Issue N^{o} 1, 1989 
DDIAGRAMS: A GRAPHIC MEANS FOR DATA DESCRIPTION
V. N. Ogibin, V. H. Shmakov VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 38.
We propose a graphic means for complex structure data description. Data organization relies upon three structure types (fetch, direct product, sequence) and three nonstructure types (integer, real, string). For each type, a graphic image is found to match it. Two ways for data representation are examined along with data type definition: the first is to store, the second is to display or to print. Using Ddiagrams is exemplified by several real applications.

CONSTRUCTING AND OPTIMIZING 3D CURVILINEAR GRIDS Zh. M. Sakhabutdinov, G. A. Petrov, S. F. Waigurova VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 918.
We discuss a procedure for calculating curvilinear grids in simple and complex spatial regions. This is based on interpolating coordinate values of 3D region inner points over boundary surface nodes. Grid line smoothness and orthogonality and equal volumes in nearby cells are achieved by moving inner nodes depending on quality parameter values. 2 and 3D regions of various complexity are calculated.

INVESTIGATING PLASMA DENSITY PROFILE DEFORMATIONS DUE TO PONDEROMOTIVE FORCE UNDER NONSTATIONARY CONDITIONS S. G. Garanin, Yu. F. Kiryanov, G. G. Kochemasov VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 1923.
A numerical technique is developed to compute a plasma density profile deformation due to a pondero motive force of a highfrequency electromagnetic radiation under nonstationary conditions in one dimension. The chosen scheme is shown to describe, with a good accuracy (≤3%), available analytic results: MandelschtammBri1louin forced scattering from a homogeneous plasma layer, stationary solution of a density profile binding problem. Calculational results for density profile deformation are given which indicate the jump instability for pulses greater than 0,1 ns.

A MODIFICATION OF DS_{n}METHOD A MODIFICATION OF DS_{n}METHOD A MODIFICATION OF DS_{n}METHOD O. S. Shirokovskaya VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 2429.
A modification of the DS_{n}method is suggested to solve a transport equation numerically in a sphere geometry. Nonlinear correction is used to specify additional relationships/and quadratic formulae in terms of solution changes within a simple grid interval in a direction space. The modification proposed increases greatly the difference solution quality and removes a disadvatage of the DS_{n}method occurring when particle flows are transferred at great distances. The modification efficiency is confirmed by test calculations.

TECHNIQUE FOR SOLVING 3D TIMEDEPENDENT PROBLEMS IN GAS DYNAMICS USING LAGRANGE VARIABLES A. Yu. Artemiev, V. I. Delov, L. V. Dmitrieva VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 3039.
Integralinterpolation method is used for developing an explicit difference scheme to solve numerically 3D timedependent problems in gas dynamics. Discretizing differential equations, written in Cartesian coordinates, takes velocity values at semi  integral times as in the 1D CREST scheme. The resulting scheme, for smooth solution regions on uniform and orthogonal grids, has a secondorder time and space approximation and is stable when the Courant condition is met. For grids formed by flowisolines, the scheme retains the symmetry in three types of 1D flow: plane, cylindrical and spherical ones. Calculations performed on coarse grids indicate that the scheme has good conservative properties. The difference scheme performance is illustrated by three test problems.

LDSCHEME FOR A TRANSPORT EQUATION IN A SPHERE GEOMETRY E. V. Diyankova, O. S. Shirokovskaya VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 4043.
An LDscheme is developed for a transport equation in a sphere geometry, which is then studied numerically and compared to that of the DS_{n}method. The following advantages of the LDscheme are revealed: a possibility to reduce the number of cells in a phase space by a factor of 2 or more for each variable while retaining a good solution accuracy and to consider the scheme to be actually monotonous, since the solution oscillation amplitude is very small even on coarse grids of a phase space.

ON MINIMUMPHASE NATURE OF LONG HOMOGENEOUS COMMUNICATION LINES V. D. Lartsev, Yu. I. Chernukhin VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 4447.
We study an issue associated with a unique relationship between AFC and PFC in a homogeneous long communication lines. The approach we take to solve the problem is based on a causal relation between primary parameters of a communication line which was not used so far. We show that the transfer ratio in a real line may be represented in the form of two multipliers, one of them corresponding to a minimumphasetype circuit and the other relating to a nondistorting delay line of nonminimumphase type. Given the delay length, the relationship between AFC and PFC in a homogenegus line is established in a unique manner.

DETERMINING GROUP CONSTANTS AND ACCOUNTING SCATTERING ANISOTROPY V. М. Shmakov VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 4851.
An approach suggested for constant determination is to maintain a number of characteristics in a neutron flow which occurs after the interaction with a target neucleus when the scattering anisotropy is accurately or approximately described. The requirement that a number of associated harmonics in a resulting secondary flow, material breeding properties, energy release and intergroup transition matrix elements should be retained, gives formulae for a generalized transport approximation of scattering anisotropy. Restricting crosssection correction value leads to physically noncontradictory values for intergroup transition probabilities.

