• Journal of Chest Surgery
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• 제25권2호
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• pp.131-136
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• 1992

The effect of temperature of cardioplegic solution on myocardial preservation was studied using isolated rat heart perfusion technique. Twenty Sprague-Dawley rats, weighing 120~140gm, were pretreated with intraperitoneal injection of heparin sodium[300u/kg] and then the hearts were excised after cervical herniation 30 minutes later. The hearts were perfused in isolated working heart apparatus with oxygenated modified Tyrode solution at 37oC. After 10 minutes of non working heart perfusion, the hearts were subjected to arrest for 30 minutes by administration of 5cc cardioplegic solution at the temperature of 4oC [Group I ], 15oC [Group II], 25oC [Group III], 37oC[Group IV]. At the same time, the topical cooling of heart was performed using ice saline. After arrest, the hearts were reperfused by non working heart perfusion for 1 hour with modified Tyrode solution at 37oC. The CPK, GOT and LDH in reperfusate were measured at 5,20,40,60 minutes after start of reperfusion. With the values of those, we compared the effect of temperature of cardioplegic solution on myocardial preservation. The results were as follows; 1. The enzyme values in reperfusate were highest at 5 minute and after then declined. 2. At 5 minutes after reperfusion, the enzyme values in Group I were lower than those in other Groups. These results suggest that the cardioplegic solutions using for cardiac arrest and myocardial protection can be working better at 4oC than at any other temperature.

• Journal of Astronomy and Space Sciences
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• 제28권1호
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• pp.79-91
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• 2011

Ongnu (Jade Clepsydra; also called Heumgyeonggaknu) is a water clock was made by Jang Yeong-sil in 1438. It is not only an automatic water clock that makes the sound at every hour on the hour by striking bell, drum and gong, but also an astronomical clock that shows the sun's movement over time. Ongnu's power mechanism used is a water-hammering method applied to automatic time-signal device. The appearance of Ongnu is modeled by Gasan (pasted-paper imitation mountain) and Binpungdo (landscape of farming work scene) is drawn at the foot of the mountain. The structure of Ongnu is divided into the top of the mountain, the foot of the mountain and the flatland. There located are sun-movement device, Ongnyeo (jade female immortal; I) and Four gods (shaped of animal-like immortals) at the top of the mountain, Sasin (jack hour) and Musa (warrior) at the foot of the mountain, and Twelve gods, Ongnyeo (II) and Gwanin on the flatland. In this study, we clearly and systematically understood the time-announcing mechanism of each puppet. Also, we showed the working mechanism of the sun-movement device. Finally, we completely established the 3D model of Ongnu based on this study.

• 노동경제논집
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• 제42권2호
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• pp.63-99
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• 2019

본 연구는 2008~2017년 "고용형태별 근로실태조사" 원자료를 사용하여 최저임금 인상이 신규근로자의 고용과 근로시간에 미치는 영향을 추정하였다. 최저임금의 내생성 문제를 완화하고자 성별, 연령, 학력에 따라 근로자 집단을 구성하였다. 최저임금의 인상은 신규고용을 감소시키고 주당 근로시간이 15시간 미만인 초단시간 신규근로자의 비중을 증가시키는 두 가지 부정적인 효과가 있음이 나타났다. 최저임금의 인상에 특히 취약한 계층은 여성, 청년층과 고령층, 고졸 이하 집단으로 나타났다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.375-375
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• 2006

The preparation methods are to be used as "melting method" and "absorption method", respectively. The reaction mixture in the reaction container was heating up the reaction mixture to $200^{\circ}C$ for 2 hour. The mixing time of lab scale preparation should be provided quit long, instead of the short working time in a compounder vessel. And The PP-PCM mixture in the reaction container was heating up the mixture around $60-80^{\circ}C$ for 2 hour. A melting method of frozen gel with 50/50 weight ratio of polypropylene-normal octadecane was prepared by adding PP chip and normal octadecane. An absorption method of frozen gel with 70/30 weight ratio of PP 4.8-normal n-octadecane was prepared by adding PP powder and normal octadecnae.

• 상하수도학회지
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• 제9권3호
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• pp.78-87
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• 1995

A study on the fouling control by periodical ozone-scrubbing was conducted in a membrane filtration process for drinking water treatment. Hydrophilic hollow fiber polyethylene membrane with pore size of $0.1{\mu}m$ and its surface area of $0.42m^2$ was used. Dead-End filtration method was selected to obtain high efficiency of energy. Laboratory prepared synthetic raw water with kaolin was used and the membranes were scrubbed by ozone once in an hour and once in two hours. When the duration of ozone scrubbing was increased from 10 seconds to 20 seconds, the rate of membrane fouling was significantly decreased. Although the frequency of ozone-scrubbing was reduced from once in an hour to once in two hours. the effect of fouling control was unchanged. However, ozone-scrubbing was not effective after a membrane was fouled and washed with detergent for reuse. Among several possible working effects of ozone, bactericidal effect was confirmed to be the primary reason of fouling control.

