• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.264-268
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• 2007

This article presents the performance evaluation case study of circuit-switched WCDMA R5MSC(Mobile Switching Center) Server and CS-MGW(Circuit Switched Media Gateway) in 3'rd generation mobile telecommunication (UMTS : Universal Mobile Telecommunication System). The presented work adopted circuit switching scenarios recommended by 3GPP(Third Generation Partnership Project) and terrestrial spectrum calculation parameters and its values defined in ITU-R M.2023 and M.1390 to do the case study on performance evaluation of circuit switched system (R5 MSC Server and CS-MGW) in WCDMA core network. This paper describes test results by using simulator which substitutes for wireless section (MS, Node-B, RNC).

• The Transactions of the Korea Information Processing Society
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• v.7 no.7
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• pp.2076-2085
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• 2000

Almost all existing software reliability models are based on the assumptions of he software usage and software failure process. There, therefore, is no universally applicable software reliability model. To develop a universal software reliability model this paper suggests the predictive filter as a general software reliability prediction model for time domain failure data. Its usefulness is empirically verified by analyzing the failure datasets obtained from 14 different software projects. Based on the average relative prediction error, the suggested predictive filter is compared with other well-known neural network models and statistical software reliability growth models. Experimental results show that the predictive filter generally results in a simple model and adapts well across different software projects.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.280-282
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• 2004

본 논문은 현재 서비스 발견(SoNics Discovery) 기술로서 각광을 받고 있는 UPnP(Universal Plug and Play)기반의 서비스 활용 및 관리 기능을 적용하기 위한 센서 네트워크 구조를 제안한다. 이를 통해 센서 네트워크 사용자는 수동적인 설정 없이 센서 노드들을 바로 설치 할 수 있으며, 또한 각 센서들이 제공하는 서비스 및 센서 네트워크 전반에 사용될 수 있는 서비스(가령, 컨텍스트 정의 및 활용, 센서 위치 추적, 동기화, 전원 관리 등)를 쉽게 이용할 수 있고, 또한 이하 센서 네트워크 관리도 원활히 할 수 있게 된다. 그러나 TCP/IP 기반에서 동작하는 UPnP는 초소형의 센서 노드에는 적합지 않다. 이에 본 논문에서는 UPnP에 적합하지 않는 초소형의 센서 노드를 위한 브리지 역할 뿐만 아니라, 센서 네트워크 전반의 관리 서비스를 제공하는 BOSS(Brdige Of Sensors)라는 구조를 제안한다.

• Korea-Australia Rheology Journal
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• v.14 no.4
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• pp.161-174
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• 2002

A new technique for numerical calculation of viscoelastic flow based on the combination of Neural Net-works (NN) and Brownian Dynamics simulation or Stochastic Simulation Technique (SST) is presented in this paper. This method uses a "universal approximator" based on neural network methodology in combination with the kinetic theory of polymeric liquid in which the stress is computed from the molecular configuration rather than from closed form constitutive equations. Thus the new method obviates not only the need for a rheological constitutive equation to describe the fluid (as in the original Calculation Of Non-Newtonian Flows: Finite Elements St Stochastic Simulation Techniques (CONNFFESSIT) idea) but also any kind of finite element-type discretisation of the domain and its boundary for numerical solution of the governing PDE's. As an illustration of the method, the time development of the planar Couette flow is studied for two molecular kinetic models with finite extensibility, namely the Finitely Extensible Nonlinear Elastic (FENE) and FENE-Peterlin (FENE-P) models.P) models.

• Journal of Multimedia Information System
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• v.2 no.1
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• pp.153-162
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• 2015

In today's pervasive computing environments, multimedia content should be adapted to meet various conditions of network connections, terminals, and user characteristics. Scalable Video Coding (SVC) is a key solution for video communication over heterogeneous networks, where user terminals have different capabilities. This paper presents a standard-compliant approach that adapts an SVC bitstream to support multiple users. The adaptation problem is formulated as an optimization problem, focusing on the tradeoff between qualities of different spatial layers of an SVC video. Then the adaptation process is represented by standard metadata of MPEG-21, which can be solved by universal processing to enable interoperable and automatic operation. Our approach provides the users with optimal quality, a wide flexibility, and seamless adaptation. To the best of our knowledge, this is the first study that shows the adaptation tradeoff between spatial layers of a conforming SVC bitstream.

