비선형(非線型) 구조(構造)의 설계민감도(設計敏感度) 해석법(解析法)

유연선,Ryu, Yeon Sun 대한토목학회 1987 대한토목학회논문집 Vol.7 No.4

Methods of nonlinear structural design sensitivity analysis are developed in parallel with the nonlinear finite element structural analysis methods and numerically evaluated. Direct decomposition and iterative solution methods for the secant stiffness approach and direct use of tangent stiffness in the design sensitivity analysis phase are derived and presented as the methods of nonlinear structural analysis and design sensitivity analysis are closely related. From the considerations of theoretical and numerical behavior, the tangent stiffness approach is shown to be efficient as the intermediate results of structural analysis can be effectively used in the design sensitivity analysis stage. 본(本) 연구(硏究)에서는 비선형(非線型) 구조(構造)의 설계민감도(設計敏感度) 해석법(解釋法)을 비선형(非線型) 유한요소(有限要素) 구조해석법(構造解析法)에 대응(對應)하여 개발(開發)하고 이들을 수치예(數値例)를 통(通)하여 평가(評價)하였다. 비선형(非線型) 구조해석법(構造解析法)과 설계민감도(設計敏感度) 해석법(解析法)은 밀접한 관계(關係)를 가지므로, 시칸트강도(剛度)를 이용(利用)한 직접분해법(直接分解法) 및 반복해법(反復解法)과 탄젠트강도(剛度)의 직접사용법(直接使用法)을 유도(誘導) 제시(提示)하였다. 이론적(理論的) 고찰(考察) 및 수치예(數値例)로부터, 구조해석(構造解析) 및 설계민감도해석(設計敏感度解釋)의 연반과정(連攀過程)에서 탄젠트강도법(剛度法)의 효율성(?率性)을 확인(確認)하였다.

非線型 構造의 最適設計시스템에 關한 基礎的 硏究

柳演善 釜山水産大學校 1987 釜山水産大學 硏究報告 Vol.27 No.1

Anonlinear structural optimization system is conceptually designed and its features are discussed. Six major component modules of the system are identified on the basis of their operational tasks. The modular sysem is then designed so that data communications between modules take place through a database with the aid of database management program. In the design of the system, availability of nonlinear finite element structural analysis programs and numerical optimization algorithms for the mathematical programming problems is assumed. Based on the present study, a general-purpose nonlinear structural optimization system can be developed with the favorable features of versatility and portability. It is also found that any new analysis codes or optimization algorithms can be easily incorporated or replaced in the system as the total independence of modules is assured.

沿岸施設物의 安定性 및 機能解析에 關한 硏究

柳演善,柳靑魯 釜山水産大學校 1987 釜山水産大學 硏究報告 Vol.27 No.1

The purposes of this paper are to identify the existing state-of-the-art and to present the synthetic review and critical discussions on the analyses of coastal structures. Various methods or procedures which are currently used for the analyses of stability and functions are reviewed to define the applicability of empirical/experimental formulas and theoretical results. From the study, a useful monograph on the stability and function analyses of coastal structures is made.

메탄올탈수소효소 저해시 메탄산화에 의한 메탄올 전환생성 특성

유연선(Yeon Sun Yoo),한지선(Ji Sun Han),안창민(Chang Min Ahn),민동희(Dong Hee Min),모우종(Woo Jong Mo),윤순욱(Soon Uk Yoon),이종규(Jong Gyu Lee),이종연(Jong Yeon Lee),김창균(Chang Gyun Kim) 大韓環境工學會 2011 대한환경공학회지 Vol.33 No.9

본 연구에서는 메탄의 생물학적 메탄올 전환에 관한 연구를 수행하였다. 바이오가스 중의 메탄은 메탄산화균의 methane monooxygenase (MMO)의 생물학적 촉매반응에 의해 산화되었으며, 인산염, NaCl, NH₄Cl, EDTA와 같은 methanol dehydrogenase(MDH)의 활성 저해제를 이용하여 MDH의 활성도를 저해함으로써 메탄올의 전환이 이루어졌다. 메탄산화균은 35℃, pH 7, 인공 바이오가스(CH₄ 50%, CO₂ 50%) / Air의 부피비가 0.4인 조건에서 메탄 산화 정도가 0.56 mmol로 최대로 나타났다. 인산염40 mM, NaCl 50 mM, NH₄Cl 40 mM, EDTA 150 μm 이하일 때 저해제의 종류에 상관없이 메탄 산화율은 80% 이상을 달성하였다. 한편, 인산염 40 mM, NaCl 100 mM, NH₄Cl 40 mM, EDTA 50 μm 주입 시 각각 1.30, 0.67, 0.74, 1.30 mmol의 메탄이 산화되는 동시에 각각 0.71, 0.60, 0.66, 0.66 mmol의 메탄올이 최대로 생성되었다. 이때의 메탄올 전환율은 각각 54.7, 89.9, 89.6 및 47.8%였으며 최대 메탄올 생성 속도는 7.4 μmol/mg·h였다. 이로부터 대상 저해제로 MDH 활성도를 일반적으로 35% 저해 시에메탄올 생산량이 최대인 89.9%까지 나타남을 알 수 있었다. This study was conducted to biologically convert methane into methanol. Methane contained in biogas was bio-catalytically oxidized by methane monooxygenase (MMO) of methanotrophs, while methanol conversion was observed by inhibiting methanol dehydrogenase (MDH) using MDH activity inhibitors such as phosphate, NaCl, NH₄Cl, and EDTA. The degree of methane oxidation by methanotrophs was the most highly accomplished as 0.56 mmol for the condition at 35℃ and pH 7 under 0.4 (v/v%) of biogas (CH₄ 50%, CO₂ 50%) / Air ratio. By the inhibition of 40 mM of phosphate, 50 mM of NaCl, 40 mM of NH₄Cl and 150 μm of EDTA, methane oxidation rate could achieve more than 80% regardless of type of inhibitors. In the meantime, addition of 40 mM of phosphate, 100 mM of NaCl, 40 mM of NH₄Cl and 50 μm of EDTA each led to generating the highest amount of methanol, i.e, 0.71, 0.60, 0.66, and 0.66 mmol when 1.3, 0.67, 0.74, and 1.3 mmol of methane was each concurrently consumed. At that time, methanol conversion rate was 54.7, 89.9, 89.6, and 47.8% respectively, and maximum methanol production rate was 7.4 μmol/mg·h. From this, it was decided that the methanol production could be maximized as 89.9% when MDH activity was specifically inhibited into the typical level of 35% for the inhibitor of concern.

