4,591 research outputs found

    Can a workspace help to overcome the query formulation problem in image retrieval?

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    We have proposed a novel image retrieval system that incorporates a workspace where users can organise their search results. A task-oriented and user-centred experiment has been devised involving design professionals and several types of realistic search tasks. We study the workspace’s effect on two aspects: task conceptualisation and query formulation. A traditional relevance feedback system serves as baseline. The results of this study show that the workspace is more useful with respect to both of the above aspects. The proposed approach leads to a more effective and enjoyable search experience

    Effective potential for composite operators and for an auxiliary scalar field in a Nambu-Jona-Lasinio model

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    We derive the effective potentials for composite operators in a Nambu-Jona-Lasinio (NJL) model at zero and finite temperature and show that in each case they are equivalent to the corresponding effective potentials based on an auxiliary scalar field. The both effective potentials could lead to the same possible spontaneous breaking and restoration of symmetries including chiral symmetry if the momentum cutoff in the loop integrals is large enough, and can be transformed to each other when the Schwinger-Dyson (SD) equation of the dynamical fermion mass from the fermion-antifermion vacuum (or thermal) condensates is used. The results also generally indicate that two effective potentials with the same single order parameter but rather different mathematical expressions can still be considered physically equivalent if the SD equation corresponding to the extreme value conditions of the two potentials have the same form.Comment: 7 pages, no figur

    User Authentication in Smartphones for Telehealth

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    Many functions previously conducted on desktop computers are now performed on smartphones. Smartphones provide convenience, portability, and connectivity.  When smartphones are used in the conduct of telehealth, sensitive data is invariably accessed, rendering the devices in need of user authentication to ensure data protection. User authentication of smartphones can help mitigate potential Health Insurance Portability and Accountability Act (HIPAA) breaches and keep sensitive patient information protected, while also facilitating the convenience of smartphones within everyday life and healthcare. This paper presents and examines several types of authentication methods available to smartphone users to help ensure security of sensitive data from attackers. The applications of these authentication methods in telehealth are discussed. Keywords: Authentication, Biometrics, HIPAA, Mobile security, Telehealt

    Mixing-induced CP violating sources for electroweak baryogenesis from a semiclassical approach

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    The effects of flavor mixing in electroweak baryogenesis is investigated in a generalized semiclassical WKB approach. Through calculating the nonadiabatic corrections to the particle currents it is shown that extra CP violation sources arise from the off-diagonal part of the equation of motion of particles moving inside the bubble wall. This type of mixing-induced source is of the first order in derivative expansion of the Higgs condensate, but is oscillation suppressed. The numerical importance of the mixing-induced source is discussed in the Minimal Supersymmetric Standard Model and compared with the source term induced by semiclassical force. It is found that in a large parameter space where oscillation suppression is not strong enough, the mixing-induced source can dominate over that from the semiclassical force.Comment: 19 pp, 2 figs, 1 table, some comments added, to appear in Eur.Phys.J.

    Semiparametrically point-optimal hybrid rank tests for unit roots

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    We propose a new class of unit root tests that exploits invariance properties in the Locally Asymptotically Brownian Functional limit experiment associated to the unit root model. The invariance structures naturally suggest tests that are based on the ranks of the increments of the observations, their average and an assumed reference density for the innovations. The tests are semiparametric in the sense that they are valid, that is, have the correct (asymptotic) size, irrespective of the true innovation density. For a correctly specified reference density, our test is point-optimal and nearly efficient. For arbitrary reference densities, we establish a Chernoff–Savage-type result, that is, our test performs as well as commonly used tests under Gaussian innovations but has improved power under other, for example, fat-tailed or skewed, innovation distributions. To avoid nonparametric estimation, we propose a simplified version of our test that exhibits the same asymptotic properties, except for the Chernoff–Savage result that we are only able to demonstrate by means of simulations

    Domain movement in rabbit muscle adenylate kinase might involve proline isomerization

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    AbstractThe fluorescence probe, 8-anilino-1-naphthalenesulfonic acid (ANS), was used to monitor the induced-fit conformational movement in rabbit muscle adenylate kinase. In 50 mM Tris-HCl buffer (pH 8.1), the time course of ANS binding to rabbit muscle adenylate kinase is a biphasic process. The fast phase completes within the dead-time of the stopped-flow equipment used (about 15 ms), while the slow phase ends in about 10 minutes. In the presence of 2.0 μM peptidyl prolyl cis/trans-isomerase, the rate constant of the slow phase reaction is accelerated about 2.4-fold, suggesting that the domain movement during ANS binding to rabbit muscle adenylate kinase may involve proline isomerization. The activation energy of the slow phase was determined to be 74.6 kJ/mol, which is comparable to the activation energy of proline cis/trans-isomerization (about 80 kJ/mol)

