손 힘 사용 측정 FSA 시스템의 성능 평가

정기효,유희천,권오채,Jung, Ki-Hyo,You, Hee-Cheon,Kwon, O-Chae 대한인간공학회 2005 大韓人間工學會誌 Vol.24 No.2

The FSA(Force Sensitive Application) system measures hand force by using force resistance sensors. Compared to conventional hand force measurement systems such as Lafayette hand dynamometer and Jamar hydraulic hand dynamometer, the FSA system can be applied to analyze use of hand forces while the hand is manipulating objects for a task, However, the measurement performance of the FSA system has not been objectively evaluated. The present study tested the FSA system in terms of stability, repeatability, accuracy, and linearity. It is shown that the FSA system has good stability (CV$\leq$0.02) and linearity($R^2$=0.82), but has low repeatability(CV=$0.11{\sim}0.19$) and accuracy(22% of underevaluation on average). This performance result indicates that measurements from the FSA system should be used for relative comparison rather than for absolute comparison.

앉은 자세에서 힘 수준에 따른 상지관절 동작별 최대 수용 반복 빈도수 분석

권오채,유희천,정기효,Kwon, O-Chae,You, Hee-Cheon,Jung, Ki-Hyo 대한인간공학회 2005 大韓人間工學會誌 Vol.24 No.2

Evaluation of repetitiveness for upper extremity intensive tasks is essential to determine the level of risk for upper extremity musculoskeletal disorders at the workplace. However, experimental data available to establish the acceptable levels of repetitiveness for various postures and forces is lacking. The present study examined the maximum acceptable frequencies(MAFs; motions/min.) of shoulder, elbow, wrist, and index finger motions at different forces(1kgf and 4kgf for shoulder, elbow, and wrist; 0.25kgf and 1 kgf for index finger) in sitting. Seventeen right-handed males in 20s without having any history musculoskeletal disorders participated in the MAF experiment. The participants determined their MAFs for the upper extremity motions by using the self-adjustment method and their work pulse(increase in heart rate; beats/min.) and rating of perceived exertion(RPE) were measured when working at MAF. The MAFs of elbow, wrist, and index finger motions for each force level were about 2, 3, and 6 times the corresponding MAF(9 at the high force and 24 at the low force) of shoulder motion and the MAFs at the low force increased about 2 times those at the high force. The work pulses of elbow, wrist, and index finger motions for each force level were 70%, 50%, and 30% of the corresponding work pulse(17 at the high force and 12 at the low force) of shoulder motion and the work pulses at the low force were about 70 % of those at the high force. Lastly, the RPEs of the upper extremity regions were about level 3(moderate) or below.

인체측정학적 설계를 위한 대표인체모델 생성 기법의 평가: 격자 기법

정기효,유희천,Jung, Ki-Hyo,You, Hee-Cheon 대한인간공학회 2007 大韓人間工學會誌 Vol.26 No.1

Representative human models (RHMs), a group of digital human models which represent the people of the target population within a designated percentage (e.g., 95%), are used for ergonomic design and evaluation in virtual environments. The present study evaluated the grid approach, a RHM generation method, in terms of accommodation percentage. RHMs generated from the grid approach dramatically decreased the accommodation percentage of the target population as the number of anthropometric dimensions under consideration increased. For example, the accommodation percentages by RHMs generated by the grid approach were 95% for 3 key dimensions (selected among 10 anthropometric dimensions), 45% for 5 dimensions, and 10% for 10 dimensions. A standardized multiple regression analysis found that this decreasing accommodation percentage was caused by low correlations between key dimensions and other dimensions. The accommodation evaluation process used in the present study is applicable to evaluation of other RHM generation methods.

Design Structure Matrix를 활용한 인체측정학적 제품설계 방법: 컴퓨터 워크스테이션 설계 적용

정기효,권오채,유희천,Jung, Ki-Hyo,Kwon, O-Chae,You, Hee-Cheon 대한인간공학회 2007 大韓人間工學會誌 Vol.26 No.3

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.

