• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.5 no.1
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• pp.51-57
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• 1996

Although the system for establishing grinding operation standards mainly depends on the simulation method, it is desirable to obtain highly reliable grinding data and to develop experimental technology, And, it also needs to modify the simulation models if the simulation results do not coincide with special situation due to the difference of grinding machine, wheels and workpiece materials. If simple tests are carried out to evaluate these specificity, the reliability and utility of the system can be raised higher. Therefore, it is required for evaluating wheel ability and confirming the validity of the experimental methods as well as the possibility of exchanging the experimental data between Korea and Japan to preform several kinds of grinding experiments. In this paper, experiments of cylindrical plunge grinding were conducted using the wheels of the same specification made by three typical grinding wheel manufacturers both in Korea and Japan, respectively. The grinding power consumption grinding force, the ground surface roughness, and wheel wear were measured under the same dressing the grinding conditions. The average value and standard deviation of the experiment results were calculated to compared the grinding performance of the wheels made in both countries. The experiment results show that the grinding wheel performance of Korea's is nearly equal to that of Japan's for general purpose of grinding operation. In conclusion, it is possible to exchange the experimental data between Korea and japan.

• Wind and Structures
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• v.1 no.4
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• pp.337-349
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• 1998

A numerical and experimental study was performed for the wind flow field in one area, comprising a group of several pavilions separated by passageways, of the EXPO '98 - a World Exposition (Lisbon, Portugal). The focus of this study is the characterization of the flow field to assess pedestrian comfort. The predictions were obtained employing the Reynolds averaged Navier-Stokes equations with the turbulence effects dealt with the ${\kappa}-{\varepsilon}$ RNG model. The discretization of the differential equations was accomplished with the control volume formulation in a Cartesian coordinate system, and an advanced segregated procedure was used to achieve the link between continuity and momentum equations. The evaluation of the overall numerical model was performed by comparing its predictions against experimental data for a square cylinder placed in a channel. The predicted values, for the practical geometry studied, are in a good agreement with the experimental data, showing the performance and the reliability of the ${\kappa}-{\varepsilon}$ RNG model and suggesting that the numerical simulation is a reliable methodology to provide the required information.

• Nuclear Engineering and Technology
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• v.50 no.3
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• pp.439-445
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• 2018

Experimental measurements of the response of $BF_3$ detector to a 3 Ci Am-Be neutron source for three different reflecting materials, i.e., aluminum, wood, and Perspex of varying thicknesses have been carried out. The varying contribution of wall effect to the response due to change in active volume of the detector has also been determined experimentally. Then, a Monte Carlo code has been developed for the calculation of the neutron response function of the $BF_3$ detector using source biasing and importance sampling. This code simulates the $BF_3$ detector response exposed to the neutron field in a three-dimensional source, detector, and reflecting medium configurations. The results of simulation have been compared with the corresponding experimental measurements and are found to be in good agreement. The experimental neutron albedo measurements for various values of Perspex thickness show saturating behavior, and results agree very well with the data obtained by Monte Carlo simulation.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2852-2859
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• 2020

This paper deals with the simulation-based design optimization and experimental validation of the characteristics of an in-core silver Self-Powered Neutron Detector (SPND). Optimized dimensions of the SPND are determined by combining Monte Carlo simulations and analytical methods. As a first step, the Monte Carlo transport code MCNPX is used to follow the trajectory and fate of the neutrons emitted from an external source. This simulation is able to seamlessly integrate various phenomena, including neutron slowing-down and shielding effects. Then, the expected number of beta particles and their energy spectrum following a neutron capture reaction in the silver emitter are fetched from the TENDEL database using the JANIS software interface and integrated with the data from the first step to yield the origin and spectrum of the source electrons. Eventually, the MCNPX transport code is used for the Monte Carlo calculation of the ballistic current of beta particles in the various regions of the SPND. Then, the output current and the maximum insulator thickness to avoid breakdown are determined. The optimum design of the SPND is then manufactured and experimental tests are conducted. The calculated design parameters of this detector have been found in good agreement with the obtained experimental results.

