• 반도체디스플레이기술학회지
• /
• 제21권2호
• /
• pp.117-122
• /
• 2022

This paper proposes a method for evaluating the work of manufacturing workers using MediaPipe as a risk factor for musculoskeletal diseases. Recently, musculoskeletal disorders (MSDs) caused by repeated working attitudes in industrial sites have emerged as one of the biggest problems in the industrial health field while increasing public interest. The Korea Occupational Safety and Health Agency presents tools such as NIOSH Lifting Equations (NIOSH), OWAS (Ovako Working-posture Analysis System), Rapid Upper Limb Assessment (RULA), and Rapid Entertainment Assessment (REBA) as ways to quantitatively calculate the risk of musculoskeletal diseases that can occur due to workers' repeated working attitudes. To compensate for these shortcomings, the system proposed in this study obtains the position of the joint by estimating the posture of the worker using the posture estimation learning model of MediaPipe. The position of the joint is calculated using inverse kinetics to obtain an angle and substitute it into the REBA equation to calculate the load level of the working posture. The calculated result was compared to the expert's image-based REBA evaluation result, and if there was a result with a large error, feedback was conducted with the expert again.

• 전기학회논문지
• /
• 제60권8호
• /
• pp.1577-1585
• /
• 2011

This paper proposes a posture stabilization control algorithm for a wheeled mobile robot using hybrid visual servo control method with a position based and an image based visual servoing (PBVS and IBVS). To overcome chattering phenomena which were shown in the previous researches using a simple switching function based on a threshold, the proposed hybrid visual servo control law introduces the fusion function based on a blending function. Then, the chattering problem and rapid motion of the mobile robot can be eliminated. Also, we consider the nonlinearity of the wheeled mobile robot unlike the previous visual servo control laws using linear control methods to improve the performances of the visual servo control law. The proposed posture stabilization control law using hybrid visual servoing is verified by a theoretical analysis and simulation and experimental results.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
• /
• pp.301-303
• /
• 2001

This paper deals with the biped robot gait on changing the initial postures. Gait of a biped robot depends on the constraints of mechanical kinematics and initial posture. Also biped robot's dynamic walking stability is investigated by ZMP(Zero Moment Point). The path trajectory. with the knee joint bent like a human, is generated and applied with the above considerations. To decrease trajectory tracking error, in this paper, a new initial posture similar to bird's case is proposed and realized with the real robot.

• 턱관절균형의학회지
• /
• 제2권1호
• /
• pp.13-16
• /
• 2012

Objectives: The quadrant theorem is a theorem proposed by C. M. Guzay in the field of functional, holistic dentistry. There are not much of scientific literature on the quadrant theorem. This study briefly reviewed basic concepts of quadrant theorem. Methods: A publication by Guzay and research articles were searched and reviewed. The quadrant theorem is depicted as a series of illustrations and accompanied explanations. Results: The primary concept of the quadrant theorem was presented in 1952. Based on geometric biophysics of the occlusion and related anatomical functions, physiological pivotal axis of the mandible is analyzed to occurs at the dens (the sub-atlas area). Composite muscular activity links the mandibular posture with C1-C2, which is then linked with the spinal posture. Twenty illustrations are progressively presented on the physiognomy, occlusion, and analysis of anatomical functions. The balanced distribution of the forces gives the durability of the functions in life. Conclusions: The quadrant theorem provides a functional linkage between the mandibular posture and the upper cervical vertebrae.

• 제어로봇시스템학회논문지
• /
• 제8권10호
• /
• pp.890-897
• /
• 2002

This paper deals with the reduction of trajectory tracking error by changing the initial postures of a biped robot. Gait of a biped robot depends on the constraints of mechanical kinematics and the initial states including the posture. Also the dynamic walking stability in a biped robot system is analyzed by zero moment point(ZMP) among the stabilization indices. Path trajectory, in which knee joint is bent forward like human's cases, is applied to most cases considered with above conditions. A new initial posture, which is similar to bird's gait, is proposed to decrease trajectory tracking error and it is verified through real experimental results.

• 한국경영과학회:학술대회논문집
• /
• 대한산업공학회/한국경영과학회 1990년도 춘계공동학술대회논문집; 한국과학기술원; 28 Apr. 1990
• /
• pp.151-162
• /
• 1990

Occupational disease among typists such as Carpal Tunnel Syndrome(CTS) and tendonitis has increased along with rapid expansion of office automation. During typing, the posture can be defined as forearm pronation, ulnar abduction, wrist extension and finger flexion. The CTS results from awkward posture between forearm-wrist-hand and the keyboard arrangement. Therefore, ergonomic principles should be emphasized in keyboard design. The objective of the study is to improve keyboard design by analyzing anatomical posture of forearm and hand during typing. An experimental study was performed to investigate relationships between a keyboard and typing performance. Results showed that typing performance is dependent to angles and slopes of a keyboard. Statistical analysis indicated that the suggested ergonomic keyboard improved typing speed significantly(17%).

