• 대한인간공학회지
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• 제1권2호
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• pp.3-9
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• 1982

This study demonstrates that certain personal and task factors can be modelled to predict slip potential as well as back loadings durings dynamic pushing and pulling tasks. Such tasks are com- mon to many manual material handling jobs in industry and the results of this work will hopefully be of use in improved job design. The objective of this research is to formulate and validate a dynamic biomechanical model of pushing and pulling a cart. For pushing and pulling tasks, the model can : (1) estimate foot forces for given hand forces, and (2) estimate tors muscle and vertabral column loadings. In order to formulate and validate the model, experiments involving pushing and pulling of a cart were performed. These experiments produced data of the following type : (1) dynamic forces on the feet, (2) hand forces required to move the cart, (3) body motions as functions of various cart motion and (4) back muscle actions. The model was validated using three different methods; precision was tested using correlation between predicted and measured results, accuracy using standard error between of predicted and measured results, and intuitive comparison of predicted results using sensitivity analyses.

• 동양고전연구
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• 제54호
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• pp.289-318
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• 2014

이 연구는 "무예도보통지"의 권법을 종합적인 관점에서 해석하는 것이다. 권법에 대한 인용서목 분석과 "기효신서", "무예제보번역속집", "무비지"의 권법 자세를 비교하는 목적이 있다. 문헌고찰을 통해 얻은 결론은 다음과 같다. 첫째, "무예도보통지" 권법의 인용서목을 검토한 결과, 중국문헌 14개, 한국문헌 2개 등 총 16개로 나타났다. 일본의 문헌은 권법 내용에 실리지 않았다. 중국의 대표적인 문헌으로는 "한서", "기효신서", "무비지" 등이었고, 한국의 대표적인 문헌으로는 "무예제보번역속집" 이었다. 둘째, 중국의 "기효신서", "무비지", 한국의 "무예제보번역속집", "무예도보통지" 등 4개의 문헌을 통해 나타난 동일한 자세는 현각허이세, 기고세, 안시측신세, 염주세, 포가세 등이었다. "기효신서"를 제외한 3개의 문헌에서는 정란, 귀축각, 지당세, 수두세, 신권, 일조편, 작지룡, 조양수 등 8개의 동일한 자세가 나타났다. "무비지"와 "무예도보통지"의 문헌에서만 보이는 동일한 자세로는 나찰의출문가자변하세, 금계독립세였다. 셋째, 권법 자세를 비교한 결과, 무엇보다 한국의 "무예제보번역속집"에서는 축천과 응쇄익이라는 독특한 자세가 나타났고, "무예도보통지"에서는 오화전신세와 갑을상부라는 독특한 동작이 나타났다. 문헌 연대로는 "기효신서"가 가장 빠르지만 기술특성을 고려할 때 "무예제보번역속집"과 "무예도보통지"에서 자세에 대한 변화가 점차 생기기 시작하였고, 무엇보다 조선 시대상에 맞는 독특한 자세들이 개발되기 시작하였다고 볼 수 있다. 종합적으로, "무예도보통지"의 권법은 "한서", "기효신서", "무비지"의 중국 문헌과 "무예제보번역속집"의 한국 문헌을 참고해서 집필되었다. 권법의 자세는 중국의 "기효신서", "무비지", 한국의 "무예제보번역속집", "무예도보통지"에서 5개의 동일한 동작 외에 다른 동작들은 점차 변화하였고, "무예제보번역속집"부터 8가지의 새로운 자세가 나타나기 시작하였고, 축천세와 응쇄익세의 2개 동작은 "무예제보번역속집"에만 나타났다. 특히 우리나라 권법은 축천세와 응쇄익세, 갑을상부, 오화전신세는 중국문헌의 권법 관련내용에서는 찾아볼 수 없는 새로운 기술들을 개발함으로써 점차 우리나라 실정에 맞게 변화를 꾀하였음을 알 수 있다. 이 연구의 의의는 조선시대 권법의 무술사적 의미를 해석하고 오늘날 맨손무예로 각광받고 있는 태권도의 전통주의적 관점에서 역사해석의 토대마련을 위한 징검다리를 놓았다는 점이다. 후속연구에서는 "무예도보통지"와 태권도의 기술에 대한 차이와 유사성 분석을 통해 태권도와 권법 사이에 관련성을 확인할 것이다.

