823 research outputs found

    A C++ Program for the Cramér-Von Mises Two-Sample Test

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    As larger sets of high-throughput data in genomics and proteomics become more readily available, there is a growing need for fast algorithms designed to compute exact p values of distribution-free statistical tests. We present a program for computing the exact distribution of the two-sample Cramér-von Mises test statistic under the null hypothesis that the two samples are drawn from the same continuous distribution. The program makes it possible to handle substantially larger sample sizes than earlier proposed computational tools. The C++ source code for the program is published with this paper, and an R package is under development.

    Control of the mean number of false discoveries, Bonferroni and stability of multiple testing

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    The Bonferroni multiple testing procedure is commonly perceived as being overly conservative in large-scale simultaneous testing situations such as those that arise in microarray data analysis. The objective of the present study is to show that this popular belief is due to overly stringent requirements that are typically imposed on the procedure rather than to its conservative nature. To get over its notorious conservatism, we advocate using the Bonferroni selection rule as a procedure that controls the per family error rate (PFER). The present paper reports the first study of stability properties of the Bonferroni and Benjamini--Hochberg procedures. The Bonferroni procedure shows a superior stability in terms of the variance of both the number of true discoveries and the total number of discoveries, a property that is especially important in the presence of correlations between individual pp-values. Its stability and the ability to provide strong control of the PFER make the Bonferroni procedure an attractive choice in microarray studies.Comment: Published at http://dx.doi.org/10.1214/07-AOAS102 in the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Equation of state of classical Coulomb plasma mixtures

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    We develop analytic approximations of thermodynamic functions of fully ionized nonideal electron-ion plasma mixtures. In the regime of strong Coulomb coupling, we use our previously developed analytic approximations for the free energy of one-component plasmas with rigid and polarizable electron background and apply the linear mixing rule (LMR). Other thermodynamic functions are obtained through analytic derivation of this free energy. In order to obtain an analytic approximation for the intermediate coupling and transition to the Debye-Hueckel limit, we perform hypernetted-chain calculations of the free energy, internal energy, and pressure for mixtures of different ion species and introduce a correction to the LMR, which allows a smooth transition from strong to weak Coulomb coupling in agreement with the numerical results.Comment: 6 pages, 7 figures; Phys. Rev. E. In v.2 after proofreading, minor typos are fixe

    Effects of Spatial Dispersion on Reflection from Mushroom-type Artificial Impedance Surfaces

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    Several recent works have emphasized the role of spatial dispersion in wire media, and demonstrated that arrays of parallel metallic wires may behave very differently from a uniaxial local material with negative permittivity. Here, we investigate using local and non-local homogenization methods the effect of spatial dispersion on reflection from the mushroom structure introduced by Sievenpiper. The objective of the paper is to clarify the role of spatial dispersion in the mushroom structure and demonstrate that under some conditions it is suppressed. The metamaterial substrate, or metasurface, is modeled as a wire medium covered with an impedance surface. Surprisingly, it is found that in such configuration the effects of spatial dispersion may be nearly suppressed when the slab is electrically thin, and that the wire medium can be modeled very accurately using a local model. This result paves the way for the design of artificial surfaces that exploit the plasmonic-type response of the wire medium slab.Comment: submitted for publication, under revie

    Economic crime and problem of complicity understanding

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    In the articles expediency and performance of the penal statute can and must be caused first of all by social nature factors which in interaction with criminal precepts of law can yield positive result in counteraction to economic crimes are viewed. The essential factor of increased criminality is violation of balance of interests: public, institutional and personal. It is known that domination in economic and other spheres of life of group interests of society and concentration of fixed assets of production in hands of rather small amount of people doesn't promote forming mass sense of justice and law abiding at all. These reasons generate counteraction to the current criminal legal norms.peer-reviewe

    Transmission through stacked 2D periodic distributions of square conducting patches

