http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
이민욱(Min-Uk Lee),김형권(Hyeong-Kwon Kim),신상록(Sang-Rok Shin),김훈(Hoon Kim) 한국조명·전기설비학회 2008 한국조명·전기설비학회 학술대회논문집 Vol.2008 No.5월
전국 주요 노선의 고속도로 터널도로를 대상으로 터널조명설비가 기준에 적합한지 그 성능을 차량을 이용한 고성능 터널조명 측정시스템으로 측정함으로써 터널조명의 적절성 여부와 터널조명 변화를 파악하고, 그 결과를 바탕으로 우리나라 터널조명의 실태를 비교 분석하였다.
데이터베이스 백업 성능 향상을 위한 병렬 인덱스 스캔 기법
이민욱 ( Min-uk Lee ),한재현 ( Jaehyun Han ),손용석 ( Yongseok Son ) 한국정보처리학회 2021 한국정보처리학회 학술대회논문집 Vol.28 No.2
데이터베이스 백업은 데이터베이스 데이터를 보존 및 복구하기 위해 사용되는 필수 기법이다. 이를 위해 데이터베이스 관리 시스템(Database Management System)에서는 백업 기능을 수행하는 응용을 제공한다. 하지만 이러한 백업 응용은 기존 HDD 의 특성을 고려하여 설계 및 구현되어있기 때문에 최근 주로 사용되고 있는 저장장치인 SSD 에서는 SSD 의 성능을 최대한 이끌어 내지 못하고 있다. 예를 들어, 기존 백업 응용에서는 단일 스레드가 백업을 위한 데이터를 순차적으로 접근하고 풀 스캔 방식으로 백업을 수행한다. 따라서 본 연구에서는 SSD 의 병렬적 특성을 활용하여 백업 응용의 성능을 극대화시키는 것을 목표로 한다. 이를 위해 본 논문은 병렬 인덱스 스캔 기법을 제시한다. 제안한 기법은 기존 백업 기법과 달리 멀티 스레드를 활용하여 인덱스 스캔을 수행하고 병렬적으로 데이터에 접근하여 백업을 수행한다. 해당 기법은 기존 기법에 비해 최대 2.5 배 성능을 향상시켰다.
이민욱(Min Uk Lee),유정훈(Jung Hun Yoo),이태희(Tae Hee Lee) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.11
Three methods for design sensitivity such as numerical differentiation, analytical method and semianalytical method have been developed for the last three decades. Although analytical design sensitivity analysis is exact, it is hard to implement for practical design problems. Therefore, numerical method such as finite difference method is widely used to simply obtain the design sensitivity in most cases. The numerical differentiation is sufficiently accurate and reliable for most linear problems. However, it turns out that the numerical differentiation is inefficient and inaccurate because its computational cost depends on the number of design variables and large numerical errors can be included especially in nonlinear design sensitivity analysis. Thus semi-analytical method is more suitable for complicated design problems. Moreover semianalytical method is easy to be performed in design procedure, which can be coupled with an analysis solver such as commercial finite element package. In this paper, implementation procedure for the semi-analytical design sensitivity analysis outside of the commercial finite element package is studied and computational technique is proposed, which evaluates the pseudo-load for design sensitivity analysis easily by using the design variation of corresponding internal nodal forces. Errors in semi-analytical design sensitivity analysis are examined and numerical examples are illustrated to confirm the reduction of numerical error considerably.
유한요소프로그램을 이용한 비탄성 구조문제의 준해석 설계민감도해석
이민욱(Min Uk Lee),유정훈(Jung Hun Yoo),이태희(Tae Hee Lee) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11
Implementation procedure for the design sensitivity analysis (DSA) using finite element program(FEP) can be performed inside or outside of FEP. DSA implemented inside of FEP is required information of internal source code. DSA implemented outside of FEP, however, must be performed without access to source code and has been used for linear problems and few nonlinear problems restrictively. In this paper, the implementation procedure of DSA outside of FEP is proposed, which can be available for not only linear but also nonlinear and inelastic problems. Several examples are illustrated to verify the accuracy and reliability of the proposed method.
이진민(Jin Min Lee),이민욱(Min Uk Lee),조수길(Su Kil Cho),구만회(Man Hoi Koo),김학인(Hak In Gimm),이태희(Tae Hee Lee) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11
An open frame structure is fastened by bolt joints for strength and shock attenuation. Therefore the full finite element model of an open frame structure should be properly modeled including bolt joints for strength analysis of the frames and joint assemblies which are operated under multi-loading conditions such as driving, drop, inertia and torsional loads. Then the joints and frames must satisfy the specified allowable strength constraints. Because the full finite element model has a large number of elements to perform strength analysis, a detailed fine bolt analysis seems to be very expensive. Therefore bolts of the full finite element model are approximately modeled by constraints equations to constrain degree of freedoms between adjacent nodes. However, the constraints equation method can exaggerate stress results at the constrained nodes. Thus a detailed bolt analysis and a theoretical/experiential formula of bolts for a worst bolt joint are performed using reaction force applied both bolt and bolt joint. Finally, the results from the two methods are compared and discussed to verify the safety of the open frame structure.
이진민(Jin Min Lee),이민욱(Min Uk Lee),조수길(Su Kil Cho),구만회(Man Hoi Koo),김학인(Hak In Gimm),이태희(Tae Hee Lee) 대한기계학회 2009 大韓機械學會論文集A Vol.33 No.8
An open frame structure is fastened by bolt joints for strength and shock attenuation. Therefore the full finite element model of an open frame structure should be properly modeled including bolt joints for strength analysis of the frames and joint assemblies which are operated under multi-loading conditions such as driving, drop, inertia and torsional loads. Then the joints and frames must satisfy the specified allowable strength constraints. Because the full finite element model has a large number of elements to perform strength analysis, a detailed fine bolt analysis seems to be very expensive. Therefore bolts of the full finite element model are approximately modeled by coupling method to constrain degree of freedoms between adjacent nodes. However, the coupling method can exaggerate stress results at the constrained nodes. Thus a detailed bolt analysis and a theoretical/experiential formula of bolts for a worst bolt joint are performed using reaction force applied both bolt and bolt joint. Finally, the results from the two methods are compared and discussed to verify the safety of the open frame structure.