• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.334-336
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• 2006

최근 들어 인터넷, 인트라넷을 통해 양질의 동영상 데이터를 네트워크 상으로 실시간 또는 사용자의 요구에 따라 전승해 주는 스트리밍 서비스에 대한 요구가 증가하고 있다. 아울러, 유비쿼터스 환경의 도래와 함께 센싱을 통한 다양한 멀티미디어 서비스의 확장이 이루어지고 있으며, 유/무선 환경에서 사용자의 콘텐트에 대한 요구를 끊김 없이/연속 이동을 통해 볼 수 있는 사용자 맞춤형 서비스가 필요로 되고 있다. 이에 본 논문에서는 센서기기를 연동해서 사용자를 인식하고 양질의 동영상을 사용자의 요구 시점에 이동성을 보장하면서 사용자의 다양한 단말 조건을 인식하여 멀티미디어 서비스를 제공하는 내용을 담고 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.1311-1314
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• 2017

이 논문은 비콘과 QR코드를 이용해 방문자 식별 및 원격제어를 구현한 스마트 도어락 시스템을 제안한다. 1인가구의 지속적인 증가에 따라 도어락에 원격제어와 보안의 필요성이 부각된다. 기존 논문에서는 동영상 전송방식, 블루투스 통신 방식 등 다양한 기술을 이용하여 구현한 도어락 시스템을 제안한다. 하지만 동영상 전송방식은 센서가 방문자를 오판단하는 경우가 발생하고, IoT기반의 실시간 스트리밍 기술을 이용한 도어락은 해제 후에 사용자가 집의 내부를 모니터링할 수 없다. 이 논문은 비콘과 안드로이드 어플리케이션, 라즈베리파이를 이용한 방문자 식별 및 원격제어를 구현한다. 또한 3D 프린팅을 이용하여 제작한 프로토타입을 보인다.

• Journal of Broadcast Engineering
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• v.8 no.4
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• pp.427-436
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• 2003

Many applications that are transport multimedia data through the networks should put existing network structure to practical use. Because the existing network structure and protocols are designed for static data transmission, multimedia applications with timing concept have limitations for using existence. In this paper, we present limitations of existing network structure for multimedia delivery, survey network element's characteristics in side view of multimedia application, present the streaming protocol for realtime multimedia traffic. Lastly, we consider a protocol stack for MPEG-21 Digital Item transmission using these existing protocols.

• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.71-78
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• 2017

A network neutrality is the concept that ISP assures users non-discrimination, interconnection, accessibility for ensuring users without control or interference of equal services in the network. But today a network traffic is growing rapidly in sensitive buffering services as P2P service diffusion and mass video stream service. To manage this problem, ISP violates a net neutrality by control, change and interfere with service. And then the debate about net neutrality is happening. Therefore in this paper, we compare and analyze net neutrality principles, concepts, and legislative policy in the native and foreign. Based on this, we suggested the issues and improvement plan of net neutrality guard line.

• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.153-158
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• 2016

As the number of social network users increases, the information on event such as social issues and disasters receiving attention in each region is promptly posted by the bucket through social media site in real time, and its social ripple effect becomes huge. This study proposes a detection method of events that draw attention from users in specific region at specific time by using twitter data with regional information. In order to collect Twitter data, we use Twitter Streaming API. After collecting data, We implemented event detection system by analyze the frequency of a keyword which contained in a twit in a particular time and clustering the keywords that describes same event by exploiting keywords' co-occurrence graph. Finally, we evaluates the validity of our method through experiments.

• Proceedings of the Korean Society of Computer Information Conference
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• 2024.01a
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• pp.427-430
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• 2024

본 논문에서는 그리드 컴퓨팅에서의 안전한 통신을 위한 양자내성암호 기반 사용자 인증 및 키 교환 프로토콜을 구현하고 성능을 측정한다. 디지털 서명을 통해 사용자를 검증하고 암호키를 교환하여 신뢰할 수 있는 사용자들만이 그리드 컴퓨팅에 참여할 수 있도록 한다. 사용자 인증과 키 교환 과정에 NIST 선정 표준양자내성암호인 ML-DSA와 ML-KEM을 적용하여 양자컴퓨터를 이용한 공격에도 안전할 것으로 기대된다. 본 논문에서는 양자내성암호를 적용한 프로토콜이 기존의 현대암호 기반 전자서명이나 키 교환 과정에 비해 양자내성과 동시에 준수한 사용성을 지녔음을 보인다. 이를 통해 그리드 컴퓨팅의 시스템의 P2P 특성에서 기인하는 보안 문제를 해결하고, 기존에 주로 내부망이나 실시간 스트리밍 서비스에서 활용되던 그리드 컴퓨팅의 인터넷 환경으로의 확장 가능성을 제시한다.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.601-606
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• 2008

