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

The principal component analysis based generation method of representative cases has been applied in anthropometric design and digital evaluation; however, it uses a trial and error method in generating an ellipse of enclosing a target percentage (e.g., 95%) of users. This study developed a new generation method of an ellipse that statically encompasses any target percentage of users in the space of principal components. The proposed method selected the users of a target percentage from a design target population by applying normalized square distances of anthropometric sizes and χ² distribution. Next, an optimization algorithm was applied for the selected users to find an ellipse of mathematically enclosing them with minimum area. This study evaluated percentages of users within the ellipses formed by the proposed method under various anthropometric design conditions. The evaluation results showed that the proposed method accurately generated ellipses that statistically accommodate 90.1 ± 0.07% (mean ± SE), 94.9 ± 0.06%, and 97.8 ± 0.05% for 90%, 95%, and 98% of target percentage.

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.

만족도 함수의 편향과 산포를 고려한 다중반응표면최적화 기법 개발

정기효(Kihyo Jung),이상기(Sangki Lee) 대한산업공학회 2012 대한산업공학회지 Vol.38 No.1

Desirability approaches have been proposed to find an optimum of multiple response problem. The existing desirability approaches use either of mean or min of individual desirability in aggregation of multiple responses. However, in order to find an optimum having high mean and low dispersion among individual desirability, the dispersion needs to be simultaneously considered with its mean. This study proposes bias and variance (BV) method which aggregates bias (ideal target-mean) and variance of individual desirability in multiple response optimization. The proposed BV method was applied to an example to evaluate its usefulness by comparing with existing methods. Evaluation results showed that the solution of BV method was a fairly good compared with DS (Derringer and Suich, 1980) and KL (Kim and Lin, 2000) methods. The BV method can be utilized to multiple response surface problems when decision makers want to find an optimum having high mean and low variance among responses.

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.

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.

적응형 유전알고리즘을 이용한 사용자 인터페이스 설계 방법 개발

정기효(Kihyo Jung) 대한산업공학회 2012 대한산업공학회지 Vol.38 No.3

The size and layout of user interface components need to be optimally designed in terms of reachability, visibility, clearance, and compatibility in order for efficient and effective use of products. The present study develops an ergonomic design method which optimizes the size and layout of user interface components using adaptive genetic algorithm. The developed design method determines a near-optimal design which maximizes the aggregated score of 4 ergonomic design criteria (reachability, visibility, clearance, and compatibility). The adaptive genetic algorithm used in the present study finds a near-optimum by automatically adjusting the key parameter (probability of mutation) of traditional genetic algorithm according to the characteristic of current solutions. Since the adaptive mechanism partially helps to overcome the local optimality problem, the probability of finding the near-optimum has been substantially improved. To evaluate the effectiveness of the developed design method, the present study applied it to the user interface design for a portable wireless communication radio.

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.

다양한 색상과 글꼴에 대한 한글의 식별 및 선호 크기 분석

정기효(Kihyo Jung) 대한산업공학회 2015 대한산업공학회지 Vol.41 No.1

A design guideline about legible and preferred Korean character sizes is necessary to provide better visual information in a group-view display. The present study examined the legible and preferred Korean character sizes by an experiment employing eight background-font colors and four representative font types (Gulim, Ming, Gothic, and Batang). Forty subjects (male : 20 and female : 20) in their 20s were recruited for the experiment. The legible and preferred sizes were determined based on the method of limits, one of psychological approaches. The results showed that the legible and preferred sizes increased as the contrast between background and font colors decreased. In addition, the legible and preferred sizes for Gulim were significantly smaller than those of the other font types. It is expected that the present study may contribute to providing better visual information in a group view display.

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

Designing an optimal component layout for an ergonomic console is important for the effective and efficient operation by its users. This study developed a console layout optimization method using a priority-based branch-and-bound algorithm and a clustering analysis. The proposed method starts with a priority-based branch and bound algorithm which searches all feasible layouts having scores higher than a designated score (e.g., 80 out of 100). Next, the objective function computes scores for the searched layouts by considering four allocation criteria (importance, frequency, sequence of use, and functional grouping) and two ergonomic criteria (reach and visibility). Lastly, the clustering analysis on the searched layouts extracts a small number of representative layouts for a designer to select the most preferred. The proposed layout optimization method was applied to component layout design of a radar console to examine its effectiveness.

크레인 안전인증기준에 대한 인간공학적 분석 및 개선

이용석,정기효,Lee, Yongseok,Jung, Kihyo 대한안전경영과학회 2021 대한안전경영과학회지 Vol.23 No.3

Crane is an important equipment for the transport of heavy goods in industrial sites, but it is also known as one of the most fatal machines. In order to reduce crane accidents, it is necessary to minimize human errors during crane operations. To achieve this, ergonomic design principles are recommended to be reflected from the crane design stage. The study analyzed the safety certification standards for crane that should be fulfilled at the crane design and manufacturing stage. This study selected five representative ergonomic design principles (feedback, compatibility, consistency, full-proof, and fail-safe) by surveying heuristic evaluation principles that are widely used for usability evaluation in early design stage. Next, the principles were applied to the safety certification standards to identify insufficient clauses. This study identified 12 insufficient clauses out of 119 in the current safety certification standards for crane and discussed their improvement directions to comply the ergonomic principles. The analysis results of this study can help of improving the safety certification standards and the method used in this study can also be applied to identify insufficient clauses in the safety certification standards for other industrial machines such as press machine and lift.