Issue N^{o} 2, 1984 
ON AN APPROXIMATION OF THE RADIATION TRANSFER EQUATION
Yu. A. Dementyev, Yu. I. Ruzu, I. D. Sofronov, E. N. Tikhomirova VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 35.
A set of singlepoint algebraic equations is reported, fitting equlibrium nonstationary radiation transfer taking into account greymatter absorption and isotropic scattering. A cubic octahedron mesh is used. The scheme is conservative, stable, and, mainly, secondorder accurate. The approximate solution is characterized by nonincreasing amplitude. An arrayprocessor computer may be effectively used. A disadvantage of the scheme cons its in severe timestep 1imi tat ions.

A "MAJORAZING CROSSSECTION" METHOD FOR SIMULATING NEUTRON PASSAGE IN MOVING MEDIUM V. N. Ogibin, A. I. Orlov VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 69.
A "majorating crosssection" approach is proposed for solving a transfer equation with MonteCarlo method. Variants of the approach and associated algorithms of simulating neutron trajectories are considered.

BESM6 COMPUTER CHANNEL FOR MAGNETIC TAPES OF VARIOUS FORMATS V. I. Igrunov, L. N. Simagin VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 1013.
Possibility of using the BESM6 computer with a tape drive is considered without employing fast directions. The scheme of the channel is provided allowing information exchange between BESM6 and other types of computers (ES, MINSK32, ets.) with aid of MT. While exchanging via this channel the BESM6 runs only under a channel control routine.

IZOT1370 DISC DRIVE OPERATION EXPERIENCE A. D. Pantyushin, P. M. Rannev, Yu. I. Samsonov VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 1416.
Some questions concerning IZOT1370 (SM5400) exchangeable disk drive operation are considered. In particular, we propose variants of replacing failed components which have no domestic analogues. Efforts to achieve disc drive interexchangeability are discussed.

A MODEL AND A METHOD OF NUMERICAL SOLUTION OF TURBULENT MIXING OF ACCELERATING INTERFACE V. E. Neuvazhayev, V. G. Yakovlev VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 1725.
A semiempirical model of gravitational mixing is considered with eguation for turbulent kinetic energy. The model includes three constants. Model properties are investigated on selfsimilar solution for incompressible fluids. Linear dependence of mixing effective width on Atwood number is ascertained. A finitedifference method of solution of equations is given for general, nonselfsimilar case. A solution is derived for compressible gases with mixing for an automodel problem with two energy release regions.

A NUMERICAL SOLUTION TECHNIQUE FOR 3D NONSTATIONARY PROBLEMS OF ENERGY TRANSFER BY RADIATION THROUGH VACUUM REGION Yu. A. Dementyev, R. F. Mashinin, V. I. Nagorny, V. G. Rogachov, E. N. Tikhomirova VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 2628.
An integral equation is solved describing nonsta tionary energy transfer by radiation through a region of negligible optical width, retardation and shading being taken into account. A numerical solution technique is qiven based on mesh description of the process. Energy portions are calculated the computational cells exchange with on the radiating surface each time step. Examples of model calculations are supplied.

INTERPOLATION EQUATION OF STATE IN EVAPORATING REGION A. T. Sapozhnikov, A. V. Pershina VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 2933.
Computationallyeconomic interpolation equation of state is proposed for the energy range 0, ~200kj/g and density range ~10^{3}, 1,5ρ_{ok}, where is pressure at S.C. The economy is due to piecewiseanalytical representation form of the equation ef state and to using only polinomial and fractionaryrational functions in computational formulas. An approach to select optimal parameters of the equation of state is discussed and their values are given for aluminium, copper, and lead. Thermal characteristics calculated by the equation of state are compared with experimental data shock compression, thermal expansion, and evaporation.

LOM(I) ROUTINE FOR 2D CALCULATIONS FOR EVALUATING CRITICAL PARAMETER λ A. V. Nikiforova, V. A. Shumilin VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 3436.
Mathematical propositions, general organization, and capabilities of LOM(I) routine intended for evaluating 2D critical parameter λ in multigroup isotropic approximation are given. The routine is written for ES1060 Computer in PL1 language. The paper also contains calculations for axisymmetric λ systems and comparison of them with other results.

SOFTWARE DEVELOPMENT FOR REMOTE I/O TERMINAL THE BASIS OF ES8504 USER POINT V. A. Barannikov, A. A. Kibkalo, N. M. Mikiychuk, S. A. Firsov VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 3740.
The paper gives a brief description of ES8504 user point software (AP4), consisting of cross  system for AP4 running on the base of BESM6 computer, providing a full working cycle for creating and debugging routines for AP4 on BESM6, and of operating system AP4 permitting to use the point in job teleprocessing system as a remote input  output package node.

ON A MODEL PROBLEM OF NONEQUILIBRIUM RADIATION AND GAS INTERACTION V. A. Zhmaylo, A. A. Sadovoy, N. M. Chulkov VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 4146.
Solution of a model problem of cooling gas, which fills up a halfspace, due to heat transfer by nonequilibrium radiation is expressed in quadratures. Conditions are analysed concerning transition to equilibrium cooling mode described by heat  transfer equation.

IRMA: A FACTOGRAPHIC SYSTEM OF INFORMATION RETRIEVAL FOR REACTOR MATERIAL TESTING A. V. Rudkevich, V. G. Dvoretsky, V. B. Ivanov, B. A. Kanashov, Yu. V. Markov, V. M. Rayetsky, T. A. Temnoyeva VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 4756.
Basic architecture principles are given for information system providing prompt access to facts describing experimental conditions and results of reactor material testing. An approach is proposed for modelling a material field; methods of receiving answers to requests and software for usersystem dialogue organization are described.

KNOWLEDGE REPRESENTATION AND DATA CONTROL IN A FACTOGRAPHIC SYSTEM OF INFORMATION RETRIEVAL OF REACTOR MATERIAL TESTING IRMA A. V. Ruddkevich, T. A. Temnoyeva, Yu. V. Markov VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 5765.
A way of knowledge representation in a factograhic system of information retrieval is presented based on using semantic networks, indefinite values, and so called modal functions. On the basis of the suggested approach complex objects vehavior in time is simulated, deductive derivation is given, conclusions are made concerning ability of realization of varions combinations of facts. A way of knowledge representation is described using semirelational data base which relations are presented by disordered flat files. Time of answer retrieval for request is analysed and recomendations for its optimization are given.

INFORMATION "COMPRESSING" WITH NONUNIFORM NORM CODES S. A. Stepanenko VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 6671.
A class of nonuniform codes is proposed for information "compressing allowing minimization of coding and decoding algorithm complexities. Estimates of decoding algor thm cemolexities are obtained, in the capacity of which logic algorithms are used.

STABLE DIFFERENCE SCHEME FOR SOLVING HEAT CONDUCTION EQUATION BY REGION RUNS K. N. Baryshnikova, V. V. Zmushko VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 7275.
An algorithm of solving heat conduction equation is considered for separate regions. An inconditionally stable, economic difference scheme is constructed on the basis of run method. The maximum principle of flow is proved. The scheme may be applied to solve diffusion problems, especially twodimensional ones with complex geometry.

ON THE PROBLEM OF CAUSAL ELECTROMAGNETIC DISTURBANCE SPREAD N. Yu. Bakayev VANT. Ser. Metodiki i Programmy Chislennogo Resheniya Zadach Matematicheskoy Fiziki. 1984. No 2. P. 7679.
A convenient form of solution of direct problem of electromagnetic disturbance spread in homogeneous conducting media is considered for the class of causal pulses.

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