• 한국전기화학회:학술대회논문집
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• 2002.04a
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• pp.39-39
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• 2002

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.2
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• pp.69-79
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• 1994

The conventional machine vision system which has uniform rectangular grid requires tremendous amount of computation for processing and analysing an image especially in 2-D image transfermations such as scaling, rotation and 3-D reconvery problem typical in robot application environment. In this study, the imaging system with nonuiformly distributed image sensors simulating human visual system, referred to as Ploar Exponential Grid(PEG), is compared with the existing conventional uniform rectangular grid system in terms of image resolution and computational complexity. By mimicking the geometric structure of the PEG sensor cell, we obtained PEG-like images using computer simulation. With the images obtained from the simulation, image resolution of the two systems are compared and some basic image processing tasks such as image scaling and rotation are implemented based on the PEG sensor system to examine its performance. Furthermore Fourier transform of PEG image is described and implemented in image analysis point of view. Also, the range and heading-angle measurement errors usually encountered in 3-D coordinates recovery with stereo camera system are claculated based on the PEG sensor system and compared with those obtained from the uniform rectangular grid system. In fact, the PEC imaging system not only reduces the computational requirements but also has scale and rotational invariance property in Fourier spectrum. Hence the PEG system has more suitable image coordinate system for image scaling, rotation, and image recognition problem. The range and heading-angle measurement errors with PEG system are less than those of uniform rectangular rectangular grid system in practical measurement range.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.1069-1074
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• 2008

This paper presents an efficient architecture for $2^n$-point DCT algorithm. The proposed approach makes use of the fact that, in most DCT applications, the scaling operation in the DCT unit can be eliminated and combined with the scaling operation in the quantizer unit. This important property is efficiently exploited with the CORDIC(COordinate Rotation DIgital Computer) algorithm to produce a regular architecture suitable for VLSI implementation. Although there have been several attempts to exploit CORDIC algorithm in developing DCT architectures, the proposed approach provides the most efficient way for scaled DCT applications by completely eliminating the scale factor compensation.

• Journal of applied mathematics & informatics
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• v.27 no.3_4
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• pp.463-473
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• 2009

A family of quasi-interpolatory wavelet system was introduced in [10], extending and unifing the biorthogonal Coiffman wavelet system. The corresponding refinable functions and wavelets have vanishing moment of a certain order (say, L), which is a key property for data representation and approximation. One of main advantages of this wavelet systems is that we can get optimal smoothness in the sense of smoothing factors in the scaling filters. In this paper, we first discuss the biorthogonality condition of the quisi-interpolatory wavelet system. Then, we study the properties of the scaling and wavelet filters, related to the polynomial reproduction and the vanishing moment respectively, which in fact determines the approximation orders of biorthogonal projections. In addition, we discuss the approximation orders of the wavelet projections.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.164-168
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• 2008

일반적으로 확률강우량은 관측지점에서 관측된 연최대 강우량자료를 바탕으로 빈도해석을 적용하여 산정한다. 그러나 국내에서는 매시각별로 관측된 자료가 대부분이기 때문에 단기간 혹은 장기간의 지속기간에 대한 확률강우량을 산정하는 것은 쉽지 않다. 따라서 본 연구에서는 매시각단위의 지속기간 강우자료를 바탕으로 다양한 지속기간에 대한 확률 강우량을 산정할 수 있는 스케일 성질을 적용하여 확률강우량을 산정하여 정확성을 판단하였다. 강우자료는 비교적 신뢰성이 높고 자료기간이 긴 기상청 지점 22개 자료를 사용하였으며, 2003년까지의 관측된 자료를 이용하여 확률강우량을 산정한 후 지점빈도해석 프로그램인 FARD2006과 비교하여 지점빈도해석의 결과 값을 참값으로 절대상대오차를 산정하여 비교하였다. 산정한 방법은 기준이 되는 확률강우량을 산정한 후 그보다 긴 지속기간에 대한 확률강우량을 산정하는 방법인 상향스케일링 (Up-scaling)과 그 보다 짧은 지속기간에 대한 확률강우량을 산정하는 방법인 하향스케일링(Down-scaling)의 두 가지 방법으로 확률강우량을 산정하였다. 두 방법 모두 1시간$\sim$24시간의 지속기간에 대한 확률강우량을 2년$\sim$500년의 재현기간에 대하여 확률강우량을 산정하였으며, 빈도해석으로 산정한 FARD2006의 결과값과 비교하여 절대상대오차를 산정하였다. 그 결과, 시간단위자료를 사용할 경우 대부분 절대상대오차가 10% 미만인 결과를 얻을 수 있었으며, 14개의 재현기간 중에서 8개 이상의 재현기간에 대해 적용이 가능한 것으로 나타났다. 지속기간 1시간 강우자료를 기준 지속기간으로 1시간 미만의 지속기간에 대한 확률강우량을 추정한 결과 10분을 제외하고는 대부분 절대상대오차가 10% 내외의 정확도를 가지는 것으로 나타났다. 따라서 스케일 성질을 이용하여 미계측 강우지속기간의 확률강우량을 추정할 수 있을 것으로 판단된다.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.107-110
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• 2001

