• 제목/요약/키워드: self maintenance

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탄소섬유 분말 혼입 모르타르 복합 구조체의 파괴예측 자가진단 특성 (Self-Diagnosis Property of Fracture in Carbon Fiber Composite Mortar)

  • 박석균
    • 한국구조물진단유지관리공학회 논문집
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    • 제11권1호
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    • pp.113-120
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    • 2007
  • 새로운 재료의 적용 실험을 통하여, 탄소섬유 분말 혼입 모르타르 복합 구조체의 파괴예측 자가진단 적용 특성에 대해 검토하였다. 본 연구에서는 자가진단 성능을 부여하기 위해 코크스와 탄소섬유분말(미분쇄 탄소섬유)이 혼입된 전도성 모르타르의 개발 및 자가진단 재료로서의 사용이 제안되었다. 각 하중재하단계에서의 균열발생 전후의 전기저항값과 AE특성치의 변화특성 시험을 통해, 이들 각 인자의 상호 연관성을 검토하였다. 그 결과, 코크스와 탄소섬유분말(미분쇄 탄소섬유)을 사용하여 새롭게 제안된 복합재료는 모르타르 시험체의 파괴 자가진단에 사용이 가능함을 알 수 있었다.

운용환경을 고려한 항공오일시험장비의 최적정비주기 설정 (Optimal Maintenance Cycle for Aviation Oil Testing Equipment under the Consideration of Operational Environment)

  • 김인석;정원
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제16권3호
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    • pp.224-230
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    • 2016
  • Purpose: Military maintenance involves corrective and preventive actions carried out to keep a system in or restore it to a predetermined condition. This research develops an optimal maintenance cycle for aviation oil testing equipment with acceptable reliability level and minimum maintenance cost. Methods: The optimal maintenance policy in this research aims to satisfy the desired reliability level at the lowest cost. We assume that the failure process of equipment follows the power law non-homogeneous Poisson process model and the maintenance system is a minimal repair policy. Estimation and other statistical procedures (trend test and goodness of fit test) are given for this model. Results: With time varying failure rate, we developed reliability-based maintenance cost optimization model. This model will reduce the ownership cost through adopting a proactive reliability focused maintenance system. Conclusion: Based on the analysis, it is recommended to increase the current maintenance cycle by three times which is 0.5 year to 1.5 years. Because of the system's built-in self-checking features, it is not expected to have any problems of preventative maintenance cycle.

비만치료에 있어서 감량 후 체중 유지에 영향을 주는 요인에 관한 고찰 (Review on Predictors of Weight Loss Maintenance after Successful Weight Loss in Obesity Treatment)

  • 권유경;김서영;임영우;박영배
    • 한방비만학회지
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    • 제19권2호
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    • pp.119-136
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    • 2019
  • Objectives: People often fail to maintain their weight even though they have succeeded in weight loss. The purpose of this study was to review previously published study results with regards to the predictive factors associated with weight loss maintenance after successful weight loss. Methods: The authors searched for the articles related to weight loss maintenance after successful weight loss, published up until June 2019 on PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, Research Information Sharing Service (RISS), and Koreanstudies Information Service System (KISS). A total of 76 articles were finally selected. From the study results, changeable and unchangeable predictors were extracted, and these predictors were examined according to detailed categories. Results: The changeable predictors of weight loss maintenance included behavioral factors, psychological factors and treatment process-related factors, whereas the unchangeable predictors included genetic and physiological factors, demographic factors, history of treatment on obesity-related factors. The main factors of weight loss maintenance were changeable predictors such as healthy eating habits, dietary intake control, binge eating control, regular exercise and physical activity, depression and stress control, social supports, self-regulation, self-weighing and initial weight loss and unchangeable predictors such as low initial weight and maximum lifetime weight. Conclusions: The results of our review results suggest that changeable and unchangeable predictors of weight loss maintenance should be carefully examined during treatments of obesity.

특정소방대상물의 공기호흡기 안전규제 개선방안 (Improving the Safety Regulation For Self Contained Breathing Apparatus)

  • 이상팔
    • 한국화재소방학회논문지
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    • 제24권3호
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    • pp.45-51
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    • 2010
  • 본 논문은 공기호흡기 사용실패 유형과 원인을 생산자에 대한 정부규제와 고객에 대한 정부규제의 문제점을 중심으로 분석한다. 전자의 경우 용기 및 공기호흡기의 안전검사 기준의 한계점 분석이고, 후자의 경우 사용자관리자의 유지관리 및 폐기처분 규정의 한계점 분석이다. 개선방안으로는 수거검사와 수집검사를 확대, 폐용기 처리 결과 감시확인 절차의 투명성 강화 등이 있다.

