• Annual Conference of KIPS
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• 2018.10a
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• pp.606-608
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• 2018

최근 CCTV나 블랙박스 등 멀티미디어 데이터를 생성해내는 장치의 사용이 늘어나고 있다. 이러한 대용량 멀티미디어 데이터가 증가함에 따라 사용자가 동영상과 같은 멀티미디어 데이터 내의 객체를 식별하기 위해서는 많은 시간을 할애하여 매뉴얼하게 일일이 찾아야 하는 한계점이 있다. 본 논문에서는 사용자가 동영상 및 이미지에서와 같은 멀티미디어 데이터에서 객체를 자동으로 식별할 수 있 수 있는 딥러닝 기반의 객체 식별 및 검색 모델을 제안한다. 제안하는 객체 식별 검색은 이미지 검색과 동영상 검색을 지원한다. 이미지 검색에서는 이미지에 존재하는 동일한 객체를 검색 대상 이미지들에서 객체를 식별하고, 이미지에 존재하는 객체를 검색하여 결과로 반환한다. 또한 동영상 검색에서는 동영상에서 검색하고자 하는 객체를 식별하고 객체가 출현하는 시간을 전처리과정을 통해 기록하며, 검색하고자 하는 동영상 내에 존재하는 객체의 검색이 가능하다. 따라서 사용자가 동영상에서 객체의 검색 시 키워드 검색이 가능하여 동영상을 모두 재생하서 객체를 식별해야 하는 번거로움을 해결할 수 있다.

• Journal of the Korea Society of Computer and Information
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• v.19 no.9
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• pp.11-19
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• 2014

In this paper, we propose a real-time video transcoding scheme for N-Screen service based on cloud computing. This scheme creates an intro-block and several playback blocks by splitting the original video. And there is the first service request, after transmitting the intro-block, transmits the playback blocks that converting the blocks on real-time. In order to completing trans-coding within playback time of each block, we split and allocate the block to node according to performance of each node. Also, in order to provide real-time video playback service, the previous scheme convert original video into all format and resolution. However we show that the proposed scheme can reduce storage usage by converting original video into format with proper resolution suitable to device and platform of client. Through simulation, we show that it is more effective to real-time video playback for N-screen service than the previous method. We also show that the proposed scheme uses less storage usage than previous method.

• Journal of Broadcast Engineering
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• v.7 no.2
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• pp.114-125
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• 2002

Although there have been a lot of researches on a video abstraction algorithm, the video abstraction tool is necessary to correctly pick up some important shots in a video because the important shots might vary on the person's subjectivity. This paper proposes a video abstraction and search system for making a video abstraction automatically or manually. Proposed system has two main components, server and client. The server generates the Metadata and makes a video abstraction file. The description for video abstraction file is based on MPEG-7. Since proposed system has a function to manually correct the results of each step, the author could produce a good video abstraction easily and efficiently. The proposed system could be used to build a digital video library.

• Journal of Broadcast Engineering
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• v.9 no.3
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• pp.236-245
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• 2004

A multiview sequence CODEC with view scaiability is proposed in this paper. We define a GGOP (Group of GOP) structure as a basic coding unit to efficiently code multiview sequences. 7he proposed CODEC provides flexible GGOP structures based on the number of views and baseline distances among cameras. Multiview sequences encode consists of disparity estimation/compensation, motion estimation/compensation, residual coding and rate control and generates multiview sequence bitstream. The main bitstream is the same as an MPEG-2 mono-sequence bitstream for MPEG-2 compatibility. The auxiliary bitstream contains information concerning the remaining multiview sequences except for the reference sequences. The proposed CODEC with view scalability provides that a number of view flints are selectively determined at the receiver according to the type of display modes. The proposed multiview sequence CODEC is tested with several multiview sequences to determine its flexibility. compatibility with MPEG-2 and view scaiability. In addition, we subjectively confirm that the decoded bitstreams with view scaiability can be Properly displayed by several types of display modes. including 3D monitors.

• Journal of Internet Computing and Services
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• v.3 no.5
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• pp.51-62
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• 2002

The development of computer technology and the advancement of the technology of information and communications spread the technology of multimedia and increased the use of multimedia data with large capacity, Users can grasp the overall video data and they are able to play wanted video back. To grasp the overall video data it is necessary to offer the list of summarized video data information, In order to search video efficiently on index process of video data is essential and it is also indispensable skill, Therefore, this thesis suggested the effective method about the cut detection of frames which will become a basis of an index based on contents of video image data. This suggested method was detected as the unchanging pixel color intelligence value, classified into diagonal direction. Pixel value of color detected in each frame of video data is stored as A(i, j) matrix-i is the number of frames. j is an image height of frame. By using the stored pixel value as the method of sum of squared difference of color two frames I calculated a specified value difference between frames and detected cut quickly and exactly in case it is bigger than threshold value set in advance, To carry out on experiment on the cut detection of frames comprehensively, I experimented on many kinds of video. analyzing and comparing efficiency of the cut detection system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.10a
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• pp.231-237
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• 1994

