• Safety and Health at Work
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• 제11권2호
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• pp.178-186
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• 2020

Background: Cognitive impairment is a public health burden. Our objective was to investigate associations between work hours and cognitive function. Methods: Multi-Ethnic Study of Atherosclerosis (MESA) participants (n = 2,497; 50.7% men; age range 44-84 years) reported hours per week worked in all jobs in Exams 1 (2000-2002), 2 (2002-2004), 3 (2004-2005), and 5 (2010-2011). Cognitive function was assessed (Exam 5) using the Cognitive Abilities Screening Instrument (version 2), a measure of global cognitive functioning; the Digit Symbol Coding, a measure of processing speed; and the Digit Span test, a measure of attention and working memory. We used a prospective approach and linear regression to assess associations for every 10 hours of work. Results: Among all participants, associations of hours worked with cognitive function of any type were not statistically significant. In occupation-stratified analyses (interaction p = 0.051), longer work hours were associated with poorer global cognitive function among Sales/Office and blue-collar workers, after adjustment for age, sex, physical activity, body mass index, race/ethnicity, educational level, annual income, history of heart attack, diabetes, apolipoprotein E-epsilon 4 allele (ApoE4) status, birth-place, number of years in the United States, language spoken at MESA Exam 1, and work hours at Exam 5 (β = -0.55, 95% CI = -0.99, -0.09) and (β = -0.80, -1.51, -0.09), respectively. In occupation-stratified analyses (interaction p = 0.040), we also observed an inverse association with processing speed among blue-collar workers (adjusted β = -0.80, -1.52, -0.07). Sex, race/ethnicity, and ApoE4 did not significantly modify associations between work hours and cognitive function. Conclusion: Weak inverse associations were observed between work hours and cognitive function among Sales/Office and blue-collar workers.

• 한국산업보건학회지
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• 제29권3호
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• pp.420-429
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• 2019

Objectives: The purpose of this study was to test the prescribed mediating effect of a sense of job oppression by considering the relationship between emotional labor and work satisfaction. Methods: This study was carried out using the data published in 2016 by the Korea Labor & Society Institute in An Investigation of Quality of Life and the Working Environment in the Service Industry. The data were collected from 638 workers at department stores. Data were analyzed using descriptive statistics, correlation, and multiple regression with Baron and Kenny steps for mediation. Results: After investigating the mediating effect of a sense of job oppression in the relationship between emotional labor and work satisfaction, it was confirmed that the effect was partially meaningful. It was also determined that the greater the intensity of their emotional labor was, the lower was their satisfaction with their working life. Additionally, the workers felt that the greater their sense of job oppression, the lower was their sense of satisfaction with work. Conclusions: In order to increase work satisfaction, it is required for guidelines for reducing job oppression and the intensity of emotional labor to be proposed or established.

• 한국분말재료학회지
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• 제24권3호
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• pp.202-209
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• 2017

A cold-work tool steel powder is used to fabricate 3-dimensional objects by selective laser melting using a high-pressure gas atomization process. The spherical powder particles form continuous carbide networks among the austenite matrix and its decomposition products. The carbides comprise Nb-rich MC and Mo-rich $M_2C$. In the SLM process, the process parameters such as the laser power (90 W), layer thickness ($25{\mu}m$), and hatch spacing ($80{\mu}m$) are kept fixed, while the scan speed is changed from 50 mm/s to 4000 mm/s. At a low scan speed of 50 mm/s, spherical cavities develop due to over melting, while they are substantially reduced on increasing the speed to 2000 mm/s. The carbide network spacing decreases with increasing speed. At an excessively high speed of 4000 mm/s, long and irregularly shaped cavities are developed due to incomplete melting. The influence of the scan pattern is examined, for which $1{\times}1 mm^2$ blocks constituting a processing layer are irradiated in a random sequence. This island-type pattern exhibits the same effect as that of a low scan speed. Post processing of an object using hot isostatic pressing leads to a great reduction in the porosity but causes coarsening of the microstructure.

• 한국항해항만학회지
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• 제34권4호
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• pp.265-270
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• 2010

The national VTS was launched in 1993, and has adopted a harbour-oriented control method which is unable to consider enough characteristics of its work. However, for the past 17 years, the characteristics has changed due to increased amount of vessels. Up to now the domestic Vessel Traffic Service has adopted harbour-oriented control method which is unable to consider enough characteristics of its work. However, developed countries have carried out waters-oriented control method, according to the using areas of ships, to be well considered the characteristics of control for increasing efficiency of it. Especially, VTS of Daesan, Pyeongtaek and Inchon harbour can have confusions of control because of overlapped service areas of it. Therefore, in this paper suggested a new Sector Division that the relevants waters is divided into 3 operational Regions and these are divided into nine sectors again, for the purpose of improving the efficiency and the concentration of VTS.