In this paper, we propose a multiplication-free DFT kernel computation technique, whose input sequences are approximated into a ring of Algebraic Integers. This paper also gives computational examples for DFT and IDFT. And we proposes an architecture of the DFT using barrel shifts and adds. When the radix is greater than 4, the proposed method has a high Precision property without scaling errors due to twiddle factor multiplication. A possibility of higher radix system assumes that higher performance can be achievable for reducing the DFT stages in FFT.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.29-41
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• 2017

Design rainfalls are one of the most important hydrologic data for river management, hydraulic structure design and risk analysis. The design rainfalls are first estimated by a point frequency analysis and the IDF (intensity-duration-frequency) curve is then constructed by a nonlinear regression to either interpolate or extrapolate the design rainfalls for other durations which are not used in the frequency analysis. It has been widely recognised that the more reliable approaches are required to better account for uncertainties associated with the model parameters under circumstances where limited hydrologic data are available for the watershed of interest. For these reasons, this study developed a hierarchical Bayesian based GLM (generalized linear model) for a regional frequency analysis in conjunction with a scaling function of the parameters in probability distribution. The proposed model provided a reliable estimation of a set of parameters for each individual station, as well as offered a regional estimate of the parameters, which allow us to have a regional IDF curve. Overall, we expected the proposed model can be used for different aspects of water resources planning at various stages and in addition for the ungaged basin.

• Science of Emotion and Sensibility
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• v.19 no.3
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• pp.3-14
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• 2016

This study is aimed to measure the physical colorimetric property according to three conditions, natural dyestuffs (Gardenia, Sappan wood, Lac, Gardenia blue, Mugwort, and Indigo), fabric types (cotton, silk), and presence of mordant (without, with), and then to evaluate the psychological sensibility. Also, to perform analysis of variance (ANOVA) to find out the differences of physical properties according to the three natural dyeing conditions, and to analyze the relationship between physical property and psychological property by Pearson's correlation analysis and then suggest the prediction model by regression analysis using SPSS program (ver. 21.0). Finally, to propose a certain sensibility image map of naturally dyed fabrics, MDS (Multidimensional Scaling) was used, and as a result, Gardenia dyed fabrics having the color sensibilities such as 'hard' and 'heavy' were suggested to evoke masculine image, and to evoke feminine image, Sappan wood and Lac having 'bright', 'transparent', 'soft' and 'light' sensibilities were suggested. Natural image might be induced by using 'subdued' Mugwort dyed fabrics, and active image might be induced by using 'showy' Indigo dyed fabric.

• Geotechnical Engineering
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• v.11 no.3
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• pp.55-68
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• 1995

This paper is the analysis of the relationship between RQD and decay constant, blasting vi bration constant of cube root scaling and square root scaling, through experimental blast ins test in subway construction for excavation of shaft hole by bottom blasting. The magnitude of particle velocity is largely effected by the distance from blasting source, the maximum charge per delay and the properties of ground. In order to verify the effects of ground properties on blast-induced vibration, the relation-ship between magnitude of blasting vibration and Rock Quality Disignation which stands for joint property was studied. The results of test are verified that blasting vibration constant "K" and the absolute value("n") of decay constant relatively increse as RQD increased. According to the result, it can be predict the particle velocity by the blast -induced vibration in bottom blasting pattern.om blasting pattern.

• Journal of Korea Multimedia Society
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• v.4 no.3
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• pp.215-221
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• 2001

In this paper, we propose a algorithm that apply different weight-sampling values according to the directions of the contour to reduce errors that can arise in extracting the feature of an contoured object. Especially, it 8is designed to have invariant property under the circumstances like the rotation, transition and scaling. The output matrix of feature set is made through the size function of the proposed algorithm, and the euclidean distance between the output matrix and that of the original image is calculated. Experimental result shows that the proposed algorithm reduces the euclidean distance between the original image and the changed image-by 57% in rotation and by 91% in scaling.