oalib

OALib Journal期刊

ISSN: 2333-9721

费用：99美元

投稿

时间不限

( 2024 )

( 2023 )

( 2022 )

( 2021 )

自定义范围…

匹配条件： “Igor Kozhevnikov” ，找到相关结果约9122条。
列表显示的所有文章，均可免费获取
第1页/共9122条
每页显示 条
Single-order operation of lamellar multilayer gratings in the soft x-ray spectral range
Robert van der Meer,Igor Kozhevnikov,Balachander Krishnan,Jurriaan Huskens
AIP Advances , 2013, DOI: 10.1063/1.4774297
Abstract: We demonstrate single-order operation of Lamellar Multilayer Gratings in the soft x-ray spectral range. The spectral resolution was found to be 3.8 times higher than from an unpatterned multilayer mirror, while there were no significant spectral sideband structures adjacent to the main Bragg peak. The measured spectral bandwidths and peak reflectivities were in good agreement with our theoretical calculations.
Creative Processes during a Collaborative Drawing Task in Teams of Different Specializations  [PDF]
Olesya Blazhenkova, Maria Kozhevnikov
Creative Education (CE) , 2020, DOI: 10.4236/ce.2020.119128
Abstract: The present research examined creative drawing processes in teams of gifted adolescents with different educational specializations, including teams with homogeneous (the same specialization) and heterogeneous (mixed specialization) composition. Based on the converging evidence from protocol and Linkography analyses, we identified the differences in frequency and dynamic distribution of distinct creative processes between the different teams specializing in visual art, natural science, humanities, as well as mixed specialization teams. Visualization processes played a crucial role for visual art, science, mixed, but not for humanities teams. All teams except humanities had visual planning earlier in the creative process. Visual artists’ visualization processes developed prominently and continuously throughout all stages of creative production with the main focus on visual aesthetics while for scientists, they developed more discreetly, and in conjunction with understanding of function. Mixed and visual art teams shared many similarities, and they had the highest level of integration between the ideas expressed during their creative processes. Mixed team had higher frequency of organizational processes, indicating coordination and organization challenges due to their diversity. The results of this research show the importance of considering differences in visualization profiles while composing teams of different specializations.
Roughness of level sets of differentiable maps on Heisenberg group
Artem Kozhevnikov
Mathematics , 2011,
Abstract: We investigate metric properties of level sets of horizontally differentiable maps defined on the first Heisenberg group $(\Bbb{H}^1,d_{cc})$ equipped with the standard sub-Riemannian structure. In particular, we present an exhaustive analysis in a new case of a map $F\in C^1_H(\Bbb{H}^1, \Bbb{R}^2)$ with surjective horizontal differential (an analogue of the classical implicit function theorem). Among other results, we show that a level set of such map is locally a simple curve of Hausdorff sub-Riemannian dimension 2, but, surprisingly, in general its two-dimensional Hausdorff measure can be zero or infinity. Therefore, those level sets (called \textsf{vertical curves}) can be of rough nature and not belong to the class of intrinsic regular manifolds.
On complexity of envelopes of piecewise linear functions, unions and intersections of polygons
Pavel Kozhevnikov
Mathematics , 2013,
Abstract: We prove tight upper bounds for the number of vertices of a simple polygon that is the union or the intersection of two simple polygons with given numbers of convex and concave vertices. The similar question on graphs of the lower (or upper) envelope of two continuous piecewise linear functions is considered.
Review: Jenny Phillimore (ed.), Migration and Social Policy
Andrew Kozhevnikov
- , 2018, DOI: 10.1177/0268580918757113d
Abstract:
Soft x-ray reflectometry, hard x-ray photoelectron spectroscopy and transmission electron microscopy investigations of the internal structure of TiO2(Ti)/SiO2/Si stacks
Elena O Filatova, Igor V Kozhevnikov, Andrey A Sokolov, Evgeniy V Ubyivovk, Sergey Yulin, Mihaela Gorgoi and Franz Sch？fers
Science and Technology of Advanced Materials , 2012,
Abstract: We developed a mathematical analysis method of reflectometry data and used it to characterize the internal structure of TiO2/SiO2/Si and Ti/SiO2/Si stacks. Atomic concentration profiles of all the chemical elements composing the samples were reconstructed from the analysis of the reflectivity curves measured versus the incidence angle at different soft x-ray reflection (SXR) photon energies. The results were confirmed by the conventional techniques of hard x-ray photoelectron spectroscopy (HXPES) and high-resolution transmission electron microscopy (HRTEM). The depth variation of the chemical composition, thicknesses and densities of individual layers extracted from SXR and HXPES measurements are in close agreement and correlate well with the HRTEM images.
Abdominal tuberculosis in urgent surgery
Aleksandr P Frolov,Darizhab B Tsoktoev,Elena A Kelchevskaya,Igor E Golub,Igor Y Oleynikov,Mihail A Kozhevnikov,Vladimir A Beloborodov
- , 2019, DOI: https://doi.org/10.3329/bjms.v18i4.42907
Abstract: Objective: This article presents retrospective analysis conducted on the basis of the General Surgery Clinic of the Irkutsk State Medical University (ISMU)
Analysis of Nonlinear Stochastic Systems with Jumps Generated by Erlang Flow of Events  [PDF]
Alexander S. Kozhevnikov, Konstantin A. Rybakov
Open Journal of Applied Sciences (OJAppS) , 2013, DOI: 10.4236/ojapps.2013.31001
Abstract:

