• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.449-452
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• 2005

For home networking system with a function of air quality monitoring, a wireless sensor module with several air quality monitoring sensors was developed for indoor environment monitoring system in home networking. The module has various enlargements for various kinds of sensors such as humidity sensor, temperature sensor, CO2 sensor, flying dust sensor, and etc. The developed wireless module is very convenient to be installed on the wall of a room or office, and the sensors in the module can be easily replaced due to well designed module structure and RF connection method. To reduce the system cost, only one RF transmission block was used for sensors' signal transmission to 8051 microcontroller board in time sharing method. In this home networking system, various indoor environmental parameters could be monitored in real time from RF wireless sensor module. Indoor vision was transferred to client PC or PDA from surveillance camera installed indoor or desired site. Web server using Oracle DB was used for saving the visions by web-camera and various data from wireless sensor module.

• 전기의세계
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• 제24권4호
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• pp.63-70
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• 1975

The speed characteristics of the diesel engines driving alternators are very important because it is directly concerned to the quality of electric power especially when electric power is supplied by a single alternator. In this paper, the speed characteristics of th diesel engine, equipped with a centrifugal mechanical governor, driving an alternator is dealt when load changes stepwise. The all coefficients included in the block diagram of the speed control system are estimated by actual experiments and the effects of gain change of the governor in the speed characteristics are examined theoretically and experimentally. The obtained result seems to be satisfactory and very useful for the improvement of quality of electric power supplied by a single alternator driven by the diesel engine especially for electric power system of ships.

• 대한전자공학회논문지
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• 제25권1호
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• pp.81-87
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• 1988

This paper proposes a new EBTC(extended block truncation coding) algorithm extended from the BTC for image compression. The EBTC has a capability to eliminate the defects of BTC, such as the deterioration of resolution or blocky effect,and to make a real-time processing like BTC. It shows better performances than the DPCM and the transform coding. Especially, it is a suitable coding method for the high quality picture transmission. It may be adequate to the system of transmission rate of 30-50 Mbits/sec. The picture quality has been scarecely degraded with a vector quantization to the EBTC output at the bit rate of 1.25 bits/pel. The bit rate of the scalar quantized EBTC method is 2.6-3.7 bits/pel.

• IEIE Transactions on Smart Processing and Computing
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• 제5권4호
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• pp.243-249
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• 2016

This paper proposes a new watermarking algorithm to embed watermarks in thr process of sample adaptive offsets (SAO) for high efficiency video coding (HEVC) compressed videos. The proposed method embeds two-bit watermark into the SAO offsets for each coding tree unit (CTU). To minimize visual quality degradation caused by embedding watermark, watermark bits are embedded into SAO offset depending on the SAO types of block. Furthermore, the embedded watermark can be extracted by simply adding four offsets and checking their least significant bits (LSB) at the decoder side. The experimental results show that the proposed method achieves 0.3% BD-rate increase without much visual quality degradation. Two-bit watermark for each CTU is embedded for more bit watermarking. In addition, the proposed method requires negligible computational load for watermark insertion and extraction.

• 한국멀티미디어학회논문지
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• 제18권2호
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• pp.158-167
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• 2015

This study presents a new method to improve the speed of high quality volume rendering. We improve the speed of ambient occlusion which is one of the global illumination techniques used in traditional volume visualization. Calculating ambient occlusion takes much time because it determines an illumination value of a sample by integrating opacities of nearby samples. This study proposes an improved method for this by using local statistics such as averages and standard deviations. We calculate local statistics for each volume block, a set of nearby samples, in pre-processing time. In the rendering process, we efficiently determine the illumination value by assuming the density distribution as a normal distribution. As the results, we can generate high quality images that combine ambient occlusion illumination with local illumination in real time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.116-118
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• 2002

Of all known power quality problems, voltage sags provide the largest reason for concern. Sags occurs more frequently than outages and therefore tend to be more costly for industry as modern technical equipment becomes all the more sensitive to the quality and reliability of supply. Therefore we designed for a new model for Voltage Sag compensator, and we will implement Anti-Windup PI Controller with IP Block.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.19-22
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• 2000

In this paper, we propose a watermarking method for still images using Discrete Cosine Transform (DCT). Watermarking is a copyright protection technique for digital contents by hiding secret information into the contents. The proposed method embeds the watermark information into DCT coefficients. To obtain a watermarked image that is not only high quality but also has robustness for compression, we considered a method to change the degree of embedding by utilizing the activity of each DCT block. The simulation results show that the proposed scheme can obtain huh quality watermarked images and we can extract most of the embedded data even if they are compressed by JPEG scheme.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.43-45
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• 2000

For motion estimation, the block matching algorithm is widely used to improve the compression ratio of low bit-rate motion video. As a newly developed fast search algorithm, the nearest-neighbors search technique has a drawback of degrading video quality while providing fisher speed in search process. In this paper, a modified nearest-neighbors search algorithm is proposed in which a double rectangular shaped search-candidate area is used to improve video quality in encoding process with a small increasing of search time. To evaluate the proposed algorithm. other methods based on the nearest-neighbors search algorithm are investigated.

• Journal of Information Processing Systems
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• 제7권1호
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• pp.103-110
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• 2011

In this paper, an adaptive motion vector smoothing scheme based on weighted vector median filtering is proposed in order to eliminate the motion outliers more effectively for improving the quality of side information in frame-based distributed video coding. We use a simple motion vector outlier reliability measure for each block in a motion compensated interpolated frame and apply weighted vector median filtering only to the blocks with unreliable motion vectors. Simulation results show that the proposed adaptive motion vector smoothing algorithm improves the quality of the side information significantly while maintaining low complexity at the encoder in frame-based distributed video coding.

• ETRI Journal
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• 제33권2호
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• pp.145-154
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• 2011

We present a novel video codec for supporting entertainment-quality video. It has new coding tools such as an intra prediction with offset, integer sine transform, and enhanced block-based adaptive loop filter. These tools are used adaptively in the processing of intra prediction, transform, and loop filtering. In our experiments, the proposed codec achieved an average reduction of 13.35% in BD-rate relative to H.264/AVC for 720p sequences.