• Title/Summary/Keyword: 반복 제곱법

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Analysis of 1-D Free boundary Problem Using Implicit Moving-Least-Squares Difference Method (Implicit 이동최소제곱 차분법을 이용한 1차원 자유경계문제의 해석)

  • Yoon, Young-Cheol
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2010.04a
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    • pp.48-51
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    • 2010
  • 본 논문에서는 자유경계문제 해석을 위해 정확도가 향상된 implicit 이동최소제곱 차분법을 제시한다. 계면경계에 대한 implicit 정의로 인해 비선형 시스템이 구성되고, 매 해석단계마다 절점해와 계면경계의 위치를 반복계산을 통해 찾는다. 계면경계 결정시 속도항을 한 단계 뒤로 지연시켜 explicit하게 근사적으로 계산하던 기존 방법에 비해 계면경계의 위치를 더 정확하게 계산할 수 있고, 결과적으로 해의 정확도가 향상되었다. 계면경계 위치값이 비교적 빠른 속도로 수렴하기 때문에 많은 반복계산이 필요치 않다. 수치예제를 통해 기존의 방법으로 계산한 결과와 비교하여 새롭게 개발한 implicit 방법의 향상된 정확도를 보였다.

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Implicit Moving Least Squares Difference Method for 1-D Moving Boundary Problem (1차원 자유경계문제의 해석을 위한 Implicit 이동최소제곱 차분법)

  • Yoon, Young-Cheol
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.25 no.5
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    • pp.439-446
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    • 2012
  • This paper presents an implicit moving least squares(MLS) difference method for improving the solution accuracy of 1-D free boundary problems, which implicitly updates the topology change of moving interface. The conventional MLS difference method explicitly updates the moving interface; it requires no iterative solution procedure but results in the loss of accuracy. However, the newly developed implicit scheme makes the total system nonlinear involving iterative solution procedure, but numerical verification show that it dramatically elevates the solution accuracy with moderate computation increase. Through numerical experiments for melting problems having moving singularity, it is verified that the proposed method can achieve the second order accuracy.

이변량 반복측정자료에서 가중일치상관계수의 추정

  • 강보경;김규성
    • Proceedings of the Korean Statistical Society Conference
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    • 2000.11a
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    • pp.261-266
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    • 2000
  • 이변량 반복측정자료에서 Chinchilli 등(1996)이 제안한 가중일치상관계수는 두 변수의 일치성을 나타내는 측도이다. 기존에 제안된 가중일치상관계수 추정법은 변동효과 및 측정오차의 분산성분을 각각 최소제곱법으로 비편향 추정하여 구하는 것이다. 본 연구에서는 반복측정자료의 주변 우도함수를 설정한 후, 우도함수에 기초한 분산성분을 구하여 가중일치상관계수를 추정하는 방법을 제안한다. 이때, 각 분산성분은 유사/의사 우도함수 및 사후 분포에서 반복시행을 통하여 구해진다.

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A Generalized Marginal Logit Model for Repeated Polytomous Response Data (반복측정의 다가 반응자료에 대한 일반화된 주변 로짓모형)

  • Choi, Jae-Sung
    • The Korean Journal of Applied Statistics
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    • v.21 no.4
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    • pp.621-630
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    • 2008
  • This paper discusses how to construct a generalized marginal logit model for analyzing repeated polytomous response data when some factors are applied to larger experimental units as treatments and time to a smaller experimental unit as a repeated measures factor. So, two different experimental sizes are considered. Weighted least squares(WLS) methods are used for estimating fixed effects in the suggested model.

Design of VLSI Architecture for Efficient Exponentiation on $GF(2^m)$ ($GF(2^m)$ 상에서의 효율적인 지수제곱 연산을 위한 VLSI Architecture 설계)

  • 한영모
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.41 no.6
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    • pp.27-35
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    • 2004
  • Finite or Galois fields have been used in numerous applications such as error correcting codes, digital signal processing and cryptography. These applications often require exponetiation on GF(2$^{m}$ ) which is a very computationally intensive operation. Most of the existing methods implemented the exponetiation by iterative methods using repeated multiplications, which leads to much computational load, or needed much hardware cost because of their structural complexity in implementing. In this paper, we present an effective VLSI architecture for exponentiation on GF(2$^{m}$ ). This circuit computes the exponentiation by multiplying product terms, each of which corresponds to an exponent bit. Until now use of this type algorithm has been confined to a primitive element but we generalize it to any elements in GF(2$^{m}$ ).

