014-09-01
Translation-invariant ⋆ products are studied in the setting of α∗-cohomology. It is explicitly shown that all quantum behaviors including Green's functions and the scattering matrix of translation-invariant non-commutative quantum field theories are thoroughly characterized by α∗-cohomology classes of the star products.
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. PMID:24849797
20 CFR 725.521 - Commutation of payments; lump sum awards.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false Commutation of payments; lump sum awards. 725.521 Section 725.521 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, AS AMENDED CLAIMS FOR BENEFITS UNDER PART C OF TITLE IV OF THE FEDERAL MINE SAFETY AND HEALTH...
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…
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…
Physical activity as a mediator of the relationship between active commuting to school and adiposity
Technology Transfer Automated Retrieval System (TEKTRAN)
Active commuting to school (ACS) has been associated with more moderate-to vigorous physical activity (MVPA) and decreased adiposity among youth. However, no studies have examined if MVPA mediates the relationship between ACS and adiposity. We hypothesized that ACS would be inversely associated with...
Ji, Un Cig; Obata, Nobuaki
2010-12-15
The implementation problem for the canonical commutation relation is reduced to a system of differential equations for Fock space operators containing new type of derivatives. We solve these differential equations systematically by means of quantum white noise calculus, and obtain the solution to the implementation problem.
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…
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…
2012-01-01
Background Route environments may influence people's active commuting positively and thereby contribute to public health. Assessments of route environments are, however, needed in order to better understand the possible relationship between active commuting and the route environment. The aim of this study was, therefore, to assess the potential associations between perceptions of whether the route environment on the whole hinders or stimulates bicycle commuting and perceptions of environmental factors. Methods The Active Commuting Route Environment Scale (ACRES) was used for the assessment of bicycle commuters' perceptions of their route environments in the inner urban parts of Greater Stockholm, Sweden. Bicycle commuters (n = 827) were recruited by advertisements in newspapers. Simultaneous multiple regression analyses were used to assess the relation between predictor variables (such as levels of exhaust fumes, noise, traffic speed, traffic congestion and greenery) and the outcome variable (hindering - stimulating route environments). Two models were run, (Model 1) without and (Model 2) with the item traffic: unsafe or safe included as a predictor. Results Overall, about 40% of the variance of hindering - stimulating route environments was explained by the environmental predictors in our models (Model 1, R2 = 0.415, and Model 2, R 2= 0.435). The regression equation for Model 1 was: y = 8.53 + 0.33 ugly or beautiful + 0.14 greenery + (-0.14) course of the route + (-0.13) exhaust fumes + (-0.09) congestion: all types of vehicles (p ≤ 0.019). The regression equation for Model 2 was y = 6.55 + 0.31 ugly or beautiful + 0.16 traffic: unsafe or safe + (-0.13) exhaust fumes + 0.12 greenery + (-0.12) course of the route (p ≤ 0.001). Conclusions The main results indicate that beautiful, green and safe route environments seem to be, independently of each other, stimulating factors for bicycle commuting in inner urban areas. On the other hand, exhaust fumes, traffic
Commuter exposure to particulate matter in public transportation modes in Hong Kong
NASA Astrophysics Data System (ADS)
Chan, L. Y.; Lau, W. L.; Lee, S. C.; Chan, C. Y.
This study examined commuter's exposure to respirable suspended particulate matters while commuting in public transportation modes. The survey was conducted between October 1999 and January 2000 in Hong Kong. A total of eight public transportation modes, that are bus, tram, public light bus, taxi, ferry, Kowloon-Canton Railway, Mass Transit Railway and Light Rail Transit, were selected in the study. They were grouped into four categories: (T1) railway transport; (T2) non-air-conditioned roadway transport; (T3) air-conditioned roadway transport and (T4) marine transport. Both PM 10 and PM 2.5 levels were investigated. The results indicate that the particulate level is greatly affected by the mode of transport as well as the ventilation system of the transport. The overall average PM 10 concentration level in T2 (147 μg m -3) is the highest and is followed by T4 (81 μg m -3) and T3 (65 μg m -3). The PM 10 level in T1 (50 μg m -3) is the lowest. Notably, the commuter exposure in tram (175 μg m -3) is the highest among all the monitored commuting modes. Commuting modes such as railway and air-conditioned vehicle are recommended as a substitute for non-air-conditioned vehicle. The PM 2.5 to PM 10 ratio in transports ranged from 63% to 78%. Higher PM 2.5 to PM 10 ratio is found in vehicles with air-conditioning system. For the double deck vehicle, higher PM 10 level has resulted in the lower deck. The average upper-deck to lower-deck PM 10 ratio is 0.836, 0.751 and 0.738 in air-conditioned bus, non-air-conditioned bus and non-air-conditioned tram, respectively. Typical concentration profiles in different transports are also presented.
NYPA/TH!NK Clean Commute Program Report – Inception through February 2003
Don Karner; James Francfort
2003-07-01
The Clean Commute Program uses TH!NK city electric vehicles from Ford Motor Company’s electric vehicle group, TH!NK Mobility, to demonstrate the feasibility of using electric transportation in urban applications. The primary Program partners are the New York Power Authority (NYPA) and Ford. The other Program partners providing funding and other support include the Metropolitan Transportation Authority, Metro North Railroad, Long Island Railroad, New York State Energy Research and Development Authority, Long Island Power Authority, New York State Department of Transportation, New York City Department of Transportation, and the U.S. Department of Energy’s Advanced Vehicle Testing Activity (AVTA). The data in this report is being collected via an internet-based questionnaire system by the AVTA through its subcontractor Electric Transportation Applications. Suburban New York City railroad commuters use the TH!NK city vehicles to commute from their private residences to railroad stations where they catch commuter trains into New York City. Electric vehicle charging infrastructure for the TH!NK cities is located at the commuters’ private residences as well as seven train stations. Eighty-seven commuters are using the TH!NK city vehicles, with 80% actively providing data to the AVTA. The participants have driven the vehicles nearly 150,000 miles since Program inception, avoiding the use of almost 7,000 gallons of gasoline. The TH!NK city vehicles are driven an average of between 180 and 230 miles per month, and over 95% of all trips taken with the TH!NK city vehicles replace trips previously taken in gasoline vehicles. This report covers the period from Program inception through February 2003.
Good, Nicholas; Mölter, Anna; Ackerson, Charis; Bachand, Annette; Carpenter, Taylor; Clark, Maggie L; Fedak, Kristen M; Kayne, Ashleigh; Koehler, Kirsten; Moore, Brianna; L'Orange, Christian; Quinn, Casey; Ugave, Viney; Stuart, Amy L; Peel, Jennifer L; Volckens, John
2016-01-01
Traffic-related air pollution is associated with increased mortality and morbidity, yet few studies have examined strategies to reduce individual exposure while commuting. The present study aimed to quantify how choice of mode and route type affects personal exposure to air pollutants during commuting. We analyzed within-person difference in exposures to multiple air pollutants (black carbon (BC), carbon monoxide (CO), ultrafine particle number concentration (PNC), and fine particulate matter (PM2.5)) during commutes between the home and workplace for 45 participants. Participants completed 8 days of commuting by car and bicycle on direct and alternative (reduced traffic) routes. Mean within-person exposures to BC, PM2.5, and PNC were higher when commuting by cycling than when driving, but mean CO exposure was lower when cycling. Exposures to CO and BC were reduced when commuting along alternative routes. When cumulative exposure was considered, the benefits from cycling were attenuated, in the case of CO, or exacerbated, in the case of particulate exposures, owing to the increased duration of the commute. Although choice of route can reduce mean exposure, the effect of route length and duration often offsets these reductions when cumulative exposure is considered. Furthermore, increased ventilation rate when cycling may result in a more harmful dose than inhalation at a lower ventilation rate. PMID:26507004
Good, Nicholas; Mölter, Anna; Ackerson, Charis; Bachand, Annette; Carpenter, Taylor; Clark, Maggie L; Fedak, Kristen M; Kayne, Ashleigh; Koehler, Kirsten; Moore, Brianna; L'Orange, Christian; Quinn, Casey; Ugave, Viney; Stuart, Amy L; Peel, Jennifer L; Volckens, John
2016-06-01
Traffic-related air pollution is associated with increased mortality and morbidity, yet few studies have examined strategies to reduce individual exposure while commuting. The present study aimed to quantify how choice of mode and route type affects personal exposure to air pollutants during commuting. We analyzed within-person difference in exposures to multiple air pollutants (black carbon (BC), carbon monoxide (CO), ultrafine particle number concentration (PNC), and fine particulate matter (PM2.5)) during commutes between the home and workplace for 45 participants. Participants completed 8 days of commuting by car and bicycle on direct and alternative (reduced traffic) routes. Mean within-person exposures to BC, PM2.5, and PNC were higher when commuting by cycling than when driving, but mean CO exposure was lower when cycling. Exposures to CO and BC were reduced when commuting along alternative routes. When cumulative exposure was considered, the benefits from cycling were attenuated, in the case of CO, or exacerbated, in the case of particulate exposures, owing to the increased duration of the commute. Although choice of route can reduce mean exposure, the effect of route length and duration often offsets these reductions when cumulative exposure is considered. Furthermore, increased ventilation rate when cycling may result in a more harmful dose than inhalation at a lower ventilation rate. PMID:26507004
Hybrid high direct current circuit interrupter
Rockot, Joseph H.; Mikesell, Harvey E.; Jha, Kamal N.
1998-01-01
A device and a method for interrupting very high direct currents (greater than 100,000 amperes) and simultaneously blocking high voltages (greater than 600 volts). The device utilizes a mechanical switch to carry very high currents continuously with low loss and a silicon controlled rectifier (SCR) to bypass the current around the mechanical switch while its contacts are separating. A commutation circuit, connected in parallel with the SCR, turns off the SCR by utilizing a resonant circuit to divert the SCR current after the switch opens.
Hybrid high direct current circuit interrupter
Rockot, J.H.; Mikesell, H.E.; Jha, K.N.
1998-08-11
A device and a method are disclosed for interrupting very high direct currents (greater than 100,000 amperes) and simultaneously blocking high voltages (greater than 600 volts). The device utilizes a mechanical switch to carry very high currents continuously with low loss and a silicon controlled rectifier (SCR) to bypass the current around the mechanical switch while its contacts are separating. A commutation circuit, connected in parallel with the SCR, turns off the SCR by utilizing a resonant circuit to divert the SCR current after the switch opens. 7 figs.
Rasmussen, Martin G.; Grøntved, Anders; Blond, Kim; Overvad, Kim; Tjønneland, Anne; Jensen, Majken K.; Østergaard, Lars
2016-01-01
second examination, respectively. Lastly, in the analysis of commuter cycling, multivariable HRs (95% CI) were 1, 0.72 (0.60, 0.87), 0.83 (0.69, 1.00), and 0.70 (0.57, 0.85) (p for trend = <0.001) for cycling 0, 1–60, 61–150, and >150 min/wk to work, respectively. The main limitation of the current study is the use of self-reported physical activity. Conclusions Commuter and recreational cycling was consistently associated with lower risk of T2D in Danish adults. Our results also provide evidence that late-in-life initiation of or continued engagement in cycling lowers risk of T2D. PMID:27403867
Tang, L; Sun, Y; Buelow, D; Gu, Z; Caliendo, A M; Pounds, S; Hayden, R T
2016-06-01
Given recent advances in the development of quantitative standards, particularly WHO international standards, efforts to better understand the commutability of reference materials have been made. Existing approaches in evaluating commutability include prediction intervals and correspondence analysis; however, the results obtained from existing approaches may be ambiguous. We have developed a "deviation-from-ideal" (DFI) approach to evaluate commutability of standards and applied it to the assessment of Epstein-Bar virus (EBV) load testing in four quantitative PCR assays, treating digital PCR as a reference assay. We then discuss advantages and limitations of the DFI approach as well as experimental design to best evaluate the commutability of an assay in practice. PMID:27076654
Georgia Institute of Technology School of Civil and Environmental Engineering researchers analyzed the 2004 vehicle activity data obtained from vehicles in the Atlanta Commuter Choice Value Pricing Initiative. The onboard monitoring equipment installed in each participating vehi...
76 FR 16469 - Application of Air Charter, Inc. D/B/A Air Flamenco for Commuter Authority
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-23
... it should not issue an order finding Air Charter, Inc. d/b/a Air Flamenco fit, willing, and able, and awarding it Commuter Air Carrier Authorization. DATES: Persons wishing to file objections should do so...
Quantum Fisher information and symmetric logarithmic derivative via anti-commutators
NASA Astrophysics Data System (ADS)
Liu, Jing; Chen, Jie; Jing, Xiao-Xing; Wang, Xiaoguang
2016-07-01
The symmetric logarithmic derivative (SLD) is a key quantity to obtain quantum Fisher information (QFI) and to construct the corresponding optimal measurements. Here we develop a method to calculate the SLD and QFI via anti-commutators. This method has originated from the Lyapunov representation and would be very useful for cases where the anti-commutators among the state and its partial derivative exhibit periodic properties. As an application, we discuss a class of states whose squares linearly depend on the states themselves, and give the corresponding analytical expressions of SLD and QFI. A noisy scenario of this class of states is also considered and discussed. Finally, we readily apply the method to the block-diagonal states and the multi-parameter estimation scenarios.