• Computers and Concrete
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• v.34 no.2
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• pp.169-178
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• 2024

To circumvent the constraints of time-consuming experimental methods, numerical simulation can be one of the most effective approaches to investigating chloride diffusion behaviors in concrete. However, except for the effect of the external environments, the transport direction of the chloride cannot be neglected when the concrete is exposed to the marine tidal zone, especially in certain areas of concrete members. In this study, based on Fick's second law, considering the effects of timevarying, chloride binding capacity, concrete stress state, ambient temperature, and relative humidity on chloride diffusion coefficient, the modified one-dimensional, two-dimensional, and three-dimensional novel modified chloride diffusion theoretical models were established through defining the current boundary conditions. The simulated results based on the novel modified multi-dimensional model were compared with the experimental results obtained from some previous pieces of literature. The comparing results showed that the modified multi-dimensional model was well-fitted with experimental data, confirming the high accuracy of the novel modified model. The experimental results in literature showed that the chloride diffusion in the corner area of the concrete structure cannot be simulated by a simple one-dimensional diffusion model, where it is necessary to select a suitable multi-dimensional chloride diffusion model for simulation calculation. Therefore, the novel modified multi-dimensional model established in this study has a stronger applicability for practical engineering.

• 한국기계연구소 소보
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• s.17
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• pp.111-123
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• 1987

Two dimensional computer simulation of solidification behavior using FDM as simulation tool was applied to AI-bronze casting. By the comparison of computer simulation with the experimental results, it was showed that the final shrinkage position and solidification time are good accordance with results of computer simulation. It is expected that this software will be widely applied to casting design or rise ring for directional solidification.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.34
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• pp.115-121
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• 1995

The objective of this study is to develope an effectiveness measurement technique for U-shaped JIT production line by computer simulation. A small and medium sized automobile brake master cylinder manufacturing plant is studied for productivity improvement The production line is analysed and improved by applying Low Cost Automation, special jigs and fixtures, and facilities layout changes. An experimental simulation model is built using SIMAN(SIMulation ANalysis) simulation software for the production system analysis.

• Journal of the Korea Society for Simulation
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• v.9 no.4
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• pp.77-85
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• 2000

The object of this paper is developing of a simulation model for performance evaluation of ai defense-gun system. We developed a three-step kill probability of areal target in case of one gun on one target considering : 1) estimating the target and warhead intercept point, 2) target vulnerability and 3) computing the kill probability. We used a Monte Carlo simulation method. This model can be used for probabilistic analysis giving results of sufficient accuracy with minimum requirement of input data. Also we developed a computer program according proposed algorithm and a set of experimental results using the proposed method are shown.

• International Journal of Contents
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• v.17 no.3
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• pp.30-37
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• 2021

This study aimed to determine the effects of simulation learning program using SBAR (Situation, Background, Assessment, Recommendation) techniques on undergraduate nursing students' clinical judgment and communication skills. A quasi-experimental research design (one-group pretest-posttest design) was used in this study. The participants included 88 students from a nursing college. There were statistically significant differences in clinical judgment, communication clarity, and communication confidence between pre-simulation learning using SBAR and post (t=10.32, p<.0001; t=6.05, p=<.0001; t=7.42, p=<.0001). The simulation learning program using SBAR was found to improve nursing students' clinical judgment as well as clarity and confidence in interprofessional communication.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.1-8
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• 2018

In this study, a small-scale siphon breaker experimental facility was designed to examine the validity of the Siphon Breaker Simulation Program (SBSP). To design the experimental facility, the simulation results of the C factor, Chisholm B coefficient, and Undershooting Height (UH) were obtained by SBSP. The major parts of the experimental facility were the upper tank, lower tank, downcomer, and Siphon Breaker Line (SBL). The area of the Upper tank was $0.09-m^2$ with a height of 0.65-m. The height of the downcomer was 1.6-m. Pressure transmitters and an electronic scale were used to obtain the experimental results. The experimental variables were the sizes of Loss of Coolant Accident (LOCA) and SBL. The experimental results were analyzed by UH. The SBSP well predicted the UH with an error of 2.5%. Overall, it is possible to design siphon breakers with various scales using SBSP.