• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.1
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• pp.64-72
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• 2013

Recently, stream cipher Rabbit was selected for the final eSTREAM portfolio organized by EU ECRYPT and as one of algorithm in part of ISO/IEC 18033-4 Stream Ciphers on ISO Security Standardization. However, a feasibility of practical power analysis attack to algorithm in experiment was introduced. Therefore, we propose appropriate methods such as random masking and hiding schemes to secure against power analysis attack on stream cipher Rabbit. We implement the proposed method with increment of 24% operating time and 12.3% memory requirements due to maintaining a high-speed performance. We use a 8-bit RISC AVR microprocessor (ATmegal128L chip) to implement our method for practical experiments, and verify that stream cipher Rabbit with our method is secure against power analysis attack.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.3
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• pp.27-35
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• 2011

Design of Sensor nodes in Wireless Sensor Network(WSN) should be considered some properties as electricity consumption, transmission speed, range, etc., and also be needed the protection against various attacks (e.g., eavesdropping, hacking, leakage of customer's secret data, and denial of services). The stream cipher Rabbit, selected for the final eSTREAM portfolio organized by EU ECRYPT and selected as algorithm in part of ISO/IEC 18033-4 Stream Ciphers on ISO Security Standardization recently, is a high speed stream cipher suitable for WSN. Since the stream cipher Rabbit was evaluated the complexity of side-channel analysis attack as 'Medium' in a theoretical approach, thus the method of power analysis attack to the stream cipher Rabbit and the verification of our method by practical experiments were described in this paper. We implemented the stream cipher Rabbit without countermeasures of power analysis attack on IEEE 802.15.4/ZigBee board with 8-bit RISC AVR microprocessor ATmega128L chip, and performed the experiments of power analysis based on difference of means and template using a Hamming weight model.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.5
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• pp.35-45
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• 2011

The Salsa20/12 stream cipher selected for the final eSTREAM portfolio has a better performance than software implementation of AES using an 8-bit microprocessor with restricted memory space, In the theoretical approach, the evaluation of exploitable timing vulnerability was 'none' and the complexity of side-channel analysis was 'low', but there is no literature of the practical result of power analysis attack. Thus we propose the correlation power analysis attack method and prove the feasibility of our proposed method by practical experiments, We used an 8-bit RISC AVR microprocessor (ATmegal128L chip) to implement Salsa20/12 stream cipher without any countermeasures, and performed the experiments of power analysis based on Hamming weight model.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.6
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• pp.539-546
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• 2006

The Air Quality Sensor(AQS), located near the fresh air inlet, serves to reduce the amount of pollution entering the vehicle cabin through the HVAC(heating, ventilating, and air conditioning) system by sending a signal to close the fresh air inlet door/ventilation flap when the vehicle enters a high pollution area. The sensor module which includes two independent sensing elements for responding to diesel and gasoline exhaust gases, and temperature sensor and humidity sensor was designed for intelligent AQS in automobile. With this sensor module, AVR microcontroller was designed with back propagation neural network to a powerful gas/vapor pattern recognition when the motor vehicles pass a pollution area. Momentum back propagation algorithm was used in this study instead of normal backpropagation to reduce the teaming time of neural network. The signal from neural network was modified to control the inlet of automobile and display the result or alarm the situation in this study. One chip microcontroller, ATmega 128L(ATmega Ltd., USA) was used for the control and display. And our developed system can intelligently reduce the malfunction of AQS from the dampness of air or dense fog with the backpropagation neural network and the input sensor module with four sensing elements such as reducing gas sensing element, oxidizing gas sensing element, temperature sensing element and humidity sensing element.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.6
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• pp.1125-1132
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• 2012

The researches on driver assistance systems that can prevent an accident have been actively performed due to social issues of traffic accidents with development of vehicle industry in recent. It is required for researchers to develope systems which assist driver's perception and judgment when considering that over 70% of traffic accidents occur by drivers' carelessness and 75% of the total accidents occur at the speed of less 29km per hour. In this paper, we implemented a front and rear vehicle monitoring system that monitors distance from a vehicle to obstacles in real-time at the low-speed or back-ward driving. The proposed system consists of ultrasonic sensors of high angle and wide angle of beam spread, ATmega128, and DSP processor.

