• 설비공학논문집
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• 제12권7호
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• pp.659-666
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• 2000

Heat transfer characteristics of a heat exchanger for low temperature waste heat recovery using oscillating capillary tube heat pipe were evaluated against the charge ratio variation of working fluid and various working fluids. R-l42b, R-22 and R-290 were used as working fluids. The heat exchanger was composed of heat pipe with capillary tube bundles, having a 2.6mm in outer diameter, 1.4mm in inner diameter with 101m long, and 40 turns. Charge ratio of working fluid was 40% and 50%. Water was used as secondary fluid. Inlet temperature and mass velocity for each secondary fluid were 297 K, 280 K and9~27 kg /$m^2s$,, respectively. From experimental results, it was found that heat transfer performance of R-22 was higher than those of R-l42b and R-290 and it was proportional to Figure of merit for thermosyphons. As a result, it was thought that R-22 was the most suitable working fluid of waste heat recovery for low temperature waste heat recovery.

• Journal of Preventive Medicine and Public Health
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• 제26권1호
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• pp.20-36
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• 1993

Work-related low back pain is one of the major factors that cause the loss of working power especially in actively working age, therefore controlling the work-related low back pain is one of the major issues in the field of industrial safety and health. This study was performed for detecting the risk factors and proposing the efficient control program of the work-related low back pain. The subjects were male workers employed at the manufacturing industry in Pusan with longer than 6 months' working duration. The data was collected by self-reported questionnaire and interview from May 1 to October 31,1992. The contents of questionnaire were as follows:. the experience of low back pain within the recent one month, general characteristics(age, marital status, education level, religion, regular exercise), physical characteristics(height, weight), employment status(working duration, daily working hours, rest during work, satis(action fur the job), type of work and working environments(posture, forward bending, lifting and movement, satisfaction for table and chair). The result was analyzed for 608 entire respondents by case-control comparative method. The number of cases was 152 with a history of work-related low back pain, so the relative frequency of self-reported work-related low back pain was 25.0%, and the number of controls was 344 without any history of low back pain. As a result, two characteristics of the employment status(working duration, satisfaction fur the job) and all characteristics of type of work and working environments showed a statistical significance between the case and control groups(p<0.01). The Oddb ratios of these variables for Work-related low back pain were calculated. They were 7.88 for the satisfaction fur chair, 7.86 for lifting and movement,3.31 for satisfaction for table, and 2.22 fur bending forward(p<0.01). And for the multivariate logistic regression analysis confirmed that unsatisfaction for table was independent risk factor for Work-related low back pain. In summary, though this study was based upon the self-reported questionnaire and the subjective complaints, the satisfaction for chair, lifting and movement, satisfaction for table, and bending forward concerned with the type of work and working environments were considered as the main factors causing the work-related low back pain, and the work-related low back pain may be preventable by the ergonomic control of these factors.

• 사회복지연구
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• 제40권3호
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• pp.149-179
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• 2009

본 연구의 목적은 근로빈곤가구의 주거 상향이동에 영향을 미치는 요인이 무엇인지를 파악하는 것이다. 분석결과를 살펴보면, 연령, 교육수준, 근로능력정도, 가구형태, 아동여부, 재산, 수급형태, 지역, 주거위치, 최저시설기준, 주거환경, 대중교통, 교육시설, 영구임대, 국민임대, 전제자금, 월세지원, 대출연체횟수, 부채 요인이 주거상향이동에 영향을 미치는 것으로 나타났다. 분석결과 따른 주요 함의는 다음과 같다. 첫째, 주거지원정책 수립 시 사회복지 측면에서 접근이 이루어져 수급대상의 가구특성 및 개인특성이 충분히 고려되어야 하고, 이를 위해 주거비 지불능력을 제고시킬 수 있는 임대료보조제도가 실시되어야 할 것이다. 둘째, 근로빈곤가구의 주택대출을 위한 금융권의 접근성을 높여야 할 것이다. 마지막으로 정부에서 실시하는 다양한 주거지원정책에 대한 충분한 홍보와 이용률을 높일 수 있는 노력들이 수반 되어야만 근로빈곤가구의 주거빈곤 문제가 해결될 것이다.

• Annals of Occupational and Environmental Medicine
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• 제34권
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• pp.36.1-36.12
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• 2022

Background: Many studies have been conducted to investigate the harmful effect of shift work on physical and mental health. Although, by definition, "working evening shift" is included in the scope of shift work, most related studies conducted thus far have focused on working night shifts, overtime work, or different types of shift work, with little research effort dedicated to "working evening shifts." Therefore, to fill this research gap, we investigated the effect of working evening shifts on workers' mental health. Methods: The participants of this study were 16,692 employees of the 50,205 that participated in the 5th wave of the Korean Working Conditions Survey. We performed χ² test and logistic regression analysis to analyze the effects of independent variables on health problems and calculated odds ratios and 95% confidence intervals (CIs). Results: In the logistic regression analysis adjusted for sociodemographic characteristics, health-related factors, and work-related characteristics, employees who worked evening shifts showed higher levels of depression and anxiety compared to those that did not. In particular, the adjusted odds ratios of the group working evening shifts between one and nine times a month were the highest with 2.723 (95% CI: 2.014-3.682) for depression, 3.294 (95% CI: 2.547-4.259) for anxiety. Conclusions: The results of our study suggest that working evening shifts has a negative effect on employees' mental health. This trend decreased with an increase in the monthly frequency of evening work.