Panter, Jenna; Jones, Andrew; Van Sluijs, Esther; Griffin, Simon
2011-02-01
The purpose of this cross-sectional study was to examine the associations between active commuting behavior, levels of physical activity and distance to school in 9-10 year old children. Participants were children (n = 1824) who took part in the SPEEDY study (Sport, Physical activity and Eating behavior: Environmental Determinants in Young people). For both boys and girls, significant positive associations were observed between walking to school and physical activity and moderate-to-vigorous physical activity during weekday journey times (8-9 am and 3-4 pm), and the size of association also became stronger with increasing distance from school. Promotion of active commuting to school might be an important way to increase levels of physical activity in school children. PMID:21467592
Sims, T.R.; Jones, R.A. . Research and Development Dept.); Imece, A.F. )
1990-09-01
Islanding is one of the major concerns that electric power utilities have about the impact of distributed photovoltaic (PV) generation. Islanding is the isolated operation of PV systems after the interruption of utility power. This paper reports the results of a research project on the possible islanding operation of a section of a distribution feeder containing line-commutated static power converters. The approach of the project was to develop a computer model of the SPC to predict islanding operation and verify the model with laboratory and field tests. The computer model accurately predicted the operation of the SPC during islanding. Furthermore, the effect of general system parameters on the islanding performance of the Gemini line-commutated SPC are presented.
An ecological analysis of environmental correlates of active commuting in urban U.S.
Fan, Jessie X; Wen, Ming; Kowaleski-Jones, Lori
2014-11-01
We conduct a cross-sectional ecological analysis to examine environmental correlates of active commuting in 39,660 urban tracts using data from the 2010 Census, 2007-2011 American Community Survey, and other sources. The five-year average (2007-2011) prevalence is 3.05% for walking, 0.63% for biking, and 7.28% for public transportation to work, with higher prevalence for all modes in lower-income tracts. Environmental factors account for more variances in public transportation to work but economic and demographic factors account for more variances in walking and biking to work. Population density, median housing age, street connectivity, tree canopy, distance to parks, air quality, and county sprawl index are associated with active commuting, but the association can vary in size and direction for different transportation mode and for higher-income and lower-income tracts. PMID:25460907
Bevan, M.A.J.; Proctor, C.J.; Baker-Rogers, J.; Warren, N.D. )
1991-04-01
A portable air sampling system has been used to assess exposures to various substances while commuting by bicycle in an urban area. The major source of pollutants in this situation is motor vehicle exhaust emissions. Carbon monoxide, measured by electrochemical detection, was found at peak concentrations in excess of 62 ppm, with mean values over 16 individual 35-mm journeys being 10.5 ppm. Respirable suspended particulates, averaged over each journey period, were found at higher concentrations (mean 130 {mu}g m{sup {minus}3}) than would be expected in indoor situations. Mean exposure to benzene (at 56 {mu}g m{sup {minus}3}) and other aromatic volatile organic compounds was also relatively high. The influence of wind conditions on exposure was found to be significant. Commuting exposures to carbon monoxide, respirable suspended particulates, and aromatic VOCs were found to be higher than exposures in a busy high street and on common parkland.
Hermitization and the Poisson bracket-commutator correspondence as a consequence of averaging
NASA Astrophysics Data System (ADS)
Pesci, Adriana I.; Goldstein, Raymond E.; Uys, Hermann
2006-01-01
Here we present a study of the solutions and mathematical structure of the momentum-averaged Liouville (or Collisionless Boltzmann) equation in Fourier space. We show that the averaging procedure leads to a formalism identical to that of the density matrix of quantum mechanics. This mathematical mapping leaves the averages of all quantities unaltered and provides a unique way to construct the Hermitian version of a given operator. This seems to be the only method that resolves the ambiguity of Hermitization of operators that contain products of non-commuting variables. We also present a systematic perturbation scheme to evaluate correctly the classical solutions from the quantum ones and a formal proof of the approximate correspondence between the Poisson brackets and commutators.
An approach for modeling self-commutated static power converters for photovoltaic islanding studies
Imece, A.F. . Systems Development and Engineering Dept.); Jones, R.A.; Sims, T.R. ); Gross, C.A. . Dept. of Electrical Engineering)
1989-09-01
The safety of line crew personnel and others is a major concern of electric power utilities regarding the widespread use of grid-connected photo-volataic (PV) power sources. PV sources feed power back to a utility grid through Static Power Converters (SPC's), which are designed to shut down when disconnected from the grid. SPC's have been shown to continue to operate or run-on under certain conditions. A model for a commercially available self-commutated SPC is developed to investigate the conditions under which isolated operation (islanding) occurs. The approach used in modeling the SPC is unique in islanding studies. It is based on solving complex-ac system equations and Phase-Locked Loop differential equations simultaneously to determine the SPC response. The model accurately and optimistically predicts the islanding performance of the self-commutated SPC, as verified in laboratory experiments and detailed computer simulations.
Invariants of Lie algebras representable as semidirect sums with a commutative ideal
Vorontsov, Alexander S
2009-08-31
Explicit formulae for invariants of the coadjoint representation are presented for Lie algebras that are semidirect sums of a classical semisimple Lie algebra with a commutative ideal with respect to a representation of minimal dimension or to a kth tensor power of such a representation. These formulae enable one to apply some known constructions of complete commutative families and to compare integrable systems obtained in this way. A completeness criterion for a family constructed by the method of subalgebra chains is suggested and a conjecture is formulated concerning the equivalence of the general Sadetov method and a modification of the method of shifting the argument, which was suggested earlier by Brailov. Bibliography: 12 titles.
An Ecological Analysis of Environmental Correlates of Active Commuting in Urban U.S.
Fan, Jessie X.; Wen, Ming; Kowaleski-Jones, Lori
2014-01-01
We conduct a cross-sectional ecological analysis to examine environmental correlates of active commuting in 39,660 urban tracts using data from the 2010 Census, 2007-2011 American Community Survey, and other sources. The five-year average (2007-2011) prevalence is 3.05% for walking, 0.63% for biking, and 7.28% for public transportation to work, with higher prevalence for all modes in lower-income tracts. Environmental factors account for more variances in public transportation to work but economic and demographic factors account for more variances in walking and biking to work. Population density, median housing age, street connectivity, tree canopy, distance to parks, air quality, and county sprawl index are associated with active commuting, but the association can vary in size and direction for different transportation mode and for higher-income and lower-income tracts. PMID:25460907
McMinn, David; Oreskovic, Nicolas M; Aitkenhead, Matt J; Johnston, Derek W; Murtagh, Shemane; Rowe, David A
2014-05-01
Active school travel is in decline. An understanding of the potential determinants of health-enhancing physical activity during the school commute may help to inform interventions aimed at reversing these trends. The purpose of this study was to identify the physical environmental factors associated with health-enhancing physical activity during the school commute. Data were collected in 2009 on 166 children commuting home from school in Scotland. Data on location and physical activity were measured using global positioning systems (GPS) and accelerometers, and mapped using geographical information systems (GIS). Multi-level logistic regression models accounting for repeated observations within participants were used to test for associations between each land-use category (road/track/path, other man-made, greenspace, other natural) and moderate-to-vigorous physical activity (MVPA). Thirty-nine children provided 2,782 matched data points. Over one third (37.1%) of children's school commute time was spent in MVPA. Children commuted approximately equal amounts of time via natural and man-made land-uses (50.2% and 49.8% respectively). Commuting via road/track/path was associated with increased likelihood of MVPA (Exp(B)=1.23, P <0.05), but this association was not seen for commuting via other manmade land-uses. No association was noted between greenspace use and MVPA, but travelling via other natural land-uses was associated with lower odds of MVPA (Exp(B)=0.32, P <0.05). Children spend equal amounts of time commuting to school via man-made and natural land-uses, yet man-made transportation route infrastructure appears to provide greater opportunities for achieving health-enhancing physical activity levels. PMID:24893034
Passenger demographics and subjective response to commuter aircraft in the northeast
NASA Technical Reports Server (NTRS)
Noskowitz, D.; Jacobson, I. D.
1974-01-01
Results are compared for comfort and environmental studies taken in conjunction with a STOL program. Data were taken on flights of four different airlines, each flying different aircraft. Two of the lines are classified as commuter airlines flying between relatively close destinations. The aircraft involved are: the De Havilland Twin Otter, a Canadian aircraft; the French Nord 262; the Beechcraft 99 Airliner and the Sikorsky S-61 helicopter, both American.
NASA Astrophysics Data System (ADS)
Pogrebkov, A. K.
2016-06-01
We show that the non-Abelian Hirota difference equation is directly related to a commutator identity on an associative algebra. Evolutions generated by similarity transformations of elements of this algebra lead to a linear difference equation. We develop a special dressing procedure that results in an integrable non-Abelian Hirota difference equation and propose two regular reduction procedures that lead to a set of known equations, Abelian or non-Abelian, and also to some new integrable equations.
Caballar, Roland Cristopher F.; Ocampo, Leonard R.; Galapon, Eric A.
2010-06-15
Internal symmetries can be used to classify multiple solutions to the time-energy canonical commutation relation (TE-CCR). The dynamical behavior of solutions to the TE-CCR possessing particular internal symmetries involving time reversal differ significantly from solutions to the TE-CCR without those particular symmetries, implying a connection between the internal symmetries of a quantum system, its internal unitary dynamics, and the TE-CCR.
Sleepiness, Long Distance Commuting and Night Work as Predictors of Driving Performance
Di Milia, Lee; Rogers, Naomi L.; Åkerstedt, Torbjörn
2012-01-01
Few studies have examined the effect of working night shift and long distance commuting. We examined the association between several sleep related and demographic variables, commuting distance, night work and use of mobile phones on driving performance. We used a prospective design to recruit participants and conducted a telephone survey (n = 649). The survey collected demographic and journey details, work and sleep history and driving performance concerning the day the participant was recruited. Participants also completed the Karolinska Sleepiness Scale and the Epworth Sleepiness Scale. Night workers reported significantly more sleepiness, shorter sleep duration and commuting longer distances. Seven variables were significant predictors of lane crossing. The strongest predictor was acute sleepiness (OR = 5.25, CI, 1.42–19.49, p<0.01) followed by driving ≥150 kms (OR = 3.61, CI, 1.66–7.81, p<0.001), obtaining less than 10 hours sleep in the previous 48 hours (OR = 2.58, CI, 1.03–6.46, p<0.05), driving after night shift (OR = 2.19, CI, 1.24–3.88, p<0.001), being <43 years old (OR = 1.95, CI, 1.11–3.41, p<0.05) and using mobile phones during the journey (OR = 1.90, CI, 1.10–3.27, p<0.05). Sleep related variables, long-distance commuting and night work have a major impact on lane crossing. Several interventions should be considered to reduce the level of sleepiness in night workers. PMID:23029278
NASA Astrophysics Data System (ADS)
Ragettli, Martina S.; Corradi, Elisabetta; Braun-Fahrländer, Charlotte; Schindler, Christian; de Nazelle, Audrey; Jerrett, Michael; Ducret-Stich, Regina E.; Künzli, Nino; Phuleria, Harish C.
2013-10-01
A better understanding of ultrafine particle (UFP) exposure in different urban transport microenvironments is important for epidemiological exposure assessments and for policy making. Three sub-studies were performed to characterize personal exposure to UFP concentration and average particle size distribution diameters in frequently traveled commuter microenvironments in the city of Basel, Switzerland. First, the spatial variation of sidewalk UFP exposures within urban areas and transport-specific microenvironments was explored. Second, exposure to UFP concentration and average particle size were quantified for five modes of transportation (walking, bicycle, bus, tram, car) during different times of the day and week, along the same route. Finally, the contribution of bicycle commuting along two different routes (along main roads, away from main roads) to total daily exposures was assessed by 24-h personal measurements. In general, smaller average particle sizes and higher UFP levels were measured at places and for travel modes in close proximity to traffic. Average trip UFP concentrations were higher in car (31,784 particles cm-³) and on bicycle (22,660 particles cm-³) compared to walking (19,481 particles cm-³) and public transportation (14,055-18,818 particles cm-³). Concentrations were highest for all travel modes during weekday morning rush hours, compared to other time periods. UFP concentration was lowest in bus, regardless of time period. Bicycle travel along main streets between home and work place (24 min on average) contributed 21% and 5% to total daily UFP exposure in winter and summer, respectively. Contribution of bicycle commutes to total daily UFP exposure could be reduced by half if main roads are avoided. Our results show the importance of considering commuter behavior and route choice in exposure assessment studies.
Are GIS-modelled routes a useful proxy for the actual routes followed by commuters?
Dalton, Alice M; Jones, Andrew P; Panter, Jenna; Ogilvie, David
2015-01-01
Active commuting offers the potential to increase physical activity among adults by being built into daily routines. Characteristics of the route to work may influence propensity to walk or cycle. Geographic information system (GIS) software is often used to explore this by modelling routes between home and work. However, if the validity of modelled routes depends on the mode of travel used, studies of environmental determinants of travel may be biased. We aimed to understand how well modelled routes reflect those actually taken, and what characteristics explain these differences. We compared modelled GIS shortest path routes with actual routes measured using QStarz BT-Q1000X Global Positioning System (GPS) devices in a free-living sample of adults working in Cambridge and using varying travel modes. Predictors of differences, according to length and percentage overlap, between the two route sets were assessed using multilevel regression models and concordance coefficients. The 276 trips, made by 51 participants, were on average 27% further than modelled routes, with an average geographical overlap of 39%. However, predictability of the route depended on travel mode. For route length, there was moderate-to-substantial agreement for journeys made on foot and by bicycle. Route overlap was lowest for trips made by car plus walk (22%). The magnitude of difference depended on other journey characteristics, including travelling via intermediate destinations, distance, and use of busy roads. In conclusion, GIS routes may be acceptable for distance estimation and to explore potential routes, particularly active commuting. However, GPS should be used to obtain accurate estimates of environmental contexts in which commuting behaviour actually occurs. Public health researchers should bear these considerations in mind when studying the geographical determinants and health implications of commuting behaviour, and when recommending policy changes to encourage active travel. PMID
A vector supersymmetry killing IR divergences in non-commutative gauge theories
NASA Astrophysics Data System (ADS)
Blaschke, D. N.
