• Journal of the Korean Institute of Intelligent Systems
• /
• v.17 no.4
• /
• pp.443-450
• /
• 2007

In this paper, we propose a novel threshold selection method based on statistical information on gray-levels of given images and interval-valued fuzzy sets. In the proposed threshold selection method, the interval-valued fuzzy set is used to represent more definitely the relationship between a pixel and its belonging region, that is, the object and the background. Also the statistical information on gray-level is used to determine the rules and partitions of interval-valued fuzzy sets. To show the validity of the proposed method, we compared the performance of the proposed with those of conventional methods such as Otsu's method, Huang and Wang's method applied to 5 test images with various types of histograms.

• Archives of design research
• /
• v.12 no.1
• /
• pp.51-60
• /
• 1999

Since the appearance of moving images, the expansion of mass media such as 1V or VCR has made the pace and range of spreading information to people faster and widely popular. Recendy, the development of digital image technique has resulted in solving the problem -great defect- of the display quality of analogue system; special effects by means of computer graphics have risen to a higher quality level; showed the new direction of digital image; and popular wi1h people all c:Ner the world. This paper reestablishes the notion of image up to now, and analyses the technical differences between analogue system and digital system on the basis of the SpecifIC property and skill of digital image editing; it also studies the special effects which can be applied to the image editing software. Moreover, in researdting 1V advertising, the special effects by digital system in use in 1his country today complies with the statistics in their own field. The special effects in 1V advertising is performed at a higher standard by a professional production. Accordingly, with the help of technology of digital moving image, the special effects are expected to continue developing into a level of high quality

• Journal of Internet Computing and Services
• /
• v.11 no.1
• /
• pp.85-102
• /
• 2010

In this paper, we propose a novel method of analyzing video and representing the relationship among characters based on their contexts in the video sequences, namely Character-Net. As a huge amount of video contents is generated even in a single day, the searching and summarizing technologies of the contents have also been issued. Thereby, a number of researches have been proposed related to extracting semantic information of video or scenes. Generally stories of video, such as TV serial or commercial movies, are made progress with characters. Accordingly, the relationship between the characters and their contexts should be identified to summarize video. To deal with these issues, we propose Character-Net supporting the extraction of major characters in video. We first identify characters appeared in a group of video shots and subsequently extract the speaker and listeners in the shots. Finally, the characters are represented by a form of a network with graphs presenting the relationship among them. We present empirical experiments to demonstrate Character-Net and evaluate performance of extracting major characters.

• Geophysics and Geophysical Exploration
• /
• v.19 no.3
• /
• pp.111-120
• /
• 2016

In order to enhance the connectivity of fracture network as fluid path in enhanced/engineered geothermal system (EGS), the exact locating of hydraulic fractured zone is very important. Hydraulic fractures can be tracked by locating of microseismic events which are occurred during hydraulic fracture stimulation at each stage. However, since the subsurface velocity is changed due to hydraulic fracturing at each stage, in order to find out the exact location of microseismic events, we have to consider the velocity change due to hydraulic fracturing at previous stage when we perform the mapping of microseimic events at the next stage. In this study, we have modified 3D locating algorithm of microseismic data which was developed by Kim et al. (2015) and have developed 3D velocity update algorithm using occurred microseismic data. Eikonal equation which can efficiently calculate traveltime for complex velocity model at anywhere without shadow zone is used as forward engine in our inversion. Computational cost is dramatically reduced by using Fresnel volume approach to construct Jacobian matrix in velocity inversion. Through the numerical test which simulates the geothermal survey geometry, we demonstrated that the initial velocity model was updated by using microseismic data. In addition, we confirmed that relocation results of microseismic events by using updated velocity model became closer to true locations.

• Journal of Korea Entertainment Industry Association
• /
• v.13 no.5
• /
• pp.119-126
• /
• 2019

Watching movies is common on a big screen like a theater or on a big-screen TV. nowadays, small platform such as mobile devices is increasing rapidly for watch a movie. These changes are deeply related to the advent of Internet-based video streaming services such as OTT. OTT's development has provided in free video viewing system without using the set-top box is free from the limitations of time and space. Leading the market is Netflix[1], which started its business with Internet-based DVD rental service. Netflix, which is growing in tandem with the mobile market, had 193.26[2] million members as of the end of 2018. Other OTT participating companies include content-based Pooq, TVing, platform-based Olleh TV Mobile, Oksusu and LTE video portal. The size of such new growth projects has grown gradually, with 25.4 percent of all smartphone users currently watching video content with small mobile devices. Therefore, de-largeization, it is thought that visual language is needed for viewing small mobile devices that are capable of OTT services. To this end, this paper will identify the problem in viewing popular video content with small mobile devices and Survey and study its impact on viewers using the questionnaire.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.11
• /
• pp.67-76
• /
• 2011

