• Safety and Health at Work
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• 제3권4호
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• pp.268-277
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• 2012

Objectives: 1) To determine mercury levels in urine samples from garbage workers in Southern Thailand, and 2) to describe the association between work characteristics, work positions, behavioral factors, and acute symptoms; and levels of mercury in urine samples. Methods: A case-control study was conducted by interviewing 60 workers in 5 hazardous-waste-management factories, and 60 matched non-exposed persons living in the same area of Southern Thailand. Urine samples were collected to determine mercury levels by cold-vapor atomic absorption spectrometer mercury analyzer. Results: The hazardous-waste workers' urinary mercury levels (10.07 ${\mu}g/g$ creatinine) were significantly higher than the control group (1.33 ${\mu}g/g$ creatinine) (p < 0.001). Work position, duration of work, personal protective equipment (PPE), and personal hygiene, were significantly associated with urinary mercury level (p < 0.001). The workers developed acute symptoms - of head-aches, nausea, chest tightness, fatigue, and loss of consciousness at least once a week - and those who developed symptoms had significantly higher urinary mercury levels than those who did not, at p < 0.05. A multiple regression model was constructed. Significant predictors of urinary mercury levels included hours worked per day, days worked per week, duration of work (years), work position, use of PPE (mask, trousers, and gloves), and personal hygiene behavior (ate snacks or drank water at work, washed hands before lunch, and washed hands after work). Conclusion: Changing garbage workers' hygiene habits can reduce urinary mercury levels. Personal hygiene is important, and should be stressed in education programs. Employers should institute engineering controls to reduce urinary mercury levels among garbage workers.

• 디지털콘텐츠학회 논문지
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• 제19권7호
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• pp.1297-1302
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• 2018

이 연구의 목적은 실제 장애인 선수들을 대상으로 시중에 판매되고 있는 High-end급 핸드 사이클과 새로 개발한 핸드사이클의 크랭킹을 비교 분석 하고자 한다. 현재 대한장애인사이클 연맹에 선수로 등록되어 있는 선수중 동일한 지체유형을 가지고 있는 남자선수 10명을 대상으로 하였다. 대상자들의 운동학적 데이터 획득을 위해 12대의 적외선카메라(Oqus-500)를 사용하였다. 자료 획득을 위해 30초 자료 중 15초 전 후의 크랭킹 3회를 분석하였다. 통계적 검정은 SPSS 16을 이용하여 대응표본 t-test를 이용하여 RX와 시제품의 운동역학적 변인의 차이를 검정하였으며, 이때의 유의 수준은 ${\alpha}=.05$로 하였다. 크랭킹 시 근발현이 가장 높게 나타나는 180~195도 구간에 대한 선수들의 근 피로도 감소를 위해 핸드사이클 크랭크를 곡선으로 제작하여 적용할 필요가 있으며, 향후 연구에서는 핸드사이클의 크랭킹이 경기력 향상의 주요변인인 만큼 구조를 변형시킨 크랭크와 기존데이터를 비교 분석할 필요가 있다.

• 한국재료학회지
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• 제8권12호
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• pp.1176-1181
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• 1998

VIM에 의해 제조된 0.55wt.% C-1.68wt.% Mn강을 사용하여 고주파 유도경화 베어링강의 특성을 조사하였다. 시편의 청정도는 DIN 50602에 의한 K4값이 6.41로 측정되어 높게 나타났다. 고주파 유도경화된 시편은 약 2.7mm의 유효경화층 깊이를 가진 표면경화층이 형성되었으며 불균질한 submicron크기의 lath 마르텐사이트가 표면경화층에 형성되었다. 회전접촉 피로 시험은 최대 헤르쯔 응력 492 kgmm$^{-2}$ 을 가하며 탄성유체 윤활조건에서 실시되었다. 회전접촉 피로시험 후 시편의 궤도면 직하에서 측정된 미소경도는 유도경화한 경우에 비해 표면직하 약 $500\mu\textrm{m}$ 깊이까지 증가하였다. 그 경도증가량의 최대치를 나타내는 위치는 표면에서부터 약 100$\mu\textrm{m}$ 깊이로 밝혀졌으며 백색부식영역 (white etching area)을 나타내었다 회전접촉 피로시험 후 시편의 궤도면 직하, 이 백색 부식영역에서 균열이 생성되고 전파하였다.

