• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.7
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• pp.682-687
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• 2011

Calibration mirror mechanism has been widely used for on-board calibration with black body. The calibration mirror is deployed to reflect the radiation energy from the black body to the image sensor for calibrating the sensor system. After the calibration, the calibration mirror is stowed not to hide a main optical path. It also has a fail-safe function which can stow the mirror by just removing the input power of motor when the calibration mirror is stopped at certain position during the calibration. In the present work, the operation concept, design, torque analysis and functional test results of the calibration mirror mechanism with the aforementioned function have been introduced and investigated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.493-496
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• 2000

This study is about the design and fabrication of optical voltage sensor modules improved in the insulation reliability, where we adopted the space-division voltage system using the auxiliary electrodes to apply the uniform electric fields to the BSO, the device of which the polarization state varies with the variation of refractive index in the electric fields. We measured the output of fiber-Optic Voltage Sensors with the temperature changes in the thermostatic oven. And we measured the output of Fiber-Optic Voltage Sensors after setting its up in the disttibuion automated switch being apply 60Hz alternating voltage from 6.6kV to 17.BkV. In result, measured error characteristic is good, so we can judge it is applicable to the practical case

• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.176-181
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• 2009

This study is part of a project to develop and improve mooring systems for oceanographic use that include an electro-optical sensor, 1MHz Nortek Aquadopp Doppler Profiler and AIRMAR multipurpose Sensor. The adaption of Doppler current profilers to measure directional wave spectra has provided a new instrumentation approach to coastal and nearshore oceanographic studies. The HEIOB is developed are light weight and of a compact design, and can be easily installed in marine environment. Since there are no base station and gateways in marine environments, we selected CDMA and Orbcomm to send the data information. Therefore, the data can be sent by either e-mail service or Short Message Service (SMS). This paper will present some of scientific sensor results regarding real-time oceanographic and meteorological parameters such as wind spend, wind direction, wave direction, and etc. The modeling and test results highlight the engineering challenges associated with designing these systems for long lifetimes. It can also be used in future application to build wave observation buoy network in real-time using multiple ubiquitous buoys that share wave data and allow analysis of multipoint, multi-layer wave profiler.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.501-502
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• 1992

This paper deals with the experiment of CW YAG laser for processing. The YAG laser is spotted very small size beam compared with $CO_2$ laser having short wave-length. That is used broadly in material processing because of easy reaction to the materials, and the maintenance is very simple. The power delivery and focussing is done conventional optical components, and splitting beam is used many point stop-welding. In these studies, especial interest is nesessary to perpare for future technology. Our study aims to develop the YAG laser system and to accumulate design and construction technology. In basic experiments, we obtain the maximum output power of 50 W with the single elliptical cylinder.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1296-1299
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• 2002

We implemented a CD signal processor operated on a CAV 48-speed CD-ROM drive into a VLSI. The CD signal processor is a mixed mode monolithic IC including servo-processor, data recovery, data-processor, and I-bit DAC. For servo signal processing, we included a DSP core, while, for CAV mode playback, we adopted a PLL with a wide recovery range. Data processor (DP) was designed to meet the yellow book specification.［2］So, the DP block consists of EFM demodulator, C1/C2 ECC block, audio processor and a block transferring data to an ATAPI chip. A modified Euclid's algorithm was used as a key equation solver for the ECC block To achieve the high-speed decoding, the RS decoder is operated by a pipelined method. Audio playability is increased by playing a CD-DA disc at the speed of 12X or 16X. For this, subcode sync and data are processed in the same way as main data processing. The overall performance of IC is verified by measuring a transfer rate from the innermost area of disc to the outermost area. At 48-speed, the operating frequency is 210 ㎒, and this chip is fabricated by 0.35 um STD90 cell library of Samsung Electronics.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.01a
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• pp.229-232
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• 2011

