Program for computer simulation on photoproduction of mesons decaying into two photons

Developability assessment of clinical drug products with maximum absorbable doses

The authors sought to verify computer simulation of visual fields by comparing thresholds of real and corresponding simulated visual fields. Four patients with stable glaucomatous visual fields and three patients with progressing glaucomatous visual fields were chosen for the study. Visual fields had been recorded at 6-month intervals for 5 to 7.5 years. A previously described computer simulation program was used to generate a corresponding simulated visual field for each of the real fields. Twenty different levels of response variability and long-term variability were used in the simulations. Pointwise sensitivity differences between real and simulated fields were calculated. The average difference and 95% interval of the differences were analyzed for the different simulation conditions, for the pointwise sensitivities in the real patient fields, and to determine whether the field was stable or progressing. In almost all simulation conditions, the average pointwise sensitivity differences ranged from -1 to 1 dB and were not significantly different among different simulation conditions. The 95% interval of the average difference increased significantly with response variability, whereas long-term variability failed to show any apparent effect. Average pointwise differences and the 95% intervals were greatest in locations where the real-patient field had reduced sensitivity of 14 dB or worse. The simulation program provided good estimates of visual field sensitivities. Increasing amounts of response, but not long-term variability, produced a linear increase in the variability of threshold sensitivities. This finding implies that short-term rather than long-term fluctuation is the most important factor determining the variability of thresholds.

This paper describes the problems, mainly from a standpoint of circuit stability, in the case in which we analyze and design analogue integrated circuits using a computer simulation program. Although a fundamental condition of an analogue circuit is whether DC bias can be determined stably or not, computer simulation is not good at this stability check and it is pointed out that an unstable circuit is sometimes checked to be stable accidentally. In the circuit partitioning process used in large‐scale integrated circuits, a risk that is shown in examples is that, depending on the manner of partition, its subcircuit may become unstable and it makes analysis of the whole circuit impossible. As an example we take SPICE, a representative program for analogue circuit simulation, to discuss the problem of default values in the program, direct current bias analysis, one that inside of a computer is assumed to be ideal, and the necessity of transient analysis. Then it clarifies the importance of correct modeling of circuit elements and careful usage of a simulation program after good understanding of its properties.

Analytical theory of low and medium energy ion reflection by target surface atoms during sputtering

Why use computer simulation as an educational tool? Why is computer simulation based on mathematical models? What kinds of computer simulations are there? What is the difference between computer simulation and modeling? What is the difference between a model and a program? What are some advantages and disadvantages of computer simulation programs? What is the difference between learning through discovery and various kinds of coached learning? In which five ways can computer simulation programs be used?

Computer simulation and virtual computer experiments are one way of introducing students to concepts without the high cost of traditional experimental equipment. Computer simulation can show students the effectsof room reverberation on different types of acoustic signals including speech and music and to show the noise control effects of absorptive materials. Computer based digital filters can be used with audio files to auralize the acoustic transmission loss of different materials and constructions. In this presentation the use of computers for simulation and virtual experiments in architectural acoustics is discussed. A variety of modern computer programs for acoustic prediction and simulation of room acoustics and noise control are reviewed.

This work deals with the investigation of the effect of a more recent, powerful control algorithm, called Pseudo Derivative Feedback, PDF, on the performance of a hydraulic servomechanism. The controlled system behavior is theoretically evaluated by developing a mathematical model for the controlled system and by using a computer simulation program. Also, the experimental measurement of the system dynamic performance is conducted. The developed simulation program is validated by comparing theoretical and experimental results of the system response. The simulation program is used to deduce a transfer function for the studied servomechanism. Once the transfer function of the controlled system is obtained, the control algorithm implementation is performed. To define the advantages of the proposed control algorithm, its output is compared to that of the already existing unity feedback system. Finally, A proposal for the design of the PDF controller is presented.

A computer simulation program for evaluation of the continuous heat treatment of particulate food products. Part 1: Design

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Computer simulation techniques have become an essential tool for scientists and engineers in various areas including food processing. Cake baking is a very complex process that brings about a series of physical, chemical and biochemical changes within a product that are influenced by conditions in ovens. The objective of this study was to develop a computer simulation program for cake baking in a continuous industrial oven, which can be used to predict the transient and spatial temperature and moisture distributions inside the product, and the dynamic volume expansion of cakes under continuous oven conditions observed in multi-zones industrial ovens. A finite difference method was implemented to solve the thermal and mass transfer differential governing equations. The Kelvin model was used to describe the cake volume expansion considering a balance of driving forces and resistances. Variable zone temperature and moisture profiles and variable thermo-physical properties as a function of temperature and moisture were used. A set of experimental results of cake temperature and moisture under different processing conditions was used to compare with those obtained from various computer simulations. Statistical results showed that correlation coefficients for the relationship between predicted and experimental results were R2=0.96 for temperature and R2=0.92 for moisture. Several computer simulations were further used for a sensitivity analysis of main processing conditions on the development of the final cake volume. It can be expected that this computer simulation program will become a useful tool for the cake baking industry to search for optimal processing conditions to improve cake quality while saving energy.

SAFSIM (System Analysis Flow SIMulator) is a FORTRAN computer program for simulating the integrated performance of complex flow systems. SAFSIM provides sufficient versatility to allow the engineering simulation of almost any system, from a backyard sprinkler system to a clustered nuclear reactor propulsion system. In addition to versatility, speed and robustness are primary SAFSIM development goals. SAFSIM contains three basic physics modules: (1) a fluid mechanics module with flow network capability; (2) a structure heat transfer module with multiple convection and radiation exchange surface capability; and (3) a point reactor dynamics module with reactivity feedback and decay heat capability. Any or all of the physics modules can be implemented, as the problem dictates. SAFSIM can be used for compressible and incompressible, single-phase, multicomponent flow systems. Both the fluid mechanics and structure heat transfer modules employ a one-dimensional finite element modeling approach. This document contains a description of the theory incorporated in SAFSIM, including the governing equations, the numerical methods, and the overall system solution strategies.

A randomized control trial comparing use of a novel electrocardiogram simulator with traditional teaching in the acquisition of electrocardiogram interpretation skill

Development of a numerical method for the performance analysis of thermoelectric generators with thermal and electric contact resistance

Onchocerciasis control strategies

SUMMARY 1. Zooplankton production in a eutrophic reservoir was estimated by three common methods.2. Estimates of daily production from the growth increment method and the birth and death rate versions of the biomass turnover method were poorly correlated (r=0.58–0.60). Estimates of daily production rates from the above two versions of the biomass turnover method were strongly correlated (r=0.90).3. The mortality rate version of the biomass turnover method is illogical and yields anomalous results.4. The growth increment method assumes steady state conditions and zero deaths within each stage and hence calculates potential production for each stage.5. Estimates from a new computer simulation (PROD) were strongly correlated with (r=0.92) but lower than those from the growth increment method. Estimates from PROD were more poorly correlated (r=0.78) with those from the biomass turnover method.6. There is a strong need for improved methods for estimating secondary production; computer based methods would seem to be the most promising.