야간전문대 여학생들의 건강증진 생활양식 -간호계 학생과 비간호계 학생비교- (A comparative study on health promoting lifestyles between Nursing and Non - Nursing students at an evening class of junior college)

  • 정현숙
    • 지역사회간호학회지
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    • 제8권2호
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    • pp.368-380
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    • 1997
  • This descriptive comparative study was conducted to compare the relationships among self-esteem, self-efficacy, perceived health status and the performance of health promoting lifestyles for nursing and non-nursing students. The sample consisted of 246 nursing students and 166 non-nursing students at an evening class of junior college in T city. The data was collected by a self reporting questionnaire from March 2 to March 17, 1997 and analyzed by SPSS Win. 7.0 program for frequency, mean, percentage, t -test, ANOVA, and a Pearson correlation coefficient. The results of this study are summarized as follows: 1. The results of the comparison between the two groups was not significantly different for self esteem and perceived health status, but significantly different for self-efficacy. Nursing students had higher scores on self -efficacy than non-nursing students(t=4.621. p<.05). 2. There was a statistically significant difference between the two groups concerning a health promoting lifestyle. Nursing students ($157.73{\pm}20.26$) had higher scores on total health promotion as well as its 8 subscales than non -nursing students ($048.15{\pm}21.51$,), (t=21.074, p<.001). On subscales, nursing students had the highest score in sanitary life(3.22) and the lowest score in professional health maintenance(1.54). Non -nursing students had the highest score in harmonious relationships(3.10) and the lowest score in professional health maintenance (1.48). 3. Performance in a health promoting lifestyle was significantly correlated with such demographic variables as age and grade for nursing students, and types of dwelling for non -nursing students. 4. Perceptions of good health have been positively correlated with health promoting lifestyles. Those persons who rated their health as good showed the highest score, followed by excellent ,average, poor in that order. 5. Performance in health promoting lifestyles was significantly correlated with self-esteem, self-efficacy and, perceived health status. The most important factor that affect performance in health promoting lifestyles was self -efficacy.

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자기치유 재료 혼입 모르타르 보의 자기치유 성능 평가 (Evaluation of Self-Healing Performance for Mortar Beams Containing Self-Healing Materials)

  • 신동익;무하마드 하룬;민경성;이광명;이정윤
    • 한국구조물진단유지관리공학회 논문집
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    • 제24권1호
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    • pp.67-73
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    • 2020
  • 본 연구에서는 실험을 통하여 자기치유 재료 혼입 모르타르 보의 자기치유 성능을 평가하였다. 실험에는 일반 모르타르 보 실험체와 자기치유 모르타르 보 실험체가 사용되었으며, 모르타르의 압축강도, 내력 및 균열의 자기치유 효과를 비교하여 자기치유 성능을 평가하였다. 실험결과 자기치유 재료를 혼입한 모르타르의 압축강도가 일반 모르타르의 압축강도보다 작았지만 28일 압축강도에 대한 118일 압축강도 비율은 동일하게 나타났다. 실험체의 내력은 재령일이 길어질수록 증가하는 경향을 나타냈다. 일반 모르타르 실험체는 균열이 발생할 경우 재령일이 증가하여도 하중은 회복되지 않았으나 자기치유 모르타르 실험체의 경우 반응 생성물의 영향으로 내력이 다소 회복되는 경향을 나타냈다. 균열폭은 두 종류의 실험체 모두 치유기간이 지난 후 감소하는 경향을 보였으나 자기치유 모르타르 실험체에서만 반응생성물이 관찰되었다.

자기감지형 보수재로 단면증타된 콘크리트 부재의 역학 및 전기적 특성 (Mechanical and Electrical Characteristics of Concrete Members Enlarged with Self-Sensing Cementitious Materials for Repair)

  • 이건철;임건우;임창민;홍성원;김영민
    • 한국구조물진단유지관리공학회 논문집
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    • 제27권5호
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    • pp.139-146
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    • 2023
  • In this study, compressive strength and adhesion strength were measured as repair materials to evaluate the mechanical and electrical properties of compression and shear specimens with self-sensing repair materials. As a result of the experiment, the strength improvement rate of the compression test specimen was higher than the section enlargement area ratio, but the shear test specimen did not show an improvement in strength as much as the section enlargement area ratio. Compression experiments under load showed high correlation between FCR-Strain and FCR-Stress, confirming self-sensing performance. However, the shear test did not show as much correlation as the compression test. Accordingly, it is judged that the self-sensing repair material is suitable for the compression member on which the compression load acts in the building.