최근 스마트 디바이스 기반의 다양한 콘텐츠 제작 공급에 대한 새로운 마켓 시장 형성과 태블릿 디바이스 기반의 전자책 시장 규모의 확대에 따른 새로운 유형의 디지털 콘텐츠 시장이 형성되고 있다. 디지털 미디어는 정보환경 범위를 종이의 범위에서 벗어나 매체와 연계한 다양한 형태로의 변화뿐만 아니라 서술 방식과 소통방식의 방법에도 변화를 발생하였다. 그리고 지면에서 국한된 아날로그 매체의 물리적, 공간적, 시간적인 한계를 뛰어넘어 다양한 콘텐츠를 손쉽게 접근할 수 있게 만들었다. 이런 환경에서 본문검색 서비스는 아날로그와 디지털 매체의 상호 공존관계를 형성할 수 있다. 본 논문에서는 그림종이문서를 본문검색이 가능한 이미지형태의 디지털문서로 변환해주는 디지털라이징 시스템으로 문자위치정보를 포함하는 광학문자인식(OCR)기능과 인식된 문자의 오류를 수정하는 에디터기능을 통해 추출된 내용을 XML형태로 제공하는 본문검색 시스템을 제안한다. 특히, 문자인식 후처리 공정에서 복수의 관학문자인식(OCR)엔진을 통해 결과 비교와 문자위치 정보 확인 및 편집, 맞춤법 검사 등의 특화된 기능 등은 본 논문에서 가지는 강점으로 디지털문서 구축에 소요되는 시간과 비용을 혁신적으로 절감시켜준다.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.2
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• pp.154-159
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• 2013

In this paper, the effect of bolt clamping force and form accuray of contact surface between mirror and mount on mirror surface was studied. Normally, mirror used in reflecting optical system was assembled with mount by bolts or adhesive. In this case, the tension caused by bolt clamping force or adhesive force may distort the mirror surface. Also, form accuracy error of the contact surface have a negative impact on wrenched mirror surface which assembled by bolts or adhesive. In this study, stress and distorted displacements on mirror surface were analyzed according to the different contact surface form accuracies and bolt clamping forces by using the finite element analysis method.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.10
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• pp.99-106
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• 2002

This paper proposes an error compensation method that improves accuracy with geometry information of injection molding parts. Geometric information can give an improved accuracy in reverse engineering. Measuring data can not lead to get accurate geometric model, including errors of physical parts and measuring machines. Measuring data include errors which can be classified into two types. One is molding error in product, the other is measuring error. Measuring error includes optical error of laser scanner, deformation by probe forces of CMM and machine error. It is important to compensate these in reverse engineering. Least square method (LSM) provides the cloud data with a geometry compensation, improving accuracy of geometry. Also, the functional shape of a part and design concept can be reconstructed by error compensation using geometry information.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.04a
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• pp.206-209
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• 2003

The purpose of AR and HR coating is acquire the very low reflection rate and the high reflection rate through the deposition of a thin film using the refraction ofmaterial. Basically if the high refractive material and the low refractive material are chosen and the condition for the experiment is determined, then we solve theproject with the optical design and multi thin film coating. First of all, we choose $SiO_2$for the low refractive material and $TiO_2$ for the high refractive material and apply Sputtering System easy to control the refraction rate and excellent in reconstruction to the equipment of thin film multiplication. For the control of the refraction rate and growth rate we modify RF Power and the ratio of Gas(Ar:O2), And we use Ellipsometer for estimation and analysis of the refraction rate and growth rate and AFM&SEM for the analysis of surface and component.

• Current Industrial and Technological Trends in Aerospace
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• v.6 no.1
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• pp.124-134
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• 2008

The rising demand for the high efficiency and high covertness in UAV motivates the miniature design of the high performing mission sensors, or payloads. One of the promising payload sensors, EO/IR sensor has evolved satisfying its demands and became the main stand-alone mission sensor for 200kg-range UAV. One aspect in development of EO/IR sensor concerns lack of specification criterions to represent its performance. Even though the high demand and competition among each manufacturer caused EO/IR features subject to rapid change collateral to new technology, the datasheets maintained the conventional outdated formats which leave some of the major components in ambiguity. Making comparisons or predicting actual performance with such datasheets is hardly worthwhile; yet, they could be important reference guide for the potential customers what to expect for the upcoming EO/IR. According to UAS Roadmap 2007-2032 published by DoD, one of the main potential customers as well as a main investor of EO/IR technology, EO/IR is expected to play key roll in solving urgent problems, such as see and avoid system. This paper will examine the recent representative EO/IR specialized in UAS missions through datasheets to find out current trend and eventually extrapolate the possible future trend.