A Logit Model for Repeated Binary Response Data (반복측정의 이가반응 자료에 대한 로짓 모형)

  • Choi, Jae-Sung
    • The Korean Journal of Applied Statistics
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    • v.21 no.2
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    • pp.291-299
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    • 2008
  • This paper discusses model building for repeated binary response data with different time-dependent covariates each occasion. Since repeated measurements data are having correlated structure, weighed least squares(WLS) methodology is applied. Repeated measures designs are usually having different sizes of experimental units like split-plot designs. However repeated measures designs differ from split-plot designs in that the levels of one or more factors cannot be randomly assigned to one or more of the sizes of experimental units in the experiment. In this case, the levels of time cannot be assigned at random to the time intervals. Because of this nonrandom assignment, the errors corresponding to the respective experimental units may have a covariance matrix. So, the estimates of effects included in a suggested logit model are obtained by using covariance structures.

Modular Exponentiation by m-Numeral System (m-진법 모듈러 지수연산)

  • Lee, Sang-Un
    • The KIPS Transactions:PartC
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    • v.18C no.1
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    • pp.1-6
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    • 2011
  • The performance and practicality of cryptosystem for encryption, decryption, and primality test is primarily determined by the implementation efficiency of the modular exponentiation of $a^b$(mod n). To compute $a^b$(mod n), the standard binary squaring still seems to be the best choice. But, the d-ary, (d=2,3,4,5,6) method is more efficient in large b bits. This paper suggests m-numeral system modular exponentiation. This method can be apply to$b{\equiv}0$(mod m), $2{\leq}m{\leq}16$. And, also suggests the another method that is exit the algorithm in the case of the result is 1 or a.

Statistical Analysis for Fatigue Life Evaluation of Vehicle Muffler (자동차용 머플러의 피로수명평가를 위한 통계적 분석)

  • Choi, Ji-Hun;Lee, Yong-Jun;Yoon, Jin-Ho;Kang, Sung-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.3
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    • pp.365-372
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    • 2013
  • In this study, a statistical method for evaluating the fatigue life of a vehicle muffler was used to obtain reliable fatigue data using a limited number of specimens. Cyclic bending tests were conducted using specimens manufactured to be exactly the same as the mufflers installed in cars that are currently in use. To estimate the fatigue life by comparing the data obtained during the fatigue tests, the most suitable probability density function for the normal, lognormal, and Weibull distributions was selected. A goodness-of-fit test was performed on the probability distributions, and then a Weibull distribution using the least square method was selected. By using the selected Weibull distribution, the probability-moment-life curves (P-M-N curve) reflecting the fatigue characteristics were suggested as the data for the reliable design of a muffler.

Time delay estimation by iterative Wiener filter based recursive total least squares algorithm (반복형 위너 필터 방법에 기반한 재귀적 완전 최소 제곱 방법을 사용한 시간 지연 추정 알고리즘)

  • Lim, Jun-Seok
    • The Journal of the Acoustical Society of Korea
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    • v.40 no.5
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    • pp.452-459
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    • 2021
  • Estimating the mutual time delay between two acoustic sensors is used in various fields such as tracking and estimating the location of a target in room acoustics and sonar. In the time delay estimation methods, there are a non-parametric method, such as Generalized Cross Correlation (GCC), and a parametric method based on system identification. In this paper, we propose a time delay estimation method based on the parametric method. In particular, we propose a method that considers the noise in each receiving acoustic sensor. Simulation confirms that the proposed algorithm is superior to the existing generalized cross-correlation and adaptive eigenvalue analysis methods in white noise and reverberation environments.

Comparisons of Kruglyak and Lander's Nonparametric Linkage Test and Weighted Regression Incorporating Replications (KRUGLYAK과 LANDER의 유전연관성 비모수 방법과 반복 자료를 고려한 가중 회귀분석법의 비교)

  • Choi, Eun-Kyeong;Song, Hae-Hiang
    • The Korean Journal of Applied Statistics
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    • v.21 no.1
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    • pp.1-17
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    • 2008
  • The ordinary least squares regression method of Haseman and Elston(1972) is most widely used in genetic linkage studies for continuous traits of sib pairs. Kruglyak and Lander(1995) suggested a statistic which appears to be a nonparametric counterpart to the Haseman and Elston(1972)'s regression method, but in fact these two methods are quite different. In this paper the relationships between these two methods are described and will be compared by simulation studies. One of the characteristics of the sib-pair linkage study is that the explanatory variable has only three different values and thus dependent variable is heavily replicated in each value of the explanatory variable. We propose a weighted least squares regression method which is more appropriate to this situation and the efficiency of the weighted regression in genetic linkage study was explored with normal and non-normal simulated continuous traits data. Simulation studies demonstrated that the weighted regression is more powerful than other tests.