• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.255-258
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• 2008

The DEM (Digital Elevation Model) can be obtained from stereo image pair acquired by LEO satellite. Stereo images may consist of at least two images with different viewing angles to the imaging target for one pass or multiple passes. While each image is generally acquired from each pass in cross-track direction for multiple passes, stereo image pair in along-track direction can be acquired during one pass with attitude control capability for the pitch axis of the satellite. Single pass stereo imaging provides stereo pair image more efficiently on the fact that stereo pair image is generated with less orbit resources and less imaging time consumption. In this paper, the feasibility study result on the stereo pair image collection planning algorithm during single pass is addressed.

• 대한방사선기술학회지:방사선기술과학
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• 제44권1호
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• pp.31-37
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• 2021

This study aim of quantitative assessment of Noise Power Spectrum(NPS) and image characteristics of by acquired the optimal image for noise characteristics and quality assurance by using magnetic resonance imaging(MRI). MRI device was (MAGNETOM Vida 3.0T MRI; Siemense healthcare system; Germany) used and the head/neck shim MR receive coil were 20 channels coil and a diameter 200 mm hemisphere phantom. Frequency signal could be acquired the K-space trajectory image and white image for NPS. The T2 image highest quantitatively value for NPS finding of showed the best value of 0.026 based on the T2 frequency of 1.0 mm-1. The NPS acquired of showed that the T1 CE turbo image was 0.077, the T1 CE Conca2 turbo image was 0.056, T1 turbo image was 0.061, and the T1 Conca2 turbo image was 0.066. The assessment of NPS image characteristics of this study were to that could be used efficiently of the MRI and to present the quantitative evaluation methods and image noise characteristics of 3.0T MRI.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.429-431
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• 2002

Metabolic analysis of biological tissues, the interventional radiology in MRT (Magnetic Resonance Treatment) and for clinical diagnoses, representation of 4-Dimensional (4D) structural information (x,y,z,t) of biological tissues is required. This paper discusses image representation techniques for those 4D MR Images. We have proposed an image reconstruction method for ultra-fast 3D MRI. It is based on image interpolation and prediction of un-acquired pictorial data in both of the real and the k-space (the acquisition domain in MRI). A 4D MR image is reconstructed from only two 3D MR images and acquired a few echo signals that are optimized by prediction of the tissue motion. This prediction can be done by the phase of acquired echo signal is proportioned to the tissue motion. On the other hand, reconstructed 4D MR images are represented as a 3D-movie by using computer graphics techniques. Rendered tissue surfaces and/or ROIs are displayed on a CRT monitor. It is represented in an arbitrary plane and/or rendered surface with their motion. As examples of the proposed representation techniques, the finger and the lung motion of healthy volunteers are demonstrated.

• 한국태양에너지학회 논문집
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• 제33권5호
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• pp.51-59
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• 2013

It is usual to evaluate the performance of the cool roof by measuring in-site rooftop temperature using thermal infra-red camera. The principal advantage of rooftop thermal infrared image acquired in oblique vantage point of super high-rise building as a remote sensor is to provide, in a cost-effective manner, area-wide information required for a scattered rooftop target with different colors, utilizing wide view angle and multi-temporal data coverage. This research idea was formulated by incorporating the concept of traditional remote sensing into rooftop temperature monitoring. Correlations between infrared image of super high-rise building and in-situ data were investigated to compare rooftop surface temperature for a total of four different rooftop locations. The results of the correlations analyses indicate that the rooftop surface temperature by the infrared images of super high-rise building alone could be explained yielding $R^2$ values of 0.951. The visible permanent record of the oblique thermal infra-red image was quite useful in better understanding the nature and extent of rooftop color that occurs in sampling points. This thermal infrared image acquired in oblique vantage point of super high-rise made it possible to identify area wide patterns of rooftop temperature change subject to many different colors, which cannot be acquired by traditional in-site field sampling. The infrared image of super high-rise building breaks down the usual concept of field sampling established as a conventional cool roof performance evaluation technique.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.820-824
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• 2003

