• 품질경영학회지
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• 제45권4호
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• pp.649-664
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• 2017

Purpose: This paper introduces the technology of prognostics for Industry 4.0 and presents its application procedure for fitness-for-service assessment of natural gas pipelines according to ISO 13374 framework. Methods: Combining data-driven approach with pipe failure models, we present a hybrid scheme for the gas pipeline prognostics. The probability of pipe failure is obtained by using the PCORRC burst pressure model and First Order Second Moment (FOSM) method. A fuzzy inference system is also employed to accommodate uncertainty due to corrosion growth and defect occurrence. Results: With a modified field dataset, the probability of failure on the pipeline is calculated. Then, its residual useful life (RUL) is predicted according to ISO 16708 standard. As a result, the fitness-for-service of the test pipeline is well-confirmed. Conclusion: The framework described in ISO 13374 is applicable to the RUL prediction and the fitness-for-service assessment for gas pipelines. Therefore, the technology of prognostics is helpful for safe and efficient management of gas pipelines in Industry 4.0.

• 운동영양학회지
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• 제25권2호
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• pp.26-32
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• 2021

[Purpose] This study aimed to analyze the prevalence of hypertension according to the body mass index (BMI) and relative handgrip strength (RHGS) among elderly individuals in Korea. [Methods] We analyzed the data of 44,183 Korean elderly individuals over 65 years old (men: n = 15,798, age = 73.31 ± 5.04 years, women: n = 28,385, age = 72.14 ± 5.04 years) obtained from the Korean National Fitness Assessment in 2019. All the participants were categorized into three groups according to the BMI and RHGS; additionally, one-way ANOVA and logistic regression analysis were performed. [Results] Overweight (men: 1.16 odds ratio [OR] 1.06-1.26, 95% confidence interval [CI]; women: 1.15 OR, 1.07-1.23 95% CI) and obese (men: 1.54 OR, 1.42-1.66 95% CI; women: 1.44 OR, 1.36-1.53 95% CI) elderly individuals showed a higher prevalence of hypertension than elderly individuals with normal weight, after controlling for age. In men, a lower RHGS was associated with a higher prevalence of hypertension after controlling for age (weak RHGS: 1.09 OR, 1.00-1.17 95% CI; middle RHGS: 1.21 OR, 1.12-1.31 95% CI vs. strong RHGS). [Conclusion] A higher BMI was associated with the prevalence of hypertension in the elderly Korean population. In addition, a lower RHGS was associated with the prevalence of hypertension in elderly Korean men.

• Nuclear Engineering and Technology
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• 제48권6호
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• pp.1412-1422
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• 2016

Austenitic stainless steels (ASSs) are widely used for nuclear pipes as they exhibit a good combination of mechanical properties and corrosion resistance. However, high tensile residual stresses may occur in ASS welds because postweld heat treatment is not generally conducted in order to avoid sensitization, which causes a stress corrosion crack. In this study, round robin analyses on stress intensity factors (SIFs) were carried out to examine the appropriateness of structural integrity assessment methods for ASS pipe welds with two types of circumferential cracks. Typical stress profiles were generated from finite element analyses by considering residual stresses and normal operating conditions. Then, SIFs of cracked ASS pipes were determined by analytical equations represented in fitness-for-service assessment codes as well as reference finite element analyses. The discrepancies of estimated SIFs among round robin participants were confirmed due to different assessment procedures and relevant considerations, as well as the mistakes of participants. The effects of uncertainty factors on SIFs were deducted from sensitivity analyses and, based on the similarity and conservatism compared with detailed finite element analysis results, the R6 code, taking into account the applied internal pressure and combination of stress components, was recommended as the optimum procedure for SIF estimation.

• Journal of Preventive Medicine and Public Health
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• 제27권3호
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• pp.531-545
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• 1994

In a TV component manufacturing factory, 102 male workers aged $20{\sim}39$ years old were participated in testing for physical fitness. At the same time, worker's periodic health examination was done. Test battery for physical fitness include grip strength, trunk flexion, standing long jump, side step, single leg balance with eye close, push ups and Harvard step test. As a result of testing for physical fitness, synthetically, there is no difference between manufacturing workers and officers. By bioelectrical impedance test, it means a declining tendency to all 7 factors in the obese workers, and so, it is important for obese workers not only to promote physical fitness but also to promote health. Excluding grip strength and single leg balance with eye close, 5 fitness factors are negatively associated with degree of diastolic Blood pressure, but it is statistically not significant. And levels of sGOT & sGPT have no association with physical fitness factors.

• 운동영양학회지
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• 제13권1호
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• pp.69-74
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• 2009

The purpose of this study was to investigate the effects of a winter training camp on physical fitness, physical self-efficacy and nutrients intake in juvenile Taekwondo players. Sixty three subjects of male middle school student Taekwondo players participated in this study. Before and after attending Taekwondo winter training camp, Taekwondo related fitness and physical self efficacy and nutrients intake of subjects were measured and compared. The results of this study were as follows: 1) There were significantly improvements (p<0.001) in 1200m run, sit up, push up. 2) There was no significantly change in physical self efficacy. 3) There were significantly increase intakes (p<0.001) in total calorie, protein, fat, fiber, Ca, P, K, vitamin A, vitamin B2, vitamin B6, niacin, vitamin C and vitamin E. However, index of nutritional quality in fiber, Ca, K, vitamin A had not good assessment. These results suggested that a winter training seems necessary to keep psychological management and scientific dietary management as well as physical training in juvenile Taekwondo players.

