• 산업기술연구
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• 제43권1호
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• pp.7-13
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• 2023

Nowadays, traffic congestion is emerging as a major problem due to the rapid population growth and the increase in automobiles. The train is a convenient means of transportation that can efficiently solve these problems. Trains have been developed in line with human aspirations for a long time, but research on safety is still insufficient. This study aims to check safety by conducting static tests and fatigue tests on bogie frames, and to help develop bogie frames in the future. For the static test, a strain gauge was attached to the point where the local stress concentration was expected beforehand, and the result value was derived, compared with existing theories, and expressed as a Goodman diagram. In the fatigue test, a total of 10 million loads were applied over three stages, and no cracks appeared in the non-destructive test conducted after each stage. Both tests were conducted according to the strict test method of the bogie frame presented by the UIC Code. It satisfied both fatigue life and strength evaluation criteria and was judged to be a bogie frame usable for safe train production.

• 한국비블리아학회지
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• 제27권3호
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• pp.51-73
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• 2016

본 연구는 공공도서관 사서들이 어려움을 느끼고 있는 평생교육 단위직무를 파악하고 동시에 재교육이 필요한 교육 내용에 대한 우선 순위를 맨휘트니(Mann Whitney U-test), 다중회귀분석(Multiple regression analysis)과 AHP(Analytic Hierarchy Process) 분석을 통해 제시하였다. 첫번째, 조사 대상 사서의 87%가 평생교육 직무는 보통이거나 어렵다고 인식하고 있었으며, 단위 업무별로는 운영계획수립을 가장 어려운 직무로 생각하고 있었다. 두번째, 평생교육사 자격이 있는 사서가 없는 경우에 비해 업무를 수월하게 인식하고 있었으며(P=0.04), 단위업무별로는 강사섭외(P=0.04), 운영계획수립(P=0.05)에 있어 유의한 차이가 검증되었다. 또한 평생교육관련 경력이 길수록 업무를 수월하게 (R=-0.217) 느끼는 것으로 나타났으며, 특히, 일정편성(R=-0.33), 진행업무(R=-0.22)에 있어, 통계적으로 유의한 상관성을 보였다. 세번째, 다중회귀분석 결과, 공공도서관 사서들이 평생교육업무 전반에 대하여 느끼는 체감 난이도에 유의한 영향을 주는 단위 직무는 운영계획수립(P=0.04)과 홍보(P=0.05) 업무인 것으로 나타났으며, 그중 운영계획수립(${\beta}=0.233$)이 체감 난이도 형성에 가장 많은 영향을 주는 요인인 것으로 판명되었다. 한편, 91%의 사서가 평생교육 직무 관련 재교육이 필요하다고 느끼고 있으며, 스피어만(Spearman rank-order correlation coefficient) 분석 결과(R=-0.210), 평생교육 업무에 대한 체감 난이도가 높은 사서일수록 재교육 필요성을 더욱 많이 느끼고 있는 것으로 나타났다. AHP 분석 결과 평생교육 직무 관련 재교육 내용은 이용자와의 소통(CU P=0.310), 기획(PL P=0.246), 마케팅(LM P=0.173) 순의 가중치를 보였으며, 도출된 CR(Consistency Ratio) 비율은 0.146으로 계산돼, 응답에 대한 일관성은 허용할 수 있는 수준인 것으로 나타났다.

• 여성건강간호학회지
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• 제14권1호
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• pp.12-19
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• 2008

Purpose: This study was to identify the influencing factors in postmenopausal women's bone mineral density (BMD). Method: The sample for the study was 107 postmenopausal women who took the BMD test. For BMD measurement, lumbar spine BMD(L2-5) was measured by Dual-energy X-ray absorptiometry(DEXA). Data was collected by questionnaires on the selected variables such as reproductive factors and life style factors. Result: In reproductive factors, parity shows significant differences with BMD (F=4.16, p=.02). In life style factors, diet (F=3.01, p=.05) and exercise (F=7.39, p=.00) show significant differences with BMD. Excercise, diet and parity accounted for 42.0% of the influencing factors in Postmenopausal Women's Bone Mineral Density. Conclusion: The influencing factors in postmenopausal women's bone mineral density were excercise, diet and parity. In this paper, it is suggested that the influence of reproductive and life style factors in postmenopausal women's BMD should be studied by long term and needs repeated research. This study can be used as foundation material for nursing education program development for osteoporosis prevention and improvement.

• 지역사회간호학회지
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• 제20권1호
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• pp.12-22
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• 2009

Purpose: This study was done to investigate factors associated with depression and quality of life (QoL) among the community-dwelling elderly. Methods: This study used a descriptive correlational research design. The subjects were 730 elders aged over 65 living in D district of Daegu. Data were collected using questionnaires for 30 days in April, 2007. The research instruments utilized in this study were a physical function scale of long-term care insurance system, Geriatric Depression Scale Short Form Korea Version (GDSSF-K), and Korean Quality of Life Scale (KoQoLs). The collected data were analyzed by descriptive statistics, t-test, ANOVA, Duncan, stepwise multiple regression, and Spearman correlation. Results: The mean age of the subjects was 72.6, and 68.8% and 57.9% of subjects were, respectively, female and living alone. 12.3% of variance in depression was explained by age, education, economic status, subjective health, alcohol consumption, condition of teeth, and fall experience. 18.2% of variance in QoL was explained by economic status, number of diseases, condition of teeth, incontinence, paralysis, and IADL. Economic status and condition of teeth were contributing factors to depression and QoL of the elderly. Conclusion: Findings of this study may be useful in understanding the health status of the community-dwelling elderly and developing more regionally specific health promotion strategies.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제29회 춘계학술대회
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• pp.119-126
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• 1999