2008-02-01
This is a report on the joint work with François Gieres, Stefan Hohenegger, Olivier Piguet and Manfred Schweda. We consider a non-commutative U(1) gauge theory with an extension which was originally proposed by A. A. Slavnov [3, 4] in order to get rid of UV/IR mixing problems. Here we show, that the improved IR behaviour of this model is mainly due to the appearence of a linear vector supersymmetry.
A travel mode comparison of commuters' exposures to air pollutants in Barcelona
NASA Astrophysics Data System (ADS)
de Nazelle, Audrey; Fruin, Scott; Westerdahl, Dane; Martinez, David; Ripoll, Anna; Kubesch, Nadine; Nieuwenhuijsen, Mark
2012-11-01
Daily commutes may contribute disproportionately to overall daily inhalations of urban air contaminants. Understanding factors that explain variability of exposures during travel, and especially differences across transportation modes, is essential to accurately assess health impacts of traffic emissions and to develop effective mitigating measures. We evaluated exposures and inhaled doses of air pollution and assessed factors that contributed to their variability in different travel modes in Barcelona. Black carbon (BC), ultrafine particles (UFP), carbon monoxide (CO), fine particle mass (PM2.5) and carbon dioxide (CO2) were measured and compared across walk, bike, bus, and car modes for a total of 172 trips made on two different round trip routes. On average, the car mode experienced highest concentrations for all contaminants. In pairwise t-tests between concurrent mode runs, statistically significant differences were found for cars compared to walking and biking. Car-to-walk or car-to-bike concentration ratios ranged from 1.3 for CO2 to 25 for CO and were 2-3 for PM2.5, BC, and UFP. In multivariate analyses, travel mode explained the greatest variability in travel exposures, from 8% for PM2.5 to 70% for CO. Different modal patterns emerged when estimating daily inhaled dose, with active commuters' two to three times greater total inhalation volume during travel producing about equal UFP and BC daily inhaled doses to car commuters and 33-50% higher UFP and BC doses compared to bus commuters. These findings, however, are specific to the bike and pedestrian lanes in this study being immediately adjacent to the roadways measured. Dedicated bike or pedestrian routes away from traffic would lead to lower active travel doses.
Karanasiou, Angeliki; Viana, Mar; Querol, Xavier; Moreno, Teresa; de Leeuw, Frank
2014-08-15
Commuting is considered as one of the high-exposure periods among various daily activities, especially in high vehicle-density metropolitan areas. There is a growing awareness of the need to change our transportation habits by reducing our use of cars and shifting instead to active transport, i.e. walking or cycling. A review was undertaken using the ISI web of knowledge database with the objective to better understand personal exposure during commuting by different modes of transport, and to suggest potential strategies to minimise exposure. The air pollutants studied include particulate matter, PM black carbon, BC and particle number concentration. We focused only in European studies in order to have comparable situation in terms of vehicle fleet and policy regulations applied. Studies on personal exposure to air pollutants during car commuting are more numerous than those dealing with other types of transport, and typically conclude by emphasising that travelling by car involves exposure to relatively high particulate matter, PM exposure concentrations. Thus, compared to other transport methods, travelling by car has been shown to involve exposure both to higher PM and BC as compared with cycling. Widespread dependence on private car transport has produced a significant daily health threat to the urban commuter. However, a forward-looking, integrated transport policy, involving the phased renovation of existing public vehicles and the withdrawal of the more polluting private vehicles, combined with incentives to use public transport and the encouragement of commuter physical exercise, would reduce commuters' exposure. PMID:24907613
Chrest, David P.; Wheaton, William D.
2010-01-01
By understanding the movement patterns of people, mathematical modelers can develop models that can better analyze and predict the spread of infectious diseases. People can come into close contact in their workplaces. This report describes methods to develop georeferenced commuting patterns that can be used to characterize the work-related movement of US populations and help agent-based modelers predict workplace contacts that result in disease transmission. We used a census data product called “Census Spatial Tabulation: Census Track of Work by Census Tract of Residence (STP64)” as the data source to develop commuting pattern data for agent-based synthesized populations databases and to develop map products to visualize commuting patterns in the United States. The three primary maps we developed show inbound, outbound, and net change levels of inbound versus outbound commuters by census tract for the year 2000. Net change counts of commuters are visualized as elevations. The results can be used to quantify and assign commuting patterns of synthesized populations among different census tracts. PMID:20505785
DeWeese, Robin; Ohri-Vachaspati, Punam
2016-01-01
Background Active commuting to school (ACS) increases students' daily physical activity, but associations between student weight and ACS are inconsistent. Few studies examining ACS and weight account for distance commuted. This study examines the association between students' weight status and ACS, taking into account distance to school. Methods In 2009–10 a random digit-dial household survey conducted in low-income minority cities collected information about ACS for 1 randomly selected school-going student per household. Parents provided measured heights and weights. Distance commuted was obtained using geocoded home and school addresses. Multivariate regression analyses assessed associations of ACS and distance commuted with weight status. Results 36.6% of students were overweight/obese; 47.2% engaged in ACS. Distance walked/biked to school was associated with 7% lower odds of overweight/obesity (OR = 0.93, 95% CI: 0.88–0.99). Without distance commuted in the model, ACS was not associated with students' weight status. Compared with no ACS, ACS greater than a half-mile was associated with 65% lower odds of a student being overweight/obese (OR = 0.35, 95% CI: 0.16–0.78); ACS less than a half-mile was not. Conclusions ACS is significantly inversely associated with overweight/obesity among students who commute beyond a one-half mile threshold. PMID:25473961
Features of a Health-Oriented Education Program during Daily Commutes: A Qualitative Study
Ramezankhani, Ali; Heydarabadi, Akbar Babaei; Ghaffari, Mohtasham; Mehrabi, Yadollah; Kazemi, Sadegh
2016-01-01
Introduction Today, despite scientific advances, many people spend more time and distance between home and their workplaces because of various economic and population reasons. The aim of this study was to identify features of an appropriate health education program during commutes for factory staff at Ardakan county (Yazd province, Iran). Methods This qualitative study was conducted via the phenomenological method in 2014. The population of this study was members of the staff of Ardakan Steel Company. Nineteen specialists and 11 members of the factory’s staff were invited to participate in the study, and data were collected using semi-structured interviews. The interviews took 20 to 40 minutes, and their content was analyzed using content analysis. Results Extraction of codes and themes and their placement in this study showed that an educational program during commutes should have nine features to have the desired effectiveness, i.e., the program must be audience-oriented, repeatable, participatory, technology-based, combinational, supportive, and motivational and interesting. Also, the program should have environmental and organizational support, and it must be evaluated for its effectiveness. Conclusion Considering appropriate features of a health education program in educational situations, especially interventions related to daily commutes, is very important because the effectiveness of such health-oriented educational programs must be ensured. PMID:27504166
Boundedness of certain commutators over non-homogeneous metric measure spaces
NASA Astrophysics Data System (ADS)
Lin, Haibo; Wu, Suqing; Yang, Dachun
2016-06-01
Let ({X},d,μ ) be a metric measure space satisfying the so-called upper doubling condition and the geometrically doubling condition. Let T be a Calderón-Zygmund operator with kernel satisfying only the size condition and some Hörmander-type condition, and bin widetilde{RBMO}(μ ) (the regularized BMO space with the discrete coefficient). In this paper, the authors establish the boundedness of the commutator T_b:=bT-Tb generated by T and b from the atomic Hardy space widetilde{H}^1(μ ) with the discrete coefficient into the weak Lebesgue space L^{1, ∞}(μ ) . From this and an interpolation theorem for sublinear operators which is also proved in this paper, the authors further show that the commutator T_b is bounded on L^p(μ ) for all pin (1,∞) . Moreover, the boundedness of the commutator generated by the generalized fractional integral T_α (α in (0,1)) and the widetilde{RBMO}(μ ) function from widetilde{H}^1(μ ) into L^{1/{(1-α )}, ∞}(μ ) is also presented.
NASA Astrophysics Data System (ADS)
Albano, James A.; Messinger, David W.; Rotman, Stanley R.
2012-07-01
Spectral image analysis problems often begin by applying a transformation that generates an alternative representation of the spectral data with the intention of exposing hidden features not discernable in the original space. We introduce and demonstrate a transformation based on a Markov-chain model of a random walk on a graph via application to spectral image clustering. The random walk is quantified by a measure known as the average commute time distance (CTD), which is the average length that a random walker takes, when starting at one node, to transition to another and return to the starting node. This distance metric has the important characteristic of increasing when the number of paths between two nodes decreases and/or the lengths of those paths increase. Once a similarity graph is built on the spectral data, a transformation based on an eigendecomposition of the graph Laplacian matrix is applied that embeds the nodes of the graph into a Euclidean space with the separation between nodes equal to the square-root of the average commute time distance. This is referred to as the Commute Time Distance transformation. As an example of the utility of this data transformation, results are shown for standard clustering algorithms applied to hyperspectral data sets.
The FM-007: An advanced jet commuter for HUB to spoke transportation
NASA Technical Reports Server (NTRS)
Blouke, Peter Scott; Engel, George Bryan; Fordham, Kari Suzanne; Layne, Steven James; Moore, Joel David; Shaver, Frederick Martin; Thornton, Douglas Hershal, Jr.
1991-01-01
Due to the increasing need for new commuter aircraft, the FM-007 is proposed, a technologically advanced jet propelled short takeoff and landing (STOL) airplane. The proposed commuter is designed for hub to spoke air travel. In order to reduce drag, natural laminar flow technology is integrated into the design using the natural laminar flow airfoil section for the wing. A three lifting surface configuration provides for more efficient cruise flight. This unique design includes a small forward wing (canard), a rear mounted high aspect ratio main wing, and a small horizontal stabilizer high atop the vertical tail. These three surfaces act together to reduce drag by minimizing the downward force the horizontal stabilizer has to account for due to the nose down pitching moment. Commuter aircraft must also incorporate passenger comfort. This is achieved by providing a spacious pressurized cabin with a large galley and reduced cabin noise due to incorporation of noise reduction gear. A basic oval design is adopted, as opposed to a circular design in order to allow for the seating of five passengers abreast. To get STOL capability, an over the wing blown flap is used using a Rolls Royce Tay series engine.
Commuting symmetry operators of the Dirac equation, Killing-Yano and Schouten-Nijenhuis brackets
NASA Astrophysics Data System (ADS)
Cariglia, Marco; Krtouš, Pavel; Kubizňák, David
2011-07-01
In this paper we derive the most general first-order symmetry operator commuting with the Dirac operator in all dimensions and signatures. Such an operator splits into Clifford even and Clifford odd parts which are given in terms of odd Killing-Yano and even closed conformal Killing-Yano inhomogeneous forms, respectively. We study commutators of these symmetry operators and give necessary and sufficient conditions under which they remain of the first-order. In this specific setting we can introduce a Killing-Yano bracket, a bilinear operation acting on odd Killing-Yano and even closed conformal Killing-Yano forms, and demonstrate that it is closely related to the Schouten-Nijenhuis bracket. An important nontrivial example of vanishing Killing-Yano brackets is given by Dirac symmetry operators generated from the principal conformal Killing-Yano tensor [hep-th/0612029]. We show that among these operators one can find a complete subset of mutually commuting operators. These operators underlie separability of the Dirac equation in Kerr-NUT-(A)dS spacetimes in all dimensions [arXiv:0711.0078].
Simultaneous measurement of non-commuting observables in circuit QED: Experiment
NASA Astrophysics Data System (ADS)
Hacohen-Gourgy, Shay; Martin, Leigh; Flurin, Emmanuel; Whaley, Brigitta; Siddiqi, Irfan
The existence of incompatible measurements lies at the heart of numerous fundamental concepts in quantum mechanics, such as entanglement, contextuality and measurement-disturbance tradeoffs. We implement a novel technique for simultaneously and continuously measuring a pair of non-commuting observables in a circuit-QED architecture, which features a transmon qubit coupled to two modes of an electromagnetic cavity. By driving the transmon on resonance, we form an effective, low-frequency two-level system on which we perform the non-commuting measurements. To this end, we use microwave tones near the cavity's resonances to implement cooling and backaction-evading measurements familiar from optomechanics. Control of the relative amplitude and phase of these sideband tones enables qubit state measurement along an arbitrary axis of the Bloch sphere. We apply this technique to both modes of the cavity simultaneously, with distinct axes chosen for each mode. This realizes a continuous and simultaneous measurement of two non-commuting observables. We use high quantum-efficiency parametric amplifiers to track the resulting quantum trajectories of the qubit, enabling a measurement of the mutual disturbance of the two observables. This research is supported by the ARO.
NASA Astrophysics Data System (ADS)
Matone, Marco
2015-11-01
We show that there are {\\it 13 types} of commutator algebras leading to the new closed forms of the Baker-Campbell-Hausdorff (BCH) formula $$\\exp(X)\\exp(Y)\\exp(Z)=\\exp({AX+BZ+CY+DI}) \\ , $$ derived in arXiv:1502.06589, JHEP {\\bf 1505} (2015) 113. This includes, as a particular case, $\\exp(X) \\exp(Z)$, with $[X,Z]$ containing other elements in addition to $X$ and $Z$. The algorithm exploits the associativity of the BCH formula and is based on the decomposition $\\exp(X)\\exp(Y)\\exp(Z)=\\exp(X)\\exp({\\alpha Y}) \\exp({(1-\\alpha) Y}) \\exp(Z)$, with $\\alpha$ fixed in such a way that it reduces to $\\exp({\\tilde X})\\exp({\\tilde Y})$, with $\\tilde X$ and $\\tilde Y$ satisfying the Van-Brunt and Visser condition $[\\tilde X,\\tilde Y]=\\tilde u\\tilde X+\\tilde v\\tilde Y+\\tilde cI$. It turns out that $e^\\alpha$ satisfies, in the generic case, an algebraic equation whose exponents depend on the parameters defining the commutator algebra. In nine {\\it types} of commutator algebras, such an equation leads to rational solutions for $\\alpha$. We find all the equations that characterize the solution of the above decomposition problem by combining it with the Jacobi identity.
