• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2018년도 하계학술대회
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• pp.260-261
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• 2018

MPEG과 VCEG은 차세대 비디오 부호화 표준 기술 개발를 위한 JVET(Joint Video Exploration Team)을 구성하여 현재 비디오 표준화인 HEVC 대비 높은 부호화 효율을 목표로 연구를 진행하며 CfP(Call for Proposal) 단계를 진행 중이다. JVET의 공통 플랫폼인 JEM(Joint Exploration Test Model)은 HEVC의 quad-tree 기반 블록 분할 구조를 대신하여 더 많은 유연성을 제공하는 QTBT(Quad-tree plus binary-tree)가 적용되었다. QTBT는 화면 내 부호화 효율을 높이기 위한 하나의 방법으로 휘도와 색차 신호에 대해 분할된 블록 구조를 지원한다. 이러한 방법은 채널 간 블록 분할 모양이 동일하거나 비슷한 경우에 중복되는 블록 분할 신호가 발생할 수 있는 단점이 있다. 따라서 본 논문에서는 화면 내 부호화에서 채널 간 유사도 비교를 이용하여 적응형 색차 블록 방법을 제안한다. 제안한 방법의 실험 결과로 JEM 6.0과 비교하여 CfE(Call for Evidence) 영상에서 평균 0.28%의 Y BD-rate 감소와 함께 평균 124.5%의 부호화 복잡도 증가를 확인하였다.

• ETRI Journal
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• 제35권1호
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• pp.7-17
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• 2013

The ongoing proliferation of new services, applications, and contents is leading the Internet to an architectural crisis owing to its inability to provide efficient solutions to new requirements. Clean-slate architectures for the future Internet offer a new approach to tackle current and future challenges. This proposal introduces a novel clean-slate architecture in which the TCP/IP protocol stack is decoupled in basic functionalities, that is, atomic services (ASs). A negotiation protocol, which enables context-aware service discovery for providing adapted communications, is also specified. Then, we present how ASs can be discovered and composed according to requesters' requirements. In addition, a media service provisioning use case shows the benefits of our framework. Finally, a proof-of-concept implementation of the framework is described and analyzed. This paper describes the first clean-slate architecture aligned with the work done within the ISO/IEC Future Network working group.

• 복식문화연구
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• 제24권3호
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• pp.367-384
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• 2016

The aim of this paper is to examine relationship characteristics and the relevance there of in the context of the Chanel collection, between the contemporary fashion show viewed from the artistic side and intermedia on interaction. This study analyzed the relationship characteristics between intermedia and fashion shows by focusing on Chanel fashion shows from 2010 S/S to 2016 F/W as actual case. The results are as follow: First, participational accessibility indicates the experience of a designer and audience in active participation changing into passive participation. Second, audience immersion is represented by the perception of being involved by the audience in the place and acting. Third, conceptual symbolism is sending of messages through the designer's concept manifesting in the specific features of the design. Finally, expandability of media explains trans-boundaries in experimental attempts. It concludes that fashion show is a space where the audience can have visual as well as new knowledge and experience through multi-sensory channels. The Chanel collection which is considered a huge art project at the fashion show, showed a relationship between philosophy and the direction through season concepts and brands. The Chanel collection has brought a new experience through the convergence of communications and cultural media, such as music and art according to traditional brand image.

• 방송공학회논문지
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• 제11권1호
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• pp.130-137
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• 2006

본 논문에서는 통신 방송 융합 환경하에서 다양한 이동 통신 단말을 가지고 있는 최종 소비자에게 멀티미디어 콘텐츠를 서비스 ( 간단히, UCA(Ubiquitous Contents Access) 라고 함) 해 주는 기술들을 소개하고 이 기술들이 적용된 서비스 모텔을 제안한다. 또한 제안된 서비스 기술에 대해 소비자 측면에서 보이는 서비스 기술의 상대적 우위성과 유희성을 분석하였다. 이와 같이 소비자 관점에서 바라본 통방 융합 서비스 기술에 대해 소비자 관점의 상대적 우위성 및 유희성을 분석함으로써 제안된 통신 방송 융합 서비스 모델이 소비자가 선호할 수 있는 가치 있는 서비스임을 알 수 있다.

• 한국IT서비스학회지
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• 제10권4호
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• pp.149-169
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• 2011

As the number of smart phone users increases, many organizations begin to adopt social media rapidly to diversify communication channels with customers. Specifically, twitter, which supports instant and two-way communications between users and between organizations and users, has been adopted by many organizations as an efficient way not only to identify new customers but also to retain existing customers. However, little attention has been given to the issue on how organizations can effectively use twitter to improve customer satisfaction. To explore the issue, this study proposes two major dimensions, customer participation and organization resource utilization, which should be considered in building a utilization strategy for twitter in organizations. We then develop four different combinations along with these dimensions-follow, mention, retweet, and review types. Based on case studies of 27 organizations that use twitter, we evaluate the degrees of customer participation, resource utilization, and customer satisfaction, and examine matching or mismatching of the adoption purpose of twitter and its actual utilization. The study results reveal that organizations in the matching group show higher customer satisfaction that those in the mismatching group. This study sheds new light on twitter research by developing a new conceptual framework and using a case study approach to explore the relationship between the utilization strategy of twitter and customer satisfaction.

