• 전자통신동향분석
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• 제35권2호
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• pp.38-49
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• 2020

In recent years, the unmanned aerial vehicle (UAV) assisted mobile free space optical (FSO) communication technique has attracted considerable attention regarding its aims to provide improved communication conditions for fixed-to-fixed FSO network and promising fronthaul and backhaul solutions for 5G+ wireless networks. This can be attributed to its outstanding advantages such as fast deployment and flexible network configuration. The UAV-assisted mobile FSO system can be used to provide cost-effective internet services in rural and remote areas and in hotspot areas that are characterized by increased data traffic. Additionally, it can be used to provide secure communication services under emergency circumstances. In this report, we review recent R&D trends in wireless network technology employing the UAV-assisted mobile FSO technique and key technologies for mobile FSO wireless networks. Furthermore, we introduce drone-based mobile FSO terminals and control systems that we have developed.

• 전자공학회논문지CI
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• 제47권6호
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• pp.93-102
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• 2010

기존의 웹 기반 정보 서비스 시스템은 실시간 정보제공과 응급상황에 대한 원격 지원 조치가 어렵다는 문제점들을 갖는다. 이러한 문제를 해결하기 위해서, 본 논문에서는 모바일 통신기기(휴대폰, PDA, Smart Phone, Webpad)를 이용하여 원격시스템을 관리 및 모니터링하고 실시간으로 원격지의 시스템을 제어할 수 있는 실시간 무선 원격제어 시스템을 설계 및 구현하였다. 제안하는 시스템은 원격지 예를 들어 '사무 빌딩'과 보육시설 예를 들면 '유치원'에 적용하였다. 사무 빌딩에 구현한 경우는 유선(웹 환경) 또는 무선(모바일 장비)을 통해서 건물관리 및 시스템 환경에 설치된 각종 센서정보를 실시간으로 관리 와 제어할 수 있다. 유치원 시스템에 적용한 경우는 유치원 아동의 활동을 인증된 사용자의 핸드폰으로 실시간 모니터링 할 수 있는 서비스가 제공된다. 제안한 시스템의 보안기능은 모바일장비 사용자 인증과 대상 시스템 접근제어 기능을 갖는다. 제안하는 시스템은 실시간 사용자 인증 기능과 시스템 접근제어기능을 실행하도록 하여 자원관리자와 모바일 장비 사용자의 안전성을 높이고, 중단 없는 서비스의 제공뿐만 아니라 실시간 모바일 서비스 환경을 제공한다.

• 정보처리학회논문지D
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• 제12D권4호
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• pp.521-530
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• 2005

무선 네트워크(Wireless Network)의 약한 연결성 및 접속단절, 모바일 클라이언트의 이동성, 모바일 클라이언트의 휴대성으로 인해 발생하는 모바일 데이터베이스 시스템(Mobile Database System) 관련 이슈들과 이 문제들을 해결하기 위한 연구들도 한창이다 이동 컴퓨팅은 언제 어디서나 원하는 모든 정보를 이용할 수 있는 사용자의 편의성이나 성능 면에서의 요구를 만족시키고 있지만, 데이터 관리 측면에서는 해결되어야만 하는 많은 문제점들을 안고 있다. 본 논문은 모바일 클라이언트-서버(Mobile Client-Server) 환경에서 모바일 데이터베이스 시스템 특성상 가질 수 있는 무선 네트워크의 약한 연결성 및 접속성 단절로 인한 데이터베이스 비축(Database Hoarding)과 관련된 문제, 공유 데이터(Shared Data)의 일관성(Consistency)유지 문제, 그리고 로그(Log) 최적화 문제를 해결하기 위한 모바일 질의 처리 시스템(MQPS : Mobile Query Processing System)을 설계하는데 목적이 있다. 또한, MQPS의 효율성 증명을 위해 C-I-S(Client-Intercept-Server) 모델과의 성능비교를 통해 제안한 시스템이 우수하다는 것을 입증하였다.

