• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.343-345
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• 1998

By computer simulation, the pattern of magnetic field distribution on the Nb-foil of a rotating flux type superconducting power supply has been calculated. Using the results, the current pumping rate has been calculated and compared with the results obtained by the experiment. The experiment has been executed with small-size flux-rump in the environment of LN2 and LHe in order to compare the pattern of magnetic filed in the superconducting state and in the normal state. Five hall-sensor was located on the center, right side, left-side, upper side, lower side of the Nb-foil in order to obtain more accurate pattern of the magnetic field generated by rotating pole. In the simulation, the effects of the excitation-magnet and the iron core located at the inner-side and circumference of the magnet have been considered. By comparing the data from the experiment and the results from the simulation, the size of normal spot estimated. At the same time, by calculating the linkage flux, the current-pumping-rate has been obtained. Consequently, the results obtained from experiment and simulation coincided as expected.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.451-456
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• 2007

A finite element analysis and experiment study of a motorcycle helmet are presented in this paper. The finite element LS-DYNA3D code is used to analyze the helmet. The test specimen, instruments, and setup procedures are described. Since the displacements and Von-Mises stresses obtained by numerical analysis and experiment agree well, the numerical simulation is proved to be valid.

• Nuclear Engineering and Technology
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• v.49 no.8
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• pp.1748-1751
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• 2017

Reduced activation ferritic/martensitic (RAFM) steels are widely applied as structural materials in the nuclear industry. To investigate hydrogen's effect on RAFM steels' elastic properties and the mechanism of that effect, a procedure of first principles simulation combined with experiment was designed. Density functional theory models were established to simulate RAFM steels' elastic status before and after hydrogen's insertion. Also, experiment was designed to measure the Young's modulus of RAFM steel samples with and without hydrogen charging. Both simulation and experiment showed that the solubility of hydrogen in RAFM steels would decrease the Young's modulus. The effect of hydrogen on RAFM steels' Young's modulus was more significant in water-quenched steels than it was in tempering steels. This indicated that defects inside martensite, considered to be hydrogen traps, could decrease the cohesive energy of the matrix and lead to a decrease of the Young's modulus after hydrogen insertion.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.413-422
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• 1997

Fire characteristics of a typical apartment building in Korea was studied through full scale experiment and zone model simulation. The fire was ignited at the living room and allowed to spread to other parts of a single unit in a five storied apartment building. Various data including temperatures, species concentrations, and images were collected in the experiment. A zone model(CFAST) was used to analyze the same apartment building that represents the average households in Korea. The results were compared with a full scale experiments. While CFAST allows one compartment involved with fire, the experiment allowed the fire to spread to other compartments. Therefore, the comparison between experimental data and Zone-Model data is valid until the living-room fire spread to other parts of the apartment. Flashover occurred at approximately 380 seconds in a fire experiment, and at approximately 420 seconds in Zone-Model. Based on all of data between experimental data and Zone-Model data, it is concluded that the safe escape time is about 250 seconds.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.8
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• pp.641-651
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• 2003

In order to assess the reliability of a building energy simulation program (TRNSYS) from the standpoint of user, a set of verification experiment and calculation of cooling load for a test space is carried out. This work is a complement of the previous study that dealt with heating load for the same space. The test space is kept airtight to eliminate the source of uncertainties in modeling. A window-mounted, on/off controlled air-conditioner is used for cooling, whose performance has been established a priori. The calculation encompasses two models for evaluating cooling load in TRNSYS: energy rate control and temperature level control. Comparison of the total cooling loads obtained from different sets of experimental data enables to validate the measurements. The experimental result shows that the latent load is fairly large even in the absence of apparent air change in the space, which needs to be clarified. Each of hourly and daily accumulated sensible loads is compared between the experiment and two calculation models. Despite an inconsistency associated with solar irradiation, both of the models agree favorably with the experiment within a tolerance, illustrating their capability of properly predicting space thermal loads.

