597 research outputs found

    Interaction With Tilting Gestures In Ubiquitous Environments

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    In this paper, we introduce a tilting interface that controls direction based applications in ubiquitous environments. A tilt interface is useful for situations that require remote and quick interactions or that are executed in public spaces. We explored the proposed tilting interface with different application types and classified the tilting interaction techniques. Augmenting objects with sensors can potentially address the problem of the lack of intuitive and natural input devices in ubiquitous environments. We have conducted an experiment to test the usability of the proposed tilting interface to compare it with conventional input devices and hand gestures. The experiment results showed greater improvement of the tilt gestures in comparison with hand gestures in terms of speed, accuracy, and user satisfaction.Comment: 13 pages, 10 figure

    Transverse double-spin asymmetries for small QTQ_T Drell-Yan pair production in pppp and ppˉp\bar{p} collisions

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    We discuss transverse double-spin asymmetries for dimuon production at small transverse-momentum QTQ_T in pppp and ppˉp\bar{p} collisions. All order resummation of large logarithms relevant in small QTQ_T region is performed at next-to-leading logarithmic (NLL) accuracy, and asymmetries at RHIC, J-PARC and GSI are calculated.Comment: 4 pages, 2 figures, Talk given at DIS06, April 20-24, 2006, Tsukuba, Japa

    Unravelling soft components in the shape function for inclusive B decays

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    In the heavy-quark limit, the decay spectrum for radiative and semileptonic inclusive B-meson decays is determined by a universal structure function, i.e. the shape function. We study the constraints on the bilocal heavy-quark operator for the shape function from the QCD equations of motion and heavy-quark symmetry, and we obtain a new basis of nonlocal operators that reveals relevant soft components in the shape function. Those nonlocal operators represent the ``kinetic energy distribution'' of the b-quark inside the B-meson and the four-parton correlations with additional quarks and gluons. A corresponding local operator basis relevant for relating the shape function to HQET parameters is also given, and novel effects of the quark-gluon correlations are discussed.Comment: 19 pages PTPTeX. Typos corrected and improvements made to the text. References added. Published versio

    Social Integration of the San Society From the Viewpoint of Sexual Relationships (Natural History of Communication among the Central Kalahari San)

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    The Central Kalahari San, living in the central part of Botswana, practice divorce and remarriage frequently. Most people have experienced marriage more than twice in their lives. The rate of polygamous marriage is rather high, and moreover, a kind of love-relationship called zÄ ku, which is usually recognized openly, is widely seen in this society. Four examples of social clusters united by marriage and other sexual relationships are here examined and analyzed to see how those sexual relationships affect inter-personal relations and residential grouping. This is done in order to clarify an aspect of the principle of San social integration

    B meson light-cone distribution amplitudes in the heavy-quark limit

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    We investigate the B meson light-cone distribution amplitudes in the heavy-quark limit which are relevant for the QCD factorization approach for the exclusive B meson decays. We derive exact relations between two- and three-particle distribution amplitudes from the QCD equations of motion and heavy-quark symmetry constraint. As solution of these relations, we give representations for the quark-antiquark distribution amplitudes in terms of independent dynamical degrees of freedom. In particular, we find that the Wandzura-Wilczek-type contributions are determined uniquely in analytic form in terms of \bar{\Lambda}, a fundamental mass parameter of heavy-quark effective theory, and that both leading- and higher-twist distribution amplitudes receive the contributions of multi-particle states with additional gluons.Comment: 11 pages LaTeX; error in eqs. (6) and (11) corrected, and minor change

    Pressure effects on fluorescence and photodimerization of anthracene and 9-methylanthracene in solution

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    The relative values of photodimerization yields Φ. and fluorescence yields Φ_f with anthracene and 9-methylanthracene were measured in n-hexane at room temperature under pressures up to 3, 000kg/cm^2. In anthracene where Φ_f has a slight pressure dependence, the apparent first order rate constant k_o_b_s for photodimerization yield was approximately inversely proportinal to the viscosity of the solvent. On the other hand, in 9-methylanthrareae where Φ_f increases steeply with increasing pressure, k_o_b_s did not decrease with pressure so much as predicted from the increase of the viscosity of the solvent. Considering the changes of Φ_f as the changes of lifetime. τ_f of the lowest excited singlet state S_1, the pressure dependences of photodimerization rate constants k_r were obtained according to the relation k_o_b_s = k_r.τ_f. In 9-methylanthracene as well as anthracene k_r were nearly inversely proportional to the viscosity of the solvent. The remarkable effects of pressure on fluorescence yields also were discussed in view of the intersystem crossing from the S_1 state to the second triplet state T_2

    Transverse Momentum Distribution in the B Mesons in the Heavy-quark Limit: the Wandzura-Wilczek Part

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    In the heavy-quark limit, the valence Fock-state components in the B mesons are described by a set of two light-cone wavefunctions. We show that these two wavefunctions obey simple coupled differential equations, which are based on the equations of motion in the Heavy Quark Effective Theory (HQET), and the analytic solutions for them are obtained. The results generalize the recently obtained longitudinal-momentum distribution in the Wandzura-Wilczek approximation by including the transverse momenta. We find that the transverse momentum distribution depends on the longitudinal momentum of the constituents, and that the wavefunctions damp very slowly for large transverse separation between quark and antiquark.Comment: 7 pages LaTeX. Discussion about the difference between the Wandzura-Wilczek approximation and the full result for the first moment is added in the final part. Minor corrections in the other part. Some footnotes and Refs are adde

    MobileCA: Accumulative Secure Group Association with a Certification Path

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    AbstractIn recent years, there has been growing interest in secure pairing, which refers to the establishment of a secure connection between two mobile devices. Many published studies have described the various types of out-of-band (OOB) channels through which authentication data can be transferred with user control and involvement. However, there has been little discussion of setting up secure connections between groups of mobile devices. Some security protocols have been proposed, but they have tended to focus on a scenario whereby all devices must be located in one place to perform the association.In this paper, we describe a new group association method, called MobileCA. Our method is designed for a broader range of scenarios and does not require all devices to be in one place at one time. MobileCA extends the OOB channel concept and utilizes digital certification. We have implemented a prototype system using smart phone handsets
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