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A MONOTONE DOMAIN DECOMPOSITION ALGORITHM FOR SOLVING WEIGHTED AVERAGE APPROXIMATIONS TO NONLINEAR SINGULARLY PERTURBED PARABOLIC PROBLEMS

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Journal of Computational Mathematics 2008年第1期26卷 76-97页

作者： igor boglaev Matthew Hardy Institute of Fundamental Sciences Massey UniversityPrivate Bag 11-222Palmerston NorthNew Zealand Mathematical Sciences Institute Australian National UniversityCanberraAustralia 0200

This paper presents and analyzes a monotone domain decomposition algorithm for solving nonlinear singularly perturbed reaction-diffusion problems of parabolic type. To solve the nonlinear weighted average finite difference scheme for the partial differential equation, we construct a monotone domain decomposition algorithm based on a Schwarz alternating method and a box-domain decomposition. This algorithm needs only to solve linear discrete systems at each iterative step and converges monotonically to the exact solution of the nonlinear discrete problem. domain decomposition algorithm is estimated The rate of convergence of the monotone Numerical experiments are presented.

关键词： Parabolic reaction-diffusion problem Boundary layers O-method Monotone domain decomposition algorithm Uniform convergence

Cortical hem signaling center: functions, development, and potential implications for evolution and brain disorders

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Neural Regeneration Research 2025年第4期20卷 1079-1080页

作者： Victor V.Chizhikov igor Y.Iskusnykh Department of Anatomy and Neurobiology University of Tennessee Health Science CenterMemphisTNUSA

Development of the telencephalon relies upon several signaling centers-localized cellular populations that supply secreted factors to pattern the cortical *** such signaling center is the cortical hem,which arises during embryonic development at the telencephalic dorsal midline,adjacent to the choroid plexus and hippocampal primordium(Figure 1A).While the cortical hem has also been described in reptiles and birds,most of our knowledge about the developmental roles of the cortical hem is derived from the analysis in *** cortical hem produces several types of secreted molecules,including wingless-related integration site(Wnt)and bone morphogenetic(Bmp)*** cortical hem is particularly important for the development of the hippocampus,which is involved in learning and memory,and the neocortex,which is the most complex brain region that mediates multiple types of behavior and higher cognitive functions(Mangale et al.,2008;Dal-Valle-Anton and Borrell,2022).

关键词： epithelium Figure center

Risk Assessment of a Stochastic Service System

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Journal of Systems Science and Systems Engineering 2020年第5期29卷 537-554页

作者： igor Lazov Faculty of Informatics European University Skopje1000 SkopjeMacedonia

A stochastic service system of finite size M is comprised of identical service facilities,including or not a waiting queue,which simultaneously treats N customers,N∈{0,1,…,M}.Depending on the concepts of system information *** system entropy S=£(f),we promote a risk assessment *** definition,the system entropy is the uncertainty associated with the system,and the system expected loss is the risk associated with the ***,accepting the system information as loss function,we can identify risk and uncertainty,associated with the system,using the entropy as risk ***,we differ risk of the system(i.e.,risk observed by an outside observer),risk observed by an arriving customer,and risk observed by a departing customer,giving a separate expression for each ***,these risks are compared with each other,when the system has the same average number E(N)of customers seen by any *** three risk types(together with the three customer means)allow us to distinguish two systems obeying the same probability *** approach enables system operators to choose suitable values for system utilization and size,in view of the three risks *** developed procedure is applied to the information linear system,Erlang loss system,single-server queueing system with discouraged arrivals,Binomial system and Engset loss system.

