385 research outputs found

    Gyrotropic impact upon negatively refracting surfaces

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    Surface wave propagation at the interface between different types of gyrotropic materials and an isotropic negatively refracting medium, in which the relative permittivity and relative permeability are, simultaneously, negative is investigated. A general approach is taken that embraces both gyroelectric and gyromagnetic materials, permitting the possibility of operating in either the low GHz, THz or the optical frequency regimes. The classical transverse Voigt configuration is adopted and a complete analysis of non-reciprocal surface wave dispersion is presented. The impact of the surface polariton modes upon the reflection of both plane waves and beams is discussed in terms of resonances and an example of the influence upon the Goos–Hänchen shift is given

    Higgs-Boson Decay to Four Fermions Including a Single Top Quark Below ttˉt \bar t Threshold

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    The rare decay modes Higgs \rightarrow four light fermions, and Higgs \rightarrow single top-quark + three light fermions for mt<MH<2mtm_t<M_H<2m_t, are presented, and phenomenologically interpreted. The angular correlation between fermion planes is presented as a test of the spin and intrinsic parity of the Higgs particle. In Higgs decay to single top, two tree-level graphs contribute in the standard model (SM); one couples the Higgs to W+W(gMW)W^+W^-(\sim gM_W), and one to t\bar t(\sim g_{top\;yukawa}=m_t/246\GeV). The large Yukawa coupling for m_t>100\GeV makes the second amplitude competitive or dominant for most MH,mtM_H,m_t values. Thus the Higgs decay rate to single top directly probes the SM universal mechanism generating both gauge boson and fermion masses, and offers a means to infer the Higgs-ttˉt \bar t Yukawa coupling when HttˉH\rightarrow t \bar t is kinematically disallowed. We find that the modes ppXttˉ(HtbˉW())pp\rightarrow Xt\bar t(H\rightarrow t\bar b W^{(*)}) at the SSC, and e+eZorννˉ+(HtbˉW())e^+ e^-\rightarrow Z\,or\,\nu\bar{\nu} + (H\rightarrow t\bar b W^{(*)}) at future high energy, high luminosity colliders, may be measureable if 2mt2m_t is not too far above MHM_H. We classify non-standard Higgses as gaugeo-phobic, fermio-phobic or fermio-philic, and discuss the Higgs\rightarrow single top rates for these classes.Comment: 30 pages, 6 figures (figures available upon request); VAND-TH-93/

    The assessment of information technology maturity in emergency response organizations

