• 전자통신동향분석
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• 제33권3호
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• pp.78-88
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• 2018

As the unmanned aerial vehicle industry and its related technologies grow each year, the number of abuse cases caused by drones is increasing. In addition to the invasion of privacy caused by indiscriminate photography, terrorism using unmanned aerial vehicles, which have a low detection probability, high location accuracy, and the capability of targeting people or places, as well as carrying chemicals, radiation materials, and small bombs, is becoming a significant problem around the world. Accordingly, many companies are developing anti-drone solutions that consist of various technologies such as radar, EO/IR cameras, and RF jammers to detect and disable unmanned aerial vehicles. This article briefly introduces the recent R&D trends and technical levels of anti-drone technologies.

• 한국응용과학기술학회지
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• 제18권2호
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• pp.136-141
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• 2001

Naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. In this study, red-sensitizing dye was prepared by the reaction of 2-methyl-3-sulfopropyl-4,5-naphthothiazolium(inner salt) with triethyl orthoacetate in the presence of triethylamine. The product was identified by using various analytical tools such as Elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, Mass spectrometer, $^{1}H-NMR$ spectrometer, TGA and DSC. The maximum absorption peak in methanol solvent was 573nm. Therefore, it was concluded that naphthothiazolo carbocyanine dye can be used as red0sensitizing dye for the spectral sensitization of photographic emulsion.

• 전자공학회논문지
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• 제50권9호
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• pp.127-135
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• 2013

저조도 환경에서 카메라로 영상을 획득하기 위해 일반적으로 가시광 플래시를 사용하거나 장노출 기법을 사용하게 된다. 그러나 가시광 플래시를 사용할 때 플래시 광에 의한 색 왜곡이나 적목 현상, 눈부심에 의한 거부감을 발생시킨다. 또한 장노출을 사용하게 되면 물체의 움직임에 의한 흔들림 현상이 발생하게 된다. 따라서 최근에는 이러한 단점을 극복하고, 저조도 환경에서 고화질의 영상을 획득하기 위하여 멀티 스팩트럴 플래시(Multi-spectral flash image)를 이용하여 영상을 획득하는 방법이 소개되었다. 이 방법은 가시광과 UV/IR스펙트럼의 다섯 채널을 이용하여 가시광영상의 색 정보와 UV/IR 스팩트럼 영상의 세부정보를 최적화하여 영상을 획득하는 방법이다. 하지만, 픽셀 기반의 최적화 과정에 있어 색 왜곡과 다른 잡음을 발생시키게 된다. 따라서 본 논문에서는 이러한 색 왜곡과 잡음을 개선하기 위해 영역 기반의 가중치 맵을 최적화 방법에 적용하여 색 왜곡을 개선하는 알고리즘을 제안한다. 먼저, 영상에 대하여 Canny 에지 검출 방법을 사용하여 영상의 윤곽을 검출하였다. 이를 가중치 맵으로 최적화방법에 적용함으로, 세부 영역에 대하여 UV/IR 플래시 영상의 정보에 가중치를 부여하고, 평탄한 영역에 대하여 가시광 영상의 색 정보를 가중치를 부여하여 색 왜곡을 개선하였다. 제안한 방법을 평가하기 위하여 실험을 통하여 제안한 방법과 이전방법을 비교하였고, 객관적 평가와 주관적 평가 모두 제안한 방법이 우수한 성능을 나타내었다.

• 대한원격탐사학회지
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• 제20권5호
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• pp.337-351
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• 2004

Our laboratory originally developed the compact, multi-spectral, automatic aerial photographic system PKNU3 to allow greater flexibility in geological and environmental data collection. We are currently developing the PKNU3 system, which consists of a color-infrared spectral camera capable of simultaneous photography in the visible and near-infrared bands; a thermal infrared camera; two computers, each with an 80-gigabyte memory capacity for storing images; an MPEG board that can compress and transfer data to the computers in real-time; and the capability of using a helicopter platform. Before actual aerial photographic testing of the PKNU3, we experimented with each sensor. We analyzed the lens distortion, the sensitivity of the CCD in each band, and the thermal response of the thermal infrared sensor before the aerial photographing. As of September 2004, the PKNU3 development schedule has reached the second phase of testing. As the result of two aerial photographic tests, R, G, B and IR images were taken simultaneously; and images with an overlap rate of 70% using the automatic 1-s interval data recording time could be obtained by PKNU3. Further study is warranted to enhance the system with the addition of gyroscopic and IMU units. We evaluated the PKNU 3 system as a method of environmental remote sensing by comparing each chlorophyll image derived from PKNU 3 photographs. This appraisement was backed up with existing study that resulted in a modest improvement in the linear fit between the measures of chlorophyll and the RVI, NDVI and SAVI images stem from photographs taken by Duncantech MS 3100 which has same spectral configuration with MS 4000 used in PKNU3 system.