• ETRI Journal
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• 제34권5호
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• pp.791-794
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• 2012

We propose an efficient framework to realistically render 3D faces with a reduced set of points. First, a robust active appearance model is presented to detect facial features in the projected faces under different illumination conditions. Then, an adaptive simplification of 3D faces is proposed to reduce the number of points, yet preserve the detected facial features. Finally, the point model is rendered directly, without such additional processing as parameterization of skin texture. This fully automatic framework is very effective in rendering massive facial data on mobile devices.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.148-153
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• 2009

Few methods have dealt with segmenting multiple images with analogous content. Concurrent images of a scene and gathered images of a similar foreground are examples of these images, which we term consistent scene images. In this paper, we present a method to segment these images based on manual segmentation of one image, by iteratively propagating information via multi-level cues with adaptive confidence. The cues are classified as low-, mid-, and high- levels based on whether they pertain to pixels, patches, and shapes. Propagated cues are used to compute potentials in an MRF framework, and segmentation is done by energy minimization. Through this process, the proposed method attempts to maximize the amount of extracted information and maximize the consistency of segmentation. We demonstrate the effectiveness of the proposed method on several sets of consistent scene images and provide a comparison with results based only on mid-level cues [1].

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.159-164
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• 2004

This paper aims towards designing and implementation of a new adaptive Peer to Peer (P2P) network that cluster itself on the basis of semantic proximity. We also developed an algorithm to classify the nodes to form the semantic groups and to direct the queries to appropriate groups without any human intervention. This is done using Bloom filters to summarise keywords of the documents shared by a peer. The queries are directed towards the appropriate clusters instead of flooding them. The proposed topology supports a system for maintaining a global, omnipresent trust value for each peer in an efficient manner both in terms of decision time and network load.

• Journal of Information Processing Systems
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• 제15권2호
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• pp.261-270
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• 2019

In order to protect secret digital documents against vulnerabilities while communicating, steganography algorithms are applied. It protects a digital file from unauthorized access by hiding the entire content. Pixel-value-difference being a method from spatial domain steganography utilizes the difference gap between neighbor pixels to fulfill the same. The proposed approach is a block-wise embedding process where blocks of variable size are chosen from the cover image, therefore, a stream of secret digital contents is hidden. Least significant bit (LSB) substitution method is applied as an adaptive mechanism and optimal pixel adjustment process (OPAP) is used to minimize the error rate. The proposed application succeeds to maintain good hiding capacity and better signal-to-noise ratio when compared against other existing methods. Any means of digital communication specially e-Governance applications could be highly benefited from this approach.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권5호
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• pp.2544-2557
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• 2019

Adaptive bitrate streaming is a crucial element in the implementation of high-quality streaming of media content over the Internet. Dynamic adaptive streaming over HTTP (MPEG-DASH) has lately emerged as the de facto solution for over-the-top (OTT) video streaming services. In this paper, we perform macro-level analysis on a real-world MPEG-DASH-based Internet live broadcasting service to gain insight into its behavior throughout the end-to-end service-provision chain, from broadcasters to viewers. Based on this analysis, we propose methods to improve the quality-of-experience (QoE) of MPEG-DASH-based services, particularly with regard to reducing broadcasting delays between recording and viewing of videos, as well as synchronizing client terminals.

• 방송공학회논문지
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• 제17권2호
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• pp.207-222
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• 2012

최근 3D 입체영상에 대한 소비자들의 관심 증대로 가전 업체들은 3D TV, 3D Monitor등의 제품들을 출시하고 있고, 이에 따라 3D 콘텐츠 시장도 급격히 성장할 것으로 예상된다. 그러나 이러한 3D 콘텐츠를 서비스함에 있어서 보다 높은 대역폭이 요구되어지므로 QoS(Quality of Service)를 보장하지 않는 IP 기반 전송환경에서의 고화질 3D 스트리밍 서비스는 소비자에게 끊김 없는 영상서비스를 제공하는데 제약이 있다. 이러한 문제를 해결하기 위해서, IP 망 네트워크 환경을 고려하여 사용자들이 원하는 콘텐츠를 네트워크 환경에 따라 적절한 품질로 제공 할 수 있는 적응적 스트리밍 서비스 기술이 현재 국제 표준화 기구인 MPEG(Moving Picture experts Group)에서 DASH(Dynamic Adaptive Streaming over HTTP)라는 이름으로 표준화가 진행 중에 있다. 그러나 DASH에서는 독립된 좌, 우 영상이 단일 segment안에 2개의 Elementary Stream(ES)으로 구성되어 있는 service- compatible 기반의 스테레오스코픽 콘텐츠에 대한 명확한 scheme이 나타나지 않는다. 따라서 본 논문에서는 DASH를 이용한 service-compatible 기반의 효율적인 적응적 3D 스트리밍 서비스 제공 방안을 제안한다. DASH를 이용한 3D 서비스는 사용자들에게 IP 망을 통한 다양한 품질의 3D 콘텐츠를 제공함으로써 끊김 없는 3D 스트리밍 서비스가 가능하고, 또한 하나의 3D 콘텐츠로 다양한 디바이스에 적용 가능하다는 이점이 있다.