• 한국통신학회논문지
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• 제29권11B
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• pp.991-1000
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• 2004

최근까지 네트워크 계층에서 수행되는 IP 멀티캐스트는 많은 관심과 연구가 진행되고 있다. 하지만 유니캐스트 라우터들로 구성된 현재의 인터넷 망에서 IP 멀티캐스트의 적용은 불가능한 상태이다. 때문에 응용계층 멀티캐스트가 IP 멀티캐스트의 대안으로 제시되고 있다. IP 멀티캐스트가 네트워크 라우터들에 의존적인 반면 응용계층 멀티캐스트는 네트워크 계층과 독립적으로 수행된다. 본 논문에서는 실시간 미디어의 효과적인 전송을 위한 source에서 end-system들에 이르는 평균 지연 시간을 최소화하는 응용계층 멀티캐스트 트리 구성 알고리즘을 제안한다. 제안하는 알고리즘은 제어 변수로써 각 end-system들의 계산 수행능력과 네트워크 조건을 고려하며 트리를 구성하는 몇몇 end-system들에게만 부하가 집중되는 현상을 방지하도록 구성되었다. 제안하는 알고리즘에 의한 응용계층 멀티캐스트 트리는 clustering과 변형된 Dijkstra 알고리즘에 의해 구성된다. 즉, source와 proxy-sender들 사이의 트리와 각 cluster안에서 트리를 구성함으로써 전체 트리를 생성한다. 실험을 통하여 제안하는 알고리즘이 기존 알고리즘 보다 효과적임을 보였다.

• 한국통신학회논문지
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• 제36권5A호
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• pp.464-472
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• 2011

우선 센서 네트워크 기술이 환경 감시나 재난 감시와 같은 다양한 용용 분야에 적용되면서 지중 환경에서의 무선통신에 대한 필요성이 증가하고 있다. 특히, 지중에서는 기존의 전자기파를 이용한 우선 통신 방식이 비효율이기 때문에 그 대안으로서 자기장을 이용한 지중 통신 기술이 제시되었고, 최근 들어 자기장 통신 기술이 국내 KS 규격으로 제정되었다. 본 논문에서는 KS 규격으로 제정된 자기장 통신 매체 접근 제어(Media Access Control) 프로토콜의 성능을 분석 및 시뮬레이션 방법을 통해서 분석한다.

• 대한임베디드공학회논문지
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• 제2권1호
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• pp.53-59
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• 2007

Wimedia UWB(Ultra-Wideband) platform provides data rates up to 480Mbps in WPAN (Wireless Personal Area Network). Wimedia conformant devices access to the channels through superframe concept for communications. As the channel resource is limited, the optimal channel time required for each device needs to be estimated to share the resource efficiently among the devices. In this paper, we propose a scheme to estimate the required channel time in a super frame to satisfy the QoS of the application on a device. The channel time is estimated from the service rate which is computed from the TSPEC of the application. In the process of the estimation, we take the frame overhead for data transmission as well as the overhead due to the acknowledgement scheme, preamble, and MDSU size into consideration. We also analyze and compare the throughputs for different acknowledgement scheme, preamble, and MDSU size situations. The estimated channel time required for a given service rate is allocated in the unit of MAS(Medium Access Slot).

• Journal of Communications and Networks
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• 제13권3호
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• pp.277-285
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• 2011

Real-time multimedia streaming over the Internet is rapidly increasing with the popularity of user-created contents, Web 2.0 trends, and P2P (peer-to-peer) delivery support. While many homes today are broadband-enabled, the quality of experience (QoE) of a user is still limited due to frequent interruption of media playout. The vulnerability of TCP (transmission control protocol), the popular transport-layer protocol for streaming in practice, to the packet losses, retransmissions, and timeouts makes it hard to deliver a timely and persistent flow of packets for online multimedia contents. This paper presents TCP-real-time online multimedia environment (ROME), a novel transport-layer framework that allows the establishment and coordination of multiple many-to-one TCP connections. Between one client with multiple home addresses and multiple co-located or distributed servers, TCP-ROME increases the total throughput by aggregating the resources of multiple TCP connections. It also overcomes the bandwidth fluctuations of network bottlenecks by dynamically coordinating the streams of contents from multiple servers and by adapting the streaming rate of all connections to match the bandwidth requirement of the target video.

• 한국통신학회논문지
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• 제35권11A호
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• pp.1085-1090
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• 2010

Ultra wideband (UWB) technologies have been developed to exploit a new spectrum resource in substances and to realize ultra-high-speed communication, high precision geolocation, and other applications. The energy of UWB signal is extremely spread from near DC to a few GHz. This means that the interference between conventional narrowband systems and UWB systems is inevitable. However, the interference effects had not previously been studied from UWB wireless systems to conventional mobile wireless systems sharing the frequency bands such as Cellular CDMA and Korean PCS. This paper experimentally evaluates the interference from two kinds of UWB sources, namely a direct-sequence spread-spectrum UWB source and an impulse radio UWB source, to a Cellular CDMA and K-PCS digital transmission system. The average frame error rate degradation of each system arc presented. From these experimental results, we show that in all practical cases UWB system can coexist with Cellular CDMA and K-PCS terminal without causing any dangerous interference.