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    In this paper, we study the transmissivity of electromagnetic waves through stacked two-dimensional printed periodic arrays of square conducting patches. An analytical circuit-like model is used for the analysis. The model accounts for the details of the transmission spectrum provided that the period of the unit cell of each patterned layer is well below the wavelength in the dielectric slabs separating the printed surfaces. In particular, we analyze the low-pass band and rejection band behavior of the multilayer structure, and the results are validated by comparison with a computationally intensive finite element commercial electromagnetic solver. The limiting case of an infinite periodic structure is analytically solved and the corresponding band structure is used to explain the passband/stopband behavior of finite structures. In addition, we study in depth the elementary unit cell consisting of a single dielectric slab coated by two metal patch arrays, and its resonance behavior is explained in terms of Fabry-Pérot resonances when the electrical thickness of the slab is large enough. In such case, the concept of equivalent thickness of the equivalent ideal Fabry-Pérot resonator is introduced. For electrically thinner slabs it is also shown that the analytical model is still valid, and its corresponding first transmission peak is explained in terms of a lumped-circuit LC resonance.Ministerio de Ciencia e Innovación TEC2010-16948, CSD2008-00066Junta de Andalucía P09-TIC-459

    Causative Role of Ureaplasma Urealyticum and other Sexually Transmitted Infections in the Urethral Meatus Polyp Development in Women

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    The objective of this study was the investigation of the influence of ureaplasmal infection on the development of urethral meatus polyps in women. The article presents the results of the examination of women with chronic cystitis and urethritis over a 0.5- to 5-year duration, complicated by the presence of urethral meatus polyps and associated with concomitant Ureaplasma urealyticum and other sexually transmitted infections (STI). This was based on the culture analysis of the cervical and urethral content, and PCR-diagnostics of STI, as well as a complex pathomorphologic study of the resected polyps, including electron microscopy. In this study, 98 women between 45 and 60 years (52.5±4.9 years) were examined, who had undergone radiowave resection of the polyps: 52 women were infected by STI, including Ureaplasma urealyticum, Mycoplasma genitalium, Mycoplasma hominis, Chlamydia trachomatis and Trichomonas vaginalis, while the remaining 46 women had been diagnosed as not having STI. According to the culture results in the women with STI, U. urealyticum was identified as a monoinfection in 69% of cases, while in the remaining 31% of cases it was evident in the form of mixed infections, mainly in association with Mycoplasma hominis (17.5%) and Trichomonas vaginalis (13.5%). Pathomorphological examination of the urethral meatus polyps of the women with U. urealyticum and other STI demonstrated the proliferative character of the remodeling of the surface epithelium with hyperplasia, acanthosis, and keratinization of the stratified squamous epithelium and synchronous changes in the underlying connective tissue - impaired microcirculation and the diffuse inflammatory cell infiltrates with transepithelial leukopedesis. Using electron microscopy in the fibroblasts and plasma cells of the resected polyps the markers of U. urealyticum were detected in patients with negative results of the bacteriological diagnostic methods

    Circuit modeling of multiband high-impedance surface absorbers in the microwave regime

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    In this paper, we present a simple circuit model to study the absorption of electromagnetic waves by a multilayer structure with a high impedance surface in the microwave regime. The absorber consists of a stack of two-dimensional arrays of sub-wavelength meshes or patches separated by dielectric slabs and backed by a metallic ground plane, with a single resistive sheet placed on the top layer. We observe the appearance of low-frequency resonances of total absorption, which have been identified as the resonances of Fabry-Pérot type associated with the individual reactively loaded dielectric slabs (that are strongly coupled through the subwavelength grids). It is shown that these resonances lie within certain characteristic frequency band defined by the structural parameters of the absorber. The observed resonances are characterized by studying the electromagnetic field behavior using the circuit model and full-wave numerical program. In addition, we show that the patch array absorber provides stable resonances with respect to the angle and the polarization of obliquely incident plane wavesMinisterio de Ciencia e Innovación TEC2010-16948, CSD2008-00066Junta de Andalucía TIC-459
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