• 한국전산유체공학회:학술대회논문집
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• 2004.10a
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• pp.165-171
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• 2004

Smart UAV, which adopting tiltrotor aircraft concept, requires long endurance and high speed capability simultaneously These two contradictable flight performances are hard to meet with single wing concept and inevitably require the operation of flap system which should reveal optimal performance for each flight mode. In order to design SUAV flaperon satisfying the performance requirement, various configurations are generated and their aerodynamic performances are analyzed using numerical flow computations around flaps. Considering aerodynamic performance and manufacturing simplicity, a final flap configuration is selected.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1296-1299
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• 2000

A single stage AC/DC converter based on a full bridge topology suitable for high frequency soft switching converter applications is proposed. The proposed converter has high power factor, zero voltage switching, low noise and high efficiency. A pulse width modulation control is employed to reduce the switching and rectification losses respectively. This proposal converter has simple structure and low cost, The modelling and detailed analysis are performed to derive the design equations, a prototype converter has been designed and experimented. The new converter is attractive for high-voltage, high-power applications where IGBT's are predominantly used as the power switches. The principle of operation, features, and design are verified on a 1.5kW, 30kHz, IGBT based experimental circuit.

• Special Issue of the Society of Naval Architects of Korea
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• 2008.09a
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• pp.106-111
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• 2008

A hull form is 181K DWT Bulk Carrier, of which new design and hull form have been developed using CFD tools and model tests. The basic concept design of hull form has been carried out with considering the factors, which are a lot of influence of the wave and viscosity resistance. The considered factors of particular are LCB, DLWL shape, tern and stem profile, Cp-curve shape, etc. Numerical calculations are carried out in the initial design stage and experimental model tests are also carried out in towing tank of MOERI. The variation of the significantly effective characteristics is carried out to achieve optimized hull form. The results from numerical calculations and model test as well as the design procedures to obtain an optimized hull form resent in this paper.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.172-177
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• 2004

This paper presents the results of the structural analysis and optimal design of frames of the UUV(Unmanned Underwater vehicle) to be operated at 6000m depth in the ocean. The structure of the UUV system can be classified into two structure, Launcher ana ROV. Frame of the launcher will be made by Galvanized Steel which has high strength and corrosion-resistant but this material has high specific gravity for tile object to be weight in the water Similarly, ROV will be made by AI6061-T6, and frame of the ROV will be fix many instruments and syntactic buoyancy materials. Before fabrication of tile frame, we performed sensitivity analysis - change in weight due to $\pm1\%$ change in design variables, for easy choice by change of dimension of the frame.

• Bulletin of the Korean Space Science Society
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• 2011.04a
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• pp.30.4-31
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• 2011

The Korea Astronomy and Space Science Institute (KASI) and the Department of Astronomy at the University of Texas at Austin (UT) are developing a near infrared wide-band high resolution spectrograph, IGRINS (Immersion Grating Infrared Spectrograph). The white-pupil design of the instrument optics uses 7 cryogenic mirrors including 3 aspherical off-axis collimators and 4 flat fold mirrors. Two of the 3 collimators are H- and K-band pupil transfer mirrors and they are designed as compensators for the system alignment in each channel. Therefore, their mount design will be one of the most sensitive parts in the IGRINS optomechanical system. The design work will include the computer-aided 3D modeling and finite element analysis (FEA) to optimize the structural stability of the mount models. The mount body will also include a tip-tilt and translation adjustment mechanism to be used as the alignment compensators.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.1
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• pp.137-146
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• 2020

