• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 초전도 자성체
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• pp.7-10
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• 2002

We designed the flyback planar transformer, which had 8W capacity, with 70V input voltage and 8.2V output voltage for the establishment of design method and the confirmation of application possibility. The numerical value of inductance measured under the switching frequency of 120 kHz was 1650 ${\mu}H$, which was the inductance efficiency of 85~87% against theoretical value. The A.C. resistance of primary and secondary coil was 4.2 ${\Omega}$ and 0.25 ${\Omega}$ respectively. On the other hand, the quality factor for each wound numbers showed quite a high value of 158 and 75 respectively. And the Coupling Factor was 0.96~0.97 under 120 kHz switching frequency. And the shape of the output wave of the planar transformer at 70V input voltage was a stable square wave.

• Journal of Electrical Engineering and Technology
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• 제3권2호
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• pp.243-253
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• 2008

This paper deals with the analysis, design, and implementation of a single phase AC-DC Zeta converter with high frequency transformer isolation and power factor correction(PFC) in two modes of operation, discontinuous current mode of operation(DCM), and continuous current mode of operation(CCM). A Digital Signal Processor(DSP) based implementation is carried out for validation of the Zeta converter developed design in discontinuous mode of operation. A comparison of both modes of operation is presented for a 1kW power rating from the point of view of steady state and dynamic behavior, power quality, simplicity, control technique, device rating, and converter size. The experimental results of a developed prototype of Zeta converter are presented for validation of the developed design. It is observed that CCM is most suitable for higher power applications where it requires some complex control and sensing of the additional variables.

• 대한환경공학회지
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• 제39권11호
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• pp.641-649
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• 2017

본 연구에서는 오염원의 변화 특성이 다양한 임진강유역을 대상으로 통계분석을 이용하여 상관분석, 주성분 및 요인분석, 군집분석을 통해 수질특성을 파악하였다. 신천3 지점의 평균 수질농도가 BOD 13.4 mg/L, COD 19.9 mg/L, TN 11.145 mg/L, TP 0.336 mg/L, TOC 14.2 mg/L로 높게 나와 전체 유역 중 신천 유역에 대한 집중적인 수질관리가 필요한 것으로 나타났다. 전체 수질측정 자료의 상관분석 결과 COD는 TOC, BOD, TN 수질인자와 유의한 상관관계를 보여 유기물과 영양염류인자간의 상관성이 높은 것으로 나타났다. 주성분분석 결과 전체 측정소 자료는 81.221%로 2개의 주성분, 계절별 자료는 96.241%로 3개의 주성분이 추출되었다. 요인분석 결과 전체 측정소 자료와 계절별 자료의 수질영향 요인은 공통적으로 BOD, COD, TN, TP, TOC 항목이 나타났다. 시 공간적 군집분석 결과 계절별 특성 및 토지이용에 따라 각각 4개, 3개 그룹으로 나타났다. 본 연구는 임진강유역을 중심으로 8년간 시 공간적 특성을 고려한 수질 요인을 분석한 것으로 향후 유역환경변화에 따른 임진강 유역의 수질 변화를 이해하기 위한 기초 분석 자료가 될 것이다.

• 한국의상디자인학회지
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• 제11권3호
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• pp.153-162
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• 2009

The purpose of this study was to examine the differences in the service quality evaluation on the skill and expert, the shop facilities and atmosphere, the time and access, and the price and benefit of a nail care shop by age, income, spendings of appearance and a nail care, and a regular nail care. The survey was performed with questionnaires and the subjects were was 240 consumers who used the nail care. The data were analyzed by frequencies, F-test, T-test, Factor Analysis, one way ANOVA. The results of the study were as follows: Service quality evaluation were classified four factors- the price and benefits, the skill and expertness, the facilities and atmosphere, the time and access. There were no statistically significant differences in the price and benefits by age, income, spendings of appearance and a nail care, and a regular nail care, but there were statistically significant differences in the skill and expertness, the facilities and atmosphere, and the time and access. The service quality on the time and access was evaluated as high by the consumer in the 30s, with more income, and with high appearance and nail care spendings. The service quality on the shop facilities and atmosphere was evaluated as high by the consumers with high nail care spending. The consumers with a regular nail care evaluated the service quality on the skill and expertness, the time and access, the shop facilities and atmosphere as high.

