• 한국광학회지
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• 제14권3호
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• pp.236-243
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• 2003

본 논문에서는 구면수차와 Stiles-Crowford 효과를 고려하여 인간의 눈을 모델링한 정밀모형안과 등가인 렌즈모듈 모형안의 설계에 관하여 논의하였고, 렌즈모듈 모형안을 적용한 Head Mounted Display(HMD)용 광학계를 설계 및 평가하였다. HMD용 광학계에서 요구되는 소형화, 고성능 및 고해상도 등의 필수조건들을 만족시키기 위해 회절광학소자와 비구면을 이용하여 색수차와 단색수차를 보정하였다. SVGA급 480,000화소를 갖는 0.47 인치 micro-display, 플라스틱 hybrid 렌즈, 그리고 렌즈모듈 모형안으로 HMD용 광학계를 구성하였다. 설계된 광학계의 초점거리는 31.25 mm, FOV는 24H$\times$18V$\times$30D degrees, 그리고 전장길이는 59.1 mm이다. 결과적으로, 사용자가 편안함을 느낄 수 있는 HMD에 유용한 광학계를 얻었다.

• 한국분말재료학회지
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• 제22권1호
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• pp.27-31
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• 2015

Flat panel display devices are mainly used as information display devices in the 21st century. The worldwide waste flat panel displays are expected at 2-3 million units but most of them are land-filled for want of a proper recycling technology More specifically, rare earth metals of La and Eu are used as fluorescent materials of Cold Cathode Flourscent Lamp(CCFL)s in the waste flat panel displays and they are critically vulnerable and irreplaceable strategic mineral resources. At present, most of the waste CCFLs are disposed of by land-filling and incineration and proper recovery of 80-plus tons per annum of the rare earth fluorescent materials will significantly contribute to steady supply of them. A dearth of Korean domestic research results on recovery and recycling of rare earth elements in the CCFLs prompts to initiate this status report on overseas research trends and noteworthy research results in related fields.

• Current Photovoltaic Research
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• 제3권2호
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• pp.50-53
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• 2015

Indium (In) is widely used for transparent electrodes of photovoltaics as a form of indium tin oxide (ITO) due to its superior characteristics of environmental stability, relatively low electrical resistivity and high transparency to visible light. However, In has been worn off in proportion to growth the In related market, and it leads to raise of price. Although In is obtained from ITO target scarps, much harmful elements are used for the recycling process. To decrease of harmful elements, ITO swarf particles obtained from target scraps was characterized whether it is feasible to transparent conductive oxide (TCO). The ITO swarf was crushed with milling process, and it was mixed with new ITO nanoparticles. The mixed particles were well dispersed into ink solvent to make-up an ink, and it was well coated onto glass substrate. After heat-treatment at $400^{\circ}C$ under $N_2$ rich environments, optical transmittance at 550 nm and sheet resistance of the ITO ink coated layer was 71.6% and $524.67{\Omega}/{\square}$, respectively. Therefore, it was concluded that the ITO swarf was feasible to TCO of touch screen panel.

• 한국문헌정보학회지
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• 제29권
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• pp.141-172
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• 1995

The main objective of this study is to analyse the information flows and representations which is shown at the displays of the user-OPACs interfaces in the 5 academic library automation systems. The findings made in the study are summarized as follows: 1) The interactive styles of that displays are based on the menu selection style. 2) The structures of information flow on that displays are the compound structure which is basically made of the network, the binary, and the pop-up structures. 3) The elements of the displays are consisted with the fields concerning the database name, the current working area, the indicator, the menu, the exit, the prompt and the system message. 4) The essential entries of the main menus are Book, Periodical. and Thesis. 5) The important languages of the command language styles are Search, Display, Print, Help, and End. 6) The elements of the display structures for the retrieval are the retrieving key, the Boolean operators, and the exit. 7) The major retrieving keys are Title, Author, Subject name, Call Number, and Publisher. 8) The marks of Boolean operators on the retrieval displays is different among the systems each other.

• 대한화학회지
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• 제45권3호
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• pp.236-241
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• 2001

$Y_2O_3$: Eu 형광체는 고효율, 열적 화학적 안정성을 갖고 있어서 평판 표시 소자용 적색 형광체로 널리 사용되고 있다. 고분해능과 고효율을 가지는 평판 표시 소자는 작은 크기의 구형 입자를 가진 형광체를 필요로 한다. 본 연구에서는 착체 중합법을 이용하여 100-300nm크기의 $Y_2O_3$ : Eu 형광체를 제조하였고 1족 혹은 2족 원소를 첨가하여 발광특성에 대한 영향을 검토하였다.

