• Proceedings of the Korean Information Science Society Conference
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• 2007.10b
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• pp.404-407
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• 2007

플래시 메모리는 비휘발성, 저 전력, 빠른 입출력, 충격에 강함 등과 같은 많은 장점을 가지고 있으며 모바일 기기에서의 저장 매체로 사용이 증가 되고 있다. 뿐만 아니라 기존 하드디스크를 대체하는 용도로도 사용하고 있다. 하지만 제자리 덮어쓰기가 불가능하고 지움 연산의 단위가 크다는 제약 및 블록의 지움 횟수 제한이 있다. 이러한 제약을 극복하기 위해 YAFFS와 같은 로그 구조 기반의 플래시 파일 시스템들이 개발 되었다. YAFFS와 같은 로그 구조 기반의 플래시 파일 시스템은 마운팅시에 시스템에 필요한 데이터들을 얻기 위해 전체 플래시 메모리를 읽어야 한다. 이러한 파일 시스템의 마운팅 과정은 전체 시스템의 부팅 시간을 지연시킨다. 본 논문에서는 위와 같은 문제점 해결을 위하여 빠른 부팅을 제공 할 수 있는 NAND 플래시 파일 시스템 구조 및 제안한 구조에서의 시스템 일관성 유지를 위한 빠른 복구 방법들을 제안한다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.4
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• pp.14-22
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• 2022

To reduce the weight of the car and ensure the safety of the driver while driving, the existing 440 MPa-class mounting bracket was treated at 590MPa to improve collision safety and secure the weight of the vehicle body. The following conclusions were drawn from the tensile test, forming analysis, and springback prediction. In the formability and springback analyses using FLD, it could be confirmed that bending was an essential process because the formability and flatness were much better when bending was added than when bending was not applied. Based on the research results, it was deduced that the mold design was necessary so that the molding was carried out at a strain rate of 20% or less for stable molding.

• The Journal of the Acoustical Society of Korea
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• v.28 no.8
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• pp.781-789
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• 2009

The absorption coefficients of the materials used in a 1:50 scale model multipurpose hall were measured based on ISO 354 and related laws. The shape and materials for the scale model were evaluated based on reflective surfaces, variable acoustic elements and sound-absorbing quality (125Hz-1kHz average) of seats. The measured average absorption coefficients of audience seats, audience and orchestra were 0.64, 0.74 and 0,45, respectively, which were simulated with the combination of wood, absorption materials and foam board. Various mounting methods for absorption curtain and banner were considered according to the installation methods. The average absorption coefficient was measured as 0.42, 0.47 and 0.45 in the conditions of Type A mounting, E mounting with 0.9 m backing air cavity, and Type G mounting which is suspended at the ceiling, respectively. It was confirmed that the absorption coefficient was increased at low frequency by backing air gap. The finishing material of stage house was an absorption material covered with thin fabric, which aimed average absorption coefficient of 0.68 by using fiber glass board. Each part of the real materials was compared with those of 1:50 scale model and it was found that the absorption characteristics of both cases were similar.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1301-1302
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• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.717-718
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• 2014

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.512-513
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• 2011

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.4
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• pp.525-531
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• 2012

This study aims at the structural analysis of vibration and fatigue according to the configuration of engine mount. Maximum equivalent stress or deformation is shown at bracket or case respectively. As harmonic vibration analysis, the maximum displacement amplitude is happened at 4,000Hz. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' or 'Saw tooth' becomes most stable. In case of 'Sample history' or 'Saw tooth' with the average stress of 4,200MPa or 0MPa and the amplitude stress of -3,000MPa or 7MPa, the possibility of maximum damage becomes 70%. This stress state can be shown with 7 times more than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The structural result of this study can be effectively utilized with the design on engine mount by investigating prevention and durability against its damage.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.178-178
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• 1993