关键词： Absolute and relative risk uncertainty system information and entropy system utilization stochastic service system

The Functional Role of the Hollow Region of the Butterfly Pyrameis atalanta (L.) Scale

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Journal of Bionic Engineering 2008年第3期5卷 224-230页

作者： igor Kovalev Kinneret College on the Sea of Galilee Emek Hayarden 15132 Israel

Questions concerning the functional role of the hollow region of the butterfly Pyrameis atalanta （L.） scale are experimentally investigated. Attention was initially directed to this problem by observation of the complex microstrucmre of the butterfly scale as well as other studies indicating higher lift on butterfly wings covered with scale. The aerodynamic forces were measured for two oscillating scale models. Results indicated that the air cavity of an oscillating model of the Pyrameis atalanta （L.） scale increased the lift by a factor of 1.15 and reduced the damping coefficients by a factor of 1.38. The modification of the aerodynamic effects on the model of butterfly scale was due to an increase of the virtual air mass, which influenced the body. The hollow region of the scale increased the virtual air mass by a factor of 1.2. The virtual mass of the butterfly scale with the hollow region was represented as the sum of air mass of two imaginary geometrical figures： a circular cylinder around the scale and a right-angled parallelepiped within the hollow region. The interaction mechanism of the butterfly Pyrameis atalanta （L.） scale with a flow was described. This novel interaction mechanism explained most geometrical features of the airpermeable butterfly scale （inverted V-profile of the ridges, nozzle of the tip edge, hollow region, and openings of the upper lamina） and their arrangement.

关键词： bionic butterfly scale hollow region damped coefficient flapping motion virtual mass

Use of GIS technology and cellular automata for modeling multiple socio-economic scenarios of regional spatial development and inter-regional cooperation

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Geo-Spatial Information Science 2023年第1期26卷 71-93页

作者： igor Musikhin Alexander Karpik Department of Photogrammetry and Remote Sensing Siberian State University of Geosystems and TechnologiesNovosibirskRussia Department of Space and Physical Geodesy Siberian State University of Geosystems and TechnologiesNovosibirskRussia

The advancement of effective spatial planning to support sustainable development and interregional cooperation has become an issue of serious concern for regional *** planning research helps to identify economic clusters and analyze their changing spatial patterns,which is important for understanding regional economic space dynamics and poten-tial inter-regional *** support decision-makers in the development of efficient plans of spatial development encompassing the identification of the best-suited territories,a combined Geographic Information System(GIS)based approach to interpret qualitatively expressed multiple socio-economic scenarios in quantitative map-based terms of graded suitability,and a formalized approach to the socio-economic evaluation of the territory is *** on GIS technology coupled with integrated cellular automata decision analysis techniques,the study provides a method that performs socio-economic assessment of the study area according to the generated scenarios of regional spatial and socio-economic *** proposed method is applied to Primorsky and Khabarovsk Krais,located in the Russian Far ***-economic scenarios of spatial development initiated by investors and regional authorities were assessed and *** generated socio-economic scenar-ios illustrate how the unified set of spatial and socio-economic variables can be linked and used to gain insights into inter-regional socio-economic and spatial *** application results demonstrate the advantage of the proposed method in identifying the best-suited unit areas for targeted regional development.

关键词： Geographic Information System(GIS) spatial development socioeconomic scenarios interregional cooperation open source software Cellular Automata(CA)

Uncertainty in satellite remote sensing of snow fraction for water resources management

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Frontiers of Earth Science 2018年第4期12卷 711-727页

作者： igor APPEL TAG LLC WashingtonDistrict of Columbia20024USA

Snow fraction is an important component of land surface models and hydrologic models. Information on snow fraction also improves downstream products retrieved from remote sensing: vertical atmosphere profiles, soil moisture, heat fluxes, etc. The uncertainty of the fractional snow cover estimates must be determined, quantified, and reported to consider the suitability of the product for modeling, data assimilation and other applications. The reflectances of snow and non-snow are characterized by a very significant local variability and also by changes from one scene to another. The local snow and non-snow endmembers are approximated by the Normalized Difference Snow Index with a high accuracy. The magnitudes of snow and non-snow Normalized Difference Snow Indexes are scene-specific and calculated on the fly to retrieve snow fraction. The development of the Normalized Difference Snow Index based algorithms to estimate snow fraction including a scene-specific approach taking local snow and non-snow properties into account is considered an optimal way to fractional snow retrieval from moderate resolution optical remote sensing observations. The Landsat reference data are used to estimate the performance of the fractional snow cover algorithms at moderate resolution and to compare the quality of alternative algorithms. The validation results demonstrate that the performance of the algorithms using Normalized Difference Snow Index has advantages. The advantages achieved in snow fraction retrieval lead to improved estimate of snow water equivalent and changes in snow cover state contributing to better modeling of land surface and hydrologic regime. The success of managing water resources on the whole depends on coordinating described investigations with the works of other researchers developing further enhanced models.

