• 대한인간공학회지
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• 제30권5호
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• pp.597-603
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• 2011

Objective: The objective of this study was to compare one-hand and two-hands lifting activity in terms of biomechanical stress for the range of lifting heights from 10cm above floor level to knuckle height. Background: Even though two-hands lifting activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting are also very common at the industrial site and forestry and farming. Method: Eight male subjects were asked to perform lifting tasks using both a one-handed as well as a two-handed lifting technique. Trunk muscle electromyographic activity was recorded while the subjects performed the lifting tasks. This information was used as input to an EMG-assisted free-dynamic biomechanical model that predicted spinal loading in three dimensions. Results: It was shown that for the left-hand lifting tasks, the values of moment, lateral shear force, A-P shear force, and compressive force were increased by the average 43%, as the workload was increased twice from 7.5kg to 15.0kg. For the right-hand lifting task, these were increased by the average 34%. For the two-hands lifting tasks, these were increased by the average 25%. The lateral shear forces at L5/S1 of one-hand lifting tasks, notwithstanding the half of the workload of two-hands lifting tasks, were very high in the 300~317% of the one of two-hands lifting tasks. The moments at L5/S1 of one-hand lifting tasks were 126~166% of the one of two-hands lifting tasks. Conclusion: It is concluded that the effect of workload for one-hand lifting is greater than two-hands lifting. It can also be concluded that asymmetrical effect of one-hand lifting is much greater than workload effect. Application: The results of this study can be used to provide guidelines of recommended safe weights for tasks involved in one-hand lifting activity.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1996년도 추계학술대회논문집
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• pp.238-243
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• 1996

Grip strength is a very important basic data for ergonomic design of hand tools, grips, handles and etc.. Excessive grip strength is contineously exerted to handle the machines or tools, it might cause a musculoskeletal disorder such as cumulative trauma disorders. Capal tunnel syndrome is a typical nerve disorder anomg CTDs. In this paper we have measured the grip strength under sitting and standing posture for Korean adults ; 113 male and 105 female aged from 20' to the above 50' . And this paper performed statistical analysis for driving out characteristics between grip strength and anthropometric data. The results are as follows ; (1) The maximum girp strength is exerted under standing posture with the elbow in full extension(180 .deg. ) for both of male and female (2) There is significant difference in posture, sex and right left hand (3) Grip strength decreases with age for male, but it traces an inverted U curve for female (4) Grip strength has a correlation with age, weight, height, BSA, forearm length, hand length, thickness of wrist, circumference of wrist and breadth of wrist for male

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2930-2932
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• 2000

In this paper. a robust gesture recognition system is designed and implemented to explore the communication methods between human and computer. Hand gestures in the proposed approach are used to communicate with a computer for actions of a high degree of freedom. The user does not need to wear any cumbersome devices like cyber-gloves. No assumption is made on whether the user is wearing any ornaments and whether the user is using the left or right hand gestures. Image segmentation based upon the skin-color and a shape analysis based upon the invariant moments are combined. The features are extracted and used for input vectors to a radial basis function networks(RBFN). Our "Puppy" robot is employed as a testbed. Preliminary results on a set of gestures show recognition rates of about 87% on the a real-time implementation.

• Archives of Plastic Surgery
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• 제37권5호
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• pp.708-711
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• 2010

Purpose: The sheath of tendon is uncommon site of tuberculous involvement as compared to other parts of the body. Especially, tuberculous tenosynovitis affecting flexor tendon of the hand is a rare condition. In recent years, furthermore, the incidence of tuberculosis is increasing in our country. Tuberculous tenosynovitis is a chronic, slowly destructive disease, which is difficult to diagnosis before operation, but can be definitively diagnosed by the pathologic microscopic examination. Early detection and surgical excision combined with antituberculous medication is important. We report a rare case of tuberculous tenosynovitis of the flexor tendon of the hand. Method: A 12-year-old woman presented with a painless, nontender mass on palmar side between distal interphalangeal joint and proximal area of metacarpophalangeal joint of the left third finger. We had surgical excision of the involved flexor tendon sheath and studied histopathologically. Result: The histopathological findings were chronic granulomatous inflammation with caseating necrosis consistent with tuberculosis. We started antituberculous medication. Conclusion: Tuberculous tenosynovitis is a rare condition, especially involving on the flexor tendon of the hand. But because of increasing tendency of tuberculosis, it is important to differentiate it from other tumors of the hand.