고령자 근효율 향상을 위한 피트니스 압박웨어 시장조사 및 동작특성 조사

전은진 ( Eun-jin Jeon ),유희천 ( Hee-cheon You ),김동미 ( Dong-mi Kim ),김희은 ( Hee-eun Kim ) 한국의류산업학회 2018 한국의류산업학회지 Vol.20 No.3

The objective of this study is to investigate the market of fitness compression wear as well as to design an optimal fitness compression wear by analyzing the muscle and movement characteristics of the elderly women in Korea. In this regard, research for functional garments is needed to increase muscle activity of elderly people during physical exercise. Firstly, we investigated the brand, design, size, material, and pattern of fitness wear based on the market survey. Secondly, we identified preference, evaluation items, evaluation method, and pattern design method based on the literature review. Finally, in addition, the motion type, range, angle to improve the muscle strength of the elderly were investigated and the maximum muscle strengths of each motion were analyzed by using 2007 Size Korea data (n = 386). It is also designed for muscle fatigue through exercise and rapid fatigue recovery after exercise. The evaluation methods for fitness compression wear were classified as motor functionality, physiological comfort, pattern and material suitability evaluations. The muscle strength at leg (pushing force) and waist (lifting force) of the ages of 60 to 69 years old showed 239.3 N and 274.5 N, respectively, which were the lowest forces compared to younger age groups. By applying these results to the design process of fitness wear, it is anticipated that the fitness wear will have a proper fit to the body shape of elderly people in South Korea as well as it can increase muscle efficiency to promote physical capability and healthy life for senior people.

PC기반 시야검사를 통한 효과적인 시선고정 유도방법 연구

이지형,이백희,박현지,최정한,유희천,강자헌,Ji Hyoung Lee,Baek Hee Lee,Hyun Ji Park,Jeong Han Choi,Hee Cheon You,Ja Heon Kang 대한안과학회 2013 대한안과학회지 Vol.54 No.9

Purpose: The present study explored novel methods in visual field tests that actively induce the gaze of the examinee to the fixation target in the center vision and compared their effectiveness. Methods: Four gaze induction methods (dot-on, dot-off, number-on, and number-off) were prepared by combining 2 types of fixation targets (dot and number) and 2 conditions of sound presence (on and off). The gaze induction methods were implemented to a PC-based visual field testing system and the 24-2 visual field testing protocol was administered to 14 participants without glaucoma. The performance of the gaze induction method was evaluated in terms of fixation error rate, target detection rate, and subjective satisfaction (7-point scale, 1 for least satisfied and 7 for most satisfied). Results: The fixation error rates of dot-on (5.7%) and number-on (6.4%) were relatively lower than the other methods; the target detection rates of the induction methods were very high (95-96%) without significant differences, and the subjective satisfaction levels of dot-on (5.7) and number-on (5.4) were significantly higher than the other methods. Conclusions: In the present study we determined number-on as the preferred effective gaze induction method compared to the conventional dot-off method when fixation error rates and subjective satisfaction were considered.

전과정평가를 통한 핸디형 청소기의 친환경적 디자인 개발

유택호 ( Taek Ho You ),이지형 ( Ji Hyung Lee ),유희천 ( Hee Cheon You ) 한국전과정평가학회 2014 한국전과정평가학회지 Vol.15 No.1

국가별 환경 규제 강화에 따라 환경친화적 제품설계에 대한 필요성이 증대되고 있다. 본 연구는 상용화된 핸디형 청소기 두 종의의 성능, 사용성, 전과정평가를 통해 비교하여 친환경적 제품 개선 전략을 수립하였다. 성능 평가는 흡입 범위, 흡입력, 소음 발생량, 전력량의 4가지 측면에서 평가하였다. 사용성 평가는 파지 적절 성, 청소 편의성, 충전 편의성 등 10가지 항목을 5점 척도(1점: 매우 불만족; 5점: 매우 만족)로 평가하였다. 마지막으로 에코디자인 프로세스를 활용한 전과정평가 수행 결과, 핸디형 청소기는 사용 단계에서 환경 영향이 가장 높은 것으로 파악되었다. 본 연구는 성능, 사용성, 전과정평가 결과를 활용하여 에너지 효율과 사용성 측면에서 핸디형 청소기의 친환경적 개선 방안을 제안하였다. 본 연구를 통해 제안된 개선 방안을 적용할 경우 핸디형 청소기의 탄소배출량을 약 8 kg·CO2-eq./EA 감소시킬 수 있을 것으로 예상된다. Needs for eco-friendly product design have increased as environmental regulations and public awareness have raised. The present study was performed to develop eco-friendly product design concepts by comparing performance, usability, and environmental impact assessments of two handy vacuum cleaners. Performance measurements of the vacuum cleaners such as suction area, suction power, noise, and electric power were collected. Usability assessments of the vacuum cleaners such as feeling of grip, easiness of cleaning, easiness of recharging were surveyed using a 5-point scale(1: very dissatisfied and 5: very satisfied). Finally, an LCA on the vacuum cleaners was performed, showing the use phase of vacuum cleaner had the highest environmental impact among the product life cycle stages. Eco-friendly product design concepts were proposed based on the assessment results of performance, usability, and LCA. The proposed eco-friendly product design concepts can reduce about 8 kg·CO2-eq./EA for handy vacuum cleaner.