생리활성 펩타이드류의 경점막 수송을 검토하기 위하여 토끼의 비강, 직장, 질 또는 눈 점막 구출액에서의 메치오닌엔케팔린 (Met-Enk) 및 그 합성 유사체인 [D-알라$^2$]-메치오닌엔케팔린아미드 (YAGFM)의 효소적 분해를 억제하고자 수종 효소억제제를 검토하였다. 방법: 토끼의 질, 직장 및 비강 점막을 차례로 적출하여 신속히 Valia-Chien투과셀에 마운팅하고, 눈의 각막은 절취하여 따로 각막 투과셀에 마운팅한 다음 등장 인산염 완충액 3.5ml씩으로 8시간씩 3회 추출하여 점막측 및 장막측 추출액을 제조하였다. 추출 완료 직후 이들 추출액에 Met-Enk 또는 YAGFM 50$\mu\textrm{g}$/ml의 농도로 첨가하고 여러 효소억제제를 단독 또는 혼합하여 첨가한 조건에서 37$^{\circ}C$에서 60 rpm으로 24시간 동안 흔들면서 경시적으로 시료를 취하여 잔존 펩타이드의 양을 HPLC법으로 정량하여 속도론적으로 비교 검토하였다. 이 연구에 사용한 효소억제제로는 아미노펩티다제의 억제제인 amastatin (AM), bestatin (BS). 엔케팔리나제 A의 억제제로 알려진 thiophan (TP), 엔케팔리나제 B의 억제작용이 있는 것으로 밝혀진 thimerosal (TM), metalloenzyme의 억제제인 에데트산나트륨 (EDTA) 등을 검토하였고 또 $\beta$-시클로덱스트린 유도체인 디메칠-$\beta$-시클로덱스트린과 2-히드록시프로필-$\beta$-시클로덱스트린이 펩타이드의 분해억제효과도 함께 검토하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.6
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• pp.353-358
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• 2018

In this study, it is describe to an optimization analysis process for the weight reduction of the voltage converter in the electric vehicle charging systems. The optimization design is a technique that finds the optimal material distribution under a given material quantity constraint by combining the design sensitivity with the material properties and the mathematical optimization. Among the topology optimization, a lightweight design is performed by a solid isotropic material with penalization with simple formula and well-convergence. The lightweight design consists of three steps. As a first step, a finite element model for the basic design of the on-board voltage converter was constructed and static analysis was performed on the load. In the second step, the optimum shape is obtained for the lightweight by performing the topology optimization using the solid isotropic material with penalization applying the stiffness coefficient of the isotropic material to the static analysis result. As a final step, impact analysis was performed by applying a half-sinusoidal pulse shape impact load which satisfies the impact test standard of the vehicle-mounted part with respect to the optimum shape. In the topology optimization, the design domain was defined as the mounting bracket area, and the design technology was finally achieved by optimizing the mounting bracket to achieve a weight reduction of 20% over the basic design.

• Journal of KSNVE
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• v.6 no.3
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• pp.274-285
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• 1996

본 글에서는 대형차량의 엔진 마운트 과정과 마운트 설계시 필요한 사항들에 대하여 간략히 정리해 보았다. 먼저 2장에서는 비교적 형상이 간단한 대형 차량의 마운트 강성을 정확히 설계하는 과정을 제시하였는데, 이 방법에 따라 아운트 재질에 대한 탄성계수를 데이터 베이스화 함으로써 다양한 경우에 원하는 특성을 갖는 마운트를 쉽게 설계할 수 있음을 보였다. 3장에서는 마운팅 설계를 위한 기초 데이터 -관성특성 및 가진력 등에 대하여 기술하였으며, 4장에서는 마운트 최적 설계과정을 정리하였다. 여기서 마운트의 강성을 선정하는 방법과 프레임의 유연성이 엔진 동특성에 미치는 영향을 고찰 최적화하는 과정을 기술하였다. 또한 시혐적 검토에 의한 평가방법을 5장에서 서술함으로 일반적인 엔진 마운트에서의 최적 설계에 대한 내용을 서술하였다.