• 충청수학회지
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• 제19권4호
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• pp.437-443
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• 2006

We study free actions of finite groups on the 3-dimensional nilmanifold for Type 1 and classify all such group actions, up to topological conjugacy. This work supplies missing one in [1, Theorem 3.11.].

• 한국재료학회:학술대회논문집
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• 한국재료학회 1992년도 추계학술발표강연 및 논문개요집
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• pp.1-1
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• 1992

Shape Memory Alloys have attracted the interest of a great number of researchers in the world, and Mexico is not the exception. Research in this field started ten years ago, and is actually an active line covering the classical Cu-based and Ti-Ni alloys, but also the new Fe-based alloys. Although more basic studies have been performed at the present time, interest for applied research and technological goals is increasing. In this work we present a series of studies carried on these Shape Memory Alloys by the groups in Mexico, and explain what the interest of our groups are in the next future in this are of the Materials Science. Interdisciplinary work has been necessary in the characterization of the different alloys, and multiple techniques have been used, like Mossbauer spectroscopy, thermoelectric power, electron microscopy, ultrasound techniques, neutron and x-ray diffraction, calorimetry, among others. Collaboration With other groups in Europe and in the United States have become highly useful and productive, and some examples of such activities are also reported.

• 한국과학교육학회지
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• 제17권1호
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• pp.103-113
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• 1997

The purpose of this study was to identify the preferable learning strategies in science learning and to find out the relationship between these strategies and scientific achievement of students in the secondary school. The learning strategies were tested with two categories, self-focused and work-focused learning. The four types of learning strategies in science learning were analyzed, and they were named to organization, monitoring, elaboration and memorization strategies, which were defined by GSSS test. In the self-focused learning, the organization and monitoring strategies were preferred to the elaboration and memorization strategies. Middle school students had a preference for memorization strategy (p=0.000), whereas high school students had a preference for monitoring strategy (p=0.015). In the case of organization strategy, female groups were preferable to male groups (p=0.027). In the second form of learning types, work-focused learning, the memorization strategy was the same preference as organization and monitoring strategies in the secondary school students, especially the male groups of high school students. The preference of elaboration strategy was relative lower compared with that of self-focused learning type. Middle school students had a preference for monitoring strategy (p=0.001), whereas high school students had a preference for elaboration strategy (p=0.001). The difference of each preference between male and female groups was not shown. From the analysis of correlation between learning strategy and scientific achievement, it showed that the monitoring strategy was commonly correlated with scientific achievement. In the self-focused learning, elaboration and organization strategies were correlated with scientific achievement in high school students (p<0.05). In the work-focused learning, memorization strategy was correlated with scientific achievement in middle school students, especially in male groups (p<0.05).

• 한국주거학회논문집
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• 제15권1호
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• pp.129-140
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• 2004

The purpose of this study was to identify the general characteristics of test subjects in association with three planned housing alternatives in different focus level of work opportunities, leisure activities and services. Subjects used in the study were people in their 50's who were surveyed in 2002. A total of 464 subjects were selected from 556 samples. Statistical significance was found between the preferred housing alternatives and the subjects' background including education level of the subjects and their spouses, monthly income, assets, subjective economic capabilities, and housing size. However, there was no statistically significant differences in recognition of housing problems for later life among groups. Groups selecting different planned housing alternatives showed statistically significant differences for some features of the senior housing. From these results, it is proposed that various designs based on the levels of work opportunities, leisure activities, and services for the senior housing should be provided to satisfy the demands.

• 대한안전경영과학회지
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• 제16권3호
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• pp.219-229
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• 2014

Employees used computer significantly(IT employee) is increased by technological development in workplace. This study tried to find the magnitude of IT employees and the profile of their working conditions and ill health experiences in South Korea. Korean Working Conditions Survey was used with descriptive and mean difference test in order to find the difference working conditions and ill health status among the groups classified by the degree of using computer during work. Some of working conditions was positively correlated with the density of computer use such as work autonomy, the exposure of repetitive movement of hand and arms. The pain of upper extreme was also more frequently found in the highest user group of computer than lower user groups. Based on the result of hierarchical regression analysis, the effect of computer using on the experience of work-related symptoms after controlling other factors was shown as U shape. This study as heuristic one suggest that some of depth analysis with hypothesis will be done to identify the causes and pathway of impact of computer use.

• The Journal of Korean Physical Therapy
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• 제3권1호
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• pp.123-149
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• 1991