• 분석과학
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• 제19권6호
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• pp.544-552
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• 2006

본 논문은 소형챔버법을 이용해 바닥재 종류에 따른 방출농도특성을 알아보고자 수행되었다. 환경학적 관심사가 높은 개별 휘발성유기화합물(VOC) 및 총휘발성유기화합물(TVOC)을 측정대상물질로 선정하여 HPLC 및 GC/MSD를 이용하여 분석하였다. 바닥재에서 방출된 TVOC 및 포름알데히드(HCHO)의 평균방출농도는 각각 $0.3mg/m^2{\cdot}h$와 $0.2mg/m^2{\cdot}h$로 나타났으며 37개 바닥재 모두 방출기준을 만족하는 것으로 조사되었다. TVOC 방출농도는 PVC Sheet, PVC Tile, 마루 순으로 나타났으며, 반면 HCHO 방출농도는 PVC 계열보다 마루 제품에서 높게 나타나는 경향을 보였다.

• 한국식생활문화학회지
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• 제1권2호
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• pp.142-156
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• 1986

The purpose of the present study was to investigate the value evaluation of food in urban Korean adolescents. The conclusions drawn from the analysis of values of foods are as follows: 1. There are five factors drawn from the analysis of values of foods, that is, subjective evaluational factor. Objective factors are social factor, economic factor, quality attribute factor, and freguency of food intake factor. And it has been revealed that there is some relationship between these factors. The subjective evaluational variable depends most strongly on the sensory variable, especially taste, flavor, color and shape of food, described in the order of influence. It also depends on the experiential frequency of intake. 2. With regard to the attitude of evaluation of food, there is a considerable difference between junior high school students and high school students, and between male and female students, This difference can be noticed in almost all the variables dealt with in this study, especially in the subjective evaluational aspect, experiential aspect, and social aspect, A significant difference was found between junior high school students and high school students and between male and female students on both subjective and objective values of foods. Male students valued food which brought about a 'Satiety' more so than female. And consequently, they take such kinds of foods more frequently. More female students than male students and more junior high school students than high school students have a strong conception of the socio-cultural value of foods, that is, the spatial and temporal symbol of foods.

• 한국지역사회생활과학회지
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• 제20권3호
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• pp.397-411
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• 2009

The use of local product foods and fresh-cut products, the dietitian's recognition, the required items and the quality for school foodservice was investigated to increase the consumption of high-quality agricultural products. Data from 578 elementary schools, 228 middle schools and 116 high schools were collected by school foodservice personnels in each regional Education Administration in Gyeong-gi province. The first criteria of buying food materials was reliability/safety for all school foodservice. The second criteria were the origin of the product and freshness/ripeness for elementary and middle schools and high school, respectively. The most important consideration for selecting a supplier was the quality of the material. The appearance/status of the food was the first factor for buying food materials. The origin and the seasonality were very important for buying farm products. Dietitians in Gyeong-gi province recognized the local products, and used them weekly. The advantages of using local products were the quick supply, freshness and safety. On the other hand, the disadvantages were the lack of information and the uncertainty of supply. Sixty eight percent of the subjects had experienced the high-quality agricultural products in school meals, but the frequency was low. The main reasons for not servicing high-quality agricultural products were the high cost and the lack of trust on the quality. Among fresh-cut products, seasonings and root vegetables were purchased most frequently, but leaf vegetables was 5.7% only. The purchase of fresh-cut products was not frequent, but usually satisfied. The advantages of fresh-cut products were the reduced workload and waste, but the reason for not using them were poor hygiene and the high price. The diverse supply system and the promotion of the local product foods would be necessary since the most food materials were purchased through suppliers. In addition, the problems related to the high cost and distrust should be resolved to expand the consumption of the high-quality agricultural products and the fresh-cut vegetables. The institutions for certifying the quality should be needed to increase the confidence of these products.