• 제어로봇시스템학회논문지
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• 제12권6호
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• pp.539-546
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• 2006

The Air Quality Sensor(AQS), located near the fresh air inlet, serves to reduce the amount of pollution entering the vehicle cabin through the HVAC(heating, ventilating, and air conditioning) system by sending a signal to close the fresh air inlet door/ventilation flap when the vehicle enters a high pollution area. The sensor module which includes two independent sensing elements for responding to diesel and gasoline exhaust gases, and temperature sensor and humidity sensor was designed for intelligent AQS in automobile. With this sensor module, AVR microcontroller was designed with back propagation neural network to a powerful gas/vapor pattern recognition when the motor vehicles pass a pollution area. Momentum back propagation algorithm was used in this study instead of normal backpropagation to reduce the teaming time of neural network. The signal from neural network was modified to control the inlet of automobile and display the result or alarm the situation in this study. One chip microcontroller, ATmega 128L(ATmega Ltd., USA) was used for the control and display. And our developed system can intelligently reduce the malfunction of AQS from the dampness of air or dense fog with the backpropagation neural network and the input sensor module with four sensing elements such as reducing gas sensing element, oxidizing gas sensing element, temperature sensing element and humidity sensing element.

• 한국정보통신학회논문지
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• 제16권8호
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• pp.1653-1662
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• 2012

최근 차세대 디스플레이로 각광받고 있는 OLED는 다양한 장점들을 가지고 있다. 하지만 발광 소자간의 광효율의 불균형으로 인해 표현하고자 하는 색감이 붕괴된다. 본 논문에서는 영상처리를 이용하여 적은 자원으로 RGB 채널의 불균형문제를 해결 하고 효율이 약한 채널이 넓은 색상 표현 범위를 가질 수 있도록 하는 Adaptive Color Shifter(ACS)를 제안하였다. 제안하는 ACS를 다양한 영상에 적용하여 시뮬레이션 하고 색상 히스토그램과 CIE-1931 xyz 색 공간을 이용하여 수치적인 분석을 하였다.

• 센서학회지
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• 제27권4호
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• pp.269-274
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• 2018

High-sensitivity signal-to-noise ratio (SNR) microphones are essentially required for a broad range of automatic speech recognition applications. Piezoelectric microphones have several advantages compared to conventional capacitor microphones including high stiffness and high SNR. In this study, we designed a new piezoelectric membrane structure by using the finite elements method (FEM) and an optimization technique to improve the sensitivity of the transducer, which has a high-quality AlN piezoelectric thin film. The simulation demonstrated that the sensitivity critically depends on the inner radius of the top electrode, the outer radius of the membrane, and the thickness of the piezoelectric film in the microphone. The optimized piezoelectric transducer structure showed a much higher sensitivity than that of the conventional piezoelectric transducer structure. This study provides a visible path to realize micro-scale high-sensitivity piezoelectric microphones that have a simple manufacturing process, wide range of frequency and low DC bias voltage.

• 한국전기전자재료학회논문지
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• 제28권9호
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• pp.607-614
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• 2015

To provide the clear images from the direct light on electrical board and display devices, anti glare treatment of display cover glass is needed. In this study, the effects of surface treatment temperature, concentration, and etching solution coating thickness of the gel phase on optical elements control such as gloss, haze of reflected light and transmittance, were investigated. Cover glasses were treated at different coating thickness and additive concentration. The optical properties were examined using spectrophotometer, gloss and haze meter. The surface morphology and roughness were measured by the optical microscope and Ra measuring instrument. The etching rate and surface morphologies were dramatically affected by the concentration of acid additive in the viscous gel because of re-crystallization of components in the etching solution, hydrogel formation and coagulant after coating on glass substrate. In our experimental range, cover glass which is surface-treated with various optical properties as well as the morphology uniformity was obtained; in particular, optical properties could be controlled by etching solution coating thickness of the gel phase and the concentration of additive. The gloss was depended on the surface roughness and it showed the linear relationship between optical transmittance and haze of reflected light, respectively.

• 한국멀티미디어학회논문지
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• 제17권12호
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• pp.1511-1520
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• 2014

After 2011, with the spread of smart devices, large interfaces using the architectural space elements here and there in the cities. Recently the desire for the data has increased, and, following the increase of the range of use by the users, the communication utilizing various forms of interfaces is expected to become more active. In the past, certain range of architecture or parts of the facilities were as the interfaces, but, recently, the development of media technology and the display of various contents forced the utilization of many elements of architectural space in the interface aspects that were not used in the past. Accordingly, the research compare the relationship of the purpose, media environments, interface technology, data form and so on and consider the characteristic of what elements of architectural space are used in order to analyze the characteristic of interfaces used in digital art works. Especially,the research will consider the possibility of commercializing the trends in the interfaces of digital art works in the mediation region of city information services, and propose how to apply such possibility.