One of the most important research areas on remote sensing is spectral unmixing of hyper-spectral data. For spectral unmixing of hyper spectral data, accurate land cover information is necessary. But obtaining accurate land cover information is difficult process. Obtaining land cover information from high-resolution data may be a useful solution. In this study spectral signature of endmembers on ASTER acquired in October was calculated from land cover information on IKONOS acquired in September. Then the spectral signature of endmembers applied to ASTER images acquired on January and March. Then the result of spectral unmxing of them evauateted. The spectral signatures of endmembers could be applied to different seasonal images. When it applied to an ASTER image which have similar zenith angle to the image of the spectral signatures of endmembers, spectral unmixing result was reliable. Although test data has different zenith angle from the image of spectral signatures of endmembers, the spectral unmixing results of urban and vegetation were reliable.

• 디지털콘텐츠학회 논문지
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• 제13권3호
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• pp.421-429
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• 2012

최근 방사선 의료에서 중재적 시술의 확대로 인하여 시술 건수가 증가하고 있으며, 시술자에 따라 방사선 노출이 다르게 나타 날 수 있으며 시술자와 환자가 받는 방사선 피폭의 증가를 가져온다. 본 연구는 2011년 11월 01일부터 2012년 01월 31일 까지 경북지역 S대학 병원에 내원한 303명의 심장내과 환자를 대상으로 중재적 방사선시술을 시행한 시술자 5명에 따른 방사선 노출특성을 비교분석하였다. 투시시간의 경우 5명의 시술의의 평균 투시시간은 697.95초, cumulative DAP(exp)의 경우 평균 환자 면적선량은 $52,730mGycm^2$, total DAP의 경우 평균 환자면적선량은 $104,875.14mGycm^2$, acquired image의 경우 평균 영상은 855.52frame, exposure image의 평균 영상은 802.2frame로 나타나 통계적으로 유의한 차이를 보였다(p<0.05). 장비의 X선 노출 특성 즉, 투시시간, cumulative DAP(fluro), cumulative DAP(exp), total DAP, acquired image, exposure image는 서로 높은 상관관계를 보이나 cumulative DAP(exp)와 acquired runs는 상관관계를 보이지 않았다. 시술자와 가장 큰 비중을 차지하는 것은 투시시간으로 나타나 투시시간이 길어질수록 방사선 피폭이 증가함을 의미한다. 시술시 피폭선량은 시술자에 따라 시술능력과 경험, 시술의 난이도 및 정밀 시술여부와 관련 있으며, 혈관 조영의 횟수와 투시시간이 정해진 것이 아니어서 인위적인 조절이 어려운 부분이라 할 수 있다. 따라서, 중재방사선 절차를 수행하는 의료진의 실질 피폭을 합리적으로 평가하는 시스템이 필요하며, 불필요한 피폭을 줄이기 위해 시술자를 비롯한 방사선 작업종사자에 대한 자체교육과 훈련이 필요할 것으로 사료된다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.109-113
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• 2007

The COMS provides the LRIT/HRIT services to users. The COMS LRIT/HRIT broadcast service should satisfy the 15 minutes timeliness requirement. The requirement is important and critical enough to impact overall performance of the LHGS. HRIT image data is acquired from INRSM output receiving but LRIT image data is generated by sub-sampling HRIT image data in the LHGS. Specially, since LRIT is acquired from sub-sampled HRIT image data, LRIT processing spent more time. Besides, some of data loss for LRIT occurs since LRIT is compressed by lossy JPEG. Therefore, algorithm with the fastest processing speed and simplicity to be implemented should be selected to satisfy the requirement. Investigated sub-sampling algorithm for the LHGS were nearest neighbour algorithm, bilinear algorithm and bicubic algorithm. Nearest neighbour algorithm is selected for COMS LHGS considering the speed, simplicity and anti-aliasing corresponding to the guideline of user (KMA: Korea Meteorological Administration) to maintain the most cloud itself information in a view of meteorology. But the nearest neighbour algorithm is known as the worst performance. Therefore, it is studied in this paper that the selection of nearest neighbour algorithm for the LHGS is reasonable. First of all, characteristic of 3 sub-sampling algorithms is studied and compared. Then, several sub-sampling algorithm were applied to MTSAT-1R image data corresponding to COMS HRIT. Also, resized image was acquired from sub-sampled image with the identical sub-sampling algorithms applied to sub-sampling from HRIT to LRIT. And the difference between original image and resized image is compared. Besides, PSNR and MSE are calculated for each algorithm. This paper shows that it is appropriate to select nearest neighbour algorithm for COMS LHGS since sub-sampled image by nearest neighbour algorithm is little difference with that of other algorithms in quality performance from PSNR.

