• Food Science and Biotechnology
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• 제18권4호
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• pp.959-964
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• 2009

Production of the antioxidant substances by Bacillus polyfermenticus SCD was investigated using shake-flask fermentation. The one-factor-at-a-time method was first employed to determine the key ingredients for optimal medium composition, then further investigation of the medium composition was performed using response surface methodology (RSM). The antioxidant activity was measured using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assays. After screening various elements, fructose, tryptone, and $MgSO_4\;7H_2O$ were chosen as the main factors for study in the statistical experimental design. Central composite design (CCD) was then used to determine the optimal concentrations of these 3 components. Under the proposed optimized medium containing 2.8% fructose, 1.34% tryptone, 0.015% $MgSO_4\;7H_2O$), 0.5% NaCl, and 0.25% $K_2HPO_4$, the model predicted an antioxidant activity of 80.5% ($R^2=0.9421$. The actual experimental results were in agreement with the prediction.

• 정보관리학회지
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• 제30권1호
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• pp.71-92
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• 2013

본 연구는 도시와 농어촌 각 청소년 집단의 정보 요구를 충족시키는 학교도서관 정보 서비스 방안을 제시하는 것을 목적으로 두 청소년 집단의 일상 정보 행태를 비교하였다. 특히, 두 청소년 집단의 일상에서의 정보 추구 행태뿐만 아니라 정보의 장의 종류와 정보의 장 형성을 방해하는 요인도 함께 비교하였다. 이를 위하여 본 연구는 정보 활용 일지와 반구조적 심층 인터뷰를 이용하여 두 청소년 집단의 일상 정보 행태의 특성을 조사하였다. 본 연구에서 제시된 정보 서비스 방안들은 추후에 도시와 농어촌의 학교도서관에서 정보 서비스를 기획하는데 활용될 것이라 기대된다.

• 한국터널지하공간학회 논문집
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• 제16권6호
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• pp.533-542
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• 2014

본 연구에서는 Gehring, CSM, NTNU 모델을 이용한 디스크 커터 수명 예측 방법과 각 모델이 가지는 특징을 살펴보았다. 디스크 커터 수명에 크게 영향을 주는 요소인 관입깊이, 암석의 일축압축강도, 마모지수의 변화가 각각의 예측 모델들에 미치는 영향을 분석하였다. 디스크 커터 수명은 1회전당 관입깊이에 선형적으로 증가하였고, 일축압축강도의 증가에 따라 감소하는 경향을 보였다. 마모지수인 CAI 값이 증가함에 따라 Gehring과 CSM 모델에서의 디스크 커터 수명은 감소하였으나, CLI 값이 증가할수록 NTNU 모델의 디스크 커터 수명은 증가하는 경향을 보였다. 그리고 실제 현장 자료를 이용하여 디스크 커터 수명을 상호 비교하였다.

• 한국정밀공학회지
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• 제29권6호
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• pp.626-631
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• 2012

In this study, fatigue life of the motor block bracket units for KTX-Sancheon trains was assessed. Design evaluation for railway structures was performed based on the UIC 566 regulation, and test and evaluation of fatigue life in welded parts was performed in accordance with standard ERRI B 12/RP17 and ERRI B 12/RP60. The actual vehicle dynamic stress testing was executed in KTX-Sancheon service line with the service operating speed. The dynamic stress was measured with commercial data acquisition system (MGC plus). The cumulative damage was evaluated by applying standard BS 7608 - Class F and cycle counting was used rain-flow counting method. As a result, the motor block bracket units for KTX-Sancheon trains was designed to fit the regulation and the safety of fatigue life for 30 years, assuming that KTX-Sancheon trains travels 600,000km annually, were confirmed under current operating conditions.

• Journal of the Korean Data and Information Science Society
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• 제23권1호
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• pp.131-142
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• 2012

우리나라는 이미 고령화사회를 넘어 고령사회로 향하고 있어 노인의 생활전반만족도에 대한 사회적 관심이 지속적으로 증대되고 있다. 본 연구의 목적은 보건복지가족부에서 실시한 "2008년도 노인 생활실태조사" 자료를 이용하여 노인의 인구통계학적 특성, 삶의 영역별 만족도, 소득원 등이 노인의 생활만족도에 영향을 미치는지를 분석하는 것이다. 분석결과 노인의 인구통계학적 특성, 신체 및 정신건강 수준, 경제활동 및 경제수준, 여가활용, 사회적 관계 등의 요인이 노인의 생활만족도에 유의한 영향을 미치는 것으로 나타났다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.114-119
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• 2004

Endbeam is an important structural member of freight bogie for the support of service loading. In general, more than 25 years' durability is necessary. However, endbeam occur fatigue fracture in dynamic stress concentration location because comparatively strength and stiffness are low. Therefore, structure analysis is performed to evaluate structural problem of endbeam and local strain range as durability analysis. The number of cycles is extracted concerning the bogie in operation by measurement dynamic stress time history on critical part which is crack initiation in actual fact. At this time rainflow cycle counting is used to consider change of stress for operating condition. Based on the fatigue life curves and the stress analysis, the fatigue life of the endbeam is predicted and compared with the experimentally determined fatigue life, resulting in a fairly good correlation.

• 경영과정보연구
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• 제7권
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• pp.227-245
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• 2001

The object that we have researched the design for a long life of product is to search for the method to cope with the various environment problems where our mankind is confronting in the field of Production Design. The environment problem on earth is affecting seriously the enterprise which produces the product, the user who consumes it and even the field of product design. Now we live our daily life with a lot of artifacts while the citification and modernization have been progressing around us. Especially, 20 century was the times of the highly advanced scientific civilization and industrialization. Therefore it affected decisively our life environment base nowadays. The result was that our human life became rich because of the advanced development of industry, productivity and distribution structure. On the other side, the industrial system in the period of these massive production and massive consuming is bearing various problems proportionally. Those are the depletion of resources and energy, earth environmental pollution and various kinds of waste. In addition, the material which cannot recycle is appearing at the large quantity. This is the actuality of now. Our subject is how product design will cope with it as counter measures and the subject is very important to our mankind and earth environment.