JOB INPUT SYSTEM FOR A COMPUTER COMPLEX А. А. Kibkalo VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 5255.
A job input system is generally described for a nonhomogeneous computer complex. The system implementation principles and functional structure are examined. Hightechnology level involved in the system operation is emphasized and its performance characteristics are given.

EXTERNAL CONNECTION MONITOR FOR SVS OS V. A. Barannikov, N. N. Vyskubenko, V. D. Trushchin VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 5659.
An external connection monitor, as an integral part of the SVS OS, is described which permits to run the SVS within a technological massivecomputation complex based on a nonhomogeneous computer facility. The SVS’s are connected to central ES computers through ES4061 channeltochanne1 adaptors. The SVS is incorporated into the nonhomogeneous computer facility as a peripherial (host) computer which receives tasks via a shared input system, executes them and transmits the results (output files) to a shared output system. The monitor functions and capabilities are described, its implementation principles are examined and some data, obtaned from the monitor operation experience, are given.

100200 MBYTES DISC PACK RECOVERY A. A. Erokhin VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 6063.
A procedure is given and an order of operations is established for 100200 MB disc pack repair, shown to be feasible, using simple tools available to any computer center.

A VARIABLE SEPARATION METHOD N. Yu. Bakaev VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 6467.
A representation s developed for a generalized abstract boundaryvalue problem solution which may be interpreted as a variable separtion method. The paper examines whether this representation is suitable for developing an efficient algorithm to solve a boundaryvalue problem for a partialderivative equation.

JOB COMPLEX MONITOR IN ES OS A. M. Gordienko, S. M. Zhdanov, E. F. Nemtsov VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 6870.
We examined a problem involved in managing algorithmconnected batch jobs in ES EVS OS. Monitor systems with similar functions are briefly reviewed. Interconnected job complexes are described in the hypergraph language. Job interconnectivity conditions are naturally defined by the edges of an oriented graph where the set of vertices matches that of jobs. Interconnected job complex execution is simulated by colouring this hypergraph. A specific algorithm is given. A "block” term is introduce to make large hypergraph compact, corresponding to that of "subgraph". It is possible to modify job contents with modification algorithms. The monitor operation does not result in main memory fragmentation and latency. An actual time required to execute complicated job sets is reduced in average by 20%.

SYNTAX ANALYZER DEVELOPMENT SYSTEM FOR LL(I)GRAMMARS V. A. Kubiak VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 7174.
The paper described the KOSA system which allows to automate the creation of control tables for a generalpurpose syntax analyzer that implements onepass parsing without returns. A language, close to the BNF, is suggested to describe the formal grammar. Genera 1purpose syntax analyzer and grammar coder programs are written using the SOP system. This makes them easy to move on other computers. The KOSA system permitted to develop analyzers performing faster than previously used.

QUARTZ EQUATIONOFSTATE COMPUTER MODEL V. F. Kuropatenko, I. S. Minaeva VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 7576.
A quartz equationofstate computer model is presented in a region of a and stishovite phase mixing. One of the reported equationsofstate is used to describe each phase properties. For the region of phase mixing, the functions incorporated into the equationofstate are defined to make the Hugoniot adiabat linear. Thus, a satisfactory experimental data description is obtained.

A METHOD FOR IMPLEMENTING PARALLEL COMPUTATIONS WITHIN THE DUBNA MONITORING SYSTEM RUN ON THE SVS COMPUTERS USING DISPAK OS BASE EXTRACODES V. M. Isaev, N. V. Shumilina VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 7677.
The note describes a method for implementing parallel computations on the SVS multicomputer running the TIGRF package designed to calculate 2D heat conducting gas flows in EulerianLagrangian coordinates. Parallel computations were made possible by DISPAK OS generic capabilities and a multiprocessor operation system developed for the SVS. 16 base extracodes are used to start parallel mode. Experimental and fullscale computations were performed in parallel mode giving a computation speedup ratio of 1.61.9 (for two processors).

CALCULATIONS OF A CANTILEVER BEAM MAXIMUM OSCILLATION AMPLITUDE V. R. Borkovsky VANT. Ser.: Mat. Mod. Fiz. Rroc.. 1989. No 1. P. 7879.
Three various ways are examined for deriving a formula used to compute the maximum oscillation amplitude of a prismatic cantilever beam which is needed when solving structure strength and stability problems. An exact formula value obtained using severe free oscillation is shown to differ by about 12% from approximate data resulted from applying beam oscillations in the from of a static deflection.

[ Back ] 