6,306 research outputs found

    Tele-operated high speed anthropomorphic dextrous hands with object shape and texture identification

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    This paper reports on the development of two number of robotic hands have been developed which focus on tele-operated high speed anthropomorphic dextrous robotic hands. The aim of developing these hands was to achieve a system that seamlessly interfaced between humans and robots. To provide sensory feedback, to a remote operator tactile sensors were developed to be mounted on the robotic hands. Two systems were developed, the first, being a skin sensor capable of shape reconstruction placed on the palm of the hand to feed back the shape of objects grasped and the second is a highly sensitive tactile array for surface texture identification

    Hadronic B Decays to Charmed Baryons

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    We study exclusive B decays to final states containing a charmed baryon within the pole model framework. Since the strong coupling for ΛbBˉN\Lambda_b\bar B N is larger than that for ÎŁbBˉN\Sigma_b \bar BN, the two-body charmful decay B−→Σc0pˉB^-\to\Sigma_c^0\bar p has a rate larger than Bˉ0→Λc+pˉ\bar B^0\to\Lambda_c^+\bar p as the former proceeds via the Λb\Lambda_b pole while the latter via the ÎŁb\Sigma_b pole. By the same token, the three-body decay Bˉ0→Σc++pˉπ−\bar B^0\to\Sigma_c^{++}\bar p\pi^- receives less baryon-pole contribution than B−→Λc+pˉπ−B^-\to\Lambda_c^+\bar p\pi^-. However, because the important charmed-meson pole diagrams contribute constructively to the former and destructively to the latter, ÎŁc++pˉπ−\Sigma_c^{++}\bar p\pi^- has a rate slightly larger than Λc+pˉπ−\Lambda_c^+\bar p\pi^-. It is found that one quarter of the B−→Λc+pˉπ−B^-\to \Lambda_c^+\bar p\pi^- rate comes from the resonant contributions. We discuss the decays Bˉ0→Σc0pˉπ+\bar B^0\to\Sigma_c^0\bar p\pi^+ and B−→Σc0pˉπ0B^-\to\Sigma_c^0\bar p\pi^0 and stress that they are not color suppressed even though they can only proceed via an internal W emission.Comment: 25 pages, 6 figure

    American Library Association (ALA) Midwinter Meeting Report

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    The American Library Association Midwinter Meeting was held in San Antonio, Texas, January 20–25, 2006. The following are highlights from the meeting. We have a range of coverage and reviewers. Christopher Cox gives us an update on groups discussing digital media such as HD-DVD and Blu-ray, electronic reference books, and RFID issues. Hui Hua Chua writes about a discussion on federated searching. M. Claire Stewart reports on the inaugural meeting of the ALCTS Preservation and Reformatting Section’s Digital Preservation Discussion Group and a whirlwind meeting on standards, which included the discussion of five standards and the overall National Information Standards Organization (NISO) structure. We conclude with a review of the day-long program on OCLC Digitization Standards sponsored by OCLC Digital Collection Services & Preservation Service Center by S.G. Ranti Junus

    Bˉ0→π+X\bar B^0 \to \pi^+ X in the Standard Model

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    In this paper we investigate the possibility of studying B→πB\to \pi form factor using the semi-inclusive decays Bˉ0→π++Xq\bar B^0 \to \pi^+ + X_q. In general B→PXB\to PX semi-inclusive decays involve several hadronic parameters. But for Bˉ0→π+Xq\bar B^0 \to \pi^+ X_q decays we find that in the factorization approximation, the only unknown hadronic parameters are the form factors F0,1B→πF^{B\to \pi}_{0,1}. Therefore these form factors can be studied in Bˉ0→π+Xq\bar B^0 \to \pi^+ X_q decays. Using theoretical model calculations for the form factors the branching ratios for Bˉ0→π+Xd(ΔS=0)\bar B^0 \to \pi^+ X_d(\Delta S = 0) and Bˉ0→π+Xs(ΔS=−1)\bar B^0 \to \pi^+ X_s (\Delta S = -1), with the cut Eπ>2.1E_{\pi} > 2.1 GeV, are estimated to be in the ranges of (3.1∌4.9)×10−5(F1B→π(0)/0.33)2(3.1\sim 4.9) \times 10^{-5}(F^{B\to \pi}_1(0)/0.33)^2 and (2.5∌4.2)×10−5(F1B→π(0)/0.33)2(2.5\sim 4.2)\times 10^{-5}(F_1^{B\to \pi}(0)/0.33)^2, respectively, depending on the value of Îł\gamma. The combined branching ratio for Bˉ0→π+(Xd+Xs)\bar B^0 \to \pi^+ (X_d+ X_s) is about 7.4×10−5(F1B→π(0)/0.33)27.4\times 10^{-5} (F^{B\to \pi}_1(0)/0.33)^2 and is insensitive to Îł\gamma. We also discuss CP asymmetries in these decay modes.Comment: RevTex 8 pages and two figure

