An Estimation Method of Representative Humanoids for Digital Human Simulation

Kihyo Jung 대한인간공학회 2013 大韓人間工學會誌 Vol.32 No.3

Objective: The present study developed an estimation method of boundary zone representative humanoids(hereafter, EBZ method) using descriptive statistics on the design target population. Background: The boundary zone method(hereafter, BZ method) generates representative humanoids at a boundary zone that statistically accommodates a designated percent of the design target population; however, the BZ method has a practical limitation because it requires a large scale anthropometric database on the design target population. Method: The EBZ method developed in the present study consisted of 3 steps. In the first step, the boundary zone of accommodating a designated percent(e.g., 90%) is formed under the assumption of normal distributions for anthropometric sizes. In the second step, cases that fall within the boundary zone are estimated using descriptive statistics(mean, standard deviation, and covariance) on the design target population. In the last step, K-mean cluster analysis is conducted for the cases, and representative humanoids are selected from each of clusters. Results: Evaluation results showed that mean accommodation percent of the EBZ method was 90.9%(range: 90.8~91.1%) which is similar to the target percent(90%). In addition, standard deviation of accommodation percent for 100 repetitions was 0.1%. Lastly, the number of representative humanoids generated by the EBZ method(n = 20) was similar to the BZ method(n = 16). Conclusion: The EBZ method can generate representative humanoids which accommodate a designated percent of the design target population using descriptive statistics. Application: The EBZ method can be utilized in the generation of humanoids for ergonomic design and evaluation of products when the large scale anthropometric database on the design target population is not existed.

Identification of the Minimum Legible Text Size for Group-View Display of the Main Control Room in Radioactive Waste Facility

Kihyo Jung,Baekhee Lee,Yoon Chang,Ilho Jung,Heecheon You 대한인간공학회 2017 大韓人間工學會誌 Vol.36 No.3

Objective:The present study identified the minimum legible text size by an experiment for eight combinations of background and text colors, which will be used in designing visual information on group-view display (GVD). Background: Information on minimum legible text size is needed to design the visual information presented on GVD in a radioactive waste control room. Method: The experiment was conducted for 22 male participants (age: mean = 37, SD = 6.7; visual acuity: over 0.8) who were recruited by considering demographic characteristics of current control room operators. Eight combinations of background and text colors were considered and the minimum legible text size was determined for each combination by applying the method of limits, one of psychophysical methods. Results: The minimum legible text size was significantly different in accordance with the combination of background and text colors. Statistical analysis results showed that luminance contrast and color contrast between background and text influenced the minimum legible text sizes. Conclusion: This study concluded that the minimum legible text size is 8 minute of arc for various combinations of background and text colors. Application: The minimum legible text size identified in the present study can be utilized in designing visual information on GVD at the main control room in a radioactive waste facility.

Evaluation of Information Presentation Methods for a Wearable Braille Display

Kihyo Jung,Minjeong Lee,Joonho Chang,Heecheon You 대한인간공학회 2011 大韓人間工學會誌 Vol.30 No.6

Objective: The present study evaluated information presentation methods applicable to a wearable Braille display in terms of performance and satisfaction measures. Background: A Braille display wearable at a finger can improve accessibility of information for the blind by presenting information in real time. Method: A Braille display with six pins operated by DC servomotors was developed to simulate four information presentation methods(active, stationary, simultaneous, and sequential methods). An evaluation experiment was conducted with 16 participants(8 normal and 8 blind participants) by using three objective measures(reaction time, RT, unit: sec; recognition time, CT, unit: sec; correct response percentage, CP) and two subjective measures(overall satisfaction, OS; perception easiness, PE) with a 7-point scale. Results: The average RTs and CTs of the active and stationary methods were significantly shorter than those of the simultaneous and sequential methods for the blind participants. Also, the average CPs, OSs, and PEs of the active and sequential methods were significantly higher than those of the stationary and simultaneous methods. Conclusion: The active and sequential methods were preferred to the other methods for the blind. Application: The performance characteristics identified in the present study for the four braille display methods can be utilized to develop an effective wearable Braille display system.