Xia, ChangYu; Liu, Ou; Wang, LanZhen
2012-01-01
Background Commutable reference materials (RMs) are suitable for end-users for evaluating the metrological traceability of values obtained using routine measurement systems. We assessed the performance of 6 routine measurement systems with validated secondary RMs. Methods We tested the homogeneity, stability, and commutability of 5 minimally processed human serum pools according to the standard guidelines. The serum pools were assigned values as per the reference procedure of the United States Centers for Disease Control and were used to evaluate the trueness of results from 6 commercial measurement systems based on enzymatic methods: 3 glucose oxidase (GOD) and 3 hexokinase (HK) methods. Results The prepared RMs were validated to be sufficiently homogenous, stable, and commutable with the patient samples. Method bias varied for different systems: GOD01, -0.17 to 2.88%; GOD02, 1.66 to 4.58%; GOD03, -0.17 to 3.14%; HK01, -3.48 to -0.85%; HK02, -3.83 to -0.11%, and HK03, -1.82 to -0.27%. Conclusions We observed that the prepared serum glucose RMs were qualified for trueness assessment. Most of the measurement systems met the minimal quality specifications. PMID:22779064
Elimination of current spikes in buck power converters
NASA Technical Reports Server (NTRS)
Mclyman, W. T. (Inventor)
1981-01-01
Current spikes in a buck power converter due to commutating diode turn-off time are eliminated by using a tapped inductor in the converter with the tap connected to the switching transistor. The commutating diode is not in the usual place, but is instead connected to conduct current from one end of the tapped inductor remote from the load during the interval in which the transistor is not conducting. In the case of a converter having a center-tapped (primary and secondary) transformer between two switching power transistors operated in a push-pull mode and two rectifying diodes in the secondary circuit, current spikes due to transformer saturation are also eliminated by using a tapped inductor in the converter with the tap connected to the rectifying diodes and a diode connected to conduct current from one end of the tapped inductor remote from the load during the interval in which the transistors are not conducting.
Jiménez-López, J; Llorent-Martínez, E J; Ortega-Barrales, P; Ruiz-Medina, A
2014-01-01
Citrinin is a toxic secondary metabolite first isolated from Penicillium citrinum, although is also produced by other species of Penicillium and Aspergillus. It has highly toxic, mutagenic, teratogenic and carcinogenic properties and is often found in crops, vegetables and fruit. To our knowledge there is no specific legislation on maximum levels permitted for citrinin, so no official analytical method is currently available for its determination. Our laboratory developed a fluorometric flow-through optosensor using Sephadex SPC-25 as solid support. Multi-commutated flow injection analysis was used for the construction of the manifold and for handling solutions. In this way, we minimised waste generation and human intervention, which are critical aspects when dealing with highly toxic compounds such as citrinin. The optimum excitation/emission wavelengths were set at 330/494 nm; the calibration curve was linear in the concentration range 35-900 ng ml⁻¹. A detection limit of 10.5 ng ml⁻¹ and relative standard deviations (RSDs) lower than 3% were obtained. The developed optosensor was applied to the determination of citrinin in rice and dietary supplements containing red yeast rice. PMID:25203115
Aging commuter aeroplanes: Fatigue evaluation and control methods
NASA Technical Reports Server (NTRS)
Emmerson, A. J.
1992-01-01
The loss of reliability in aircraft is caused by two broad classes of problems. There are those problems which are self evident and hazardous rather than catastrophic. These are the problem areas where characteristically there have been multiple overhauls, repairs, and replacements, and where aging really means the results of repair ineffectiveness that accumulates. The other class of the problem is the insidious and potentially catastrophic class. It includes the progressive deterioration of items that are not maintained, and often cannot be maintained because the deterioration cannot be seen. It includes the loss of physical properties in adhesives and other organic compounds, corrosion, and the response of repeated loads. Dealt with here is a currently unnecessarily troublesome aspect of that response. Although we must remain concerned about those types of aircraft which have been certified under a design standard or operational rule which embodies the elementary fail-safe concept and which have not been subjected to a subsequent structural audit, the focus here is on types of aircraft for which fatigue and damage tolerance evaluation was not required as a condition of certification.
NASA Astrophysics Data System (ADS)
Hagiwara, Makoto; Pham, Phuong Viet; Akagi, Hirofumi
This paper deals with a 50-MW self-commutated BTB (Back-To-Back) system intended for power-flow control between transmission networks. It focuses on the dynamic behavior of the BTB system during single-line-to-ground (SLG) faults. During an SLG fault, a dc magnetic deviation appears in the converter-transformers used for the BTB system just after the occurrence and restoration of the fault. It is indispensable to understand an amount of deviation because it may bring magnetic saturation as well as a large amount of magnetizing current to the transformers. This paper derives theoretical equations related to the deviation during the SLG fault. The theoretical analysis developed in this paper would make significant contributions to designing the transformers.
Crash Rates of Scheduled Commuter and Air Carrier Flights Before and After a Regulatory Change
Baker, Susan P.; Groff, Loren; Haaland, Wren; Qiang, Yandong; Rebok, George W.; Li, Guohua
2010-01-01
Introduction In 1997, in an effort to reduce the crash rate of scheduled commuter flights, the FAA required aircraft with 10–30 passenger seats to operate under stricter rules. Training and other requirements of 14 CFR Part 121 rules were applied to these midsize commuters, which previously had operated under the less strict Part 135 rules. Published crash rates obscured changes related to aircraft size. This research was undertaken to determine whether the rule change affected crash rates of aircraft with 10–30 passenger seats. Method We determined the number of passenger seats on each Part 135 or Part 121 aircraft that crashed between 1983 and 2007. For aircraft with < 10, 10–30, and > 30 seats, we estimated the numbers of departures and crash rates, adjusting for changes in total departures and numbers of in-service aircraft. Results The Part 135 crash rate tripled in 1997 when commuters with 10–30 seats were excluded, reflecting the administrative change. However, the crash rate of aircraft with 10–30 passenger seats began to decline 4 yr before the rule change; thereafter, their rate was lower than for larger aircraft. The fleet size of aircraft with 10–30 passenger seats increased from 1983 to 1997, then declined as they were replaced with larger aircraft in response to the rule change. Discussion No effect of the rule change on crash rates of 10–30-seat aircraft was apparent. The decline in their crash rates began before the rule change and may have been related to the 1992 requirement for ground proximity warning devices. PMID:19378909
Neighborhood Perceptions and Active School Commuting in Low-Income Cities
DeWeese, Robin S.; Yedidia, Michael J.; Tulloch, David L.; Ohri-Vachaspati, Punam
2016-01-01
Background Few children accumulate the recommended ≥60 minutes of physical activity each day. Active travel to and from school (ATS) is a potential source of increased activity for children, accounting for 22% of total trips and time spent traveling by school-aged children. Purpose This study identifies the association of parents’ perceptions of the neighborhood, geospatial variables, and demographic characteristics with ATS among students in four low-income, densely populated urban communities with predominantly minority populations. Methods Data were collected in 2009–2010 from households with school-attending children in four low-income New Jersey cities. Multivariate logistic regression analyses (n=765) identified predictors of ATS. Analyses were conducted in 2012. Results In all, 54% of students actively commuted to school. Students whose parents perceived the neighborhood as very unpleasant for activity were less likely (OR=0.39) to actively commute, as were students living farther from school, with a 6% reduction in ATS for every 0.10 mile increase in distance to school. Perceptions of crime, traffic, and sidewalk conditions were not predictors of ATS. Conclusions Parents’ perceptions of the pleasantness of the neighborhood, independent of the effects of distance from school, may outweigh concerns about crime, traffic, or conditions of sidewalks in predicting active commuting to school in the low-income urban communities studied. Efforts such as cleaning up graffiti, taking care of abandoned buildings, and providing shade trees to improve neighborhood environments are likely to increase ATS, as are efforts that encourage locating schools closer to the populations they serve. PMID:24050414
Commuters' exposure to PM1 by common travel modes in Shanghai
NASA Astrophysics Data System (ADS)
Yu, Qi; Lu, Yi; Xiao, Shan; Shen, Junxiu; Li, Xun; Ma, Weichun; Chen, Limin
2012-11-01
A study on commuter's exposure to PM1 in Shanghai was presented. Commuters' real-time exposure concentrations by the common travel modes (bus, walking, cycling, taxi and subway) were measured by DustTrak™ dust monitors, and the average exposure concentrations and inhalation doses were analyzed. The lengths of the routes were designed to be within 30-min walking distance. The average PM1 exposure concentrations during commuting were 0.147 ± 0.092 mg m-3, 0.145 ± 0.088 mg m-3, 0.140 ± 0.086 mg m-3, 0.139 ± 0.086 mg m-3 and 0.122 ± 0.077 mg m-3 for the bus, walking, cycling, taxi and subway trips respectively. The concentrations in the microenvironments were 0.147 ± 0.096 mg m-3, 0.155 ± 0.098 mg m-3, 0.142 ± 0.092 mg m-3 and 0.079 ± 0.051 mg m-3 for the bus station, bus, taxi and train respectively. The concentrations in the microenvironments were close to those in Guangzhou and higher compared to the results in London, Sydney, Florence, etc. The combined effect of exposure concentration, travel time and inhalation rate led to different inter-mode relationship of inhalation doses compared to that of exposure concentrations. The inhalation doses were 54.5 ± 38.9 μg, 45.2 ± 30.1 μg, 29.2 ± 25.4 μg, 28.6 ± 25.9 μg and 12.8 ± 13.4 μg for the cycling, walking, bus, subway and taxi trips respectively. The outdoor fractions of the inhalation doses by bus, taxi and subway were much higher than the indoor fractions.
Unified commutation-pruning technique for efficient computation of composite DFTs
NASA Astrophysics Data System (ADS)
Castro-Palazuelos, David E.; Medina-Melendrez, Modesto Gpe.; Torres-Roman, Deni L.; Shkvarko, Yuriy V.
2015-12-01
An efficient computation of a composite length discrete Fourier transform (DFT), as well as a fast Fourier transform (FFT) of both time and space data sequences in uncertain (non-sparse or sparse) computational scenarios, requires specific processing algorithms. Traditional algorithms typically employ some pruning methods without any commutations, which prevents them from attaining the potential computational efficiency. In this paper, we propose an alternative unified approach with automatic commutations between three computational modalities aimed at efficient computations of the pruned DFTs adapted for variable composite lengths of the non-sparse input-output data. The first modality is an implementation of the direct computation of a composite length DFT, the second one employs the second-order recursive filtering method, and the third one performs the new pruned decomposed transform. The pruned decomposed transform algorithm performs the decimation in time or space (DIT) data acquisition domain and, then, decimation in frequency (DIF). The unified combination of these three algorithms is addressed as the DFTCOMM technique. Based on the treatment of the combinational-type hypotheses testing optimization problem of preferable allocations between all feasible commuting-pruning modalities, we have found the global optimal solution to the pruning problem that always requires a fewer or, at most, the same number of arithmetic operations than other feasible modalities. The DFTCOMM method outperforms the existing competing pruning techniques in the sense of attainable savings in the number of required arithmetic operations. It requires fewer or at most the same number of arithmetic operations for its execution than any other of the competing pruning methods reported in the literature. Finally, we provide the comparison of the DFTCOMM with the recently developed sparse fast Fourier transform (SFFT) algorithmic family. We feature that, in the sensing scenarios with
Influence of Sports, Physical Education, and Active Commuting to School on Adolescent Weight Status
Beach, Michael L.; Longacre, Meghan R.; MacKenzie, Todd; Titus, Linda J.; Rundle, Andrew G.; Dalton, Madeline A.
2012-01-01
OBJECTIVE: To compare the associations between weight status and different forms of physical activity among adolescents. METHODS: We conducted telephone surveys with 1718 New Hampshire and Vermont high school students and their parents as part of a longitudinal study of adolescent health. We surveyed adolescents about their team sports participation, other extracurricular physical activity, active commuting, physical education, recreational activity for fun, screen time, diet quality, and demographics. Overweight/obesity (BMI for age ≥ 85th percentile) and obesity (BMI for age ≥ 95 percentile) were based on self-reported height and weight. RESULTS: Overall, 29.0% (n = 498) of the sample was overweight/obese and 13.0% (n = 223) were obese. After adjustments, sports team participation was inversely related to overweight/obesity (relative risk [RR] = 0.73 [95% confidence interval (CI): 0.61, 0.87] for >2 sports teams versus 0) and obesity (RR = 0.61 [95% CI: 0.45, 0.81] for >2 sports teams versus 0). Additionally, active commuting to school was inversely related to obesity (RR = 0.67 [95% CI: 0.45, 0.99] for >3.5 days per week versus 0). Attributable risk estimates suggest obesity prevalence would decrease by 26.1% (95% CI: 9.4%, 42.8%) if all adolescents played on 2 sports teams per year and by 22.1% (95% CI: 0.1%, 43.3%) if all adolescents walked/biked to school at least 4 days per week. CONCLUSIONS: Team sport participation had the strongest and most consistent inverse association with weight status. Active commuting to school may reduce the risk of obesity, but not necessarily overweight, and should be studied further. Obesity prevention programs should consider strategies to increase team sport participation among all students. PMID:22802608
Cooperative Learning in Organic II. Increased Retention on a Commuter Campus
NASA Astrophysics Data System (ADS)
Hagen, James P.
2000-11-01
Modest use of cooperative learning techniques combined with extensive class notes produced a significant increase in retention for the second semester of organic chemistry on a commuter campus. The cooperative learning techniques included group testing, think-write-compare problems, and muddiest point essays. The first group take-home quiz must be carefully constructed and persuasively introduced to the class. An example is given. The increase in retention did not decrease class performance on standardized ACS exams, which was above the norms. Anecdotal student response to these techniques was largely positive. Student evaluation of instructor teaching improved modestly.
