• Animal cells and systems
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• v.14 no.1
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• pp.11-15
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• 2010

Long-term working memory (LTWM) is a subdivision concept of working memory and indicates the enhancement of performance in a working memory task. LTWM has been shown in humans who have been engaged in a specific task requiring working memory over a long time. However, there is very little understanding of the exact mechanism of LTWM because of limitations of experimental methods in human studies. We have modified the standard T-maze task, which is used to test working memory in mice, to demonstrate LTWM in an animal model. We observed an enhancement of performance by repeated experience with the same working memory load in mice, which can be regarded as an LTWM. This effect seems to depend on the condition wherein a delay was given. This task may be a good experimental protocol to assess LTWM in animal studies.

• Journal of Environmental Health Sciences
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• v.46 no.5
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• pp.539-547
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• 2020

Objectives: This study was performed to emphasize improvement of the perception of dental hygienists' environmental working conditions by analyzing various factors. Methods: Two hundred ninety-eight female dental hygienists working at 35 medical institutions in Daegu City and Gyeongsangbuk-do Province participated. A self-recording type survey was done in October 2016. Results: Factors influencing the perception of infection control was length of career. Dental hygienists with more experience have a higher level of perception. Factors influencing the perception of working posture was the number of patients per day and career level. Dental hygienists seeing 50 or fewer patients per day and senior staff showed higher levels of this perception. Factors influencing the perception of noise in the working area were length of career and lunchtime break. The perception level was high in the group with longer careers and dental hygienists who rest at lunch time. Factors influencing chemical exposure during work were the number of patients per day and the type of institute. Dental hygienists working in dental clinics or dealing with more patients had lower levels of perception. Conclusions: The sociodemographic and working characteristics of dental hygienists influence the perception of dental hygienists' environmental working conditions.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.6 no.2
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• pp.149-166
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• 2011

This study investigates how the job satisfaction of the recipients with working ability is transformed into employment under the recent trends. The objects of this research are 15-19 years old. I used the data of YP2007. This survey were analyzed F-test by using SPSS PC win 12.0. This result maintain the importance about the policy of the recipients with working ability : (1) its bridging gaps between theory and reality, (2) focus on the Job satisfaction of the recipients with working ability, (3) developing new recipients with working ability education program, (4) elaborating the study methods. In this paper I describe one line of research focused on the job satisfaction of the recipients with working ability in view of their professional life as it is currently developed and expressed. This study also requires further studies and this study will be supplemented.

• Journal of Korean society of Dental Hygiene
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• v.15 no.3
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• pp.539-546
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• 2015

Objectives: The purpose of the study is to investigate the impact of working environment on the subjective health symptoms in the dental hygienists. Methods: The subjects were 220 dental hygienists in Gwangju and Jeonnam. A self-reported questionnaire was completed from September 9 to 22, 2012. The questionnaire was adapted and modified from building symptom index of workers in large buildings by O. The questionnaire consisted of eight questions of the general characteristics of the subjects, 19 questions of working environment and job satisfaction, nine questions of working environment characteristics, and six questions of subjective health symptoms. The questionnaire was measured by Likert 4 scale. Cronbach's alpha in this study was 0.826. Except incomplete answers, 192 data were analyzed using SPSS 19.0 program including t-test, ANOVA, and multiple regression. Results: The health symptoms were statistically and significantly different in glasses wearer and contact lens wearer, working hour satisfaction, and indoor environment(p<0.05). The subjective health symptoms were statistically different from the salary satisfaction, human relations satisfaction, office air environment, indoor environmental awareness score(p<0.05). Conclusions: It is necessary to improve the pleasant indoor working environment by providing the efficient working environment for the health care providers.

• Geomechanics and Engineering
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• v.20 no.5
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• pp.447-459
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• 2020

Based on the literature statistical method, the paper publication status of the isolated working face and the distribution of the rockburst coal mine were obtained. The numerical simulation method is used to study the stress distribution law of working face under different mining range. In addition, based on the similar material simulation test, the overlying strata failure modes and the deformation characteristics of coal pillars during the mining process of the isolated working face with thick-hard key strata are analyzed. The research shows that, under the influence of the key strata, the overlying strata formation above the isolated working face is a long arm T-type spatial structure. With the mining of the isolated working face, a series of damages occur in the coal pillars, causing the key strata to break and inducing the rockburst occurs. Combined with the mechanism of rockburst induced by the dynamic and static combined load, the source of dynamic and static load on the isolated working face is analyzed, and the rockburst monitoring methods and the prevention and control measures are proposed. Through the above research, the occurrence probability of rockburst can be effectively reduced, which is of great significance for the safe mining of deep coal mines.

• The Journal of Korean Obstetrics and Gynecology
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• v.21 no.3
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• pp.231-244
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• 2008

Purpose: The purpose of this study is to analyze body composition, obesity according to working pattern of working women. The subjects were workers in the automobile manufacturing industry. Methods: The subjects consisted of 514 industrial women workers who had received Korean oriental medicine health examination and submitted questionires about working pattern, during 8 months from April 2005 to November 2005. The body composition was measured by X-scan(Jawon medical, Seoul, Korea). We analyzed the relationship between body composition analysis, obesity and shift pattern with $X^2-test$ using the SPSS Ver. 12.0 Results: Regarding the realationship between body composition and working pattern, shift worker group had a significantly higher level of body weight, ratio of body fat, visceral fat and abdominal fat than normal worker. Conclusion: From this study, we can know that shift work can influence on working women's body composition and obesity.

