• 대한인간공학회지
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• 제27권2호
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• pp.49-57
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• 2008

This study aims to investigate the effect of handle angles of pliers on performance, wrist motion and subjective rating of satisfaction. An experiment was conducted, in which handle angle of pliers was used as independent variable and 14 subjects participated. Based on the literature survey, plier handles angled at 0$^{\circ}$, 10$^{\circ}$, 20$^{\circ}$, 30$^{\circ}$ and 40$^{\circ}$ were adopted in the experiment. The subjects were instructed to bend iron plates by 90$^{\circ}$ and to cut wires as soon as possible. The results revealed that 1) handle angles of pliers have significant effect on wrist motion and satisfaction(p<0.0001); 2) handle angles of pliers did not affect performance of completing tasks irrespective of types of tasks done in the study; 3) in the initial stage of windup, plier with handle angled at 20$^{\circ}$ produced the least wrist motion of deviation in task of bending iron plates, while plier with handle angled at 40$^{\circ}$ did in task of cutting wires; 4) degree of satisfaction was maximized when handle of pliers was bent by 20$^{\circ}$ in both tasks. On the basis of the results, it is recommended that handle of pliers be bent by 20-30$^{\circ}$ for reducing musculoskeletal disorders related to pliers.

• 한국안전학회지
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• 제23권1호
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• pp.51-56
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• 2008

This study aims to investigate the effect of handle angles of pliers on performances of task completion time and the number of errors, and subjective ratings of preference. For doing this, an experiment was conducted, where 14 subjects of 11 college-age male and three female students participated. In the experiment, plier handles angled at $0^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$, and $40^{\circ}$ were used as independent variable, and the task completion time and the number of errors, and subjective ratings of preference as dependent variables. The subjects were instructed to do two tasks of bending an iron plate by $90^{\circ}$ and cutting wires. The results revealed that while the performances of task completion time and the number of errors were not statistically different depending upon the handle angles of pliers, the subjective ratings of preference were significantly different. Based on the results, it is recommended that the pliers with handles bent by $20^{\circ}$ be used in real situations.

• 한국기계연구소 소보
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• 통권10호
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• pp.21-26
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• 1983

• 대한인간공학회지
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• 제33권6호
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• pp.553-563
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• 2014

Objective: The purpose of this study was to evaluate the effect of gender (male, female) and grip spans (45, 50, 60, 70, 80mm) on total grip strength, resultant force, finger force and subjective discomfort rating. Background: In order to prevent musculoskeletal disorders, studies of hand tools need to be preceded based on grip strength, finger force, and subjective discomfort rating. However, experimental apparatus using tools such as pliers that reflect the actual work place was almost non-existent. Method: Fifty-Two (26 males and 26 females) participants were recruited from the student population. In this study, a pair of revised pliers, which can change grip span from 45 to 80mm was applied to estimate total grip strength, resultant force and individual finger forces. All participants were asked to exert a maximum grip force with three repetitions, and to report the subjective discomfort rating for five grip spans of pliers (45, 50, 60, 70, 80mm). Results: There were significant differences of total grip strength, resultant force, individual finger forces and subjective discomfort rating according to grip span. The lowest total grip strength was obtained from the grip span of 80mm for both genders. For resultant force, the highest resultant force was exerted at grip spans of 50, 60 and 70mm for females and 50 and 60mm for males. The lowest subjective discomfort rating was observed in the 50mm for both genders. Conclusion: Based on the result, 50mm and 60mm grip spans which provide the highest force and lowest discomfort rating might be recommendable for the male and female pliers users. Application: The findings of this study can provide guidelines on designing a hand tool to help to reduce hand-related musculoskeletal disorders and obtain better performance.

• 대한인간공학회지
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• 제32권6호
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• pp.511-516
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• 2013

Objective: The objective of this study is designing an optimal hand tool through maximum grip force study accordance to the hand grip span. Background: In order to prevent musculoskeletal diseases, studies on hand tool design are proceeding based on grip strength, finger force, and contribution of individual finger force on total grip strength. However, experimental apparatus using a tool that is actually used in work place was almost non-existent. Method: 19 males were participated in an experiment. Using the load cell inserted real plier, finger force, grip strength, and subjective discomfort rate of both hands (dominant and non-dominant) were measured in 5 different hand grip span(45mm, 50mm, 60mm, 70mm, and 80mm). Results: There was significant difference(p<0.001) of total grip strength, individual finger force and subjective discomfort rating according to various hand grip span(45, 50, 60, 70, and 80mm). Also, statistically significant different(p<0.001) was shown between the dominant hand and non-dominant hand. In addition, individual finger force in maximum grip was in order of middle finger, ring finger, index finger, and little finger. Conclusion: Optimal grip span of pliers that exerting maximum grip strength is 50~60mm. Application: This finding is expected to be used for designing proper pliers.