• Proceedings of the KIEE Conference
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• 2006.11a
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• pp.87-89
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• 2006

현재 전력계통분야에서 신재생에너지원을 이용한 분산전원 (DG, Distributed Generation)이 확대 보급됨에 따라 이에 대한 기술의 높은 신뢰성 및 경제성이 높아지고 있는 시점이다. 이에 따라 분산전원의 효율 적운용을 위한 모니터링 장치의 필요성이 또한 증대되고 있다. 본 논문에서는 신재생에너지원 중 대표적인 태양 광발전시스템의 현재 상태 (전압 전류, 전력, 위상, 주파 수)를 계통의 모니터링을 위해 제작한 ATmega 128(AVR)이 내장된 Power Line Data Acquisition Board와 현재 널리 통용되는 GUI시스템인 $LabVIEW^{TM}$를 이용하여 컴퓨터를 통한 태양광발전시스템을 모니터링 하는 프로그램을 구현하고자 한다.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.143-144
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• 2008

By using Ez-RoboMaster which is developed in EASYTECH, we implement an intelligent robot system. The Ez-RoboMaster is developed based on AVR Atmega128, and the emdedded system contains 5 ports for several sensors and actuators. And we develop integrated development environment(IDE), Ez-CPU3.0 for easy application of Ez-RoboMaster. In this paper, we introduce the effectiveness of Ez-RoboMaster for educational platforms of intelligent robot systems at college and university.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.139-140
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• 2010

This paper presents an indoor prototype for wireless digital signal transmission using Visible Light Communications (VLC) in which high power Light Emitting Diode (LED) is used. Using low cost and off-the-shelf components, the transmitter module is constructed using an AVR Atmega128 microcontroller and commercial white beam LEDs. Modulating the light intensity of the LED enables digital signals to be transmitted across the optical link. The receiver module employs a high speed PIN photodetector for optical signal detection and a recovery circuit for optical-electro signal conversion. By sending digitalized data via VLC technology, many applications can be realized in the areas of consumer advertising, traffic safety information and disaster control.

• Journal of Chest Surgery
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• v.44 no.6
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• pp.399-405
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• 2011

Background: Left ventricular (LV) hypertrophy caused by aortic valve stenosis (AS) leads to cardiovascular morbidity and mortality. We sought to determine whether aortic valve replacement (AVR) decreases LV mass and improves LV function. Materials and Methods: Retrospective review for 358 consecutive patients, who underwent aortic valve replacement for degenerative AS between January 1995 and December 2008, was performed. There were 230 men and 128 women, and their age at operation was $63.2{\pm}10$ years (30~85 years). Results: There was no in-hospital mortality, and mean follow-up duration after discharge was 48.9 months (2~167 months). Immediate postoperative echocardiography revealed that LV mass index and mean gradient across the aortic valve decreased significantly (p<0.001), and LV mass continued to decrease during the follow-up period (p<0.001). LV ejection fraction (EF) temporarily decreased postoperatively (p<0.001), but LV function recovered immediately and continued to improve with a significant difference between preoperative and postoperative EF (p<0.001). There were 15 late deaths during the follow-up period, and overall survival at 5 and 10 years were 94% and 90%, respectively. On multivariable analysis, age at operation (p=0.008), concomitant coronary bypass surgery (p<0.003), lower preoperative LVEF (<40%) (p=0.0018), and higher EUROScore (>7) (p=0.045) were risk factors for late death. Conclusion: After AVR for degenerative AS, reduction of left ventricular mass and improvement of left ventricular function continue late after operation.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.5
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• pp.335-340
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• 2013

This paper has designed and realized educational ZigBee equipment befitting to the USN environment. In addition, this study has enabled users to exercise operation process for software technology education and to propose software design methods in the process in the USN environment through practice equipment for ZigBee education. As for the development environment of system, Atmega128 process of Atmel is used for CPU; AVR compiler for the debugging environment; C language for firmware development language; and C++ for application program. The system operation process is initiated by coordinator's sensing information reading order from the hyper terminal through a server through the Internet or directly connected; and then delivering it to a terminating device by using ZigBee technology. The terminating device delivers various sensing information to the coordinator which delivers it to a server through the Internet or to a HYPER terminal directly connected to the coordinator. As for the educational course, it is about practices on such ZigBee operation process and relevant programing skills. Regarding it, the communication between coordinator and terminating device is designed by utilizing physical layer of ZigBee protocol, MAC layer and network layer while the communication between server and coordinator is designed by proposing an independent protocol on TCP/IP socket and the protocol processing procedure during sensing data delivery is verified by interpretation.