This paper describes the development of interactive visualization techniques and a program that allow us to visualize the structure of the volume data and interactively select and visualize the isosurface components using contour tree. The main characteristic of this technique is to provide an algorithm that draws the contour tree in 2D plane in a way that users easily understand the tree, and to provide an algorithm that can efficiently extract an isosurface component utilizing GPU's parallel architecture. The main characteristic of the program we developed through implementing the algorithms is to provide us with an interactive user interface based on the contour tree for extracting an isosurface component and visualization that integrates with previous isosurface and volume rendering techniques. To show the excelland vof our methods, we applied 3D biomedical volume data to our algorithms. The results show that we could interactively select the isosurface components that represent a polypeptide chain, a ventricle and a femur respectively using the user interface based on our contour tree layout method, and extract the isosurface components with 3x-4x higher speed compared to previous methods.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2003.03a
• /
• pp.144-144
• /
• 2003

니켈계 내열합금의 성형은 수백 $^{\circ}C$에 이르는 고온에서 이루어지기 때문에 열간성형 과정에서 소재 내부의 미세조직 변화에 대한 이해는 부품의 특성 제어 측면에서 매우 중요하다. 특히 열간 동적 재결정에 의해 발생되는 결정립 구조의 변화를 적절히 조절함으로써 부품의 특성을 극대화 할 수 있다. 본 연구에서는 Ni-Fe계 초내열합금에 대한 고온 압축실험과 압축시편에 대한 EBSD 분석을 통해 열간 변형 과정에서 발생하는 소재 내부의 동적인 결정립 구조의 변화를 정량적으로 분석하고자 하였다. 고온 압축시험은 101$0^{\circ}C$, 1066$^{\circ}C$의 온도 조건과 0.5s-1, 0.005s-1의 변형율 속도 조건에서 최대 진변형율 0.7까지 수행하였으며 진변형율에 따른 결정립 조직 변화를 관찰하기 위해 진변형 율에도 변화를 주어 실험을 수행하였다. 이들 고온 압축시편은 응력방향에 평행한 면에 대한 미세조직 관찰을 통해 재결정립 크기, 분율 및 결정립계의 특성 변화에 대한 정량적 연구를 수행하였다.

• Proceedings of the IEEK Conference
• /
• 2003.11a
• /
• pp.393-396
• /
• 2003

This paper proposes a method to speed up the document image binarization using a water flow model. The proposed method extracts the region of interest (ROI) around characters from a document image and restricts pouring water onto a 3-dimensional terrain surface of an image only within the ROI. The amount of water to be filled into a local valley is determined automatically depending on its depth and slope. Then, the proposed method accumulates weighted water not only on the locally lowest position but also on its neighbors. Finally, the depth of each pond is adaptively thresholded for robust character segmentation. Experimental results on real document images shows that the proposed method has attained good binarization performance as well as remarkably reduced processing time compared with that of the existing method based on a water flow model.

• Annual Conference of KIPS
• /
• 2004.05a
• /
• pp.1043-1046
• /
• 2004

본 논문에서는 MPEG-4 스트림의 디지털 저작권 관리(DRM)를 위한 암호화 방법을 제안한다. MPEG-4는 멀티미디어 스트리밍을 위한 표준이며 MPEG-4 파일 포맷에 따라 저장된다. 인가된 사용자들만 접근이 가능하도록 MPEG-4 파일 포맷으로부터 추출된 I-VOP, P-VOP의 매크로 블록(MB)들과 모션 벡터(MV)들을 암호화 하는 3가지 방법을 설계하였고, MPEG-4 데이터의 암호화에는 DES(Data Encryption Standard)를 사용하였다. 이러한 암호화 방법을 기반으로 MPEG-4 데이터 스트리밍을 위한 인터넷 방송 서비스용 DRM 솔루션을 구현하고, 최적의 암호화 방법을 선택하기 위해 복호화 속도 및 영상의 품질을 비교하였다.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.48 no.3
• /
• pp.21-29
• /
• 2011

This paper presents a method that estimates distance and velocity of an object with reliability regardless of maneuver status of the target in stereo vision system. A stereo vision system can calculate a distance with disparity from left and right images. However, the distance estimation error may occur due to quantization error of image pixel. A sub-pixel interpolation method minimizes the quantization error and estimates accurate disparity with real value. Extended Kalman filter (EKF) was used to minimize the error covariance and estimate the object's velocity. However, divergence problem occurs due to model uncertainty when a target maneuvers highly, which makes the estimation error increase. In this paper, we propose a virtual model extended Kalman filter (VMEKF) method that minimizes the processing time and provides reliable estimation ability regardless of maneuver status. Computer simulations and experimental results in real road environments demonstrate that the proposed method gives a reliable estimation performance and reduces processing time under various maneuver status while comparing other estimation filters.