• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5C
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• pp.413-421
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• 2008

The paper derives asymptotic formulas for the MSE distortion and the signal-to-noise ratio of a mismatched fixed-rate minimum MSE Laplacian quantizer. These closed-form formulas are expressed in terms of the number N of quantization points, the mean displacement $\mu$, and the ratio $\rho$ of the standard deviation of the source to that for which the quantizer is optimally designed. Numerical results show that the principal formula is accurate in that, for rate R=$log_2N{\geq}6$, it predicts signal-to-noise ratios within 1% of the true values for a wide range of $\mu$, and $\rho$. The new findings herein include the fact that, for heavy variance mismatch of ${\rho}>3/2$, the signal-to-noise ratio increases at the rate of $9/\rho$ dB/bit, which is slower than the usual 6 dB/bit, and the fact that an optimal uniform quantizer, though optimally designed, is slightly more than critically mismatched to the source. It is also found that signal-to-noise ratio loss due to $\mu$ is moderate. The derived formulas can be useful in quantization of speech or music signals, which are modeled well as Laplacian sources and have changing short-term variances.

• Geophysics and Geophysical Exploration
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• v.25 no.3
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• pp.120-128
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• 2022

There are 17,000 reservoir dams in Korea, of which more than 85% were built over 50 years ago. Old embankment dams are weakened by internal erosion and suffusion phenomena due to preferential leakage paths and this ongoing weakening can cause their failure. Therefore, early warning associated with leakage in an embankment dam is crucial to prevent its failure. An electrical resistivity survey is a non-destructive, real-time and in-situ technique for detecting the development of leakage zones and general conditions of embankment dams. Because of its advantages, the electrical resistivity survey is widely used for reservoir safety inspections. However, the electrical resistivity survey is still not officially included in the precise safety inspection of reservoir dams because it cannot present a quantitative index of dam safety. In this study, we propose a method for calculating the leak index according to the water content evaluated from the electrical resistivity survey and/or induced polarization survey. Particularly, by proposing a quantitative leak index calculation method from monitoring surveys and independent surveys, we provide a theoretical basis for including electrical resistivity and induced polarization surveys as components of the precise safety inspection of reservoirs dams.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.11
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• pp.2170-2178
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• 1994

Our previously proposed method is further applied to find the queue length distribution of MMPP/D1 in an ATM multiplexer. We derive some useful relationship between the queue distribution seen by arriving cells and for a server befor each service. The relations were used to improve out approximation. For MMPP/D1 the calculated results show a good agreement with those obtained by a simulation of the system. Furthermore, our approximation provides fast numerical algorithms for general traffic models. These advantages demomstrate that our approximation method is useful for a fast and accurate traffic analysis in ATM networks.

• Journal of The Korean Association of Information Education
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• v.15 no.3
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• pp.517-524
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• 2011

This paper presents a fast blind deconvolution method that produces a deblurring result from a single image in only a few seconds. The high speed of our method is enabled by considering the Discrete Fourier Transform (DFT), and its relation to filtering and convolution, and fast computation of Moore-Penrose inverse matrix. How can we predict the behavior of an arbitrary filter, or even more to the point design a filter to achieve certain specifications. The idea is to study the frequency response of the filter. This concept leads to an useful convolution formula. A Matlab implementation of our method usually takes less than one minute to deblur an image of moderate size, while the deblurring quality is comparable.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.6
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• pp.459-464
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• 2001

This paper discusses a stochastic stabilization of Takagi-Sugeno(TS) fuzzy system with Markovian input delay. The finite Markovian process is adopted to model the input delary of the overall control system. It is assumed that the zero and hold devices are used for control input. The continuous-time TS fuzzy system with the Markovian input delay is discretized for easy handling delay, according, the discretized TS fuzzy system is represented by a discrete-time TS fuzzy system with jumping parameters. The stochastic stabilizibility of the jump TS fuzzy system is derived and formulated in terms of linear matrix inequalities (LNIS)

• Journal of the Korean Data and Information Science Society
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• v.20 no.6
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• pp.1155-1167
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• 2009

We made a new sample design for life and consciousness survey of Kyungpook people in 2007. We used the 10% sample survey data of 2005 population and housing census as a survey population. After stratification, we allocate proportionally samples within strata after examining various characteristics in previous survey, which includes economic activity state, an income level per year, and housing possession. And we calculated weight in a new sample design and derived estimators and a formula of standard error using the weights.

