• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.108-113
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• 2006

The Work-Related Musculoskeletal Disorders(WMSDs) have been an rising issue since the 1970s. So many manufacturing companies have been tried to improve the work environments for the control and the prevention of the WMSDs. Specific risk factors associated with WMSDs include repetitive motion, heavy lifting, forceful exertion, contact stress, vibration, awkward posture and rapid hand and wrist movement. But recently it has reported that besides working conditions, job stress is the important hazard causes which lead to WMSDs. This study investigates the relation between WMSDs and Job stress from 1426 workers in Heavy Industry. Job stress was evaluated by Karasek's model. Job stress was associated with job satisfaction. Job demand was associated with the WMSDs, but job control was not associated with the WMSDs. The results can be used to design the management program for the WMSDs and the job stress.

• Journal of the Korea Safety Management & Science
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• v.5 no.3
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• pp.99-106
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• 2003

This study concerns with an ergonomic approach for improving the workplace of an air-conditioner factory. If work tasks and equipments do not include ergonomic principles in their design, workers may have exposure to undue physical stress, strain, and overexertion, including awkward postures, forceful exertions, repetitive motion, and heavy lifting. The purpose of this study is to improve the safety, comfort, and efficiency of the workplace. Adapting tasks, work stations, tools, and equipments to fit the worker can help reduce physical stress on a worker's body and enhance the effectiveness and efficiency of workplace.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.202-203
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• 2022

In this study, focusing on work types of lifting modules and modules assembly in modular construction sites, unit works were defined according to the construction process of each work type, and safety management elements, safety management activities, and key check point were proposed. The results of this study may have somewhat overlapping contents in the construction procedure in order to derive specific safety management activities and check point for each unit work. Therefore, there is a limit to use the results in an actual modular construction site. In future research, we plan to improve this part and derive a checklist that considers field usability.

• Journal of the Ergonomics Society of Korea
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• v.27 no.4
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• pp.27-35
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• 2008

Recently, many studies have reported the fact that an excessively accumulated psychological and physical burden induced from physical labor conducted routinely in home and industry can be one of main reasons of musculoskeletal disorders in the working population. This fact makes increase interests in studies to reduce a risk of musculoskeletal disorders through grafting ergonomic considerations on working environment. However, there are currently limited methodologies in quantitative evaluations of new ergonomic suggestions to reduce a risk of musculoskeletal disorders. The current study is therefore performed to evaluate quantitatively effects of a design of washing machine as a new ergonomic suggestion onto prevention of musculoskeletal disorders, through application of a biomechanical evaluation methodology. For this, three-dimensional motion analysis by using musculoskeletal models with Rapid Entire Body Assessment (REBA), which has been generally used for a simple evaluation of a degree of harmfulness of the human body at specific working postures to be considered, was performed. The results of REBA did not give us enough information and their results were somewhat simple and inaccurate, but the results of the three-dimensional motion analysis give us enough information such as alteration of main muscle forces and joint moments required during washing work. All results showed that the main muscle strengths and joint moments were decreased effectively for reduction of a risk of musculoskeletal disorders during the washing work with newly designed washing machine evaluated in the current study, compared with those generated during the washing work with general washing machine. From these results, it can be concluded that a risk of the musculoskeletal disorders, which may be induced by a repetitive washing work, may be reduced through using the washing machine designed ergonomically and newly. Also, it is thought that if our ergonomic design can be applied for improvement of working environment in lifting and laying works conducted repeatedly for a treatment work of goods, which have a strong resemblance to the behaviors generated frequently during the washing work, a possibility of occurrence of the musculoskeletal disorders by the lifting and laying works may be reduced highly.

• Journal of Preventive Medicine and Public Health
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• v.35 no.3
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• pp.197-204
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• 2002

Objectives : To evaluate the association between working conditions and adverse pregnancy outcomes in Korea. Methods : We obtained data on health history, lifestyle, housework and Working conditions, such as shift work, hours standing, working time, job demand, lifting at work and at home, between August and September 2000, from self-reported questionnaires. A group of 344, occupationally active, pregnant women from 51 industries were studied. Of the women studied, 328 women were further interviewed by telephone between November 2000 and September 2001. Result : Compared with daytime work, shift work increased the risk for preform birth (an adjusted risk ratio of 2.74, 95% CI=1.02-2.62) and low birth weight (an adjusted risk ratio of 2.74,95% CI=1.02-2.02). A significantly increased risk was found for prolonged standing, with an adjusted risk ratio of preform births of 6.80 (95% CI=2.01-23.0). There were no significant differences in the incidence of spontaneous abortion between the occupational working conditions, with the enception of a previous history of spontaneous abortion. Conclusion : These findings suggest that maternal working conditions, such as shift work and prolonged standing, contribute significantly to preterm birth and low birth weight.