This study has been attempted to be helpful for the back rehabilization of Korean workers by analyzing the general, occupational, social aspects of low back pain and to identify possible risk factors for back pain in White and Blue collar workers. The primary data were collected from 380 workers in Seoul city by means of a Questionnaire with random which was distributed from March 10 to 31, 1990. For the test of statistical significance, chi-square analysis was used to compare the back pain characteristics between above two groups. The results were as follows : 1. The incidence of low back pain in all walkers studied was $79.7\%$. The incidence of Blue collar with low back pain $(87.2\%)$ was higher than that of White collars $(75.0\%)$. 2. With regard to the relationship of back pain to the occupational characteristics, statistically significant differences were observed between workers with and without back pain concerning the job factors on work-time, job satisfaction, mental stress, chair fittness, work posture, work rotation, weight lifting, monotonous repetitive movements, vibration, and heavy noise (p<0.05). 3. With regard to the relationship of back pain to the social characteristics, there were no differences with respect to having car, personality types, drinking habits, and leisure-time activities. However, significant differences were showed between no pain and pain groups for the using bed, sleeping posture, traffic time amount, walking health state, smoking habits, and physical exercise (p<0.05). 4. The comparative analysis of back pain related to work factors showed highly significant differences with respect to mental stress, chair fittness, work posture, trunk rotation, weight lifting, monotonous repetitive work in White collar group (p<0.01) ; and job satisfaction, mental stress, trunk rotation, weight lifting, monotonus repetitive work, exposure to vibration and heavy noise in Blue collar group(p<0.01). 5. The comparative analysis of social factors in two groups showed differences with respect to the using bed, sleeping posture, walking amount, health state, physical exercise, smoking habits in White cellar group (p<0.05) ; and walking amount, traffic time amount, health state, smoking habits, physical exercise in Blue cellar group (p<0.05). 6. In regard to the general aspects of back pain between two groups, there were differences concerning etiolgy of back pain, counselling partners, treatment types, and sick-leaves(p<0.05), except pain duration, and awareness of back pain.

• 한국생활과학회지
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• 제16권1호
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• pp.137-143
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• 2007

The purpose of this study is to prove the work efficiency of PDS by measuring the work time on the process of pattern making of woman's tailored jacket. Also compared to the manual work time, PDS work efficiency is estimated according to experience difference. The YUKA CAD system was used. Through analysis of PDS Process, work time was measured by stop watch. Also the appearance of the 2 jackets was evaluated by a pool of evaluators consisted of graduate students and experienced professional modelist. The results were as follows: The work efficiency of PDS is higher than the work efficiency of manual work. There were significant differences of work time between work types in the expert and inexpert group. A study compared the work efficiency by PDS work type with those by manual work type according to experience difference and found that the work efficiency by PDS in the expert group was 25.3%, in the inexpert group was 35%. There were significant differences of work time between experience groups in PDS work, the work efficiency of expert group to inexpert group in the total pattern making time by PDS was 36.7%. There were no significant differences of appearance of tailored jacket between work types.

• 대한영양사협회학술지
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• 제20권4호
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• pp.296-305
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• 2014

This study evaluated the effects of sanitary education administered to elementary and middle school foodservice employees with work experience. The subjects of this study were 360 school foodservice employees in Gyeonggi-do during August, 2010. Sanitary education and awareness were assessed using three major dimensions: food sanitation (six items), personal hygiene (five items), and environmental sanitation (three items). Each dimension was categorized according to several items in the form of a self-evaluated Likert 5 point scale. The data were analyzed using SPSS WIN Version 12.0 package. The results showed that employees who worked for 5~10 years in the foodservice industry scored better in three dimensions before sanitary education compared to other groups. After sanitary education, all employees scored better in food sanitation than before, and employees who worked less than 5 years scored better at personal hygiene dimension than other groups. For environmental sanitation, employees who worked for 5~10 years scored better than other groups. Employees who worked for more than 10 years scored worse before and after sanitary education but scored highest for sanitary awareness. Employees between the ages of 31 and 40 showed significantly different scores before and after sanitary education.

• 가족자원경영과 정책
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• 제24권3호
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• pp.19-33
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• 2020

The purpose of this study was to investigate whether paid work time desynchronization affected housework time desynchronization. Time slot data from the Korean Time Use Survey data from 2014 was analyzed. This study included 1,475 married couples aged 20 to 59. They were dual-earner couples, heterosexual couples, and both partners worked during the day, either durong the week or on the weekend. The data was analyzed by the following four groups: weekday-husband, weekday-wife, and weekend-husband, weekend-wife. The results demonstrated that as the desynchronization of paid work increased, the desynchronization of time spent on housework in the weekday-husband and weekend-husband groups also increased. Second, the amount of leisure time did not affect the desynchronization of time spent on housework. Lastly, the amount of time that one person spent on housework increased the housework time desynchronization level. In addition, if the family had children who attended primary, middle, or high school-mothers in the weekday-wife group completed more housework. These results demonstrated that paid work time desynchronization might be a way to decrease the amount of time that dual-earner wives' spent housework.

• Safety and Health at Work
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• 제10권1호
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• pp.3-20
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• 2019

This review aimed to identify risk factors for occupational accidents and illnesses among young workers in the Nordic countries and to attain knowledge on specific vulnerable groups within the young working force that may need special attention. We conducted a systematic review from 1994 to 2014 using five online databases. Of the 12,528 retrieved articles, 54 met the review criteria and were quality assessed, in which data were extracted focusing on identifying occupational safety, health risk factors, and vulnerable groups among the young workers. The review shows that mechanical factors such as heavy lifting, psychosocial factors such as low control over work pace, and organizational factors such as safety climate are all associated with increased injury risk for young Nordic workers. Results show that exposures to chemical substances were associated with skin reactions, e.g., hand eczema. Heavy lifting and awkward postures were risk factors for low back pain, and high job demands were risk factors for mental health outcomes. The review identified young unskilled workers including school drop-out workers as particularly vulnerable groups when it comes to occupational accidents. In addition, apprentices and young skilled workers were found to be vulnerable to work-related illnesses. It is essential to avoid stereotyping young Nordic workers into one group using only age as a factor, as young workers are a heterogeneous group and their vulnerabilities to occupational safety and health risks are contextual. Politicians, researchers, and practitioners should account for this complexity in the education, training and organization of work, and workplace health and safety culture.