• 대한인간공학회지
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• 제26권4호
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• pp.85-90
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• 2007

This study shows a way to develop ergonomic design of a plier through quality function deployment (QFD) approach. User needs for pliers, as well as the engineering characteristics which have influence on the ergonomic quality of pliers were determined from the interviews and questionnaires with various user groups. This information was entered in the house of quality, and the results show that the handle is the most important quality factor. A new model was proposed in which ergonomic and gender aspects were considered. QFD is considered a suitable method especially for the manufacturing and/or design fields where biomechanical or physiological background is not present.

• 수산해양기술연구
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• 제36권2호
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• pp.126-131
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• 2000

본 연구에서는 장어 통발어선 자동화 조업장치 개발의 첫 단계로서 통발을 모릿줄에 기계적으로 연결, 분리할 수 있는 장치인 집게식 통발연결장치 및 통발자동분리장치를 개발하여 해상성능실험을 실시하였다. 본 연구에서 얻어진 결과를 요약하면 다음과 같다. 1. 집게식 통발연결장치가 무른 꼬임 트와인 고다리 및 된 꼬임 트와인 고다리에 각각 연결되었을 때, 그 사이의 최대 인장하중은 각각 1379 N및 1,603 N 이었다. 2. 집게식 통발연결장치에 대한 해상성능시험 결과 성능이 양호함을 확인하였으며, 통발 회수율은 100% 이었다. 3. 통발자동분리장치에 대한 해상성능시험 결과 성능이 양호함을 확인하였으며, 통발 분리율은 100% 이었다.

• 대한인간공학회지
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• 제32권6호
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• pp.503-509
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• 2013

Objective: The purpose of this study is to analyze the individual finger force between dominant hand and non-dominant hand and to investigate an effect of the individual finger on the total grip strength depending on dominant hand and non-dominant hand. Background: Many studies on the ratio of the grip force between dominant hand and non-dominant hand has been researched. While a 10% rule which is a ratio of the grip force between dominant hand and non-dominant hand has been applied in most studies, studies on the rate of the individual finger force between dominant hand and non-dominant hand have been insufficiently researched. Method: The experiment was preceded with 17 subjects (male, mean 25.8 ages). The individual finger force and total grip strength were measured using pliers being able to change the grip span from 45 to 80mm. Results: The difference of total grip strength between dominant hand and non-dominant hand is following 10% rule. However, the difference of individual finger force between dominant hand and non-dominant hand are not same as the difference of total grip strength. Especially in the case of grip span with 50mm, the differences between total grip strength, index finger, middle finger, ring finger, and little finger were $9.87{\pm}14.80%$, $8.95{\pm}37.17%$, $13.71{\pm}28.27%$, $6.77{\pm}24.35%$, $39.29{\pm}42.46%$, respectively, with p=0.018 of statistical significance. Additionally, the results of regression analysis in 50 and 60mm of grip span showed that the difference in ring finger affected the most to the total grip strength; and the effects followed in order of index finger, middle finger, and little finger. Conclusion: Our study suggests that an effect of individual finger and grip span of pliers have to be considered when explaining the difference of the total grip strength between dominant hand and non-dominant hand. Application: This result is expected to be used for designing ergonomic hand tool.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.996-1001
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• 1991

We consider the object recognition of industrial tools which have one degree of freedom. In the case of pliers, the shape varies as the jaw angle varies. Thus, a feature vector made from the boundary image also varies along with the jaw angle. But a pattern recognizer should have the ability of classifying objects without any regards to the angle variation. For a pattern recognizer we have utilized a backpropagation neural net. Feature vectors were made from Fourier descriptors of boundary images by truncating the high frequency components, and they were used as inputs to the neural net for training and recognition. In our experiments, backpropagation neural net outperforms the minimum distance rule which is widely used in the pattern recognition. The performance comparison also made under noisy environments.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2003년도 추계학술대회
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• pp.173-183
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• 2003

The articles of food is very important things to human. Since PL Law came into effect in July of the last year(2002) in Korea, many domestic firms have taken great interests in PL. And the purpose of PL Law is to provide a means for those injured by defective products to receive redress. Additionally, enterprises get to place more importance on the safety of the products, which led to improvement in competitiveness and enhancement in quality. Consequently customers can get better products. So, it aims not only to compensate the injured by defective products but also to act an incentive to maker $s^pliers of food to make their products more safe. Therefore, this study was aiming to analyze the expected risks to articles of food after the enforcement of PL Law, and to establish a defending plan.an.