• Fashion & Textile Research Journal
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• v.19 no.4
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• pp.504-514
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• 2017

Discomfort as well as muscular pain and musculoskeletal diseases occur in cases of stressed posture due to prolonged pressure. Therefore, the American Academy of Orthopaedic Surgeons (AAOS) and Pediatric Orthopaedic Society of North America (POSNA) recommend that bags that weigh no more than 15 - 20% of the wearer's weight. However, despite the prolonged pressure from using baby carriers, there are no recommendations and limited studies on how to protect wearers. Therefore, this study investigates subjective fatigue according to the usage of waist support and hip seat. Based on this, muscle fatigue and secondary subjective fatigue according to three types of currently commercial baby carriers (X-type, H-type, and H-hip type) were measured. Subjective comfortability was evaluated on a 5 point Likert-scale and subjective fatigue was evaluated on Borg's CR-10 scale. Objective muscle fatigue was also compared by measuring and analyzing electromyogram (EMG). The results of primary subjective fatigue showed statistically significant changes in the shoulders, waist, calves, and soles of the feet according to the usage of hip seats and waist support. Electromyogram measurements also showed less muscle fatigue at the upper trapezius muscle and thoracic erector spine muscle for the H-hip seat baby carrier, which has both waist support and hip seat, compared to an X-type baby carrier, which has neither. However, results of subjective fatigue showed opposite results at the waist despite having same results at the shoulders and beneath the shoulders. This show discrepancies between objective muscle fatigue and subjective fatigue; therefore, that both aspects must be taken into consideration when developing ergonomic baby carriers.

• Journal of the Korea Society of Computer and Information
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• v.23 no.4
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• pp.121-129
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• 2018

The purpose of this study is to provide a basic data of clothing development which can improve the satisfaction of the body shape by examining the subjective evaluation and type characteristics of the old-old women themselves. Q methodology was used for the study of subjectivity. The types of the body shape of the old-old women were analyzed as five types: bent body with protruding abdomen, backward bent body with slender legs, inverted triangle, swollen cylinder, triangle. The bent body with protruding abdomen had a bent back and waist. They were recognized that the bust and shoulders were sagging and abdomen was protruding. The backward bent body with slender legs was the smallest of the five types with a BMI index and shoulders and bust were sagging. And knee and waist were bent and legs were thin. The inverted triangular shape showed the highest BMI index among the 5 types, indicating that it is obese. They thought that the upper body was developed and the lower body and legs were slender. The swollen cylinder shape was analyzed to be the smallest and the most fat body. The triangle shape had developed lower body and bent back and waist. It is considered that a design consideration is needed to cover the disadvantages of the body shape in consideration of not only wearing feeling but also aesthetic part when making clothes. By making ergonomic garments considering the characteristics of body shape, it can be expected to change the body shape due to the wearing of clothing that is not suitable for body shape and the effect on physical health in a positive direction.

• Korean Journal of Construction Engineering and Management
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• v.7 no.4 s.32
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• pp.61-68
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• 2006

Safety is the most important issue in the construction industry. Especially, work-related disease is increasing and resulted in lack of young workers and high turnover due to its 3D industrial image. The main objective of this paper is to identify the relationship of WRMSD with hand tools used in the building construction industry. In order to reach to the goals, the survey and interviews with laborers are conducted. The data is analyzed in a statistical manner. One of the interesting findings from the research is that the carpenters and steelworkers are the principal trade group suffering from WRMSD due to unsafe working condition and method. The results of the research will be used as the basis for the ergonomic design of the better construction working condition and hand tools.

• PNF and Movement
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• v.19 no.3
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• pp.391-399
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• 2021

Purpose: As laptop use increases throughout the COVID-19 pandemic and its use outside of traditional workstations proliferates, it is imperative to expand the limited research available regarding ergonomic exposure. This study aimed to identify the effects of a laptop supporter on biomechanical characteristics in the wrist joint muscles of healthy young adults. Methods: This was a cross-sectional observational study design with thirty-four healthy young adults as participants. They conducted a typing exercise performed under two different conditions, which were with and without a notebook computer supporter. This study measured the biomechanical characteristics of the muscles of the wrist joints including the flexor carpi ulnaris (FCU), the flexor carpi radialis (FCR), the extensor carpi radialis longus (ECRL), and the extensor carpi ulnaris (ECU). Measurements were taken three times: before typing, immediately after typing for 30 minutes with a supporter, and immediately after typing for 30 minutes without a supporter. The statistical method to compare the three different measurement conditions was the repeated measures ANOVA. Results: The participants showed significantly different levels of dynamic stiffness in both the FCU before typing and immediately after 30 minutes of typing with a supporter, and showed significantly different levels of dynamic stiffness in the FCR before typing and immediately after 30 minutes of typing with a supporter. The dynamic stiffness level immediately after 30 minutes of typing without a supporter was significantly different than that immediately after 30 minutes of typing with a supporter. However, the muscle tone was not significantly different among the three different conditions. Conclusion: The results of this study revealed that a laptop supporter used to correct the eye level of the electronic screen increases the dynamic stiffness of the wrist joint flexors, so it is necessary to consider the neutral position of the wrist joint during typing.

