• Tribology and Lubricants
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• 제37권3호
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• pp.112-116
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• 2021

Appropriate friction model usage is important for impact analysis because the relative motions between parts that are in contact for very short durations can vary greatly depending on the friction model. Vehicle seat components that have significant effects on impact analysis are also considered. This paper presents an experimental investigation of various material contact pairs to obtain the friction parameters of the Benson exponential friction model for impact simulation. The Coulomb friction model has limitations for impact analysis because of singularity at zero velocity. Metal/nonmetal materials are prepared, and friction tests are conducted for various sliding speeds, loads, and lubrication conditions. The obtained data are used in the friction model to implement finite element analysis. The parameters of the friction model are obtained by the curve-fitting method. The experimental results show that the friction coefficient with metal/nonmetal contact pairs is stable regardless of the working conditions. The friction model used in this study can also be applied for finite element analysis of the crash conditions, where the friction changes abruptly at the contact interface; the obtained friction parameters are also expected to be more accurate with more precise tests under different working conditions. These results can help improve the accuracy of the finite element analysis.

• 복식
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• 제63권8호
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• pp.27-42
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• 2013

The study was aimed to develop men's working pants patterns through the computerized 3-D virtual clothing simulation system and to verify the effects of the 3-D simulated outfit by comparing it to the images of the actual outfits. The average body measurements of South Korean men aged between 30 and 39 used for the simulation in order to generate a 3-D virtual model and to realize outfits of men's working pants for the workers in the heavy industry in South Korea. And also the preliminary questionnaire survey results on certain aspects of the working pants such as type, detailed design preference and discomforting parts were taken into consideration. Both the simulated and real images of the developed working pants were compared in terms of the ease amount according to parts of the working pants, the position of seam lines, the appearance of darts and pleats, and the effects of the fabric surface according to expertise panels' subjective 5-point scale evaluation. The results throughout the study were (1) the basic working pants item worn by subject workers were the straight one pleated pants. The most discomforting parts of the working pants were in the order of body rise, thigh, hip, waist, pants hems and knee girth. (2) the drafting factors of pants patterns differed by the men's body features, which was related to the allocation of suppression amounts between waist and hip girths into darts and hip curve amounts on the waist line level of the pants. (3) the similarity of the virtually simulated and real images of men's working pants resulted in an average of 4.5 to the ease of appearance, 4.6 to the seam lines, 4.1 to the fabric surface effects in a 5-point scale, which means that the two were highly alike.

• 생물정신의학
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• 제16권4호
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• pp.238-245
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• 2009

Objectives : Mild Alzheimer's disease(AD) is uncertain to be related to visuospatial working memory subsystem dysfunction. We used the self ordered pointing test(SOPT) to find the characteristics of visuospatial working memory in mild AD. Methods : We compared the visuospatial working memory abilities of 20 patients with mild AD and 20 normal elderly controls(NC) using SOPT, of which stimuli consisted of two stimuli types(A : abstract, C : concrete) and two stimuli numbers(8 and 12). Therefore, working memory was tested using C8, C12, A8, and A12 stimuli conditions in SOPT. Mixed-model ANOVA was conducted with the AD and NC groups as between-subjects factor, with stimuli types and stimuli numbers as the within-subjects factors and with SOPT error rates as the dependent variable. Results : The AD group showed higher error rates in SOPT than the NC group. The NC group showed low error rates in concrete stimuli than in abstract stimuli and in small stimuli numbers than in large stimuli numbers. And the AD group showed no differences between stimuli types or stimuli numbers. Conclusion : AD patients showed a poor performance in visuospatial working memory using concrete stimuli. The result suggests that there is a non-transformation from visual input to phonological working memory in AD. Patients with AD showed a poor performance although in small stimuli number condition of SOPT. It suggests that in AD, visuospatial working memory is not working well although in low central executive loads.

• 사회복지연구
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• 제40권1호
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• pp.323-351
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• 2009

본 연구는 '자녀가 있는 취업여성의 후속자녀 출산의도'가 어떠한 요인의 영향을 받으며, 어떠한 경로로 결정되는지를 규명하기 위한 연구이다. 본 연구는 특히 '가치관적 요인'의 영향력에 주목하여 '자녀가치관'을 특성에 따라 '개인주의적 자녀가치관'과 '집단주의적 자녀가치관'으로 구분하고 이외 주요 변수들과의 관계를 살펴볼 수 있는 연구 모형을 설정하였다. 본 연구를 통해 다음과 같은 결과를 얻을 수 있었다. 첫째, 본 연구에서 제안한 모형은 측정모형분석과 구조모형 분석을 통해 유자녀 취업여성의 후속출산의도를 설명하기에 적합한 모형인 것으로 확인되었다. 둘째, 우리나라에서 자녀가 하나 있는 취업여성의 후속자녀를 출산하고자 하는 의도는 여성의 '자녀가치관'에 의해 직접적으로 가장 강하게 예측될 수 있었다. 셋째, 경제적 자원과 공·사적 서비스 자원은 다른 요인을 매개하여 간접적으로 개인의 출산의도에 영향을 미치는 요인인 것으로 나타났다. 넷째, 경제적 자원은 공·사적 서비스 자원 경험 수준에 영향을 미치고 있었다. 다섯째, 개인주의적 자녀가치관과 집단주의적 자녀가치관은 일-가정의 양립과 관련된 여성의 환경 조건에 의해 영향을 받아 형성·변화될 수 있는 요인인 것으로 나타났다. 이러한 결과를 근거로 본 연구에서는 취업여성의 출산율 고양을 위해서는 이들의 일-가정 양립을 둘러싼 환경 조건의 변화를 통해 긍정적 자녀가치관을 형성하는 것이 중요함을 제안하였다.

