1,474 research outputs found

    Comment on "Ferromagnetic film on a superconducting substrate"

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    A superconducting substrate is not able to shrink drastically domains in a ferromagnetic film, contrary to the prediction of Bulaevskii and Chudnovsky [Phys. Rev. B, 63, issue1 (2001)]. This is shown on the basis of the exact solution for the stripe domain structure.Comment: 8 pages, 1 figure, the version published in Phys. Rev.

    It is not OK but it works – unproductive entrepreneurship, the case of Poland

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    The concept of unproductive entrepreneurs was introduced to science by Baumol, who pointed out the differences in business output between countries. Unproductive behaviour of entrepreneurs is often a consequence of ineffective institutions used by entrepreneurs for rent seeking. The aim of this article is to examine subjective norms (S.N.) and attitudes regarding specified types of unproductive entrepreneurship, which in many cases takes the form of unethical or even unlawful behaviour among entrepreneurs in Poland. Examples of such behaviour are: bribery and tax evasion, burdensome lawsuits, often unfounded or lobbying. The structure of the research was based on Baumol’s work while the research model was based on Ajzen’s theory of planned behaviour (T.P.B.). In this article we argue that unproductive entrepreneurship in transforming economies is often forced by inefficient institutions and the desire to avoid bankruptcy. The results of the survey carried out among 270 Polish entrepreneurs indicated a permissive and subjective standard regarding tax evasion when the existence of their business is endangered, and more negative behavioural beliefs (B.B.) regarding the effectiveness of tax evasion than regarding the effectiveness of paying bribes (P.B.)

    An algorithm for preoperative differential diagnostics of parotid tumours on the basis of their dynamic and diffusion-weighted magnetic resonance images: a retrospective analysis of 158 cases

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    Background: To verify the usefulness of a new algorithm for preoperative differential diagnostics of parotid tumours on the basis of their dynamic and diffusion- -weighted magnetic resonance imaging (MRI). Materials and methods: The retrospective analysis included 158 consecutive surgical patients with parotid tumours. Aside from ultrasound-guided fine needle biopsy, the protocol of preoperative evaluation included dynamic and diffusion-weighted MRI. According to the new diagnostic algorithm, the result of fine needle biopsy was considered only in the case of lesions with time to peak enhancement (Tpeak) > 60 s and washout rate (WR) ≤ 30% on dynamic MRI and apparent diffusion coefficient (ADC) ≤ 1.7 × 103 mm/s2 on diffusion-weighted MRI, or those presenting with concomitant lymphadenopathy. The accuracy of this algorithm was verified against final histopathological diagnoses. Results: The new algorithm gave 10 true positive and 2 false positive results, as well as 132 and 14 true and false negative results, respectively. Its sensitivity and specificity (41.7% and 98.5%, respectively) were the same as in the case of fine needle biopsy alone. None of the 59 tumours that were qualified as benign solely on the basis of preoperative MRI turned out to be malignant on postoperative histopathological examination. Conclusions: Interpreted together, dynamic and diffusion-weighted MRIs provide the same accuracy in preoperative differential diagnostics of parotid tumours as fine needle biopsy. This substantiates the use of diagnostic algorithms in which biopsy would serve mostly as a secondary test to verify selected ambiguous radiological diagnoses. (Folia Morphol 2018; 77, 1: 29–35)

    Unconstrained Face Detection and Open-Set Face Recognition Challenge

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    Face detection and recognition benchmarks have shifted toward more difficult environments. The challenge presented in this paper addresses the next step in the direction of automatic detection and identification of people from outdoor surveillance cameras. While face detection has shown remarkable success in images collected from the web, surveillance cameras include more diverse occlusions, poses, weather conditions and image blur. Although face verification or closed-set face identification have surpassed human capabilities on some datasets, open-set identification is much more complex as it needs to reject both unknown identities and false accepts from the face detector. We show that unconstrained face detection can approach high detection rates albeit with moderate false accept rates. By contrast, open-set face recognition is currently weak and requires much more attention.Comment: This is an ERRATA version of the paper originally presented at the International Joint Conference on Biometrics. Due to a bug in our evaluation code, the results of the participants changed. The final conclusion, however, is still the sam

    Electronic structure of the (111) and (-1-1-1) surfaces of cubic BN: A local-density-functional ab initio study

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    We present ab initio local-density-functional electronic structure calculations for the (111) and (-1-1-1) surfaces of cubic BN. The energetically stable reconstructions, namely the N adatom, N3 triangle models on the (111), the (2x1), boron and nitrogen triangle patterns on the (-1-1-1) surface are investigated. Band structure and properties of the surface states are discussed in detail.Comment: 8 pages, 12 figure

    On-site early-warning system for bishkek (Kyrgyzstan)

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    <p>In this work, the development of an on-site early warning system for Bishkek (Kyrgyzstan) is outlined. Several low cost sensors equipped with MEMS accelerometers are installed in eight buildings distributed within the urban area. The different sensing units communicate each other via wireless links and the seismic data are streamed in real-time to the data center using internet. Since each single sensing unit has computing capabilities, software for data processing can be installed to perform decentralized actions. In particular, each sensing unit can perform event detection task and run software for on-site early warning. If a description for the vulnerability of the building is uploaded in the sensing unit, this piece of information can be exploited to introduce the expected probability of damage in the early-warning protocol customized for a specific structure.</p

    High magnetic field transport measurement of charge-ordered Pr0.5_{0.5}Ca0.5_{0.5}MnO3_3 strained thin films

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    We have investigated the magnetic-field-induced phase transition of charge-ordered (CO) Pr0.5_{0.5}Ca0.5_{0.5}MnO3_3 thin films, deposited onto (100)-oriented LaAlO3_3 and (100)-oriented SrTiO3_3 substrates using the pulsed laser deposition technique, by measuring the transport properties with magnetic fields up to 22T. The transition to a metallic state is observed on both substrates by application of a critical magnetic field (HC>10TH_C>10T at 60K). The value of the field required to destroy the charge-ordered insulating state, lower than the bulk compound, depends on both the substrate and the thickness of the film. The difference of the critical magnetic field between the films and the bulk material is explained by the difference of in-plane parameters at low temperature (below the CO transition). Finally, these results confirm that the robustness of the CO state, depends mainly on the stress induced by the difference in the thermal dilatations between the film and the substrate.Comment: 10 pages, 6 figures. To be published in Phys. Rev.

    Priming of plane-rotated objects depends on attention and view familiarity

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    Three experiments investigated the role of attention in visual priming across rotations in the picture plane. Experiment 1 showed that naming latencies increased with the degree of misorientation for objects commonly seen in an upright view (base objects) but not for objects seen familiarly from many views (no-base objects). In Experiment 2, no-base objects revealed a priming pattern identical to that observed previously for left-right reflections (Stankiewicz, Hummel, & Cooper, 1998): Attended objects primed themselves in the same and rotated views, whereas ignored images primed themselves only in the same view, with additive effects of attention and orientation. In Experiment 3 ignored base objects only primed themselves in a familiar (upright) view, indicating that priming only obtains when that image makes contact with object memory. These data challenge theories of object recognition that rely on any single representation of shape and contribute to evidence suggesting holistic (view-like) representations for ignored and analytic (view-insensitive) representations for attended objects
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