• 비파괴검사학회지
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• 제29권6호
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• pp.591-602
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• 2009

The Compton backscatter technique has been applied to lap-joint in aircraft structure in order to determine mass loss due to exfoliative corrosion of the aluminum alloy sheet skin. The mass loss of each layer has been estimated from Compton backscatter A-scan including the aluminum sheet, the corrosion layer, and the sealant. A Compton backscattering imaging system has been also developed to obtain a cross-sectional profile of corroded lap-splices of aging aircraft using a specially designed slit-type camera. The camera is to focus on a small scattering volume inside the material from which the backscattered photons are collected by a collimated scintillator detector for interpretation of material characteristics. The cross section of the layered structure is scanned by moving the scattering volume through the thickness direction of the specimen. The theoretical model of the Compton scattering based on Boltzmann transport theory is presented for quantitative characterization of exfoliative corrosion through deconvolution procedure using a nonlinear least-square error minimization method. It produces practical information such as location and width of planar corrosion in layered structures of aircraft, which generally cannot be detected by conventional NDE techniques such as the ultrasonic method.

• 한국기록관리학회지
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• 제3권2호
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• pp.98-113
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• 2003

사진은 다른 기록물과 비교하여 물리적 특성과 정보를 담고 있는 형식의 차이 때문에 특별한 관리를 필요로 한다. 이에 대학 아카이브즈에서 빈번하게 이용되는 사진자료의 효율적인 이용과 관리를 위한 방안으로서, 먼저 대학 관련 사진이미지를 싣고 있는 대학 간행물에서 사진이미지를 추출하고, 서지정보를 파악하여 워크시트를 작성하고, 이를 토대로 사진자료의 서지데이터베이스를 구축하였다. 다음으로 대학 간행물로부터 추출해낸 사진이미지를 편집하고 이를 서지데이터베이스에 링크시킴으로서 사진의 서지정보 검색과 더불어 이미지를 즉시 확인할 수 있는 데이터베이스 구축과정을 사례를 중심으로 소개하고 몇 가지 문제점과 향후 개선방향에 대하여 살펴본다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.45-45
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• 2008

In recent years, new materials and technology has been developed using single-walled carbon nanotubes (SWCNTs) as an alternative to indium tin oxide (ITO) to fulfil the requirements towards novel technological drive. These technologies offer products having a broad range of conductivity, excellent transparency, neutral color tone, good adhesion, abrasion resistance as well as mechanical robustness. In addition, SWCNTs can be solution processed to replace the sophisticated vacuum techniques at high temperatures. In the present work, transparent conducting films were fabricated from the purified SWCNTs. Dispersion of purified SWCNTs was accomplished in 1,2-dichlorobenzene without using surfactants or polymers following ultrasonic process. We achieved coating of nanotubes film on poly ether suiphone (PES) for an average sheet resistance ~110 ${\Omega}/{\Box}$ of optical transmittance 80% at 550 nm. Conventional spin coating method was followed to fabricate films from the purified and dispersed nanotubes solution. The results will be presented.

• 한국통신학회논문지
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• 제29권5C호
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• pp.716-725
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• 2004

본 논문에서는 VHLS 광학판 기반의 새로운 다시점 3D 디스플레이 시스템을 제시하였다. 즉, VHLS 광학판을 체적 홀로그램의 각 다중화 기록 특성을 이용하여 다시점 영상의 방향벡터를 회절격자 형태로 기록한 일종의 광방향 변조기로 제작한 다음, 제작된 VHLS을 LCD 공간광변조기에 부착되어 패널에 입력되는 다시점의 스테레오 영상을 각 시점에 해당하는 특정방향으로 분리해 줌으로써 다시점 3D 디스플레이 시스템을 실현하였다. 또한, 본 논문에서는 VHLS 광학판의 원리와 특성을 분석한 다음 상용 포토폴리머를 이용하여 최적화된 4시점의 VHLS 광학판을 설계 제작하고 이를 이용하여 4시점의 스테레오스코픽 3D 디스플레이 시스템을 구현하였다. 그리고 적응적 변위 추정 알고리즘으로 합성된 4시점의 테스트 영상을 이용한 광학실험을 통해 VHLS 기반의 다시점 3D 디스플레이 시스템의 구현 가능성을 제시하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1575-1577
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• 2009

We have investigated the characteristics of transparent indium zinc oxide(IZO)/Ag/IZO multilayer electrode grown on polyethylene terephthalate (PET) substrates using a specially designed roll-to-roll sputtering system for use in flexible device are described. By the continuous R2R sputtering of the bottom IZO, Ag, and top IZO layers at room temperature, we were able to fabricate an IZO-Ag-IZO multilayer electrode with a sheet resistance of 6.15 ${\Omega}$/square, optical transmittance of 87.4 %, and figure of merit value of 42.03 10-3 ${\Omega}$-1. In addition, the IZO-Ag-IZO multilayer electrode exhibited superior flexibility to the RTR sputter grown single ITO electrode, due to the existence a ductile Ag layer between the IZO layers. This indicates that the RTR sputtered IZO-Ag-IZO multilayer is a promising flexible electrode that can substitute for the conventional single ITO electrode grown by bath type sputtering for use in low cost flexible device, due to its low resistance, high transparency, superior flexibility and fast preparation by the R2R process.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.330-335
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• 2002