    An explorative study of interface support for image searching

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    In this paper we study interfaces for image retrieval systems. Current image retrieval interfaces are limited to providing query facilities and result presentation. The user can inspect the results and possibly provide feedback on their relevance for the current query. Our approach, in contrast, encourages the user to group and organise their search results and thus provide more fine-grained feedback for the system. It combines the search and management process, which - according to our hypothesis - helps the user to onceptualise their search tasks and to overcome the query formulation problem. An evaluation, involving young design-professionals and di®erent types of information seeking scenarios, shows that the proposed approach succeeds in encouraging the user to conceptualise their tasks and that it leads to increased user satisfaction. However, it could not be shown to increase performance. We identify the problems in the current setup, which when eliminated should lead to more effective searching overall

    A Systematic Review of Research Studies Examining Telehealth Privacy and Security Practices Used By Healthcare Providers

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    The objective of this systematic review was to systematically review papers in the United States that examine current practices in privacy and security when telehealth technologies are used by healthcare providers. A literature search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P). PubMed, CINAHL and INSPEC from 2003 – 2016 were searched and returned 25,404 papers (after duplications were removed). Inclusion and exclusion criteria were strictly followed to examine title, abstract, and full text for 21 published papers which reported on privacy and security practices used by healthcare providers using telehealth.  Data on confidentiality, integrity, privacy, informed consent, access control, availability, retention, encryption, and authentication were all searched and retrieved from the papers examined. Papers were selected by two independent reviewers, first per inclusion/exclusion criteria and, where there was disagreement, a third reviewer was consulted. The percentage of agreement and Cohen’s kappa was 99.04% and 0.7331 respectively. The papers reviewed ranged from 2004 to 2016 and included several types of telehealth specialties. Sixty-seven percent were policy type studies, and 14 percent were survey/interview studies. There were no randomized controlled trials. Based upon the results, we conclude that it is necessary to have more studies with specific information about the use of privacy and security practices when using telehealth technologies as well as studies that examine patient and provider preferences on how data is kept private and secure during and after telehealth sessions.Keywords: Computer security, Health personnel, Privacy, Systematic review, Telehealth

    Scaling exponents and clustering coefficients of a growing random network

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    The statistical property of a growing scale-free network is studied based on an earlier model proposed by Krapivsky, Rodgers, and Redner [Phys. Rev. Lett. 86, 5401 (2001)], with the additional constraints of forbidden of self-connection and multiple links of the same direction between any two nodes. Scaling exponents in the range of 1-2 are obtained through Monte Carlo simulations and various clustering coefficients are calculated, one of which, CoutC_{\rm out}, is of order 10110^{-1}, indicating the network resembles a small-world. The out-degree distribution has an exponential cut-off for large out-degree.Comment: six pages, including 5 figures, RevTex 4 forma

    Spin dynamics in high-mobility two-dimensional electron systems

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    Understanding the spin dynamics in semiconductor heterostructures is highly important for future semiconductor spintronic devices. In high-mobility two-dimensional electron systems (2DES), the spin lifetime strongly depends on the initial degree of spin polarization due to the electron-electron interaction. The Hartree-Fock (HF) term of the Coulomb interaction acts like an effective out-of-plane magnetic field and thus reduces the spin-flip rate. By time-resolved Faraday rotation (TRFR) techniques, we demonstrate that the spin lifetime is increased by an order of magnitude as the initial spin polarization degree is raised from the low-polarization limit to several percent. We perform control experiments to decouple the excitation density in the sample from the spin polarization degree and investigate the interplay of the internal HF field and an external perpendicular magnetic field. The lifetime of spins oriented in the plane of a [001]-grown 2DES is strongly anisotropic if the Rashba and Dresselhaus spin-orbit fields are of the same order of magnitude. This anisotropy, which stems from the interference of the Rashba and the Dresselhaus spin-orbit fields, is highly density-dependent: as the electron density is increased, the kubic Dresselhaus term becomes dominant and reduces the anisotropy.Comment: 13 pages, 6 figure
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