• Safety and Health at Work
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• v.2 no.4
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• pp.313-320
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• 2011

Objectives: To analyze the association between changes in perceived physical and psychosocial working conditions and change of sickness absence days in younger and older (< 50 and ${\geq}50$ years) food industry employees. Methods: This was a follow up study of 679 employees, who completed working conditions survey questionnaires in 2005 and 2009 and for whom the requisite sickness absence data were available for the years 2004 and 2008. Results: Sickness absence increased and working conditions improved during follow-up. However, the change of increased sickness absence days were associated with the change of increased poor working postures and the change of deteriorated team spirit and reactivity (especially among < 50 years). No other changes in working conditions were associated with the changes in sickness absence. Conclusion: Sickness absence is affected by many factors other than working conditions. Nevertheless, according to this study improving team spirit and reactivity and preventing poor working postures are important in decreasing sickness absence.

• Korean Journal of Occupational Health Nursing
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• v.23 no.4
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• pp.277-286
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• 2014

Purpose: In this study, I am going to figure out Korean workers' actual exposure to risk factors and percentage of the workers who complain of health problems by performing a comparative analysis of the characteristics of the workers and working conditions in Korea and EU. Methods: The data used in this study includes the $1^{st}$ working conditions survey conducted in 2006 in Korea, the $2^{nd}$ working conditions survey in 2010, the $4^{th}$ EU working conditions survey, and the $5^{th}$ EU working conditions survey. I have compared the changes to Korean working conditions and those to EU working conditions in the categories of demographic characteristics, quality of labor, exposure to risk factors, and health problems included in the data. Results: The analysis of the characteristics of the demographic characters of Korean workers shows that aged and female workers register increased labor force participation. The analysis of labor quality shows that Korea has a long working time but with a lower work intensity compared to the countries included in EU working conditions survey. As for risk factors, Korea registers a low level of exposure as compared to countries included in EU working conditions survey and characteristically shows a decreasing exposure to tobacco smoke. The survey shows sharply increasing complaints of muscle pain in the upper and lower limbs. Conclusion: In this study, I have identified vulnerable social groups by using quantified values in a comparison of the working conditions of Korea and those of EU.

• Safety and Health at Work
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• v.15 no.1
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• pp.73-79
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• 2024

Background: This study aimed to investigate the relationship between work-related communication devices use during work outside of regular working hours and depressive symptoms in wage workers. Methods: Data from 50,538 workers aged 15 years or older who had participated in the 6th Korean Working Condition Survey (KWCS) were used. The final sample was 32,994 wage workers. The questionnaire asked the respondents how often they used communication devices for work during work outside of regular working hours. Depressive symptoms were assessed using WHO-5 Well-Being Index. Multiple logistic regression analysis was used to analyze the association between work-related communication devices use during work outside of regular working hours and depressive symptoms. Results: The rate of depressive symptoms was highest among workers who did not use work-related communication devices during work outside of regular working hours. After adjusting for socio-demographic and work-related factors, the odds ratio of depressive symptoms among workers who used communication devices when working outside of regular working hours was 1.20 (95% CI: 1.09-1.32); the odds ratio of depressive symptoms in the group not using communication devices for free-time work was 1.66 (95% CI: 1.37-2.00), which was higher than that of the reference group, that is, workers who did not work outside of regular working hours, and was statistically significant. Conclusion: Regardless of whether work-related communication devices are used, working outside of regular working hours increases depressive symptoms. The use of work-related communication devices during work outside of regular working hours can reduce the rate of depressive symptoms.

• Annals of Occupational and Environmental Medicine
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• v.34
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• pp.2.1-2.14
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• 2022

Background: Because income and working hours are closely related, the health impact of working hours can vary according to economic status. This study aimed to investigate the relationship between working hours and the risk of poor self-rated health according to household income level. Methods: We used the data from the Korea National Health and Nutrition Examination Survey VI and VII. The information on working hours and self-rated health was obtained from the questionnaire. After stratifying by household income level, the risk of poor self-rated health for long working hour group (≥ 52 hours a week), compared to the 35-51 working hour group as a reference, were calculated using multiple logistic regression. Results: Long working hours increased the risk of poor self-rated health in the group with the highest income, but not in the group with the lowest income. On the other hand, the overall weighted prevalence of poor self-rated health was higher in the low-income group. Conclusions: The relationship between long working hours and the risk of poor self-rated health varied by household income level. This phenomenon, in which the health effects of long working hours appear to diminish in low-income households can be referred to as the 'poor worker's long working hours paradox'. Our findings suggest that the recent working hour restriction policy implemented by the Korean government should be promoted, together with a basic wage preservation to improve workers' general health and well-being.