• KEPCO Journal on Electric Power and Energy
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• 제8권1호
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• pp.9-14
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• 2022

Social infrastructure facilities such as production, transportation, gas and electricity facilities may experience poor performance depending on time, load, temperature, etc. and may require maintenance, repair and management as they are used. In particular, in the case of transformers, the process of managing them for the purpose of preventing them from failing is necessary because a failure can cause enormous social damage. The management of transformers should consider both technical and economic aspects and strategic aspects at the same time. Thus, it applies the Asset Management concept, which is widely used in the financial industry as an advanced method of transformer management techniques worldwide. In this paper, the operation and power outage data were secured for the asset management of the transformer for distribution, and the asset status was analyzed. Analysis of asset status using actual operation and power outage data is essential for assessing the statistical life and failure rate of the facility. Through this paper, the status of transformer assets for arbitrary A group distribution was analyzed, and the end of life and replacement life were calculated.

• 한국가정과교육학회지
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• 제17권3호
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• pp.53-70
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• 2005

본 연구는 중학교 1학년 가정교과를 이수한 2학년 남녀 학생을 대상으로 중학교 가정교과와 식생활 단원에 대한 전반적인 인식과 식생활 단원에 대한 필요도, 난이도, 실생활에서의 활용 정도를 조사$\cdot$분석하여 식생활 단원의 효율적인 교수 학습 방안을 마련하고 새로운 교육과정을 편성하기 위한 기초 자료로 제공하는데 목적이 있다. 본 연구에서 얻어진 결과를 요약하면 다음과 같다. 가정교과 학습내용의 인식은 '조리, 세탁, 육아 등 가정생활에 필요한 기능을 배운다' $(38.9\%)$가 가장 높게 나타났고, 다음은 '건전한 생활 이념과 올바른 인간 형성에 관한 것을 배운다'$(27.5\%)$로 나타났다. 식생활 단원에 대한 학습내용의 인식은 '식생활 향상을 위한 식품 영양의 지식과 원리를 배운다'$(38.8\%)$가 가장 높게 나타났고, 다음은 '가정생활에 필요한 실질적인 기능을 배운다'$(30.7\%)$로 나타났다. 식생활 단원에 대한 필요도는 청소년의 식사(3.95), 청소년의 영양(3.89), 조리의 원리와 음식 만들기(3.88)순으로 대체로 높은 편이며 식생활 단원 전체와 모든 영역에서 여학생이 높게 나타났다. 식생활 단원에 대한 난이도는 청소년의 영양(2.78), 청소년의 식사(2.70). 조리의 원리와 음식 만들기(2.59) 순으로 중간 정도의 수준이었다. 여학생이 식생활 단원 전체를 더 어렵게 인식하고 있었으며, 또한 청소년의 영양과 청소년의 식사를, 남학생은 조리의 원리와 음식 만들기를 더 어렵게 인식하는 것으로 나타났다. 식생활 단원에 대한 실생활의 활용도는 청소년의 식사(3.28), 조리의 원리와 음식 만들기(3.15), 청소년의 영양(3.07) 순으로 필요도보다 약간 낮은 수준이었다. 남학생이 식생활 단원 전체의 활용도가 높게 나타났으며, 또한 청소년의 영양과 청소년의 식사를, 여학생은 조리의 원리와 음식 만들기가 높게 나타났다. 식생활 단원의 필요도 및 난이도와 활용도의 상관관계는 식생활 단원의 학습내용에 대하여 학생들의 필요도가 높을수록 식생활 단원의 모든 영역의 실생활활용도가 높게 나타났고 어렵게 인식할수록 식생활 단원의 모든 영역의 실생활 활용도가 낮게 나타났다.

• 한국치위생학회지
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• 제6권1호
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• pp.63-77
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• 2006

The purpose of this study was to prepare a student and education guideline by examining the college life satisfaction of students studying dental hygiene. Subjects were students going to dental hygiene-related department of three colleges in the Gwangju and Jeonnam areas. College life and life satisfaction was examined at general characteristics. The following results were obtained. 1. Subjects included 35.7% of 1st grade, 33.4% of 2nd grade, and 30.9% of 3rd grade. In the health state, average accounted for the highest percent(76.9%); in the student's associates, a little for the highest percent(76.8%); and in the participation in clubs, no participation for the highest percent(77.1%). 2. For motives to select the dental hygiene, good employment after graduation accounted for the highest percent(61.0%). The highest desired employer was a dental clinic(33.5%), and the highest desired duration was a whole life(61.0%). 3. According to the grade, satisfaction was significantly different in social recognition, major in education, professor, facilities, professor-student, career, and college development(pE0.05). 4. According to the school record, satisfaction was significantly different in social recognition, major in education, professor, professor-student, career, college development, and general life(pE0.01). 5. According to the student's associates, satisfaction was significantly different in social recognition, major in education, professor-student, and general life(pE0.01). 6. According to the participation in clubs, satisfaction was significantly different in professor, facilities, college development, and religious life(pE0.05). In conclusion, as students were in the lower grade, made good school record, had happier associates, and participated in clubs more actively, their satisfaction at college life became higher. Accordingly, professors and school authorities should strive to examine students' actual problem and discuss and resolve them in order to help their effective school life.