[New artificial lung respiration apparatuses for anesthesia and design of gas flow commutators].
Reĭderman, E N; Sterlin, Iu G; Trushin, A I; Maiakov, A A; Nemirovskiĭ, S B; Tsvik, A I
2005-01-01
The principles of action of new anesthetic devices and apparatuses for mechanical lung ventilation (MLV) including alternate-flow inhalation generators designed in recent time in VNIIMP-VITA, Ltd. are considered. According to the type of drive, these apparatuses fall into groups of devices with pneumatic drive (Diana) and electric drive (Elan). New technological approaches to design of gas flow commutators for pneumatic drive and respiratory contours of MLV apparatuses are discussed. The design of a new source of stable pneumatic signals providing reliable operation of the control valves of the inhalation and exhalation contours of electrically driven apparatuses. This source allows necessary MLV modes to be implemented during anesthesia. PMID:16491662
The Langley turbo-prop commuter design: A complete project description
NASA Technical Reports Server (NTRS)
Buttram, Greg; Horton, Keith; Keeter, Tim; Millhouse, Paul; Newberry, Kelli; Obyrne, Brian
1991-01-01
The primary objective of this project was to propose and prove the possibility of a new, advanced technology commuter aircraft design. Among the specifications were short to medium range capabilities, low seat per mile cost, fuel efficiency, and passenger comfort. Based on market evaluation, we found that the optimum size for new regional aircraft is around 50 passengers; we have designed our aircraft for this capacity. Turboprop engines provide substantial reductions in operating costs due to lower fuel consumption. We have therefore chosen an advanced turboprop engine. Composite materials, while more expensive to purchase and manufacture, result in decreased costs later through weight savings and ease of replacement.
Sagnac interferometry as a probe to the commutation relation of a macroscopic quantum mirror
Yang Ran; Gong Xuefei; Pei Shouyong; Luo Ziren; Lau, Y. K.
2010-09-15
Single photon Sagnac interferometry as a probe to macroscopic quantum mechanics is considered at the theoretical level. For a freely moving macroscopic quantum mirror susceptible to radiation pressure force inside a Sagnac interferometer, a careful analysis of the input-output relation reveals that the particle spectrum readout at the bright and dark ports encode information concerning the noncommutativity of position and momentum of the macroscopic mirror. A feasible experimental scheme to probe the commutation relation of a macroscopic quantum mirror is outlined to explore the possible frontier between classical and quantum regimes. In the Appendix, the case of Michelson interferometry as a feasible probe is also sketched.
On linear groups of degree 2 over a finite commutative ring
NASA Astrophysics Data System (ADS)
Bashkirov, Evgenii L.; Eser, Hasan
2014-08-01
Let p > 3 be a prime number and Fp be a field of p elements. Let K be a commutative and associative ring obtained by adjoining to Fp an element α such that α satisfies a polynomial over Fp and a polynomial of the least degree whose root is α can be written as a product of distinct polynomials irreducible over Fp. We prove that the special linear group SL2(K) is generated by two elementary transvections (1 1 0 1), (1 0 α 1).
Commuter exposure to aromatic VOCs in public transportation modes in Hong Kong.
Lau, Wai-Lun; Chan, Lo-Yin
2003-06-01
This study investigated commuter exposure to aromatic volatile organic compounds (VOCs) in different commuting microenvironments. In Hong Kong, more than 90% of the local citizens rely on public transport facilities in their daily commutes. During five winter months in late 2001 and early 2002, in-vehicle monitoring was performed in nine popular public transportation modes: tram, public light bus, air-conditioned bus, non-air-conditioned bus, taxi, ferry and three railway systems (Mass Transit Railway-MTR, Kowloon-Canton Railway-KCR and Light Rail Transit-LRT). These transports were grouped into three categories: railway transport, roadway transport and marine transport. Air samples of benzene, toluene, ethylbenzene and m/p/o-xylene were collected by canisters and analysed by gas chromatography and mass selective detector technique. Results indicated that the in-vehicle VOC exposure levels were greatly influenced by the mode of transport. For benzene, mean concentration ranged from 4.8 to 6.1 microg x m(-3) in roadway transports, 3.0-3.8 microg x m(-3) in railway transports and it was 2.1 microg x m(-3) in ferry. Regardless of the results in MTR and air-conditioned buses, the VOC levels in roadway transport were the highest and was followed by railway transport. The exposure levels in marine transport were the lowest. The TEX concentrations were found to be substantially higher in air-conditioned buses and MTR trains than in other transports, suggesting the existence of additional solvent-related sources in their vehicle interiors. Measurements in non-air-conditioned double deck vehicles indicate that there was slightly higher VOC levels in the lower deck than in the upper deck microenvironment. The average upper to lower deck exposure ratio ranged from 0.79 to 0.87 in trams and 0.78-0.83 in non-air-conditioned buses, depending on the compound of concern. The VOC exposure levels of public transport commuters in Hong Kong are far lower than those in most oversea
Design of a digital ride quality augmentation system for a commuter aircraft
NASA Technical Reports Server (NTRS)
Hammond, T. A.; Downing, D. R.; Amin, S. P.; Paduano, J.
1984-01-01
Commuter aircraft with low wing loading that operate at low altitudes are particularly susceptible to unwanted accelerations caused by atmospheric gusts. This paper describes the design and analysis of a longitudinal digital Ride Quality Augmentation System (RQAS). The RQAS designs were conducted for a Cessna 402B aircraft using the flaps and the elevator as the control surfaces. The designs are generated using linear quadratic Gaussian theory and analyzed in both the time and frequency domains. Nominal designs are presented at five flight conditions that cover a total mission. Trade-off studies are conducted to investigate the effect of sample time, computational delay time, servo bandwidth and control power.
Classifying Finite-Dimensional C*-Algebras by Posets of Their Commutative C*-Subalgebras
NASA Astrophysics Data System (ADS)
Lindenhovius, A. J.
2015-12-01
We consider the functor {{C}} that to a unital C*-algebra A assigns the partial order set {{C}}(A) of its commutative C*-subalgebras ordered by inclusion. We investigate how some C*-algebraic properties translate under the action of {C} to order-theoretical properties. In particular, we show that A is finite dimensional if and only {C}(A) satisfies certain chain conditions. We eventually show that if A and B are C*-algebras such that A is finite dimensional and {C}(A) and {C}(B) are order isomorphic, then A and B must be *-isomorphic.
Reducibility of invertible tuples to the principal component in commutative Banach algebras
NASA Astrophysics Data System (ADS)
Mortini, Raymond; Rupp, Rudolf
2015-10-01
Let A be a complex, commutative unital Banach algebra. We introduce two notions of exponential reducibility of Banach algebra tuples and present an analogue to the Corach-Suárez result on the connection between reducibility in A and in C(M(A)). Our methods are of an analytical nature. Necessary and sufficient geometric/topological conditions are given for reducibility (respectively reducibility to the principal component of Un(A)) whenever the spectrum of A is homeomorphic to a subset of {C}n.
Evaluation of a workplace intervention to promote commuter cycling: A RE-AIM analysis
2013-01-01
Background Originating from the interdisciplinary collaboration between public health and the transportation field a workplace intervention to promote commuter cycling, ‘Bike to Work: cyclists are rewarded’, was implemented. The intervention consisted of two cycling contests, an online loyalty program based on earning ‘cycling points’ and the dissemination of information through folders, newsletters, posters and a website. The study purpose was to evaluate the dissemination efforts of the program and to gain insights in whether free participation could persuade small and middle-sized companies to sign up. Methods The RE-AIM framework was used to guide the evaluation. Two months after the start of the intervention a questionnaire was send to 4880 employees. At the end of the intervention each company contact person (n = 12) was interviewed to obtain information on adoption, implementation and maintenance. Comparison analyses between employees aware and unaware of the program were conducted using independent-samples t-tests for quantitative data and chi-square tests for qualitative data. Difference in commuter cycling frequency was assessed using an ANOVA test. Non-parametric tests were used for the comparison analyses between the adopting and non-adopting companies. Results In total seven of the twelve participating companies adopted the program and all adopting companies implemented all intervention components. No significant differences were found in the mean number of employees (p = 0.15) or in the type of business sector (p = 0.92) between adopting and non-adopting companies. Five out of seven companies had the intention to continue the program. At the individual level, a project awareness of 65% was found. Employees aware of the program had a significantly more positive attitude towards cycling and reported significantly more commuter cycling than those unaware of the program (both p < 0.001). Participation was mainly because of health
On linear groups of degree 2 over a finite commutative ring
Bashkirov, Evgenii L.; Eser, Hasan
2014-08-20
Let p > 3 be a prime number and F{sub p} be a field of p elements. Let K be a commutative and associative ring obtained by adjoining to F{sub p} an element α such that α satisfies a polynomial over F{sub p} and a polynomial of the least degree whose root is α can be written as a product of distinct polynomials irreducible over F{sub p}. We prove that the special linear group SL{sub 2}(K) is generated by two elementary transvections ( (table) ), ( (table) )
NASA Astrophysics Data System (ADS)
Krsolarlak, Ilona
We analyze a certain class of von Neumann algebras generated by selfadjoint elements , for satisfying the general commutation relations:
NASA Astrophysics Data System (ADS)
Niwa, Yuta; Akiyama, Yuji; Naruta, Tomokazu
We carried out FEM simulations for modeling ultra-high-speed universal motors by using the state function method and analyzed the phenomenon of commutator sparking, the characteristics of the air gap surface, and the contact condition or contact resistance of the brushes and commutator bars. Thus, we could quantitatively analyze commutator sparking and investigate the configuration of the iron core. The results of FEM analysis were used to develop a model for predicting the configuration of the iron core and for estimating the electromotive force generated by the transformer, armature reaction field, spark voltage, contact resistance between the rotating brushes, and changes in the gap permeance. The results of our simulation were experimental results. This confirmed the validity of our analysis method. Thus, an ultra-high-speed, high-capacity of 1.5kw motor rotating at 30,000rpm can be designed for use in vacuum cleaners.
Liu, Wen-Te; Ma, Chih-Ming; Liu, I-Jung; Han, Bor-Cheng; Chuang, Hsiao-Chi; Chuang, Kai-Jen
2015-05-01
The association between traffic-related air pollution and adverse cardiovascular effects has been well documented; however, little is known about whether different commuting modes can modify the effects of air pollution on the cardiovascular system in human subjects in urban areas with heavy traffic. We recruited 120 young, healthy subjects in Taipei, Taiwan. Each participant was classified with different commuting modes according to his/her own commuting style. Three repeated measurements of heart rate variability (HRV) indices {standard deviation of NN intervals (SDNN) and the square root of the mean of the sum of the squares of differences between adjacent NN intervals (r-MSSD)}, particulate matter with an aerodynamic diameter ≤ 2.5 μm (PM2.5), temperature, humidity and noise level were conducted for each subject during 1-h morning commutes (0900-1000 h) in four different commuting modes, including an electrically powered subway, a gas-powered bus, a gasoline-powered car, and walking. Linear mixed-effects models were used to investigate the association of PM2.5 with HRV indices. The results showed that decreases in the HRV indices were associated with increased levels of PM2.5. The personal exposure levels to PM2.5 were the highest in the walking mode. The effects of PM2.5 on cardiovascular endpoints were the lowest in the subway mode compared to the effects in the walking mode. The participants in the car and bus modes had reduced effects on their cardiovascular endpoints compared to the participants in the walking mode. We concluded that traffic-related PM2.5 is associated with autonomic alteration. Commuting modes can modify the effects of PM2.5 on HRV indices among young, healthy subjects. PMID:25638696
Kramer, Michael R; Rosenberg, Eli S; Sanchez, Travis H; Reed, Landon; Sullivan, Patrick S
2015-01-01
Background Travel-related barriers to human immunodeficiency virus (HIV) care, such as commute time and mode of transportation, have been reported in the United States. Objective The objective of the study was to investigate the association between public transportation use and HIV care attendance among a convenience sample of Atlanta-based, HIV-positive men who have sex with men (MSM), evaluate differences across regions of residence, and estimate the relationship between travel distance and time by mode of transportation taken to attend appointments. Methods We used Poisson regression to estimate the association between use of public transportation to attend HIV-related medical visits and frequency of care attendance over the previous 12 months. The relationship between travel distance and commute time was estimated using linear regression. Kriging was used to interpolate commute time to visually examine geographic differences in commuting patterns in relation to access to public transportation and population-based estimates of household vehicle ownership. Results Using public transportation was associated with lower rates of HIV care attendance compared to using private transportation, but only in south Atlanta (south: aRR: 0.75, 95% CI 0.56, 1.0, north: aRR: 0.90, 95% CI 0.71, 1.1). Participants living in south Atlanta were more likely to have longer commute times associated with attending HIV visits, have greater access to public transportation, and may live in areas with low vehicle ownership. A majority of attended HIV providers were located in north and central Atlanta, despite there being participants living all across the city. Estimated commute times per mile traveled were three times as high among public transit users compared to private transportation users. Conclusions Improving local public transit and implementing use of mobile clinics could help address travel-related barriers to HIV care. PMID:27227128
Structure of Quark--Lepton Generation and Generalised Canonical Commutation Relations
NASA Astrophysics Data System (ADS)
Zenczykowski, P.