• 한국콘텐츠학회논문지
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• 제10권1호
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• pp.426-435
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• 2010

이 연구는 워터파크의 서비스품질 척도를 개발하여 타당도와 신뢰도를 검증하는데 목적을 두고 있다. 설문지의 타당도를 검증하기 위하여 전문가회의 및 패널조사, 탐색적 요인분석과 확인적 요인분석을 실시하였으며, 신뢰도를 검증하기 위하여 문항분석, 평가자간 신뢰도, 그리고 내적 일관성 신뢰도 검증을 실시하였다. 이상과 같은 연구방법 및 절차를 통하여 이 연구에서는 다음과 같은 결론을 도출하였다. 첫째, 서비스품질 척도의 타당도는 매우 높다. 즉, 서비스품질 척도는 쾌적성 청결성, 안전성, 종사원, 가격, 프로그램, 주시설, 부대시설, 접근성, 판촉으로 탐색 확인되었으며, 쾌적성 청결성 요인의 설명력이 가장 높다. 둘째, 서비스품질 척도의 신뢰도는 매우 높다. 즉, 서비스품질 척도는 문항과 영역간 문항과 총점간 상관정도가 높으며, 내적 일관성 신뢰도는 판촉 요인을 제외하고 Cronbach's $\alpha$값이 .603이상이다. 판촉 요인의 신뢰도는 .60이하이다. 이상의 내용을 종합해 보면, 서비스품질 척도는 경험적으로 매우 타당하고 신뢰할 수 있는 척도임을 알 수 있다. 워터파크의 서비스품질을 향상시키기 위해서는 서비스품질 주요 요인을 파악하여 경영혁신에 반영해야 할 것이다.

• 대한간호학회지
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• 제38권3호
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• pp.474-482
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• 2008

Purpose: The purposes of this study were; 1) to test the validity and reliability of the Korean version of Rantz's Observable Indicators of Nursing Home Care Quality Instrument (ONHQ) and 2) to evaluate the quality of Korean nursing homes. Methods: The study employed a three-phase methodological research design. 1) The original instrument of Rantz's. ONHQ was translated into Korean and modified by Korean nursing home experts. 2) A pilot study using the modified instrument was done in 20 nursing homes to examine inter-rater reliability. 3) The validity and reliability were tested.in 98 nursing homes. Results: Seven factors were extracted through factor analysis: 'communication', 'care delivery', 'grooming', 'odor, 'environment-basics', 'environment-access', and 'environment-homelike'. These factors explained 86.07% of the total variance. Cronbach's alpha coefficient of the 30 items was .97 indicating a high internal consistency of the instrument. Inter-rater reliability according to Kappa was .82. The average score of nursing home quality was 112.07 indicating an average range of quality level. Conclusion: The Korean version of the ONHQ was identified as a tool with a high degree of validity and reliability. This tool can be effectively used to assess the quality of nursing homes by professions as well as family members.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권3호
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• pp.155-160
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• 2000

The piezoelectric properties and the doping effect for$0.95Pb(Zr_xTi_{1-x})O_3+0.05Pb(Mn1/3Nb2/3)O_3$ compositions were studied. Also, the heat generation and the change of electromechanical characteristics, the important problem in practical usage, were investigated under high electric field driving. As a experiment results under low electric field, the values of kp and $\varepsilon33T$ were maximized, but Qm was minimized(Kp=0.57, Qm=1550) in the composition of x=0.51. In order to increase the values of Qm $Nb_2O_5$ was used as a dopant. As the result of that, the grain size was suppressed and the uniformity of grain was improved. Also, the values of kp decreased, and the values of Qm increased with doping concentration of $Nb_2O_5$. As a experiment results under high electric field driving, when vibration velocity was lower than 0.6[m/s], the temperature increase was $20[^{\circ}C]$, and the change ratio of mechanical quality factor was less than 10[%]. So, its electromechanical characteristics was very stable. Conclusively, piezoelectric ceramic composition investigated at this paper is suitable for application to high power piezoelectric devices.