• 한국사회복지학
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• 제57권2호
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• pp.119-142
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• 2005

이 연구는 근로빈곤층의 특성에 맞는 개념정의의 방법을 제안하고, 그러한 개념정의에 따를 때 근로빈곤층의 실태가 어떠한가를 규명하고자 하였다. 이는 근로빈곤층에 대한 개념정의의 방식에 따라 근로빈곤층의 특성은 상이하게 나타날 뿐 아니라, 근로빈곤층을 초점으로 하는 빈곤정책의 방향 또한 달라질 수 있다는 인식 때문이다. 이 연구에서 제안하는 개념정의에 따르면, 근로빈곤층은 '빈곤한 가구의 가구원 중 조사시점에서 지난 6개월 이내에 노동시장에서 일하거나, 구직활동을 수행한 경험이 있는 사람'이다. 이러한 개념정의는 비록 근로능력이 있지만 아동 양육 등의 활동 때문에 비경제활동인구로 존재하는 사람들을 제외시킬 수 있고, 비정규직 임금근로자나 영세자영자 등 다양한 경제활동을 하고 있는 사람들을 배제하지 않을 수 있으며, 불안정한 노동시장 지위로 인해 경제활동인구와 비경제활동인구를 넘나드는 사람들을 포함할 수 있다. 이 연구의 개념정의 방식을 따를 때, 근로빈곤층은 일반적인 생각과는 달리 남성이 여성보다 약간 더 많고, 30세$\sim$60세까지의 사람들이 60% 정도를 차지한다. 하지만 중졸 이하의 학력을 가진 사람들이 절반 가까이 된다는 점은 선행 연구들의 보고와 유사한 것이다. 근로빈곤층의 절대 다수는 어떠한 형태로든 일을 하고 있는 것으로 나타났다는 점 또한 주목할 필요가 있다. 경제활동상태별로 보면 상용직과 자영자의 비중이, 직종별로 보면 판매서비스직과 농어업직의 비중이, 산업별로는 기타서비스업과 농림수산업의 비중이 높았다. 하지만, 보다 장기적인 시점에서 파악한 근로빈곤층의 경제활동상태별 분포에서는 일용직의 비중이 상용직의 비중보다 높았다. 또한 근로빈곤층의 고용상태는 외환위기 이후 지속적으로 악화되어 왔음을 확인할 수 있었다.

• 대한기계학회논문집
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• 제15권2호
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• pp.488-496
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• 1991

Dynamic chanracterisitcs and control of a submerged working robot manipulator have been investigated for articulated type robot manipulator with three revoluted joints. A dynamic equation of the manipulator has been derived. The dynamic equation includes not only mass matrix, centrifugal and Coriolis terms and gravity terms but also added mass, buoyant force and drag force terms, which are important terms for underwater motion description. A series of simulations using computed torque method have been performed for the cases of straight and circular trajectory motion controls. The results of this study show that the dynamic characteristics of the submerged working robot manipulator are very different from that of the manipulator which works in air. The influences of added mass, buoyant force and drag force terms to the total required torques have been discussed as distribution ratios to the total required torques.

• 한국초전도ㆍ저온공학회논문지
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• 제13권3호
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• pp.31-35
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• 2011

This paper describes experimental study on GM-type pulse tube refrigerator with neon as a working fluid instead of helium. Neon gas has similar compression characteristics with helium gas because it is a monoatoimc gas. In experiments, a cooling performance test was performed with same compressor and pulse tube refrigerator for neon and helium as working gas. From experimental results, a PTR with neon show the improved cooling performance than a PTR with helium. Cooling performance and operating characteristics of a PTR were discussed and compared for two different working gas.

• 대한가정학회지
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• 제35권3호
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• pp.139-150
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• 1997

The purpose of this study was (1) to explore the difference in parental satisfaction regarding personal/family, work, and psychological variables of employment characteristics, and (2) to investigate the most effecting variables on the parental satisfaction. For this study, the working mother with children aged under 10 year were surveyed. The results of this study were as follow; (1) There were significant differences in the parental satisfaction according to work time, job preference, income, the difficulty of work life. However, working mother's personal and family variable were not found as the related variable. Psychological variables were correlated with parental satisfaction. (2) Maternal role efficiency, dual role conflict, flexibility of work, marriage year, income, psychological stress, expanded family, durations of occupation, spouse support significantly predicted parental satisfaction. Psychological variables were important in parental satisfaction of working mothers.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.309-314
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• 2008

increased heat dissipation and higher heat density of electronic equipment and/or parts released. A loop heat pipe(LHP) has been payed closer attention to the potential candidate of an electronic cooling. As of the LHP with a circular plate type evaporator developed, this study focused on its operating characteristics on the steady state in accordance with charging different working fluid. The relationship between working fluid and operating characteristics is discussed.

• 한국실내디자인학회논문집
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• 제16권3호
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• pp.85-92
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• 2007

Changing of paradigm at 21Century is changing a part of routine lives and it affects speculation system of recognizing the world. In this society, human is demanded changing of a part and new learning continuously. Like this, a role of individual and a part of various lives by changing of social environment have a close connection each other. In this society, they would need new circumstance of space by method of work. However, what show not necessity improving of work space but changing is the realities of our society. This thesis examine non-territorialization characteristics by focusing on the openness, composition, and flexibility. The working space on 21c head for a non-territorialization and be summarize. decenterial arrangement, increasing of public space and unification of personal work-station. The purpose of this study is to examine the non-territorialization by analysis of 21c working space.