• 근관절건강학회지
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• 제18권2호
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• pp.270-281
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• 2011

Purpose: This study was done to determine if osteoarthritis (OA) patients living in rural Korea would have a benefit from a structured group program focused on self-help strategies. Methods: A hundred and twenty-six patients with OA were recruited from nine Primary Health Care Posts. The experimental group received a 6-week self-help education program while the control group received usual care. T-tests and c2-tests were used to determine the homogeneity between the experimental and control groups. Independent sample t-tests were performed to determine the effect of the treatment program. To guard against such likelihood, the level of significance of t-test was determined by Bonferroni correction within the study constructs. When significant group differences were found in study variables at baseline, analysis of covariances (ANCOVAs) were used for group comparisons of outcome variables. Results: The experimental group reported more significant improvement in fatigue, difficulty with physical activity, depression, quality of life, self-efficacy, and health behaviors than did the control group. The experimental group also showed improvements in range of motion and muscle strength as compared to the control group. Conclusion: A self-help group education program was an effective and powerful strategy to promote physical and psychosocial health in OA patients

• 대한방사선치료학회지
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• 제6권1호
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• pp.154-170
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• 1994

The Purpose of this study was to determine the degree and contents composing the qualify of life and to analyze the relationships among the demographic characteristics, the degree of pain and the quality of life of the cancer patients experiencing a radiation therapy. The subjects for this study were 110 out-patients experiencing a radation therapy at C University Hospital in K-city, from April to October, 1992. The data were obtained using a convenience sampling technique. The tool of this study was the quality of life scale developed by Ro, You-Ja and the data were analyzed using a SAS program for percentages, mean & standard deviation. ANOVA and Scheffe test. The results were as follows : 1. the average total score of the quality of life of the subjects was 139.65(minimum score 121-maximum score 164), item mean score grange 1-5) was 2.97. For each factor in the quality of life scale, the mean scores (range 1-5) were 3.29 in emotional state, 3.14 in relationship with neighbors. 3.04 in physical state and function. 2.92 in self-esteem, 2.81 in economic life and 2.65 in relationship with family. 2. The incidence of physical symptoms was seen fatigue ($84.5\%$). anorexia ($65.5\%$) and weight loss ($47.3\%$) in order. The 50.9 percentage of the subjects complained of moderate or severe pain. 3. The results of the analysis of the relationships between the demographic variables and the quality of life were as follows : Gender (F=8.45, P=0.0044), age (F=6.29, P=0.0001). educational level (F=5.67, P=0.0046), marital status (F=6.82. P=0.0016), occupation (F=2.86, P=0.009), monthly income (F=6.90, P=0.0003), family living together (F=3.95, P=0.0494) and person paying a medical fee (F=5.14, P=0.0023). 4. The relationship between the degree of pain and the quality of life was significant difference (F=3.12, P=0.0482).

• 대한인간공학회지
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• 제30권5호
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• pp.671-681
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• 2011

Objective: The purpose of this study is to compare the workload level at each lower limbs posture and suggest the ergonomic workstation guideline for working period by evaluating the imbalanced lower limbs postures from the physiological and psychophysical points of view. Background: Many workers like welders are working in various imbalanced lower limbs postures either due to the narrow working conditions or other environmental conditions. Method: Ten male subjects participated in this experiment. Subjects were asked to maintain 3 different lower limbs postures(standing, squatting and bending) with 3 different working conditions(balanced floor with no scaffold, imbalanced floor with 10cm height of scaffold, and imbalanced floor with 20cm height of scaffold). EMG data for the 4 muscle groups(Retus Femoris, Vastus Lateralis, Tibialis Anterior, Gastrocnemius) from each lower limbs posture were collected for 20 seconds every 2 minutes during the 8 minutes sustaining task. Subjects were also asked to report their discomfort ratings of body parts such as waist, upper legs, lower legs, and ankle. Results: The ANOVA results showed that the EMG root mean square(RMS) values and the discomfort ratings(CR-10 Rating Scale) were significantly affected by lower limbs postures and working time(p<0.05). The correlation was analyzed between the EMG data and the discomfort ratings. Also, prediction models for the discomfort rating for each posture were developed using physical condition, working time, and scaffold height. Conclusion: We strongly recommend that one should not work more than 6 minutes in a standing or squatting postures and should not work more than 4 minutes in a bending posture. Application: The results of this study could be used to design and assess working environments and methods. Furthermore, these results could be used to suggest ergonomic guidelines for the lower limbs postures such as squatting and bending in the working fields in order to prevent fatigue and pain in the lower limbs body.