• Electronics and Telecommunications Trends
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• v.27 no.4
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• pp.54-62
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• 2012

미국을 비롯한 영국, 프랑스 등 주요 EU 회원국들은 국가 경쟁력 향상을 위해 초광대역망 구축을 정부 차원에서 추진하고 있다. 초광대역망 투자 계획은 모든 국민에게 통신 서비스를 제공하는 보편적 서비스 제도와 연계하여 추진하고 있다. 특히 미국의 Broadband Plan과 영국의 Digital Britain 계획을 통해 보편적 서비스 제도가 PSTN 음성 서비스에서 데이터 서비스로 전환되고 있다. 이에 반해 호주에서는 초광대역망 구축과 보편적 서비스 제도 개편 움직임이 다른 국가들과 차별되어 국가 차원에서 기업을 설립하고 망 투자와 보편적 서비스 제도를 담당하는 방향으로 움직이고 있다. 본고에서는 호주의 초광대역망 구축 계획을 살펴보고 초광대역망 환경으로 과도기 단계에서 보편적 서비스 제도 개선 현황 및 특징을 살펴보고 시사점을 살펴보고자 한다.

• Electronics and Telecommunications Trends
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• v.27 no.2
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• pp.149-157
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• 2012

최근까지 정체 국면에 있던 3D 산업이 2012년부터는 런던 올림픽과 여수 EXPO 등 글로벌 이벤트 발생으로 관련 산업이 활성화될 것으로 전망되고 있다. BBC 등 글로벌 미디어들도 3D 방송을 본격화할 예정이어서 3D 콘텐츠 시장이 국내외적으로 급성장할 것으로 기대된다. 우리나라는 아직까지 3D 산업이 초기 시장이기 때문에 향후 3D 산업을 육성 발전시키기 위해서는 정부의 역할이 중요하다고 할 수 있다. 본고의 목적은 정부 주도로 연구개발을 수행하면서 3D 연구개발 분야에서 세계를 선도하고 있는 일본의 3D 연구개발 정책동향을 살펴보고, 우리나라에 주는 시사점을 발굴하는 것이다. 이러한 목적을 달성하기 위하여 본고에서는 'UNS(Universal Communications, New Generation Networks, Security and Safety for the Ubiquitous Network Society) 전략 프로그램 II'를 중심으로 일본의 3D 기술개발 관련 주요 전략을 살펴 보았으며, 3D 기술개발을 위한 R&D 조직인 NICT(National Institute of Information and Communication Technology) 및 URCF(Ultra-Realistic Communications Forum)의 역할을 소개하는 한편, 일본의 3차원 영상기술에 의한 초현장감 커뮤니케이션 기술개발의 현황과 전망을 고찰하였다.

• IEMEK Journal of Embedded Systems and Applications
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• v.2 no.4
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• pp.242-250
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• 2007

Wireless sensor networks are subject to highly heterogeneous system requirements in terms of their functionality and performance due to their broad application areas. Though the heterogeneity hinders the opportunity of developing a single universal platform for sensor networks, efforts to provide uniform, inter-operable and scalable ones for sensor networks are still essential for the growth of the industry as well as their technological advance. As a part of our work to develop such a robust platform, this paper presents the software architecture for sensor nodes with focus on our sensor node operating system and its configuration methodology. Addressing principle issues in its design space which includes programming, execution, task scheduling and software layer models, our architecture is highly reconfigurable with respect to system resources and functional requirements and also highly efficient in supporting multi-threading under small system resources.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.5
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• pp.852-857
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• 2008

A new adaptive neuro-control algorithm for a SISO strict-feedback nonlinear system is proposed. All the previous adaptive neural control algorithms for strict-feedback nonlinear systems are based on the backstepping scheme, which makes the control law and stability analysis very complicated. The main contribution of the proposed method is that it demonstrates that the state-feedback control of the strict-feedback system can be viewed as the output-feedback control problem of the system in the normal form. As a result, the proposed control algorithm is considerably simpler than the previous ones based on backstepping. Depending heavily on the universal approximation property of the neural network (NN), only one NN is employed to approximate the lumped uncertain system nonlinearity. The Lyapunov stability of the NN weights and filtered tracking error is guaranteed in the semi-global sense.

• Journal of the Korea Computer Industry Society
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• v.2 no.6
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• pp.845-852
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• 2001

Electronic commerce and application service is to universal on the internet, and a large quantity information transmitted on the network, It's needs procedure to access only permit objects for the integrity of information. In order to provide regional services is authentication for control resource and client identification. In particular, public key system is to implement in distributed environment, it is able to insurance users convenience and integrity at the same time. In this paper designed mechanism of cross certification between realms in PKI based on X.509 associated with DNS (Domain Name System) that is presented.