162 research outputs found

    Design and User Satisfaction of Interactive Maps for Visually Impaired People

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    Multimodal interactive maps are a solution for presenting spatial information to visually impaired people. In this paper, we present an interactive multimodal map prototype that is based on a tactile paper map, a multi-touch screen and audio output. We first describe the different steps for designing an interactive map: drawing and printing the tactile paper map, choice of multi-touch technology, interaction technologies and the software architecture. Then we describe the method used to assess user satisfaction. We provide data showing that an interactive map - although based on a unique, elementary, double tap interaction - has been met with a high level of user satisfaction. Interestingly, satisfaction is independent of a user's age, previous visual experience or Braille experience. This prototype will be used as a platform to design advanced interactions for spatial learning

    Interactivity Improves Usability of Geographic Maps for Visually Impaired People

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    International audienceTactile relief maps are used by visually impaired people to acquire mental representation of space, but they retain important limitations (limited amount of information, braille text, etc.). Interactive maps may overcome these limitations. However, usability of these two types of maps had never been compared. It is then unknown whether interactive maps are equivalent or even better solutions than traditional raised-line maps. This study presents a comparison of usability of a classical raised-line map vs. an interactive map composed by a multi-touch screen, a raised-line overlay and audio output. Both maps were tested by 24 blind participants. We measured usability as efficiency, effectiveness and satisfaction. Our results show that replacing braille with simple audio-tactile interaction significantly improved efficiency and user satisfaction. Effectiveness was not related to the map type but depended on users' characteristics as well as the category of assessed spatial knowledge. Long-term evaluation of acquired spatial information revealed that maps, whether interactive or not, are useful to build robust survey-type mental representations in blind users. Altogether, these results are encouraging as they show that interactive maps are a good solution for improving map exploration and cognitive mapping in visually impaired people

    Study of e+e- --> pi+ pi- pi0 process using initial state radiation with BABAR

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    The process e+e- --> pi+ pi- pi0 gamma has been studied at a center-of-mass energy near the Y(4S) resonance using a 89.3 fb-1 data sample collected with the BaBar detector at the PEP-II collider. From the measured 3pi mass spectrum we have obtained the products of branching fractions for the omega and phi mesons, B(omega --> e+e-)B(omega --> 3pi)=(6.70 +/- 0.06 +/- 0.27)10-5 and B(phi --> e+e-)B(phi --> 3pi)=(4.30 +/- 0.08 +/- 0.21)10-5, and evaluated the e+e- --> pi+ pi- pi0 cross section for the e+e- center-of-mass energy range 1.05 to 3.00 GeV. About 900 e+e- --> J/psi gamma --> pi+ pi- pi0 gamma events have been selected and the branching fraction B(J/psi --> pi+ pi- pi0)=(2.18 +/- 0.19)% has been measured.Comment: 21 pages, 37 postscript figues, submitted to Phys. Rev.

    Measurement of Branching Fraction and Dalitz Distribution for B0->D(*)+/- K0 pi-/+ Decays

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    We present measurements of the branching fractions for the three-body decays B0 -> D(*)-/+ K0 pi^+/-andtheirresonantsubmodes and their resonant submodes B0 -> D(*)-/+ K*+/- using a sample of approximately 88 million BBbar pairs collected by the BABAR detector at the PEP-II asymmetric energy storage ring. We measure: B(B0->D-/+ K0 pi+/-)=(4.9 +/- 0.7(stat) +/- 0.5 (syst)) 10^{-4} B(B0->D*-/+ K0 pi+/-)=(3.0 +/- 0.7(stat) +/- 0.3 (syst)) 10^{-4} B(B0->D-/+ K*+/-)=(4.6 +/- 0.6(stat) +/- 0.5 (syst)) 10^{-4} B(B0->D*-/+ K*+/-)=(3.2 +/- 0.6(stat) +/- 0.3 (syst)) 10^{-4} From these measurements we determine the fractions of resonant events to be : f(B0-> D-/+ K*+/-) = 0.63 +/- 0.08(stat) +/- 0.04(syst) f(B0-> D*-/+ K*+/-) = 0.72 +/- 0.14(stat) +/- 0.05(syst)Comment: 7 pages, 3 figures submitted to Phys. Rev. Let

    Measurement of the B+ --> p pbar K+ Branching Fraction and Study of the Decay Dynamics

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    With a sample of 232x10^6 Upsilon(4S) --> BBbar events collected with the BaBar detector, we study the decay B+ --> p pbar K+ excluding charmonium decays to ppbar. We measure a branching fraction Br(B+ --> p pbar K+)=(6.7+/-0.5+/-0.4)x10^{-6}. An enhancement at low ppbar mass is observed and the Dalitz plot asymmetry suggests dominance of the penguin amplitude in this B decay. We search for a pentaquark candidate Theta*++ decaying into pK+ in the mass range 1.43 to 2.00 GeV/c2 and set limits on Br(B+ --> Theta*++pbar)xBr(Theta*++ --> pK+) at the 10^{-7} level.Comment: 8 pages, 7 postscript figures, submitted to Phys. Rev. D (Rapid Communications

