• Aerospace Engineering and Technology
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• v.10 no.2
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• pp.29-36
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• 2011

The Science and Technology Satellite-3 (STSAT-3) is based on the KITSAT-1, 2, 3 and STSAT-1, 2 which were Korea micro-satellites for the mission of space and earth science. The objectives of the STSAT-3 are to support earth and space sciences in parallel with the demonstration of spacecraft technology. The STSAT-3 carries an infrared (IR) camera for space & earth observation and an imaging spectrometer for earth observation. The IR payload instrument of the STSAT-3, Multi-purpose Infrared Imaging System (MIRIS), will observe the Galactic plane and North/South Ecliptic poles to research the origin of universe. The secondary payload instrument, Compact Imaging Spectrometer (COMIS), images the Earth's surface. The data acquired from COMIS are expected to be used for various application fields such as monitoring of disaster management, water quality studies, and farmland assessment. In this paper we present the operations concept of STSAT-3 which will be launched into a sun-synchronous orbit at a nominal altitude of 600km in late 2012.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.275-279
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• 2023

Granular cell tumors (GCTs) are rare benign soft tissue tumors that can occur throughout the body, particularly the head and neck; only 5%-8% of GCTs occur in the breast. We report a case of a GCT of the axillary accessory breast, which is a rare location of this tumor. A 50-year-old woman had a 2-month history of a palpable mass in the left axilla. Physical examination, as well as mammographic and ultrasonographic findings suggested a breast malignancy. Histopathological examination showed a benign GCT, and wide local excision was performed. The patient has remained disease-free over 2 years postoperatively. Although most GCTs are benign, wide complete resection of the tumor and follow-up are required considering the possibility of recurrence. The radiologist should know the characteristics of GCTs as a differential diagnosis of breast and axillary lesions to prevent unnecessary treatment.

• Journal of Biomedical Engineering Research
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• v.23 no.5
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• pp.365-373
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• 2002

Accurate localization of target lesion is required to protect normal peripheral tissue and irradiate exactly to tumors in stereotactic radiosurgery(SRS). Digital angiography is one of the most effective diagnostic tools to detect and identify the target tumors. However, it shows pincushion distortion due to the characteristics of the image intensifier. We have implemented a simulation study for the correction of distortion using the geometric transformation. Phantom images were produced transformation. In conclusion, the geometric transformation could effectively be used for the pincushion distortion of image intensifier and there was no significant different between two methods indicating 2% correction error from the ideal image in all cases.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.1
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• pp.60-69
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• 2019

In this paper, we deal with forward-looking imaging, and focus on forward-looking synthetic inverse scattering imaging for a vehicle with curved motion. For image formation, time domain correlation(TDC) is used and a 2D image of the ground in front of the vehicle is generated. Because TDC is a technique that implements matched filtering for a space-variant system, it is robust to Gaussian additive noise of measurements. Furthermore, comparison and analysis between images from linear motion and curved motion show that the resolution of the image is improved; however, the entropy of the image is increased owing to curved motion.

• Journal of KIISE:Software and Applications
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• v.37 no.3
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• pp.170-176
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• 2010

Prediction is an important step in high-performance lossless data compression. In this paper, we propose a novel lossless image coding algorithm to increase prediction accuracy which can display low-resolution images quickly with a multi-resolution image technique. At each resolution, we use pixels of the previous resolution image to estimate current pixel values. For each pixel, we determine its estimated value by considering horizontal, vertical, diagonal edge information and average, weighted-average information obtained from its neighborhood pixels. In the experiment, we show that our method obtains better prediction than JPEG-LS or HINT.

• The Journal of Korean Association of Computer Education
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• v.14 no.1
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• pp.111-122
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• 2011

In this paper, we develop a system that can add additional information to video for educational purposes by utilizing various Open APIs. Teachers can use the system to reconstruct general videos for educational purposes. Especially, teachers can use various Open APIs easily without programming by simply typing keywords. In addition, the system manages the information about keywords so that it can provide learning contents that are appropriate for the students. Using the proposed system, students can easily understand the contents of the video and extend the knowledge since the information about keywords are adaptively provided.

• The Journal of Engineering Research
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• v.2 no.1
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• pp.49-56
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• 1997

In emission computed tomography, statistical reconstruction methods in the context of a Bayesian framework have been a topic of interest over the last decade. This was mainly due to the fact that Bayesian approaches can incorporate a priori information into the reconstruction algorithm. Although these approaches can exhibit good performance, their applications to the clinic is hindered mainly by their high computational cost. On the other hand, the speed and simplicity of the filtered backprojection (FBP) algorithm have led to its widespread use in most clinical applications. In this work, we use spline models, which have been quite useful in Bayesian reconstruction, as regularizers for high-frequency apodization in FBP algorithm and show that the effects of using spline models as priors in Bayesian reconstruction can also be achieved in FBP reconstruction.

• 대한핵의학회:학술대회논문집
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• 2004.11a
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• pp.411.2-411.2
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• 2004

• The Journal of Information Technology
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• v.7 no.4
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• pp.1-8
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• 2004

The depth information of 3D image lost by projecting 3D-object to 2D-screen for earning image. If depth information is restored and is used to recognize 3D-object, we can make the more effective recognition system. We often use shape from stereo algorithm in order to restore this information. In this paper, we suggest 3-D object recognition system in which the 3-D Hough transform domain is employed to represent the 3-D objects. In this system, we use the moving vector of object to reduce matching time and In second matching step, the unknown input image is compared with the reference images, which is made with octree codes. Octree codes are used in volume-based representation of a three dimensional object. The result of simulation show that the proposed 3-D object recognition system provides satisfactory performance.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.11a
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• pp.233-235
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• 2010

영상 압축은 멀티미디어 실시간 전송에 있어서 핵심적인 기술이다. 동영상 압축 기술 중 움직임 예측 부분은 가장 계산량이 많고 가장 복잡한 부분으로 실시간 전송을 위해서는 고속 알고리즘이 필요한 부분이다. 본 논문은 기존의 움직임 예측 알고리즘의 하나인 이진 블록 정합 움직임 예측 알고리즘 중 2bit 변환을 개선하여 더욱 빠른 알고리즘을 제안한다. 기존의 2bit 변환 알고리즘은 현재 프레임과 이전 프레임의 블록에 윈도우를 씌어 각 프레임의 윈도우에서 구한 평균과 표준편차를 가지고 각각 2bit 변환을 하였다. 그러나 본 논문은 현재 프레임과 이전 프레임의 블록에 윈도우를 씌우고 현재 프레임의 윈도우에서 구한 평균과 표준편차를 이전 프레임에 적용을 시켜 같은 평균과 표준편차를 이용하여 기존의 알고리즘을 개선한다. 제안하는 알고리즘은 계산량의 감소와 동시에 화질을 유지시킨다.