가스사출성형을 이용한 휴대용 화장품 보관함 개발

李琥相,柳淵善 충주대 산업과학기술연구소 2001 産業科學論文集 Vol.9 No.-

The gas-assisted injection molding process is often perceived to be unpredictable, because of the extreme sensitivity of the gas. Since a slight change in design or process parameters can significantly change the resulting gas penetration, few designers and molders have the level of experience with the new gas-assisted injection molding process required for the development of new parts. This paper is concerned with the unified molding for a thick cosmetic chest by using gas-assisted injection molding. CAE analysis was carted out to design the part and the gas channel without inducing sink marks. And based on the part weight measurement, the processing parameters to control gas penetration percentage were chosen through the method of design of experiments. A thick cosmetic chest was successfully produced using the gas assist technology. The sink mark issue associated with the conventional injection molded parts was resolved. Weight savings and cycle-time reduction were also achieved.

사물인터넷 기술을 이용한 가스상 물질 측정용 스마트센서 개발과 향후과제

김욱,김영교,유연선,정기효,최원준,이완형,강성규,함승헌 한국산업보건학회 2022 한국산업보건학회지 Vol.32 No.1

Objectives: To develop the smart sensor to protect worker’s health from chemical exposure by adopting ICT (Information and Communications Technology) technologies. Methods: To develope real-time chemical exposure monitoring system, IoT (Internet of Things) sensor technology and regulations were reviewed. We developed and produced smart sensor. A smart sensor is a system consisting of a sensor unit, a communication unit, and a platform. To verify the performance of smart sensors, each sensor has been certified by the Korea Laboratory Accreditation Scheme (KOLAS). Results: Chemicals (TVOC; Total Volatile Organic Compounds, Cl2: Chlorine, HF: Hydrogen fluoride and HCN: Hydrogen cyanide) were selected according to a priority logic (KOSHA Alert, acute poisoning statistics, literature review). Notifications were set according to OEL (occupational exposure limit). Sensors were selected based on OEL and the capabilities of the sensors. Communication is designed to use LTE (Long Term Evolution) and Wi-Fi at the same time for convenience. Electronic platform were applied to build this monitoring system. Conclusions: Real-time monitoring system for OEL of hazardous chemicals in workplace was developed. Smart sensor can detect chemicals to complement monitoring of traditional workplace environmental monitoring such as short term and peak exposure. Further research is needed to expand the scope of application, improve reliability, and systematically application.

상악동 및 병변 분할을 위한 2D, 2.5D 및 3D 네트워크에 대한 고찰

김다엘(Dael Kim),유연선(Yeon-Sun Yoo),이원진(Won-Jin Yi) 대한전기학회 2023 정보 및 제어 심포지엄 논문집 Vol.2023 No.10

딥 러닝을 이용한 CBCT 영상에서 상악동과 병변 자동 분할 방법

김다엘(Da-El Kim),유연선(Yeon-Sun Yoo),양수(Su Yang),김진(Jin Kim),강세룡(Se-Ryong Kang),천소영(So-Young Chun),유지용(Ji-Yong Yoo),최민혁(Min-Hyuck Choi),노시연(Siyeon Noh),김세훈(Sehum Kim),이원진(Won-Jin Yi) 대한전자공학회 2022 대한전자공학회 학술대회 Vol.2022 No.4

마이크로프로세서를 이용한 자동배급장치에 관한 연구

오형석(Oh Hyung-Suk),유연선(Yoo Yeon-Sun),박현주(Park Hyun-Ju) 한국통신학회 2014 한국통신학회 학술대회논문집 Vol.2014 No.1

육계의 산육성에 관한 연구

김병태(B . T . Kim),유용걸(Y . G . Yu),유연선(Y . S . Yu),박형기(H . K . Park) 한국축산학회 1987 한국축산학회지 Vol.29 No.12

This experiment was carried out to investigate the capability of meat production in two strains of broilers, Arbor Acres and Shaver Starbro. Eight chicks of each sex were slaughtered at 5, 6 and 7 weeks of age, respectively, in both strains, The results obtained were as follows: 1. Overall mean of the carcass weight was greater for the Arbor Acres than for the Shaver Starbro. 2. The lean meat weight of the Arbor Acres was heavier than that of the other strain. The lean meat ratio of the Arbor Acres was heavier at 6 weeks of age than either 5 weeks or 7 weeks. 3. The ratio of the average edible portion of the Arbor Acres to that of Shaver Starbro was positively deviated from unity. 4. Fat deposit in the carcass of male chicks, was gradually decreased with age increment, while the trend was opposit in female chicks. 5. Ratio of bone to carcass weight was highest at 5 weeks of age in both sexes. However, the ratio of muscle to carcass weight was high at 6 weeks and that of carcass fat at 7 weeks of age. 6. Carcass of male chicks had higher protein and moisture than that of female. The moisture was gradually decreased as the birds were getting older.