• 대한간호학회지
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• 제2권1호
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• pp.87-96
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• 1971

This Study was undertaken to evaluate the present health status and fatigue of the workers in T. Industrial Company in Pusan in Jan. 1971. The results were based on a question are from 354 working girls. The results of this study are as follows: 1. The largest portion of the workers, 20.2% of the questioned employees, were observed to lie at age 20. 2. Regarding their formal education, 76.0% of them had completed middle school. while only 7. 1% had graduated from high school, . 3. 63.0% receive 7-8 hrs. of sleep a day while 18.4% receive S-6 hrs. of sleep a day. 4. 36.4% spend leisure time reading: while 15.5% spend it resting and thinking. 5. 53.8% of them live in the company′s dormitory and 31.6% live at home. 6. Time spent in travel to work: 32.8% spent 40-49 min., 23.6% spent 10-29 min. 7. The shift times were reported as: 44.1% wonting from 8 A.M. to 4 P.M. and 33.9% working from 6. A.M. to 2. P.M. which is what they are doing now. 8. Regarding symptoms of fatigue: 1) Physical symptoms were: 48.3% complained of "feeling bean in the legs, ", and 39.3% complained of "general exhaustion. " 2) Psychological symptoms were: 37.6% said that "it is boring to talk"and 26.3% said" they had a desire to be alone". 3) Nitrogenic symptoms were 49.7% complained of "asthenopia"and 37.0% complained of"vertigo and "staggering legs". 9. When asked about the most fatiguing time during work, the following information was reported: 25.2% felt the first hour in the morning was most fatiguing while 22.9% felt the sixth hour in the evening, and 22.8% eelt the fifth hour at night was. 10. 38.4% complained of sleepiness at 3 A.M. and 35.0% at 4 A.M. during night work. 11. 38.1% found Sunday the most fatiguing work day and 20.% found Monday. 12. The results of the effects of their work on certain diseases: 51.1% showed those with anemia as most effected by work. 13. In their Response to the question, "do you eat breakfast\ulcorner"57.0%, the largest portion, answered, " none at all ": 36.3%, enough. 14. Regarding the accident rate relating to the length of time employed at the company 28.5% was the highest accident rate from 5year to 6 year. As a result of this study, it could be concluded that the employer should consider the following points: 1. employ according to the worker′s vocational aptitude. 2. adjust the shifts. 3. offer rest time and off days, and establish recreational facilities. In the end we can contribute to the promotion of the workers of the workers and to the prevention of accidents due to industrial fatigue.

• 한국산림과학회지
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• 제73권1호
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• pp.14-20
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• 1986

일본잎갈나무 일차간벌림(一次間伐林)에서 간벌장재(間伐長材)의 매목별(每木別) 벌목(伐木)-소운반(小運搬)까지 공정(功程)을 알기 위하여 1인(人) 단독(單獨)으로 기계톱벌목(伐木)-도끼가지치기-인력소운반작업(人力小運搬作業) 조직(組織)을 투입(投入)하였다. 작업장소(作業場所)는 임업기계훈련원(林業機械訓練院) 27 임반(林班)에서 영림기능인(營林技能人) 2급자격자(級資格者)에 의거 작업(作業)을 시키고 69 본(本)을 조사(調査)하였다. 동연구(同硏究)의 또 하나의 주요목적(主要目的)은 지역별(地域別) 공정표제작방법(功程表製作方法)을 도입(導入) 보급(普及)시키는데 있었다. 시간(時間)은 25/100분(分) 간격으로 관측을 하였으며 매 싸이클별 작업자(作業者)者의 능률(能率)을 사정하였다. 총 작업시간은 8.11시간(時間)이며 이 중 간벌작업(間伐作業)이 90%, 제벌작업(除伐作業)이 10%을 점하고 있다. 시간유형별(時間類型別)로는 순작업시간(純作業時間)이 82.7%, 일반작업시간(一般作業時間)이 12.3%이고 측정불필요시간(測定不必要時間)이 4.9% 이었다. 간벌(間伐)을 위한 순작업시간(純作業時間)은 5.9시간(時間)이며 이 중 간벌목(間伐木)으로 이동시간(移動時間)이 20.9 %, 벌목(伐木)이 7.1%, 가지치기가 40.5%이고 집재로(集材路)까지의 운반(運搬)이 11.5%이었다. 기계톱의 순작업시간(純作業時間)은 0.94시간(時間)(이 중 제벌작업(除伐作業)이 0.2시간(時間))이며 가동시간(可動時間)이 66%, 공전시간이 34%를 점하고 있었다. 직경급별(直徑級別) 공정(功程)을 얻기 위하여 회귀식(回歸式)을 구하고, 작업원(作業員)의 능률(能率)은 130%로 사정하여 기본시간(基本時間)과 일반시간(一般時間)을 구하였던 바 표(表) 1과 같은 결과를 얻었다. 표(表) 1은 활용시(活用時) 복잡할 것으로 예상하여 공정표(功程表)를 표(表) 2와 같이 제안(提案)하여 실용화(實用化) 되도록 하였다. 작업관리(作業管理)를 합리화(合理化)시키기 위해서는 상기(上記)와 같은 공정표제작방법(功程表製作方法)의 도입(導入)은 바람직한 결과를 주게 될 것이다.