2007-08-01
Dirac-like linearisation of x2+p2 with noncommuting position and momentum variables leads to the representation of the standard U(1)otimes SU(3) symmetry of the three-dimensional harmonic oscillator in the relevant Clifford algebra and the emergence of a formula which we previously proposed to identify with the Gell-Mann-Nishijima-Glashow relation between charge, third component of weak isospin and weak hypercharge. This matrix representation exhibits features not present in the standard treatment of harmonic oscillator. We show that these features, strictly corresponding to the structure of a single quark-lepton generation in the Standard Model, may be understood from the point of view of specific O(6) phase-space transformations, which go beyond U(1)otimes SU(3), and modify standard canonical commutation relations. It is demonstrated that the whole structure of a single quark-lepton generation corresponds to assuming that the imaginary unit appearing in the canonical commutation relations may acquire an additional ``+'' or ``-'' sign separately for each of the three directions.
van Hooff, Madelon L M
2015-04-01
Sufficient recovery after daily effort expenditure at work is important to protect employee health and well-being. However, the role of commuting in the daily effort-recovery process is still not very well understood. The present study aimed to advance insight in this respect by examining if relaxation, detachment, mastery and stressful delays experienced during the commute from work to home affect employees' recovery status after returning home from work and at the end of the evening. Daily job demands were expected to moderate these effects. Serenity and (low) anxiety were included as indicators of employees' recovery status. Data were collected by means of a 5-day daily diary study (three measurements daily) among 76 participants from various industries. Multilevel analyses showed that relaxation was positively and stressful delays were negatively related to employees' recovery status after returning home from work but not to indicators of recovery at the end of the evening. For detachment, similar relations were found but only on days with high job demands. Mastery was not related to employees' recovery status. These findings enhance our insight in the daily effort-recovery cycle and underline the importance of promoting detachment (on demanding workdays) and relaxation on the way home from work. PMID:24124028
The green valley: the use of mobile narratives for reducing stress in commuters.
Grassi, Alessandra; Gaggioli, Andrea; Riva, Giuseppe
2009-04-01
New technologies have influenced communication and interaction among people, enabling them to overcome face-to-face limitations and eliminating the need for persons in a communicative relationship to be in the same place at the same time. This project aimed to test the effectiveness of mobile phone usage applied to emotion induction. The authors wanted to check whether or not mobile narratives supported by multimedia mobile phones can enhance relaxation and reduce anxiety in a sample of commuters. The project sample consisted of 120 commuters, college students aged 20 to 25 years. The sample was randomly assigned into four conditions: the Vidnar group experienced the mobile narrative on a mobile phone during their daily train trip; the Nonar group experienced only video content proposed on a mobile phone; the MP3 group experienced only the audio content proposed on an MP3 player; and the Control group provided a no-intervention condition. The study measured participants' emotional state (State-Trait Anxiety Inventory [STAI] State questionnaire), trait (STAI Trait questionnaire, Generalized Self-Efficacy Scale), and sense of presence (Slater-Usoh-Steed Questionnaire [UCL-SUS] and the International Test Commission-Sense of Presence Inventory [ITC-SOPI]) before and after the experience. The main results showed a significant decrease in anxiety level (p < 0.05, assessed by STAI State questionnaire) and an increase in relaxation level (p < 0.001) assessed by the Visual Analog Scale (VAS). No significant differences were found in other conditions. PMID:19275475
Code of Federal Regulations, 2010 CFR
2010-07-01
... disadvantages to using the commuted rate method for transporting HHG, PBP&E and temporary storage? 302-7.14... AND PROFESSIONAL BOOKS, PAPERS, AND EQUIPMENT (PBP&E) General Rules § 302-7.14 Are there any disadvantages to using the commuted rate method for transporting HHG, PBP&E and temporary storage? Yes....
Code of Federal Regulations, 2011 CFR
2011-04-01
... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary). 1.168(f)(8)-1T Section 1.168(f)(8)-1T Internal Revenue... information returns concerning qualified mass commuting vehicles (temporary). In general. Form 6793,...
Code of Federal Regulations, 2014 CFR
2014-04-01
... 26 Internal Revenue 2 2014-04-01 2014-04-01 false Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary). 1.168(f)(8)-1T Section 1.168(f)(8)-1T Internal Revenue... information returns concerning qualified mass commuting vehicles (temporary). In general. Form 6793,...
Code of Federal Regulations, 2012 CFR
2012-04-01
... 26 Internal Revenue 2 2012-04-01 2012-04-01 false Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary). 1.168(f)(8)-1T Section 1.168(f)(8)-1T Internal Revenue... information returns concerning qualified mass commuting vehicles (temporary). In general. Form 6793,...
Code of Federal Regulations, 2013 CFR
2013-04-01
... 26 Internal Revenue 2 2013-04-01 2013-04-01 false Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary). 1.168(f)(8)-1T Section 1.168(f)(8)-1T Internal Revenue... information returns concerning qualified mass commuting vehicles (temporary). In general. Form 6793,...
Code of Federal Regulations, 2010 CFR
2010-04-01
... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Safe-harbor lease information returns concerning qualified mass commuting vehicles (temporary). 1.168(f)(8)-1T Section 1.168(f)(8)-1T Internal Revenue... information returns concerning qualified mass commuting vehicles (temporary). In general. Form 6793,...
ERIC Educational Resources Information Center
Sessa, Frances M.
2005-01-01
Differences between residential and commuter first-year male college students were examined with respect to students' perceptions of the parent-child relationship and its influence on students' use of alcohol and marijuana. Fifty residential and 57 commuter students completed questionnaires to assess their perceptions of parenting and the…
Code of Federal Regulations, 2012 CFR
2012-01-01
... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false What is the difference between a contract or a rate tender and a commuted rate system? 102-117.225 Section 102-117.225 Public... What is the difference between a contract or a rate tender and a commuted rate system? (a) Under...
Code of Federal Regulations, 2011 CFR
2011-01-01
... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false What is the difference between a contract or a rate tender and a commuted rate system? 102-117.225 Section 102-117.225 Public... What is the difference between a contract or a rate tender and a commuted rate system? (a) Under...
Code of Federal Regulations, 2014 CFR
2014-01-01
... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false What is the difference between a contract or a rate tender and a commuted rate system? 102-117.225 Section 102-117.225 Public... What is the difference between a contract or a rate tender and a commuted rate system? (a) Under...
Code of Federal Regulations, 2013 CFR
2013-07-01
... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false What is the difference between a contract or a rate tender and a commuted rate system? 102-117.225 Section 102-117.225 Public... What is the difference between a contract or a rate tender and a commuted rate system? (a) Under...
Code of Federal Regulations, 2010 CFR
2010-07-01
... between a contract or a rate tender and a commuted rate system? 102-117.225 Section 102-117.225 Public... What is the difference between a contract or a rate tender and a commuted rate system? (a) Under a contract or a rate tender, the agency prepares the bill of lading and books the shipment. The agency is...
Characterizing the range of children's air pollutant exposure during school bus commutes.
Sabin, Lisa D; Behrentz, Eduardo; Winer, Arthur M; Jeong, Seong; Fitz, Dennis R; Pankratz, David V; Colome, Steven D; Fruin, Scott A
2005-09-01
Real-time and integrated measurements of gaseous and particulate pollutants were conducted inside five conventional diesel school buses, a diesel bus with a particulate trap, and a bus powered by compressed natural gas (CNG) to determine the range of children's exposures during school bus commutes and conditions leading to high exposures. Measurements were made during 24 morning and afternoon commutes on two Los Angeles Unified School District bus routes from South to West Los Angeles, with seven additional runs on a rural/suburban route, and three runs to test the effect of window position. For these commutes, the mean concentrations of diesel vehicle-related pollutants ranged from 0.9 to 19 microg/m(3) for black carbon, 23 to 400 ng/m(3) for particle-bound polycyclic aromatic hydrocarbon (PB-PAH), and 64 to 220 microg/m(3) for NO(2). Concentrations of benzene and formaldehyde ranged from 0.1 to 11 microg/m(3) and 0.3 to 5 microg/m(3), respectively. The highest real-time concentrations of black carbon, PB-PAH and NO(2) inside the buses were 52 microg/m(3), 2000 ng/m(3), and 370 microg/m(3), respectively. These pollutants were significantly higher inside conventional diesel buses compared to the CNG bus, although formaldehyde concentrations were higher inside the CNG bus. Mean black carbon, PB-PAH, benzene and formaldehyde concentrations were higher when the windows were closed, compared with partially open, in part, due to intrusion of the bus's own exhaust into the bus cabin, as demonstrated through the use of a tracer gas added to each bus's exhaust. These same pollutants tended to be higher on urban routes compared to the rural/suburban route, and substantially higher inside the bus cabins compared to ambient measurements. Mean concentrations of pollutants with substantial secondary formation, such as PM(2.5), showed smaller differences between open and closed window conditions and between bus routes. Type of bus, traffic congestion levels, and encounters with
NASA Astrophysics Data System (ADS)
Aissaoui, H.; Mebarki, N.; Bouhalouf, H.
2010-10-01
An FRW like cosmological model in the non commutative Seiberg-Witten space-time is proposed. The pure NCG dynamical apparent horizon and Hawking temperature are obtained and explicit expressions of the scale factor, Hubble and deceleration parameters are derived. The accelerated expansion of the universe scenario is also discussed.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false What documentation is required to receive an advance under the commuted rate method? 302-7.106 Section 302-7.106 Public Contracts and Property Management Federal Travel Regulation System RELOCATION ALLOWANCES TRANSPORTATION AND STORAGE OF PROPERTY 7-TRANSPORTATION...
ERIC Educational Resources Information Center
Bukowski, Joseph E.
Focusing on freshmen commuter students and freshmen dormitory students at Johnson and Wales College, general characteristics and academic achievement were measured. General entrance characteristics included student age, College Entrance Examination Board scores and high school rank. Academic achievement was measured in terms of student grades in…
ERIC Educational Resources Information Center
Galladian, Carol
2013-01-01
The purpose of this quantitative ex post facto study was to provide a description of the student engagement of commuter students attending a large urban public university located in a mid-Atlantic state using the five National Survey of Student Engagement (NSSE) benchmarks of student engagement. In addition, the study examined the relationship…
Technology Transfer Automated Retrieval System (TEKTRAN)
The Walking School Bus (WSB) pilot program was evaluated to determine the impact on student’s Active Commuting to School (ACS) and moderate-to vigorous- physical activity (MVPA). We conducted a randomized controlled trial in 8 low income, elementary schools in Houston, TX, USA. Students (n=149) wer...
Technology Transfer Automated Retrieval System (TEKTRAN)
Children's active commuting to school, i.e. walking or cycling to school, was associated with greater moderate-to-vigorous physical activity, although studies among ethnic minorities are sparse. Among a low-income, ethnic minority sample of fourth grade students from eight public schools, we examine...
ERIC Educational Resources Information Center
Lurvey, Phyllis C.
2011-01-01
A volunteer sample of 16 Hispanic first-generation commuter college students, 9 women and 7 men, 18-30 years of age, attending a private college in the Northeast, were interviewed about their first-year college experience, with an emphasis on issues related to cultural capital and habitus. Five aspects of cultural capital were of interest:…
Code of Federal Regulations, 2010 CFR
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Issue of type certificate: normal, utility, acrobatic, commuter, and transport category aircraft; manned free balloons; special classes of aircraft; aircraft engines; propellers. 21.21 Section 21.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION...
49 CFR 37.49 - Designation of responsible person(s) for intercity and commuter rail stations.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 1 2014-10-01 2014-10-01 false Designation of responsible person(s) for intercity... Designation of responsible person(s) for intercity and commuter rail stations. (a) The responsible person(s... more than fifty percent of which is owned by a public entity, the public entity is the...
49 CFR 37.49 - Designation of responsible person(s) for intercity and commuter rail stations.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 1 2010-10-01 2010-10-01 false Designation of responsible person(s) for intercity... Designation of responsible person(s) for intercity and commuter rail stations. (a) The responsible person(s... more than fifty percent of which is owned by a public entity, the public entity is the...
49 CFR 37.49 - Designation of responsible person(s) for intercity and commuter rail stations.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 1 2013-10-01 2013-10-01 false Designation of responsible person(s) for intercity... Designation of responsible person(s) for intercity and commuter rail stations. (a) The responsible person(s... more than fifty percent of which is owned by a public entity, the public entity is the...
49 CFR 37.49 - Designation of responsible person(s) for intercity and commuter rail stations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 1 2011-10-01 2011-10-01 false Designation of responsible person(s) for intercity... Designation of responsible person(s) for intercity and commuter rail stations. (a) The responsible person(s... more than fifty percent of which is owned by a public entity, the public entity is the...
49 CFR 37.49 - Designation of responsible person(s) for intercity and commuter rail stations.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 1 2012-10-01 2012-10-01 false Designation of responsible person(s) for intercity and commuter rail stations. 37.49 Section 37.49 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Transportation Facilities § 37.49 Designation of responsible person(s)...
Morabia, Alfredo; Zhang, Fang Fang; Kappil, Maya A.; Flory, Janine; Mirer, Frank E; Santella, Regina M.; Wolff, Mary; Markowitz, Steven B
2013-01-01
Background and Aims Commuting by public transportation (PT) entails more physical activity and energy expenditure than by cars, but its biologic consequences are unknown. Methods In 2009-2010, we randomly sampled New York adults, usually commuting either by car (n=79) or PT (n=101). Measures comprised diet and physical activity questionnaires, weight and height, white blood cell (WBC) count, C reactive protein, (CRP) gene-specific methylation (IL-6), and global genomic DNA methylation (LINE-1 methylation). Results Compared to the 101 PT commuters, the 79 car drivers were about 9 years older, 2 kg/m2 heavier, more often non-Hispanic whites, and ate more fruits and more meats. The 2005 guidelines for physical activity were met by more car drivers than PT users (78.5% vs. 65.0%). There were no differences in median levels of CRP (car vs. PT: 0.6 vs. 0.5 mg/dl), mean levels of WBC (car vs. PT: 6.7 vs. 6.5 cells/mm3), LINE-1 methylation (car vs. PT: 78.0% vs. 78.3%), and promoter methylation of IL-6 (car vs. PT: 56.1% vs. 58.0%). Conclusions PT users were younger and lighter than car drivers, but their commute mode did not translate into a lower inflammatory response or a higher DNA methylation, maybe because, overall, car drivers were more physically active. PMID:22313796
Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-23
... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Rugby Aviation LLC D/B/A Northwest Sky Ferry for Commuter Air... persons to show cause why it should not issue an order finding Rugby ] Aviation, LLC d/b/a Northwest...
