Statistical Simulation Method Research Articles

Muon production and transport in matter in the energy range 10 1 − 10 5 GeV

This paper investigates the role of the muon production mechanism and that of fluctuations of the energy losses and angular deviations in matter due to 10 1 − 10 5 GeV muon interactions. The method of statistical simulation, as it is realized in the MUTRAN programme, is developed. When considering physical processes the corresponding simulation algorithms are described. Some regularities of muonic field production in big accelerators are presented.

Development and application of the method of numerical statistical simulation for the solution of multidimensional problems of the theory of radiation transfer

Development and application of the method of numerical statistical simulation for the solution of multidimensional problems of the theory of radiation transfer

Digital Transmission Over Existing Subscriber Cable

The paper first describes strategies to permit the smooth transition to all-digital operation in the subscribers' area. This emphasizes the essential employment of the existing network to support alldigital working. Two particular aspects of the many factors relevant to such realization are then highlighted-signaling and transmission. It is claimed that the former must provide a rich signaling repertoire, but that such a system may demand international agreement. An outline of a possible solution is given. The transmission capabilities of the existing subscribers' area network are discussed, with particular reference to limitation by near-end crosstalk, and the results of swept-frequency measurements of typical cable crosstalk characteristics are analyzed. An outline of the statistical simulation method of interference summation used to combine these results with differing digital system parameters is described. It is concluded that, with suitable line codes and stackable systems, the existing network will normally support all-digital working.

Transient state isoelectric focusing: Computational procedures for digital data processing with a desk-top programmable calculator

Computational procedures (applicable to desk-top programmable calculators) have been described which are useful in the processing of data generated by transient state isoelectric focusing (TRANSIF) experiments. The system allows the calculation of methological parameters such as peak position, peak separation, segmental pH gradient, resolving power, and resolution. “Apparent” physical constants such as the isoelectric point ( pI), diffusion coefficient ( D), and the slope of the pH-mobility curve ( du d ( pH) ) of amphoteric molecules can be calculated either by linear interpolation ( pI) or by linear regression analysis ( D and du d ( pH) ). The computing programs are also capable of performing operations such as smoothing of raw data, conversion to absorbance, baseline detection and correction, and calculation of the higher statistical moments of Gaussian, bi-Gaussian, and asymmetric peak shapes. Moment analysis is carried out by direct statistical procedures, curve simulation, and slope detection methods. The above computational procedures provide a useful and necessary adjunct to the scanning isoelectric focusing assembly which is coupled to a digital data acquisition and recording system.

Solution of the inverse secular problem by “Monte Carlo” method

Abstract The method of statistical simulation (Monte Carlo) has been applied to obtain a complete solution of the inverse secular problem in a chosen (fixed) domain. The method is illustrated by calculations of the NMR parameters for the vinyl protons in acrylonitrile and of the Urey-Bradley force field for the isotopic molecules of 14 NOCl and 15 NOCl.

Medical system engineering

Medical system engineering is a theoretical discipline which unifies the methods of analysis and synthesis of complex medical systems, medical technology, and public health services in general. The work of medical institutions typically involves an abundance of medical and economic information, basically in statistical form. Mathematical models of medical institutions establish regularities in the mass of empirical information and remove distortions in the statistical data, thereby aiding the work of planning organizations. Considering medical institutions as complex queueing systems involving cost estimates of the institutions themselves and implicit losses connected with delay times, gives a theoretical basis for choosing the parameters of the medical institutions to be economically optimal. To determine these parameters we must solve problems of nonlinear programming. Some particular problems of public health services are studied: i.e., determining the optimal number of beds in a hospital and the optimal number of ambulances, and determining periodicities in conducting prophylactic examinations. The study of the systems of several medical institutions and their influence on the flow of patients leads to the use of the method of statistical simulation. A simulation using the Markov process, changing the random waiting times of individual cases to their mean values, thereby decreasing the variance of the statistical estimates, is considered. A numerical example is given, illustrating one heuristic approach to estimating the accuracy of the results of this type of simulation. The contradiction between the level of scientific achievements of medicine and the possibilities of their wide practical realization is discussed in the framework of the present system of public health services where individual forms of labor prevail, hampering the effective use of medical technology. The importance of computer automation in processing medical information is pointed out.

A competitive adsorption model of steady-state growth of a crystal from a lightly-doped melt

The molecular dynamics (MD) simulation technique has been employed to investigate the thermodynamic properties and transport coefficients of the neat liquid dimethyl sulfoxide (DMSO). The fluid has been studied at temperatures in the range 298–353 K and at a pressure equal to 1 atm. The simulations employed a nine-site potential model, which is presented for the first time here, and all the available non-polarizable models. The performance of each model is tested using the same statistical mechanical ensemble and simulation method under the same conditions, revealing its weaknesses and strengths. Thermodynamic properties, microscopic structure and dynamic properties, such as transport coefficients, rotational and single-dipole correlation times have been calculated and compared with available experimental results. Estimations of transport coefficients from various theoretical and empirical models are tested against experimental and MD results. Translational and rotational dynamics suggest the existence of the cage effect and agree with the Stokes–Einstein–Debye relation. The dipole relaxation times calculated are discussed in terms of simple and useful approximations, such as the Glarum–Powles and Fatuzzo–Mason models.