1,903 research outputs found

    New Techniques in Public Housing

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    Wireless Keypads - A New Classroom Technology Using Enhanced Multiple-Choice Questions

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    This article discusses the advantages of using wireless keypads in the Lecture/classroom. This new technology requires multiple-choice (MC) questions to mate with the keypad entry features of these devices. The format of the traditional MC response is constrained to five choices and only one best response is allowed. For this reason, we propose enhancements to the traditional MC question. This enhanced MC question allows as many as ten answers. The answers can vary in their degree of correctness and can be assigned partial credit. By combining wireless keypads and multiple-choice questions, we can readily perform both formative and summative assessments of student learning. Examples and classroom applications are presented.Comment: pdf file, 8 pages,

    Rational Group Decision Making. A random field Ising model at T=0

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    A modified version of a finite random field Ising ferromagnetic model in an external magnetic field at zero temperature is presented to describe group decision making. Fields may have a non-zero average. A postulate of minimum inter-individual conflicts is assumed. Interactions then produce a group polarization along one very choice which is however randomly selected. A small external social pressure is shown to have a drastic effect on the polarization. Individual bias related to personal backgrounds, cultural values and past experiences are introduced via quenched local competing fields. They are shown to be instrumental in generating a larger spectrum of collective new choices beyond initial ones. In particular, compromise is found to result from the existence of individual competing bias. Conflict is shown to weaken group polarization. The model yields new psycho-sociological insights about consensus and compromise in groups.Comment: 25 pages, late

    On V_ud determination from kaon decays

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    The pion beta decay pi^+ -> pi^0 e^+ nu proceeds through pure weak vector hadronic currents and, therefore, the theoretical prediction for it is more reliable than for the processes with axial-vector current contribution. For example, recently the pion beta decay has been used for V_ud determination. The main aim of this letter is to point that kaon beta decay K^0 -> K^+(pi^+ pi^0) e^- nu-bar analogously can be used for this purpose.Comment: 3 pages, no figures, one reference adde

    The Role of Lambda(1405) in Kaon-Proton Interactions

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    S-wave KpK^-p scattering into various channels near threshold are analyzed in heavy-baryon chiral perturbation theory with Λ(1405)\Lambda (1405) introduced as an independent field. This is the approach that predicted the critical density 2<=ρc/ρ0<=32<=\rho_c/\rho_0 <=3 for negatively charged kaon condensation. We show that chiral perturbation expansion treating the Λ(1405)\Lambda (1405) as elementary is consistent with {\it all} threshold data including a double-charge-exchange process suppressed at leading order of chiral expansion in the absence of the Λ(1405)\Lambda (1405). We also discuss S-wave K+pK^+ p scattering phase shifts at low energy.Comment: 12 pages, epsfig.sty, 1 figure (uuencoded

    Study of muons near shower cores at sea level using the E594 neutrino detector

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    The E594 neutrino detector has been used to study the lateral distribution of muons of energy 3 GeV near shower cores. The detector consists of a 340 ton fine grain calorimeter with 400,000 cells of flash chamber and dimensions of 3.7 m x 20 m x 3.7 m (height). The average density in the calorimeter is 1.4 gm/sq cm, and the average Z is 21. The detector was triggered by four 0.6 sq m scintillators placed immediately on the top of the calorimeter. The trigger required at least two of these four counters. The accompanying extensive air showers (EAS) was sampled by 14 scintillation counters located up to 15 m from the calorimeter. Several off line cuts have been applied to the data. Demanding five particles in at least two of the trigger detectors, a total of 20 particles in all of them together, and an arrival angle for the shower 450 deg reduced the data sample to 11053 events. Of these in 4869 cases, a computer algorithm found at least three muons in the calorimeter

    The composition of cosmic rays near the Bend (10 to the 15th power eV) from a study of muons in air showers at sea level

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    The distribution of muons near shower cores was studied at sea level at Fermilab using the E594 neutrino detector to sample the muon with E testing 3 GeV. These data are compared with detailed Monte Carlo simulations to derive conclusions about the composition of cosmic rays near the bend in the all particle spectrum. Monte Carlo simulations generating extensive air showers (EAS) with primary energy in excess of 50 TeV are described. Each shower record contains details of the electron lateral distribution and the muon and hadron lateral distributions as a function of energy, at the observation level of 100g/cm. The number of detected electrons and muons in each case was determined by a Poisson fluctuation of the number incident. The resultant predicted distribution of muons, electrons, the rate events are compared to those observed. Preliminary results on the rate favor a heavy primary dominated cosmic ray spectrum in energy range 50 to 1000 TeV

    Proposed New Antiproton Experiments at Fermilab

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    Fermilab operates the world's most intense source of antiprotons. Recently various experiments have been proposed that can use those antiprotons either parasitically during Tevatron Collider running or after the Tevatron Collider finishes in about 2010. We discuss the physics goals and prospects of the proposed experiments.Comment: 6 pages, 2 figures, to appear in Proceedings of IXth International Conference on Low Energy Antiproton Physics (LEAP'08), Vienna, Austria, September 16 to 19, 200

    Distance to the Active Galaxy NGC 6951 via the Type Ia Supernova 2000E

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    CCD-photometry and low-resolution spectroscopy of the bright supernova SN 2000E in NGC 6951 are presented. Both the light curve extending up to 150 days past maximum and the spectra obtained at 1 month past maximum confirm that SN 2000E is of Type Ia. The reddening of SN 2000E is determined as E(B-V)=0.36+/-0.15, its error is mainly due to uncertainties in the predicted SN (B-V) colour at late epochs. The V(RI)_C light curves are analyzed with the Multi-Colour Light Curve Shape (MLCS) method. The shape of the late light curve suggests that SN 2000E was overluminous by about 0.5 mag at maximum comparing with a fiducial SN Ia. This results in an updated distance of 33+/-8 Mpc of NGC 6951 (corrected for interstellar absorption). The SN-based distance modulus is larger by about +0.7 mag than the previous Tully-Fisher estimates. However, possible systematic errors due to ambiguities in the reddening determination and estimates of the maximum luminosity of SN 2000E may plague the present distance measurement.Comment: 9 p., 5 figs, accepted for publication in A&A. A reference correcte

    A Keyword-driven approach for generating OWL DL conformance test data

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    The conformance of semantic technologies has to be systematically evaluated to measure and verify the real adherence of these technologies to the Semantic Web standards. Currente valuations of semantic technology conformance are not exhaustive enough and do not directly cover user requirements and use scenarios, which raises the need for a simple, extensible and parameterizable method to generate test data for such evaluations. To address this need, this paper presents a keyword-driven approach for generating ontology language conformance test data that can be used to evaluate semantic technologies, details the definition of a test suite for evaluating OWL DL conformance using this approach,and describes the use and extension of this test suite during the evaluation of some tools
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