749 research outputs found

    Comparing Identity Management Frameworks in a Business Context

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    Sewability of air-jet textured sewing threads in denim

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    Sewability of a fabric depends on the fabric low-stress mechanical properties, sewing thread properties and the sewing machine settings. This paper investigates the sewability of denim fabrics stitched with air-jet textured sewing thread. It was found that the fabric formability is dependent on the fabric weight. Fabric formability was higher for the heavyweight fabrics and lower for the lightweight fabrics. The overall bending rigidity was the lowest for the denim with the lowest formability and weight. Polyester air-jet textured sewing threads resulted in higher seam efficiency and seam pucker, but lower needle cutting index compared to Polyester/Viscose air-jet textured sewing thread. In weft direction the seam efficiency was higher, whereas in warp direction the needle cutting index was higher for all the fabrics

    Measurement of the Positive Muon Lifetime and Determination of the Fermi Constant to Part-per-Million Precision

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    We report a measurement of the positive muon lifetime to a precision of 1.0 parts per million (ppm); it is the most precise particle lifetime ever measured. The experiment used a time-structured, low-energy muon beam and a segmented plastic scintillator array to record more than 2 x 10^{12} decays. Two different stopping target configurations were employed in independent data-taking periods. The combined results give tau_{mu^+}(MuLan) = 2196980.3(2.2) ps, more than 15 times as precise as any previous experiment. The muon lifetime gives the most precise value for the Fermi constant: G_F(MuLan) = 1.1663788 (7) x 10^-5 GeV^-2 (0.6 ppm). It is also used to extract the mu^-p singlet capture rate, which determines the proton's weak induced pseudoscalar coupling g_P.Comment: Accepted for publication in Phys. Rev. Let

    Improved Measurement of the Positive Muon Lifetime and Determination of the Fermi Constant

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    The mean life of the positive muon has been measured to a precision of 11 ppm using a low-energy, pulsed muon beam stopped in a ferromagnetic target, which was surrounded by a scintillator detector array. The result, tau_mu = 2.197013(24) us, is in excellent agreement with the previous world average. The new world average tau_mu = 2.197019(21) us determines the Fermi constant G_F = 1.166371(6) x 10^-5 GeV^-2 (5 ppm). Additionally, the precision measurement of the positive muon lifetime is needed to determine the nucleon pseudoscalar coupling g_P.Comment: As published version (PRL, July 2007

    CROO: A universal infrastructure and protocol to detect identity fraud

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    Identity fraud (IDF) may be defined as unauthorized exploitation of credential information through the use of false identity. We propose CROO, a universal (i.e. generic) infrastructure and protocol to either prevent IDF (by detecting attempts thereof), or limit its consequences (by identifying cases of previously undetected IDF). CROO is a capture resilient one-time password scheme, whereby each user must carry a personal trusted device used to generate one-time passwords (OTPs) verified by online trusted parties. Multiple trusted parties may be used for increased scalability. OTPs can be used regardless of a transaction’s purpose (e.g. user authentication or financial payment), associated credentials, and online or on-site nature; this makes CROO a universal scheme. OTPs are not sent in cleartext; they are used as keys to compute MACs of hashed transaction information, in a manner allowing OTP-verifying parties to confirm that given user credentials (i.e. OTP-keyed MACs) correspond to claimed hashed transaction details. Hashing transaction details increases user privacy. Each OTP is generated from a PIN-encrypted non-verifiable key; this makes users’ devices resilient to off-line PIN-guessing attacks. CROO’s credentials can be formatted as existing user credentials (e.g. credit cards or driver’s licenses)

    Risk factors for delayed presentation and referral of symptomatic cancer: Evidence for common cancers

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    Background:It has been suggested that the known poorer survival from cancer in the United Kingdom, compared with other European countries, can be attributed to more advanced cancer stage at presentation. There is, therefore, a need to understand the diagnostic process, and to ascertain the risk factors for increased time to presentation.Methods:We report the results from two worldwide systematic reviews of the literature on patient-mediated and practitioner-mediated delays, identifying the factors that may influence these.Results:Across cancer sites, non-recognition of symptom seriousness is the main patient-mediated factor resulting in increased time to presentation. There is strong evidence of an association between older age and patient delay for breast cancer, between lower socio-economic status and delay for upper gastrointestinal and urological cancers and between lower education level and delay for breast and colorectal cancers. Fear of cancer is a contributor to delayed presentation, while sanctioning of help seeking by others can be a powerful mediator of reduced time to presentation. For practitioner delay, ‘misdiagnosis’ occurring either through treating patients symptomatically or relating symptoms to a health problem other than cancer, was an important theme across cancer sites. For some cancers, this could also be linked to inadequate patient examination, use of inappropriate tests or failing to follow-up negative or inconclusive test results.Conclusion:Having sought help for potential cancer symptoms, it is therefore important that practitioners recognise these symptoms, and examine, investigate and refer appropriately. © 2009 Cancer Research UK All rights reserved

    Recoil Polarization Measurements of the Proton Electromagnetic Form Factor Ratio to Q^2 = 8.5 GeV^2

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    Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dynamics of the nucleon's quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this letter, we report new measurements of the proton electromagnetic form factor ratio using the recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5 GeV2. By extending the range of Q2 for which GEp is accurately determined by more than 50%, these measurements will provide significant constraints on models of nucleon structure in the non-perturbative regime

    Absorption of the ω\omega and ϕ\phi Mesons in Nuclei

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    Due to their long lifetimes, the ω\omega and ϕ\phi mesons are the ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. During the E01-112 experiment at the Thomas Jefferson National Accelerator Facility, the mesons were photoproduced from 2^{2}H, C, Ti, Fe, and Pb targets. This paper reports the first measurement of the ratio of nuclear transparencies for the e+ee^{+}e^{-} channel. The ratios indicate larger in-medium widths compared with what have been reported in other reaction channels.Comment: 6 pages, 4 figure

    Differential cross sections and recoil polarizations for the reaction gamma p -> K+ Sigma0

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    High-statistics measurements of differential cross sections and recoil polarizations for the reaction γpK+Σ0\gamma p \rightarrow K^+ \Sigma^0 have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies (s\sqrt{s}) from 1.69 to 2.84 GeV, with an extensive coverage in the K+K^+ production angle. Independent measurements were made using the K+pπK^{+}p\pi^{-}(γ\gamma) and K+pK^{+}p(π,γ\pi^-, \gamma) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR and LEPS results, while offering better statistical precision and a 300-MeV increase in s\sqrt{s} coverage. Above s2.5\sqrt{s} \approx 2.5 GeV, tt- and uu-channel Regge scaling behavior can be seen at forward- and backward-angles, respectively. Our recoil polarization (PΣP_\Sigma) measurements represent a substantial increase in kinematic coverage and enhanced precision over previous world data. At forward angles we find that PΣP_\Sigma is of the same magnitude but opposite sign as PΛP_\Lambda, in agreement with the static SU(6) quark model prediction of PΣPΛP_\Sigma \approx -P_\Lambda. This expectation is violated in some mid- and backward-angle kinematic regimes, where PΣP_\Sigma and PΛP_\Lambda are of similar magnitudes but also have the same signs. In conjunction with several other meson photoproduction results recently published by CLAS, the present data will help constrain the partial wave analyses being performed to search for missing baryon resonances.Comment: 23 pages, 17 figure
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