• 한국운동역학회지
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• 제17권2호
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• pp.157-166
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• 2007

This study was to compare the major kinematic factors between the success and failure group on performing the back somersault motion in floor exercise. Three gymnasts(height : $167.3{\pm}2.88cm$, age : $22.0{\pm}1.0years$, body weight : $64.4{\pm}2.3kg$) were participated in this study. The kinematic data was recorded at 60Hz with four digital video camera. Two successful motions and failure motions for each subject were selected for three dimensional analysis. 1. Success Trail It was appear that success trail was larger than failure group in projection velocity, but success trail was smaller than failure trail in projection angle. Also it was appear that success trail was longer than failure group in the time required. Hand segment velocity and maximum velocity in success trail were larger than those in failure trail, and this result was increasing the projection velocity and finally increasing the vertical height of center of mass. At the take-off(event 2), flection amount of hip and knee joint angle was contributed to the optimal condition for the take-off and at the peak point, hip and knee joint angle was maximum flexed for reducing the moment of inertia. Also in this point, upper extremities of success trail extended more than those of failure trail. in this base, success trail in upward phase(p3) 2. Failure Trail It was appear that failure trail was smaller than success trail in projection velocity, but failure trail was larger than success trail in projection angle. Also it was appear that failure trail was more short than success trail in the time required. Hand segment velocity and maximum velocity in failure trail were smaller than those in success trail, and this result was reducing the projection velocity and finally reducing the vertical high of center of mass. At the take-off(event 2), flection amount of hip and knee joint angle wasn't contributed to the optimal condition for the take-off and at the peak point, hip and knee joint angle wasn't maximum flexed for reducing the moment of inertia. Also in this point, upper extremities of failure trail didn't extended more than those of success trail.

• Clinics in Orthopedic Surgery
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• 제10권4호
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• pp.468-478
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• 2018

Background: The restriction of wrist motion results in limited hand function, and the evaluation of the range of wrist motion is related to the evaluation of wrist function. To analyze and compare the wrist motion during four selected tasks, we developed a new desktop motion analysis system using the motion controller for a home video game console. Methods: Eighteen healthy, right-handed subjects performed 15 trials of selective tasks (dart throwing, hammering, circumduction, and winding thread on a reel) with both wrists. The signals of light-emitting diode markers attached to the hand and forearm were detected by the optic receptor in the motion controller. We compared the results between both wrists and between motions with similar motion paths. Results: The parameters (range of motion, offset, coupling, and orientations of the oblique plane) for wrist motion were not significantly different between both wrists, except for radioulnar deviation for hammering and the orientation for thread winding. In each wrist, the ranges for hammering were larger than those for dart throwing. The offsets and the orientations of the oblique plane were not significantly different between circumduction and thread winding. Conclusions: The results for the parameters of dart throwing, hammering, and circumduction of our motion analysis system using the motion controller were considerably similar to those of the previous studies with three-dimensional reconstruction with computed tomography, electrogoniometer, and motion capture system. Therefore, our system may be a cost-effective and simple method for wrist motion analysis.

• 재활복지공학회논문지
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• 제5권1호
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• pp.95-101
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• 2011

본 논문에서는 의수환자의 일상생활을 고려한 1-자유도 동작을 손을 쥐고 폄으로 정의하고, 두 동작에 대한 근전도 패턴 분류를 위한 가우시안 혼합 모델 기반의 근전도 패턴 분류 알고리즘을 제안한다. 근전도 패턴 분류 알고리즘의 핵심이 되는 근전도 신호의 특징점 추출을 위하여 근전 신호의 진폭 특성을 고려하는 절대차분평균치(DAMV)와 평균절대값(MAV)을 사용한다. 또한 동작에 대한 근전 신호의 진폭 특성을 보다 명확히 구분하기 위하여 D_DAMV와 D_MAV를 제안한다. 본 논문에서는 4명의 성인남성을 대상으로 실험을 실시하였고, 두 동작에 대한 근전도 패턴의 정확한 분류 여부를 확인하였다.

• 대한인간공학회지
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• 제22권3호
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• pp.75-91
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• 2003

Evaluation of repetitiveness for hand-intensive tasks is essential to determine the level of risk for upper-extremity musculoskeletal disorders at the workplace. Many measures and methods have been introduced for repetitiveness assessment: however, our understanding of the differences among these measures and methods is lacking. The present study compared the repetitiveness measures and measurement/analysis methods to help practitioners apply the proper repetitiveness assessment methodology in the workplace. By reviewing 51 studies of repetitiveness assessment, measures and corresponding measurement/analysis methods were surveyed. Of the repetitiveness measures, two types of dimensions (frequency and time) and corresponding types of analysis scopes were identified. According to the dimensional and analysis-scope types. the repetitiveness measures were categorized and then the surveyed studies were counted for each measure. It is identified that frequency measures have used 2.7 times higher than time measures and the frequency of wrist motions has been most frequently used in repetitiveness assessment. Furthermore, the measurement methods were categorized into objective and subjective methods, and the analysis methods into statistical and spectral methods. Lastly, eight factors (accuracy, reliability. sensitivity. efficiency. ease of use. applicability. interference. and robustness) were listed to be considered in selecting the appropriate assessment methodology.