• 한국생활과학회지
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• 제22권5호
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• pp.419-431
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• 2013

This study examined the childcare use pattern of the working mothers with preschool children and the factors affecting their use of multiple childcare. The 7th wave data of "Korea Welfare Panel Study" were analyzed for this study. The working mothers with preschool children were selected from the data set and a total of 292 working mothers were included in the analysis. More than 70% of the working mothers were using only one kind of childcare, mostly childcare center and kindergarten and 22.5% of the mothers were using more than two of childcare arrangements. Child factors, maternal factors, household factors, and economic factors were included in the hierarchical logistic regression model in the presented order to predict the use of multiple childcare. The results showed that the child's age and maternal education were positively related to the use of multiple childcare, while whether both parents live with the child, number of children within household, and the poverty status were negatively related to the use of it. Based on these results, we can confer that the main motive for multiple childcare use is to provide various experiences for their children.

• The Journal of Asian Finance, Economics and Business
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• 제7권3호
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• pp.115-125
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• 2020

This paper investigates the impact of working capital management on the firm's profitability. The research sample includes 119 non-financial listed companies on Vietnam stock market over a period of 9 years from 2010 to 2018. Two statistical approaches include Ordinary least squares (OLS) and fixed effects model (FEM) are employed to address econometric issues and to improve the accuracy of the regression coefficients. The empirical results show the negative and significant impacts of the working capital management, which measured by cash conversion cycle (CCC) and three components of the CCC including accounts receivable turnover in days (ARD), inventory turnover in days (INVD), and accounts payable turnover in days (APD) on the firm's profitability measured by return on assets (ROA) and Tobin's Q. It implies that firms can increase profitability by keeping the optimization of the working capital management measured by the CCC, which includes shortening the time to collect money from clients, accelerating inventory flow and hold the low payment time to creditors. Besides, the profitability of firms was impacted by the sale growth rate, firm size, leverage, and age. Therefore, this paper provides a new insight to managers on how to improve the firm's profitability with working capital management.

• 대한안전경영과학회지
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• 제16권3호
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• pp.257-266
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• 2014

This study was planned to investigate the effect of the exposure to hazard factors on work environment satisfaction. Existing researches about job satisfaction have focused on the general working conditions, such as working hours, wage, human relationship, job task and so on. Korean Working Conditions Survey was used for this study because that relevant questions were included. The effect of the exposure to hazard factors on work environment satisfaction may be produced by hierarchical regression analysis because of comparison with existing model for work environment satisfaction. The exposure to hazards factors were statistically significant effect on work environment satisfaction after adjusting other confounding variables, such as gender, age, educational level, job security, work hour, work load, work autonomy, social support, etc. This study has some limitation because that KWCS was cross sectional survey. Some researches about the causal effect and its mechanism may be suggested as future study.

• 동력기계공학회지
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• 제20권2호
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• pp.79-84
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• 2016

The thermodynamic performance of ocean thermal energy conversion with 1 kg/s geothermal water flow rate as a heat source was evaluated to obtain the basic data for the optimal design of cycle with respect to the classification of the working fluid. The basic thermodynamic model for cycle is rankine cycle and the geothermal water and deep seawater were adapted for the heat source of evaporator and condenser, respectively. R245fa, R134a are better to use as a working fluid than others in view of the use of geothermal water. It is important to select the proper working fluid to operate the ocean thermal energy conversion. So, this paper can be used as the basic data for the design of ocean thermal energy conversion with geothermal water and deep seawater.

• 대한안전경영과학회지
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• 제10권1호
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• pp.75-82
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• 2008

National technical qualification does not recognised degree of working-career in labor market and an industrial field situation. National qualification is supply to nurture expert manpower and accomplish of self-development and a duty accomplishment ability improvement at a side of personal. So, This study is purposed to find that a method for recognition of working-career on the national technical qualification system According to, this study is designed to questionnaire with BSC(Balaced ScoreCard), SEM(Structure Equation Model) with the delphi method, and is analysed using the AMOS 7.0 program package. Finally, This study is suggested growing to qualification standard for an examination a degree of master craftsman only under the change of national qualification systematization as a standard to operation and control.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2008년도 추계학술대회
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• pp.275-285
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• 2008

National technical qualification does not recognised degree of working-career in labor market and an industrial field situation. National qualification is supply to nurture expert manpower and accomplish of self-development and a duty accomplishment ability improvement at a side of personal. So, This study is purposed to find that a method for recognition of working-career on the national technical qualification system. According to, this study is designed to questionnaire with BSC(Balaced ScoreCard), SEM(Structure Equation Model) with the delphi method, and is analysed using the AMOS 7.0 program package. Finally, This study is suggested growing to qualification standard for an examination a degree of master craftsman only under the change of national qualification systematization as a standard to operation and control.