http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A LOCAL-GLOBAL VERSION OF A STEPSIZE CONTROL FOR RUNGE-KUTTA METHODS
Kulikov, G.Yu 한국전산응용수학회 2000 Journal of applied mathematics & informatics Vol.7 No.2
In this paper we develop a new procedure to control stepsize for Runge- Kutta methods applied to both ordinary differential equations and semi-explicit index 1 differential-algebraic equation In contrast to the standard approach, the error control mechanism presented here is based on monitoring and controlling both the local and global errors of Runge- Kutta formulas. As a result, Runge-Kutta methods with the local-global stepsize control solve differential of differential-algebraic equations with any prescribe accuracy (up to round-off errors)
REVISION OF THE THEORY OF SYMMETRIC ONE-STEP METHODS FOR ORDINARY DIFFERENTIAL EQUATIONS
Kulikov, G.Yo. 한국전산응용수학회 1998 Journal of applied mathematics & informatics Vol.5 No.3
In this paper we develop a new theory of adjoint and symmetric method in the class of general implicit one-step fixed-stepsize methods. These methods arise from simple and natral def-initions of the concepts of symmetry and adjointness that provide a fruitful basis for analysis. We prove a number of theorems for meth-ods having these properties and show in particular that only the symmetric methods possess a quadratic asymptotic expansion of the global error. In addition we give a very simple test to identify the symmetric methods in practice.
Kulikov, G.Yu,Shindin, S.K. 한국전산응용수학회 1999 Journal of applied mathematics & informatics Vol.6 No.3
In this paper we develop a now procedure to control stepsize for linear multistep methods applied to semi-explicit index 1 differential-algebraic equations. in contrast to the standard approach the error control mechanism presented here is based on monitoring and contolling both the local and global errors of multistep formulas. As a result such methods with the local-global stepsize control solve differential-algebraic equation with any prescribed accuracy (up to round-off errors). For implicit multistep methods we give the minimum number of both full and modified Newton iterations allowing the iterative approxima-tions to be correctly used in the procedure of the local-global stepsize control. We also discuss validity of simple iterations for high accuracy solving differential-algebraic equations. Numerical tests support the the-oretical results of the paper.
Kulikov, G.Yu. 한국전산응용수학회 1997 Journal of applied mathematics & informatics Vol.4 No.2
We consider three classes of numerical methods for solv-ing the semi-explicit differential-algebraic equations of index 1 and higher. These methods use implicit multistep fixed stepsize methods and several iterative processes including simple iteration, full a2nd modified Newton iteration. For these methods we prove convergence theorems and derive error estimates. We consider different ways of choosing initial approximations for these iterative methods and in-vestigate their efficiency in theory and practice.
Tsarist Business: State-owned Enterprises in the Late Russian Empire
Volodymyr Kulikov,Martin Kragh 한국외국어대학교(글로벌캠퍼스) 러시아연구소 2021 REGION Vol.10 No.2
The role of the state in the industrialization of the late Russian Empire has been a recurrent topic in historiography. Scholars have studied certain seg- ments of state-owned entrepreneurship but have not taken a holistic approach to enterprises run or controlled by central or local government. This article draws on statistical yearbooks and other primary sources to address this gap in scholarship. It demonstrates that while Tsarist Russia had a diverse public sector, it employed no more than 10 percent of all economically active workers in all areas apart from public administration, the military, education, human health, and social work. The government kept certain enterprises in its owner- ship for various reasons, such as fiscal correction, regional development, and defense. Although the economic footprint of the state was considerable, there is no evidence that its role was significantly more prominent in the Russian case than elsewhere in Europe. The financial performance of most state-owned enterprises was poor; they were less efficient than their European counterparts and compared to private enterprises with a similar profile operating in Russia.
Numerical modeling of technological stresses in crystallizing viscoelastic polymer
R. G. Kulikov,T. G. Kulikova,N. A. Trufanov 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.11
Mathematical model of mechanical behavior of viscoelastic bodies in complex stress state with regard to phase (crystallization) transitions, which describes technological stress field formation regularities in manufacturing polymer articles, is considered. Constitutive relationships describing stress and strain tensors correlation in a wide temperature range, including crystallization temperatures, are suggested. The thermal mechanics boundary-value problem that includes the obtained relationships is formulated. Algorithms of numerical realization of the temperature-conversion problem and the crystallizing system stress-strain state definition problem for an axisymmetric case are examined. Numerical realization features of the mechanical problem solution are discussed. The problem of technological stresses formation during steel and polyethylene tubes permanent connection manufacturing has been solved as the mathematical model application.
Industrial Heritage and Its Multiple Uses in Donbas, Ukraine
Iryna Sklokina,Volodymyr Kulikov 한국외국어대학교(글로벌캠퍼스) 러시아연구소 2021 REGION Vol.10 No.1
The article analyzes the heritagization of industrial culture in Ukraine’s Do- netsk and Luhansk oblasts from the early 20th century until the 2010s. It is based on participant observation, analysis of media discourse, and 24 semi- structured interviews with local historians, museum employees, and other agents of industrial heritagization, collected between 2016 and 2021. The article argues that changing political, social, and cultural contexts, as well as the shifting balance of power between the main organizations for heritage preservation has resulted in the selective representation of the region’s past. It demonstrates that preservationist and utilitarian (political or economic) approaches have been dominant, and that future-oriented initiatives are still few and far between. The authors argue for the need for more forward-ori- ented thinking in dealings with the present and future of Donbas’s industrial heritage.
Plasticization for melt viscosity reduction of melt processable carbon fiber precursor
Batchelor, B.L.,Mahmood, S.F.,Jung, M.,Shin, H.,Kulikov, O.V.,Voit, W.,Novak, B.M.,Yang, D.J. Pergamon Press ; Elsevier Science Ltd 2016 Carbon Vol.98 No.-
<P>Fibers of polyacrylonitrile (PAN), or commonly referred to as acrylic fibers, are found to have many applications. Acrylic fibers are used as a textile medium for high quality and high performance yarns and fabrics, and also as the main supply of precursors for carbon fibers. The main reason of its use as carbon fiber precursor is that the polymer gives high mechanical properties with high carbon yield compared to other polymers. However, a major issue with current carbon fiber production from PAN is the use of a solvent spinning process for the preparation of polymer fiber precursor with hazardous solvents, and its safe reclamation. This study presents a solution by a solvent-free melt-spinning process with a copolymer produced from acrylonitrile (AN) with 1-vinylimidazole (VIM). A further significant improvement of the melt-spinning process is found with the additional use of a new oligomer as a plasticizer; the oligomer was prepared by polymerizing AN and methyl-2-(1H-imidazol-1-yl) acrylate (IA). The AN/VIM copolymer has glass transition temperature (T-g) of 115 degrees C but the plasticizer use lowers it to 75 degrees C. Thus, the oligomer plasticizer broadens the temperature range of melt-spinning processability. A carbon fiber prepared utilizing 8 wt% of the synthesized oligomer (Mn = 5 KDa) and high molecular weight base copolymer (Mn - 47 KDa), tensile strength of 1.9 GPa and modulus of 190 GPa have been achieved. (C) 2015 Elsevier Ltd. All rights reserved.</P>