• Journal of the Korean Statistical Society
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• 제32권3호
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• pp.311-311
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• 2003

This paper contains the following errors. 1. "$I_{\{x>D\}}{\lambda}dt_{p0}(t)s(x)$" should be added to the right hand side of (2.3). 2. "$I_{\{x>D\}}{\lambda}_{p0}(t)s(x)$" should be added to the right hand side of (2.6). 3. "$I_{\{x>D\}}{\lambda}_{p0}s(x)$" should be added to the right hand side of (2.9). 4. In Theorem 2.3 and its proof, "${\lambda}{\int}_{0}^{D}f(y)s(x-y)dy$" appears three times (including one in (2.20)). To each of these, "${\lambda}_{po}s(x)$" should be added. 5. In Remark 2.5, "${\lambda}dt_{p0}/s(x)dx" should be added to "${\int}_{0}^{D}{\lambda}dt\;s(x-y)dxf(y)dy$". As a result of these corrections, a simpler proof of Theorem 2.3 becomes available. Substituting (2.18), (2.21), (2.22) into the left hand side of (2.20) and comparing the result with (2.10), we have the right hand side of (2.20).

• The Journal of Korean Physical Therapy
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• 제31권3호
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• pp.157-160
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• 2019

Purpose: We compared the activation pattern of the mirror neurons (MN) between two types of hand movement according to action observation using functional MRI. Methods: Twelve right-handed healthy subjects (5 male and 7 female, mean age $21.92{\pm}2.02years$) participated in the experiment. During fMRI scanning, subjects underwent two different stimuli on the screen: 1) video clips showing repeated grasping and releasing of the ball via simple hand movement (SHM), and (2) video clips showing an actor performing a Purdue Pegboard test via complex hand movement (CHM). paired t-test in statistical parametric mapping (SPM) was used to compare the activation differences between the two types of hand movement. Results: CHM as compared with the SHM produced a higher blood oxygen level dependent (BOLD) signal response in the right superior frontal gyrus, left inferior and superior parietal lobules, and lingual gyrus. However, no greater BOLD signal response was found by SHM compared with CHM (FWE corrected, p<0.05). Conclusion: Our findings provided that the activation patterns for observation of SHM and CHM are different. CHM also elicited boarder or stronger activations in the brain, including inferior parietal lobule called the MN region.

• 산업경영시스템학회지
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• 제37권4호
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• pp.72-81
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• 2014

Even though two-hands lifting/lowering activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting/lowering are also very common at the industrial site, forestry, farming, and daily life. The objective of this study was to compare one-hand lowering activity to lifting activity in terms of biomechanical stress for the range of lowering heights from knuckle height to 10cm above floor level with two workload 7.5kg and 15.0kg. Eight male subjects with LMM were asked to perform lifting/lowering tasks using both a one-handed (left-hand and right-hand) as well as a two-handed technique. Spinal loading was estimated through an EMG-assisted free-dynamic biomechanical model. The biomechanical stress of one-hand lowering activity was shown to be 43% lower than that of one-hand lifting activity. It was claimed that the biomechanical stress for one-hand lifting/lowering activity is almost twice (194%) of the one for two-hands lifting/lowering activity. It was also found that biomechanical stress by one-hand lowering/lifting activity with the half workload of two-hands lowering/lifting activity was greater than that of the two-hands lowering/lifting activity. Therefore, it might be a risk to consider the RWL of one-hand lowering/lifting activity to simply be a half of the RWL of two-hands lowering/lifting activity recommended by NIOSH.

