Согласно отчету Межведомственной комиссии по развитию сверхмощных вычислений США, эффективность современных параллельных систем находится ниже отметки в 10 %. Для того, чтобы добиться приемлемой эффективности, разработчики пользуются инструментами поиска и устранения проблем производительности. Большая часть таких инструментов полагаются на пользователя при анализе и интерпретации данных, но есть ряд систем позволяющих в той или иной мере автоматизировать этот процесс и снизить нагрузку на пользователя. В статье приведен краткий обзор таких инструментов и методов. According to the report of the USA High-end computing revitalization task force (HECRTF) sustained performance of contemporary parallel machines is less than 10 %. To gain acceptable parallel performance programmers often use performance analysis instruments. Most of them entirely rely on developer in finding parallel performance problems but some automate this process more or less. This paper is dedicated to such kind of instruments.
In conditions of constantly increasing demand on computing resources from natural, social and other sciences need of qualitative and easy-to-use software for performing computations on these resources in data centers also increases. Computing clusters, which contain many nodes, each of which has its own operating memory, are the most popular architectural solutions for high performance systems today. MPI (Message Passing Interface) is a de-facto standard for programming computing clusters. MPI is very complex and requests managing of data transmitions between nodes in low level from programmer. Debugging of MPI applications is very hard process, because of new errors appearing from undeterministic behavior of independent processes. That is why applying special instrumental systems is essential for parallel debugging. So classification of errors in parallel applications and analysis of methods and existing debugging systems for these applications are extremely actual and important tasks nowdays.
Eigen frequencies problem of a circular cylindrical multilayered composite shell loading external static axial symmetry pressure is investigated.
The present work is devote to development of numerical algorithms bases on natural element method for solving of hydrodynamics problems with free boundaries.
SOR method is used for solution of system linear algebraic equations successfully (SLAE). Cause: both simplicity of realization and high rate of convergence in case of precise assignment of optimal iteration parameter. Using of nonoptimal parameter appreciably decrease rate of convergence of SOR method.
Iteration methods of solution of SLAE and system bilinear algebraic equations (SBAE) have been considered in this paper. These methods are SOR in linear case and - successive over and block relaxation method in nonlinear case. Constant iteration parameter is replaced by diagonal matrix of parameters in these iteration schemes.
In the work the class of dynamic matrix games described by the difference equations, along trajectory of which the payoff matrix of players is set, is defined. New concepts of strategy, saddle point and game price are introduced. The necessary and sufficient condition of optimality of strategy is found.
The work considers analysis of reflection disturbance in nonuniform multiwire transmission lines in the time domain. The analysis is carried out using the TVD-scheme of the Godunov method. The results of numerical simulation are compared with other authors' results and the experiment. The results of numerical simulation are represented as diagrams for the signal and passive lines.
The work is devoted to the building of the mathematical model of sustainable development of region based on the global model World 3 and to the formalization of its major factors taking into consideration the theoretical preconditions. Necessary and sufficient optimality condition for the built model is proved, method of calculation of optimal trajectories is given.
This article devoted by research children's idea about family. Children's associations and personal constructs ( the basic meaning categories) are described in this part of experience.
In article results of studying of responsibility of person of students are stated. Results of the short theoretical analysis of responsibility of the person are adduced. Results of experiment by definition of a level of responsibility and its connection with social conditions of residing of students of university are considered.
In the presented work health of the person and its communication with a level of impellent activity is analyzed. It is shown, that only optimum impellent activity gives improving effect. This effect is reached, when physical activity is physiologically proved and corresponds to physiological opportunities of the individual. Hypocinesia reduces the general energy potential of an organism and its stability to factors of an environment.
This article presents a panorama of cultural life, literature and language of russian «white» emigres in a wide context.
The author suggests her analysis of collected material with the aim of discovering compositional models in school written note dependent on status and role characteristics of communicants. The structure of communicative situation in school is also considered.
The article deals with the problems related to natural written speech. The paper is an attempt to reveal integral and differential characteristics which enable to consider marginal pages of copybooks as a specific genre of natural written speech. The paper defines the genre status of marginal pages of copybooks and separates various aspects of their investigation.
The article deals with the description of concepts life and death in rock-texts. The value level of the given concepts are pointed out. The author describes the ideologems, forming value dominants of rock-culture.
The article is devoted to a general review of Russian intellectuals who wrote about peculiarities of American and Russian mentality, about perspectives of global social development and about issues of cultural wealth. The author dwelt on the most important thinkers of fours waves of Russian emigration in America. The contributor defines main specific traits of every wave and exemplifies its typical representatives.
Nanoparticles and silver layers have been obtained from the solution by restoration method as well as thermal coating one. Nanoparticles and silver layers have been studied by photometry and x-rayed electron microscopy methods. The spectra of optic adsorption and passing have been analyzed in the framework of Mie theory and the theory of plasma resonance oscillation values: Ne - effective concentration of electron conductivity, γ - attenuation coefficient of plasma oscillations, NV - values of the bulk amount of nanoparticles in the unit volume of the system have been calculated. Values λmax - wave lengths in adsorption maximum and passing of plasma resonance strips have been received from the spectra of optic adsorption and passing. Phase constitution and morphology of silver particles have been investigated by X-rayed electron microscopy method.
In this article the specificity of account receivable of natural persons against the municipal and state unitary enterprises of housing and communal services in the conditions of competitive production is considered. Analysis indicators of account receivable, methods and approaches of market value definition are characterised.
It's considered mathematical statement and the decision of the problem of minimization of expenses for resources by manufacture of some kind of the goods with restriction in the form of production function of the several variables, expressing limitation of demand for the given goods.
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