• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.06a
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• pp.112-113
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• 2019

유무선 정보통신환경에 맞춰 제한된 비트율로 압축된 CCTV 영상의 화질은 좋지 않을 수 있다. 본 논문은 제한된 비트율로 압축된 영상내 관심영역의 화질개선을 위해, 영상압축을 수행 하기 전의 카메라 센서로 획득한 영상에 전처리를 수행하는 방법을 제안한다. 제안하는 알고리즘은 관심영역 및 비관심영역에 차등적 필터를 적용하여 화소 별 공간적 상관도를 향상시킨다. 제안된 방법을 사용한 결과 관심영역에서의 텍스처 손실을 최소화 할 수 있었으며 전처리 과정을 적용하지 않은 영상과 비교하여 객관적 화질이 향상됨을 확인할 수 있다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.679-686
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• 2014

Recently, users can get countless images and videos by network. So, the compression technology of image and video is researched more and more. However, the situation which is the interested range of the image is occurred. For instance, since the region of face is more important than background, the image compression technology bases on the region of interest (ROI) is necessary, in the ATM environment. In this research, given the human visual system, which are not sensitive to illumination variations at very dark and light regions of image, we calculate the standard deviation of block and use this value to define the ROI. In encoding process, the relatively high quality can be obtained at the ROI and the relatively low quality can be obtained at the non ROI. In proposed scheme, the feature which is the encoding process according to subjectively image quality can be demonstrated. Finally, this proposed scheme is applied to JPEG standard. The experimental results demonstrate that proposed scheme can achieve better image quality at the high compression ratio.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5860-5866
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• 2012

BOLD technique in functional MRI has to apply multiple stimulations. However as the stimulation time increases failure rates rise. In this study we are proposing proper number of stimulations through our experiments. Ten normal people underwent functional MRI hand motor sanning and the paradigms were designed from first to seventh stimulation. Under Philips Intera Achieva 3.0T MR system and Invivo cop's Eloquence equipment, activation periods and rest periods were repeated ten times each, using BOLD EPI technique. Primary hand motor area stimulation and number of clusters, activation rates and number of activated clusters in and outside the region of interest were compared to each other. Number of clusters in region of interest was lower than others at second stimulation and became static from third stimulation. The stimulated ratios were elevated as the number of stimulations were increased but it was not proportional. Number of clusters outside the ROI became static from the third stimulation and started increasing from sixth stimulation. As results, given the activation ratios of ROI and out side the ROI, three times stimulation was the most appropriate because it does not affect accuracy, also decreasing the fatigue of patients by with the decreased scanning time.

• Journal of Broadcast Engineering
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• v.17 no.4
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• pp.670-675
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• 2012

If the region of interest (ROI) is set within the picture of image and video and the high quality is provided in ROI compared to Non ROI, then overall subjective picture quality can be increased. ROI extracted by the color camera only increases the calculation complexity and reduces the extraction accuracy. In this paper, we use depth camera to set the ROI and calculate the object distance from camera, then propose a method that the different picture quality is controlled by depending on the distance of an object. That is, we apply a high quantization step size to the far object, but relatively a low quantization step size to the close object, so better picture quality can be provided. Simulation results show that applying the differential quantization step size to the distance of objects by the proposed method can improve the subjective picture quality.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.749-752
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• 2004

CT 영상에서 폐암 추출을 위한 컴퓨터지원진단시스템(CAD)에서 전처리 시스템은 매우 중요한 역할을 담당한다. 본 논문에서는 CT 영상에서 폐암 추출을 위한 전처리 기법을 소개한다. CT 영상에서 폐 영역 추출 과정에서 가장 먼저 수행되는 이진화를 위해 k-means 클러스터링 알고리즘을 이용하고, 비관심 영역 제거 방법으로 연결요소를 분석하고, 이진화 과정에서 발생한 폐 외곽 분실을 재구성하기 위해 Rolling Ball 알고리즘을 수행한다. 또한 분할된 폐 영역에서 폐암 후보자를 선출하기 위해 분할과정에서 수행하였던 이진화 방법을 폐 영역에 다시 한번 적용하고 잡음제거를 위해 모폴러지 기법을 사용한 전처리 기법을 제안한다.

