1,474 research outputs found
Comment on "Ferromagnetic film on a superconducting substrate"
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
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.)
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MetriCat: A Representation for Basic and Subordinate-level Classification
An important function of human visual perception is to permit object classification at multiple levels of specificity. For example, we can recognize an object as a "car," (the basic level) a "Ford Mustang" (subordinate level), and "Joe's Mustang" (instance level). Although this capacity is fundamental to human object perception, most computational models of object recognition either focus exclusively on basic-level classification (e.g., Biederman, 1987; Hummel & Biederman, 1992; Hummel & Stankiewicz, 1996) or exclusively on instance-level classification (e.g., Ullman & Basri, 1991; Edelman & Poggio, 1990). A computational account that naturally integrates both levels of classification remains elusive. We describe a general approach to representing numerical properties (e.g., those that characterize object shape) that simultaneously supports both basic and subordinate/instance-level recognition. The account is based on a general nonlinear coding for numerical quantities describing both featural variables (such as degree of curvature and aspect ratio) and configural variables (such as relative position). Used as the input to a classifier with Gaussian receptive fields, this representation supports recognition at multiple levels of specificity, and suggests an account of the role of attention and time in the classification of objects at different levels of abstraction
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
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
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
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)
<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 PrCaMnO strained thin films
We have investigated the magnetic-field-induced phase transition of
charge-ordered (CO) PrCaMnO thin films, deposited onto
(100)-oriented LaAlO and (100)-oriented SrTiO 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 ( 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
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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