• 한국식품영양과학회지
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• 제43권12호
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• pp.1937-1941
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• 2014

능소화과인 Tabebuia avellanedae인 타히보는 중앙아메리카와 남아메리카의 아열대 우림지역에서 서식하며 이들은 민간 약제로 사용되어 왔다. 본 연구는 타히보 추출물의 라디칼 소거활성에 기초한 항산화 활성과 운동능력 향상 효과에 대한 활성을 검토하였다. 타히보로부터 얻은 두 추출물 타히보 열수 추출물(TAW)과 타히보 80% 에탄올 추출물(TAE)의 운동능력 향상 효과와 총 폴리페놀과 플라보노이드 함량과 항산화 활성을 평가하였다. 운동능력 향상 효과는 TAW가 대조군 대비 2.0배, TAE는 1.8배 증가하였다. 두 추출물의 항산화 활성은 라디칼 소거활성(DPPH와 ABTS)으로 평가하였다. 동일 농도에서 TAE는 TAW와 비교하여 라디칼 소거활성이 높게 났고 TAE의 총 폴리페놀 함량이 항산화 활성과 연관되어 있는 것으로 나타났으며, 이는 운동으로 인한 산화스트레스를 방어함으로써 마우스의 운동능력 향상 효과를 나타낸 것으로 사료된다.

• 한국안전학회지
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• 제33권4호
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• pp.90-97
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• 2018

As the result(also after it's been carried out the damping force test with 800ea lateral dampers of 50ea trainset from entering heavy maintenance workshop to implement heavy maintenance inspection cycle, there were 86.25%(650ea) which were out of $350kg{\pm}15%$ of the standard value of damping force compared to the reference value. After the implementation of heavy maintenance inspection cycle, it's been examined damping force test with total samples 32ea(samples 8ea per a trainset) from actual running EMU 4ea trainset. As the result, percent defective was 84.4%(27ea), which was a very high level. System. The lateral damper's the failure cause of damping force defective was oil leakage caused by tearing crack of oil seal and foreign material in oil iron 473 ~ 1932 times higher than that of new oil, copper 36 ~ 98 times higher than that of new oil reduced oil amount cycling damping valve. It resulted from the change cause of damping force. In the static analysis on the shape of lateral damper oil seal's the existing and improved product, the stress of the improved product was smaller than that of the existing product. In the fatigue analysis, the existing product showed a low life in the upper area. However, in case of the improved product, it could be confirmed that the destruction did not occur up to the specified 1.0e + 006 cycles and the lifetime was further improved in most areas.

• 대한인간공학회지
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• 제33권1호
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• pp.59-68
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• 2014

Objective: The aim of this study is to investigate the effect of BackJoy on how it effectively reduces the physical load generated in a posture in which the user sits, increases user's comfort and satisfaction, and maintains the correct posture. Background: Because of development of science and economic development, most office workers and students spend about 75% of their working time in chairs. However most of them have a poor posture. Method: This experiment conducted measurement using a pressure mat and surveyed to evaluate fatigue level, satisfaction and comfort of sit. The study is experimented 20 male and 14 female participants. The participants carried out four different types of tasks and each task took 20 minutes long. Results: In the case of experiment results before and after the use of BackJoy, average pressure, contact area and pressure per unit area appear to prove that using BackJoy is more effective. Conclusion: Through this study, the BackJoy's effects for the maintenance of good posture and loads that occur in the body are reduced. In the future study, there are some researches needed for various verifications using an EMG sensor that shows loads of vertebrae and we need to analyze each group of the participants by dividing them. Application: The evaluation method used in this study can be applied to evaluating ergonomic chairs.

• 대한인간공학회지
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• 제32권4호
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• pp.333-340
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• 2013

Objective: The aim of this study is to provide a current knowledge of the multiple issues regarding motion effects on crew performance. Background: The motions of the ship may create motion sickness, nausea and vomit. Also, these motions also disturb the balance of crew members, increase the energy expenditure of crew for shipboard work, and result in increased levels of injury and fatigue. However, the motion effects of the ship on crew performance has not been thoroughly investigated. Method: Participants(N=10) were engaged in an experiment in 2 experimental environments(training ship and ship handling simulator) and 2 navigational conditions(day and night). The COP(Center of Pressure) data were recorded as an objective measure of postural balance control and the SSQ(Simulator Sickness Questionnaire) was used as a subjective measure of sickness. Results: The results showed that COP has a no significant difference based on experimental environments, but significant effect on SSQ. Conclusion: During the virtual simulator navigation, subjects showed significant SSQ level changes, which included decreased SSQ data. But, there is no significant difference of COP between training ship and ship handling simulator. Application: The results of this study could be applied to the next generation of ship design to decrease effect of motion at sea and to increase performance of ship crew.