• 기술사
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• 제31권2호
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• pp.65-72
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• 1998

For the flow facing highly informationized age, there Is a flow from fixed communications connecting fixed places such as offices and homes to mobile communications connecting mobile objets such as automobiles, ships and aircraft. This flow has added to diversifying communications including data and images. While the fixed mode Is diversifying information media by digitalization of communications network and computers, the mobile mode has brought higher sophistication of communication modes by a higher degree of electric wave utilization. The following descriptions outlines the mobile communication which Is utilizing the electric wave phenomena. In sequence the following items are described: a brief history of mobile communications, the technical object and various kinds of services, propagation of electric wave signal.

• 한국통신학회:학술대회논문집
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• 한국통신학회 2006년도 하계종합학술발표회 논문 초록집
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• pp.673-673
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• 2006

• 정보보호학회논문지
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• 제23권2호
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• pp.169-179
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• 2013

최근 스마트 폰, 스마트 패드와 같은 모바일 디바이스의 발전과 무선 네트워크 및 이동통신 네트워크의 발전으로 모바일 디바이스를 이용하는 서비스는 증가하고 있다. 그러나 무선 네트워크는 유선 네트워크에 비해 보안에 취약하므로 보다 강한 보안의 적용이 필요한 반면 배터리 기반의 모바일 디바이스는 낮은 계산 능력과 메모리 공간의 제약 및 무선통신에 사용되는 비용이 높기 때문에 보안의 적용은 효율적이어야 한다. 따라서 본 논문에서는 모바일 디바이스를 이용한 서비스에서 요구되는 보안 요구사항을 충족시키고 모바일 환경에 적합한 티켓 기반의 인증 기법을 제안한다.

• ETRI Journal
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• 제34권6호
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• pp.922-931
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• 2012

With the increasing demands for mobile wireless sensor networks in recent years, designing an energy-efficient clustering and routing protocol has become very important. This paper provides an analytical model to evaluate the power consumption of a mobile sensor node. Based on this, a clustering algorithm is designed to optimize the energy efficiency during cluster head formation. A genetic algorithm technique is employed to find the near-optimal threshold for residual energy below which a node has to give up its role of being the cluster head. This clustering algorithm along with a hybrid routing concept is applied as the near-optimal energy-efficient routing technique to increase the overall efficiency of the network. Compared to the mobile low energy adaptive clustering hierarchy protocol, the simulation studies reveal that the energy-efficient routing technique produces a longer network lifetime and achieves better energy efficiency.

• 한국정보통신학회논문지
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• 제13권4호
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• pp.658-667
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• 2009

네트워크 이동성은 모바일 라우터를 도입해 네트워크 내의 다수의 노드들에게 이동성을 지원하는 방법이다. 본 논문에서는 네트워크 이동성의 이점에 대해 기술하고, 이를 토대로 네트워크 이동성의 성능 향상을 위한 요구 사항을 제시하고, 네트워크 이동성을 구성하는 주요 통신 구간, 즉, 대응 노드와 홈 에이전트간, 홈 에이전트와 모바일 라우터 간, 모바일 라우터와 모바일 노드간을 살펴보고 성능 향상을 꾀할 수 있는 구간을 분석하여, 해당 구간에 적합한 프로토콜을 제안한다.

• Journal of Communications and Networks
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• 제4권4호
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• pp.321-335
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• 2002

Emergence of the fourth generation mobile communication system (4G system) is now in its dawn. This article proposes a perspective framework on the 4G system, and discusses various kinds of system aspects and technological requirements in terms of novel service features, spectrum management, radio access technologies, wired access integration, core network, and mobile terminal. The focus of the article is to define the scope and features of the 4G system in an overall system/network viewpoint. From the foreseeable development trends, it is highly expected that whatever emerges in the 4G system will be some kind of constantly evolving and grand recursive concatenation of all the existing system/network developments.

• Journal of Information Processing Systems
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• 제9권2호
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• pp.247-258
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• 2013

A new secure network communication technique that has been designed for mobile wireless services, is presented in this paper. Its network services are mobile, distributed, seamless, and secure. We focus on the security of the scheme and achieve anonymity and reliability by using cryptographic techniques like blind signature and the electronic coin. The question we address in this paper is, "What is the best way to protect the privacy and anonymity of users of mobile wireless networks, especially in practical applications like e-commerce?" The new scheme is a flexible solution that answers this question. It efficiently protects user's privacy and anonymity in mobile wireless networks and supports various applications. It is employed to implement a secure e-auction as an example, in order to show its advantages in practical network applications.

• 한국정보통신학회논문지
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• 제2권1호
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• pp.109-116
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• 1998

본 논문은 DS-SS 이동 통신 시스템에서 복합 다계층 퍼셉트론 신경망을 이용한 간섭 신호 제어로써 직접순차 확산 스펙트럼의 협대역 간섭 신호를 역전파 학습 알고리즘을 이용하여 억압하고, 컴퓨터 시뮬레이션을 통해 동일 채널 간섭과 협대역 간섭의 실제 톤(Tone)에서 빠른 수렴 비율과 더 좋은 성능을 가지는 복소수 역전파 알고리즘으로부터 제안된 새로운 복합 (CBPRLS)알고리즘은 기존의 RAKE 수신기보다 더 낮은 비트 에러 율을 가지는 NNAC(Neural Network Adaptive Correlator)를 통해 간섭 신호가 보다 효율적으로 제어됨을 분석 고찰한다.

• IEIE Transactions on Smart Processing and Computing
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• 제3권5호
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• pp.325-330
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• 2014

The era of convergence is being applied to all areas of Information and Communication Technology (ICT). The convergence of broadcasting service and communication service almost occurs on smart devices including smartphone. The smart hybrid Digital Multimedia Broadcasting (DMB) is a typical example of the convergence of broadcasting and wireless communication service. The hybrid mobile broadcasting service can support seamless video, 3D, high quality, and additional data services based on network connection between the broadcasting and wireless network. The gateway and terminal (including apps on the smartphone) take the role of the main components on the hybrid service. This paper presents the service concept, main components structure, the implementation of gateway and terminals, and field test to the urban areas for the mobile hybrid system.

• 대한산업공학회지
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• 제29권4호
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• pp.292-303
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• 2003

An efficient mobility management for mobile stations plays an important role in mobile communication network. Two basic operations of mobility management are location registration and paging. A zone-based registration (ZBR) is implemented in most of mobile communication systems and we consider the mobility management scheme that combines a zone-based registration and a selective paging (SP). We propose new analytical model that can reflect on the characteristics of the ZBR based on 2-dimensional random walk mobility model and more efficient paging schemes considering the proposed model. We evaluate the performance of the mobility management scheme with our mobility model to determine the optimal size of location area that will result in the minimum signaling traffic on radio channels. Numerical results are provided to demonstrate that our mobility model is useful to evaluate the ZBR more exactly.