컴퓨터의 눈부신 발달에 힙입어 실험 또는 해석적 방법으로 일반 구조물이나 기계구조물의 진동특성을 손쉽고 정확하게 파악하는 것이 가능하게 되었다. 그런데 최근의 산업현장은 지금까지의 정확한 구조해석에만 그치지 않고 이를 바탕으로 강도 개선, 재료 절감을 통한 원가절감, 중량 최소화 문제등의 차원에서 동적인 특성의 변경을 요구하고 있다. 이러한 문제는 그 중요성에도 불구하고 여전히 설계자의 경험이나 시행착오에 의존하고 있는 실정이다. 본 연구에서는 구조물 결합부분에 주목하여 동특성의 변경 문제를 해석하고자 하였다. 즉 거의 모든 구조물이 결합부를 가지고 있는데 결합부 특성을 정확히 파악할 수 없기 때문에 리벳이나 보울트나 어떤 특수한 형태 결합부가 구조물의 특성에 주는 영향을 예측하기 어렵다. 이러한 결합부이 특성을 알아내고 구조물 동특성 변경 및 개선안을 제시하는 최적설계를 위해 감도해석기법은 아주 유효하게 쓰일 수 있다. 한편 구조물의 대형화, 복잡화는 구조물 동특성 해석에 더욱 많은 계산시간과 용량이 큰 전자계산기를 필요로 하게 되었으며, 분계의 결합부위가 변경되거나 결합형태가 변했을 때 전계의 동특성을 다시 해석할 필요없이 분계만의 정보로부터 전계의 동특성을 알아낼 필요가 생겼다. 이러한 의미에서 구조물의 분계로부터 전계의 동특성을 해석을 위한 부분구조합성법이 대두되게 되었다. 본 연구에서는 이러한 감도해석과 부분구조합성법의 공통된 문제를 일치화하고자 하였다. 즉 감도해석기법을 이용하여 필요한 구조물의 동특성에 부합하는 결합부의 최적한 설계변수를 규명하였고 이렇게 구해진 결합부의 설계변수와 분계의 정보를 알고리즘이 비교적 간단하고 오차가 적은 축소임피던스 합성법에 적용하여 전계의 동특성을 해석함으로써 감도해석기법과 축소임피던스 합성법의 통합적용이 최적설계와 이에 따른 동특성 해석에 효과적인 방법임을 보이고자 하였다. 대상구조물은 구조물 결합의 기본적인 형태인 T형을 선택하였다. T형 구조물은 분계 A(16개의 사각요소)와 분계 B(8개의 사각요소)로 이루어져 있으며 두개의 스프링으로 결합되어 있다. 설계변수는 강성에 국한하였으며 결합부의 결합형태는 탄성결합과 강결합으로 하였다. 감도해석과 축소임피던스 합성법에 의해 구해진 고유진동수와 FRF를 상용 유한 요소 해석 패키지인 MSC/NASTRAN을 통하여 검증하여 이 연구의 타당성을 검토하였다.

• Journal of Internet Computing and Services
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• v.7 no.3
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• pp.133-142
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• 2006

The purpose of the multiple key agreement protocol is to get efficiency in computational and communicational aspects compared to multiple executions of single key agreement protocol. However ID based tripartite multiple key agreement protocols have been proposed, it is reported that they can not resist unknown key-share attack or impersonation attack. How to design a secure and efficient ID-based authenticated tripartite multiple key agreement scheme to prevent all kinds of attacks remains an open problem. This paper proposes a multiple key agreement scheme combing the existing single key agreement protocol with a key derivation function. The proposed scheme can not only increase computational efficiency compared to the existing multiple key agreement protocol, but can ensure security of the proposed schemes by using a security proofed single key agreement protocol and key derivation function.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.3
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• pp.103-110
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• 2008

This paper proposes an effective keyword extraction method for the Web videos. The proposed method classifies the Web video pages in one of 4 types. As such, we analyzed the structure of the Web pages based on the number of videos and the layout of the Web pages. And then we applied the keyword extraction algorithm fit to each page type. The experiment with 1,087 Web pages that have total 2,462 videos showed that the recall of the proposed extraction method is 18% higher than ImagerRover[2]. So, the proposed method could be used to build a powerful video search system for WWW.

• Journal of KIISE:Software and Applications
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• v.30 no.7_8
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• pp.599-609
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• 2003

Video abstraction is a process to pick up some important shots on a video, while the important shots might vary on the persons subjectivity. Previous works on video abstraction use only one low level feature to choose an important shot. This thesis proposes an abstraction scheme that selects a set of shots which simultaneously satisfies the desired features(or objective functions) of a good abstraction. Since the complexity of the computation to find a set of shots which maximizes the sum of object function values is $0({2^n})$, the proposed .scheme uses a simulated annealing based searching method to find the suboptimal value within a short period of time. Upon the experimental results on various videos, we could argue that the proposed abstraction scheme could produce a reasonable video abstraction. The proposed abstraction scheme used to build a digital video library.

• Journal of Broadcast Engineering
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• v.15 no.3
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• pp.368-379
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• 2010

As high-definition video is broadly used in various system such as broadcast system and digital camcorder the proper method in order to improve the quality of high-definition video is needed. In this paper, we propose an efficient method to improve color and contrast of high-definition video. In order to apply the image enhancement method to high-definition video, scale-down video of high-definition video is used and the parameter for image enhancement method is computed from small size video. To enhance the color of high-definition video, we apply color constancy method. First, we separate the video into several scenes by cut detection method. Then, we apply color constancy to each scene with same parameter. To improve the contrast of high-definition video, we use union of original image and histogram equalized image, and weight is calculated based on sorting of histogram bins. Finally, the performance of proposed method is demonstrated in experiment section.