• 정보처리학회논문지C
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• 제10C권2호
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• pp.209-216
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• 2003

최근 무선 인터넷 서비스에 대한 관심이 고조되면서 관련 기술 개발이 활발히 진행되고 있다. 현재 가장 유력한 국제표준 중 하나로 인식되어 가고 있는 WAP(Wireless Application Protocol)의 규격에 따르면 이동 단말과 WAP 서버는 WAP 게이트웨이를 통하여 통신하도록 되어있다. 본 논문은 리눅스 기반에서 WAP 게이트웨이와 서버가 통합적으로 지원되는 I(Intelligent) WAP 게이트웨이/서버 플랫폼의 설계 및 구현에 관한 것이다. 제안된 WAP 플랫폼은 WAP 게이트웨이, JAVA기반의 서버 개발 환경, WML 툴킷 및 MUI(Management User Interface) 등 크게 4개의 모듈로 구성되고, 베어러(bearer)망으로 SMSC(Short Message Service Center)와 CSD(Circuit Switched Data) 라우터를 고려하였다.

• 한국IT서비스학회지
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• 제11권2호
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• pp.291-306
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• 2012

Recently, Wireless Mesh Network (WMN) technology recently has been used in various industries. Especially, a number of multi-channel assignment schemes have been presented to improve the throughput of IEEE 802.11-based multi-hop WMN. However, performance of the conventional multi-channel assignment schemes is not enough to satisfy the industry requirements. We, thus, should study more about the multi-channel assignment scheme in order to enhance the performance. This paper proposes a novel channel assignment scheme that employs Multi-channel and Multi-Interface in the WMN. The proposed scheme can obtain the traffic information of the network and the efficient channel assignment result without any message exchanges. We verify the efficiency of the proposed scheme through the mathematical modeling and the real-world experiments. The results show that the proposed scheme improves the throughput of the network compared with the conventional schemes.

• Journal of Communications and Networks
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• 제2권1호
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• pp.35-45
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• 2000

this paper presents the concept of "mobile ATM', a proposal for third-generation (3G) mobile communication network infrastructure capable of supporting flexible evolution of radio technologies from today's cellular and data services towards future wireless multimedia services. Mobile ATM provides generic mobility management and QoS-based transport capabilities suitable for integration of multiple radio access technologies including cellular voice. wireless data, and future broadband wireless services. The architecture of a mobile ATM network is outlined in terms of the newly-defined "W-UNI" interface at the radio link and "M-UNI"and "M-UNI" interface which supports unified access for WATM and non-ATM mobile terminals through corresponding interworking functions (IWF) is explained. leading to an understanding of how different radio access technologies are supported by the same ATM-based core network infrastructure. Generic mechanisms for handoff and location management within the core mobile network are discussed. and related protocol extensions over the "W-UNI" and "M-UNI/NNI"interfaces are proposed. the issue of "crossover switch (COS)" selection in mobile ATM is considered, and a unified handoff signaling syntax which supports flexibility in COS selection is described. Typical signaling sequences for call connection and handoff using the proposed protocols are outlined. Experimental results form a proof-of-concept mobile ATM network prototype are presented in conclusion.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1067-1070
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• 2003

In this paper, we present a remote measurement system for the wireless monitoring of ECU Sensor Signals of vehicle. In order to measure the ECU sensor signals, the interface circuit is designed to communicate ECU and designed terminal wirelessly according to the ISO, SAE regulation of communication protocol standard. A micro-controller 80C196KC is used for communicating ECU sensor signals. ECU sensor signals are transmitted to the RF-wireless terminal that was developed using the micro controller 80386EX. LCD, and RF-module. 80386EX software is programmed to monitor the ECU sensor signals using the Borland C++ compiler in which the half duplex method was used for the RS232 communication. The algorithms for measuring the ECU sensor signals are verified to monitor ECU state. At the same time, the information to fix the vehicle's problem can be shown on the developed monitoring software. The possibility for remote measurement of ECU sensor signals using 80386EX is also verified through the developed systems and algorithms.

