• PNF and Movement
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• 제19권2호
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• pp.243-250
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• 2021

Purpose: The purpose of this study was to observe office workers' postural behaviors during computer work to identify the risk factors for head and thorax postural behaviors. Methods: The participants included 57 office workers who worked longer than 20 hours on a computer. Postural behaviors during computer work were measured using 3-D wearable motion sensors on the forehead and sternum. A multivariate linear regression model evaluated the association between various risk factors (neck pain, demographics, and environmental factors) and non-head and thorax postural behaviors. Results: The participants maintained their head and thorax in neutral postures (defined as 10° extension~10° flexion and 5° extension~10° flexion, respectively) for 24.7% and 39.3% of the total recorded time. Those who reported neck pain at the measurement of postural behaviors showed less time spent in thorax postures. Current neck pain, high desk height, and the distance between the keyboard and the edge of the desk (cm) were found to be related to less time spent in a neutral thorax posture. Conclusion: Office environment factors and current neck pain might affect workers' thorax postures, which might also determine the orientation of head postures during computer work.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제5권10호
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• pp.303-310
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• 2016

최근 Wii Sport나 Xbox Fitness 등 실제와 똑같이 몸을 움직이도록 하는 기능성 운동 게임인 엑서 게임이 인기를 끌고 있다. 그런데 이런 체감형 운동 게임에서는 사용자가 운동 자세를 얼마나 정확하게 취했는지 자세의 교정이 얼마나 필요한지를 알 수 있기 위하여 자세 인식이 크게 중요하다. 본 연구에서는 고령자를 대상으로 한 운동프로그램 콘텐츠에서 사용자의 자세 정보를 인식하기 위하여 키넥트 센서에서 제공하는 골격 모델의 특징점을 추출하여 각각의 특징벡터를 생성하여 만든 운동 자세 인식 모델 방법을 제안하였다. 본 논문에서는 제안하는 운동 자세 인식 모델의 설계 및 구현을 설명하였고, 간단한 실험을 통해서 제안된 운동 자세 인식 모델의 사용 가능성을 증명하였다. 실험결과 10명의 참여자들의 12가지 운동 자세에 대한 전체 평균은 94.52% 정도 일치율을 보였다.

• 대한인간공학회지
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• 제26권3호
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• pp.111-115
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• 2007

Design equations for anthropometric product design are developed by considering the geometrical relationships of design dimensions and anthropometric dimensions. The present study applied the design structure matrix (DSM) method to the development of design equations for a computer workstation, and compared design values from the design equations with corresponding design values of ergonomic recommendations and existing products. The relationships between design dimensions (e.g., legroom and worktable) were analyzed by a DSM, and then the application order of design equations (e.g., seatpan, backrest, armrest, legroom, and worktable in descending order) was determined. Next, design equations were developed by analyzing the geometric relationships between computer workstation design dimensions and anthropometric dimensions. Finally, design values for a computer workstation were determined by considering a standard posture defined and representative human models (5th, 50th, 95th %ile). The design values calculated using the design equations were similar with those of ergonomic recommendations found in literature and two commercial products measured in the study; however, some design values (e.g., seatpan height) were different due to discrepancy in standard posture. The DSM method would be utilized to systematically analyze the relationships between design dimensions for anthropometric product design.

• 대한정형도수물리치료학회지
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• 제25권2호
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• pp.57-64
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• 2019

Background: This study was designed to identify the effect of the taping on the forward head posture during computer work. Methods: Twenty healthy adults were statistically assigned into 2 groups, the taping group (n=10) and the control group (n=10). In order to induce delayed onset muscle soreness (DOMS), twenty subjects performed isometric exercise of the neck on Bobath table for 20 minutes. During the experiment, subjects in taping group were attached Kinesio-tape on their upper trapezius. By using 2-D motion analysis, measurements were taken before taping, at 24 hour, 48 hour, and 72 hour after inducing DOMS. The effects of taping were evaluated by the angle of the head. Results: The results of this study were as follows; 1) There was no significant difference between the taping group and the control group (p>.05). 2) The control group had no significance, but the taping group shown a significance on the angle of head during computer work (p<.01). The interaction of group x period also shown a significance (p<.01). Conclusion: From these result, it was revealed that the taping therapy on upper trapezius could improve the angle of head during computer work.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.1087-1104
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• 2015

An eye location based head posture recognition method is proposed in this paper. First, face is detected using skin color method, and eyebrow and eye areas are located based on gray gradient in face. Next, pupil circles are determined using edge detection circle method. Finally, head postures are recognized based on eye location information. The proposed method has high recognition precision and is robust for facial expressions and different head postures, and can be used in mouse operation. The experimental results reveal the validity of proposed method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.3-8
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• 2002

An intelligent polishing robot automation system is developed. Automatic Tool Change System(A.T.C.), Tool Posture Angle Control, and Robot Program for Polishing Application are developed and integrated into a robotic system that consists of a robot, pneumatic finding tool, and finding abrasives (papers and special films). A.T.C. is specifically designed to exchange whole grinding tool set for complete unmanned operation. Tool Posture Angle Control is developed to give a certain skew angle rather than right angle to tools on the surface for best finishing results. A.T.C. and Tool Posture Angle Control is controlled by a PC and the robot controller. Also, there have been some considerations on enhancing the performance of the system. Some elastic material is inserted between the grinding pad and the holder for better grinding contact. The robot path data is generated automatically from the NC data of previous machining process.

