• 천문학회보
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• 제39권2호
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• pp.69.2-69.2
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• 2014

We present space-based near-IR (NIR) and optical photometry of globular clusters (GCs) of 16 early-type galaxies in the Fornax and Virgo Clusters. The NIR imaging data for the nearby galaxies was acquired with the IR Channel of the Wide Field Camera 3 (WFC3/IR) in the F110W ($J_{110}$) and F160W ($H_{160}$) bandpasses. We introduce the full sample of our WFC3/IR program, describe data reductions and photometric measurements including GC candidate selection criteria, and then show selected GCs' color-magnitude diagrams. The tilted features in the diagrams related to the morphological types of host galaxies are discussed in the context of galaxy formation and evolution histories. Combining F475W ($g_{475}$) and F850LP ($z_{850}$) data taken from the Advanced Camera for Surveys Virgo and Fornax Cluster Surveys with our NIR data, we investigate the bimodality in optical-NIR color distribution and the nonlinear feature of the optical-NIR color relation as a function of optical color for these extragalactic GC systems.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.249-256
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• 2001

Optical Color Corescanner firstly developed by DMT-GeoTec, Germany and further upgraded through the Korea-Germany joint project is capable of duplicating the core surfaces. The tool uses a digital CCD line camera. As the core is rotated by an electric motor, the camera scans the uppermost line, everytime with a circumferential increment of up to 0.05mm(20pixels/mm) and hence a complete 360$^{\circ}$ unwrapped image(core image) is produced. This paper illustrated diverse research benefits of such core images from several test sites in our country. All scanned images could be stored as a data-base one and easily used with software facilities \circled1 to evaluate a percental distribution of mineral components or grain size etc. not only for the rock classification but also for e.g. the assessment of building stones, \circled2 to study potential reservoirs as a hydrocarbon indicator using ultraviolet fluorescence reflection from cores, \circled3 to facilitate the qualitative and quantitative analysis of fractures, \circled4 to evaluate the fractures and thin bedded reservoirs using spectral color responses. Based on abundant scanning experiments, it would seem that this imaging work should lead to reflecting the future trend in underground survey toward a more comprehensive understanding of the properties and behaviors of in situ rocks.

• 천문학회지
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• 제45권1호
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• pp.7-17
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• 2012

Y-band is a broad passband that is centered at ~1 ${\mu}m$. It is becoming a new, popular window for extragalactic study especially for observations of red objects thanks to recent CCD technology developments. In order to better understand the general characteristics of objects in Y-band, and to investigate the promise of Y-band observations with small telescopes, we carried out imaging observations of several extragalactic fields, brown dwarfs, and high redshift quasars with Y-band filter at the Mt. Lemmon Optical Astronomy Observatory and the Maidanak observatory. From our observations, we constrain the bright end of the galaxy and the stellar number counts in Y-band. We also test the usefulness of high redshift quasar (z >6) selection via i - z - Y color-color diagram, to demonstrate that the i - z - Y color-color diagram is effective for the selection of high redshift quasars even with a conventional optical CCD camera installed at a 1-m class telescope.

• 대한원격탐사학회지
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• 제15권4호
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• pp.367-375
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• 1999

This paper describes the development, operations, and applications of ROCSAT-l and its Ocean Color Imager (OCI) remote-sensing payload. It is the first satellite program of NSPO. The satellite was successfully launched by Lockheed Martin's Athena on January 26, 1999 from Cape Canaveral, Florida. ROCSAT-l is a Low Earth Orbit (LEO) experimental satellite. Its circular orbit has an altitude of 600km and an inclination angle of 35 degrees. The satellite is designed to carry out scientific research missions, including ocean color imaging, experiments on ionospheric plasma and electrodynamics, and experiments using Ka-band (20∼30GHz) communication payloads. The OCI payload is utilized to observe the ocean color in 7 bands (including one redundant band) of Visible and Near-Infrared (434nm∼889nm) range with the resolution of 800m at nadir and the swath of 702km. It employs high performance telecentric optics, push-broom scanning method using Charge Coupled Devices (CCD) and large-scale integrated circuit chips. The water leaving radiance is estimated from the total inputs to the OCI, including the atmospheric scattering. The post-process estimates the water leaving radiance and generates different end products. The OCI has taken images since February 1999 after completing the early orbit checkout. Analyses have been performed to evaluate the performances of the instrument in orbit and to compare them with the pre-launch test results. This paper also briefly describes the ROCSAT-l mission operations. The spacecraft operating modes and ROCSAT Ground Segment operations are delineated, and the overall initial operations of ROCSAT-l are summarized.