• 대한인간공학회지
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• 제35권5호
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• pp.413-423
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• 2016

Objective:The aims of this study are to understand the effects of task (pushing, pulling, and clockwise and counter clockwise twisting) direction on the maximal output and their grip forces and to explore the relationship between the maximal output and the grip forces. Background: Knowing the normative maximal grip force is not enough to design a good hand tool. The industrial designers should understand the required grip forces in various motions toward a specific direction to make an effective and efficient hand tool. Method: Eighteen healthy volunteers participated in the series of isometric maximal output force tests. A custom-made force measuring equipment collected the output and the grip forces for three seconds. Force measurements along the vertical, coronal and sagittal axes were randomly repeated three times. Results: The pulling was strongest and the pushing was weakest in all directions. The effect of motion on the output forces varied in different directions. The corresponding grip force increased in the order of pushing, pulling, clockwise twisting, and counter clockwise twisting in all directions. The maximal output and their grip forces were highly correlated but the relationship was affected by motion and direction. The regression coefficient was greatest in pulling and smallest in clockwise twisting. Conclusion: The effect of motion on the output forces varied in different directions. The maximal output and their grip forces were correlated but the relationship was affected by motion and direction. Application: Findings of this study can be valuable information for industrial designers to develop more productive hand tools and work stations to help preventing the musculoskeletal disorders at work.

• International Journal of CAD/CAM
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• 제3권1_2호
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• pp.61-66
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• 2003

This paper describes a novel experiment that measures skin movement with respect to the flexional motion of a hand. The study was based on MR images in conjunction with CAD techniques. The MR images of the hand were captured in 3 different postures with surface markers. The surface markers attached to the skin where employed to trace skin movement during the flexional motion of the hand. After reconstructing 3D isosurfaces from the segmented MR images, the global registration was applied to the 3D models based on the particular bone shape of different postures. Skin movement was interpreted by measuring the centers of the surface markers in the registered models.

• 한국컴퓨터정보학회논문지
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• 제22권6호
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• pp.149-156
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• 2017

In this paper, we propose to enhance a Physical working conditions to decrease absence from work. we demonstrated the correlation of worker's absence with various environmental factors in workplace by surveying 6,962 workers. As result, first, concerning exposure to physical work factors, most of them complained of vibration, and concerning exposure to improper working posture, most of them complained of repetitive arm and hand motions. Second, the absence experience had correlations with age, monthly income, smoking, number of employees, long term working, and shift work, and of the physical factors, hand vibration, noise, high temperature, low temperature and improper working posture had correlations with physical pain posture, movement of people and carrying heavy materials. Third, experience of exposure to hand vibration, noise and low temperature of the physical factors had impact on absence, and of the improper working posture, physical pain posture and carrying heavy stuff had impacts on absence. Through this study, it was found that of the work factors of Korean workers, physical factors and improper working posture had impacts on absence. The results of this study confirmed that physical factors and inappropriate working posture among work factors influenced the absenteeism. Therefore, it is required to improve the work environment regarding physical risk factors and prepare a systematic management plan.

• 로봇학회논문지
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• 제17권4호
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• pp.484-492
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• 2022

This paper presents a simple and robust under-actuated robotic finger mechanism that enables self-adaptive grip, fingertip pinch, and caging grasp functions. In order to perform daily activities using hands, the fingers should be able to perform adaptive gripping and pinching motion, and the caging grasp function is required to realize natural gripping motions and improve grip reliability. However, general commercial prosthetic hands cannot implement all three functions because they use under-actuation mechanism and simple mechanical structure to achieve light-weight and high robustness characteristic. In this paper, new mechanism is proposed that maintains structural simplicity and implements all the three finger functions with simple one degree-of-freedom control through a combination of a four-bar linkage mechanism and a wire-driven mechanism. The basic structure and operating principle of the proposed finger mechanism were explained, and simulation and experiments using the prototype were conducted to verify the gripping performance of the proposed finger mechanism.