• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2000.11b
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• pp.155-159
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• 2000

본 논문에서는 MPEG-7 질감 기술자에 기반한 영상의 내용기반 검색 시스템에서 유사도 검색 알고리즘에 대하여 다룬다. 제안하는 알고리즘은 영상의 회전에 대하여 변화하지 않는 특성을 지닌다. 실제적으로 영상이나 비디오에서 질감 정보를 이용하여 검색을 수행하고자 하는 영상에 대하여 회전 불변 알고리즘은 반드시 필요하다. 본 논문에서 제한된 알고리즘을 이용하여 질감 영상회전 불변 유사도 측정에 따른 검색을 수행하였다. 본 논문의 실험은 회전 불변 성능을 측정하는 MPEG-7 질감 데이터베이스에서 검색 율을 측정하였다. 실험결과 본 영상 회전 불변 질감 기술자 표현 방법은 우수한 검색 성능과 빠른 특징 추출 능력을 보였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.381-384
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• 2013

본 논문에서는 허밍기반 음원 검색 시스템을 위한 오디오 특징 시퀀스 데이터 색인 기법을 제안한다. 우선 Query-by-Singing/Humming (QbSH) 시스템의 특징 데이터베이스를 생성하기 위하여 MP3 와 같은 다성음원에서 주요 멜로디를 추출하여 시퀀스데이터를 생성하고, 고속 검색을 지원하기 위한 시퀀스데이터를 색인화한다. 본 논문에서는 최소 Dynamic Time Warping (DTW) 거리 기법, 시퀀스 추상화 기법, 상한 값 기반 DTW 기법과 같이 세 가지의 시퀀스 데이터의 색인화 기술을 제시하고 각각에 대한 문제점을 파악하고, 성능을 평가한다. 이를 통하여 향상된 검색 시간과 검색 정확도를 얻을 수 있다.

• Journal of Information Technology Applications and Management
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• v.12 no.1
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• pp.125-140
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• 2005

Nowadays, we have many embedded systems which store and process multimedia data. For multimedia systems using hard disks as storage media such as DVR, existing file systems are not the right choice to store multimedia data in terms of cost. performance and reliability. In this study we designed a reliable file system with very high performance for embedded multimedia applications. The proposed file system runs with quite simple disk layout to reduce time to initialize and to recover after power failures, uses a large data block to speed up the sequential accesses, incorporates a time-based indexing scheme to improve the time-based random accesses and boosts reliability by backing up the important meta data on a small NVRAM. We implemented the file system on a Linux-based DVR and verified the performance by comparing with existing file systems.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2005.11a
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• pp.239-242
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• 2005

본 논문은 디지털 방송에서 다양한 부가 정보 제공 및 관련 기기의 기능을 효과적으로 활용하기 위한 연구로서, 방송 시스템에서의 방송이나 편집 등을 고려하여 색인 정보를 재사용하는 알고리즘에 관한 것이다. 이를 위해 본 논문에서는 비주얼 리듬을 이용한 원본 영상과 목표 영상의 매칭을 제안하며, 비주얼 리듬의 히스토그램을 특징 벡터로 사용하여 유사도를 계산한다. 검색 시 목표 영상에 대해 우선 검색 구간을 설정하여 검색 시간을 줄이고자 하였으며, 실제 이 알고리즘을 적용한 결과 약97%의 정확도의 매칭 결과를 보였다. 또한 결과를 시각적으로 쉽게 알 수 있었기에 오류를 수정하는데 수월하였다. 이를 통해 기존의 색인화 정보를 목표 영상의 복호화작업 없이 쉽게 재사용 할 수 있어, 불필요한 비용의 증가를 방지하는 효과를 기대할 수 있다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2003.11a
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• pp.227-230
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• 2003

최근 디지털 방송이 시작됨에 따라 방송 채널이 다변화하고 그 수도 많아지고 있다. 현재 방송되고 있는 디지털 당송에 지상파 방송과 케이블 TV의 그 방송까지 고려한다면 시청자가 접합 수 있는 방송은 다양하다. 기업들은 주요 홍보 매체인 방송을 통해 자신들의 상품을 광고로 내보낸다. 또한 자신들의 광고에 대한 모니터링을 통해 광고가 계약한 시간, 횟수, 광고의 길이에 맞게 방영되는지 알고 식어 한다. 현재 이러한 모니터링은 사람에 의한 수작업으로 이루어지고 있으며, 여러 채널의 방송에 광고를 내보냈을 때에는 이러한 모니터링은 더욱 어려워진다. 본 논문에서는 디지털 방송뿐만 아니라 아날로그 방송에 대해서까지도, 현재 방송의 비주얼 리듬을 실시간으로 추출하고 이를 이용하여 장면 전환을 수행하고 특징 벡터를 추출해서 얻어진 정보들을 이용한 실시간 광고 검출 알고리즘을 제안한다.