• 한국산업보건학회지
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• 제15권3호
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• pp.250-260
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• 2005

This study was designed to find the symptom prevalence rates of musculoskeletal disorders and the risk factors of musculoskeletal disorders among selected hair dressers. Methods; The survey were conducted from July 1 to 30, 2004 for 459 hair dressers working in Seoul and Gwangju using self-administration questionnaire. The risk factors on musculoskeletal disorders have analysed by multiple linear regression analysis. The results of this study are summarized as follows: The experience rate of musculoskeletal disorders symptom in the last one year was 56.4%. The experience rates of each body parts were 36.4% on the shoulders, 30.5% on the legs and the feet, 28.5% on the low back, 27.0% on the hand and the fingers, 23.3% on the neck and 17.0% on the arms and the elbows. The prevalence rate of musculoskeletal disorders symptom in the last one week was 40.5%, those of each body parts were 24.0% on the legs and the feet, 21.4% on the shoulders, 20.7% on the low back, 15.7% on the hand and the wrists, 15.0% on the neck, 9.4% on the arms. The risk factors on musculoskeletal disorders were working posture(${\beta}=0.32$), perceived stress(${\beta}=0.19$), working period(${\beta}=0.16$), standing working over 10 hour(${\beta}=0.16$), hard working(${\beta}=0.11$). The adjusted determinant coefficient($R^2$) of this regression model was 0.267. Based on the results, in order to prevent musculoskeletal disorders of hair dressers, working posture shall be improved and leisure opportunities to relieve stress, and health management program shall be provided.

• 한국산업보건학회지
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• 제29권3호
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• pp.383-393
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• 2019

Objectives: The proportion of those working beyond 53 hours a week in 2018 has reached 16.8% of the total number of workers in the Republic of Korea (Statistics Korea, 2018). Although there are many studies that have dealt with the correlation of long working hours and increasing risk of work-related health problems, studies dealing with the factors impacting work-related health problems of workers according to their working hours are few. This study aims to ascertain factors impacting work-related health problems of workers based on their working hours through thorough research on their work environment. Methods: Necessary factors for this study were extracted from 'the 4th Korean Working Conditions Survey to analyze details on normal characteristics and work environments used for the study analysis, work hours, and health problems related to work. Results: The results are as follows: First, men showed a greater probability of exposure to work-related health problems than did women, especially in the 50s age group, which showed the highest potential for health problems from work among age groups. Second, service providers and sales professionals showed a higher probability of work-related health problems. Third, for the work environment, health problems at work related to vibration, noise, chemical and poison exposure, exhaustion, pain, standing position, and repeated motion showed a higher probability if the work hours are long. Conclusions: This study suggests that the minimization of overtime labor would prevent work-related health problems and diseases, improve the well-being of workers, and decrease the negative impact on workers in the subject area.

• 임상간호연구
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• 제16권2호
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• pp.57-67
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• 2010

Purpose: The purposes of this study were to compare the level of perception and to identify factors associated with perception on patient safety culture among health care providers working in an operating room(OR). Methods: A cross-sectional survey design was used. Data were collected conveniently from 154 RNs and 116 physicians working in a tertiary hospital in Seoul. Patient safety culture was measured using "The Hospital Survey on Patient Safety Culture" developed by the Agency for Healthcare Research and Quality (AHRQ). Descriptive statistics, t-test, ANOVA, and Spearman rank correlation coefficients were used for statistical analysis with the SPSS version 17.0. Results: The perception level of nurses and physicians on patient safety culture was "moderate" (3.14). Compared to physicians, nurses showed a significantly lower perception on the items of "teamwork within units" (t=-6.904, p<.001) and "overall perception of patient safety" (t=-4.327, p<.001), but had a higher perception about "frequency of events reported" (t=2.769, p=.006). The physicians' professional positions, years of working experience, age, and working hour per week were identified as factors associated with patient safety culture. Conclusion: Level of perception on patient safety culture may vary among health care providers working in the OR. The study finding suggests that a tailored education and training strategies should be considered to develop an effective safety culture for healthcare professionals working in OR.