• Journal of Korea Multimedia Society
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• v.14 no.9
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• pp.1117-1124
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• 2011

This paper proposes a plate number extraction method which uses the information of both the colors and the arrangement of numbers in a vehicle image with complex background. In a number plate, color of the numbers is usually black or white, and numbers are arranged in a row. At first, a raw image is partitioned into the plate number candidate regions and non-interest region. The number candidate regions are thresholded in mean binarization. After eliminating the illegal candidate regions using the aspect ratio of the plate number, the plate number region is finally extracted by using the arrangement information among the numbers. To evaluate the proposed mothed, 292 images are taken in various places and at different times. The experimental results show that the rate of the proposed number regions extraction is about 89.8%, 95.5% for the plate of green and white backgrounds, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.525-531
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• 2019

Efforts to utilize human gestures to effectively implement a more natural and interactive interface between humans and computers have been ongoing in recent years. In this paper, we propose a new algorithm that accepts consecutive three-dimensional (3D) depth images, defines a hand model, and robustly extracts the human hand region based on six palm joints and 15 finger joints. Then, the 3D depth images are adaptively binarized to exclude non-interest areas, such as the background, and accurately extracts only the hand of the person, which is the area of interest. Experimental results show that the presented algorithm detects only the human hand region 2.4% more accurately than the existing method. The hand region extraction algorithm proposed in this paper is expected to be useful in various practical applications related to computer vision and image processing, such as gesture recognition, virtual reality implementation, 3D motion games, and sign recognition.

• Journal of The Korean Dental Society of Anesthesiology
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• v.4 no.2 s.7
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• pp.96-99
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• 2004

구강저를 통한 기관내 삽관은 1986년 Altemir에 의해 처음 소개된 바 있는데 그 후 1993년 Hoenig와 Braun 및 같은 해 Stoll 등에 의해서나, 또는 1996년 Prochno 등에 의해 계속 변형된 방법으로 문헌에서 기술되어 왔다. 이 방법은 치과 영역 특히 구강악안면외과의 외상수술시 이상적인 교합을 얻기 위해 임시 상하악간 고정(intermaxillary fixation)을 할 수 있고 중안모 골절(midface fracture)의 회복을 위한 비관 삽관의 불편함을 피할 수 있는 유리한 점이 있으며, 또한, 정복 및 고정술이 필요한 비골 골절(nasal bone fracture)에서나 두개기저골 골절(skull base fracture)에서 여러 감염 등 합병증을 피하기 위해 추천될 수 있다. 또한, 목 부위에 비심미적인 반흔을 만들게 되며 여러 합병증을 초래할 수 있는 기관절개술(tracheostomy)보다 유용할 수 있다. 본 증례보고에서는 교통사고로 두개기저부 골절을 동반한 심한 중안모 골절 환자에서 적용시킨 경우를 알아보고, 아울러 이러한 악하부 삽관의 장, 단점 및 시술 과정 등에 대해 고찰해보고자 한다.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.3
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• pp.378-385
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• 2018

Mandibular fractures occur with high incidence among various fractures in maxillofacial region in children. Jaw fractures in children should be approached differently than in adults because bone growth continues throughout childhood. As far as displacement of the fragment is not severe, or if it is condyle that is fractured, closed reduction and additional intermaxillary fixation can be considered. Functional exercise is also required to prevent ankylosis of temporomandibular joint. Several complications, particularly malocclusion and facial asymmetry due to growth disturbances, can occur after condylar fractures. If growth disturbances take place after mandibular fractures, catch-up growth may occur in some patients, thus, periodic observation is necessary. In case of persistent growth disturbances, functional devices may be used to prevent severe facial asymmetry. This case report describes the long-term follow-up of two patients with facial asymmetry after mandibular fracture.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.2
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• pp.311-326
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• 2018

This paper has experimented using News sample video with QCIF ($176{\times}144$) resolution in JM v10.2 code of H.264/AVC-MPEG. The region of interest (ROI) to be encrypted occurred the drift by unnecessarily referring to each frame continuously in accordance with the characteristics of the motion prediction and compensation of the H.264 standard. In order to mitigate the drift, the latest related research method of re-inserting encrypted I-picture into a certain period leads to an increase in the amount of additional computation that becomes the factor increasing the bit-rate overhead of the entire video. Therefore, the reference search range of the block and the frame in the ROI to be encrypted is restricted in the motion prediction and compensation for each frame, and the reference search range in the non-ROI not to be encrypted is not restricted to maintain the normal encoding efficiency. In this way, after encoding the video with restricted reference search range, this article proposes a method of RC4 bit-stream encryption for the ROI such as the face to be able to identify in order to protect personal information in the video. Also, it is compared and analyzed the experimental results after implementing the unencrypted original video, the latest related research method, and the proposed method in the condition of the same environment. In contrast to the latest related research method, the bit-rate overhead of the proposed method is 2.35% higher than that of the original video and 14.93% lower than that of the latest related method, while mitigating temporal drift through the proposed method. These improved results have verified by experiments of this study.