• 전자공학회논문지
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• 제50권8호
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• pp.215-224
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• 2013

본 논문에서는 고해상도 영상에서 호모그래피를 효율적으로 추정하는 방법을 제안하였다. 호모그래피를 정확하게 추정하는 것은 영상 정합 기술에서 가장 중요한 부분이다. 하드웨어의 급속한 발전으로 고해상도 영상을 쉽게 취득 할 수 있게 되었지만, 데이터의 크기가 증가함에 따라 정확한 일치관계를 추정하는데 많은 계산량이 요구되었다. 또한, 고해상도의 영상에서 확률적으로 부정확한 호모그래피가 추정되는 문제가 발생하였다. 따라서 우리는 원 영상을 각 스케일별로 다운 샘플링한 다수의 영상을 생성하여 각 다운 샘플링된 영상에 해당하는 호모그래피를 추정한 후 투영 오차가 가장 작은 것을 선택하여 원 영상에 적용할 수 있게 보정할 수 있는 방법을 제안하였다. 또한, 영상을 정합하는 과정에서 기준 영상과 대상 영상의 색상 톤의 차이가 큰 경우에는 중첩영역의 지역 정보만을 이용하여 기준 영상과 대상 영상의 색상 톤을 일치시키는 방법을 제안하였다. 실험 결과 기존의 방법보다 3.2M 픽셀의 해상도 영상에서 약 3배, 8M 픽셀의 해상도 영상에서 약 5배 이상 빠른 결과를 얻을 수 있음을 확인하였다. 이는 입력 영상의 해상도가 커질수록 제안한 방법의 효과가 더 커진다는 것을 보여준다.

• 한국임상수의학회지
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• 제38권3호
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• pp.163-168
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• 2021

A 6-year-old, spayed female, Maltese dog with tachypnea and dry cough was presented to Gyeongsang National University Veterinary Medical Teaching hospital. On physical examination, its respiration rate was 132 per minute. Decreased partial pressure of oxygen, partial pressure of carbon dioxide, and hyperlactatemia were found on arterial blood gas analysis. Its diastolic blood pressure was 80 mmHg. Auscultation revealed arrhythmia. Electrocardiogram revealed P pulmonale, P mitrale, and ventricular premature complexes. Thoracic radiographs revealed mild enlargement of both atrium and moderate enlargement of the left ventricular. There was also a moderate alveolar pattern in the right and caudal part of the left cranial lung lobe. Two-dimensional echocardiography showed enlargement of generalized four chambers without remarkable findings of valvular degeneration. M-mode echocardiography showed decreased left ventricular fractional shortening and enlarged left ventricular internal diameter at both end-systolic and end-diastolic. Color-flow Doppler imaging revealed eccentric turbulent flow starting below the left ventricular outflow tract and extending into the left atrium during systole. Spectral Doppler recordings revealed a high velocity flow through the mitral, tricuspid, aorta, and pulmonic regurgitation. Restrictive transmitral flow revealed high E-wave velocity, short E-wave deceleration time, and reduced A-wave velocity. There was also low ejection velocity thorough left ventricular out tract flow. Based on echocardiographic examination, dilated cardiomyopathy was the tentative diagnosis. The dog was medicated with inotropes, angiotensin converting enzyme inhibitor, and diuretics. At the 10-day following-up, the dog died suddenly. This report describes echocardiographic diagnosis and prognosis of dilated cardiomyopathy rarely reported in small breed dogs.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2001년도 정기총회 및 학술대회
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• pp.149-154
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• 2001

