• Journal of Biosystems Engineering
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• v.20 no.4
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• pp.390-396
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• 1995

This study was conducted to develop a computer simulation program for trickle application of nutrient solution. A computer simulation program using finite element method was developed to evaluate discharges of emitters on trickle application. The uniformity of application for two different lateral line lengths and three application methods was evaluated by the computer simulation program. The results of this study are as follows. 1. A computer simulation program was developed to determine emitter discharges from a trickle application system and pressures at emitter positions by finite element method and to design a uniform trickle application system. 2. The simulation program developed was verified by experiment. The root mean square error between experimental data and simulated data was 1.1% on the average discharge and it was found that the computer simulation program was an effective tool for the design of a trickle application system of nutrient solution. 3. The uniformity of trickle application system was evaluated for three different methods of supplying nutrient solution with different lateral line lengths. The best uniformity was obtained from the method, which supplies nutrient solution from both ends alternatively for the same period of time.

• Proceedings of the Korea Society for Simulation Conference
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• 1992.10a
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• pp.6-6
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• 1992

This work deals with nonlinear least squares method for estimating unknown universial constants C in a computer simulation code real experimental data(or database) and computer simulation data. The best linear unbiased predictor based on a spatial statistical model is fitted from the computer simulation data. Then nonlinear least squares estimation method is applied to the real data using the fitted prediction model(or simulation predictor) as if it were the true simulation model. An application to the computational nuclear fusion device is presented.

• Journal of Korean Society for Quality Management
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• v.12 no.1
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• pp.17-30
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• 1984

A computer method is developed for group technology layout and its simulation analysis. The method is composed of three phases: Phase I sorts the parts by its similar production routes and forms part families. Phase II plots the layout by machine cell and evaluates the group layout alternatives by the total process time analysis and the part travel distance evaluation analysis. Phase III also evaluates the alternatives by simulation analysis using SIMAN simulation software. All the computer programs are developed with BASIC except SIMAN simulation.

• International Journal of Quality Innovation
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• v.8 no.2
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• pp.100-114
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• 2007

Decision makers in the service industry must effectively cope with queuing problems, service capacity optimization, service efficiency and service quality problems. This study proposes a computer simulation-enabled MCDM framework that integrates computer simulation analysis, Taguchi method, expert opinion and multiple criteria decision making (MCDM) to assist decision makers in coping with decision problems. In this framework, Taguchi method is adopted to reduce the time required for the simulation experiment. Computer simulation analysis is adopted to obtain useful information for rapid decision-making without interrupting actual production. MCDM is used to select the optimal alternative. The illustrative result is extremely promising.

• International Journal of CAD/CAM
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• v.2 no.1
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• pp.39-44
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• 2002

This paper presents a structure and architecture of an integrated simulation method (ISM) to meet the requirements of virtual factory engineering (VFE). Combining CAD, VR and discrete event simulation techniques, the ISM provides static and dynamic simulation functions for implementation of VFE throughout the lifecycle. The static simulation can be used to evaluate the factory layout. The dynamic simulation enables us to evaluate ergonomics of factory, process performance of production system, feasibility of production plan and operation of factory, and to train operators safely, which cover the whole VFE lifecycle. The principles of the key techniques of VFE, including virtual factory data management system (VFDMS), static and dynamic simulation, are also discussed. To demonstrate and validate the ISM, a case study has been carried out in an assembly factory.

• Journal of Mechanical Science and Technology
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• v.19 no.spc1
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• pp.395-402
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• 2005

This paper deals with modeling and computer simulation of a full multibody vehicle model for a driving simulator. The multibody vehicle model is based on the recursive formulation and a corresponding simulation code is generated automatically from AUTOCODE, which is a symbolic computation package developed by the authors using MAPLE. The paper describes a procedure for automatically generating a highly efficient simulation code for the full vehicle model, while incorporating realistically modeled components. The following issues have been accounted for in the procedure, including software design for representing a mechanical system in symbolic form as a set of computer data objects, a multibody formulation for systems with various types of connections between bodies, automatic manipulation of symbolic expressions in the multibody formulation, interface design for allowing users to describe unconventional force-and torque-producing components, and a method for accommodating external computer subroutines that may have already been developed. The effectiveness and efficiency of the proposed method have been demonstrated by the simulation code developed and implemented for driving simulation.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.136-140
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• 2001

The 3rd generation mobile telecommunication fields are being standardized and developed in two parts, 3GPP and 3GPP2. These two parts have established each Network Architecture Models to achieve the goals basically required in the 3rd generation and to make it progress to IP network in the future. To achieve these goals many system architectures are proposed. Not only functional aspects but also performance aspects are considered as major factors. This paper proposes a new method of performance evaluation modeling and simulation that improved the existing way. The method proposed in this paper is Aspect oriented logical performance analysis Modeling and Simulation method. This proposed method is expected to improve efficiency of performance analysis modeling and simulation on the 3rd generation mobile telecommunication system.

• Journal of Korea Game Society
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• v.2 no.2
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• pp.46-51
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• 2002

In this study, a real-time simulation method for the phenomena, which are too complex to be simulated during real-time computer games, was proposed based on the neural network. The procedure of proposed method is to 1) obtain correlation data between input parameters and output parameters by mathematical modeling, code analyses, and so on, 2) train the neural network with the correlation data, 3) and insert the trained neural network in a game program as a simulation module. For the case that the number of the input and output parameters is too high to be analyzed, a method was proposed to omit parameters of little importance. The method was successfully applied to severe accidents of nuclear power plants, reflecting that the method was very effective in real time simulation of complex phenomena.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.1
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• pp.51-62
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• 2008

This paper proposes a second-order implicit constraint enforcement method which yields enhanced controllability compared to a first-order implicit constraints enforcement method. Although the proposed method requires solving a linear system twice, it yields superior accuracy from the constraints error perspective and guarantees the precise and natural movement of objects, in contrast to the first-order method. Thus, the proposed method is the most suitable for exact prediction simulations. This paper describes the numerical formulation of second-order implicit constraints enforcement. To prove its superiority, the proposed method is compared with the firstorder method using a simple two-link simulation. In this paper, there is a reasonable discussion about the comparison of constraints error and the analysis of dynamic behavior using kinetic energy and potential energy.

• Journal of the Korea Society for Simulation
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• v.2 no.1
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• pp.125-133
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• 1993

A statistical method is described for estimation of the unknown constants in a theory using both of the computer simulation data and the real experimental data, The best linear unbiased predictor based on a spatial linear model is fitted from the computer simulation data alone. Then nonlinear least squares estimation method is applied to the real experimental data using the fitted prediction model as if it were the true simulation model. An application to the computational nuclear fusion devices is presented, where the nonlinear least squares estimates of four transport coefficients of the theoretical nuclear fusion model are obtained.