해상풍력발전 지지구조물의 유지보수용 수중 기둥등반로봇에 관한 실험적 연구 (Experimental Study on an Underwater Pole Climb Robot for the Maintenance of Offshore Wind Turbine Substructures)

  • 임은철;고진환
    • 로봇학회논문지
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    • 제17권2호
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    • pp.238-244
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    • 2022
  • Maintenance works of offshore wind turbines could take a longer time, which causes the reduction of their energy production efficiency, than those of onshore wind turbines owing to severe offshore environment. Subsequently, preventive maintenance measures are required to increase the production efficiency. Thus, we proposed a wheel-based Underwater Pole Climbing Robot (UPCR) platform, which was aimed at the periodic inspection and maintenance of the substructures of the offshore wind turbines, with three advantages: high speed, good mobility and low power consumption. In the proposed platform, a self-locking system using a gripper module was adopted for preventing slippery problem and a dual configuration was chosen for moving on a branched structure. As a result, the proposed robot was able to continuously climb, preserve it's position at the pole without consuming energy, and move from the pole to the other branched pole. The results of this research show that the UPCR has basic moving capabilities required for the underwater work for the substructures of the offshore wind turbines.

Variables influencing older people's participation in exercise - Based on Transtheorethical Model (TM) -

  • Cho, Young-Suk
    • 보건교육건강증진학회지
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    • 제19권4호
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    • pp.61-76
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    • 2002
  • The purpose of this study is to identify differences in processes of change, decision making, and self-efficacy by exercise behavioral stages and determine variables significantly affecting the older people's participation in exercises. The subjects of this study included 299 people aged 65 or over who were residents of G and S districts in Busan Metropolitan City. They were selected through purposive quota sampling at colleges and centers for old people and homes in order that they could be evenly distributed over stages of pre-contemplation, contemplation, preparation, action and maintenance. Data were analyzed using descriptive, ANOVA, Logistic Regression. Variables that discriminate between participants and non-participants in exercise include self-reevaluation, reinforcing management, cons and self-efficacy. Thus if variables that discriminate between participant and non-participation in exercise such as self-reevaluation, reinforcing management, cons and self-efficacy are fully considered in designing nursing interventions for inducing old people to become exercise participants, it would provide guidelines for nursing intervention programs as appropriate for the people's exercise stages. The purpose of this study is to identify differences in processes of change, decision making, and self-efficacy by exercise behavioral stages and determine variables significantly affecting the older people's participation in exercises. The subjects of this study included 299 people aged 65 or over who were residents of G and S districts in Busan Metropolitan City. They were selected through purposive quota sampling at colleges and centers for old people and homes in order that they could be evenly distributed over stages of pre-contemplation, contemplation, preparation, action and maintenance. Data were analyzed using descriptive, ANOVA, Logistic Regression. Variables that discriminate between participants and non-participants in exercise include self-reevaluation, reinforcing management, cons and self-efficacy. Thus if variables that discriminate between participation and non-participation in exercise such as self-reevaluation, reinforcing management, cons and self-efficacy are fully considered in designing nursing interventions for inducing old people to become exercise participants, it would provide guidelines for nursing intervention programs as appropriate for the people's exercise stages.

만성 관절염 환자의 운동행위 변화단계에 따른 관련변인에 관한 연구 (A Study on the Stage of Change of Exercise Behavior and Related Factors in Patients with Chronic Arthritis)

  • 이윤정;임난영
    • 기본간호학회지
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    • 제13권3호
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    • pp.409-418
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    • 2006
  • Purpose: This study was done to identify the process of change, decisional balance and self-efficacy corresponding to stage of exercise behavior based on the Transtheoretical model in patients with chronic arthritis. Method: The participants were 151 patients with chronic arthritis using an out-patient pain clinic and hospital in C city. The collected data were analyzed using ANOVA, Sheffe test and discriminant analysis with SPSS/WIN. Results: The patients were distributed as follows for each stage of exercise behavior 21.8% in the precontemplation stage, 26.5% in the contemplation stage, 25.2% in the preparation stage, 7.3% in the action stage, and 19.2% in the maintenance stage. Significant effects for stage of change were found for nine of the 10 processes of change and Pros, Cons, self-efficacy. Scores on these variables were found to increase across the stage of exercise behaviors from precontemplation to maintenance. Discriminant analysis revealed that self-efficacy and stimulus control, and reinforcement management were the major correlates of the stage of exercise behaviors. Conclusion: The findings of this study give useful information for exercise intervention, by using strategies of exercise for chronic arthritis patients in different stages of exercise behavior.

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