Resistance spot welding is one of the most widely used processes in sheet metal fabrication. Quality assurance of welding has been important to increase the productivity. In this study, weld quality estimation using primary circuit dynamic resistance applied to the in-process real-time systems. For quality estimation, factors relating to quality were extracted from the dynamic resistance, measured in the timer. The relationship between these factors and weld quality was determined through a artificial neural network model. This method has the advantage over the conventional one, such as obtaining the quality information without the use of extra devices.

• Journal of Information Display
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• 제11권2호
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• pp.52-56
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• 2010

High-efficiency organic light-emitting diodes (OLEDs) based on multilayer transparent electrodes (MTEs) are reported. The dielectric/metal/dielectric (DMD) multilayer electrode based on a thin silver layer achieved high sheet conductance as small as $6{\Omega}/sp$ and a tuning capability in the optical and electrical properties by engineering the inner and outer dielectric layers. In the conventional normal bottom-emitting structure, a DMD-based OLED can be fabricated with 90% higher forward luminous efficiency and 30% higher external quantum efficiency (EQE) compared to ITO-based devices. Special attention was paid to the optimization method of such MTE structure considering both the injection and optical structures.

• 전자공학회논문지SC
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• 제42권1호
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• pp.1-11
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• 2005

본 연구에서는 다양한 재료의 시트(Sheet)를 각각 절단하여 적층하는 방법으로 기존 적층조형법과는 다른 쾌속 임의형상제작 시스템인 CAFL/sup VM/(Computer Aided Fabrication of Lamination for Various Material)을 제안한다. 이러한 조형 방법은 가공 속도를 빠르게 하며 복잡한 후처리 과정을윽 대폭 줄일 수 있고, 여러 가지 재료가 사용 가능한 장점을 지니고 있다. 이러한 목적으로 개발된 2자유도의 X-Y테이블 형태의 CAFL/sup VM/은 레이저빔으로 시트(Sheet)를 절단, 적층하여 조형물을 완성하는 새로운 고속적층 시스템으로 가능성을 검증하였다. 하지만 2자유도 시스템은 X-Y 평면을 이동하는 작업공간에 수직으로 레이저 가공이 이루어지는 방법으로, 조형된 사물의 표면에 계단 형상이 나타나는 표면정밀도상의 문제점을 드러낸다. 이러한 문제점을 해결하고자 2자유도에 3자유도를 추가한 5자유도 시스템을 제안하여 레이저의 경사절단이 가능하게 함으로서 조형된 사물의 표면 정밀도를 높이고, 일정한 패턴의 모양을 갖는 조형물 가공의 경우 여러 시트(Sheet)가 적층되는 부분을 한번에 가공할 수 있도록 하여 보다 빠르고 정밀한 5자유도 매니퓰레이터 CAFL/sup VM/ 시스템을 설계한다. 즉, 정속경로제어와 경사각절단제어를 구현하고 그 외에 수반된 자동화 CAFL/sup VM/ 시스템을 구현하는 것이 본 논문의 목적이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.416-417
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• 2007

We prepared flexible transparent conducting electrodes by spray coating of single-walled carbon nanotube (SWNT) networks on PET substrate and have demonstrated their use as transparent anodes for flexible organic light emitting diodes (OLEDs). The flexible CNT electrode produced by spray coating method shows relatively low sheet resistance ($150{\sim}220{\Omega}/sq.$) and high transmittance of ~60% even though it was prepared at room temperature. In addition, CNT electrode/PET sample exhibits little resistance change during 2000 bending cycles, demonstrated good mechanical robustness. Using transparent CNT electrode, it is readily possible to achieve performances comparable to commercial ITO-based OLEDs. This indicates that flexible CNT electrode is alternative anode materials for conventional ITO anode in flexible OLEDs.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.521-524
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• 2005

In order to measure ECG in daily life, a new ECG measurement method on bed was developed. The provided method does not require any direct conductive contact between the instrument and bare skin, so that it does not cause the uncomfortable feel of touch and the possible skin trouble which are typical shortcomings of the conventional conductive contact ECG measurement. The provided method utilized an array of high-input-impedance active electrodes fixed on the mattress and an indirect-skin-contact ground made of a large conductive textile sheet and laid on lower area of the mattress. A thin cotton bedcover covered the mattress, the electrodes, and the conductive textile and subjects lay on the mattress over the bedcover. ECG was obtained successfully. However its signal quality is lower and the motion artifact is larger than direct-contact measurement. Careful measurement setup was needed to reduce the motion artifact originated from variation in static electricity. From the ECG obtained by the provided method, R-peak could be discriminated easily and the information about the position and the posture of the subject could be obtained.