• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.18-21
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• 1996

This paper deals with experimentation on static test of linear induction motor for the propulsion system of UTM(Urban Transit Maglev). It is very important that vertical force zero effects to levitation field of maglev. Because it is continuous for air gap 11mm of levitated maglev vehicle. Then we found the slip frequency that the vertical force zero due to it is variable. Thus we had compared between simulation value and experiment value for lim by static test Jig.

• 대한기계학회논문집B
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• 제26권8호
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• pp.1123-1131
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• 2002

An experimental study on the performance and instability development characteristics of a centrifugal compressor equipped with a cambered variable diffuser has been performed with varying diffuser vane angles. The test was conducted at the design speed of 20,800 rpm and the 80% design speed of 16,640 rpm for 5 diffuser angles : 65$^{\circ}$, 70$^{\circ}$, 75$^{\circ}$, 77.5$^{\circ}$, 80$^{\circ}$ The steady performance test results showed that choking mass flow rate decreases and total pressure ratio increases with a narrowed surge margin as the diffuser vane angle increases. Unsteady pressures were measured using high-frequency pressure transducers at the inducer and the diffuser throat to investigate the instability phenomena such as rotating stall and surge inside the compressor. From the unsteady measurements, it is found that the transient process from rotating stall to surge was mainly affected by diffuser angles. The results of the present study can be applied to the instability control of the centrifugal compressors using a variable diffuser.

• 한국식생활문화학회지
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• 제9권3호
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• pp.289-301
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• 1994

The purpose of this study was to investigate housewives' perception, interest and consumption of organic food, and to identify the variables influencing on them. The sample was selected from 411 housewives living in Seoul from 1st of September to 20th of September in 1993. Used statistical methods were frequency, percentage, mean, Cronbach's ${\alpha}$, factor analys, ANOVA, Duncan's multiple range test, t-test, correlation, regression analysis and Path analysis. The major results are as follows: 1) Housewives' perception degree of organic food in its variety, easy availability and contribution to health was relatively high level, but price level, reliability and packing condition was somewhat low level. Out of housewives' many images of organic food, taste health care, quality and necessity factors can be implicated. 2) Housewives' interest degree of organic food is somewhat high level 3) Housewives' consumption degree of organic food was relatively low level and was affected by their perception of oraganic food. 4) Frequency to use seasonings was the major independent variable which influenced to housewives' perception degree of organic food, while recognition on enviornmental contamination was the major independent variable which influenced to their interest degree of organic food, and their total perception on organic food was the major independent variable which influenced to their consumption degree of oragnic food. Therefore, it is considered that their total perception to it can decide the demand of organic food 5) Housewives' perception and interest degree of it was the major intervening variable which influenced to their consumption degree of oragnic food.

• 가정과삶의질연구
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• 제10권1호통권19호
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• pp.27-42
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• 1992

This study focused on consumer information search activity and consumer's post-purchase satisfaction. For these purpose, a survey was conducted suing questionaires on 430 homemakers that lived in seoul. Statistics used for data were Frequency Distribution. Percentile, Mean, One-way AAANOVA., Scheffe-test, T-test, Pearson's correlation. Multiple Regression Analysis and Multiple Classification Analysis. The major findings were ; 1) The level of each amount information search was lower than average. And the level of consumer's post-purchase satisfaction was a little higher than average. 2) On amount of "noncommercial-personal" information search, the influencing variables were desire to seek information, education, brand royalty in turn. These three variables explained 7% of dependent variable's variance. 3) On amount of "noncommercial-media" information search, the influencing variables were desire to seek information, amount of internal information, education, occupational status in turn. These variables explained 14% of dependent variable's variance. 4) On amount of "commercial-personal" information search, the influencing variable was desire to seek information, and this variable explained 3.1% of dependent variable'a variance. 5) On amount of "commercial-media" information search, the influencing variables were desire to seek information, education, amount of internal information in turn. These three variables explained 12.1% dependent variable's variance. 6) Resulting from multiple classification analysis, influencing variables on consumer's post-purchase satisfaction were amount of noncommercial-media information search and printed media search, and brand royalty. These three variables explained 9% of dependent variable's variance. Furthermore, througout all the subareas of consumer's satisfaction, the amount of noncommercial-media information search was the most influencing variable.

