• 복식문화연구
• /
• 제30권4호
• /
• pp.495-512
• /
• 2022

This study aims to design a new sizing system for hygienic masks to protect against COVID-19-related respiratory disorders. The product sizes were collected from 70 commercially available hygienic masks, and 18 head measurements were obtained from the three-dimensional (3D) scan data of 2,048 men and women aged 20 to 69 years from the 6th Size Korea Survey. The statistical analysis was performed using the IBM Statistical Package for the Social Sciences (SPSS) 28.0 program. The "bitragion-subnasale arc" and "menton-sellion length" were chosen as the key body dimensions for the hygienic mask sizing system. The linear regressions with 18 3D head measurements were analyzed, and it was determined that the key body dimensions were useful for statistically predicting other 3D head measurements related to hygienic masks. A new sizing system was proposed for two types of masks, "masks with a tight fit" and "masks with a loose fit," taking into account the existing Korean Industrial Standards (KS) and the shortcomings of the sizes of hygienic masks on the market. The sizing system for tight-fitting masks consisted of the key body dimensions, with their sizes indicated by a pair of numbers. The sizing system for loose-fitting masks consisted solely of the bitragion-subnasale arc, with their sizes denoted by letters such as S, M, and L (denoting small, medium, and large, respectively). Future studies should consider this mask sizing system for different age groups, such as children and adolescents.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 1996년도 춘계학술대회논문집; 부산수산대학교, 10 May 1996
• /
• pp.125-129
• /
• 1996

This paper deals with the problem of placement/sizing of distributed piezo actuators to achieve the control objective of vibration suppression. Using the mean square response as a performance index in optimization, we obtain optimal placement and sizing of the actuator. The use of genetic algorithms as a technique for solving optimization problems of placement and sizing is explored. Genetic algorithms are also used for the control strategy. The analysis of the system and response moment equations are carried out by using the Fokker-Planck equation. This paper presents the design and analysis of an active controller and optimal placement/sizing of distributed piezo actuators based on genetic algorithms for a flexible structure under random disturbance, shows numerical example and the result.

• Structural Engineering and Mechanics
• /
• 제62권5호
• /
• pp.537-550
• /
• 2017

Structural sizing is a rewarding task due to its non-convex constrained nature in the design space. In order to provide both global exploration and proper search refinement, a hybrid method is developed here based on outstanding features of Evolutionary Computing and Teaching-Learning-Based Optimization. The new method introduces an observer phase for memory exploitation in addition to vector-sum movements in the original teacher and learner phases. Proper integer coding is suited and applied for structural size optimization together with a fly-to-boundary technique and an elitism strategy. Performance of the proposed method is further evaluated treating a number of truss examples compared with teaching-learning-based optimization. The results show enhanced capability of the method in efficient and stable convergence toward the optimum and effective capturing of high quality solutions in discrete structural sizing problems.

• 대한가정학회지
• /
• 제43권1호
• /
• pp.105-113
• /
• 2005

The purpose of this study was to suggest a standard sizing system for college female students' head wears according to their head types. The subjects were 193 college women, of 20 to 25 years-old. The subjects were directly measured anthropometrically and indirectly analyzed photographically. In previous tudy (Lim, 2004), 3 clusters as their head types were categorized. the sizing system, which had frequencies more than $4\%$ was classified 6 cases, 7 cases and 9 cases, respectively, by head 3 types. 3 types of size system, which were 56-28-38, 56-30-38 and 57-28-38(Eds note: which of the measurements are head girth, surface length 1 and surface length 2), which were included in 3 clusters. Although head girths were as the same, head surface length was different in size. On the contrary, head surface length was same, head girth was different. The result will contribute to fitness of head wear fitness of consumer, and the amount of production.

• 한국항공우주학회지
• /
• 제38권4호
• /
• pp.309-314
• /
• 2010

기본설계 단계에서 회전익 항공기의 가격을 보다 정확하게 예측하기 위해서 Harris & Scully에 의해 제시된 가격 예측 식을 최신의 추세식으로 수정하였다. 이를 위해 1997년 이후의 총 74개에 대한 회전익기 가격 및 제원 정보를 이용하여 가격 예측 식을 업데이트하였다. 업데이트 된 가격 예측식을 Tishchenko의 기본설계 기법과 통합하여 기본설계 단계에서 가격을 고려하도록 구성하였다. 본 기본설계 및 가격예측 프로그램을 현재 운용되고 있는 미국 Sikorsky사의 S-76C+를 비롯한 여러 기종의 헬리콥터에 적용하여 가격과 제원 결과를 도출하고 검증하여 본 연구의 유효성을 확인하였다.