• Current Optics and Photonics
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• 제3권4호
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• pp.329-335
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• 2019

Wide FOV imaging systems are important for acquiring rich visual information. A conventional catadioptric imaging system deploys a camera in front of a curved mirror to acquire a wide FOV image. This is a cumbersome setup and causes unnecessary occlusions in the acquired image. In order to reduce both the burden of the camera deployment and the occlusions in the images, this study uses a secondary planar mirror in the catadioptric imaging system. A compact design of the catadioptric imaging system and a condition for the position of the secondary planar mirror to satisfy the central imaging are presented. The image acquisition model of the catadioptric imaging system with a secondary planar mirror is discussed based on the principles of geometric optics in this study. As a backward mapping, the acquired image is restored to a distortion-free image in the experiments.

• 한국측량학회지
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• 제17권2호
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• pp.167-176
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• 1999

각종 영상매체와 수치영상처리 기술이 발전함에 따라 수치영상을 이용한 대상물의 정량적 또는 정성적 분석에 관한 연구가 활발히 진행되고 있다. 그러나 높은 정확도의 영상해석에 있어 고해상도의 영상획득 시스템에 대한 의존도가 매우 높은 실정이며 이들은 고가의 장비라는 문제점을 안고 있다. 본 연구에서는 저가의 영상획득 시스템에 의해 획득한 다중영상을 강화ㆍ분석하여 최적의 강화조건을 도출하고 이를 적용하여 3차원 정확도 분석을 실시하였다. 저해상도의 원시영상과 최적의 조건에 의해 강화한 영상을 이용하여 평균 3차원 위치오차를 분석한 결과, 강화영상은 원시영상에 비해 10％정도 향상된 정확도를 보였다.

• 핵의학기술
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• 제12권3호
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• pp.192-198
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• 2008

Purpose: The scan time reduction helps to yield more accurate results and induce the minimization of patient's motion. Also we can expect that satisfaction of examination will increase. Nowdays medical equipment companies have developed various programs to reduce scan time. We used Onco. Flash (Pixon method, SIEMENS) that is an image processing technique gated cardiac blood pool scan and going to evaluate its clinical usefullness. Materials and Method: We analyzed the 50 patients who were examined by gated blood pool scan in nuclear medicine department of Asan Mediacal Center from June $20^{th}$ 2008 to August $14^{th}$ 2008. We acquired the Full-time (6000 Kcounts) and Half-time (3000 Kcounts) LAO image in same position. And we acquired LVEF values ten times from Full-time, Half-time images acquired by the image processing technique and analyzed its mean and standard deviation values. To estimate LVEF in same conditions, we set automatic location of the LV ROI and background ROI based on same X and Y-axis. Also we performed blinding tests to physician. Results: After making a quantitative analysis of the 50 patients EF values, each mean${\pm}$standard deviation is shown at Full-time image $68.12{\pm}7.84%$, Half- time (acquired by imaging processing technique) $68.49{\pm}8.73%$. In the 95% confidence limit, there was no statistically significant difference (p>0.05). After blinding test with a physician for making a qualitative analysis, there was no difference between Full-time image and Half-time image acquired by the image processing technique for observing LV myocardial wall motion. Conclusion: Gated cardiac blood pool scan has been reported its relatively exact EF measured results than ultrasound or CT. But gated cardiac blood pool scan takes relatively longer time than other exams and now it needs to improve time competitive power. If we adapt Half-time technique to gated cardiac blood pool scintigraphy based on this study, we expect to reduce possible artifacts and improve accessibility as well as flexibility to exam. Also we expect patient's satisfaction.