• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.7
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• pp.55-61
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• 2014

This paper presents a method to reduce the stray loss of core Tie-Plate of distribution power transformer. The method combines a 3-dimensional FEM with PSO(Particle Swarm Optimization) algorithm to determine the shape of the Tie-Plate that minimizes eddy current and flux-leakage losses. To verify the method a 24MVA distribution(cast-resin) transformer was simulated using one objective function and two design variables with some constraints. The final optimized Tie-Plate has nine($3{\times}3$) slots of 10mm width, 15mm thickness and 25mm distance. After four iterations, the Tie-Plate loss was reduced to about 21 % of the original.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.932-934
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• 1993

Optimum pole shape is designed to increase the levitation and propulsion force of magnetic levitation systems. Evolution Strategy is introduced as optimization method. Evolution Strategy is random based non-deterministic method, developed by combining Genetic Algorithm with Simulated Annealing. Trasnsrapid-06, which was developed in Germany, is referenced model to be analyze. Design variables are nodes which determine fields pole shape of a linear synchronous motor, and the model analyzed by F.E.M.

• Journal of Ocean Engineering and Technology
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• v.27 no.5
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• pp.36-42
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• 2013

We present the optimum design for the cross-sectional(sizing) and shape optimization of truss structures with natural frequency constraints. The optimum design method used in this paper employs continuous design variables and the Harmony Search Algorithm(HSA). HSA is a meta-heuristic search method for global optimization problems. In this paper, HSA uses the method of random number selection in an update process, along with penalty parameters, to construct the initial harmony memory in order to improve the fitness in the initial and update processes. In examples, 10-bar and 72-bar trusses are optimized for sizing, and 37-bar bridge type truss and 52-bar(like dome) for sizing and shape. Four typical truss optimization examples are employed to demonstrate the availability of HSA for finding the minimum weight optimum truss with multiple natural frequency constraints.

• International Journal of Korean Welding Society
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• v.3 no.1
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• pp.8-16
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• 2003

A major concern in Gas Metal Arc (GMA) welding process is the determination of welding process variables such as wire diameter, gas flow rate, welding speed, arc current and welding voltage and their effects on the desired weld bead dimensions and shape. To successfully accomplish this objective, 81 welded samples from mild steel AS 1204 flats adopting the bead-on-plate technique were employed in the experiment. The experimental results were used to develop a mathematical model to predict the magnitude of bead geometry as follows; weld bead width, weld bead height, weld bead penetration depth, weld penetration shape factor, weld reinforcement shape factor, weld bead total area, weld bead penetration area, weld bead reinforcement area, weld bead dilution, length of weld bead penetration boundary and length of weld bead reinforcement boundary, and to establish the relationships between weld process parameters and bead geomery. Multiple regression analysis was employed for investigating and modeling the GMA process and significance test techniques were applied for the interpretation of the experimental data.

• The International Journal of Costume Culture
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• v.6 no.2
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• pp.93-104
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• 2003

The purpose of this study was to investigate the relationship between women's face satisfaction and makeup satisfaction, to disclose the differences of makeup satisfaction according to demographic variables, and to examine how makeup satisfaction was influenced by face satisfaction and demographic variables. The subjects were 200 women over age 17 living in Seoul and its peripheral areas. The results of this study were as follows: Face satisfaction were drawn three factors. Factor 1 was face contour satisfaction, Factor 2 was skin satisfaction, and Factor 3 was lips and eyes satisfaction. There were significant positive relationship between factors of face satisfaction and makeup satisfaction. Also, the face contour satisfaction was in positive correlation with satisfaction of features, and the skin satisfaction was in positive correlation with that of features. There were significant positive correlations between makeup satisfaction and face shape, eyes, nose, lips, chin, and cheek bone satisfaction. Face satisfaction didn't show significant difference according to demographic variables, but makeup satisfaction showed significant difference according to age and occupation. Face satisfaction was influenced by the facial face, clarity of skin, elasticity of skin, skin color, and ages. The explanatory power of the 4 variables were 24.5%. Makeup satisfaction was influenced by lips and eyes satisfaction, ages, and skin care level. The explanatory power of the 3 variables were 13.3%.

