• Journal of Korean Institute of Industrial Engineers
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• v.5 no.2
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• pp.21-36
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• 1979

Static muscle contractions when prolonged or frequently repeated result in discomfort, fatigue, and musculosketal injuries. An analytic and quantitative model has been developed in order to expand the working knowledge on muscle fatigue. In this paper, three Markov models of muscle fatigue are developed. These models are based on motor unit fatigue-recovery characteristics obtained from information on motor unit behavior as it relates to fatigue and graded exertions. Three successively more realistic models are developed that involve: (1) homogeneous motor units with intensity-dependent fatigue rates and state-independent recovery rates (the HMSI model); (2) homogeneous motor units, intensity-dependent fatigue rates and state-dependent recovery rates (the HMSD model); and (3) non-homogeneous motor units (i.e., Type S and Type F), intensity-dependent fatigue rates and state-dependent recovery rates (the HMSD model). The result indicate that a simple stochastic model provide a means to analyze the complex nature of muscle fatigue in sequential static exertions.

• IE interfaces
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• v.15 no.2
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• pp.107-113
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• 2002

Recent reports studied that injuries or deaths frequently occurred in consumer product accidents by product defects. Broadly speaking, product liability is liability which is imposed upon a manufacturer or other seller for personal injury, death, property damage and/or commercial loss arising with respect to a product or service provided by it. In this study, we want to search a method of prevention against appling PL laws. The way was researching on the level of appreciation of PL law, warning messages's means and design criteria for seller or consumer of child toys. As a result, most people didn't understand PL laws. Although they read them before purchasing child toy, many consumers didn't differentiate means of "Notice", "Warning", and "Danger" in warning messages. In addition, they considered important factors in warning messages as notice warning, safety mark(UL, etc), age recommendation and color in order. This study will be effective to search a method of prevention against PL laws.

• Journal of the Ergonomics Society of Korea
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• v.30 no.4
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• pp.535-540
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• 2011

Objective: The aim of this paper is to survey the gender differences Work-related musculoskeletal disorders among agriculture workers. Background: The number of occupational injuries has been decreasing trend in Korea, but it has been increasing in agriculture. The ratio of women worker shows steady increasing trend among the agricultural worker in Korea. Method: This study investigated through the questionnaire to 358 agricultural workers who are working for agriculture located in Gyeongnam, Gyeongbuk and Jeju. Results: The task types occurring frequently and the weight of a heavy object handled according to the sex were showed statistically significant difference. The estimation of WMSDs patients by sex appeared statistically very significant difference. Conclusion: The prevalence rate of WMSDs in female was about 21 percent higher than the prevalence rate of WMSDs in male. Application: The result of this study will help improvement of work environment and prevention of WMSDs in agricultural work.

• Journal of Industrial Technology
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• v.22 no.B
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• pp.45-50
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• 2002

Airbag systems have improved the occupant safety in reducing the injuries of driver and passenger during collisions. They have occasionally caused fatalities; especially to small occupant and children. Recent airbag related fatalities of children have raised serious concerns on how to evaluate the safety of children in various crash environments. This paper present the development of the 3-year-old human model. Child human model is composed of skin, skeleton and joints. The positions of joint and mass properties of body segments are calculated from ARB(Ariticulated Rigid Body) program GEBOD. To verify the developed human model, ROM simulation and OOP simulations are conducted.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.4
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• pp.46-53
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• 2002

Push-pull strength has been found to be associated with various work factors such as height, distance, repetition, duration, posture and individual factors. Therefore, this study was performed to investigate the effect of various work factors on push-pull strength and muscle recruitment pattern. Work factors were consisted of grip height(elbow, shoulder), grip distance(100%, 50%, and 25% of maximum grip distance) and shoulder angle(neutral($90^{\cire}$), and abduction($45^{\cire}$, $0^{\cire}$)) during sitting work. The results showed that the normalized strength and EMG value were higher at the elbow height than the shoulder height, and increased with grip distance and shoulder adduction. The results of ANOVA showed that there was significant difference on muscle recruitment patterns among the task conditions. Therefore, it is necessary to consider work factors as well as strength to prevent workers from work-related injuries.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.11 no.2
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• pp.15-29
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• 2007

In this paper, we explore some interesting models of the quasi-negative-binomial distribution based on difference differential equations applicable to theory of microorganisms and the situations like that. Some characterizations based on conditional distributions and damage process have been obtained. Further, the distribution of number of accidents as the quasi-negative-binomial distribution in the light of Irwin's theory of ";proneness-liability"; model has been derived. Finally, the proposed model (QNBD) has been applied to study the Shunting accidents, home injuries, and strikes in industries.

• Journal of the Korea Safety Management & Science
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• v.18 no.3
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• pp.81-89
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• 2016

Floor slipperiness is a leading cause in slip and fall accidents which are a major source of occupational injuries in Korea. Researchers have estimated the slip and fall related accidents rank number one or two in number of the injured. The objectives of this study were to find the field contamination effect and improvement countermeasure. Slipping and falling are common accidents in large public facilities, especially facility which vulnerable adults generally use as like hospital. So, we measured the coefficient of friction of several floors on the floor in hospital, under dry and wet using BOT-3000. The results of the coefficient of friction measurements showed that floor type and surface conditions were all significant factors affecting the coefficient of friction. The most surprising finding of this study was that there were significant friction improvement when the floors were properly cleaned with cleaning equipments.

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.897-905
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• 2010

The purpose of this study is to identify relationships between safety and health indices in a shipbuilding industry. From the results of periodical health examination, job stress test, and health questionnaire for musculoskeletal disorders, the author stratified the 704 shipbuilding workers into categories of smoking, drinking frequency, the amount of exercise per week, obesity, blood pressure, diabetic symptoms, liver function, audibility, job stress, fatigued condition, musculoskeletal symptom, and accident. The results show that occupational injuries are highly related to smoking, drinking frequency, auditory capacity, fatigued condition, and musculoskeletal symptoms. These results can be used to develop more effective accidental occupational injury prevention programs for shipbuilding industries.

• Journal of the Korea Safety Management & Science
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• v.4 no.3
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• pp.13-23
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• 2002

The use of industrial robots has been one of the most important innovations in production technology in recent years. It is true that robotic techniques, as applied to hazardous operation in industry, have reduced the risk of injury and occupational disease among workers. However, new types of occupational safety and health risks, associated with unpredictable motion patterns and erratic idle times and serious injuries and deaths have occurred due to operator misperception of these robot design and performance characteristics. This paper provides an overview of ergonomic and safety issues which are important in the design of robotic workspaces. Particularly, this study uses MORT(Management oversight and risk tree analysis)as the system's safety technique applied to robotics.

• International Journal of Automotive Technology
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• v.6 no.5
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• pp.491-499
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• 2005

There are different types of vehicle impacts recorded every year, resulting in many injuries and fatalities. The severity of these impacts depends on the aggressivety and incompatibility of vehicle-to-roadside hardware impacts. The aim of this paper is to investigate and to enhance crashworthiness in the case of full barrier impact using a new idea of crash improvement. Two different types of smart structures have been proposed to support the function of the existing vehicle. The work carried out in this paper includes developing and analyzing mathematical models of vehicle-to-barrier impact for the two types of smart structures. It is proven from analytical analysis that the mathematical models can be used in an effective way to give a quick insight of real life crashes. Moreover, it is shown that these models are valid and flexible, and can be useful in optimization studies.