In this study, various application schemes of seismic isolation system which can be applied to Hanok have been studied by analyzing its structural characteristics under seismic load. Structural stability of Hanok is more required against seismic load as Hanok becomes long-spanned and multi-storied. To meet this goal, it becomes necessary to study more advanced technology such as seismic isolation design as well as seismic control design and seismic resistant design suitable to Hanok. Seismic isolation systems have been successfully applied to RC and steel structures to improve structural performance during earthquakes. Based on these previous study, we proposed four application schemes of seismic isolation design suitable for Hanok and analyzed their structural characteristics and applicability to Hanok in conceptual level based on its structural characteristics. The proposed four schemes are base isolation method, ground isolation method, roof isolation method and intermediate-story isolation method. The applicability of the proposed method was evaluated by performing boundary nonlinear dynamic analysis to the typical Hanok for the two types of isolation method, that is, ground isolation method and roof isolation method, and the results showed that the proposed methods produced good performance enough to be applied to Hanok.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.4
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• pp.375-382
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• 2011

Nowadays computer graphic softwares have opened a lot of potential by providing parametric modeling and generative algorithms which are useful not only to describe various geometrical shapes but also to implement a designer's intent in terms of modules systematically. This study has proposed a way of developing a module for generating preliminary structural configuration using such potential computer graphics. Especially parametric modeling and generative algorithm are utilized to define various design alternatives, and moreover use of dynamic graphics enables designers to generate a structural form on one side and a force flow diagram correspondingly provided on the other. This ultimately leads to rational preliminary design of a structural form considering its force flow.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.725-730
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• 2004

This paper has regarded mechanism design of cane-like passive type walking aid for the elderly using 3-RPS parallel manipulator. First, gait patterns of the elderly have been experimented. By means of motion capturing and image processing, we decided loaded forces and places of the cane when the elderly walked with a cane. Using these results we have developed a passive type walking aid. Second, the walking pattern has been simulated using dynamic analysis program, ADAMS and we find out the similarity between the real walking and the simulated walking. Finally after assuring the similarity, with adjusting the new mechanism design to the simulated walking we will decide whether the walking aid is safe and stable when the elderly walks with this cane-like walking aid. This paper will be basis for the development of the mechanism design applying 3-RPS parallel manipulator.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.21-26
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• 2007

유선 인터넷에서 인스턴트 메신저는 간단한 질문/확인, 만남이나 작업 조정, 사회적인 친교 등을 위해 광범위하게 활용되고 있다. 이를 무선으로 확장하기 위하여 MSN, Yahoo, AIM, ICQ, 버디버디, 네이트온 등이 모바일용 메신저를 내놓고 있다. 특히 한국 10대의 경우 SMS를 실시간 대화에 가깝게 (짧고 빈번하게) 사용하고 있기 때문에 무선 메신저는 큰 호응이 있으리라 예상하였다. 그러나 네이트온 모바일 메신저의 경우, 2002년 출시된 이후 별다른 인기를 끌지 못하고 있다. 이에 저자들은 네이트온 사용자들의 사용행태를 분석하여 문제점을 파악하고, 일반 SMS 사용자들과 네이트온 사용자들의 무선 커뮤니케이션 사용행태를 1주일간의 Diary Study에 기초한 Contextual Inquiry (Intermittent)를 실시하여 사용률이 저조한 이유를 분석한 뒤, 퍼소나를 구성하여 무선 환경에 맞는 완전히 혁신적인 새로운 형태의 무선 메신저 사용자 인터페이스를 설계하였다. 메신저에 반드시 있는 사용자 등록이나 친구 추가 기능을 없애고 휴대전화 번호 기반으로 동작하며, 상태 정보(Presence)를 없애면서 상대방 상태에 따라 IM 혹은 SMS로 적절히 변환되어 전달되는 것이 주요 특징이다. 이를 사용자들을 통해 다시 검증해 본 결과 사용자들이 무척 쉽게 받아들이는 것을 발견하였다.

• Proceedings of the KSR Conference
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• 2006.11a
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• pp.171-180
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• 2006

The EMS system requires a very delicate suspension control to maintain constant air-gap between the magnet and the guide-way rail. To maintain a constant air-gap with attraction force, the EMS system dynamics is changed according to uncertainties and disturbances, and it also requires reliability against component failures. Since uncertainties and component failures are frequently caused in EMS system, it is very important to develop the robust and reliable control system. In this paper, we consider the design problem for robust and reliable controller in the presence of uncertainties and component failures.