415 research outputs found

    Anthropomorphic user interface feedback in a sewing context and affordances

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    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

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    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

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    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 KNKN 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

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    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 (ΞΞ\Xi\Xi and NNNN), and three and four baryons (3He^3{\rm He} and 4He)^4{\rm He}) as well, employing (2+1)-flavor lattice QCD at mπ=0.51m_{\pi}=0.51 GeV on four lattice volumes with L=L= 2.9, 3.6, 4.3 and 5.8 fm. Caution is given for drawing conclusion on the bound NNNN, 3N3N and 4N4N 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--

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    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

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    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

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    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 mπ500m_\pi\sim 500 MeV and that of PACS-CS collaboration for much lighter quark masses down to mπ=155m_\pi=155 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

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    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 32432^4 lattice with the lattice spacing a0.137a \simeq 0.137 fm (lattice volume (4.4 fm)4^4) 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

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    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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