• 한국인터넷방송통신학회논문지
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• 제11권5호
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• pp.1-9
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• 2011

오늘날에는 모바일 스마트 기기를 많이 사용해본 소비자들이 무선 연결 방식과 같은 보다 편리하고 스마트한 가정용 전자기기의 연결성을 기대하고 있기 때문에 기존의 전기선을 다른 지능적인 연결방법으로 대체하는 것이 필요하다. 이 연구에서는 양방향 CEC 제어 구조를 새롭게 제안하여 밀리미터 밴드 이미지 전송 시스템에서 제어능력을 단방향에서 양방향으로 확장하는 것을 목적으로 하는데, 이는 2자유도 제어 능력이 HDMI 인터페이스 시스템에서 보다 지능적인 편리성을 제공하기 때문이다. 실험연구를 통해 1080p 풀 HD 이미지 스트림에 대해서 3.0 Gbps의 전송 성능 결과를 보여 지능적 2 DOF CEC 인터페이스를 보유한 밀리미터 밴드의 진보된 이미지 전송 솔루션으로서 제안된 시스템의 유용성을 보인다.

• 디지털융복합연구
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• 제11권9호
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• pp.195-200
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• 2013

영상 보안 시스템에서 유기물은 공공장소에서 의도적으로 버려진 물건으로서 카메라 개수가 많아지는 환경에서 지능적 시스템을 통해 자동적으로 검지되어야 한다. 이 연구에서는 이러한 유기물을 자동적으로 감지하여 그 영상 정보를 저장할 수 있는 고해상도 영상의 무선 인터페이스가 가능한 스마트 보안 디스크 시스템의 설계 방식을 다룬다. 연구에서 제안된 설계 시스템을 실제로 구현하여 고해상도 영상을 압축하지 않은 채 초당 60 프레임 전송이 가능함을 확인하였고, 이를 RAID 구성의 디스크 시스템에 저장할 수 있음을 보였다. 또한 제안된 영상 보안 소프트웨어는 PAT 성능지수에서 80%의 우수한 검지율을 보인다.

• 제어로봇시스템학회논문지
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• 제10권5호
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• pp.434-441
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• 2004

In this paper, an exoskeleton-type motion capturing system is designed and implemented. The device is designed to have 12 degree-of-freedom entirely to represent human arm motions. Forward and inverse kinematics of the device are analyzed to make sure of its singular positions. With the designed model parameters, simulation studies are conducted to verify that the designed motion capturing system is effective to represent human motions within the workspace. As a counterpart of the exoskeleton system, a mobile robot is built to follow human motion restrictively. Experimental studies of teleoperation from the exoskeleton device to control the mobile robot are carried out to show feasible application of wireless man-machine interface.

• 센서학회지
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• 제16권2호
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• pp.110-114
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• 2007

In this paper we present 3-D Navigation View, a three-dimensional visualization of indoor environment which serves as an intuitive and unified user interface for our developed indoor location tracking system via Virtual Reality Modeling Language (VRML) in web environment. The extracted user's spatial information from indoor location tracking system was further processed to facilitate the location indication in virtual 3-D indoor environment based on his location in physical world. External Authoring Interface (EAI) provided by VRML enables the integration of interactive 3-D graphics into web and direct communication with the encapsulated Java applet to update position and viewpoint of user periodically in 3-D indoor environment. As any web browser with VRML viewer plug-in is able to run the platform independent 3-D Navigation View, specialized and expensive hardware or software can be disregarded.

• 한국IT서비스학회지
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• 제10권2호
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• pp.271-279
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• 2011

This paper draws performance results through comparing WMNs' methods when the WMNs are used in tunnel construction sites. There are many advantages of WMNs : lower cost, easy to network maintenance, robustness and reliability within RF-ranges. As a result, using the WMNs would be suitable to employ as a network infrastructure for the construction sites. This paper evaluates the performance of WMNs which we have installed in a tunnel construction. Through the performance results, we conclude the performance of data throughputs gets lower when we perform the network in tunnel environments. We make attempts WMNs' two major methods which are SISC(Single Interface with Single Channel) and MIMC(Multi Interface with Multi Channel) to figure out which method will be better for the construction sites. Through the experiments, the WMN based on the MIMC method was comparatively suitable in network performance aspect for the tunnel Sites.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.1308-1311
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• 2002

We present a low-power MPEG-4 video codec chip capable of delivering high-quality video data in wireless multimedia applications. The discussion will focus on the architectural design techniques for implementing a high-performance video compression/decompression chip at low power architectures. The proposed MPEG-4 video codec can perform 30 frames/s of QCIF or 7.5 frame/s of CIF at 27MHz for 128k∼144kbps. By introducing the efficiently optimized Frame Memory Interface architecture, low power motion estimation and embedded ARM microprocessor and AMBA interface, the proposed MPEG-4 video codec has low power consumption for wireless multimedia applications such as IMT-2000.