A Characteristic Analysis of Ergonomic Console Layout Studies Using Optimization Techniques

Kihyo Jung,Jaejung Kim,Taekho You,Baekhee Lee,Wonsup Lee,Seikwon Park,Woongseok Roh,Heecheon You 대한인간공학회 2012 大韓人間工學會誌 Vol.31 No.6

Objective: The present study systematically analyzed the characteristics of ergonomic layout optimization methods by a comprehensive literature survey. Background: Although layout design methods for ergonomic placement of controls and displays on a console have been developed, understanding of their characteristics is lacking. Method: The present study analyzed layout optimization papers published past 20 years from the following four aspects: optimization model, optimization algorithm, design principle, and constraint/assumption. Results: The existing layout optimization methods based on various optimization techniques consider only a partial set of four layout principles(importance, frequency of use, sequence of use, and functional grouping) and two ergonomic criteria(visibility and reach). In addition, the existing methods oversimplify components in various sizes, shapes, and angles by assuming the equality of the components in size and shape. Conclusion: A more effective layout optimization method is needed which considers the layout principles and ergonomic criteria in a comprehensive manner and reflect the diversity of components in size and shape. Application: The identified characteristics on the existing layout optimization methods can be applicable to development of a better ergonomic console layout design method.

대표 인체 모델 생성을 위한 주성분 공간의 대표점 결정 기법 개발

정기효(Kihyo Jung) 대한인간공학회 2018 大韓人間工學會誌 Vol.37 No.3

Objective: This study developed a determination method of representative points in the space of principal components to generate representative cases for anthropometric design and digital human simulation. Background: The advanced generation method using principal component analysis can create a group of representative cases that statistically accommodate a designated percentage of design target users. However, a specific determination method of representative points to generate representative cases has not been proposed in existing studies. Method: This study proposed a determination method of representative points on an n-dimensional ellipse formed in the space of principal components. The proposed method determined representative points on each principal component and on the combination of principal components using an optimization model. The performance of proposed method was evaluated by generating representative cases for anthropometric design and digital human simulation of airplane cockpit. Results: The proposed method selected eight representative points on an ellipse formed to accommodate 95% of design target users in the space of two principal components. The selected points represented one overall small user, two small users with different body proportion, two medium users with different body proportion, two large users with different body proportion, and one overall large user. Conclusion: The proposed method properly determined representative points on an ellipse in principal components. Application: The proposed method can be used to generate representative cases using principal component analysis for anthropometric design and digital human simulation.

혁신제품개발 교육과정 개발을 위한 전략수립 방법

정기효(Kihyo Jung),장준호(Junho Chang),이원섭(Wonsup Lee),장준호(Joonho Chang),유희천(Heecheon You),장수영(Soo Y. Chang),전치혁(Chihyuck Jun) 한국공학교육학회 2008 공학교육연구 Vol.11 No.3

기업에서는 경쟁력 제고를 위해 혁신제품개발 전문인력을 필요로 하나, 혁신제품개발 전문인력을 위한 대학의 교육과정 개설은 미흡한 실정이다. 본 연구는 대학에서 혁신제품개발 교과과정 개발을 위한 체계적 전략수립 방법을 제안하고 교육과정 개발에 적용하였다. 본 연구의 전략수립 방법은 순차적인 3 단계(전략요소 도출, 전략적 과제 수립, 전략실행 roadmap 수립)로 구성되어 체계적으로 교과과정 개발을 위한 전략을 수립할 수 있게 한다. 또한, 개발된 전략수립 방법은 P 대학의 “인간친화형 혁신제품 개발 모듈 교육과정” 개발 전략수립에 활용되었다.본 연구의 혁신제품개발 교육과정 개발 전략수립 방법은 제품개발 교육과정뿐만 아니라, 대학의 특성을 고려한 차별화된 신규 교육과정 개발에 유용하게 활용될 수 있을 것이다. Far greater than ever before is the present industrial demand for skilled professionals in innovative product design and development. Yet there is an apparent lack of a sufficient curricular provision for training design professionals in almost all engineering schools. The present study is to propose a systematic procedure for developing a strategy for building an innovative product design curriculum and demonstrate its application. The procedure consists of three major steps: strategic element derivation, task formulation, and task execution roadmap construction. The proposed procedure was applied to develop a modular curriculum (a cluster of several related courses) covering various subjects in relation to innovative product design and development. The procedure seems quite effective and useful for developing a curriculum that is strategically well differentiated based on the unique characteristics of a particular educational institute and its applicability seems not limited to a specific domain.