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    [EN] In emergency response organizations, information technologies are not adequately explored. Sometimes, the mere adoption of new information technologies is not productive, as their efficient use depends on other interrelated technologies and the environment where they are installed. This work describes a model to help organizations understand their capability in respect to the adoption of these technologies. The model also helps the performing of the evaluation from different perspectives, making it suitable to collaborative evaluation. Using the proposed model, an organization can measure its maturity level in different aspects of the evaluation and guide the investment on its capabilities. Part of the model has been developed for emergency response organizations and the information technology dimension of the model has been applied to two fire department installations.Marcos R. S. Borges was partially supported by grants No. 560223/2010-2 and 480461/2009-0 from CNPq (Brazil). Work of José H. Canós is partially funded by the Spanish Ministerio. de Educación y Ciencia (MEC) under grant TIPEX (TIN2010–19859-C03-03). The cooperation between the Brazilian and the Spanish research groups was partially sponsored by the CAPES/MECD Cooperation Program, Project #169/ PHB2007-0064-PC.Santos, RS.; Borges, MRS.; Canos Cerda, JH.; Gomes, JO. (2011). The assessment of information technology maturity in emergency response organizations. Group Decision and Negotiation. 20(5):593-613. doi:10.1007/s10726-011-9232-zS593613205Bigley G, Roberts KH (2001) The incident command system: high reliability organizing for complex and volatile task environments. Acad Manag J 44(6): 1281–1299Chinowsky P, Molenaar K, Realph A (2007) Learning organizations in construction. J Manag Eng 23(1): 27–34Diniz VB, Borges MRS, Gomes JO, Canós JH (2008) Decision making support in emergency response. In: Encyclopedia of decision making, Information Science Reference (an imprint of IGI Global), New York, pp 184–191Dörner R, Grimm P, Seiler C (2001) ETOILE—an environment for team, organizational and individual learning. CG Top 13(3): 5–6Dykstra E (2003) Concept paper: toward an international system model in emergency management. In: Proceedings of toward an international system model in emergency management, Public Entity Risk InstituteFederal Emergency Management Agency (FEMA) (1998) Emergency management guide for business and industry: a step-by-step approach to emergency planning, response and recovery for companies of all sizesGu Q, Mendonça D (2005) Patterns of group information seeking in a simulated emergency response environment. In: Proceedings of the 2nd international ISCRAM conference, Brussels, BelgiumHale J (1997) A layered communication architecture for the support of crisis response. J Manag Inf Syst 14(1): 235–255King W, Teo T (1997) Integration between business planning and information systems planning: validating a stage hypothesis. Decis Sci 28(2): 279–307Lachner J, Hellwagner H (2008) Information and communication systems for mobile emergency response. Lecture notes in business information processing, vol 5. pp 213–224Lavoie D, Culbert A (1978) Stages in organization and development. Human Relat 31(5): 417–438Lindel MK, Prater C, Perry RW (2007) Emergency management. Wiley, New YorkLlavador M, Letelier P, Penadés MC, Borges MRS, Solís C (2006) Precise yet flexible specification of emergency resolution procedures. In: Proceedings of the information systems for crisis response and management (ISCRAM), pp 110–120Meissner A, Wang Z, Putz W, Grimmer J (2006) MIKoBOS: a mobile information and communication system for emergency response. In: Proceedings of the 3rd international ISCRAM conference, Newark, New JerseyNonaka I, Takeuchi H (1995) The knowledge creating company: how Japanese companies create the dynamics of innovation. Oxford University Press, OxfordOchoa S, Neyem A, Pino JA, Borges MRS (2007) Supporting group decision making and coordination in urban disasters relief efforts. J Decis Syst 16(2): 143–172Paton D, Flin R (1999) Disaster stress: an emergency management perspective. Disaster Prev Manag 8(4): 261–267Paulk MC, Weber C, Curtis B, Chrissis M (1995) The capability maturity model: guidelines for improving the software process. Addison-Wesley, ReadingQuarantelli EL (1997) Problematical aspects of the information/communication revolution for disaster planning and research: ten non-technical issues and questions. Disaster Prev Manag 6(2): 94–106Santos RS, Borges MRS, Gomes JO, Canós JH (2008) Maturity levels of information technologies in emergency response organizations. In: Proceedings of the international workshop on groupware, Omaha, Nebraska, USA. Groupware: design, implementation and use. Lecture notes in computer science, vol 5411. Springer, Berlin, pp 135–150Schoenharl T, Szabo G, Madey G, Barabasi AL (2006) WIPER: a multi-agent system for emergency response. In: Proceedings of the 3rd international ISCRAM conference, Newark, New JerseyTuroff M (2002) Past and future emergency response information systems. Commun ACM 45(4): 29–33Turoff M, Chumer M, Hiltz R, Clasher R, Alles M, Vasarhelyi M, Kogan A (2004a) Assuring homeland security: continuous monitoring, control and assurance of emergency preparedness. J Inf Technol Theor Appl (JITTA) 6(3): 1–24Turoff M, Chumer M, Vande Walle B, Yao X (2004b) The design of a dynamic emergency response management information system (DERMIS). J Inf Technol Theor Appl (JITTA) 5(4): 1–35Van der Lee MDE, Van Vugt M (2004) IMI—An information system for effective multidisciplinary incident management. In: Proceedings of the 1st international ISCRAM conference, Brussels, BelgiumYuan Y, Deltor B (2005) Intelligent mobile crisis response systems. Commun ACM 28(2): 95–98Zimmerman R, Restrepo CE (2006) Information technology (IT) and critical infrastructure interdependencies for emergency response. In: Proceedings of the 3rd international ISCRAM conference, Newark, New Jerse

    The AMANDA Neutrino Telescope

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    With an effective telescope area of order 10410^4 m2^2 for TeV neutrinos, a threshold near \sim50 GeV and a pointing accuracy of 2.5 degrees per muon track, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe early results on the calibration of natural deep ice as a particle detector as well as on AMANDA's performance as a neutrino telescope.Comment: 12 pages, Latex2.09, uses espcrc2.sty and epsf.sty, 13 postscript files included. Talk presented at the 18th International Conference on Neutrino Physics and Astrophysics (Neutrino 98), Takayama, Japan, June 199

    The pp -> K^+Sigma^+n cross section from missing mass spectra

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    We utilize existing inclusive data on K^+ meson momentum spectra of the reaction pp -> K^+X at T_p = 2.3 - 2.85 GeV to deduce total cross sections for pp -> K^+\Sigma^+n. The method used to extract those cross sections is explained and discussed in detail. Our result for T_p = 2.85 GeV is consistent with the data point from a direct measurement at the same beam energy. The cross section obtained for T_p = 2.3 GeV is with 13.7\pm2.3 \mu b considerably smaller than the value found in a recent experiment by the COSY-11 Collaboration at a somewhat lower beam energy, indicating that the pp -> K^+\Sigma^+n reaction cross section could exhibit a rather unusual energy dependence.Comment: 12 pages, 8 figure