• 디지털융복합연구
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• 제11권7호
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• pp.157-163
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• 2013

본 논문에서는 손가락 마디 추정을 이용한 비전 및 깊이 정보 기반 손 인터페이스 방법을 제안한다. 먼저 비주얼 영상 및 깊이 정보 영상을 매핑한 후 왼손과 오른손의 영역의 레이블링 및 윤곽선 잡음 보정 후 각 손 영역에 대하여 손 중심점 및 회전각을 구현한다. 그리고 손 중심점에서 일정간격의 원을 확장하여 손 경계 교차점의 중간 지점을 계산하여 손가락 끝점과 마디를 추정하여 사용자의 손가락 동작을 인식한다. 본 방법을 실험한 결과 손의 회전 및 손가락 시작점 및 끝점을 정확하게 추정하여 다양한 손동작 인식 및 제어가 가능함을 보였다. 왼손과 오른손을 사용하여 다양한 손 포즈에 대해 실험한 결과, 본 논문의 제안 방법은 평균 90% 이상의 정확도로 초당 25프레임 이상의 처리 성능을 보였다. 제안 방법은 컴퓨터간의 HCI 제어, 게임, 교육 등의 비접촉식 인터페이스 응용분야에 적용될 수 있다.

• 대한인간공학회지
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• 제26권2호
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• pp.35-44
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• 2007

Work-related musculoskeletal disorders (WMSDs) are a major problem in industries in which manual materials handling is performed by workers. To prevent these WMSDs, it is necessary to understand the muscular strength capability and use this knowledge to design job and selection and assignment of workers. Even though two-hands lifting activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting are also very common at the industrial site and forestry and farming. However, a few researches have been done for one-hand lifting activity of manual materials handling tasks. The objective of this study is to compare one-hand and two-hands lifting strength in terms of static and dynamic strength of the lifting activity for the ranging from the height of knuckle to elbow. It is shown in this study that the isometric lifting strength of one-hand is ranging from 54.7 to 63.3% of the one of two-hands. However, it is found that there is no significant difference between a person's isometric lifting strength for left-hand and right-hand. It is also shown that there is no significant difference between the peak force under the dynamic sub-maximal loading with one-hand and two-hands lifting activity. Similar results were obtained for the peak acceleration and peak velocity under the dynamic sub-maximal loading with one-hand and two-hands lifting activity. Isometric lifting strength at the height of knuckle was ranging from 2 to 3 times of the dynamic peak force during sub-maximal lifting. It is concluded that the dynamic peak forces under the sub-maximal loading are not highly correlated with the isometric lifting strength in similar postures.

• 대한인간공학회지
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• 제32권5호
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• pp.413-420
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• 2013

Objective: The objective of this study was to compare one-hand and two-hands lowering activity in terms of biomechanical stress for the range of lowering heights from knuckle height to 10cm above floor level. Background: Even though two-hands lifting/lowering activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting/lowering are also very common at the industrial site and forestry and farming. Method: Eight male subjects were asked to perform lowering tasks using both a one-handed as well as a two-handed lowering technique. Trunk muscle electromyographic activity was recorded while the subjects performed the lowering tasks. This information was used as input to an EMG-assisted free-dynamic biomechanical model that predicted spinal loading in three dimensions. Results: It was shown that for the left-hand lowering tasks, the values of moment, lateral shear force, A-P shear force, and compressive force were increased by the average 6%, as the workload was increased twice from 7.5kg to 15kg. For the right-hand lowering task, these were increased by the average 17%. For the two-hands lowering tasks, these were increased by the average 14%. Conclusion: Even though the effect of workload on the biomechanical stress for both one-hand and two-hands lowering tasks is not so significant for the workload less than 15kg, it can be claimed that the biomechanical stress for one-hand lowering is greater than for two-hands lowering tasks. Therefore, it can be concluded that asymmetrical lowering posture would give greater influence on the biomechanical stress than the workload effect for one-hand lowering activity. Application: The result of this study may be used to provide guidelines of recommended safe weights for tasks involved in one-hand lowering activity.