• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.4
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• pp.373-385
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• 1987

The scaled WDF should be optimized from the point of view of dynamic range. Transformer scaling method is attempted to maximize the dynamic range by equalizing the gains in the different nodes of the WDF. In this paper, the dual network and different frequencies are used to study the effects of different topology and of sampling frequency. Comparing with the unscaled WDF, the most significant observation is that the SNR is improved in the range of 7 to 35 dB in the WDF scaled by the trasnsformer scaling method. In addition, the SNR shows a continuous drop with the increase of sampling frequency, but scaling effects seem to decrease the rate at which the SNR drop.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.616-623
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• 2002

The fractal expanded antenna with the configuration of a triangular microstrip patch antenna is presented and analyzed. In the fundamental and higher mode of TFA(Triangular Fractal Antenna), resonant frequencies are controlled by changing the scaling factor. It is observed that increasing scaling factor makes the resonant frequency be spread, and decreasing scaling factor makes it be concentrated. The scaling factor is varied as the expansion and concentration of resonant frequencies. The resonant frequency in each fractal patch element is observed log -periodically. The TFA can be applied to the multiband system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.6
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• pp.21-27
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• 2019

The video compression standard required a processing technique for a high resoluion image and increased the coding size to increase the resolution of the image. Accurate motion estimation and increased coding size provide high accuracy and compression rate, but there is a problem of increased computational complexity. In this paper, we use DCT - based motion estimation in the frequency domain to reduce complexity. However, we found that the DCT and quantization process used in a general video encoder are applied to the frequency domain encoder, resulting in problems caused by the scaling process. Therfore, in this paper, we extract the scaling matrix that can be applied in the DCT step and resolve the, and improve the performance of motion estimation using increased coding size.

• Journal of Broadcast Engineering
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• v.14 no.5
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• pp.638-649
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• 2009

Image resizing (or scaling) is one of the most essential issues for the success of visual service because image data has to be adapted to the variety of display features. For 2D imaging, the image scaling is generally accomplished by 2D image re-sampling (i.e., up-/down-sampling). However, when it comes to stereoscopic 3D images, 2D re-sampling methods are inadequate because additional consideration on the third dimension of depth is not incorporated. Practically, stereoscopic 3D image scaling is process with left/right images, not stereoscopic 3D image itself, because the left/right Images are only tangible data. In this paper, we analyze stereoscopic 3D image scaling from two aspects: geometrical deformation and frequency-domain aliasing. A number of 3D displays are available in the market and they have various screen dimensions. As we have more varieties of the displays, efficient stereoscopic 3D image scaling is becoming more emphasized. We present the recommendations for the 3D scaling from the geometric analysis and propose a disparity-adaptive filter for anti-aliasing which could occur during the image scaling process.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.04a
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• pp.161-164
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• 2000

본 논문에서는 웨이블릿에 의한 원 영상의 주파수 성분들을 스케일링에 의한 해상도 변화를 이용하여, 여러개의 서브밴드들로 나누어질 수있다는 성질을 이용하여 각각의 서브밴드들을 이용하여 워터마크를 삽입·검출하는 기법을 제안하고 있다. 보통 디지털 워터마크는 크게 주파수 영역 워터마크와 공간 영역 워터마크의 두 가지 분야로 분류될 수 있다. 주파수 영역 워터마크는 영상 데이터를 주파수 공간으로 변환하고 그 주파수 영역들 중에서 인간의 시각에 덜 민감한 성분에 워터마크를 삽입하게 되고, 이는 인간 시각 시스템을 더 효과적으로 활용한 것으로 인간시각으로 감지할 수 없는 영역인 고주파수 성분에 워터마크를 삽입하게된다.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1998.10a
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• pp.1155-1158
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• 1998

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.388-390
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• 2006

컴퓨터 연구에 있어서 과거에는 주로 성능 향상을 위한 연구가 진행되었으나, 최근에는 모바일, 유비쿼터스 환경의 도래와 함께 성능에 비례한 전력 소모 문제가 최대의 연구 과제로 대두되고 있다. 전력 소모문제는 컴퓨터 시스템 중 가장 큰 부분을 차지하는 마이크로프로세서를 비롯하여 그래픽 프로세서 메모리, 하드디스크 드라이브를 포함하는 I/O 디바이스, 그리고 메인보드에서 소모되는 누설 전류에 이르기까지 다양한 부문에서 연구되어 지고 있다. 본 논문에서는 각 구성 요소를 모두 포함하는 컴퓨터 시스템에 있어서 전력 소모를 감소하기 위한 주파수 스케일링 방법을 설계 구현하고, 컴퓨터 시스템 레벨에서의 전력 감소 효과를 제시한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4B
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• pp.422-428
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• 2011

In this paper, we introduce system and channel modeling for an underwater ad hoc acoustic network with n regularly located nodes， and then analyze capacity scaling laws based on the model. A narrow-band model is assumed where the carrier frequency is allowed to scale as a function of n. In the network, we characterize in attenuation parameter that depends on the frequency scaling as well as the transmission distance. A cut-set upper bound on the throughput scaling is then derived in extended networks having unit node density. Our result indicates that the upper bound is inversely proportional to the attenuation parameter, thus resulting in a power-limited network. Furthermore, we describe an achievable scheme based on the simple nearest-neighbor multi-hop (MH) transmission. It is shown under extended networks that the MH scheme is order-optimal for all the operating regimes expressed as functions of the attenuation parameter.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.203-206
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• 2008

기존의 대표적인 디지털 통신방식으로 주파수 편이 변조(FSK: frequency shift keying), 위상 편이 변조(PSK: phase shift keying), 진폭 편이 변조(ASK: amplitude shift keying) 방식들이 있다. 본 논문에서는 2진 정합필터를 이용하여 웨이브릿 편이변조 신호를 복원하는 알고리즘을 제안한다. 웨이브릿 편이 변조 시스템은 스케일링 함수(scaling function)와 웨이브릿(wavelet)을 이용한다. 스케일링 함수를 1로, 웨이브릿 함수를 0으로 할당하여 2진 데이터를 변조한다. 기존의 웨이브릿 편이 변조 시스템에서는 복원을 위해 후처리가 필요하였다. 된 논문에서는 2진정합필터를 이용하여 복원하므로, 별도의 후처리 과정 없이 복원을 가능하게 하였다. 모의실험 결과 제안한 알고리즘이 타당함을 확인하였다.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.2
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• pp.98-103
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• 2008

There are the frequency shift keying(FSK), phase shift keying(PSK) and amplitude shift keying(ASK) in the conventional digital communications method. In this paper, We proposed a new robust wavelet shift keying system using scaling and wavelet function in the digital communication. Wavelet Transform consist of a low frequency and high frequency coefficient. When the input signal is one, if it finds the impulse response, the signal is separated from the scaling and wavelet function. The binary data is encoded by modulator which assigned the scaling function to 1(one), and wavelet to zero(0). It was demonstrated by experiment that the proposed algorithm can be a robust noise.