Code of Federal Regulations, 2011 CFR
2011-01-01
...; aircraft engines; propellers. 21.21 Section 21.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.21 Issue of type certificate: normal, utility, acrobatic, commuter, and transport category...
Code of Federal Regulations, 2014 CFR
2014-01-01
...; aircraft engines; propellers. 21.21 Section 21.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.21 Issue of type certificate: normal, utility, acrobatic, commuter, and transport category...
Code of Federal Regulations, 2012 CFR
2012-01-01
...; aircraft engines; propellers. 21.21 Section 21.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.21 Issue of type certificate: normal, utility, acrobatic, commuter, and transport category...
Code of Federal Regulations, 2013 CFR
2013-01-01
...; aircraft engines; propellers. 21.21 Section 21.21 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Type Certificates § 21.21 Issue of type certificate: normal, utility, acrobatic, commuter, and transport category...
Dygrýn, Jan; Mitáš, Josef; Gába, Aleš; Rubín, Lukáš; Frömel, Karel
2015-01-01
Active commuting (AC) to school represents a great opportunity to incorporate walking or cycling into adolescents’ everyday routine. The objective of the study was to describe changes in AC in Czech adolescents across a 10-year period in different built environments. Data from the 2001 and 2011 Czech Census of Population and Housing were used to examine the mode of transportation taken to school in 6236 adolescents. Changes in AC over time were analyzed for low and high walkable areas separately in two Czech regional cities, Olomouc and Hradec Králové. Between 2001 and 2011, the proportion of adolescents actively commuting to school decreased by 47%, from an absolute rate of 49.1% to 26%. The proportion of active commuters fell in low walkable areas by 61% and in high walkable areas by 39%. The results indicated that adolescents in 2011 were 2.7 times less (OR = 0.365, p < 0.001) likely to actively commute than in 2001. The AC behavior in Czech adolescents has a negative tendency to replicate travel-to-school patterns in adolescents previously described in more developed countries. The findings might serve as a recommendation for municipal policy. PMID:26501304
Code of Federal Regulations, 2010 CFR
2010-01-01
... operations, management, or ownership, including changes that may affect the air carrier's citizenship, shall... undergoing or proposing to undergo substantial change in operations, ownership, or management. 204.5 Section..., ownership, or management. (a) A certificated or commuter air carrier proposing a substantial change...
ERIC Educational Resources Information Center
Gutiérrez-Zornoza, Myriam; Sánchez-López, Mairena; García-Hermoso, Antonio; González-García, Alberto; Chillón, Palma; Martínez-Vizcaíno, Vicente
2015-01-01
Purpose: The aim of this study was to examine (a) whether distance from home to school is a determinant of active commuting to school (ACS), (b) the relationship between distance from home to heavily used facilities (school, green spaces, and sports facilities) and the weight status and cardiometabolic risk categories, and (c) whether ACS has a…
Sherrouse, Benson C.; Hester, David J.
2008-01-01
The Multi-Hazards Demonstration Project (MHDP) is a collaboration between the U.S. Geological Survey (USGS) and various partners from the public and private sectors and academia, meant to improve Southern California's resiliency to natural hazards (Jones and others, 2007). In support of the MHDP objectives, the ShakeOut Scenario was developed. It describes a magnitude 7.8 (M7.8) earthquake along the southernmost 300 kilometers (200 miles) of the San Andreas Fault, identified by geoscientists as a plausible event that will cause moderate to strong shaking over much of the eight-county (Imperial, Kern, Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Ventura) Southern California region (Jones and others, 2008). This report uses selected datasets from the U.S. Census Bureau and the State of California's Employment Development Department to develop preliminary estimates of the number and spatial distribution of commuters who cross the San Andreas Fault and to characterize these commuters by the industries in which they work and their total earnings. The analysis concerns the relative exposure of the region's economy to the effects of the earthquake as described by the location, volume, and earnings of those commuters who work in each of the region's economic sectors. It is anticipated that damage to transportation corridors traversing the fault would lead to at least short-term disruptions in the ability of commuters to travel between their places of residence and work.
Dygrýn, Jan; Mitáš, Josef; Gába, Aleš; Rubín, Lukáš; Frömel, Karel
2015-10-01
Active commuting (AC) to school represents a great opportunity to incorporate walking or cycling into adolescents' everyday routine. The objective of the study was to describe changes in AC in Czech adolescents across a 10-year period in different built environments. Data from the 2001 and 2011 Czech Census of Population and Housing were used to examine the mode of transportation taken to school in 6236 adolescents. Changes in AC over time were analyzed for low and high walkable areas separately in two Czech regional cities, Olomouc and Hradec Králové. Between 2001 and 2011, the proportion of adolescents actively commuting to school decreased by 47%, from an absolute rate of 49.1% to 26%. The proportion of active commuters fell in low walkable areas by 61% and in high walkable areas by 39%. The results indicated that adolescents in 2011 were 2.7 times less (OR = 0.365, p < 0.001) likely to actively commute than in 2001. The AC behavior in Czech adolescents has a negative tendency to replicate travel-to-school patterns in adolescents previously described in more developed countries. The findings might serve as a recommendation for municipal policy. PMID:26501304
Federal Register 2010, 2011, 2012, 2013, 2014
2012-06-08
... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Sun Air Express, LLC, d/b/a Sun Air International for Commuter... to show cause why it should not issue an order finding Sun Air Express, LLC d/b/a Sun...
Yeh, Fung-Huei; Yang, Chung-Chieh
2014-12-01
This study proposed a new information and commutation technology assisted blind telephone interview (ICT-ABTI) system to help visually impaired people to do telephone interview jobs as normal sighted people and create more diverse employment opportunities for them. The study also used an ABAB design to assess the system with seven visually impaired people. As the results, they can accomplish 3070 effective telephone interviews per month independently. The results also show that working performance of the visually impaired can be improved effectively with appropriate design of operation working flow and accessible software. The visually impaired become productive, lucrative, and self-sufficient by using ICT-ABTI system to do telephone interview jobs. The results were also shared through the APEC Digital Opportunity Center platform to help visually impaired in Philippines, Malaysia and China. PMID:25209925
NASA Astrophysics Data System (ADS)
Partanen, Mikko; Häyrynen, Teppo; Tulkki, Jukka; Oksanen, Jani
2015-09-01
We have recently developed a quantized fluctuational electrodynamics (QFED) formalism to describe the quantum aspects of local thermal balance formation and to formulate the electromagnetic field ladder operators so that they no longer exhibit the anomalies reported for resonant structures. Here we show how the QFED can be used to resolve between the left and right propagating fields to bridge the QFED and the quantum optical input-output relations commonly used to describe selected quantum aspects of resonators. The generalized model introduces a density of states concept describing interference effects, which is instrumental in allowing an unambiguous separation of the fields and related quantum operators into left and right propagating parts. In addition to providing insight on the quantum treatment of interference, our results also provide the conclusive resolution of the long-standing enigma of the anomalous commutation relations of partially confined propagating fields.
Presentation of Class 1 designs for a family of commuter airplanes
NASA Technical Reports Server (NTRS)
Creighton, Tom; Dragush, George; Hendrich, Louis; Hensley, Doug; Morgan, Louise; Oxendine, Charles; Remen, John; Robinson, Terry; Russell, Mark; Swift, Jerry
1986-01-01
The Class 1 configuration designs of a family of commuter aircraft are presented. The proposed aircraft will have a capacity of from 25 to 100 passengers. They are to have the following common features: (1) 2 aft fuselage mounted engines; (2) a low wing; (3) a T-tail type empennage; and (4) a tricycle type landing gear. A family concept is introduced to achieve structural, systems and handling quality commonality throughout. Implementing commonality can substantially reduce manufacturing and production costs. By achieving common system designs, maintenance costs can be reduced by permitting airlines to stock a smaller inventory of spares. Therefore, the higher degree of commonality, the lower the direct operating and life cycle costs. The attempt to implement some of the commonality requirements has caused configuration design problems, i.e., the twin-body concept was introduced. Design data are compared to existing aircraft, and the extent of structural, systems and handling qualities achieved are reviewed.
Jones, R.A.; Sims, T.R. ); Imece, A.F. )
1990-12-01
One of the major concerns of utilities about the impact of dispersed PV generation is islanding or the continued operation of a portion of the system, after it has been disconnected from the utility. This paper presents a summary of the results of a research project on the islanding potential of a Teslaco self-commutated static power converter (SPC). This project included computer simulations, laboratory testing, and field testing. Laboratory and field tests verified that the SPC model developed for computer simulations accurately predicts SPC islanding performance under a variety of system conditions. Furthermore, the impact of a number of system parameters on the islanding potential are presented. These include the mismatch between load and generation within the island, the type of load within the island, the number of SPCs within the island, load variations, and solar insolation variations.
Development of ATC for High Speed and High Density Commuter Line
NASA Astrophysics Data System (ADS)
Okutani, Tamio; Nakamura, Nobuyuki; Araki, Hisato; Irie, Shouji; Osa, Hiroki; Sano, Minoru; Ikeda, Keigo; Ozawa, Hiroyuki
A new ATC (Automatic Train Control) system has been developed with solutions to realize short train headway by assured braking utilizing digital data transmission via rails; the digital data for the ATP (Automatic Train Protection) function; and to achieve EMC features for both AC and DC sections. The DC section is of the unprecedented DC traction power supply system utilizing IGBT PWM converter at all DC substations. Within the AC section, train traction force is controlled by PWM converter/inverters. The carrier frequencies of the digital data signals and chopping frequency of PWM traction power converters on-board are decided via spectral analysis of noise up to degraded mode cases of equipment. Developed system was equipped to the Tukuba Express Line, new commuter line of Tokyo metropolitan area, and opened since Aug. 2005.
Average-Case Complexity Versus Approximate Simulation of Commuting Quantum Computations.
Bremner, Michael J; Montanaro, Ashley; Shepherd, Dan J
2016-08-19
We use the class of commuting quantum computations known as IQP (instantaneous quantum polynomial time) to strengthen the conjecture that quantum computers are hard to simulate classically. We show that, if either of two plausible average-case hardness conjectures holds, then IQP computations are hard to simulate classically up to constant additive error. One conjecture relates to the hardness of estimating the complex-temperature partition function for random instances of the Ising model; the other concerns approximating the number of zeroes of random low-degree polynomials. We observe that both conjectures can be shown to be valid in the setting of worst-case complexity. We arrive at these conjectures by deriving spin-based generalizations of the boson sampling problem that avoid the so-called permanent anticoncentration conjecture. PMID:27588839
Efficient, Low-Cost Fan System Research for General Aviation and Commuter Aircraft
NASA Technical Reports Server (NTRS)
Merrill, G. L.
2003-01-01
This document reports research investigations into efficient, low-cost fan system concepts for high bypass turbofans for future general aviation and commuter aircraft. The research specifically addressed lower pressure ratio fans for good propulsive efficiencies in the 200 to 400 knot flight speed regime. Aerodynamic design analyses yielded predicted efficiency in area of 91 to 92 percent (adiabatic). Low-cost manufacturing studies yielded an aluminum blisk rotor and investment cast stator having lowest cost. Structural design analyses yielded a design having excellent vibratory characteristics and the ability to pass One- and Four-pound bird strikes satisfactorily. The low speed and low pressure fans of the study are estimated to have 24 to 30 EPNdB lower community noise levels than larger, high pressure ratio transonic fans.
Demonstration of Caterpillar C-10 dual-fuel engines in MCI 102DL3 commuter buses
2000-02-28
The purpose of this program was to demonstrate the Caterpillar C-10 Dual-Fuel Natural Gas (DFNG) engine in an over-the-road bus application. Three new Motor Coach Industries (MCI) 102DL3 buses, equipped with Caterpillar C-10 DFNG engines, and one bus, equipped with a Caterpillar C-10 diesel engine, were operated side by side on similar fixed-route revenue service for a 12-month demonstration period (February 1998 to January 1999). The buses were used as part of the Clean Air Express Commuter Bus Program in Santa Barbara County, California. The performance and reliability of the DFNG engines were similar to that of the diesel engine, but the emissions results were mixed.
NASA Technical Reports Server (NTRS)
Turk, M. A.; Zeiner, P. K.
1986-01-01
In connection with the significant advances made regarding the performance of larger gas turbines, challenges arise concerning the improvement of small gas turbine engines in the 250 to 1000 horsepower range. In response to these challenges, the NASA/Army-sponsored Small Engine Component Technology (SECT) study was undertaken with the objective to identify the engine cycle, configuration, and component technology requirements for the substantial performance improvements desired in year-2000 small gas turbine engines. In the context of this objective, an American turbine engine company evaluated engines for four year-2000 applications, including a rotorcraft, a commuter aircraft, a supersonic cruise missile, and an auxiliary power unit (APU). Attention is given to reference missions, reference engines, reference aircraft, year-2000 technology projections, cycle studies, advanced engine selections, and a technology evaluation.
Urban air quality comparison for bus, tram, subway and pedestrian commutes in Barcelona.
