• 대한임베디드공학회논문지
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• 제2권1호
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• pp.31-42
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• 2007

A transform coding scheme for the transmission of audio data in ZigBee based wireless personal area networks (WPAN) is presented in this paper. Here, wavelet transform is exploited to encode the features of audio data included mainly in the low frequency region. As a result, it is confirmed that the presented scheme recovers the original audio signals much accurately while it transmits the binary data compressed as 37.5% of the entire data generated without coding scheme. Especially, the mean-squared error between the recovered and original audio data approaches $10^{-4}$ when the signal-to-noise power ratio is sufficiently high. Hence, the presented coding scheme which exploits the wavelet transform is possibly applied for high-quality audio data transmission services in a small-scale sensor network based on ZigBee. Such a result is considered to be applicable as a basic material to update the technical specifications and develop the applications of ZigBee in WPANs.

• 한국정밀공학회지
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• 제21권10호
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• pp.86-93
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• 2004

This paper presents the remote measurement of the ECU signals adopted with KWP 2000 protocol using the wireless communication technique of bluetooth. The bluetooth technology will be the most promising network paradigm which can open the new area in the information technology. Especially, bluetooth module is able to link all the electrical products and personal computers to cellular phone or PDA. This research has a try to design a wireless measurement model of ECU signal based on the car telemery system using bluetooth device. In order to measure the ECU signals, we designed the interface circuits which is able to communicate between the ECU system and the terminal circuits according to the ISO, SAE regulation of communication protocol standard. A microprocessor S3c341 OX is used for the system control and communication of ECU signals. The embedded system software is programmed to measure the ECU signals using the ARM compiler and ANCI C based on Micro/OS-II kernel to communicate between two bluetooth modules using bluetooth stack. The remote measurement of ECU signals using the bluetooth was designed and implemented to evaluate the performance of wireless network to the transmit measurement data. The possibility for the remote measurement of the self diagnosis signals of ECU adopted with KWP2000 protocol verified through the developed systems and algorithms in embedded system.

• 정보보호학회논문지
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• 제14권3호
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• pp.125-135
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• 2004

IEEE 802.15.3 High Rate WPAN(Wireless Personal Area Network, 이하 HR-WPAN)은 홈네트워크와 같은 개민 용도의 장치들 사이의 빠른 무선 연결을 지원하기 위해 연구되어 왔다. 장치들의 안전한 사용을 위한 보안 요구에 따라 MAC 계층에서의 대칭키 암호 시스템을 채택하고 있지만, 키를 안전하게 교환하는 방법에 대해서는 언급하고 있지않다. 또한 앞으로 도래할 유비쿼터스(Ubiquitous) 컴퓨팅 환경의 핵심 기반 기술이 된다는 점에서 하나의 Piconet으로만 구성된 단순한 토폴로지를 벗어나 Child Piconet이 복잡하게 연결된 토폴로지 상에서 같은 Piconet에 속하지 않는 DEV들 간의 Secure Relationship을 맺는 과정에 대한 연구도 필요하다. 따라서 이 논문에서는 공개키 기반 구조를 사용하여 안전한 키 교환을 통한 Secure Membership을 맺는 과정을 연구하였으며, 또한 Child Piconet이 복잡하게 연결된 토폴로지에서 DEV들 간의 Secure Relationship을 맺기 위하여 공개키 기반 구조에 계층 구조를 추가한 프로토콜을 제안하였다.

• 조명전기설비학회논문지
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• 제22권11호
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• pp.44-47
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• 2008

New Eight-phase Preferred Pairs (EPPs) that have Zero-Correlation Duration (ZCD) of (0.5N+1) chips are constructed for the periods of $N=4{\times}2n$ (n=1,2,3...). By using the chip-shift operation of the EPP, new eight-phase ZCD sequences are constructed in this paper. We certified its ZCD property by various correlation simulations. This new eight-phase spreading sequence can be used for Interference cancelled wireless personal area network(WPAN) based on approximately synchronized code-division-multiple-access(AS-CDMA) system.

• Journal of Power Electronics
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• 제13권2호
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• pp.313-321
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• 2013

This paper describes the operation analysis results of a communication-based DC micro-grid using a hardware simulator developed in the lab. The developed hardware simulator is composed of distributed generation devices such as wind power, photovoltaic power and fuel cells, and energy storage devices such as super-capacitors and batteries. Whole system monitoring and control was implemented using a personal computer. The power management scheme was implemented in a main controller based on a TMS320F28335 chip. The main controller is connected with the local controller in each of the distributed generator and energy storage devices through the communication link based on a CAN or an IEC61850. The operation analysis results using the developed hardware simulator confirm the ability of the DC micro-grid to supply the electric power to end users.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2418-2423
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• 2003

Bluetooth is a low cost, license-free, and short-range radio communication technology. This gradually gaining de facto standard for applications of a personal area network over the world. To make it further popular, it should provide faster and more flexible connectivity than that supported by the existing bluetooth specification. This paper proposes a new Ad hoc scatternet formation algorithm that supports those connectivity under circumstances such that devices can not get in direct touch with one another; say out-of-bounded case. It also maintains the character that those connectivity minimizes the number of piconets when all devices are in the communication range with one another, say in-bounded case, as pervious works.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.57-60
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• 2000

본 논문은 블루투스 헤드셋의 구현에 대해 기술한다. 블루투스 헤드셋은 ACL 연결을 통하여 헤드셋과 오디오 게이트웨이 사이의 link를 선정하고, SCO 연결을 통하여 64kbps의 음성을 전송한다. 본 논문에서 구현한 블루투스 헤드셋은 HCI가 없는 구조로 설계되어 블루투스 모듈내에 모든 프로토콜 스택이 구현되었고, 헤드셋에 구현된 상위 프로토콜 및 응용 프로그램에 대해서 Unix 환경에서 C-language modeling을 통하여 검증하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(1)
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• pp.107-110
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• 2004

IEEE 802.15.3 is wireless Medium Access Control(MAC) and Physical Layer(PHY) specification for high rate WPAN (Wireless Personal Area Network). IEEE 802.15.3 MAC Layer provides Qos with three kinds of acknowledgements; No acknowledgement, Immediate acknowledgement, and Delayed acknowledgement. This paper presents how to improve QoS with new acknowledgement method called Delayed Negative acknowledgement. This paper describes the method of using Delayed Negative acknowledgement and presents the calculation of QoS improvement by using Delayed Negative acknowledgement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.435-437
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• 2004

In this paper, we aim to design and implement supporting IPv6 Bluetooth Access point(AP) in Linux. Bluetooth is a cable replacement technology designed for short range ad-hoc connections, which most likely change the way we handle and access information in the near future. In Personal Area Network(PAN) mobile devices need many IP address space, then we need next generation Internet Protocol(IPv6). We designed Bluetooth Access Point with Bluetooth stack and MAC bridge function in Linux. The implementation tested on Linux system based on Bluetooth Access Point with other Bluetooth devices.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.945-948
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• 2005

Mobile computing devices are becoming increasingly prevalent in a huge range of physical area, offering a considerable market opportunity. The focus of this paper is on the development of a platform of fault diagnosis system integrating with personal digital assistant (PDA). An improvement of induction machine rotor fault diagnosis based on AI algorithms approach is presented. This network system consists of two parts; condition monitoring and fault diagnosis by using Artificial Intelligence algorithm. LabVIEW allows easy interaction between acquisition instrumentation and operators. Also it can easily integrate AI algorithm. This paper presents a development environment fur intelligent application for PDA. The introduced configuration is a LabVIEW application in PDA module toolkit which is LabVIEW software.