멀티미디어 정보표현 기술인 MPEG-7 표준이 빠른 속도의 진전을 보임에 따라 이를 활용한 검색 기술 개발도 활발히 진행 중에 있다 방대한 량의 동영상 내용 검색 기술 연구에 있어서 우선적으로 고려되어야 할 부분이 내용이 연속되는 프레임들의 분류이다. 이를 위해서는 물리적인 장면전환이 이루어지는 부분에 대한 실시간 자동 cut detection 기술 및 이 컷 프레임 영상에 대한 내용 기술을 자동적으로 수행할 필요성이 있다. 각 컷 프레임의 자동 내용 기술의 전처리로써 본 논문에서는 장면전환이 생기는 프레임의 영상의 어떠한 정보도 사전 정보로 취하지 않고 사용자의 개입이 없는 상황에서 영상의 컬러 특성 및 에지 정보만을 가지고 shape 영역 segmentation을 자동으로 실행하는 방법을 제안한다. 제안한 방법의 성능은 segmentation된 영상과 원 영상과의 영역비교를 통한 유사도에 의해 평가하며, 시뮬레이션 결과에서 제안한 알고리즘은 평균 90%이상의 영역 분할이 정확하게 됨을 알 수 있었고, 컬러의 구분이 명확하지 않은 자연영상에서도 robust한 segmentation 결과를 나타냄을 본 연구를 통하여 알 수 있었다.

• 대한기관식도과학회지
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• 제17권1호
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• pp.14-18
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• 2011

The diagnosis and treatment of early gastrointestinal cancers is the gastroenterologists' mission because of national cancer screening program in South Korea. The detection of early cancers is emphasized, because these were previously treated with surgical treatment can be currently cured with endoscopic treatment. Gastroenterologists who achieved at least on some level can make an exact diagnosis regardless of what type of endoscopy, but generally, there are some required conditions for an optimal diagnosis. First, clinically important lesions have to be detected easily. Second, the border and morphology of lesions have to be characterized easily. Third, lesions have to be diagnosed exactly. Precancers and early cancers are often subtle and can pose a challenge to gastroenterologists to visualize using standard white light endoscopy. The use of dye solutions aids the diagnosis of early gastrointestinal cancers, however, it is a quite cumbersome to use dye solutions all the time and the solution often bothers the exact observation by pooling into the depression or ulceration of the lesion. To overcome this weakness, newer endoscopes are now developed so called "image enhanced endoscopy" using optical and/or electronic methods such as narrow band imaging (NBI), autofluorescence imaging (AFI), i-scan, flexible spectral imaging color enhancement (FICE) and confocal endomicroscopy (CLE).

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2002년도 제7차 학술대회 초록집
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• pp.106-106
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• 2002

Purpose： The purposes of our study are (1) to develop a brain phantom which can be used for multimodal image registration, (2) to evaluate the accuracy of image registration with the home-made phantom. Method： A brain phantom which could be used for image registration technique of CT-MR and CT-SPECT images using chamfer matching was developed. The brain phantom was specially designed to obtain imaging dataset of CT, MR, and SPECT. The phantom had an external frame with 4 N-shaped pipes filled with acryl rods for CT, MR imaging and Pb rods for SPECT imaging. 8 acrylic pipes were inserted into the empty space of the brain phantom to be imaged for geometric evaluation of the matching. Accuracy of image fusion was assessed by the comparison between the center points of the section of N-shaped bars in the external frame and the inserted pipes of the phantom. Technique with partially transparent, mixed images using color on gray was used for visual assessment of the image registration process.

• Journal of Biosystems Engineering
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• 제26권2호
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• pp.169-176
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• 2001

Defect of apple was depreciated the product value and causes storage disease seriously. To detect the defect of ‘Fuji’apple with machine vision system, the optical characteristics of defect should be investigated. In this research, absorbance spectra of defect were acquired by spectrophotometer in the range of visible and NIR region(400∼1,100nm) and L*a*b* color values were also acquired by colorimeter. NIR machine vision system was constructed with B&W camera, frame grabber, 16 tungsten-halogen lamps, variable focal length lens and NIR bandpass filter which was mounted to lens outward. Average gray values of defect at 15 NIR wavelength were acquired and the significant NIR wavelength was selected by comparing Mahalanobis distance between sound and defective apple. As the result of Mahalanobis distance analysis, the significant wavelength to discriminate the defectives in ‘Fuji’apple were found to be 720nm for scab and 970nm for bruise and cuts and 920nm was also effective regardless of defective types.