• International Journal of Precision Engineering and Manufacturing
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• 제6권3호
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• pp.37-44
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• 2005

Gait control capacity for most trans-femoral prostheses is significantly different from that of a normal person, and training is required for a long period of time in order for a patient to walk properly. People become easily tired when wearing a prosthesis or orthosis for a long period typically because the gait angle cannot be smoothly adjusted during wearing. Therefore, to improve the gait control problems of a trans-femoral prosthesis, the proper gait angle is estimated through surface EMG(electromyogram) signals on a normal leg, then the gait posture which the trans-femoral prosthesis should take is calculated in the neural network, which learns the gait kinetics on the basis of the normal leg's gait angle. Based on this predicted angle, a postural control method is proposed and tested adaptively following the patient's gait habit based on the predicted angle. In this study, the gait angle prediction showed accuracy of over $97\%$, and the posture control capacity of over $90\%$.

• Physical Therapy Rehabilitation Science
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• 제6권4호
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• pp.208-213
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• 2017

Objective: Despite reliable evidence of abnormal scapular motions increases, there is not yet sufficient evidence of abnormal humeral translations. This study aims to analyze the motion of the humeral head toward the scapula when the shoulder is actively abducted using the C-arm. Design: A case report. Methods: The participant was a healthy man without any limitation and pain during shoulder movement. The participant's shoulder was abducted; this movement in the frontal plane was measured using a C-arm (anterior-posterior view) and was analyzed with computer-aided design. The starting posture was $15^{\circ}$, and as the participant abducted his shoulder measurements were taken and analyzed at $30^{\circ}$, $60^{\circ}$, $90^{\circ}$, $120^{\circ}$, $150^{\circ}$, and ending at $165^{\circ}$. A line was drawn perpendicularly to the line connecting the humeral head axis to the glenoid, and another line was drawn perpendiculary to the line connecting the scapular axis to the glenoid. The distance between the two lines measured is defined as the e value. Results: At the starting posture ($15^{\circ}$), the central axis of the humeral head was located 1.92 mm inferior to the central axis of the scapula. The humeral head was superiorly translated from the starting posture to $120^{\circ}$, and then, showed an inferior translation to the ending posture ($165^{\circ}$). Conclusions: The results of this study showed that the humeral head moved upward from the starting posture ($15^{\circ}$) up to $120^{\circ}$ indicating, superior translation, and it moved downward when the posture was past $120^{\circ}$, indicating inferior translation.

• 한국전문물리치료학회지
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• 제9권3호
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• pp.113-124
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• 2002

The objectives of this study was to investiage the effects of sitting posture on carpal tunnel syndrome. Carpal tunnel syndrome (CTS) continues to be one of the most widely publicized maladies of the cumulative trauma disorder. Many studies have reported a positive association between CTS and highly repetitive work, high force, and poor posture. High force and repetitive work have especially been associated with CTS, but the evidence for work being a primary cause of CTS is strongest when these factors are combined. In addition to carpal tunnel syndrome, hand, wrist, and other disorders are attributed to these work-related movements. Such disorders are referred to as repetitive stress injuries, cumulative trauma disorder, overuse syndromes, and chronic upper limb pain syndrome. Incorrect posture also may play a role in the development of CTS in people who work at a computer and other types of keyboards. The tendency to roll the shoulders forward, round the lower back, and thrust the chin forward can shorten the neck and shoulder muscles, compressing nerves in the neck. This, in turn, can affect the wrist, fingers, and hand. The treatment and prevention of carpal tunnel syndrome continue to be approached with a segmental view of the human body. For example, the most common ergonomic solution for carpal tunnel syndrome associated with keyboard use is to keep the wrists in a neutral position by using a wrist rest in front of the keyboard and good sitting posture.

• 한국항행학회논문지
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• 제26권4호
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• pp.235-243
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• 2022

본 논문에서는 관성 항법 시스템 (INS)의 경우, 수직편향 (DOV)으로 인한 초기정렬에서의 자세 추정 오차를 분석한다. INS의 속도 및 자세 오차를 기반으로 DOV로 인한 자세 추정 오차를 이론적으로 분석하였다. 이론적 분석을 검증하기 위한 시뮬레이션을 수행했으며 결과는 이론적 분석과 잘 일치했다. 일례로 η=20"일 경우 정렬오차는 ϕ_N=0.00287°, ϕ_U=0.00196°가발생하며, 𝜉=20"일 경우에는 ϕ_E= -0.00286°의 오차가 발생하였다. 이를 통해 INS 자세오차의 결합특성으로 DOV에 기인한 수직 자세오차가 발생함을 확인하였다. 기존의 INS 정렬에서는 고려하지 않았던 DOV로 인해 추가로 자세오차가 발생할 수 있음을 보여 주었으며 이는 고정밀 INS 적용시에 DOV에 대한 보정을 반드시 고려해야 함을 의미한다.