When sharing real-time media in the ubiquitous computing environments, due to heterogeneous performance of devices, conflict to users' media service requirements might be occurred. To address the problems, there are extensive researches about media streaming QoS control schemes in the aspects of network or application. However, their deployment has met with difficulty because of critical reasons such as high development cost and system complexity. In this paper, in the level of media services, we propose a negotiation approach to offer improved quality of media services. The proposed approach Constructs video distribution group between producer and consumer services, which target to globally minimize the concession of users' quality requirements Consequently, users can be provided video services in the level of conformation to the users' expectation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1C
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• pp.21-35
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• 2002

Nowadays, in accordance with increasing expectations of multimedia stream service on the internet, a lot of distributed applications are being required and developed. But the models of the existing systems have the problems that cannot support the extensibility and the reusability, when the QoS relating functions are being developed as an integrated modules which are suited on the centralized controlled specific-purpose application services. To cope with these problems, it is suggested in this paper to a distributed QoS management system on CORBA, an object-oriented middleware compliance. This systems we suggested can provides not only for efficient control of resources, various service QoS, and QoS control functions as the existing functions, but also QoS control real-time negotiation and dynamic adaptation in addition. This system consists of QoS Control Management Module(QoS CMM) in client side and QoS Management Module(QoS MM) in server side, respectively. These distributed modules are interfacing with each other via CORBA on different systems for distributed QoS management while serving distributed streaming applications. In phase of design of our system, we use UML(Unified Modeling Language) for designing each component in modules, their method calls and various detailed functions for controlling QoS of stream services. For implementation of our system, we used OrbixWeb 3.1c following CORBA specification on Solaris 2.5/2.7, Java language, Java Media Framework API 2.0 beta2, Mini-SQL 1.0.16 and the multimedia equipments, such as SunVideoPlus/Sun Video capture board and Sun Camera. Finally, we showed a numerical data controlled by real-time negotiation and adaptation procedures based on QoS map information to GUIs on client and server dynamically, while our distributed QoS management system is executing a given streaming service.

• Journal of Broadcast Engineering
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• v.25 no.3
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• pp.305-312
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• 2020

As a demand for a new video coding standard having higher coding efficiency than the existing standards is growing, recently, MPEG and VCEG has been developing and standardizing the next-generation video coding project, named Versatile Video Coding (VVC). Many inter prediction techniques have been introduced to increase the coding efficiency, and among them, an adaptive motion vector resolution (AMVR) technique has contributed on increasing the efficiency of VVC. However, the best motion vector can only be determined by computing many rate-distortion costs, thereby increasing encoding complexity. It is necessary to reduce the complexity for real-time video broadcasting and streaming services, but it is yet an open research topic to reduce the complexity of AMVR. Therefore, in this paper, an efficient technique is proposed, which reduces the encoding complexity of AMVR. For that, the proposed method exploits a special VVC tree structure (i.e., multi-type tree structure) to accelerate the decision process of AMVR. Experiment results show that the proposed decision method reduces the encoding complexity of VVC test model by 10% with a negligible loss of coding efficiency.

• Journal of Digital Contents Society
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• v.19 no.8
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• pp.1545-1554
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• 2018

In order to support the mobility of the wireless devices, at least two APs (Access Points) must be arranged in a single AP area to maintain communication area. In the WLAN (Wireless LAN) environment, seamless handover is one of the most important issues in terms of effective utilization of wireless networks and maximization of services for users. On the other hand, SDN (Software-Defined Networking), which is emerging rapidly in recent years, is revolutionizing network management in terms of flexibility, fine control, and convenience. SDN originally reduces latency time or increases network robustness by real-time flow table control reducing or bypassing paths between switches in LAN-based data centers. In this study, we apply OpenFlow, a SDN platform focused on wired LAN, to a dense WLAN environment using legacy APs to implement and evaluate seamless handover for streaming services of digital contents.