• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.676-678
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• 2003

Recently, in according as rapid improvement of telecommunication markets and wireless internet technology, Location- Based Services (LBS) have been discussed as new 'Killer' application. The purpose of LBS is to determine location of user through mobile handset and to offer location information service to end-user. This paper has suggested an efficient transmission scheme of maps data as one of the important content services relating to data transmission of LBS in mobile environment. The basic system consists of three parts : (1) GIS (Geographic Information System) Server for storing, processing and handling map data, (2) Middleware Server for transmitting of map data by request of client, and (3) Client for requesting map data to Server and displaying them on handset. Also, in order to transmit map data, we are to expand WKB (Well Known Binary) in conformance to Simple Feature Specification of OGC (Open GIS Consortium), and increase efficiency of data transmission by developing trans mission data format to be able to transmit lightweight data and considering data compression technology.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.33-35
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• 2006

We studied the prototypal developments of Plastic Cortex Stimulator (PCS) for stroke patients. The PC sends the stimulation parameters (amplitude, pulse width, cycle, etc.) to the transmitter ZigBee module through serial port. The receiver ZigBee module generates stimulation waveform. The generated output can be controlled by the PC program. Further study can be expanded to portable handset such as PDA using ZigBee. The wireless control of PCS with the handset can help the tele-rehabilitation.

• 대한임베디드공학회논문지
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• 제3권1호
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• pp.30-33
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• 2008

This paper persents how to port HAL (Handset Abstraction Layer) on embedded Linux to support WIPI (Wireless Internet Platform for Interoperability). As smart phones are widespread nowdays, the operating system is changing from a simple kernel like Qualcomm REX OS to more feature-rich Linux kernel. For this reason, we investigate the internal structure of HAL on REX OS and design how to port it to embedded Linux. Careful analysis leads us to identify several porting issues such as thread support, graphical user interface. In addition, we describe some problems discovered during the implementation process and propose alternative architecture of HAL for WIPI on Linux.

• 한국멀티미디어학회논문지
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• 제10권10호
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• pp.1338-1346
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• 2007

모바일 단말기의 성능과 해상도가 발전함에 따라 모바일 단말기는 단순히 음성통신 장치가 아닌 다양한 서비스를 제공하는 도구로 인식되기에 이르게 되었다. 또한 인간과 기계간의 사용자 인터페이스의 진보로 인하여 전자장치와 임베디드 시스템 기술에 기반한 차량의 진단과 관리 기술이 출현하고 있다. 본 논문에서는 모바일 단말기에서 OBD-II(On Board Diagnostics version II) 프로토콜을 이용하여 자동차를 진단하는 기능에 대하여 설명하고자 한다. 2005년 이후 국내에 출시되는 모든 자동차에는 진단 시스템 표준인 OBD-II 시스템 장착이 의무화되었다. 본 연구에서는 이러한 배경을 바탕으로 OBD-II표준을 기반으로 한 프로토콜 변환기와 개인소지 휴대폰만으로 자동차의 진단이 가능한 자동차 자기진단시스템을 개발하게 되었으며, 여기에 필요한 사용자 인터페이스는 모바일 표준 플랫폼인 WIPI에서 구현하였다.

• Asia Marketing Journal
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• 제15권3호
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• pp.1-14
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• 2013

Our research brings managerial insights for developing new digital convergence of devices and services. To explain the phenomenon of device and service convergence, we combine two different approaches from separate research fields: a perceptual mapping technique generally used for segmentation in marketing and associative network analysis mobilized to understanding network structure of core and peripheral as well as the information mediating role of nodes in network science. By combining these two approaches, we provide an in-depth analysis of the associations among devices and services by assessing the centrality of device and service nodes in an associative network. This is done by examining the connections between these services and devices as well as investigating the role of mediation in the combined device-service associative network. Our results based on bi-partite network analysis of survey responses from 250 Internet Protocol (IP) television viewers show which device and which service will play the major role in future device and service convergence as well as which characteristics and functionalities have to be incorporated into future convergence. Among the devices, the mobile handset with the betweenness centrality of 0.26 appears to be the device that would lead future device convergence. Among the services, wireless broadband with the betweenness centrality of 0.276 appears to be the service on which future service convergence needs to be developed. This result is quite unexpected, since wireless broadband has a lower penetration rate than other services, such as fixed broadband and cable TV. In addition, we indicate the possibility of converging devices, such as personal digital assistant (PDA) and mobile handset, and services, such as IPTV and mobile Internet, into wireless broadband services in the future.