• The Korean Journal of Applied Statistics
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• v.22 no.1
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• pp.141-151
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• 2009

According to the type of microdata, the various methods have been in use for masking microdata. Multiplicative noise is the one of popular schemes for masking continuous variables. In this paper, we introduce the method of masking based on multiplicative noise and show some results of the application on the 2006 Householder Income and Expenditure Survey (HIES) data. To create the multiplicative noise factor, we used the triangular distribution. truncated triangular distribution, trapezoidal distribution, and double triangular distribution. Also, formulas for the domain estimation for the data masked by the multiplicative noise are developed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.1
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• pp.140-145
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• 2005

The existing analytical expression for the voltage between the power and ground plane consist of metal-dielectric-metal board is expressed in the two dimensional infinite series. To reduce the computation time, the two dimensional infinite series is converted to the one dimensional infinite series using the summation formula of Fourier series. We applied these equations to the analysis of voltage between the $9‘{\times}4'$ size power-ground plane. The derived one dimensional infinite series shows the more rapid convergency and the more accurate result than the two dimensional infinite series. This equation can be applied to the power-ground plane analysis which needs a lot of the repeating computation.

• The Transactions of the Korea Information Processing Society
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• v.7 no.9
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• pp.3019-3028
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• 2000

One of the most frequently used spline scheme in CAD and graphics package is Bezier curve. Although simple and easy to implement, it supports diverse kinds of curves and surfaces. In view of the design convenience, the main advantage of the Bezier curves is that they observe user-specified slope conditions at both endpoints while maintaining smoothness. This paper expands the advantage by deriving equations for generalized Bezier curves, and applying the equation to observe additional slope condition at midpoint. This is possible by decomposing and analyzing the user-specified midpoint slope, and reflecting the result back into the Bezier basis matrix in parametric form. Consequently, users can control the curve shapes not only by the endpoint slope handles but also at the midpoint slope handle, which helps them to be able to apply more accurate control over the conventional Bezier curve shapes.

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.1
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• pp.87-102
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• 1990

개방식과수로는 낮은 압력으로 다량의 용수를 수송할 수 있는 장점을 갖고 있으나 유량변동에 의한 서어징현상이 현저한 것이 단점이다. 관로내의 흐름을 안정시키기 위해서는 이 서어징의 특성이 규명되어 대규모의 서어징에 대한 대책이 강구되어야 할 것이다. 개방식관수로계의 서어징을 강성수주이론으로 계산하기 위하여 운동방정식 연속방정식가 스탠드 수조의 중간벽에 설치된 언의 월유공식등을 조합한 기초방정식이 유도되었다. 본 연구의 수치해석 모델은 가장 일반적인 4차의 Runge-Kutter 방법을 사용하였으며, 이 모델의 정당성과 프로그램의 유통성을 검증하기 위하여 수리모형실험치와 수치해석치가 비교되었다. 그 결과 관로에 공기의 혼입이 없는 경우에는 실험치와 해석치가 실용상의 지장이 없는 정도로 잘 일치되었지만, 공기의 혼입이 발생되는 경우에는 실험치가 해석치에 비해 약간 크게 나타나서 이 경우에도 서러징의 해석이 가능한 새로운 모델의 개발이 필요한 것으로 생각된다. 또한 본 강성수주 모델을 이용하여 현재 서어징 문제로 곤란을 받고 있는 일본 자하연 비파호 부근의 용수간선을 대상으로 그 서어징의 특성과 개선방법을 경계한 결과 개설 개방식관수로계의 스탠드 중 매3개소 스탠드마다 1개소 스탠드의 하류측 수조 수면적 확장하는 것이 타당성이 있는 것으로 해석되었다.