• Journal of the Institute of Convergence Signal Processing
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• v.3 no.3
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• pp.14-20
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• 2002

In this paper, we proposed the compression technique of the video data using SPIHT(set partitioning in hierarchical trees) based on wavelet and the multi-stream delivery method for best-effort service as fully utilizing the clients bandwidth over the current Internet. The experiment shows that the proposed method provides about 1.5dB better picture quality without block effects than DCT(discrete consine transform) based coding schemes at the same bit rates because of using the wavelet video coder. In addition, this technique implements the multi-stream transmission based on TCP(transmission control protocol). Thus, it is provided with the best-efforts service which is robust to the network jitter problem, and maximally utilizes the bandwidth of the client's.

• The Transactions of the Korea Information Processing Society
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• v.5 no.4
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• pp.1048-1056
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• 1998

In this paper, a fractal image coding based on discrete wavelet transform is proposed to improve PSNR at low bit rates and reduce computational complexity of encoding process. The proposed method takes the absolute value of discrete wavelet transform coefficients, and then constructs significant coefficients trees, which indicate the positions and signs of the significant coefficients. This method improves PSNR and reduces computational complexity of mapping contracted domain pool onto range block, by matching only the significant coefficients of range block to coefficients of contracted domain block. Also, this paper proposes a classification scheme which minimizes the number of contracted domain blocks compared with range block. This scheme significantly reduces the number of range and contracted domain block comparison.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.5
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• pp.44-51
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• 2015

The deployment of high capacity backhaul is required due to explosive growth in mobile data services. For rapid backhaul deployment, point to point microwave is a much easier and cheaper technology. The space diversity scheme is used in point to point microwave links. The purpose of space diversity is to overcome fading by combining signals from two separate receiver antennas. For signal combining algorithm, maximum power and minimum distortion methods were used and these algorithms were reported not to be good enough for robustness in selective fading. In this paper, a more practically efficient signal combining scheme from the main and diversity branch is proposed and evaluated in selective fading channel. The proposed algorithm has shown significant performance improvement in terms of signal spectrum.

• Journal of Korea Multimedia Society
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• v.7 no.9
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• pp.1246-1254
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• 2004

This paper presents a image coding method that is well adaptive to close-range video transmission because of its low titrate and simple coding procedure. At first, it reduces temporal redundancies by performing image DPCM between previous frame and current frame, and makes wavelet transformed image of this difference image. Then, the coefficients are quantized selectively by using the coefficient values of base level and mid-frequency level because inter-level redundancies are widely exists in multi-resolution images. Finally quantized coefficients are made iron the function that implies the target bitrate, the average coefficient energy, and the value of the level. The proposed method shows the effective Performance in the experiments using the continuous motion images and transition images.

• Journal of the Korea Computer Industry Society
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• v.4 no.4
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• pp.589-598
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• 2003

In the conventional fractal image compression in the DWT(discrete wavelet transform), the domain and range blocks were classified as B${\times}$B block size first before all domain block for each range block was searched. The conventional method has a disadvantages that the encoding time takes too long, since the domain block for entire image was searched. As an enhancement to such inefficiencies and image quality, this paper proposes wavelet-based fractal image compression with multiscale factors. Thus, this proposed method uses multiscale factor along each level and band to enhance an overall image quality. In encoding process of this method, the range blocks are not searched for all the domain blocks; however, using the self affine system the range blocks are selected from the blocks in the upper level. The image qualify of the conventional method is 32.30[dB], and the proposed method is 35.97[dB]. The image quality is increased by 3.67[dB].

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.1-6
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• 2012

We suggested a microwave sensor structure and fabricated experimentally to detect particular particles in the air which are difficult to detect using conventional UWB sensors because their reaction frequencies to electromagnetic waves are too high. In the experiment to detect water particles in the air with up-conversion frequency of 10GHz, we verified detect signal amplitude variation of 75% depending on presence or absence of water particles. The suggested structure can be useful to detect particular materials at the high frequencies more than a few 10th GHz, because the same method can be applied to detect other materials.

• Journal of Digital Contents Society
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• v.10 no.4
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• pp.605-614
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• 2009

The software-defined radio (SDR) is a radio communication technology that can reconfigure necessary application software on a common hardware platform to deal with several kind of radio communication environment. It is necessary for a system that can control and analyze functionalities of a system in order to verify the SCA-based reconfigurable middleware platform, SCARLET that implements the SDR technology. In this paper, we propose and implement the architecture of the waveform manager that is connected with SCARLET and performs management and control functionalities. We verify the performance of the waveform manager by testing each functionality of the overall system that uses the SCARLET middleware platform.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.8
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• pp.731-735
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• 2001

In this paper, we propose the new audio watermarking method and can be used on line processing. Instead of the wavelet transform, we use the integer wavelet transform for the reduction of the computational load. The watermark associated with the chi-square distribution is inserted into the signal on the integer wavelet domain. When extracting the watermark, the spread spectrum methods are used with the coefficients associated with the covariance sequence. We show that the chi-square distribution is a good tool for the spread spectrum method on the wavelet domain. This watermarking technique may be sued for the control of the electrical product which can be controlled with the hidden signals and can be moved according to the audible signals simultaneously.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.3
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• pp.275-282
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• 1998

In this paper, we designed and fabricated 5-stage microwave solid state power amplifier using balanced amplifier scheme for X-band electronic radar reflector. The used substrate is FR4 and the used active devices are FHX35LC, FLK012WF and FLK022WG. The circuit design and optimization had been carried out through the microwave CAD program CNL2 The measured values show 46dB in gain, input return loss -14.2dB, output return loss -16.6dB and IM3 is 32dBc at designed bandwidth. The measured results are almost agreed with the simulated values.

• Journal of the Korea Computer Graphics Society
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• v.29 no.3
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• pp.59-67
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• 2023

This paper proposes a 3D animated body profile using 3D body scanning and motion capture devices. Users can create their own personalized body profiles with animation by performing 3D scans for a predetermined set of poses. To achieve this, a template animation was obtained through motion capture for a series of poses, and the acquired 3D scan data from users was mapped to the key poses of the animation using Pose-space deformer. The resulting 3D animated body profiles provide users with greater satisfaction compared to traditional static 2D images or 3D scan data.