• Journal of electromagnetic engineering and science
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• 제5권3호
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• pp.132-139
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• 2005

Wireless bio-signal sensing system, which is based on the principle of Doppler radar, can measure a respiration and heart rates with a periodic movement of skin and muscle near the heart. Though the sensing monostatic system using a circulator has been studied, this bistatic system can be improved by using a circular polarized antenna which has a high isolation between transmitter and receiver. In this paper, we measured the bio-signal without the direct contact with the person. The design of each system and experimental results are discussed.

• 한국멀티미디어학회논문지
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• 제8권6호
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• pp.836-843
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• 2005

The Wireless Internet services widely spread out with the developments of CDMA(Code Division Multiple Access) networks and wireless units. In contrast to the telecommunication network, WPAN (Wireless Personal Area Network) enables to transmit data and voice in personal area. Although WPAN technologies are commercially utilized, the combined services with COMA network are not so poplar up to now. Various services can be provided using the combination between COMA and WPAN. This paper presents the practical and united model between COMA and WPAN. Specially, the main focus of this research lies on the design of the Middle-ware system of a handset which could be managing both COMA and WPAN. This system used Bluethooth by WPAN. For the devices with the proposed WPAN Middle-ware, service areas of the COMA network can be expanded to WPAN, various services can be realized by the transmission of data and voice, and consequently, the user computing environment could be improved.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.346-349
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• 2005

본 논문은 무선통신용 휴대단말기를 설계하는데 있어 인체 전자파 흡수율(SAR)을 저감시키는 방법을 제안한다. 단말기의 안테나로부터 방사되는 전자파에너지는 휴대단말기 기구의 특정부분에 밀집되는데 이와 같은 전계강도는 인체의 두부에 영향을 미쳐 SAR값의 증가 요소로 작용한다. 이를 감소시키는 방법으로는 표면전계가 밀집되지 않는 구조의 기구 설계법을 제시한다. 안테나를 포함한 단말기의 해석은 유한요소법(FEM)을 사용하였으며, 본 저감법를 적용한 경우 SAR첨두치의 약50 %를 저감하는 효과가 나타났다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.854-859
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• 2002

Location Based Services, or LBS refers to value-added service by processing information utilizing mobile user location. With the rapidly increasing wireless internet subscribers and world LBS market, the various location based applications are introduced such as buddy finder, proximity and security services. As the killer application of the wireless internet, the LBS has preconsidered technology about location determination technology, LBS middleware server for various application, and diverse contents processing technology. This paper describes the open architecture for LBS platform ensuring interoperability among the wireless networks and various location-based application services and the functional requirements for the LBS platform. The LBS platform in a narrow sense provides a standard interfaces for location management and network management for location services as follows, positioning (location acquisition through network or/and handset), location managing, location based functions, profile management, authentication and security, location based billing, information roaming between carriers and the system monitoring independent to specific network or ISP/CPs(Content Providers).

• 한국통신학회논문지
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• 제33권4A호
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• pp.387-393
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• 2008

본 논문에서는 TDD HSDPA(Time Division Duplex High Speed Downlink Packet Access)와 WiBro(Wireless Broadband Portable Internet) 와 같은 이동통신 규격을 지원하는 SDR(Software Defined Radio) 단말 모뎀 플랫폼을 제안한다. 제안하는 SDR 플랫폼은 DSP, FPGA, 마이크로프로세서 등 프로그래밍 가능한 소자들을 채용하여 HSDPA와 WiBro와 같은 기능을 담당하는 프로그램 등이 하드웨어 플랫폼 상에 다운로드 가능하도록 하였다. 제안하는 플랫폼은 이동통신네트워크의 멀티모드 단말시스템을 위한 물리계층 규격의 기능검증 등에 사용될 수 있다. 본 논문은 먼저 HSDPA와 WiBro 시스템의 물리계층 수신구조를 설명하고, 제안하는 SDR 플랫폼의 하드웨어 구현 방법과 각 모드에 요구되는 기능과 구현한 하드웨어 플랫폼 상에서의 최적화된 신호 흐름의 설계방법을 제시한다. 마지막으로 테스트신호를 이용한 루프백(loopback) 테스트를 통하여 제안한 SDR 플랫폼 상에 동작하는 각 모드 별 링크 성능을 보여준다. 제시된 실험 성능은 컴퓨터 시뮬레이션 성능과 비교하였다.