415 research outputs found
Anthropomorphic user interface feedback in a sewing context and affordances
The aim of the authors' research is to gain better insights into the effectiveness and user satisfaction of anthropomorphism at the user interface. Therefore, this paper presents a between users experiment and the results in the context of anthropomorphism at the user interface and the giving of instruction for learning sewing stitches. Two experimental conditions were used, where the information for learning sewing stitches was the same. However the manner of presentation was varied. Therefore one condition was anthropomorphic and the other was non-anthropomorphic. Also the work is closely linked with Hartson's theory of affordances applied to user interfaces. The results suggest that facilitation of the affordances in an anthropomorphic user interface lead to statistically significant results in terms of effectiveness and user satisfaction in the sewing context. Further some violation of the affordances leads to an interface being less usable in terms of effectiveness and user satisfaction
Spin-Orbit Force from Lattice QCD
We present a first attempt to determine nucleon-nucleon potentials in the
parity-odd sector, which appear in 1P1, 3P0, 3P1, 3P2-3F2 channels, in Nf=2
lattice QCD simulations. These potentials are constructed from the
Nambu-Bethe-Salpeter wave functions for J^P=0^-, 1^- and 2^-, which correspond
to A1^-, T1^- and T2^- + E^- representation of the cubic group, respectively.
We have found a large and attractive spin-orbit potential VLS(r) in the
isospin-triplet channel, which is qualitatively consistent with the
phenomenological determination from the experimental scattering phase shifts.
The potentials obtained from lattice QCD are used to calculate the scattering
phase shifts in 1P1, 3P0, 3P1 and 3P2-3F2 channels. The strong attractive
spin-orbit force and a weak repulsive central force in spin-triplet P-wave
channels lead to an attraction in the 3P2 channel, which is related to the
P-wave neutron paring in neutron stars.Comment: 14 pages, 5 figures, Physics Letters B published versio
Kaon-Nucleon potential from lattice QCD
We study the KN interactions in the I(J^{\pi})=0(1/2^-) and 1(1/2^-) channels
and associated exotic state \Theta^+ from 2+1 flavor full lattice QCD
simulation for relatively heavy quark mass corresponding to m_{\pi}=871 MeV.
The s-wave KN potentials are obtained from the Bethe-Salpeter wave function by
using the method recently developed by HAL QCD (Hadrons to Atomic nuclei from
Lattice QCD) Collaboration. Potentials in both channels reveal short range
repulsions: Strength of the repulsion is stronger in the I=1 potential, which
is consistent with the prediction of the Tomozawa-Weinberg term. The I=0
potential is found to have attractive well at mid range. From these potentials,
the scattering phase shifts are calculated and compared with the
experimental data.Comment: Talk given at 19th International IUPAP Conference on Few-Body
Problems in Physics (fb19), Bonn, Germany, 30 Aug - 5 Sep 200
Mirage in Temporal Correlation functions for Baryon-Baryon Interactions in Lattice QCD
Single state saturation of the temporal correlation function is a key
condition to extract physical observables such as energies and matrix elements
of hadrons from lattice QCD simulations. A method commonly employed to check
the saturation is to seek for a plateau of the observables for large Euclidean
time. Identifying the plateau in the cases having nearby states, however, is
non-trivial and one may even be misled by a fake plateau. Such a situation
takes place typically for the system with two or more baryons. In this study,
we demonstrate explicitly the danger from a possible fake plateau in the
temporal correlation functions mainly for two baryons ( and ), and
three and four baryons ( and as well, employing
(2+1)-flavor lattice QCD at GeV on four lattice volumes with
2.9, 3.6, 4.3 and 5.8 fm. Caution is given for drawing conclusion on the
bound , and systems only based on the temporal correlation
functions.Comment: 32 pages, 13 figures, minor corrections, published version, typos
correcte
Nucleon-nucleon interactions via Lattice QCD: Methodology --HAL QCD approach to extract hadronic interactions in lattice QCD--
We review the potential method in lattice QCD, which has recently been
proposed to extract nucleon-nucleon interactions via numerical simulations. We
focus on the methodology of this approach by emphasizing the strategy of the
potential method, the theoretical foundation behind it, and special numerical
techniques. We compare the potential method with the standard finite volume
method in lattice QCD, in order to make pros and cons of the approach clear. We
also present several numerical results for the nucleon-nucleon potentials.Comment: 12 pages, 10 figure