关键词： algorithm remote sensing uncertainty validation snow cover fraction

Life and Death of Stationary Linear Response in Anomalous Continuous Time Random Walk Dynamics

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Communications in Theoretical Physics 2014年第10期61卷 497-504页

作者： igor Goychuk Institute for Physics and Astronomy University of PotsdamKarl-Liebknecht-Str.24/2514476 Potsdam-GolmGermany

Linear theory of stationary response in systems at thermal equilibrium requires to find equilibrium correlation function of unperturbed responding system. Studies of the response of the systems exhibiting anomalously slow dynamics are often based on the continuous time random walk description(CTRW) with divergent mean waiting *** bulk of the literature on anomalous response contains linear response functions like one by Cole-Cole calculated from such a CTRW theory and applied to systems at thermal equilibrium. Here we show within a fairly simple and general model that for the systems with divergent mean waiting times the stationary response at thermal equilibrium is absent,in accordance with some recent studies. The absence of such stationary response(or dying to zero non-stationary response in aging experiments) would confirm CTRW with divergent mean waiting times as underlying physical relaxation mechanism, but reject it otherwise. We show that the absence of stationary response is closely related to the breaking of ergodicity of the corresponding dynamical variable. As an important new result, we derive a generalized Cole-Cole response within ergodic CTRW dynamics with finite waiting time. Moreover, we provide a physically reasonable explanation of the origin and wide presence of 1/f noise in condensed matter for ergodic dynamics close to normal, rather than strongly deviating.

关键词： random walks anomalous response and relaxation stationarity aging 1/f noise

UNIFORM QUADRATIC CONVERGENCE OF A MONOTONE WEIGHTED AVERAGE METHOD FOR SEMILINEAR SINGULARLY PERTURBED PARABOLIC PROBLEMS＊

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Journal of Computational Mathematics 2013年第6期31卷 620-637页

作者： igor Bogluev Institute of Fundamental Sciences Massey University Palmerston North New Zealand

This paper deals with a monotone weighted average iterative method for solving semilinear singularly perturbed parabolic problems. Monotone sequences, based on the ac- celerated monotone iterative method, are constructed for a nonlinear difference scheme which approximates the semilinear parabolic problem. This monotone convergence leads to the existence-uniqueness theorem. An analysis of uniform convergence of the monotone weighted average iterative method to the solutions of the nonlinear difference scheme and continuous problem is given. Numerical experiments are presented.

关键词： Semilinear parabolic problem Singular perturbation Weighted average scheme,Monotone iterative method Uniform convergence.

Tailoring magnetism in semiconductors

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Science China(Physics,Mechanics & Astronomy) 2018年第6期61卷 91-93页

作者： igor Zutic Tong Zhou Department of Physics University at Buffalo State University of New York Buffalo NY 14260 USA

While logic devices in conventional electronics rely on the control of the charged carriers in the semiconductor chips, robust information storage in computer hard drives and magnetic random access memory is implemented using the carriers＇ spin in ferromagnetic metals. A long quest to realize magnetic semiconductors [1-3] can be simply summarized as： 1＋1〉2, in hope that combining the control of charge and spin in a single material would become more than just the sum of its separate parts （charge and spin） and enable new or improved functionalities [3].

关键词：半导体芯片磁力定制计算机硬盘铁磁性逻辑设备信息存储充电