• Journal of Korean Elementary Science Education
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• v.36 no.1
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• pp.1-15
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• 2017

The purpose of this study is to analyze the problems of land and sea breeze model experiment that has presented in $5^{th}$ grade curriculum in chapter "Weather and our lives" and makes better model simulation so that learners can have better and more effective way to study it. To survey the opinions from dedicated teachers about land and sea breeze model experiment, we produced the survey through interview with science exclusive teacher from M elementary school. An elementary science education expert, 3 men of science EdD modified and complemented survey and started Delphi survey to 12 science teachers who have career teaching more than 3 years. The problems found in this survey were 'one heat bulb, short heating time, small temperature difference of water and sand, lack of class time, empty space between sand and water, back of transparent boxes, little amount of scent and the location of the it' etc. But the most of all, it is hard to see the successful result of the experiment. Based on these kinds of investigations, and lots of trial and error, redesigned the new model experiment that has the most similarity to the real one and high probability of success. According to this, it was able to see the smoke forms horizontal movement along the sand and the smoke goes in one circulation cycle. through this experiment, we made a conclusion that although those scientific experiments in textbook were developed through lots of considerations of expert, to consider the aspect of consumer, it needs to reach the educational agreement about simulation experiment so that It can lead to successful experiment and high quality education.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.11
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• pp.1100-1107
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• 2007

In this study, a method to characterize material properties of adhesive that is used in a layered plates bonding process is developed by combined evaluation of experiment, simulation and optimization technique. A small bonded specimens of rectangular plate are prepared to this end, and put into a thermal loading conditions. $Moir{\acute{e}}$ interferomety is used to measure submicron displacements occurred during the process. The elevated temperature is chosen as control factors. FE analysis with constant values for the adhesive materials is also carried out to simulate the experiment. Significant differences are observed from the two results, in which the simulation predicts the monotonic increase of the bending displacement whereas the measurement shows decrease of the displacement at above $75^{\circ}C$. In order to minimize the difference of the two, material parameters of the adhesive at a number of different temperatures are posed as unknowns to be determined, and optimization is conducted. As a result, optimum material parameters are found that excellently matches the simulation and experiment, which are decreased with respect to the temperature.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.6
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• pp.474-480
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• 2008

Recently, rods having irregular sections more complex than a rectangle or ellipse are necessary to produce mechanical parts. The cold shaped drawing process is used to obtain shaped drawn products with high levels of dimensional accuracy and quality. A cross roller guide, considered in this study, is one of the parts produced by shaped drawing process. A cross roller guide has a linear bearing system that rolls along a guide way. A cross roller guide is one of the most important components in terms of equipment because the quality of the product influences the precision linear motion. Therefore, the final dimensional accuracy of the linear rail in the shaped drawing is very important. The objective of this study is to find the optimized die angles to improve the dimensional accuracy and straightness of the final shaped drawn product. In order to achieve the aim of this study, design of experiment, FE-simulation, and the Taguchi method were used. Based on the analytical results, shaped drawing experiment has been performed to verify the result.

• Journal of Mechanical Science and Technology
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• v.20 no.10
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• pp.1576-1589
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• 2006

Most of surface water ways in Egypt suffer from the infestation of aquatic weeds especially submerged ones which cause lots of problems for the open channels and the water structures such as increasing water losses, obstructing the water flow, and reducing the efficiency of the water structures. Accurate simulation of the water flow behavior in such channels is very essential for water distribution decision makers. Artificial Neural Network (ANN) has been widely utilized in the past ten years in civil engineering applications for the simulation and prediction of the different physical phenomena and has proven its capabilities in the different fields. The present study aims towards introducing the use of ANN technique to model and predict the impact of the existence of submerged aquatic weeds on the hydraulic performance of open channels. Specifically the current paper investigates utilizing the ANN technique in developing a simulation and prediction model for the flow behavior in an open channel experiment that simulates the existence of submerged weeds as branched flexible elements. This experiment was considered as an example for implementing the same methodology and technique in a real open channel system. The results of current manuscript showed that ANN technique was very successful in simulating the flow behavior of the pre-mentioned open channel experiment with the existence of the submerged weeds. In addition, the developed ANN models were capable of predicting the open channel flow behavior in all the submerged weeds' cases that were considered in the ANN development process.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.8
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• pp.26-30
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• 2008

The simulation and experiment for the fault current limiting characteristics of the superconducting fault current limiter (SFCL) using the magnetic coupling of series connected two coils were performed. The magnetic fluxes generated from two coils were canceled out during a normal time. However, the resistance generation of high-Tc superconducting (HTSC) element after a fault occurrence allows the magnetic fluxes of two coils and contributes to the fault current limiting operation. Through the computer simulation and the current limiting experiment for this SFCL, the operational current and the limiting impedance of the SFCL could be confirmed to be improved by adjusting the inductance ratio of two coils.