• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.450-453
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• 2002

In emergency telemedicine system based on wireless communication system with limited transmission capacity, it is necessary to transmit the biological data (ECG, BP, Respiration, $SpO_2$) of the patient continuously and reliably in real time. For this service, it is necessary to data compression and error control. In this study, we designed an protocol for error control in application layer and implemented it on the biological data transmission program for an emergency telemedicine system based on wireless data communication system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.26-26
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• 2004

산업용으로 주로 쓰이던 로봇이 인간의 생활에 밀접하게 다가오면서 인간과 로봇의 활동공간의 공유가 늘어가고 있다. 이로 인하여 접하는 시간이 증대되어 인간과 친밀한 인터페이스 구현에 대한 연구가 활발히 진행되고 있으며, 이와 관련하여 지능형 로봇에 있어 음성시스템은 필수적이다. 최근 통신분야와 관련하여 음성인식과 음성합성의 기술이 급속히 발전하고 있으나, 음성인식에 있어 현재 헤드？을 이용하거나 마이크로폰에서 약 30cm정도 떨어진 거리에서 음성을 인식하는 것이 일반적이며, 그 이상의 거리에서나 잡음이 존재하는 실제 환경에서 인식률이 급격히 떨어져 이동롯봇과 같은 실용시스템과의 접목하는 기술이 부족한 상황이다.(중략)

• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.1
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• pp.41-46
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• 2008

With widespread use of the Internet and improvements in streaming media and compression technology, digital music, video, and image can be distributed instantaneously across the Internet to end-users. However, most conventional Digital Right Management are often not secure and fast enough to process the vast amount of data generated by the multimedia applications to meet the real-time constraints. In this paper, we propose the copyright protection using encryption of DCT coefficients and motion vector in MPEG-4 video codec of mobile device. This paper presents a new Digital Rights Management that modifies the Motion Vector of Macroblock for mobile device. Experimental results indicate that the proposed DRM can not only achieve very low cost of the encryption but also enable separable authentication to individual mobile devices such as Portable Multimedia Player and Personal Digital Assistants. The performance of the proposed methods have low complexity and low increase of bit rate in overhead.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1997.11a
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• pp.63-67
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• 1997

The ISO(International Standard Organization) has standardized MPEG-2 audio. The MPEG-2 audio compression algorithm is based upon subband analysis and exploits the human auditory characteristics to achieve a low bit rate with minimum perceptual loss of audio signal quality. This thesis presents an enhanced MPEG-2 audio encoder using multiple TMS320C30 general purpose DSP's. The developed system is made up of five slave boards and one master board. Each slave board performs susband analysis psychoacoustic parameter calculation for one channel, and the master board manages bit allocation, quantization, and bit-stream formatting for all channels. Parallel processing and pipelining techniques are used in hardware structure and fast algorithms are applied in each subroutine to implement a real-time process. The implemented system supports multichannel up to 5.1 and various bitrates.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.4
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• pp.148-152
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• 2007

This paper develops an integrated optic transmitter/receiver based on ring-type WDM PON. The optic transmitter/receiver can transmit real-time images from the CCTV of a remote street without compression and transmit TCP/IP data using an optic fiber. This system can also perform remote controls of the CCTV camera. The developed optic transmitter/receiver can provide the monitoring service of an advanced image quality of remote traffic using a broadband technology.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.1
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• pp.73-81
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• 2003

An autonomous stair robot recognizing the stair, and climbing up and down the stair by utilizing a robot vision, photo sensors, and appropriate climbing algorithm is introduced. Four arms associated with four wheels make the robot climb up and down more safely and faster than a simple track typed robot. The robot can adjust wheel base according to the stair width, hence it can adopt to a variable width stair with different algorithms in climbing up and down. The command and image data acquired from the robot are transferred to the main computer through RF wireless modules, and the data are delivered to a remote computer via a network communication through a proper data compression, thus, the real time image monitoring is implemented effectively.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.967-968
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• 2006

This paper proposes a novel system to send images in a narrow band network and to measure water level. In order to send images in narrow band network, we use JPEG compression technique based on the difference image. The difference image is obtained by subtracting the current image from the predefined reference image. The water level is measured to make use of the camera calibration and the edge information of the received image.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.411-412
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• 2006

In this paper, we proposed a fast algorithm for inter prediction included the most complexity in H.264/AVC. It decide search range according to direction of predicted motion vector, and then perform adaptive candidate spiral search. Simultaneously, it perform motion estimation of variable loop with threshold for variable block size. Conclusively, it is implemented in JM FME with high complexity applying to rate-distortion optimization. Experimental results show that significant complexity reduction is achieved while the degradation in video quality is negligible.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2070-2075
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• 2008

Identification of steady-state is the first step in developing a fault detection and diagnosis (FDD) system. In a complete FDD system, the steady-state detector will be included as a module in a self-learning algorithm which enables the working system's reference model to "tune" itself to its particular installation. In this study, a steady-state detector of a residential air conditioner based on moving windows was designed. Seven representing measurements were selected as key features for steady-state detection. The optimized moving window size and the feature thresholds was suggested through startup transient test and no-fault steady-state test. Performance of the steady-state detector was verified during indoor load change test. From the research, the general methodology to design a moving window steady-state detector was provided for vapor compression applications.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.499-501
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• 2003

본 논문은 우선순위 스케줄링을 사용하는 주기적 실시간 시스템을 위해 제안된 확률적 분석 방법의 개선 방안을 제안한다. 기제안된 확률적 분석 방법은 (1) 시스템 적체 분석, (2) 작업별 적체 분석, (3) 작업별 간섭 분석을 거쳐서 각 태스크의 응답 시간 분포를 얻어냄으로써 태스크들의 종료시한 위반확률 (deadline miss probability)을 계산한다. 본 논문은 기제안된 확률적 분석 방법에 대해 주어진 태스크 집합의 하이퍼주기(hyperperiod)를 압축하여 시스템 적체 분석을 개선시킬 수 있음을 보인다. 하이퍼주기 압축 기법은 시스템 적체 분석에 요구되는 계산 시간을 단축시키고, 계산된 각 태스크의 종료시한 위반확률이 항상 원래 확률값의 상한(upper bound)이 된다는 장점이 있다. 실험 결과. 하이퍼주기 압축 기법이 정확도의 손실을 최소화하면서 상당한 계산 시간 단축을 가져올 수 있음을 확인하였다.