    Sensitivity of the IceCube Detector to Astrophysical Sources of High Energy Muon Neutrinos

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    We present the results of a Monte-Carlo study of the sensitivity of the planned IceCube detector to predicted fluxes of muon neutrinos at TeV to PeV energies. A complete simulation of the detector and data analysis is used to study the detector's capability to search for muon neutrinos from sources such as active galaxies and gamma-ray bursts. We study the effective area and the angular resolution of the detector as a function of muon energy and angle of incidence. We present detailed calculations of the sensitivity of the detector to both diffuse and pointlike neutrino emissions, including an assessment of the sensitivity to neutrinos detected in coincidence with gamma-ray burst observations. After three years of datataking, IceCube will have been able to detect a point source flux of E^2*dN/dE = 7*10^-9 cm^-2s^-1GeV at a 5-sigma significance, or, in the absence of a signal, place a 90% c.l. limit at a level E^2*dN/dE = 2*10^-9 cm^-2s^-1GeV. A diffuse E-2 flux would be detectable at a minimum strength of E^2*dN/dE = 1*10^-8 cm^-2s^-1sr^-1GeV. A gamma-ray burst model following the formulation of Waxman and Bahcall would result in a 5-sigma effect after the observation of 200 bursts in coincidence with satellite observations of the gamma-rays.Comment: 33 pages, 13 figures, 6 table

    AAV-mediated rescue of Eps8 expression in vivo restores hair-cell function in a mouse model of recessive deafness

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    The transduction of acoustic information by hair cells depends upon mechanosensitive stereociliary bundles that project from their apical surface. Mutations or absence of the stereociliary protein EPS8 cause deafness in humans and mice, respectively. Eps8 knockout mice (Eps8−/−) have hair cells with immature stereocilia and fail to become sensory receptors. Here, we show that exogenous delivery of Eps8 using Anc80L65 in P1–P2 Eps8−/− mice in vivo rescued the hair bundle structure of apical-coil hair cells. Rescued hair bundles correctly localize EPS8, WHIRLIN, MYO15, and BAIAP2L2, and generate normal mechanoelectrical transducer currents. Inner hair cells with normal-looking stereocilia re-expressed adult-like basolateral ion channels (BK and KCNQ4) and have normal exocytosis. The number of hair cells undergoing full recovery was not sufficient to rescue hearing in Eps8−/− mice. Adeno-associated virus (AAV)-transduction of P3 apical-coil and P1–P2 basal-coil hair cells does not rescue hair cells, nor does Anc80L65-Eps8 delivery in adult Eps8−/− mice. We propose that AAV-induced gene-base therapy is an efficient strategy to recover the complex hair-cell defects in Eps8−/− mice. However, this therapeutic approach may need to be performed in utero since, at postnatal ages, Eps8−/− hair cells appear to have matured or accumulated damage beyond the point of repair

    Analysis of data on low energy piN-->pipiN reaction. I. Total cross sections

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    This is the first of a series of papers on a consistent model independent analysis of the complete experimental information on the reaction πNππN\pi N \rightarrow \pi \pi N at pion momenta up to 500 MeV/c. The paper summarizes the theoretical approach and details of the computational procedure. The complete database on total cross sections in 5 ππN\pi \pi N channels is given together with a critical discussion of their model independent analysis.Comment: 45 page

    Development of competences while solving real industrial interdisciplinary problems: a successful cooperation with industry

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    The development of projects in industrial context constitutes an exceptional opportunity for engineering students to develop competences expected by the labour market. Therefore, the adoption of this type of interaction within engineering curricula is highly recommended, not only at the end of the degree, but also in the previous years. The main purpose of this paper is to present and analyse a Project-Based Learning (PBL) semester in which six teams of Industrial Engineering and Management (IEM) students integrate different areas of knowledge, while solving real problems of five companies, emphasizing the technical solutions developed by the students and the feedback provided by the companies. Students' feedback will be also addressed. The main outcomes of this study reveal that most of the technical solutions lie in areas of Lean applications and ergonomic improvement of workplaces. Companies were very pleased with the results of this type of University-Business Cooperation (UBC).This work was funded by COMPETE-POCI-01-0145-FEDER-007043 and FCT-UID-CEC-00319-2013info:eu-repo/semantics/publishedVersio
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