• Safety and Health at Work
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• v.14 no.3
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• pp.243-249
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• 2023

Background: Southeast Asia has many people who work in the agriculture sector. Not many stakeholders pay special attention to the health of farmers, even though they are exposed to various types of hazards. One of the most common health complaints among farmers is related to work-related musculoskeletal disorders (WMSDs). This study aims to assess the prevalence of WMSDs and factors associated with them among farmers in Southeast Asia. Methods: A literature search on PubMed, ScienceDirect, Scopus, and EBSCO was conducted. Articles were included if they studied ergonomic problems among farmers from 11 countries in the Southeast Asia region and were published during 2015-2022. The Critical Appraisal Skills Program was used to evaluate the quality of the articles. The search process and retrieval process reflected PRISMA's recommendation. Result: There were 14 studies found from 3 countries that had published articles in PubMed and ScienceDirect, including Thailand [8], Indonesia [4], and Malaysia [2]. The prevalence of WMSDs in Thailand, Indonesia, and Malaysia was 78,31%, 81,27%, and 88,39%, respectively. Common factors associated with WMSDs include age, sex, smoking habits, drinking alcohol habits, working period (years), type of work, awkward position, non-ergonomic equipment, repetitive movements, and lifting heavy loads. Conclusion: The prevalence of WMSDs among farmers in Southeast Asia is considerably high. Effective intervention is essential for reducing the prevalence and protecting workers' health and well-being.

• Korean Journal of Mathematics
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• v.27 no.3
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• pp.767-777
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• 2019

We present a new way of obtaining the complete factorization of $X^n-1$ for n = 15, 17, 19 over the 4-adic ring ${\mathcal{O}}_4[X]$ of integers and thus over the Galois rings $GR(2^e,2)$. As a result, we determine all cyclic codes of lengths 15, 17 and 19 over those rings. This extends our previous work on such cyclic codes of odd lengths less than 15.

• Land and Housing Review
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• v.10 no.3
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• pp.77-87
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• 2019

In Korea, the modular construction method was applied to the construction of facilities such as military barracks and school dormitories, beginning with the pilot project of Seoul New Elementary School in 2003. In 2017, public modular houses were supplied to Busan(Yongho-dong) and Seoul(Gayang-dong), and modular housing is expected to continue to be supplied in the future. However, there is no clear construction standard for the modular housing construction yet, and there are few cases where the infill modular system is applied. Therefore, this study established the work breakdown structure and proposed a standard process focusing on the infill modular system applied to the construction of Dujeong-dong modular house in Cheonan. Level 1 of the work breakdown structure by construction stage of Infill modular was defined as modular manufacturing, assembly, and finishing process. Level 2 was defined as preparation, modular production, modular infill, modular fixing, floor plastering, building finishing, and other site finishing. Level 3 is defined as 57 detailed unit work of infill modular construction. The standard process of infill modular is proposed for the assembly stage that is commonly applicable to infill modular housing construction. The results of this study can be used for the process plan, transportation plan, lifting plan of modular housing construction.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.453-463
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• 2017

Due to the increase in the size of buildings and scale, the importance of construction engineering that reflects the constructability from the design stage of the project is increasing. Especially, engineering efforts related to facilities, equipment and construction methods for temporary work at the design stage can significantly contribute to improvement of constructability and project performance. The purpose of this study is to derive construction engineering tasks on temporary work at the design phase of the high-rise building projects. 27 preliminary tasks were firstly investigated through literature review and experts' group interview, and the necessity and importance analysis of each tasks were then performed based on questionnaire survey. Most of the tasks related to plans on structural framework and lifting equipment were analyzed as relatively more important ones. Lastly, 21 engineering tasks, which are classified into 5 factors, were proposed through factor analysis. The factors were determined as 1) structural framework, measurement and circulation, 2) lifting equipment and pumping, 3) space zoning, 4) water supply, 5) temporary facility, electric power supply and lighting. The results of this study can be used as basic data for establishing efficient work process of construction engineering on temporary work at the design phase.

• Journal of the Ergonomics Society of Korea
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• v.21 no.2
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• pp.25-33
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• 2002

The purpose of study is to investigate the relationship between the trunk muscle fatigue and recovery time during repetitive extension by using a surface electromyogram(EMG). Ten healthy subjects particioated in a simulated lifting task with five levels of recovery time and three levels of sub-maximal contraction. EMG signals of the L1(Lumbar 1st Vertebrae) and L3(Lumbar 3rd Vertebrae) level of the erector spinae muscle were recorded. and analyzed in terms of MPF(mean power frequency) parameter to quantify the level of muscle fatigue. It was found that MPF significantly (p<0.05) decreased during repetitive extension task at 50% and 75% sub-maximal contractions. Then it took minutes for the trunk muscle to recover from fatigue during 50% sub-maximal contraction. and it took five minutes during 75% sub-maximal contraction. and it took five minutes during 75% sub-maximal contraction. The recovery time estimated by the maximum force needs to be re-evaluated for the trunk muscle to fully recover from fatigue. In conclusion. the work/rest cycle needs to be studied based upon the information of muscle fatigue in order to prevent workers from musculoskeletal injuries during repetitive lifting task.