    Search for the W-exchange decays B0 --> Ds(*)- Ds(*)+

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    We report a search for the decays B0DsDs+B^{0} \to D_{s}^{-} D_{s}^{+}, B0DsDs+B^{0} \to D_{s}^{*-} D_{s}^{+}, B0DsDs+B^{0} \to D_{s}^{*-} D_{s}^{*+} in a sample of 232 million Υ(4S)\Upsilon(4S) decays to \BBb ~pairs collected with the \babar detector at the PEP-II asymmetric-energy e+ee^+ e^- storage ring. We find no significant signal and set upper bounds for the branching fractions: B(B0DsDs+)<1.0×104,B(B0DsDs+)<1.3×104{\cal B}(B^{0} \to D_{s}^{-} D_{s}^{+}) < 1.0 \times 10^{-4}, {\cal B}(B^{0} \to D_{s}^{*-} D_{s}^{+}) < 1.3 \times 10^{-4} and B(B0DsDs+)<2.4×104{\cal B}(B^{0} \to D_{s}^{*-} D_{s}^{*+}) < 2.4 \times 10^{-4} at 90% confidence level.Comment: 8 pages, 2 figures, submitted to PRD-R

    Measurement of Branching Fractions for B0 ->K*2(1430)0 gamma and B+ -> K*2(1430)+ gamma

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    We have investigated the exclusive, radiative B-meson decay to K_2^*(1430) in 88.5 * 10^6 BBbar events. We present a preliminary measurement of the branching fractions BR(B->K^*_2(1430)^0 gamma) = (1.22+-0.25+-0.11) * 10^{-5} and BR(B->K^*_2(1430)^+ gamma) = (1.44+-0.40+-0.13) * 10^{-5}.Comment: 17 pages, 7 postscript figures, contributed to the 21st International Symposium on Lepton and Photon Interactions at High Energies, 8/11-8/16/2003, Fermilab, Illinois US

    Measurement of the Branching Fractions for Inclusive BB^- and Bˉ0\bar B^0 Decays to Flavor-tagged DD, DsD_s and Λc\Lambda_c

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    We report on the inclusive branching fractions of BB^- and of Bˉ0{\bar B}^0 mesons decaying to D0X{D^0 X}, Dˉ0X{{\bar D}^0 X}, D+X{D^+ X}, DX{D^- X}, Ds+X{D_s^+ X}, DsX{D_s^- X}, Λc+X{\Lambda_c^+ X}, ΛˉcX{{\bar \Lambda}_c^- X}, based on a sample of 88.9 million BBˉB \bar B events recorded with the BABARBABAR detector at the Υ(4S)\Upsilon(4S) resonance. Events are selected by completely reconstructing one BB and searching for a reconstructed charmed particle in the rest of the event. We measure the number of charmed and of anti-charmed particles per BB decay and derive the total charm yield per BB^- decay, nc=1.313±0.037±0.0620.042+0.063n_c^- = 1.313 \pm 0.037 \pm 0.062 ^{+0.063}_{-0.042} , and per Bˉ0{\bar B}^0 decay, nc0=1.276±0.062±0.0580.046+0.066n_c^0 = 1.276 \pm 0.062 \pm 0.058 ^{+0.066}_{-0.046} where the first uncertainty is statistical, the second is systematic, and the third reflects the charm branching-fraction uncertainties.Comment: 8 pages, 6 Encapsulated PostScript figures submitted to Phys. Rev. D (Rapid Communications

    Search for D0-D0bar Mixing Using Semileptonic Decay Modes

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    Based on an 87-fb1^{-1} dataset collected by the Babar detector at the PEP-II asymmetric-energy BB-Factory, a search for D0D^{0}--Dˉ0\bar{D}^{0} mixing has been made using the semileptonic decay modes D+π+D0,D0K()eνD^{*+} \to \pi^{+} D^{0}, D^{0} \to K^{(*)}e\nu (+c.c.). The use of these modes allows unambiguous flavor tagging and a combined fit of the D0D^{0} decay time and D+D^{*+}--D0D^{0} mass difference (ΔM\Delta M) distributions. The high-statistics sample of unmixed semileptonic D0D^{0} decays is used to model the ΔM\Delta M distribution and time-dependence of mixed events directly from the data. Neural networks are used to select events and reconstruct the D0D^{0}. A result consistent with no charm mixing has been obtained, Rmix=0.0023±0.0012±0.0004R_{\rm{mix}}=0.0023 \pm 0.0012 \pm 0.0004. This corresponds to an upper limit of Rmix<0.0042R_{\rm{mix}}<0.0042 (90% CL).Comment: submitted to Phys. Rev. D (Rapid Communications
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