기능성 의복의 인간공학적 평가 체계 개발 및 적용: 방염복의 평가 및 개선 대상 파악

조자영,정정림,연수민,장준호,유희천,김희은,Cho, Ja-Young,Jeong, Jung-Rim,Yeon, Soo-Min,Chang, Joon-Ho,You, Hee-Cheon,Kim, Hee-Eun 대한인간공학회 2007 大韓人間工學會誌 Vol.26 No.2

Ergonomic methods have been effectively applied to design and evaluation of functional clothing. The goals of the present study are to: (1) develop an ergonomic evaluation system for the systematic analysis of functional clothing and (2) examine the usefulness of the proposed evaluation system by applying to flame-proof clothing. Based on the survey of literature and the brainstorming of experts in clothing design and ergonomics, factors considered for clothing evaluation were selected, classified, and complemented, resulting in an ergonomic clothing evaluation system consisting of four factor categories (clothing construction, user, work and environment, and user response). Using the proposed system, a field survey and a laboratory experiment were conducted for flame-proof clothing to identify its design problems. The field survey to workers found a comprehensive set of problems on the flame-proof clothing design in terms of pattern, textile, and color. The laboratory experiment identified additional design problems using a questionnaire that was developed based on an analysis on the relationship between clothing design components and ergonomic evaluation measures. The present study showed the ergonomic evaluation system and the relationship analysis of clothing design components and ergonomic evaluation measures are of use to identify design problems of functional clothing in a comprehensive and analytic manner.

근골격계질환 예방관리 프로그램에 대한 구조 분석 및 실무자 요구 사항 조사

정기효,이상기,권오채,유희천,김대성,Jung, Ki-Hyo,Lee, Sang-Ki,Kwon, O-Chae,You, Hee-Cheon,Kim, Dae-Seong 대한인간공학회 2005 大韓人間工學會誌 Vol.24 No.3

The KOSHA codes H-31 and H-30 provide general guidelines to establish a prevention program for work-related musculoskeletal disorders(WMSD). Understanding of the components and practitioner needs for a WMSD prevention program is necessary for effective revision and implementation of the KOSHA codes. The present study established a comprehensive structure for a WMSD prevention program and surveyed practitioner needs for the KOSHA codes. The comprehensive prevention program structure, consisting of 7 parts(organization, education, risk management, medical management, program evaluation, and record keeping) and 90 items, was constructed by analyzing WMSD prevention guidelines published by various government agencies such as KOSHA, OSHA and NIOSH. Next, 20 practitioners, from four industry sectors(auto manufacturing, auto part manufacturing, shipbuilding, and machinery), working in a safety and health department or labor union, were interviewed to collect opinions for the KOSHA codes in terms of relevance, government support, and additional information needed. Guidelines of the KOSHA codes requiring modifications and government supports were identified, which can be used to revise the KOSHA codes and to establish a government policy to promote the implementation of the KOSHA codes. Lastly, the survey revealed that integrated, customized, quantitative, and case information for WMSD prevention is additionally needed, which can be used as design guidelines for a WMSD prevention program manual for practitioners.

손동작에 따른 손체표 길이 변화를 적용한 장갑 설계 평가

권오채,선미선,정기효,이민정,연수민,유희천,김희은,Kwon, O-Chae,Sun, Mee-Sun,Jung, Ki-Hyo,Lee, Min-Jeong,Yeon, Soo-Min,You, Hee-Cheon,Kim, Hee-Eun 대한인간공학회 2005 大韓人間工學會誌 Vol.24 No.4

Use of a glove made of materials with a low elasticity decreases the performance of the hand such as agility, dexterity, range of motion, and grip strength. The present study examined if the adverse effects of a low-elastic glove can be reduced by a design which accommodates the changes of hand surface lengths by hand motion. Two glove designs which provide patches of elastic cloth and pleats at the finger joints and knuckle were developed by considering the hand surface length changes, and then compared with two conditions(bare hand and conventional glove design that does not consider the dynamic characteristics of the hand dimensions) in terms of completion time in peg board insertion task, maximum grip strength, discomfort in hand motion, discomfort in force exertion, and overall discomfort by 24 right-handed participants. The test results confirmed that wearing of a glove significantly reduced the agility and grip strength capability of the hand and indicated that the novel designs were effective to lessen the performance decreases compared to the conventional design. Also, of the glove designs, the pleat glove design was found most preferred for both better hand performance and less subjective discomfort.