    Charmless Three-Body Baryonic B Decays

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    Motivated by recent data on B-> p pbar K decay, we study various charmless three-body baryonic B decay modes, including Lambda pbar pi, Sigma0 pbar pi, p pbar pi, p pbar Kbar0, in a factorization approach. These modes have rates of order 10^{-6}. There are two mechanisms for the baryon pair production, current-produced and transition. The behavior of decay spectra from these baryon production mechanisms can be understood by using QCD counting rules. Predictions on rates and decay spectra can be checked in the near future.Comment: 26 pages, 9 figures; version to appear in Phys. Rev.

    Phenomenological Consequences of Right-handed Down Squark Mixings

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    The mixings of dRd_R quarks, hidden from view in Standard Model (SM), are naturally the largest if one has an Abelian flavor symmetry. With supersymmetry (SUSY) their effects can surface via d~R\tilde d_R squark loops. Squark and gluino masses are at TeV scale, but they can still induce effects comparable to SM in BdB_d (or BsB_s) mixings, while D0D^0 mixing could be close to recent hints from data. In general, CP phases would be different from SM, as may be indicated by recent B Factory data. Presence of non-standard soft SUSY breakings with large tan⁥ÎČ\tan\beta could enhance b→dÎłb\to d\gamma (or sÎłs\gamma) transitions.Comment: Version to appear in Phys. Rev. Let

    The Fourth Element: Characteristics, Modelling, and Electromagnetic Theory of the Memristor

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    In 2008, researchers at HP Labs published a paper in {\it Nature} reporting the realisation of a new basic circuit element that completes the missing link between charge and flux-linkage, which was postulated by Leon Chua in 1971. The HP memristor is based on a nanometer scale TiO2_2 thin-film, containing a doped region and an undoped region. Further to proposed applications of memristors in artificial biological systems and nonvolatile RAM (NVRAM), they also enable reconfigurable nanoelectronics. Moreover, memristors provide new paradigms in application specific integrated circuits (ASICs) and field programmable gate arrays (FPGAs). A significant reduction in area with an unprecedented memory capacity and device density are the potential advantages of memristors for Integrated Circuits (ICs). This work reviews the memristor and provides mathematical and SPICE models for memristors. Insight into the memristor device is given via recalling the quasi-static expansion of Maxwell's equations. We also review Chua's arguments based on electromagnetic theory.Comment: 28 pages, 14 figures, Accepted as a regular paper - the Proceedings of Royal Society

    Quantum Hall Effect and Quantum Point Contact in Bilayer-Patched Epitaxial Graphene

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    We study an epitaxial graphene monolayer with bilayer inclusions via magnetotransport measurements and scanning gate microscopy at low temperatures. We find that bilayer inclusions can be metallic or insulating depending on the initial and gated carrier density. The metallic bilayers act as equipotential shorts for edge currents, while closely spaced insulating bilayers guide the flow of electrons in the monolayer constriction, which was locally gated using a scanning gate probe.Comment: 5 pages, 5 figure

    SU(3) and Nonet Breaking Effects in KL→γγK_L \to \gamma \gamma Induced by s→d+2gluons \to d + 2{gluon} due to Anomaly

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    In this paper we study the effects of s→d+2gluons\to d + 2{gluon} on KL→γγK_L \to \gamma\gamma in the Standard Model. We find that this interaction can induce new sizeable SU(3) and U(3) nonet breaking effects in KL−η,ηâ€ČK_L - \eta, \eta' transitions and therefore in KL→γγK_L\to \gamma\gamma due to large matrix elements of from QCD anomaly. These new effects play an important role in explaining the observed value. We also study the effects of this interaction on the contribution to ΔmKL−KS\Delta m_{K_L-K_S}.Comment: RevTex, 12 Pages, no figures. Version to be published in PR

    Accounting for Slow J/psi from B Decay

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    A slow J/psi excess exists in the inclusive B -> J/psi+X spectrum, and is indicative of some hadronic effect. From color octet nature of c cbar pair in b-> c cbar s decay, one such possibility would be B -> J/psi+ K_g decay, where K_g is a hybrid resonance with sbar g q constituents. We show that a K_g resonance of ~ 2 GeV mass and suitably broad width could be behind the excess.Comment: 4 pages, 2 figures. To appear in Phys. Rev.
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