가상 환경 상의 헬리콥터 조종실 설계를 위한 정량적인 인간공학적 평가 방법 개발

정기효(Kihyo Jung),박장운(Jangwoon Park),이원섭(Wonsup Lee),강병길(Byunggil Kang),엄주호(Jooho Uem),박세권(Seikwon Park),유희천(Heecheon You) 대한인간공학회 2010 大韓人間工學會誌 Vol.29 No.2

For the development of a better product which fits to the target user population, physical workloads such as reach and visibility are evaluated using digital human simulation in the early stage of product development; however, ergonomic workload assessment mainly relies on visual observation of reach envelopes and view cones generated in a 3D graphic environment. The present study developed a quantitative assessment method of physical workload in a digital environment and applied to the evaluation of a Korean utility helicopter (KUH) cockpit design. The proposed assessment method quantified physical workloads for the target user population by applying a 3-step process and identified design features requiring improvement based on the quantified workload evaluation. The scores of physical workloads were quantified in terms of posture, reach, visibility, and clearance, and 5-point scales were defined for the evaluation measures by referring to existing studies. The postures of digital humanoids for a given task were estimated to have the minimal score of postural workload by finding all feasible postures that satisfy task constraints such as a contact between the tip of the index finger and a target point. The proposed assessment method was applied to evaluate the KUH cockpit design in the preliminary design stage and identified design features requiring improvement. The proposed assessment method can be utilized to ergonomic evaluation of product designs using digital human simulation.

헬리콥터 조종실 설계를 위한 헬리콥터 조종사 인체측정 및 분석

정기효(Kihyo Jung),조자영(Jayoung Jo),정정림(Jeongrim Jeong),박지은(Jieun Park),이원섭(Wonsup Lee),엄주호(Jooho Uem),이정효(Jounghyo Lee),강병길(Byunggil Kang),김희은(Heeeun Kim),박세권(Seikwon Park),유희천(Heecheon You) 대한인간공학회 2008 大韓人間工學會誌 Vol.27 No.4

To design the cockpit of Korean helicopter, anthropometric data for Korean helicopter pilots as a target population is necessary. The present study measured the body sizes of Korean helicopter pilots to design the cockpit of Korean helicopter, and compared the measurements with those of Korean civilian and the US Army. The sample size was 100 which determined by a statistical analysis. Anthropometric measurements were collected for 100 samples (male=94, female=6; age group=20~40) of Korean helicopter pilots by applying standard measurement protocol. To compare three anthropometric data, Korean civilian and US Army data were controlled by considering age group (20~40) and gender ratio (male: female=9:1) of Korean helicopter pilots. The average body sizes of Korean helicopter pilots were mostly similar to those of Korean civilian, however, lower limb related variables (hip breadth, popliteal height and thigh clearance) and shoulder-to-elbow length were significantly greater (1~7%) at a=0.05. Furthermore, the average body sizes for Korean helicopter pilots regarding lower limb length and thickness were significantly smaller than those of the US Army (1~12%); however, the average body sizes for Korean helicopter pilots regarding upper body related variables (sitting height, sitting eye height, and acromial height) and hip breadth were significantly greater (0.7~1.9%). Lastly, size variability for Korean helicopter pilots was significantly smaller than those of Korean civilian and the US Army. Anthropometric data for Korean helicopter pilots of the present study was applied to design and evaluate a Korean helicopter cockpit.

순위 기반 분기한정법과 군집분석을 활용한 인간공학적 콘솔 배치 최적화 방법 개발

정기효(Kihyo Jung),김재정(Jaejung Kim),이원섭(Wonsup Lee),유택호(Taekho You),이백희(Baekhee Lee),정진은(Jineun Jung),김기영(Kiyoung Kim),홍원기(Wongi Hong),최원범(Wonbeom Choi),박세권(Seikwon Park),장수영(Sooyoung Chang),유희천(Heecheon 대한산업공학회 2018 대한산업공학회지 Vol.44 No.3

주성분 기반 대표 인체 모델 생성을 위한 목표 비율의 사용자 수용 타원 생성 기법 개발

정기효(Kihyo Jung) 대한산업공학회 2018 대한산업공학회지 Vol.44 No.4