• 한국항공운항학회지
• /
• 제18권3호
• /
• pp.1-8
• /
• 2010

A design study has been performed to obtain configuration and weight of a compound gyroplane. A study of research trends and characteristics was performed to develop the compound gyroplane sizing program. Based on these results, the sizing program has been developed and its suitability has been validated using existing compound gyroplane data. The subject air vehicles was a Challis Heliplane UAV, Carter Coptet, FB-1 Gyrodyne, and Jet Gyrodyne. As results, the program was suitable to size a compound gyroplane at conceptual design phase, because the greatest error rate was less than 10% and the conceptual design allowance error rate is less than 15%.

• 한국항공우주학회지
• /
• 제33권2호
• /
• pp.22-31
• /
• 2005

본 연구에서는 회전익 항공기의 수직 이/착륙 성능과 고정익 항공기의 고속/고효율 순항 비행 성능을 모두 가지는 Canard Rotor/Wing 항공기 최적 형상설계를 수행하였다. CRW 항공기의 특징인 로터/날개 가변 방식과 로터 회전 시 팁 제트를 통하여 회전력을 얻는 점 때문에 기존의 회전익 또는 고정익 사이징 프로그램만으로는 바로 적용이 어렵고 Reaction Driven 로터에 대한 해석 모듈의 추가와 회전익/고정익 비행 모드 해석이 혼합되어야 한다. 따라서 기존의 사이징 프로그램을 바탕으로 로터 성능, 덕트 유동, 엔진 유동 해석 코드를 연결하여 Reaction Driven 로터 성능 해석이 가능하게 하였으며, 비행체 외형상 특징과 임무별 비행특징이 반영되도록 사이징 프로그램을 개발하였다. 1500 lbs급 소형 무인기에 대하여 비행체 사이징을 수행하고 성능에 크게 영향을 미치는 설계변수를 파악하여 최적화 문제를 구성하였고 전역적 최적화 기법을 이용하여 최소 중량을 가지는 CRW 항공기의 최적형상을 도출하였다.

• 시스템엔지니어링학술지
• /
• 제9권2호
• /
• pp.83-90
• /
• 2013

Integrated aircraft synthesis process for rapid analysis and design is described in this paper. Data flow between different analysis fields is described in details. All the data are divided into several groups according to importance and source of the data. Analysis of design requirements and certification regulations is carried out to determine baseline configuration of an aircraft. Overall design process can be divided into initial sizing, conceptual and preliminary design phases. Basic data for conceptual design are obtained from initial sizing, CAD and geometry analysis. Basic data are required input for weight, aerodynamics and propulsion analyses. Results of this analysis are used for stability and control, performance, mission, and load analysis. Feasibility of design is verified based on analysis results of each discipline. Design optimization that involves integrated process for aircraft analysis is performed to determine optimum configuration of an aircraft on a conceptual design stage. The process presented in this paper was verified to be used for light aircraft design.

• 한국자동차공학회논문집
• /
• 제19권6호
• /
• pp.113-118
• /
• 2011

Fuel Cell Hybrid Vehicle (FCHV) is one of the most promising candidates for the next generation of transportation. It has many outstanding advantages such as higher energy efficiency and much lower emissions than internal combustion engine vehicles. It also has the ability of recovering braking energy. In order to design an FCHV drive train, we need to determine the size of the electric motor, the Fuel Cell System (FCS), and the battery. In this paper, the methodology for the sizing of these components is introduced based on the driveability constraints of the FCHV. A power management strategy is also presented because the battery energy capacity depends on it. The warm-up time of the FCS is also considered in the power management strategy and the simulation result is compared to that without considering the warm-up time.

• 대한인간공학회지
• /
• 제30권5호
• /
• pp.683-688
• /
• 2011

Objective: The aim of this study is to develop a distributed representative human model(DRHM) generation and analysis system. Background: DRHMs are used for a product with multiple-size categories such as clothing and shoes. It is not easy for a product designer to explore an optimal sizing system by applying various distributed methods because of their complexity and time demand. Method: Studies related to DRHM generation were reviewed and the RHM generation interfaces of three digital human model simulation systems(Jack$^{(R)}$, RAMSIS$^{(R)}$, and CATIA Human$^{(R)}$) were reviewed. Results: DRHM generation steps are implemented by providing sophisticated interfaces which offer various statistical techniques and visualization methods with ease. Conclusion: The DRHM system can analyze the multivariate accommodation percentage of a sizing system, provide body sizes of generated DRHMs, and visualize generated grids and DRHMs. Application: The DRHM generation and analysis system can be of great use to determine an optimal sizing system for a multiple-size product by comparing various sizing system candidates.