• 대한인간공학회지
• /
• 제15권2호
• /
• pp.177-184
• /
• 1996

In light-weight hand tools, static posture may result in postural fatigue. Psotural tremor of the upper extremity in a static posture was measured to provide guidelines for hand tool weight. Postural tremor was measured on five levels of tool weitht : no weight, 400g, 800g, 1200g, and 1600g. Three types of camcorder recording postures were selected. For each condition, postural tremor was measured together with ENG of biceps, deltoid and pectoralis major, and Borg's CR-20 ratings of perceved exertion. Results of the experiment are as follows : frequency analysis of tremor revealed increased amplitude of frequency bands of 2-4Hz and 10-14Hz. Postural tremor of the upper extremeity maintained the initial level until fatigue developed. After the development of fatigue, the rate of change of postural tremor significantly increased. Different tool weights and hand postures showed different rates of tremor increase. Time tp fatigue and corresaponding endurance time were positively correlated with Borg's RPE scores.

• 한국안전학회지
• /
• 제14권4호
• /
• pp.192-198
• /
• 1999

Work-related musculoskeletal disorders constitute a major source of employee disability and lost wages. Cumulative Trauma Disorders(CTD) refers to a category of physical conditions which result from chronic musculoskeletal injury. Assessment of CTD risk in industry at early stage allows for early control, a safe environment, and a healthier workforce. In this study, the physical load of the shipping work in the cold storage warehouse were especially investigated. Employees were working with almost unnatural posture in a very restricted work space. The questionnaire and biomechanical analysis were used to evaluate the physical load. Results from analyses showed that they were sufficiently exposed to CTD due to repetition and unnatural posture. Based on the analysis, ways for improving working conditions are proposed. The analysis and proposals in this paper will serve as a basic tool for designing/redesigning working environment such as improvement of tools and equipments, design of times for work/rest cycle.

• 치위생과학회지
• /
• 제12권4호
• /
• pp.437-442
• /
• 2012

이 연구는 20명의 치위생과 학생들을 대상으로 스켈링 실습 시 발현되는 근육들의 활성도와 통증부위를 파악하여 치과위생사의 작업자세에 따른 기초자료를 제시하고자 연구를 실시하였다. 스켈링 시 근활성도의 측정은 free EMG를 이용하였고, 근골격계 통증부위를 알아보기 위해 Nordicstyle 설문지를 이용하여 측정된 연구결과는 다음과 같다. 1. 자세에 따른 스켈링 시 통증의 발현은 팔꿈치, 등, 다리, 무릎, 발목/발은 그룹간에 차이가 없는 것으로 나타났으나 목, 어깨, 손목/손, 허리에서는 자세에 따라 통증의 정도 차이가 높게 나타났다. 2. 자세에 따른 근활성도를 측정한 결과 올바른 자세를 가진 그룹에서는 시간의 경과에 따라 상승모근과 상완요골근에서 변화를 보였고, 나쁜 자세를 가진 그룹에서는 후두부근, 상승모근, 상완요골근에서 근활성도가 높게 나타났다. 3. 근활성도에서 두 군간의 변화양상은 좋은 자세로 스켈링을 실시한 그룹에서는 낮은 근활성도를 보였으나, 나쁜자세로 스켈링을 실시한 그룹에서는 근활성도가 과하게 증가되었다. 따라서 올바른 자세를 유지하며 스켈링을 실시하는 것이 근육의 활성을 효과적으로 사용하는데 도움이 되었음을 알수 있었고, 앞으로 임상에서 근무하는 치과위생사를 대상으로 연구를 실시하여 직무 효율성을 높이는 것이 필요하리라 생각된다.

• 한국의류학회지
• /
• 제34권6호
• /
• pp.955-968
• /
• 2010

Three-dimensional body data has been used in many industry fields including the apparel industry. This research used data from a study of the changes in lower body girth measurements from a 3D scan study of 25 female subjects aged 18 to 24 in four postures; a standing posture, a $120^{\circ}$ knee bend posture, a one pace stepping posture, and a sitting posture with a $90^{\circ}$ knee bend. We used the information on the difference between standing and seated measurements to adjust ease values for pants patterns an evaluation of the appearance, and the comfort of the pants. Waist girth in the sitting posture increased 8% compared to a standing posture and the hip girth measurement increased 7%. A basic pants pattern (pants A) with 2.4cm ease at the waist and 2.6cm ease at the hip was developed and a pants pattern (pants B) was developed using the rates of lower body girth change with a 5.7cm ease (8% change) at the waist and 7cm ease (7% change) at the hip. The appearance assessment items of pants A in a standing posture were higher than pants B. On the other hand, most appearance assessment items of pants B in a sitting posture were higher than pants A, especially the ease of pants back waistline and the appearance of the whole back. Comfort assessment items of pants B in both standing and sitting postures were higher than the comfort assessment items for pants A, especially the location of pants waistline, the ease of pants at the waistline, and the ease at the abdomen. In order to find the best level of ease for better appearance and comfort in both standing and sitting postures, 20 pants were constructed with ease values at the waist and hip in increments of 1.1cm in the range between the ease values of pants A and pants B. A fit test was conducted to compare the average appearance and comfort ratings that identified the pants with the best ease values at the waist and hip. The highest total mean was achieved in the pants with a waist ease of 4.6cm and hip ease of 4.8cm.