• 한국가스학회:학술대회논문집
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• 한국가스학회 2000년도 추계학술발표회 논문집
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• pp.110-115
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• 2000

• 한국해양공학회지
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• 제29권1호
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• pp.100-110
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• 2015

To meet the increasing demand for energy around the world, offshore and subsea energy development is constantly being conducted. This trend is accompanied by an increasing demand for pipeline installation, which brings numerous problems, including those related to accessibility, high pressure, and corrosion. Among these, corrosion is a primary factor in pipeline fractures, and can cause severe environmental and industrial damage. Hence, accurate corrosion assessment for corroded pipelines is very important. For this reason, the present study investigated the mechanical behavior of an idealized corroded subsea pipeline with an internal/external pressure load using the commercial FEA code ABAQUS. Then, the analysis result was compared with corrosion assessment codes such as ASME B31G, DNV RP F101, ABS. Finally, a fitness-for-service assessment was conducted.

• 치위생과학회지
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• 제19권4호
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• pp.238-244
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• 2019

Background: Recently, three-dimensional (3D) printing has been hailed as a disruptive technology in dentistry. Among 3D printers, a digital light processing (DLP) 3D printer has certain advantages, such as high precision and relatively low cost. Therefore, the latest trend in resin crown manufacturing is the use of DLP 3D printers. However, studies on the internal fitness of such resin crowns are insufficient. The recently introduced 3D evaluation method makes it possible to visually evaluate the error of the desired area. The purpose of this study is to evaluate the internal fitness of resin crowns fabricated a by DLP 3D printer using the 3D evaluation method. Methods: The working model was chosen as the maxillary molar implant model. A total of 20 resin crowns were manufactured by dividing these into two groups. One group was manufactured by subtractive manufacturing system (PMMA), while the other group was manufactured by additive manufacturing system, which uses a DLP 3D printer. Resin crowns data were measured using a 3D evaluation program. Internal fitness was calculated by root mean square (RMS). The RMS was calculated using the Geomagic Verify software, and the mean and standard deviation (SD) were measured. For statistical analysis, IBM SPSS Statistics for Windows ver. 22.0 (IBM Corp., USA) was used. Then, independent t-test was performed between the two groups. Results: The mean±SD of the RMS were 41.51±1.51 and 43.09±2.32 for PMMA and DLP, respectively. There was no statistically significant difference between PMMA and DLP. Conclusion: Evaluation of internal fitness of the resin crown made using a DLP 3D printer and subtractive manufacturing system showed no statistically significant differences, and clinically acceptable results were obtained.

• 한국응용과학기술학회지
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• 제38권4호
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• pp.1117-1128
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• 2021

본 연구의 목적은 에너지 소비 및 심폐 능력 향상을 위한 고강도 유산소 운동, 근력 및 근지구력 강화를 위한 서킷 트레이닝, 생활 습관 변화 교육으로 구성된 4주간의 건강증진 중재 프로그램이 과체중 또는 비만 초등학생의 비만도, 체력수준, 인슐린 저항성 및 대사증후군 미치는 영향을 조사하는데 있다. 과체중 또는 비만 아동 23명을 비만군으로, 정상체중 아동 15명을 정상군으로 선발하였다. 건강증진 프로그램은 총 4주간, 주 3일, 1일 2시간의 운동시간과 1시간의 교육으로 구성되었다. 비만도(체질량지수, 허리둘레, 체지방률), 체력(근력, 근지구력, 유연성, 심폐체력), 인슐린 저항성 및 대사증후군 위험요인(혈압, 공복 혈당, 중성지방, 고밀도 지단백 콜레스테롤)을 측정하였다. 프로그램 참여 후, 비만도의 유의미한 감소는 없었지만, 비만 아동의 체력수준, 인슐린 저항성 및 대사 증후군 위험 요인은 상당한 개선이 있었다. 결과적으로 여름캠프 참여를 통해 비만 초등학생의 체력수준 향상, 인슐린 저항성 감소 및 대사증후군 위험요인의 빈도 감소에 효과가 있는 것으로 밝혀졌다.

• 대한지역사회영양학회지
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• 제21권1호
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• pp.37-52
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• 2016

Objectives: This study was performed to develop an assessment tool for middle aged women's health status based on dietary patterns, which will have practical applications in the working field of health and hygiene, aiming at improving the middle aged women's quality of life through their health improvement. Methods: As a first step, a literature review was conducted and the original data of '2008~2009 Korea Health and Nutrition Examination Survey' were reanalyzed. This analysis identified 65 preliminary questions that may be relevant to the study. After verifying the content validity by experts, the 65 questions were reduced into 51 questions. In order to secure higher validity of the candidate items, verification of their clinical validity was conducted among women aged between 45 and 60 years. Finally, an assessment tool was developed by applying weight and scoring. Results: Selected 51 questions were used to verify clinical validity and the results showed that 20 questions were relevant, nine questions ('regular meal time', 'regular amount of meal', 'intake frequency of dairy products', 'intake frequency of fruits', 'intake frequency of meat products', 'intake frequency of high cholesterol foods', 'intake frequency of salty foods', 'appetite', 'eat breakfast everyday') were related to dietary life. Eleven other questions ('self-rated health status', 'deep sleep', 'smoking', 'frequency of drinking', 'stress levels', 'health-related fitness levels', 'pounding of the heart', 'strange feelings on the skin', 'interfere with daily life', 'menopause will bring you a chance to see the life in a different perspective', and 'body mass index') were selected as valid questions. For the response scale for each question, 5 point Likert scale was used to make total 100 point score. Conclusions: This study is the first attempt to develop a health status assessment tool for middle aged women based on their dietary patterns. We conclude that this tool is expected to be a useful and practical tool in the field.