Moreno, Teresa; Reche, Cristina; Rivas, Ioar; Cruz Minguillón, Maria; Martins, Vânia; Vargas, Concepción; Buonanno, Giorgio; Parga, Jesus; Pandolfi, Marco; Brines, Mariola; Ealo, Marina; Sofia Fonseca, Ana; Amato, Fulvio; Sosa, Garay; Capdevila, Marta; de Miguel, Eladio; Querol, Xavier; Gibbons, Wes
2015-10-01
Access to detailed comparisons in air quality variations encountered when commuting through a city offers the urban traveller more informed choice on how to minimise personal exposure to inhalable pollutants. In this study we report on an experiment designed to compare atmospheric contaminants inhaled during bus, subway train, tram and walking journeys through the city of Barcelona. Average number concentrations of particles 10-300 nm in size, N, are lowest in the commute using subway trains (N<2.5×10(4) part. cm(-3)), higher during tram travel and suburban walking (2.5×10(4) cm(-3)
Naturalistic cycling study: identifying risk factors for on-road commuter cyclists.
Johnson, Marilyn; Charlton, Judith; Oxley, Jennifer; Newstead, Stuart
2010-01-01
The study aim was to identify risk factors for collisions/near-collisions involving on-road commuter cyclists and drivers. A naturalistic cycling study was conducted in Melbourne, Australia, with cyclists wearing helmet-mounted video cameras. Video recordings captured cyclists' perspective of the road and traffic behaviours including head checks, reactions and manoeuvres. The 100-car naturalistic driving study analysis technique was adapted for data analysis and events were classified by severity: collision, near-collision and incident. Participants were adult cyclists and each filmed 12 hours of commuter cycling trips over a 4-week period. In total, 127 hours and 38 minutes were analysed for 13 participants, 54 events were identified: 2 collisions, 6 near-collisions and 46 incidents. Prior to events, 88.9% of cyclists travelled in a safe/legal manner. Sideswipe was the most frequent event type (40.7%). Most events occurred at an intersection/intersection-related location (70.3%). The vehicle driver was judged at fault in the majority of events (87.0%) and no post-event driver reaction was observed (83.3%). Cross tabulations revealed significant associations between event severity and: cyclist reaction, cyclist post-event manoeuvre, pre-event driver behaviour, other vehicle involved, driver reaction, visual obstruction, cyclist head check (left), event type and vehicle location (p<0.05). Frequent head checks suggest cyclists had high situational awareness and their reactive behaviour to driver actions led to successful avoidance of collisions/near-collisions. Strategies to improve driver awareness of on-road cyclists and to indicate early before turning/changing lanes when sharing the roadway with cyclists are discussed. Findings will contribute to the development of effective countermeasures to reduce cyclist trauma. PMID:21050610
A review of commuter exposure to ultrafine particles and its health effects
NASA Astrophysics Data System (ADS)
Knibbs, Luke D.; Cole-Hunter, Tom; Morawska, Lidia
2011-05-01
Ultrafine particles (UFPs, <100 nm) are produced in large quantities by vehicular combustion and are implicated in causing several adverse human health effects. Recent work has suggested that a large proportion of daily UFP exposure may occur during commuting. However, the determinants, variability and transport mode-dependence of such exposure are not well-understood. The aim of this review was to address these knowledge gaps by distilling the results of 'in-transit' UFP exposure studies performed to-date, including studies of health effects. We identified 47 exposure studies performed across 6 transport modes: automobile, bicycle, bus, ferry, rail and walking. These encompassed approximately 3000 individual trips where UFP concentrations were measured. After weighting mean UFP concentrations by the number of trips in which they were collected, we found overall mean UFP concentrations of 3.4, 4.2, 4.5, 4.7, 4.9 and 5.7 × 10 4 particles cm -3 for the bicycle, bus, automobile, rail, walking and ferry modes, respectively. The mean concentration inside automobiles travelling through tunnels was 3.0 × 10 5 particles cm -3. While the mean concentrations were indicative of general trends, we found that the determinants of exposure (meteorology, traffic parameters, route, fuel type, exhaust treatment technologies, cabin ventilation, filtration, deposition, UFP penetration) exhibited marked variability and mode-dependence, such that it is not necessarily appropriate to rank modes in order of exposure without detailed consideration of these factors. Ten in-transit health effects studies have been conducted and their results indicate that UFP exposure during commuting can elicit acute effects in both healthy and health-compromised individuals. We suggest that future work should focus on further defining the contribution of in-transit UFP exposure to total UFP exposure, exploring its specific health effects and investigating exposures in the developing world.
Naturalistic Cycling Study: Identifying Risk Factors for On-Road Commuter Cyclists
Johnson, Marilyn; Charlton, Judith; Oxley, Jennifer; Newstead, Stuart
2010-01-01
The study aim was to identify risk factors for collisions/near-collisions involving on-road commuter cyclists and drivers. A naturalistic cycling study was conducted in Melbourne, Australia, with cyclists wearing helmet-mounted video cameras. Video recordings captured cyclists’ perspective of the road and traffic behaviours including head checks, reactions and manoeuvres. The 100-car naturalistic driving study analysis technique was adapted for data analysis and events were classified by severity: collision, near-collision and incident. Participants were adult cyclists and each filmed 12 hours of commuter cycling trips over a 4-week period. In total, 127 hours and 38 minutes were analysed for 13 participants, 54 events were identified: 2 collisions, 6 near-collisions and 46 incidents. Prior to events, 88.9% of cyclists travelled in a safe/legal manner. Sideswipe was the most frequent event type (40.7%). Most events occurred at an intersection/intersection-related location (70.3%). The vehicle driver was judged at fault in the majority of events (87.0%) and no post-event driver reaction was observed (83.3%). Cross tabulations revealed significant associations between event severity and: cyclist reaction, cyclist post-event manoeuvre, pre-event driver behaviour, other vehicle involved, driver reaction, visual obstruction, cyclist head check (left), event type and vehicle location (p<0.05). Frequent head checks suggest cyclists had high situational awareness and their reactive behaviour to driver actions led to successful avoidance of collisions/near-collisions. Strategies to improve driver awareness of on-road cyclists and to indicate early before turning/changing lanes when sharing the roadway with cyclists are discussed. Findings will contribute to the development of effective countermeasures to reduce cyclist trauma. PMID:21050610
Bikchentaev, A M
2008-04-30
It is proved that every skew-Hermitian element of any properly infinite von Neumann algebra can be represented in the form of a finite sum of commutators of projections in this algebra. A new commutation condition for projections in terms of their upper (lower) bound in the lattice of all projections of the algebra is obtained. For the full matrix algebra the set of operators with canonical trace zero is described in terms of finite sums of commutators of projections and the domain in which the trace is positive is described in terms of finite sums of pairwise products of projections. Applications to AF-algebras are obtained. Bibliography: 33 titles.
Low power consumption current transducer
NASA Technical Reports Server (NTRS)
Mclyman, W. T. (Inventor)
1989-01-01
A low power consumption current transducer utilizes a saturable core reactor which includes a pair of opposed gate windings and a control winding. The control winding of the saturable reactor is arranged to receive the current to be measured. A square wave generator is connected to the gate winding of the transformer connected across the square wave generator and the secondary connected in series with the gate windings of the reactor. A full wave rectifier is connected to the gate windings and a resistor is connected across the rectifier to provide a DC voltage to cross it representative of the current flow through the control winding. A DC power supply is provided to supply power to the square wave voltage source. A diode is connected between each end of the primary winding of the transformer and one polarity of the DC power supply to commutate the reactive current resulting from the counter emf generated in the reactor back to the DC supply to eliminate potentially damaging reactive voltage spikes which would otherwise appear at the output of the square wave generator and conserve energy.
Local and Far-Field Effects of Commuter Ferry Wake in New York Harbor: Implications for Mitigation
NASA Astrophysics Data System (ADS)
Fullerton, B.
2002-12-01
Anthropogenic sources of waves in New York Harbor have grown in recent years to the point that they are presently the dominant source of wave energy. Small fast commuter ferries account for the bulk of this growth. Between 1996 and present, fast-ferry traffic across the Hudson has seen an order of magnitude increase in both ferry crossings and ferry routes. Pressure time series recorders were co-located with profiling acoustic Doppler current, turbidity, and conductivity meters, deployed synoptically in strategic harbor locales for seven-day periods in summer and fall of 2002. Analysis of the sea-surface elevation time series revealed a semi-diurnal increase in wave energy coinciding with peak ferry use during morning and evening rush-hours. The measured wave energy levels during rush-hours was well above the wave energy levels measured overnight, when ferries were no longer in use. During rush-hours, the time-series of sea surface elevation appeared as a persistent background of waves with periods between 1.5 and 4.5 seconds containing intermittent, well-defined packets of high amplitude waves which appeared to be coincident with local ferry passage. The temporal pattern of sea-surface elevation throughout the weekday was repeated throughout the workweek. However, during weekends, the magnitude of the background wave energy level was approximately one half the magnitude of the energy level measured during any given workweek day. The amplitude of waves within the intermittent packets remained nearly constant for the entire week. The local, near-field effect of ferry traffic is visible in the sea surface elevation time series as intermittent packets, whereas the far-field effects, integrated harbor-wide, is seen as the background sea-state. The dual nature of the wave energy creates an implication for efforts attempting to mitigate the wave conditions. For conditions when the background sea-state is acceptable, small adjustments to individual ferry tracks and speeds
Personal exposure to black carbon during commuting in peak and off-peak hours in Shanghai.
Li, Bo; Lei, Xiao-ning; Xiu, Guang-li; Gao, Chi-yuan; Gao, Shuang; Qian, Ni-sheng
2015-08-15
A study on a commuter's exposure to black carbon (BC) in five different traffic modes (taxi, bus, subway, cycling and walking) was conducted in Xuhui District, Shanghai. A commuter's real-time exposure concentrations were recorded by MicroAeth AE51 BC monitors, and the average BC exposure concentration and inhalation dose were analyzed. Data collected by cyclist was applied to characterize the micro-variability in relation to traffic density and street topology. The distance to the traffic and the street topology as well as the volume of heavy diesel trucks were the dominant factors influencing the BC concentrations. In this study, a high variability of BC concentrations between streets and even within streets was observed, and also between days and hour of the day. The average BC exposure concentrations were 5.59±1.02 μg/m(3), 6.58±1.78 μg/m(3), 7.28±1.87 μg/m(3), 8.62±4.13 μg/m(3) and 9.43±2.89 μg/m(3) for walking, cycling, bus, taxi and subway trips, respectively. Exposure levels of in-vehicle microenvironments were 8.66±3.66 μg/m(3), 9.39±6.98 μg/m(3) and 10.96±2.72 μg/m(3) for bus, taxi and subway, respectively. While inhalation doses were 0.68±0.33 μg, 0.95±0.29 μg, 1.36±0.37 μg, 1.50±0.39 μg and 1.58±0.29 μg for taxi, subway, cycling, bus and walking, respectively. BC exposure level of walking was the lowest among all the traffic modes, but its inhalation dose was the highest. PMID:25909267
Ocular injuries in survivors of improvised explosive devices (IED) in commuter trains
Mehta, Salil; Agarwal, Vinay; Jiandani, Prakash
2007-01-01
Background Ocular injuries are common in survivors of terror incidents that involve the use of explosive materials. These explosives are commonly of a High Explosive type (HE) and may be fashioned into improvised explosive devices (IED) that incorporate additional materials to maximise trauma and injuries. Serial IED explosions have occurred in commuter trains in several cities including London and Madrid but data on ocular injuries is limited. We report the ocular injuries of the survivors of a series of IED explosions in crowded commuter trains. Methods 28 patients (56 eyes, 28 male, ages ranging from 22 to 52 years (mean 35.27 years) were screened in the triage area or the Intensive Care Unit (ICU). Testing included bedside visual acuity testing, torchlight examination of the anterior segment and dilated (or if necessary, undilated) fundus examination. Selected patients underwent B-scan examination, magnetic resonance imaging of the brain, orbits and the optic nerves or visual evoked potential assessment. The injuries, investigations and procedures were entered into the patient's case sheet as well as into a standardised format suggested by the Indian eye injury registry (IER). Results 16 of 28 patients (57.1%) had ocular injuries whereas 12 (42.8%) were found to be normal. Injuries were seen unilaterally in 10 patients and bilaterally in six yielding a total of 22 injured eyes. The common injuries were periorbital haemorrhages (09 eyes, 40%); first or second degree burns to the upper or lower lids (seen in 07 eyes, 31.8 %) and corneal injuries (seen in 08 eyes, 36.3%). Open globe injuries were seen in two eyes of two patients (09%). One patient (4.5%) had a traumatic optic neuropathy. Conclusion Ophthalmologists and traumatologists should be aware of these patterns of ocular injuries. Protocols need to include the screening of large numbers of patients in a short time, diagnostic tests (B scan, visual evoked potential (VEP) etc) and early surgery preferably at
Relativistic nuclear Hamiltonian and currents to (v/c){sub 2}.
R. Schiavilla
1995-08-01
Relativistic Hamiltonians are defines as the sum of relativistic one-body kinetic energies and many-body interactions and their boost corrections. The calculation of the latter from commutation relations of the Poincare group is reviewed. It is shown that the most important terms can be understood from classical relativistic mechanics. The constraints of relativistic covariance on the charge and current densities are examined. Nuclear charge and current operators that satisfy them up to order (1/m){sup 2} are derived.
Lan, Tran Thi Ngoc; Liem, Ngo Quang; Binh, Nguyen Thi Thanh
2013-04-01
Personal exposure to benzene of selected population groups, and impacts of traffic on commuters in Ho Chi Minh City were investigated. The study was carried out in June, July and November 2010. The preliminary data showed that on average, personal exposure to benzene for non-occupational people in Ho Chi Minh is ~18 μg/m(3) and most of the exposure is due to commuting. Benzene exposure during travelling by bus, taxi and motorcycle is, respectively, 22-30, 22-39 and 185-240 μg/m(3). Motorcycle-taxi drivers, petrol filling employees and street vendors suffer high daily exposures at 116, 52, 32 μg/m(3), respectively. Further measurements are needed for a better risk assessment and finding effective measures to reduce exposure. PMID:23334286