• Journal of Sport and Applied Science
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• v.5 no.2
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• pp.55-61
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• 2021

Purpose: This study aims to obtain basic data for conceptual establishment of sports participation and perceived benefits by considering prior research on the effects of sports participation to derive variables for perceived benefits of sports participants. Research design, data, and methodology: This study used an integrated literature review. A conceptual model is designed with reference to a prior study by adopting a guiding theory. Based on the key words. The literature collection was conducted online, and the reference period for the literature collection was for studies published between 2015 and 2020. Results: First, a total of seven related variables were derived from the literature analysis related to sports participation and physical benefits. Second, a total of six variables were derived from the literature analysis related to sports participation and mental benefits. Third, a total of four related variables were derived through a literature analysis related to sports participation and social benefits. Conclusions: Health fitness, objectified body consciousness, and social body shape anxiety, including body composition, approach physical benefits among perceived benefits through sports participation, and physical self-efficacy and physical self-concepts are related to physical benefits but are also shown to be related to mental benefits. And successful aging is seen to be close to social benefits and related to some mental benefits. Mental and social benefits can be seen as the variables derived from the results being related to the benefits, and more in-depth exploration of perceived benefits is needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.461-470
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• 2020

This study analyzed the determinants of land compensation costs using the CALS (Continuous Acquisition & Life-Cycle Support) system to generate data for the construction (planning, design, building, management) process. For analysis, variables used in the related research on land costs were used, which included eight variables (Land Area, Individual Public Land Price, Appraisal & Assessment, Land Category, Use District 1, Terrain Elevation, Terrain Shape, and Road). Also, the variables were analyzed using the machine learning-based Xgboost algorithm. Individual Public Land Price was identified as the most important variable in determining land cost. We used a linear multiple regression analysis to verify the determinants of land compensation. For this verification, the dependent variable included was the Individual Public Land Price, and the independent variables were the numeric variable (Land Area) and factor variables (Land Category, Use District 1, Terrain Elevation, Terrain Shape, Road). This study found that the significant variables were Land Category, Use District 1, and Road.

• International Journal of Fluid Machinery and Systems
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• v.2 no.1
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• pp.1-12
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• 2009

Surrogate modeling is applied to a compressor blade shape optimization to modify its stacking line and thickness to enhance adiabatic efficiency and total pressure ratio. Six design variables are defined by parametric curves and three objectives; efficiency, total pressure and a combined objective of efficiency and total pressure are considered to enhance the performance of compressor blade. Latin hypercube sampling of design of experiments is used to generate 55 designs within design space constituted by the lower and upper limits of variables. Optimum designs are found by formulating a PRESS (predicted error sum of squares) based averaging (PBA) surrogate model with the help of a gradient based optimization algorithm. The optimum designs using the current variables show that, to optimize the performance of turbomachinery blade, the adiabatic efficiency objective is improved substantially while total pressure ratio objective is increased a very small amount. The multi-objective optimization shows that the efficiency can be increased with the less compensation of total pressure reduction or both objectives can be increased simultaneously.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.121-123
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• 1996

Capacitor-run motor has a capacitor id series with the auxiliary winding for normal running connections. After the shape of stator and rotor are determined, the motor is designed with variables such as winding distributions or capacitance except punching variables. In this paper, the winding distribution and the turn ratio was taken as design variables because the winding distribution affects the torque and efficiency. And capacitance was selected as an additional variable. Simulation results show the validity of proposed method.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.240-245
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• 2001

In axiomatic approach for design evaluation, even if a mutual relation don't appear physical mapping of high level, it can appear in process mapping of low level through coupled PVs(Process Variables), but we must solve it for correct design evaluation. This paper handle a method for solving of coupled PVs by using axiomatic approach and CBR(Case-Based Reasoning). The methodology of proposal took still more shape through the instance of MCPs(Microcellular Plastics).