Predictive model for scanned probe oxidation kinetics
Previous descriptions of scanned probe oxidation kinetics involved implicit assumptions that one-dimensional, steady-state models apply for arbitrary values of applied voltage and pulse duration. These assumptions have led to inconsistent interpretations regarding the fundamental processes that contribute to control of oxide growth rate. We propose a model that includes a temporal crossover of the system from transient to steady-state growth and a spatial crossover from predominantly vertical to coupled lateral growth. The model provides an excellent fit of available experimental data
Non-perturbative renormalization of quark mass in Nf=2+1 QCD with the Schroedinger functional scheme
We present an evaluation of the quark mass renormalization factor for Nf=2+1
QCD. The Schroedinger functional scheme is employed as the intermediate scheme
to carry out non-perturbative running from the low energy region, where
renormalization of bare mass is performed on the lattice, to deep in the high
energy perturbative region, where the conversion to the renormalization group
invariant mass or the MS-bar scheme is safely carried out. For numerical
simulations we adopted the Iwasaki gauge action and non-perturbatively improved
Wilson fermion action with the clover term. Seven renormalization scales are
used to cover from low to high energy regions and three lattice spacings to
take the continuum limit at each scale. The regularization independent step
scaling function of the quark mass for the Nf=2+1 QCD is obtained in the
continuum limit. Renormalization factors for the pseudo scalar density and the
axial vector current are also evaluated for the same action and the bare
couplings as two recent large scale Nf=2+1 simulations; previous work of the
CP-PACS/JLQCD collaboration, which covered the up-down quark mass range heavier
than MeV and that of PACS-CS collaboration for much lighter
quark masses down to MeV. The quark mass renormalization factor is
used to renormalize bare PCAC masses in these simulations.Comment: 26 pages, 17 Postscript figures. Two tables are update
Nuclear Force from Monte Carlo Simulations of Lattice Quantum Chromodynamics
The nuclear force acting between protons and neutrons is studied in the Monte
Carlo simulations of the fundamental theory of the strong interaction, the
quantum chromodynamics defined on the hypercubic space-time lattice. After a
brief summary of the empirical nucleon-nucleon (NN) potentials which can fit
the NN scattering experiments in high precision, we outline the basic
formulation to derive the potential between the extended objects such as the
nucleons composed of quarks. The equal-time Bethe-Salpeter amplitude is a key
ingredient for defining the NN potential on the lattice. We show the results of
the numerical simulations on a lattice with the lattice spacing fm (lattice volume (4.4 fm)) in the quenched approximation.
The calculation was carried out using the massively parallel computer Blue
Gene/L at KEK. We found that the calculated NN potential at low energy has
basic features expected from the empirical NN potentials; attraction at long
and medium distances and the repulsive core at short distance. Various future
directions along this line of research are also summarized.Comment: 13 pages, 4 figures, version accepted for publication in
"Computational Science & Discovery" (IOP
Heteromysis cocoensis n. sp. (Crustacea: Mysida: Mysidae) from coastal waters of Isla del Coco, Costa Rica
A survey of the invertebrate fauna of coral reef hard bottom communities in the shallow waters of Isla del Coco yielded a new species of mysid belonging to the genus Heteromysis S. I. Smith, 1873. Heteromysis (Olivemysis) cocoensis, n. sp. was collected from coral rubble at depths of 8 to 34 m. It differs from its congeners by having male pleopods 1, 3, and 4 with modified setae. Within the subgenus Olivemysis Băcescu, 1968, the new species is morphologically most similar to Heteromysis. ekamako Wittmann and Chevaldonne, 2017 from the Pacific, Heteromysis. gomezi Băcescu, 1970, H. mayana Brattegard, 1970, and H. rubrocinta, Băcescu, 1968 from the Western Atlantic, and Heteromysis. dardani Wittmann, 2008, Heteromysis. wirtzi Wittmann, 2008, and Heteromysis. sabelliphila Wittmann and Wirtz, 2017 from the Eastern Atlantic. However, H. cocoensis n. sp. is distinguished from these six apparently closely related species by the following combination of characters: flagellate, modified setae on articles 1 and 3 of the antennular peduncle, and setation of thoracic endopod 3, male pleopods 1, 3 and 4, uropodal endopods, and the apical and lateral margins of the telson. A diagnostic table separating these eight species is given.Universidad de Costa Rica/[]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí
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