• Journal of information and communication convergence engineering
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• 제6권4호
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• pp.376-382
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• 2008

Developing highly cost-efficient and reliable embedded systems demands hardware/software co-design and co-simulation due to fast TTM and verification issues. So, it is essential that Platform-Based SoC design methodology be used for enhanced reusability. This paper addresses a reusable SoC platform based on OpenCores soft processor with reconfigurable architectures for hardware/software codesign methodology. The platform includes a OpenRISC microprocessor, some basic peripherals and WISHBONE bus and it uses the set of development environment including compiler, assembler, and debugger. The platform is very flexible due to easy configuration through a system configuration file and is reliable because all designed SoC and IPs are verified in the various test environments. Also the platform is prototyped using the Xilinx Spartan3 FPGA development board and is implemented to a single chip using the Magnachip cell library based on $0.18{\mu}m$ 1-poly 6-metal technology.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권3호
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• pp.191-193
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• 2005

This paper proposes a phase measurement algorithm which is based on the recursive implementation of sliding-DFT. The proposed algorithm is designed to have a robust behavior against the erroneous factors of frequency drift, additive noise, and twiddle factor approximation. Four channel power-line phase measurement system is also designed and implemented based on the time-multiplexed sharing architecture of the proposed algorithm. The proposed algorithm's features of phase measurement accuracy and its robustness against the finite wordlength effects can provide a significant impact especially for the ASIC or microprocessor based embedded system applications where the enhanced processing speed and implementation simplicity are crucial design considerations.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제6권2호
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• pp.173-186
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• 2000

실시간 내장 시스템은 운용 환경과 용도에 따라 멀티태스킹 커널이 지원해야 할 하드웨어 플랫폼과 자원 관리 정책이 다양하게 달라진다. 실시간 내장 시스템에 요구되는 크기와 성능 상의 제약 조건들을 엄격하게 만족해야 하는 멀티태스킹 커널을 새로운 시스템 서비스나 하드웨어에 맞게 개조하는 것은 쉽지 않다. 본 논문은 마이크로 프로세서 기반의 실시간 내장 멀티태스킹 커널의 구현에 재사용 가능한 객체지향 커널 프레임워크의 프로토타입을 객체 합성과 클래스 상속 메커니즘에 의거한 프레임워크 설계 패턴들을 적용하여 개발한 사례를 설명한다. 본 커널 프레임워크는 필요한 커널을 프레임워크의 개조와 확장을 통하여 효율적이고 일관성있게 생성할 수 있도록 하드웨어 환경과 시스템 자원 관리 정책에 의존적인 부분들이 프레임워크의 가변 부위(hot spot)로 분리된 추상 클래스들로 설계되어 있어서 높은 이식성과 개조성이 요구되는 마이크로 프로세서 기반 실시간 내장형 멀티태스킹 커널의 구현에 효과적으로 사용될 수 있다.

• 정보보호학회논문지
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• 제21권5호
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• pp.35-45
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• 2011

최근 유럽연합의 eSTREAM 공모사업에서 소프트웨어 분야에 선정된 Salsa20/12 알고리즘은 제한된 메모리의 8비트 MCU 상에서 AES보다 우수한 성능을 보여주는 스트림 암호이다. 또한 이론적 분석에 따르면 시차분석공격에 대한 취약성은 없으며, 전력분석 공격의 어려움에 대해서는 하위수준(low)로 평가되었으나, 현재까지 실제 전력분석 공격의 연구 결과가 발표된 바 없다. 따라서 본 논문에서는 소프트웨어 기반 Salsa20/12 에 대한 상관도 전력분석 공격 방법을 제안하고 실험을 통하여 검증하였다. 실험을 위해서 프로그래밍이 가능한 8비트 RISC 계열의 AVR 마이크로프로세서 (ATmega128L)를 장착한 실험보드에 전력분석 공격의 대응방법이 적용되지 않은 시스템을 구현하고, 해밍무게 모델을 적용한 전력분석 공격을 실시하였다.