• 방송공학회논문지
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• 제22권1호
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• pp.95-106
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• 2017

디지털 방송 통신 기술의 발전에 따라 고화질 방송 서비스와 함께 컴패니언 스크린 서비스에 대한 관심이 높아지고 있다. 개인 모바일 디바이스 사용이 확산됨에 따라 주 스크린에서 양질의 방송을 제공 하는 것 뿐 아니라 세컨드 스크린에서 부가적인 가치를 창출하는 것도 중요하다. 본 논문에서는 사용자의 컨텍스트에 의거하여 적응적인 컴패니언 서비스를 만드는 플랫폼과 관련 저작 도구를 제안한다. 이를 위해 사용자의 상황에 기반하여 원격으로 리소스를 모으고 조합하여 적응적인 컴패니언 스크린 서비스를 공급하는 플랫폼을 설계하였고 실제 서비스 환경에 맞게 구현하였다. 제안하는 플랫폼은 사용자의 다양한 컨텍스트와 사업자의 요구를 고려하여 양질의 컨텐츠를 실시간 구성하고 사용자에게 제공할 수 있으며 플랫폼 기반 저작 도구는 숙련되지 않은 디자이너와 서비스 기획자도 적응적 컴패니언 스크린 서비스를 쉽고 빠르게 만들 수 있도록 한다. 설계한 플랫폼을 이용하여 인터랙티브 서비스 제공이 가능한 한국 UHD IBB 표준을 준수하는 컴패니언 스크린 서비스 컨텐츠를 만들고 시뮬레이션 하였다.

• 정보처리학회논문지D
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• 제8D권5호
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• pp.613-622
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• 2001

디지털 자원에 대한 유통환경의 급속한 변화에 따라 디지털자원에 대한 지적재산권 보호 문제가 중요하게 대두되고 있다. 디지털자원의 접근과 이용에 대한 신뢰있는 환경을 만들기 위한 통합적인 접근방법으로 디지털저작권관리(DRM)기술에 대한 관심이 디지털컨텐츠 저자나 출판사, ISP를 중심으로 높아지고 있다. 본 논문에서는 현재의 디지털저작관리기술이 직면하고 있는 취약점인 정적인 저작권관리 문제와 해결과 감시 및 추적기능 보강을 위하여 적응형 에이전트 기술(ARPA : Adaptive Resource Protection Agent)에 기반한 동적 디지털저작관리 시스템을 제안한다. 여기에서 동적 디지털저작권 관리를 위하여 동적미션제어 기법이 적용되고 온라인 및 오프라인 상에서의 컨텐츠 보호와 감시를 위하여 적응형 에이전트 기술이 적용된다. 또한, 프로토타입시스템을 구현하여 동적으로 디지털저작권을 보호하는 과정을 보인다.

• 대한간호학회지
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• 제39권2호
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• pp.259-269
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• 2009

Purpose: The aim of this study was to develop a breast feeding adaptation scale (BFAS) to evaluate adaptation to breastfeeding for breastfeeding mothers and their infants and to test the validity and reliability of the instrument. Methods: The study was conducted as follows: application of the conceptual framework, identification of the content domains, items generation, and test of validity and reliability. In order to test validity and reliability, two panels of experts reviewed items and subcategories of the preliminary questionnaire and then data were collected from 329 mothers who were up to 4 weeks postpartum and breastfeeding. Descriptive statistics, t-test, factor analysis, and Cronbach's alpha were used to analyze the data. Results: The conceptual framework was based on the Roy adaptation model. The content domains were developed via literature review, review of instruments, and data acquired from the interviews of breastfeeding mothers and nurses. A total of 69 items belonging to 8 domains were generated. A reduction to 44 preliminary items was accomplished through content validity analysis. Factor analysis extracted 8 factors with a total of 27 items on a 5-point Likert scale. Content validity, construct validity, criterion validity, and reliability of the BFAS were established. Conclusion: The newly developed BFAS is a reliable and valid instrument with which the adaptation of breastfeeding mothers and their infants to the breastfeeding behavior can be evaluated.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권8호
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• pp.3121-3135
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• 2015

Owing to the increase in consumption of multimedia content and the improvement of device capacity, user demand for high-quality content has increased. However, it is difficult to transport such large amounts of content over the existing broadcasting network with limited bandwidth. To provide high-definition broadcasting, some studies suggest methods of transporting multimedia over heterogeneous networks after encoding content hierarchically. MPEG Media Transport (MMT), standardized by Moving Picture Experts Group (MPEG), is a solution that enables large-volume media transport over heterogeneous networks such as digital broadcasting networks and packet-switched networks. In the case of delivering a scalable encoded video over different networks, synchronization of each stream is an important issue. MMT defines a synchronization scheme, but does not contain sufficient functions to implement it. In this paper, we propose a synchronization scheme for media streams that are encoded hierarchically, divided into layers, and transported over heterogeneous networks. We implement our scheme using MMT and HTTP, and experimented using three encapsulated video streams with different durations. As a result, we show that the proposed scheme can reduce the waiting time to display high-quality video, relative to Dynamic Adaptive Streaming over HTTP-Scalable Video Coding (DASH-SVC) by requesting segments of enhanced layers after calculating the transmission time. Additionally, we find out that the selection of durations have a relation to the characteristics of the video.