• 대한교통학회지
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• 제30권4호
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• pp.61-70
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• 2012

본 연구에서는 2006년 수도권 가구통행실태조사 자료를 활용하여 비업무통행빈도에 대한 고령자의 통행특성을 분석하였다. 분석결과 비업무통행빈도에 대한 고령자의 통행특성은 타 연령층과 상이한 것으로 나타났으며, 분석모형은 특정 변수에 이분산성을 가정한 이분산 서열로짓모형의 설명력이 우수한 것으로 나타났다. 모형추정 결과 고령자는 연령층이 낮을수록, 여성일수록, 운전면허를 가지고 있을수록, 직업 및 가구내 미취학 아동이 없을수록, 그리고 가구내 특정수준 이상의 월평균소득이 있을 경우 비업무통행빈도가 증가하는 것으로 나타났다. 본 연구의 분석결과에 대한 정책적 시사점으로 모든 고령자에 대하여 획일적인 교통정책을 수립하는 것 보다 고령자의 개인적 특성차이(연령대별 건강상태 등)를 고려한 교통정책이 수립되어야 할 것으로 판단된다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 Proceedings of the 4th Korea-China Joint Workshop on Nuclear Waste Management
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• pp.114-129
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• 2004

The 3D simulations for the Rotary Specimen Rack (RSR), the shielding concret, and the reactor core dismantling processes in the Korea Research Reactor-1&2(KRR-1&2) were carried out in the present work. The four main dismantling items, which are the RSR, reactor core, beam tube, and the thermal column and the shield concrete, were selected among the many components in the KRR-2 by consideration of the activation, worker training, difficulty of the work and so on. On the basis of these, we built 3D CAD models, selected the proper dismantling technologies, and reviewed their dismantling processes. In this study, the 3D simulation results of the shielding concrete, and the reactor core dismantling processes are also presented and discussed.

• Asian-Australasian Journal of Animal Sciences
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• 제18권2호
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• pp.255-258
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• 2005

Several commercial yogurt starter cultures (L. acidophilus LA5, L. casei 01, L. acidophilus LA100, L. bulgaricus LB207 and L. rhamnosus GG744) were investigated for antioxidant activity by using in vitro assays. From the results of the present work, all strains tested showed varying degrees of antioxidant activity. L. bulgaricus LB207 showed the highest antioxidant activity, with a linoleic acid peroxidation inhibition of 81.3%. Hydroxy radical scavenging activity, ferrous iron chelating activity, reducing power and superoxide dismutase (SOD) activity were also studied. L. bulgaricus LB207 showed the highest hydroxy radical scavenging activity and L. casei 01 showed the highest chelating activity. L. bulgaricus LB207 and L. acidophilus LA100 showed good reducing power. All the strains in this study showed low SOD activity. The results of the present work suggest that antioxidant activity of L. bulgaricus LB207 due to its strong hydroxy radical scavenging activity and reducing power.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권4호
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• pp.221-228
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• 2005

In this work, our goal is to develop a fast and accurate power model of the ARM926EJ-S processor in the industrial design environment. Compared with existing work on processor power modeling which focuses on the power states of processor core, our model mostly focuses on the cache power model. It gives more than 93% accuracy and 1600 times speedup compared with post-layout gate-level power estimation. We also address two practical issues in applying the processor power model to the real design environment. One is to incorporate the power model into an existing commercial instruction set simulator. The other is the re-characterization of power model parameters to cope with different gate-level netlists of the processor obtained from different design teams and different fabrication technology.

• 한국산학기술학회논문지
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• 제21권11호
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• pp.326-333
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• 2020

본 연구는 맞벌이 부부의 결혼만족에 대한 이해를 위해 부부 각각의 성역할 태도, 다중역할 수행에서의 갈등과 향상의 경험이 자신과 배우자에게 미치는 상호영향을 살펴보았다. 이를 위해 맞벌이 부부 95쌍, 총 190명을 대상으로 하여 대응표본 t검증과 중다회귀분석을 실시하였다. 먼저 맞벌이 부부의 성역할태도, 다중역할 경험 및 결혼만족도에 있어 부부 간 차이를 살펴본 결과, 성역할태도 및 다중역할 경험에 있어 부부 간의 유의한 차이는 없었으며, 결혼만족도에 있어 남편이 아내보다 유의하게 만족하는 것으로 나타났다. 둘째, 맞벌이 부부의 결혼만족도에 영향을 미치는 요인에 대한 상호영향을 살펴본 결과, 부부 간의 결혼만족도에 영향을 주는 변인에서 유의한 차이가 발견되었다. 남편의 경우 자신의 성역할태도, 자신의 다중역할 향상이 결혼생활의 만족도에 정적으로 유의한 영향을 주는 반면, 아내의 경우는 남편의 성역할태도가 결혼생활 만족에 있어 정적으로 영향을 미치며 아내 자신의 다중역할 갈등이 결혼생활의 만족도에 부적인 영향을 미치는 것으로 나타났다. 이는 맞벌이 부부의 결혼만족에 관한 교육 및 프로그램에 있어 남편과 아내 각각의 영향과 상호간의 영향에 대한 고려가 필요함을 시사한다.

• 대한인간공학회지
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• 제34권4호
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• pp.293-302
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• 2015

Objective: This study was performed to investigate the prevalence of musculoskeletal disorders in auto workers of a mission assembly plants. Background: Most studies of musculoskeletal disorders have used car assembly line workers as their participants. However, little research has been done on musculoskeletal disorders afflictions of mission assembly line workers. Method: Through a focus group interview with an ergonomist and a manager at a mission assembly plant site, a questionnaire was developed for musculoskeletal disorders. The questionnaire consisted of five parts, demographic factors, musculoskeletal disorder symptoms, and musculoskeletal disorder experiences; 137 workers participated in this survey. The surveys were analyzed by correlation and Chi-squared analysis. Results: Musculoskeletal disorder symptoms and serious pain were reported in the neck, shoulder, back, and fingers. These problems were statistically related to various demographic factors, such as age, stature, stretching, and work satisfaction. Conclusion: Treatment of musculoskeletal disorders should consider the workers' traits. If there is no specific cause of the pain, developing stretches and exercises before and after work should be applied to prevent musculoskeletal disorders. Application: The results of this study can be used to develop guidelines to prevent injury in auto workers at mission assembly plants.