• 한국생산제조학회지
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• 제8권2호
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• pp.73-79
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• 1999

Most of mechanical structures are combined of substructures such as beams and/or plates. There are few systems with unibody structures but are many systems with united body structures. Generally the dynamic a nalysis of whole structures is performed under alternation load. In the structure design, the analysis of each bolted joint is more important than others for zero severity. This paper presents the analysis method of contact stress distribution factor in the bolted joint with variable fastening torque on joints in the structure. At first, a static vibration test was performed to find out a nominal stress of bolt jointed plates from the relationship between natural frequency and nominal stress. Then a contact stress was computed at contact point between bolt and plate in the structure. It is believed that the proposed method has promisiong implications for safer design with index of contact stress distribution factor and has merits for cost-down and saving time at the beginning of vehicle development.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1998년도 춘계학술대회 논문집
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• pp.298-303
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• 1998

Most of mechanical structures are combined of substructures such as beam and/or plates. There are few system with unibody structures but are not a few systems with united body structures. Generally the dynamic analysis of whole structures is perform ed under alternating load. However, the analysis of each joint area is more important than others for zero severity. This paper presents the results of analysis of concentration stress in bolt jointed structure with variable preload. At frist, a static vibration test was performed to find out a nominal stress of bolt joint ed plates from the relationship between natural frequency and nominal stress. Then a concentration stress was computed at contact point between bolt and plate in the structure. It is believed that the proposed method has promising implications for safer design with fatigue quality index of stress concentration factor and has merit for cost down and saving time at the beginning of vehicle development.

• 한국소음진동공학회논문집
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• 제20권11호
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• pp.995-1000
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• 2010

With the development of the auto industry, the automobile manufacturers demand to shorten development period and reduce the cost. Compared with the traditional method, applying the virtual prototype is more economical. This paper presents a method for parameters sensitivity analysis and optimizing the performance of vehicle noise and vibration. The existing design processes were repeatedly analyzed with a focus on vehicle performance to decide the design parameters of dimension, thickness, mounting type of body and chassis systems in the vehicle development period. This paper describes the prediction technique of vehicle performance using L18 orthogonal array layout, quality deviation analysis and parameter sensitivity analysis for robust design. This paper analyzed the performance correlation equation through the frequency and sensitivity database according to a design factor change. The new concept is that the performance prediction is possible without repeated activities of test and analysis. This paper described the parameter analysis applications such as bush dynamic stiffness and bush void direction of rear suspension. Design engineer could efficiently decide the design variable using parameter analysis database in early design stage. These improvements can reduce man hour and test development period as well as to achieve stable NVH performance.

• 한국의류학회지
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• 제44권1호
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• pp.141-158
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• 2020

This study examines age differences with respect to consumers' clothing purchase behavior. First, the differences of age groups were investigated according to clothing purchase behavior, which include purchase item, purchase price, purchase channel, information resources, purchase frequency, and monthly clothing expenditures. Second, the differences of segmented groups by age variable were investigated according to clothing purchase behaviors after segmenting consumers by clothing shopping orientation. An on-line survey was conducted from July 2 to July 10, 2019, and 500 data were collected from adults aged 20s to 60s who had bought their own clothes within one year. Data were analyzed by descriptive statistics, factor analysis, reliability analysis, chi-squared test, ANOVA and Duncan-test using SPSS 21.0. This findings showed that there were significant differences in purchase item, purchase price, purchase channel, purchase frequency, and information resources according to age group. As a result of segmentation by shopping orientation, consumers were classified into three groups of high shopping involvement, low shopping involvement, and economic pursuit. In addition, there were partly significant differences in clothing purchase behavior according to classified groups by age variable.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1791-1793
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• 2003

In order to analyze the dynamic characteristics of ground impedance in large grounding system for lightning and surge protections, a novel method for measuring the ground impedance as a function of frequency was proposed. The experiments were carried out in the grounding system composed of ground rods and mesh grids. The test current was injected by the variable frequency inverter whose frequency is linearly controlled in the range of $5{\sim}500$kHz. The ground impedance and frequency response of the grounding system were mainly caused by the inductive current flowing through grounding conductors over the frequency of 2002. In the combined grounding system of rods and mesh grids, inductive component of ground impedance was significantly decreased. It was fumed out that the grounding system is effective for the surge protection.

• 한국전산구조공학회논문집
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• 제28권3호
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• pp.275-281
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• 2015

본 연구에서는 동조액체기둥감쇠기의 비선형감쇠항을 등가점성감쇠항으로 치환한 등가선형 동조액체기둥감쇠기 모델을 유도하였으며 동조액체기둥감쇠기의 동적거동인 고유진동수와 감쇠비를 이론적으로 파악하였다. 동조액체기둥감쇠기에 일정한 전기장을 형성한 후 동조액체기둥감쇠기의 수직운동에 의해 발생되는 가변전압을 측정하여 수조 내부의 수위로 변환하는 식을 유도하였다. 또한 본 연구에서 제안한 동조액체기둥감쇠기의 수위측정 시스템의 타당성을 검증하기 위하여 고가의 전기 용량식 파고계와 비교 및 검증하였다. 마지막으로 본 연구에서 제안한 수위측정 시스템을 동조액체기둥감쇠기에 적용, 진동대 실험을 실시하여 고유진동수와 감쇠비를 파악하였고, 이론상의 고유진동수와 실험상의 고유진동수가 일치하였음을 확인하였으며, 진동수비 변화에 따른 동조액체기둥감쇠기의 감쇠비 변화를 확인하였다.