• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.2
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• pp.229-238
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• 1997

A third-order simulation model of VM heat pumps has been developed. This model allows consideration of the major losses such as heat conduction losses through regenerators and displacers, pumping losses and wall-to-gas heat transfer losses in working volumes, in addition to the heat exchanger and regenerator losses. The working volume was divided into 12 control volumes and conservation equations of mass and energy were applied to each control volume. Pressure drop was considered in regenerators only. Thermodynamic behavior of working fluid in a VM heat pump was investigated and effects of major losses on the performance of a VM heat pump were shown.

• The Korean Journal of Applied Statistics
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• v.13 no.2
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• pp.321-328
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• 2000

Working day variations caused by trading days, holidays and leap year make it difficult to analyze monthly or quarterly economic time series. In this paper, we adjust working day variations from economic time series via RegARIMA model.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.4
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• pp.37-42
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• 2004

End-milling have been widely used in aircraft, automobile part and moulding industry. However, various working factors such as spindle speed, feed rate and depth of cut in end-milling have an effect on spindle vibration. There it is demanded the quantitative analysis of spindle vibration in order to get the optimum surface roughness. This study was carried out to analyze an influence of working factors on spindle vibration by design of Experiment. The results are shown that mathematical model of regression equation for an influence of working factors on vibration acceleration of spindle in end-milling by regression analysis is presented.

• Journal of the Korea Safety Management & Science
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• v.24 no.3
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• pp.39-46
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• 2022

This study has found the socio-economic factors that affect occupational accidents and measured the influence quantitatively. We built the panel data of 4 countries (Japan, Germany, the U.S., and the U.K.) and the analysis model counted on the fixed effect model to reflect the countries' differences. The fatal occupational injury rates in the analyzed countries had a statistically significant relationship with the level of per capita GDP, the proportion of the construction industry, the rate of male workers, annual average working hours, the rate of workers in manufacturing and construction industries, etc. The annual average working hours have a positive correlation with the fatal occupational injury rate. To reduce occupational accidents effectively, we should be monitoring and researching various factors that can affect the occurrence of occupational accidents such as worker characteristics, changing industrial structure, and changes in working hours.

• Korean Journal of Child Studies
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• v.27 no.1
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• pp.31-44
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• 2006

This study focused on the lives of working mothers in its examination of the meaning of an employer supported educare center. Ethnographic methods including participant observation, in-depth interview, and the analysis of documents were used for the case study at D educare center where management has been entrusted to K University. Results showed that employer supported educare center had significant meanings in the lives of working mothers. Meanings consisted of stories about relieving time conflicts, adapting themselves to life space, putting confidence in the educare center, and organizing community. Meanings gained from this study suggest that D educare center could be a model for employer supported educare centers focused on the lives of working mothers.

• Korean Journal of Cognitive Science
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• v.35 no.1
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• pp.1-21
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• 2024

This study investigates the characteristics of visual working memory (VWM) representations by examining two theoretical models: the integrated-object and the parallel-independent feature storage models. Experiment I involved a change detection task where participants memorized arrays of either orientation bars, colored squares, or both. In the one-feature condition, the memory array consisted of one feature (either orientations or colors), whereas the two-feature condition included both. We found no differences in change detection performance between the conditions, favoring the integrated object model over the parallel-independent feature storage model. Experiment II employed a recall task with memory arrays of isosceles triangles' orientations, colored squares, or both, and one-feature and two-feature conditions were compared for their recall performance. We found again no clear difference in recall accuracy between the conditions, but the results of analyses for memory precision and guessing responses indicated the weak object model over the strong object model. For ongoing debates surrounding VWM's representational characteristics, these findings highlight the dominance of the integrated object model over the parallel independent feature storage model.

• Research in Community and Public Health Nursing
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• v.29 no.1
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• pp.41-53
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• 2018

Purpose: This study was conducted to identify the factors affecting on unmet healthcare needs of married immigrant women, especially who are working in South Korea. Methods: It is designed as a cross-sectional descriptive study. We analyzed data from 8,142 working married immigrant women to the 'National Survey of Multicultural Families 2015.' Based on Andersen's health behavior model, logistic regression was conducted to determine the predictors of unmet healthcare need. Results: The prevalence of unmet healthcare needs among the subjects was 11.6%. In multivariate analysis, significant predictors of unmet needs included existence of preschooler, country of origin, period of residence in predisposing factors, monthly household income, helpful social relationship, social discrimination, Korean proficiency, working hour per week in enabling factors, and self-rated health, experience of grief or desperation in need factors. Conclusion: The association between labor-related factors and unmet healthcare needs of marriage immigrant women currently working was found from nationally representative sample. Support policies for immigrant women working more than legally defined hours and having preschooler should be supplemented to reduce unmet healthcare needs. In addition, eradicating discrimination in workplace, enlarging social relationship, and developing culturally competent nursing services tailored to health problems caused by labor are needed.

• Korean Journal of Childcare and Education
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• v.15 no.3
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• pp.21-38
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• 2019

Objective: The goal of this study was to investigate the effects of early childhood teachers' current working conditions such as welfare and wages, working hours, ECEC center's environmental characteristics, and parental involvement and community engagement on the professionalism of teachers. Method: A total of 988 respondents participated in the nationwide online survey. The data were analyzed by correlation analysis and structual equation modeling. Results: First, there were no statistically significant direct effects of ECEC teachers' working conditions on teacher professionalism. Second, there were significant direct effects of teacher efficacy and well-being on teacher professionalism. Third, there were significant indirect effects of teachers' working conditions on their professionalism, via efficacy and well-being, linking the impact of working conditions and the professionalism of teachers. Conclusion/Implication: The results of this structural model imply that policy input for teacher welfare, wage increases, and the enhancement of teachers' well-being and efficacy are valid and significant for the professional development of ECEC teachers. These results provide the data-driven evidence for the importance of welfare and socio-cognitive approaches for teachers.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.656-660
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• 2009

Various dynamic models of seated posture human body have been developed because the importance about the ride comfort assessment of vehicles is highly emphasized from day to day. The dynamic models of human body make possible the simulation of ride comfort assessment by applied to the vehicle dynamic model. Recently, the importance of ride comfort is also regarded to working vehicles such as excavators and the research of the ride comfort assessment for working vehicle is required. Only vertical vibration dominantly occurs on the seat of the private car driving with constant velocity. In contrast, vertical/fore-and-aft/pitch vibration seriously occurs on the seat of the working excavator. So, the dynamic models of seated human body applied to working vehicles should describe the dynamic characteristics for vertical/fore-and-aft/pitch direction. In this paper, the dynamic characteristics of seated human body are represented as apparent inertia matrix. The apparent inertia matrix is obtained by the vertical/fore-and-aft/pitch excitation of seated human body. 6 resonance frequencies are observed in apparent inertia matrix. This result can be applied to develop the dynamic model for seated posture human body.

• Journal of Labour Economics
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• v.35 no.3
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• pp.83-100
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• 2012

This paper estimates the impacts of introducing the 40 hour work week standard in South Korea on actual working hours, wages and employment. We exploit variation in timing of implementing the 40 hour work week standard across industries and establishment size and estimate the causal effects by a triple difference model. Our results show that the 40 hour work week standard decreased actual working hours by about 43 minutes while it increased hourly wage rate by 6.6%. The probability of new hires decreased by about 2.3% points.