• Journal of the Korean Home Economics Association
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• v.48 no.5
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• pp.73-85
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• 2010

The purpose of this qualitative research is to explore the intergenerational ambivalence of mothers with preschoolers. Twenty full-time mothers and 19 working mothers were interviewed in depth. Most of the participants who received instrumental support from their mothers showed ambivalence, and especially the working mothers were more likely to feel ambivalence than the full-time mothers. However, participants who received little or no support from their mothers did not report any ambivalent feelings. Their ambivalent feelings came from both their social structure and intrapersonal contradictions. In order to avoid ambivalent feelings, some participants redefined receiving support from their mothers as a positive thing. Meanwhile, the participants who received active support tried to divert their ambivalence by providing child care support for their children, and they showed a 'repayment provision' tendency. Some working mothers and most of the full-time mothers said they would allot 'limited provision' by excluding child care support for their children. Those who were aware of this ambivalence issue sought 'reasonable provision' for their children. Depending on these results, several suggestions are presented to solve the ambivalence.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.28-34
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• 2016

When a electric power cable is installed in the air for newly or exchanged working, it is necessary at all time to hold a constant tension for an overhead power cable. And also a pendanted power cable is an extreme job to have work in a high sky. For this reason, the objective of this paper developments working robot for preventing disaster that tension of cable installed automatically power cable to hold a constant. So the working robot works at all the time two tasks for mobil and tension it come into a inference between two tasks, control is difficult. Control methode needs to suppress inference of two tasks. In this paper, for installation of overhead power cable, the scheme and control methode of working robot is presented. the robot work at a same time tow tasks that have hold a constant tension of the power cable and move a constant place while unfasten a winding cable at a drum on a chassis. Working robot consist of three parts with mobile system, tension system and control part. As it is applied the feedback/feedforward control, methode of hybrid control is established to suppress that interference come into between two tasks. The simulation programs is made out using models of mobil and tension system, and a proposed controllers. In accordance with simulation, the model of each systems is discussed to make out proper. And also parameters of controllers is selected a suitable value and the driving performance of robot is evaluated.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.4
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• pp.3956-3961
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• 1975

In order primarily to establish the working stages in the reclamation works and to- analyze the working characteristics of man-power, the investigations for construction_ works were conducted on Echeon Largescale Reclamation Project Area. The results are summarized as follows; 1. The working chart on reclamation by man-power is Fig.IV-1. 2. The. ratio of actual working time to total varied with the total times, being 1.0 for less than 4 hours but about 0.9-0.83 for more than 5 hours. 3. Felling operations can be classified into three stages as truck-cutting, branch- cutting, and binding-up, of which results are in Table IV-2. The larger the diameter of stands, the more times for both the cutting operations are, but the moving time is constant to be about 15 sec. 4. Stumping and clearing works have the results prepared in Table IV-3. Between the stumping time and the diameter of stands d, there show highly significant positive correlations, expressed as t=2.212d -4.792. The more the ratio of small diameters to total, the more hastily the total hourly working results of each person are increased. 5. Working results for constructing drainage facilities and ridges are in Table IV-5. The labours for placing patches of grass are required more than twice or three times as much as those are showed in the established standards, and such the different results imply more investigation to be necessary. 6. Table IV-6 sholvs the results for plowing andh arrowing, that are less amount thant the standards. Therefore, more inverestigation should be prepared.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1123-1134
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• 2020

The goal of this study was to develop an accelerated life test for an implement working pump for an agricultural tractor. The field experiments were conducted to measure the load of an implement working pump during major agricultural operations such as plow tillage, rotary tillage, baler operations, and wrapping operations. The measurement system for an implement working pump load was constructed using a pressure sensor, the engine rotational speed, and the hitch pump displacement. The measured implement working pump load was calculated as an equivalent load for each agricultural operation using the Palmgren-Miner rule, which is a cumulative damage method. The equivalent load was calculated using the total load data and peak load data when the total data included the operation of an implement working. The annual usage time of the agricultural tractor was applied to develop two integrated equivalent loads. The acceleration factor was calculated to develop an accelerated life test and was calculated from the two integrated equivalent loads, the maximum pressure, and the flow rate conditions of the hitch pump. In Korea, the warranty life of a tractor is 2,736 hours, and the time required for the test to guarantee the operational life of tractors was calculated as 7,561 hours. The acceleration factors were calculated as 453.6 and 38.3, respectively, from the total load data and peak load data. The fatigue test time can be shortened by 16.7 and 197.4 hours according to the result of the acceleration factors.

• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.18.1-18.7
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• 2023

South Korea has the highest policy priority for working hour regulations because it has longer annual working hours than other Organization for Economic Development Co-operation and Development countries and has fewer holidays. According to the results of the Working Conditions Surveys between 2006 and 2020, in 2020, 6% of wage earners worked for > 52 hours weekly. The percentage of workers exceeding 52 hours weekly has decreased over time; however, disparities exist based on age, industry, occupation, company type, and company size, particularly in service-, arts-, and culture-related occupations and workplaces with fewer than 5 employees. South Korea's working hours system is greatly influenced by the 52-hour weekly maximum; sometimes, a maximum of 64-69 hours, including overtime, is theoretically possible. To ensure healthy working hours, it is important to actively protect workers who fall through the cracks, such as those in businesses with fewer than 5 employees.

• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.28.1-28.12
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• 2023

Background: Owing to the coronavirus disease 2019 pandemic, being exposed to work from home and work during nonwork time simultaneously can lead to sleep disturbance; however, their combined effect is unclear. We aimed to investigate the combined effect of work from home and work during nonwork time on sleep disturbance. Methods: This study used data from the Sixth Korean Working Condition Survey and included 27,473 paid workers. Logistic regression analysis was conducted to investigate the relationship between work from home, work during nonwork time, and sleep disturbance according to sex. We re-classified participants into 4 groups based on their working from home (No/Yes) and working during nonwork time (No/Yes). The relative excess risk due to interaction was calculated to examine the effect of exposure to both telecommuting and non-regular work hours on sleep disturbance. Results: Workers exposed to work from home and work during nonwork time had significantly higher risks of sleep disturbance for all, men, and women workers (OR [95% CI]: 1.71 [1.46-2.02], 1.79 [1.43-2.23], and 1.64 [1.29-2.08] for work from home and 3.04 [2.70-3.42], 3.61 [3.09-4.22], and 2.41 [2.01-2.90] for work during nonwork time, respectively). Compared to those who were not exposed to both factors, when workers had both job factors, the ORs (95% CI) of sleep disturbance for all, men, and women were 3.93 (2.80-5.53), 5.08 (3.21-8.03), and 2.91 (1.74-4.87), respectively. The relative excess risk due to interaction of work from home and work during nonwork time was not significant for sleep disturbance. Conclusions: Work from home and work during nonwork time were each associated with sleep disturbance, but the interaction between the two factors on sleep disturbance was not observed in both men and women.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.3
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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.

• Human Ecology Research
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• v.56 no.4
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• pp.361-375
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• 2018

This study recognizes the changes of the father's role and the importance of family mealtimes as well as examines the individual, family and social contexts surrounding the father's family mealtime. This study analyzed the trend of the father's family mealtime frequency and factors affecting them in order to explore the current conditions of their father's work and family balance through family mealtimes. Data from 492 fathers who have school aged children were collected through an online survey. The overall trend of the frequency of father's family meals showed an average of 2.4 breakfasts and an average of 3.2 dinners per week. The frequency of the father's family meals showed statistically significant differences according to the father's age, children's school age, dual income, weekly working hours, working flexibility, leaving on-time and the priority of work and family. The analysis of hierarchical linear regressions was conducted to determine factors affecting the frequency of father's family mealtime to show that the frequency of father's family mealtime was best explained by father's working conditions and perception variables. Working conditions such as working hours, leaving work on time, working flexibility were significant variables in regards to the father's family mealtime frequency. The father's perception towards parental efficacy, wife's support, and work-family priority were significant factors in regards to the father's family mealtime frequency. This study is meaningful in that it provides basic data on policy making for the compatibility of the father's work and family.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.3
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• pp.20-25
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• 2003

The End-milling has been widely used in the industrial world because it is effective to cutting working with various shape. Recently the end-milling is demanded the high-precise technique with good surface roughness and rapid manufacturing time for precision machine and electronic elements. The cutting working of end-milling such as, cutting direction, revolution of spindle, feed rate and depth of cut have an effect on optimum surface roughness. This study was carried out to decide the working condition for optimum surface roughness and rapid manufacturing time by design of experiment and ANOVA. From the results of this study, the optimum working condition for end milling is upward cutting in cutting direction, 600rpm in revolution of spindle, 240mm/mm in feed rate, 2mm in axial depth of cut and 0 25mm in radial depth of cut. The design of experiment has become an useful method to select optimum working condition mend-milling.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.503-509
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• 2021

Objectives: The utility of the system was analyzed by applying the smart safety technology system to the aging pipe rehabilitation facility construction classified as a confined space. Methods: Smart safety management system was applied to a site where the aging pipe rehabilitation work was in progress. The working environment was measured for 25 days, and the toxic gas saturation was analyzed according to the working time and working place. Results: Based on the measured results, two characteristic environmental changes in the confined space were confirmed. First, when working inside an aging pipe, the tendency of carbon dioxide saturation increases with working time and the number of workers. Second, oxygen decreases when working in a space away from the entrance. Conclusions: Various applications of smart safety technology have been confirmed based on the measured data, and this is expected to be useful for environmental characteristic analysis and safety management when applied to a confined space composed with various conditions in the future.