• Korean Journal of Remote Sensing
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• v.21 no.4
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• pp.341-369
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• 2005

Hyperspectral images have emerged as a new and promising remote sensing data that can overcome the limitations of existing optical image data. This study was designed to provide a comprehensive review on definition, data processing methods, and applications of hyperspectral data. Various types of airborne, spaceborne, and field hyperspectral image sensors were surveyed from the available literatures and internet search. To understand the current status of hyperspectral remote sensing technology and research development, we collected several hundreds research papers from international journals (IEEE Transactions on Geoscience and Remote Sensing, International Journal of Remote Sensing, Remote Sensing of Environment and AVIRIS Workshop Proceedings), and categorized them by sensor types, data processing techniques, and applications. Although several hyperspectral sensors have been developing, AVIRIS has been a primary data source that the most hyperspectral remote sensing researches were relied on. Since hyperspectral data have very large data volume with many spectral bands, several data processing techniques that are particularly oriented to hyperspectral data have been developed. Although atmospheric correction, spectral mixture analysis, and spectral feature extraction are among those processing techniques, they are still in experimental stage and need further refinement until the fully operational adaptation. Geology and mineral exploration were major application in early stage of hyperspectral sensing because of the distinct spectral features of rock and minerals that could be easily observed with hyperspectral data. The applications of hyperspectral sensing have been expanding to vegetation, water resources, and military areas where the multispectral sensing was not very effective to extract necessary information.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1769-1771
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• 2004

가스절연 개폐장치(GIS)용 극초단파 부분 방전 측정장치에 다양하게 사용 할 수 있는 외장형 부분 방전 (PD) 센서를 제작하였다. Fat-dipole, 대수주기(log-periodic), spiral 및 log-spiral 형 패치안테나를 이용한 외장형 PD 센서의 주파수 특성과 검출감도를 기본 Dipole형 센서와 비교하였다. 제작된 센서는 170kV 단상 GIS의 스페이서에 장착하여 5 pC PD에 대한 각 센서의 주파수 특성과 감도를 측정 하였다.

• Journal of the Korean Society of Radiology
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• v.17 no.4
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• pp.625-631
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• 2023

The important requirement of industrial dynamic X-ray detector operating under high tube voltage up to 450 kVp for 24 hours and 7 days is to obtain significantly high radiation resistance. This study presents the radiation resistance characteristics of various thin film transistors (TFTs) with a-Si, poly-Si and IGZO semiconducting layers. IGZO TFT offering dozens of times higher field effect mobility than a-Si TFT was processed with highly hydrogenated plasma in between IGZO semiconducting layer and inter-layered dielectric. The hydrogenated IGZO TFT showed most sustainable radiation resistance up to 10,000Gy accumulated, thus, concluded that it is a sole switching device in X-ray imaging sensor offering dynamic X-ray imaging at high frame rate under extremely severe radiation environment such as automated X-ray inspection.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.3
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• pp.240-245
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• 2013

Each pixel of InfraRed(IR) sensor differently responds to IR light as time elapses or the sensor on/off operation is repeated. As a result, the quality of IR sensor image is deteriorated, and therefore NUC(Non-uniformity Correction) is periodically needed for IR sensor. In this paper, in order to perform NUC in the Satellite, on-board V-grooved blackbody is designed with a baffle so that the emissivity of black body is to be higher than 0.995 as well as the temperature deviation is less than $1^{\circ}C$ in the range of the infrared wave length from 3.3 to $5.2{\mu}m$. To check its performance, the emissivity and the surface temperature of the blackbody by TRT(Transfer Reference Thermometer) and IR Micrometer scanner are measured, respectively. From the results, black body design is verified and the uncertainty of NUC is estimated through the measurement results.

• Journal of Practical Engineering Education
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• v.8 no.2
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• pp.111-120
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• 2016

Education equipment for field programmable gate array (FPGA) design of sensor-based IOT (Internet Of Thing) system is introduced. Because sensors have different interfaces, several types of interface controller on FPGA need. Using this equipment, several types of interface controller, which can control ADC (analog-to-digital converter) for analog sensor outputs and $I^2C$ (Inter-Integrated Circuit), SPI (Serial Peripheral Interface Bus), and GPIO (General-Purpose Input/Output) for digital sensor outputs, can be designed on FPGA. Image processing hardware using image sensors and display controller for real and image-processed images or videos can be design on FPGA chip. This equipment can design a SOC (System On Chip) consisting of a hard process core on Linux OS and a FPGA block for IOT system which can communicate with wire and wireless networks. Using the education equipment, an example of hardware design using image sensor and accelerometer is described, and an example of syllabus for "Digital system design using FPGA" course is introduced. Using the education equipment, students can develop the ability to design some hardware, and to train the ability for the creative capstone design through conceptual, partial-level, and detail designs.