• Fashion & Textile Research Journal
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• v.21 no.3
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• pp.318-325
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• 2019

This study analyzes current self-nail tips and nail-tip satisfaction. The study method selected from 3 domestic and 3 overseas companies analyzed current self-nail tips based on brand recognition and sales rate. A questionnaire was conducted on 261 adult women in their 20s and 50s about the satisfaction of nail care and self-nail tips. The results are as follows. As a result to analyze the current nail tips, there were products that did not contain the type of nail tip or the composition and ingredients of the glue. An online survey of the sizes of the current nail tips indicated differences in the sizing system method and that the presented sizes are different. The response rate was the highest for the survey results on why self-nail tips were preferred for respondents who prefer self-nail tips because the price was cheap. The reason why they did not prefer self-nail tips was that the degree of completeness was lower and the fitness was not good. In addition, it showed a high response rate in that the adhesive strength was poor and the size did not fit the nails. Therefore, it is necessary to develop a size for nail types by ergonomic design and develop a self-nail tip that can reduce nail damage.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.7-15
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• 2018

We propose a method for evaluating sound quality quantitatively to develop high-level home appliances (HA). Generally, a refrigerator has diverse movable parts such as slider, drawer, and folding shelf. Therefore, an engineering treatment to control the noise quality is considered as one of key technologies for a higher level refrigerator. Among the movable parts, we have selected a folding shelf as an example, which is commonly setup inside of a home refrigerator for increasing space convenience, to control the noise quality. However, it is known that its noise level is very high comparing to other movable parts when folding or unfolding actions. In order to evaluate and compare the noise quality, we have tested different eighteen models, and have suggested an impact sound quality index (ISQI) based on subjective evaluation data obtained experimentally by thirty two evaluators. The ISQI was formulated using three sound quality elements (noise peak, raising time, impact duration) to determine psycho-acoustic properties. Through this work, we developed an evaluating process and ISQI that was verified the usefulness by comparing the test results of personal perceptions given by evaluators with the prediction value of ISQI. We showed a good relations between them, so we believe that the proposed method and ISQI can be utilized to control of the noise quality of HA effectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.170-176
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• 2018

Recently, weapon system requires personal protection products due to the explosion of rapid-fire explosion, which is considered to be multi threat in modernization, complication and war against terrorism. However, the conventional Korean military bullet protection helmets are not suitable for wearing convenience and combatant interoperability in terms of ergonomic. In this paper, we propose a suitable 3D Scanning method for the head, and compare the measured 3D dimension with the existing 2D measurement value to identity the reliability. Reverse engineered soldier head using the quick surface method was realized with a perfect free-form surface and satisfactory tolerance range (${\pm}0.2mm$). Through the comparison of 3D and 2D measured head dimensions, the absolute error value was 0.73 mm on average and relative error was 0.35 %, confirming the high accuracy of the 3D scan modeling. Also, quick surface method using 3D scanner is suggested a fast and accurate skill for ergonomics in obtaining the head modeling needed for military's personal bullet protection helmet design.

• Journal of the Korean Society of Safety
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• v.39 no.2
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• pp.75-86
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• 2024

Hydrogen has been selected as one of the key technologies for reducing CO₂ emissions to achieve carbon neutrality by 2050. However, hydrogen safety issues should be fully guaranteed before the commercial and widespread utilization of hydrogen. Here, a bow-tie risk assessment is conducted for the hydrogen fuel supply system in a gas turbine power plant, which can be a mass consumption application of hydrogen. The bow-tie program is utilized for a qualitative risk assessment, allowing the analysis of the causes and consequences according to the stages of accidents. This study proposed an advanced bow-tie method, which includes the barrier criticality matrix and visualized maps of quantitative risk reduction. It is based on evaluating the importance of numerous barriers for the extent of their impact. In addition, it emphasizes the prioritization and concentrated management of high-importance barriers. The radar chart of a bow tie allows the visual comparison of risk levels before/after the application of barriers (safety measures). The risk reduction methods are semi-quantitatively analyzed utilizing the criticality matrix and radar chart, and risk factors from multiple aspects are derived. For establishing a secure hydrogen fuel storage system, the improvements suggested by the bow-tie risk assessment results, such as 'Ergonomic equipment design to prevent human error' and 'Emergency shutdown system,' will enhance the safety level. It attempts to contribute to the development and enhancement of an efficient safety management system by suggesting a method of calculating the importance of barriers based on the bow-tie risk assessment.

• Journal of the Korean Society of Safety
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• v.20 no.2 s.70
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• pp.169-174
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• 2005

Traditionally, keyboards have been one of the most frequently used input devices for information processing using computers. As most computers adopt the Microsoft Windows for their operating system however, the usage of mouse has recently increased to a great extent. Moreover, the mouse has been used as the leading input device in such areas as industrial design and computer aided design. Excessive uses of mouse may cause a severe pain and fatigue on neck and upper limb due to the intensive and repetitive use of corresponding muscles, which renders a decline in efficiency and leads to musculoskeletal disorders. The main purpose of this study is to find the best working conditions to prevent musculoskeletal disorders when using mouse in a neutral posture. Utilizing electromyogram amplitude and Borg's scale, the role change and strength imposed on the muscles were measured and analyzed with and without the forearm support concerned. Also investigated were the effects of changes in elbow forearm supporter.

• Journal of Korean Medicine Rehabilitation
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• v.23 no.2
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• pp.95-104
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• 2013

Objectives : The purpose of this study is to analyze internal research trends of work-related musculoskeletal disorders(WMSDs) and provide problems of researches forward. Methods : 6 Korean databases were searched for articles of WMSDs published from 2000 to 2012, and 264 research were systematic reviewed. An analytical method was used descriptive statistics, an actual number and percentage. Results : The results of distribution by year were reported more than 20 articles after 2004, and 45 articles in 2009. Industrial classification distribution of research subjects the manufacturing industry was many most at the 84. Research contents in most description were 147 whether it was risk factor and relation. Research design type of articles was most description survey research 226. In the research field 89 articles were reported to the journal related to technologies. Conclusions : It is considered to be necessary that ergonomic approach would cooperate with other approaches such as integrated health management system as well as industrial medicine considering psychosocial factors.