• 제어로봇시스템학회논문지
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• 제8권12호
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• pp.1036-1040
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• 2002

To process data of digital linescan camera, the frame grabber is essential to handle the data in low-level and in high speed more than 30 MHz stably. Traditional approaches to the development of hardware in vision system for the special purpose are mai y based on PC system, and are expensive and gigantic. Therefore, there are many difficulties in applying those in the field. So we investigate, in this paper, the implementation of FPGA for real-time processing of digital linescan camera. The system is not based on PC, but electronic device such as micropncessor. So it is expected that the use of FPGAs for low-level processing represents a fast, stable and inexpensive system. The experiments are carried out on the web guiding system in order to show the efficiency of the new image processor.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1485-1488
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• 2003

This paper proposes a wireless EMG-based human-computer interface (HCI) for persons with disabilities. For the HCI, four interaction commands are defined by combining three elevation motions of shoulders such as left, right and both elevations. The motions are recognized by comparing EMG signals on the Levator scapulae muscles with double thresholds. A real-time EMG processing hardware is implemented for acquiring EMG signals and recognizing the motions. To achieve real-time processing, filters such as high- and low-pass filter and band-pass and -rejection filter, and a full rectifier and a mean absolute value circuit are embedded on a board with a high speed microprocessor. The recognized results are transferred to a wireless client system such as a mobile robot via a Bluetooth module. From experimental results using the implemented real-time EMG processing hardware, the proposed wireless EMG-based HCI is feasible for the disabled.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(1)
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• pp.35-38
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• 2004

In this paper, we aim to implement the embedded VoIP Phone based on EISC core Microcontroller. EISC is recently new microprocessor architecture, which contains both advantage of RISC and CISC. This advantages are desirably resulted in high code density, high performance and 16/32/64bit scalable instruction length. Also, we select the embedded system which can be guaranteed performance and economical efficiency for implementation that system. As the step of this research, we first study basic system for implementation of target system. Next, we construct the structure of embedded VoIP Phone based on 32bit EISC MCU efficiently. And then we realize that constructed system and verify the performance of that realized system by the test of voice communication in field.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.572-575
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• 2004

Since the 1990s, the advancement of semiconductor technology has resulted in the development of microprocessor technology, auxiliary computer technology, and application technology such as intelligent algorithms (neural network, fuzzy, etc.). These based the development of intelligent machines. An agent is autonomous software that recognizes environment, exchanges knowledge with other agents and makes decisions. We designed agent-based sensor structure. For the purpose, first, it modeled the function of an intelligent machine. Second, it designed sensory function on the agent level.

• 대한전기학회논문지
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• 제40권8호
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• pp.774-781
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• 1991

This paper proposes an auto-tuning method of a discrete -PIC controllers which is based on the Ziegler and Nichols's PID Tuning Rule. This tunign rule is derived using the Pade's first order approximation and it prevents the performance degradation caused by the time-delay effect of zero order holder when the Ziegler-Nichols tuning rule is applied to a discrete PID controller. A simple and practical auto-tuning method is proposed through combining this discrete tuning rule with the relay control. The auto-tuning scheme is implemented on a microprocessor based system and is applied to a position control system to show the effectiveness of the discrete tuning rule.

• 제어로봇시스템학회논문지
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• 제12권7호
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• pp.637-643
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• 2006

Generally, the tracking performance of optical disk drive(ODD) system can be improved using a disturbance observer(DOB). However, a DOB is not easily applied in an ODD system because an additional microprocessor, such as a digital signal processor(DSP), is needed. This paper shows how a DOB system can be replaced by the error-based modified disturbance observer(EM-DOB) when two mathematical conditions are satisfied. Due to the simplified structure of EM-DOB, the algorithm is easily implemented as an analog circuit, which is suitable for the ODD servo system. Additionally, in these algorithms, disturbances rejection performances can be tuned as Q filter parameters. Similar to a DOB system, three design guidelines of a Q filter can be applied. Experimental results of DOB and EM-DOB are evaluated under forced disturbances.