9,733 research outputs found
B -> pi l nu at three lattice spacings
The increasing accuracy of experimental results for the exclusive,
semileptonic decay B -> pi l nu requires a similarly accurate calculation of
the hadronic matrix elements, to determine |Vub|. We present preliminary
results for the form factors of the B to light meson decay mode. Using results
from three lattices in the range 5.7 <= beta <= 6.1 we study the dependence on
the lattice spacing.Comment: LATTICE98(heavyqk), LaTeX, 3 pages, 4 postscript figures, uses
espcrc2.st
Estimated Errors in |Vcd|/|Vcs| from Semileptonic D Decays
We estimate statistical and systematic errors in the extraction of the CKM
ratio |Vcd|/|Vcs| from exclusive D-meson semileptonic decays using lattice QCD
and anticipated new experimental results.Comment: LATTICE98(heavyqk), LaTeX, 3 pages, 2 postscript figures, uses
espcrc2.sty and hyperbasics.te
Non-Perturbative Renormalization and the Fermilab Action
We discuss the application of the regularization independent (RI) scheme of
Rome/Southampton to determine the normalization of heavy quark operators
non-perturbatively using the Fermilab action.Comment: Lattice2003(improve), 3 pages, 2 figure
Heavy-light meson in anisotropic lattice QCD
We examine whether the improved quark action on anisotropic lattices
can be used as a framework for the heavy quark, which enables precision
computation of matrix elements of heavy-light mesons. To this end, it is
crucial to verify that a mass independent and nonperturbative tuning of the
parameters is possible. As a first step, we observe the dispersion relation of
heavy-light mesons on a quenched lattice using the action which is
nonperturbatively tuned only for the leading terms. On a lattice with the
spatial cutoff 1.6 GeV and the anisotropy , the
relativity relation holds within 2% accuracy in the quark mass region with the bare anisotropy parameter tuned for the massless quark.
We also apply the action to a calculation of heavy-light decay constants in the
charm quark mass region.Comment: Lattice2002(heavyquark), 3 pages, 2 figure
A perturbative determination of the parameters of an anisotropic quark action
The parameters of a 3+1 anisotropic quark action with Symanzik-improved glue
are determined at 1-loop in perturbation theory.Comment: 3 pages, 2 figures. Talk presented at Lattice2004(improved),
Fermilab, June 21-26, 200
Relay Communication with Real Time Microgrid Simulation
The development of smart grids with increasing penetration of renewable energy sources into the electrical grids have raised several technical challenges for the control and monitoring. One of these challenges is the system reliability, which depends on power gridsâ resilience and high integrity of data. The protective relays play vital role in the grid reliability that involves monitoring power lines and mitigating blackouts. In a large power grid, the protective relays operate locally by controlling the opening and closing of switches (breakers) in power lines, which allows to disconnect or remove from service any part of the power system when it operates in abnormal manner that might cause damage to the rest of the system. However, these relays are prone to failures, which lead random opening/closing of the breakers. Therefore, to back up the protection systems, it is necessary to study the relays failures and it effect on a large power grid. The focus of this research is the development of Hardware-in-the-Loop (HIL) Simulation that allows to safely emulate and study the power systems and relays under different operating condition. HIL is the standard industrial method for developing and testing the most complex control, protection and monitoring systems. In this HIL simulation, we use a real-time simulator as a virtual representation of a large power system connected to a real device that is a Schweitzer relay (SEL). A host computer is used to develop a simulation model of a power system and then runs in a target that is real-time target simulator that is an opal RT system. The HIL simulation contains software/hardware interface that enable to control the virtual input to the real system (SEL) and vice-versa
Autonomy support, basic need satisfaction and the optimal functioning of adult male and female sport participants: A test of basic needs theory
Grounded in Basic Needs Theory (BNT; Ryan and Deci, American Psychologist, 55, 68â78, 2000a), the present study aimed to: (a) test a theoretically-based model of coach autonomy support, motivational processes and well-/ill being among a sample of adult sport participants, (b) discern which basic psychological need(s) mediate the link between autonomy support and well-/ill-being, and (c) explore gender invariance in the hypothesized model. Five hundred and thirty nine participants (Male = 271;Female = 268; Mage = 22.75) completed a multi-section questionnaire tapping the targeted variables. Structural Equation Modeling (SEM) analysis revealed that coach autonomy support predicted participantsâ basic need satisfaction for autonomy, competence and relatedness. In turn, basic need satisfaction predicted greater subjective vitality when engaged in sport. Participants with low levels of autonomy were more susceptible to feeling emotionally and physically exhausted from their sport investment. Autonomy and competence partially mediated the path from autonomy support to subjective vitality. Lastly, the results supported partial invariance of the model with respect to gender
Interplay between perturbative and non-perturbative effects with the ARES method
We present a new semi-numerical method to compute leading hadronisation
corrections to two-jet event shapes in annihilation. The formalism we
present utilises the dispersive approach, where the magnitude of power
corrections is controlled by suitable moments of an effective strong coupling,
but it can be adapted to other methods. We focus on observables where the
interplay between perturbative and non-perturbative effects is crucial in
determining the power corrections. A naive treatment of power corrections for
some of these observables gives rise to an unphysical behaviour in the
corresponding distributions for moderate observable values, thus considerably
limiting the available range to fit the non-perturbative moments. We present a
universal treatment to handle such observables, based on a suitable subtraction
procedure, and compare our results to the analytic result in the case of total
broadening. Finally, for the first time we present predictions for the thrust
major, which cannot be handled with analytic methods.Comment: The revised version contains an additional figure and provides
further clarification
Evidence and rationale for expanding The Views of Nature of Science Questionnaire
In an attempt to understand nature of science (NOS) conceptions held by learners in greater detail, researchers have steadily become more reliant on open-ended measures. The Views of Science Questionnaire (VNOS) is the most frequently used open-ended instrument. Conceptually grounded in many of the same aspects emphasized in the Next Generation Science Standards, the VNOS-C is appropriate for capturing the views of secondary school students and adults along 10 dimensions related to NOS. However, it has been observed that the 10-item VNOS-C seems to have difficulty uncovering some particular NOS aspects, or rather respondents may need additional prompting. Two new items have been developed and administered to expand the VNOS instrument (VNOS-CE). The present study focuses on evaluating whether these items function as intended, soliciting responses for the target NOS aspects, and whether these contributions add value to the instrument as a whole. Data comes from 37 pre- and in-service elementary, middle and secondary teachers. Results suggest one of the items adds considerable breadth, eliciting responses from multiple NOS aspects, while the other adds much needed depth related to one aspect, social NOS. Implications for the field and assessment of NOS are discussed
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