• 한국전자파학회지:전자파기술
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• 제12권3호
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• pp.49-59
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• 2001

Wireless communication systems will be one of the biggest drivers of semiconductor products over the next decade. Global Positioning System (GPS) and Blue-tooth, HomeRF, and Wireless-LNA system are just a few of RF-module candidate awaiting integration into next generation mobile phone. Motivated by the growing needs for lowcost and multi-band/multi-function single chip wireless transceivers, CMOS technology has been recognized as a most promising candidate for the implementation of the future wireless communication systems. This paper presents recent developments in RF CMOS technology so far, much of them have been developed in ETRI, and from them forecasts technology trends in the near future.

• 전자공학회지
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• 제29권9호
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• pp.1020-1020
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• 2002

Wireless communication systems will be one of the biggest drivers of semiconductor products over the next decade. Global Positioning System (GPS) and Blue-tooth, HomeRF, and Wireless-LNA system are just a few of RF-module candidate awaiting integration into next generation mobile phone. Motivated by the growing needs for low-cost and multi-band/multi-function single chip wireless transceivers, CMOS technology has been recognized as a most promising candidate for the implementation of the future wireless communication systems. This paper presents recent developments in RF CMOS technology, which is classified into device technology and circuit technology and from them forecasts technology trends in the near future.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅲ
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• pp.1589-1592
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• 2003

Existing system management software solutions show limitations in time and space, as well as problems such as uncertain error messages, and also difficulty providing swift assistance or real time emergency support. Therefore, a wireless remote control system has been designed and implemented in this thesis, which is capable of managing and monitoring remote systems using mobile communication devices (Mobile Phone, PDA, Smart Phone, Webpad) for instantaneous control. The implemented real time wireless remote control system provides remote server management functions, error or event message (unctions, log record functions, authentication function via mobile devices.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.116.4-116
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• 2002

$\textbullet$In case of using overhead camera system, mobile robot moves under static working area. $\textbullet$Mobile robot must use onboard camera system to work under wide working area. $\textbullet$Mobile robot must have wireless LAN to remove restriction of movement. $\textbullet$Onboard camera system must have wireless LAN environment. $\textbullet$We develop embedded vision platform using onboard camera.

• 제어로봇시스템학회논문지
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• 제17권7호
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• pp.720-729
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• 2011

The demand for wireless technology in home automation systems has recently been increasing due to several advantages such as installation cost reduction, easy placement, easy extension, aesthetic benefits, and mobile device connectivity. Among the many wireless technologies, ZigBee is one of the most useful for home automation; a wireless home networking system can be configured using ZigBee alone. Compatibility with conventional home networking systems that are based on wired media, however, is not supported. KNX is a mature protocol for wired media that is recognized as an international standard. This paper proposes a KNX-ZigBee gateway to interface between KNX and ZigBee systems and thereby enable integration of wired and wireless home automation systems.

• 대한원격탐사학회지
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• 제19권1호
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• pp.81-89
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• 2003

A provision of spatial information is expected to make a market explosion in various fields. A distribution of spatial data on wireless mobile environments indicates a huge expansion of mobile technology as well as a spread of geospatial applications. For high-qualified spatial information, the 4S technology Project that is integrating four kinds of spatial systems is currently being executed with the goal of nationwide integration of spatial data and spatial information systems. In terms of network environments, a mobile ad hoc network where mobile terminals communicate with each other without any infrastructures has been standardized for the next generation mobile wireless network. With respect to the future technologies for spatial information, it is necessary to design 4S applications on mobile ad hoc networks. This paper addresses the issue, which is proposing design concepts for distributing 4S spatial data on mobile ad hoc networks and for ad hoc styled 4S applications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제2권2호
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• pp.103-119
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• 2008

Traditional web-based services that require users to browse via documents and fill out forms, are difficult to use with mobile devices. Moreover, as the web paradigm assumes active clients, further complications are introduced in cases where the server is the active entity, instead of the client. This paper presents a Server-Centric Interaction Architecture (SCIA) for wireless applications. The architecture enables servers to initiate communication with clients as well as push secure targeted data to them, in a piecemeal fashion. It further enables the development of highly collaborative wireless services with interactive user interfaces.