• Journal of Broadcast Engineering
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• v.25 no.5
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• pp.709-722
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• 2020

Point Cloud which is a cluster of numerous points can express 3D object beyond the 2D plane. Each point contains 3D coordinate and color data basically, reflectance or etc. additionally. Point Cloud demand research and development much higher effective compression technology. Video-based Point Cloud Compression (V-PCC) technology in development and standardization based on the established video codec. Despite its high effective compression technology, point cloud service will be limited by terminal spec and network conditions. 2D video had the same problems. To remedy this kind of problem, 2D video is using Scalable High efficiency Video Coding (SHVC), Dynamic Adaptive Streaming over HTTP (DASH) or diverse technology. This paper proposed a density scalability method using SHVC codec in V-PCC.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.2
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• pp.213-222
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• 2017

Online advertisement has many benefits comparing to offline advertisement but it also has many challenging problems by online ad abuses. Advertisement injection (Ad injection) is one of the threats that surreptitiously inserts advertisements without a permission of site owners. Users are exposed to additional ads and redundant web traffic by injected ads can cause a service quality problem. Moreover, advertisers can have economic loss when injected ads are different from original ones. Although ad injection leads to these problems it has not been fully studied yet. A few ad injection researches are done by online advertising providers such as Google. In this paper, we analyze ad injection activities to Korean major portal, Naver. We classify 6 types of ad injections and describe their characteristics by analyzing 27 downloaders and 199 installed programs.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.3
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• pp.261-265
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• 2008

As increasing the user of VoIP service using ITSP(Internet Telephony Service Provider), the VoIP spam becomes a big problem. The spam used in the existing public telephone is detected by using the pattern inspection of call behavior because it is difficult to filter contents for the characteristic of real-time voice communication. However there is a false-positive problem. The threat on spam remains where spam with low threshold can't be detected or users share one number. In this paper, we propose anti-spam for VoIP based on luring test. The proposed method gives a user luring test and he/she can connect to a receiver if passing turing test. A ticket is given to a user that pass luring test and it reduces overhead of luring test in re-dial. The proposed method is implemented on ASUS WL-500G wireless router and Asterisk IP-PBX. Experimental results show the effectiveness of the proposed method.

• Journal of the Korean Society for information Management
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• v.31 no.4
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• pp.69-102
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• 2014

In this study, we propose an approach of building a portal site that can offer integrated services for textbook through special libraries For this purpose, we analyzed previous related studies and investigated textbook portal construction sites domestically and abroad. Based on this research, we developed survey questions and conducted a survey targeting users of textbook libraries. As a result, the following projects are required for creating a textbook library: a comprehensive list of textbooks and other content construction, digitization projects of library holdings, collection and delivery of various textbook-related reference books, building a textbook database by topic, collecting and providing textbook-related research publications, a cooperation network with textbook-related organizations, and active promotion of portal sites.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.610-613
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• 2010

본 과제를 통하여 기술적으로는 로봇 개발에 있어 기존 기술을 최대한 활용하고 새로운 기능을 추가하는 형태로 발전해 갈 수 있도록, 각 요소별 기능을 표준화 모듈화 하여 새로운 제품의 개발이 손쉽게 이루어 질 수 있는 기본 platform으로의 역할이 가능해졌다. 구동부 제작 및 설계, 금형 비용 등을 절감하기 위한 다목적 완구로봇 플랫폼을 확보할 수 있었다. 로봇이 복잡한 환경을 인식하고, 자율적으로 작업을 수행하며, 예측하지 못한 문제에 적절한 대처를 할 수 있도록 하기 위한 핵심 기술을 제공하게 될 것으로 생각된다. 로봇 개발에 있어 전문지식이 없는 초보자들이 직접 제작 구동해 볼 수 있는 비주얼한 개발환경을 지원할 뿐만 아니라 GUI 개발환경 및 TEXT Programming 으로 상호 전환이 가능한 코딩 방법을 지원(MSRS와의 차별화를 시도하였다. 기존 하드웨어 지식과 소프트웨어지식이 없는 상태에서도 제작자의 창의력에 따라 다양한 형태의 로봇을 제작 적용이 용의 하며 초보자들에 대한 로봇개발에 흥미를 유발할 수 있도록 하였다. 고급사용자를 위한 별도의 다운로딩 포트를 제공하였다. 로봇공학의 기본지식을 습득(아날로그/디지털 회로를 이해하고, 각종 센서의 이해하며, 스템/서보/DC모터의 제어기술, 펌웨어개발능력, 기본수준의 소프트웨어개발 능력) 활용할 수 있다. 또한, 경제 및 산업적 측면으로는 다음과 같은 장점이 있다. 기존 기술들의 장점을 취합하여 추가적인 기술을 적용할 수 있는 Base형태의 로봇을 개발할 경우 이를 활용한 제품 개발 및 Base자체로도 충분한 시장을 형성 할 수 있을 것으로 기대된다. 인터넷기반 로봇 제어 기술의 확보로 로봇시스템의 생산비용을 낮추고 TTM (Time-to-Market) 제약을 해결시켜 준다. 다른 응용 시스템에 쉽게 적용이 가능하고 지식기반 로봇 서비스의 요소기술 개발은 멀티미디어 콘텐츠분야(교육/게임/오락 등)의 활성화가 가능하기 때문에 타 IT산업에의 파급효과가 예상된다. B2B를 통한 실질적인 판매를 통한 동종기업의 연구 개발비 및 개발 기간의 단축이 예상된다.

• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.540-546
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• 2010

Since the stereoscopic 3-dimensional (3D) video that provides users with a realistic multimedia service requires twice as much data as 2-dimensional (2D) video, it is difficult to construct the fast system. In this paper, we propose a fast stereoscopic 3D broadcasting system based on the depth information. Before the transmission, we encode the input 2D+depth video using x264, an open source H.264/AVC fast encoder to reduce the size of the data. At the receiver, we decode the transmitted bitstream in real time using a compute unified device architecture (CUDA) video decoder API on NVIDIA graphics processing unit (GPU). Then, we apply a fast view synthesis method that generates the virtual view using GPU. The proposed system can display the output video in both 2DTV and 3DTV. From the experiment, we verified that the proposed system can service the stereoscopic 3D contents in 24 frames per second at most.

• Journal of Broadcast Engineering
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• v.20 no.4
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• pp.497-508
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• 2015

Current communication networks consist of channels with various throughputs, protocols, and packet loss rates. Moreover, there are also diverse user multimedia consumption devices having different capabilities and screen sizes. Thus, a practical necessity of scalability on video coding have been gradually increasing. Recently, The Scalable High Efficiency Video Coding(SHVC) standard is developed by Joint Collaborative Team on Video Coding(JCT-VC) organized in cooperation with MPEG of ISO/IEC and VCEG of ITU-T. This paper introduces coding tools of SHVC including adopted and unadopted tools discussed in the process of the SHVC standardization. Furthermore, the individual tool and combined tool set are evaluated in terms of coding efficiency relative to a single layer coding structure. This analysis would be useful for developing a fast SHVC encoder as well as researching on a new scalable coding tool.

• Journal of Broadcast Engineering
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• v.22 no.3
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• pp.366-374
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• 2017

Since a display device such as TV or digital signage is getting larger, the types of media is getting changed into wider view one such as UHD, panoramic and jigsaw-like media. Especially, panoramic and jigsaw-like media is realized by stitching video clips, which are captured by different camera or devices. However, a stitching process takes long time, and has difficulties in applying for a real-time process. Thus, this paper suggests to find out 2D Adjacency Matrix, which tells spatial relationships among those video clips in order to decrease a stitching processing time. Using the Discrete Cosine Transform (DCT), we convert the each frame of video source from the spatial domain (2D) into frequency domain. Based on the aforementioned features, 2D Adjacency Matrix of images could be found that we can efficiently make the spatial map of the images by using DCT. This paper proposes a new method of generating 2D adjacency matrix by using DCT for producing a panoramic and jigsaw-like media through various individual video clips.

• Journal of the Institute of Convergence Signal Processing
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• v.17 no.1
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• pp.40-45
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• 2016

In accordance with the digital broadcast data converted, the number of the service provider, and content channel for interaction with the viewer has increased exponentially. Electronic program guide in such a multi-channel time(Electronic Program Guide, EPG) is an essential requirement, and also from day to day EPG generation technique according to the user's requirements. But the current situation is getting EPG to viewers outside for reasons such as absence, lack of accurate information, organizing techniques utilized lack of standard systems. In this article, we describe the State and EPG solution to the problem of these terrestrial stations. This, the EPG information and the actual broadcast time of the terrestrial channel 6 using a ground wave receiving method for a direct comparison was studied the problems and the average error of the current start. Also this research perform to enhance accuracy of EPG information.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11C
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• pp.1049-1058
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• 2009

After the efficiency of H.264 video compression has been announced, it replaced MPEG-2 standard in several applications. So transcoding methods of MPEG-2 to H.264 have been studying because there are variety devices and contents followed by MPEG-2. Although H.264 supported various service such as IPTV, DMB, digital broadcasting etc, but users using MPEG-2 devices cannot accessible to them. This paper propose H.264 to MPEG-2 transcoding for users of MPEG-2 devices without displacement H.264. The proposed method predicted a motion vector for MPEG-2 encoder after it extracted from motion vectors of variable blocks in H.264 to improve processing time. Also it predicted a optimal motion vector using modified boundary matching algorithm after grasped a special character for boundary and background of object. The experimental results from proposed method show a considerable reduction in processing time, as much as 65% averagely, with a small objective quality reduction in PSNR.