• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.416-419
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• 2002

There are being two prominent studying for Digital Radiography. Direct and Indirect method of Digital Radiography are announced for producing high quality digital image. The one is using amorphous selenium as photoconductor and the other is using phosphor layer as a light conversion. But each two systems have strength and weakness such as high voltage and blurring effect. In this study, we investigated the electrical characteristic of $multi-layer\left(CaWO_{4}+a-Se \right)$ as a photoconductor according to the changing arsenic composition ratio. This is a basic research for developing of Hybrid digital radiography which is a new type X-ray detector. The arsenic composition ratio of a-Se compound is classified into 7 different kinds which have 0.1%, 0.3%, 0.5%, 1%, 1.5%, 5%, 10% and were made test sample throught thermo-evaporation. The phosphor layer of $CaWO_4$ was overlapped on a-Se using EFIRON optical adhesives. We measured the dark and photo current about the test sample and compared the electrical characteristic of the net charge and signal-to-noise ratio. Among other things, test sample of compound material of 0.3% arsenic showed good characteristic of $2.45nA/cm^2$ dark current and $357.19pC/cm^2/mR$ net charge at $3V/{\mu}m$.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.106-110
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• 2005

In this paper, LED traffic signal lamp's operating circuit using Flyback converter and PFC IC has been presented. Most power conversion circuits use PFC IC for Power Factor Correction. The design parameter's value of Flyback converter has been proposed and the error amplifier which regulates the output voltage has been designed Besides, the under voltage protection circuit and the over voltage protection circuit for protecting the operating circuit kin unbalance of common electric power source and the temperature compensation circuit for fixed optical output power have been proposed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1351_1352
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• 2009

We deposited $SnO_2$:F thin films by atomospheric pressure chemical vapor deposition(APCVD) on corning glass. $SnO_2$:F films were used as transparent conductive oxide (TCO) electrode for Si thin film solar cells. We have investigated structural, electrical and optical properties of $SnO_2$:F thin films and fabricated thin film Si solar cells by plasma enhanced CVD(PECVD) on $SnO_2$:F thin films The cells were characterized by I-V measurement using AM1.5 spectra. Conversion efficiency of our cells were between 5.61% and 6.45%.

• E2M - 전기 전자와 첨단 소재
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• 제9권5호
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• pp.498-505
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• 1996

In the present work, we have developed the simulator to optimize the process conditions of the AR(antireflection) and HR(high-reflection) coatings for the high power laser diode. The simulator can run on the PC. After making the simple optical model, we establish the Maxwell equations for the model by the operator conversion. By using the Mathematica, we derive a matrix for the multilayer system by applying the equations to the model and optimize the AR and HR coating process conditions by obtaining the reflection rate from the matrix. We also prove the validity of the simulator by comparing the simulation with the characteristics of the laser diode which is AR and HR coated according to the optimized conditions.

• Transactions on Electrical and Electronic Materials
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• 제4권3호
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• pp.29-33
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• 2003

Tri-crystalline silicon wafers have three different orientations and three-grain boundaries. In this paper, tri-crystalline silicon (tri-Si) wafers have been used for the fabrication of buried contact solar cells. The optical and micro-structural properties of these cells after texturing in KOH solution have been investigated and compared with those of cast mult- crystalline silicon (multi-Si) wafers. We employed a cost effective fabrication process and achieved buried contact solar cell (BCSC) energy conversion efficiencies up to $15\%$ whereas the cast multi-Si wafer has efficiency around $14\%$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.176-180
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• 2003

Tri-crystalline silicon (Tri-Si) wafers have three different orientations and three grain boundaries. In this paper, tri-Si wafers have been used for the fabrication of buried contact solar cells. The optical and micro-structural properties of these cells after texturing in KOH solution have been investigated and compared with those of cast multi-crystalline silicon (multi-Si) wafers. We employed a cost effective fabrication process and achieved buried contact solar cell (BCSC) energy conversion efficiencies up to 15% whereas the cast multi-Si wafer has efficiency around 14%.

• 대한전기학회논문지
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• 제38권10호
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• pp.795-804
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• 1989

A parallel analog-to digital converter with neuron-like elements is designed and optically implemented. Its operation principle is based on the simultaneous estimation of bit values for a given analog input. The architecture of the proposed analog-to-digital converter is simpler than that of an earlier one designed by the energy minimization technique, and its digital output is independent of the initial state. Mixed binary-to-full binary converters are also designed by using out analog-to-digital converters as basic computing elements. These converters have simple structures and fast conversion times compared with earlier ones.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.274-277
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• 1996

This paper describes the realization of the full-color to the degree of nearest white light by compounding high brightness Red, Green and Blue LEDs with appropriate proportional index. Once these three colors; red, green and blue are mixed, they are genearlly additive mixing and produce white light color contrasted to negative mixing. The luminous efficiency is defined as the product of the efficiency(lm/w), which indicates the degree of perceptual response by the human eye to unit energy(W) of light emitted by an active display devises and as the conversion efficiency of the device from electric power consumed to optical energy produced. We will deduce the each number of LEDs theoretically and design several shapes of LED displays for the full-color. Finally theoretical predictions will be compared with the measured data with different type of display designs.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.221-222
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• 2008

In Crystalline Si solar cells, Anti-Reflection Coating is contribute to improvement in energy conversion efficiency due to decrease of optical loss and recombination owing to surface passivation. Porous Si is formed electrochemical etching that uses chemical solution and anodization etching. So It gives that advantage in rapid process time and without high cost equipment. In this paper, We compare Porous Si with $SiO_2$/SiNx ARC and analyze that by anti-reflection coating.

• Current Optics and Photonics
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• 제8권3호
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• pp.300-306
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• 2024

To solve the nozzle swing angle non-contact measurement problem, we present a nozzle pose estimation algorithm involving weighted measurement uncertainty based on rotation parameters. Firstly, the instantaneous axis of the rocket nozzle is constructed and used to model the pivot point and the nozzle coordinate system. Then, the rotation matrix and translation vector are parameterized by Cayley-Gibbs-Rodriguez parameters, and the novel object space collinearity error equation involving weighted measurement uncertainty of feature points is constructed. The nozzle pose is obtained at this step by the Gröbner basis method. Finally, the swing angle is calculated based on the conversion relationship between the nozzle static coordinate system and the nozzle dynamic coordinate system. Experimental results prove the high accuracy and robustness of the proposed method. In the space of 1.5 m × 1.5 m × 1.5 m, the maximum angle error of nozzle swing is 0.103°.