The rolling fatigue lives (RFL) of five kinds of silicon nitride balls were investigated. Four kinds of Si$_3$N$_4$ balls were fabricated using different raw materials, sintering aids and sintering conditions, Commercially available Si3N4 ball was also studied for comparison. All the balls were finished up to the dimensional accuracy of Grade 10 defined in KS B 2001 (Steel Balls for Ball Bearings) with a size of 9.525mm. RFL tests were then conducted under the initial theoretical maximum contact stress 6.38 GPa and the spindle speed 10,000 rpm. Gear oil was provided by oiled race as lubricant. The results of RFL test indicated the prerequisitic conditions for the long rolling life of Si$_3$N$_4$ball : (1) the high density, (2) mjcrostructures consisted of small uniformly distributed grains, (3) little glassy phase in grainboundary, and (4) little crystalline phase and secondary phase that induces residual thermal stress due to the differences of thermal expansion coefficient with Si$_3$N$_4$Phase.

• International Journal of Advanced Culture Technology
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• 제8권1호
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• pp.218-225
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• 2020

Purpose Wearable devices are widely used in our daily life. The purpose of this study is to investigate the relationship between persuasive designs of fitness trackers and users' physical activity behavior. Methods To test the research model, data was collected from a web-based survey in China, resulting in an effective sample of 166 usable questionnaires. The survey was restricted only to respondents who wear a fitness tracker. Results The sample surveyed in this study indicated that half of the respondents had been wearing a smart fitness tracker shorter than one year, and only 27% were long-time users (longer than two years). Dialogue support and social support strategies were both proved to be effective in increasing users' workout behavior intention. Social support strategies had a greater effect on behavior change than dialogue support strategies. Conclusion The findings from this study make several contributions to the practice. Wearable devices developers can employ the result from this study to help them design devices, which can persuade people to do more exercises and preserve a healthier life.

• Journal of the Korean Data and Information Science Society
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• 제13권2호
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• pp.87-95
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• 2002

In this paper we consider optimal designs of partially accelerated life testing which is devised for multi-component mixed systems with the considerably long lifetime. Test items are run at both use condition and accelerated condition until a specified censoring time. The optimal criterion for the sample-proportion allocated to accelerated condition is to minimize asymptotic variance of the maximum likelihood estimators of the acceleration factor and hazard rates.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제14권2호
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• pp.122-129
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• 2011

The persistence of jaundice beyond the first 2 weeks of life require further investigation and this can be determined if the conjugated bilirubin levels are greater than 1.5 mg/dL or greater than 20% of the total bilirubin level. There is a diverse differential diagnosis for the cause of neonatal cholestasis due to hepatobiliary disease including biliary atresia, which eventually leads to liver cirrhosis if uncorrected before 60~80 days of life. Long-established initial studies include abdominal ultrasonography, hepatobiliary scintigraphy and liver biopsy, but better diagnostic methods are needed. Promising new options are described including MRCP (magnetic resonance cholangiography), ERCP (endoscopic retrograde cholangiography), and PCC (percutaneous cholecysto-cholangiography). Though no single test can differentiate biliary atresia from other neonatal cholestasis with confidence, a combination of diagnostic methods is usually consistently beneficial. By excluding biliary atresia as early as possible, the risk of unnecessary explolaparotomy with intraoperative cholangiography is decreased. Further evaluation would be required for the diagnosis of neonatal cholestasis after excluding biliary atresia.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2006년도 춘계학술발표대회 논문집
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• pp.165-168
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• 2006

This study beings from solving problems of permanent rental housing with environmentally-friendly planning factors to raise quality of life. Environmentally-friendly planning factors of permanent rental housing are derived from the study of references and green building certification systems of other countries. Surveys of inhabitants and experts give weights on these factors. Inhabitants do are focussed natural ventilation, life cycle cost, operation and maintenance cost. This reflects their interest in indoor amenity and a burden on the cost. Experts put more weights on pedestrian spaces considering the old and feeble persons and block planning. Besides, T-test pointed out that there are meaningful differences in land use between inhabitants and experts. Though inhabitants' opinion has priority because they are real user, experts' opinion which has the variety and the view in the long term should be reflected.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.309-310
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• 2006

The considerations for remaining life of ACSR (Aluminum Stranded Conductors Steel Reinforced) in transmission lines has become gradually important to hold reliability and stability of power supply. The remaining life of ACSR exposed to the atmosphere for a long period may rely on deterioration caused by environmental indices such as atmospheric corrosion, galvanic corrosion, crevice corrosion and fatigue corrosion. This paper deals with material characteristic of ACSR due to eccentricity at sleeve point. Test samples are ACSR 240[$mm^2$] conductors, which are real transmission lines. As a result, it is obvious that ACSR due to eccentricity may lead to mechanical deterioration.