In this paper we consider the stochastic systems with jumps (random impulses) generated by Erlang flow of events that lead to discontinuities in paths. These systems may be used in various applications such as a control of complex technical systems, financial mathematics, mathematical biology and medicine. We propose to use a spectral method formalism to the probabilistic analysis problem for the stochastic systems with jumps. This method allows to get a solution of the analysis problem in an explicit form.

On explicit and numerical solvability of parabolic initial-boundary value problems
Alexander Kozhevnikov,Olga Lepsky
Boundary Value Problems , 2006, DOI: 10.1155/bvp/2006/75458
Abstract: A homogeneous boundary condition is constructed for the parabolic equation ( ￠ t+I ￠ ’ ”)u=f in an arbitrary cylindrical domain — ￠ ( ￠ ￠ n being a bounded domain, I and ” being the identity operator and the Laplacian) which generates an initial-boundary value problem with an explicit formula of the solution u. In the paper, the result is obtained not just for the operator ￠ t+I ￠ ’ ”, but also for an arbitrary parabolic differential operator ￠ t+A, where A is an elliptic operator in ￠ n of an even order with constant coefficients. As an application, the usual Cauchy-Dirichlet boundary value problem for the homogeneous equation ( ￠ t+I ￠ ’ ”)u=0 in — ￠ is reduced to an integral equation in a thin lateral boundary layer. An approximate solution to the integral equation generates a rather simple numerical algorithm called boundary layer element method which solves the 3D Cauchy-Dirichlet problem (with three spatial variables).
On explicit and numerical solvability of parabolic initial-boundary value problems
Kozhevnikov Alexander,Lepsky Olga
Boundary Value Problems , 2006,
Abstract: A homogeneous boundary condition is constructed for the parabolic equation in an arbitrary cylindrical domain ( being a bounded domain, and being the identity operator and the Laplacian) which generates an initial-boundary value problem with an explicit formula of the solution . In the paper, the result is obtained not just for the operator , but also for an arbitrary parabolic differential operator , where is an elliptic operator in of an even order with constant coefficients. As an application, the usual Cauchy-Dirichlet boundary value problem for the homogeneous equation in is reduced to an integral equation in a thin lateral boundary layer. An approximate solution to the integral equation generates a rather simple numerical algorithm called boundary layer element method which solves the 3D Cauchy-Dirichlet problem (with three spatial variables).
第1页/共9122条
每页显示 条


Home
Copyright © 2008-2020 Open Access Library. All rights reserved.