• Korean Journal of Remote Sensing
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• v.24 no.6
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• pp.631-639
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• 2008

This study presents an approach to synthesize hyperspectral images of lower resolution at a higher resolution using the high resolution images acquired from a sensor of commercial satellites. The proposed method was applied to the reconstruction of EO-1 Hyperion images using the images acquired from IKONOS sensor. Based on the FitPAN-Mod pansharpening technique (Lee, 2008b), the hyperspectral images of 30m resolution were reconstructed at 1m resolution of IKONOS panchromatic image. In this study, the synthesized hyperspectral images of 50 bands, whose wavelengths range in the wavelength of panchromatic sensor, were generated from the three stages of high resolution reconstruction using FitPAN-Mod. The experimental results show that the proposed method effectively integrates the spatial detail of the panchromatic modality as well as the spectral detail of the hyperspectral one into the synthesized image. It indicates the proposed method has a potential as a technique to produce alternative images for the images that would have been observed from a hyperspectral sensor at the high resolution of commercial satellite images.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.04a
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• pp.166-175
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• 1991

공구수명에 관한 신뢰성 높은 기준 절삭데이타의 수집은 기계가공시스템을 설계, 운영하는데 중요한 것이다. 이제까지 발표된 절삭공구의 마모측정용 센서로는 절삭저항, AE센사, 진동, 절삭온도 등이 있으며, 이 센서들은 공구마모 특히 플랭크 마모(flank wear) 와 간접적인 관계를 갖고서 별도의 사전 절삭실험에 의해 마모량과 신호 level의 상관관계 및 조정이 필요하기 때문에 본 연구팀에서는 직접적으로 공구마모 상태를 검출하고, 신뢰성이 높은 절삭공구의 마모정보를 얻기 위해 최근 그 응용범위가 확대되고 있는 영상처리기술을 응용한 공구마모 측정장치를 구성하였다.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.231.2-231.2
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• 2012

원격탐사를 위한 지구관측용 전자광학 카메라는 높은 해상도, 넓은 관측 폭 및 높은 선명도를 제공하기 위하여 부피가 크고 무거우며, 큰 전력을 소모하여, 위성본체의 대부분을 차지하도록 개발된다. 그러나, 달 탐사를 위해 달 궤도선이나 달 착륙선에 장착되는 전자광학 카메라는, 고해상도의 고성능을 가지도록 개발되기 보다는, 다기능의 집적도 높은 소형카메라로 개발되는 것이 일반적이다. 이에 따라, 달 탐사용 다기능 전자광학 카메라 개발을 위한 기술검증을 위하여 지상모델이 개발되었다. 본 카메라는 CMOS 센서를 사용하여 컴팩트하게 설계하였고, 스테레오 영상생성을 위해 두 개의 카메라가 동시에 운영되며, 줌 기능을 구현하여 다양한 조건에서도 영상획득이 가능하도록 설계 되었다. 또한 달 궤도선과 착륙선에서 1D 관측 및 2D 관측이 선택적으로 가능하도록 설계되었다. 개발된 지상모델은 실험실에서 수행하는 통상적인 기능 및 성능시험을 수행하였고, 스테레오 영상의 생성기능 등의 검증을 위하여 야외에서 카메라를 정속으로 회전하며 push broom 방식의 1D 촬영모드에 대한 시험을 수행한다. 또한, 항공촬영을 통해 1D 및 2D 촬영을 수행하여, 영상데이터의 처리 및 스테레오 영상데이터 생성 등의 검증 단계를 거친다. 본 논문 발표에서는 다기능의 전자광학 카메라를 지상에서 동작시켜 실제영상을 뽑아내고, 생성된 데이터를 처리하여, 설계된 카메라의 여러 가지 기능들에 대해 검증하는 방법들에 대해 정리 및 발표한다. 즉, 달 궤도에 맞게 설계된 카메라의 노출시간 등을 조절하고, push broom 방식을 모사하기 위하여 카메라를 정속으로 회전시켜 영상을 획득하여 다양한 카메라의 기능을 검증하였다.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.90.2-90.2
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• 2010

흙막이 굴착 및 절취사면의 보강공법으로 많이 적용되고 있는 앵커의 장력을 측정하는 전기저항식 로드셀과 스트레인게이지, 바이브레이팅 와이어 (vibrating wire) 타입의 모니터링 방법은 안전관리를 위한 장기적인 모니터링에 한계를 가지고 있어 이를 개선할 수 있는 방안으로 광섬유 센서를 이용하여 강연선의 변형률을 측정할 수 있는 스마트 텐던이 개발되었다(김재민 등, 2007). 앵커를 구성하는 7연 강연선(텐던)의 중앙케이블에 삽입된 광섬유브래그격자(Fiber Bragg Grating ; FBG)센서는 기존 스트레인게이지 타입에 비해 크기가 작고 내구성이 우수하며 전자기파에 의한 노이즈 발생이 없고 하나의 리드선으로 다중점 측정(multiplexing)이 가능하여 장기모니터링에 효과적인 장점이 있다. 본 연구에서는 FBG센서를 내장한 스마트 텐던을 실대형(Prototype) 앵커(L=11.5m)에 적용하여 현장 인발실험에 의해 시공중 장력 모니터링을 수행하고 로드셀 측정결과와 비교하였고 정착부에 설치된 FBG 센서로부터 앵커의 하중전이 계측을 수행하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.5
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• pp.455-462
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• 2016

Output Characteristics of the spaceborn image sensor such as infrared(IR) sensor are varied according to time elapses and sensor repetition on/off operation. As a result, the quality of IR sensor image is decreased. Therefore, spaceborne image sensor require a periodic calibration using a black body system by correcting a non-uniformity of the sensor. In this paper, we proposed a MEMS-based black body system that can implement the high temperature uniformity at various standard temperatures ranging from low to high temperature and easily estimate the representative surface temperature. In addition, it has advantages lightweight, low-power and high accuracy. The feasibility of the proposed MEMS-based black body system was verified through the thermal analysis.