• Journal of Information Management
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• v.31 no.4
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• pp.50-70
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• 2000

Since the contents of internet resources are beginning to include texts, images and sounds, different Web-based image search engines have been developed accordingly. It is a fact that these diversities of multimedia contents have made search process and retrieval of relevant information very difficult. The purpose of the study is to compare and evaluate its special features and performance of the existing image search engines in order to provide user help to select appropriate search engines. The study selected AV Photo Finder, Lycos MultiMedia, Amazing Picture Machine, Image Surfer, WebSeek, Ditto for comparison and evaluation because of their reputations of popularity among users of image search engines. The methodology of the study was to analyze previous related literature and establish criteria for the evaluation of image search engines. The study investigated characteristics, indexing methods, search capabilities, screen display and user interfaces of different search engines for the purpose of comparison of its performance. Finally, the study measured relative recall and precision ratios to evaluate their electiveness of retrieval under the experimental set up. Results of the comparative analysis in regard to its search performance are as follows. AV Photo Finder marked the highest rank among other image search engines. Ditto and WebSeek also showed comparatively high precision ratio. Lycos MultiMedia and Image Surfer follows after them. Amazing Picture Machine stowed the lowest in ranking.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.166-174
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• 2010

SSDs are one of the best media to support portable and desktop computers' storage devices. Their features include non-volatility, low power consumption, and fast access time for read operations, which are sufficient to present flash memories as major database storage components for desktop and server computers. However, we need to improve traditional index management schemes based on B-Tree due to the relatively slow characteristics of flash memory operations, as compared to RAM memory. In order to achieve this goal, we propose a new index management scheme based on a compressed hot-cold clustering called CHC-Tree. CHC-Tree-based index management improves index operation performance by dividing index nodes into hot or cold segments and compressing pointers and keys in the index nodes and clustering the hot or cold segments. The offset compression techniques using unused free area in cold index node lead to reduce the number of slow erase operations in index node insert/delete processes. Simulation results show that our scheme significantly reduces the write and erase operation overheads, improving the index search performance of B-Tree by up to 26 percent, and the index update performance by up to 23 percent.

• Archives of design research
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• v.13 no.3
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• pp.313-320
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• 2000

Currently, The new wave of information technology has enormously influenced every field. In the Held of design, it is time to strive possible efforts in order to accumulate the design-related knowledge by maintaining, managing and controlling design information in a systematic manner, getting out of the old stage of mere use of data itself. Due to remarkable progress in communication media and speed, and file compression technology, text-centric data has been shifting to multimedia data such as image and motion picture. So it is currently required that methologies be developed to effectively utilize the related information. With respect to the processing of image data, it is certain that the optimal method should be come up with reflecting the unique characteristics and utilization of image data, apart from the traditional way of processing and storing the legacy text-based data. The study suggests the system of indexing and implementing design image information through the case of analyzing design image data, abstracting data elements of image itself, and finally applying it to building image-oriented database for use.

• Journal of Internet Computing and Services
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• v.3 no.2
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• pp.69-77
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• 2002

Recently, Digital video is one of the important information media delivered on the Internet and playing an increasingly important role in multimedia. This paper proposes a Video Browsing Service(VBS) that provides both the video content retrieval and the video browsing by the real-time user interface on Web, For the scene segmentation and key frame extraction of video sequence, we proposes an efficient scene change detection method that combines the RGB color histogram with the $x^2$(Chi Square) histogram. Resulting key frames are linked by both physical and logical indexing, This system involves the video editing and retrieval function of a VCR's, Three elements that are the date, the field and the subject are used for video browsing. A Video Browsing Service is implemented with MySQL, PHP and JMF under Apache Web Server.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.291-304
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• 2019

This paper proposes a dynamic-tiling-based bandwidth-efficient (DTBE) virtual reality (VR) streaming scheme. We consider 360-degree VR contents with multiple view points such as the front, back, upper, and bottom sides. At a given time, the focus of a client is always bound to a certain view among multiple view points. By utilizing this perspective, under our proposed scheme, tiles with high encoding rates are selectively assigned to the focused view where multiple view points consist of multiple tiles with different encoding rates. The other tiles with low encoding rates are assigned to the remaining view points. Furthermore, for reducing view adaptation delay, we design a novel rapid view adaptation mechanism that selectively delivers an I-frame during view point updates by using frame indexing. We implement the proposed scheme on a commercial VR test bed where we adopt the MPEG media transport (MMT) standard with high-efficiency video coding (HEVC) tile modes. The measurement-based experiments show that the proposed scheme achieves an average data usage reduction of almost 65.2% as well as average view adaptation delay reduction of almost 57.7%.