• 제목/요약/키워드: Variance based method

검색결과 950건 처리시간 0.031초

웨이브렛을 이용한 공간적 영역분할에 의한 얼굴 인식 (Wavelet-Based Face Recognition by Divided Area)

  • 이성록;이상효;조창호;조도현;이상철
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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    • pp.2307-2310
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    • 2003
  • In this paper, a method for face recognition based on the wavelet packet decomposition is proposed. In the proposed method, the input image is decomposed by the 2-level wavelet packet transformation and then the face areas are defined by the Integral Projection technique applied to each of the 1-level subband images, HL and LH. After the defined face areas are divided into three areas, called top, bottom, and border, the mean and the variance of the three areas of the approximation image are computed, and the variance of the single predetermined face area for the rest of 15 detail images, from which the feature vectors of statistical measure are extracted. In this paper we use the wavelet packet decomposition, a generalization of the classical wavelet decomposition, to obtain its richer signal analysis features such as discontinuity in higher derivatives, self-similarity, etc. And we have shown that even with very simple statistical features such as mean values and variance we can make an excellent basis for face classification, if an appropriate probability distance is used.

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분산분해와 뎁트랭크를 활용한 정보흐름에 기반으로 시스템 위험 측정에 관한 실증연구 (An Empirical Study on Measuring Systemic Risk Based on Information Flows using Variance Decomposition and DebtRank)

  • 박아영;김호용;오갑진
    • 한국경영과학회지
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    • 제40권4호
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    • pp.35-48
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    • 2015
  • We analyze the systemic risk based on the information flows using the variance decomposition, DebtRank methods, and the Industry Sector Indices during 2001. 01 to 2015. 08. Using the KOSPI stock market as our setting, we find that (i) the systemic risk calculated by information flows of variance decompositions method shows strong positive relations with the market volatility, (ii) the magnitude of systemic risk measured from the information flows network by DebtRank method increases after the subprime financial crisis.

Complex Segregation Analysis of Total Milk Yield in Churra Dairy Ewes

  • Ilahi, Houcine;Othmane, M. Houcine
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권3호
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    • pp.330-335
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    • 2011
  • The mode of inheritance of total milk yield and its genetic parameters were investigated in Churra dairy sheep through segregation analyses using a Monte Carlo Markov Chains (MCMC) method. Data which consisted of 7,126 lactations belonging to 5,154 ewes were collected between 1999 and 2002 from 15 Spanish Churra dairy flocks. A postulated major gene was assumed to be additive and priors used for variance components were uniform. Based on 50 000 Gibbs samples from ten replicates chains of 100,000 cycles, the estimated marginal posterior means${\pm}$posterior standard deviations of variance components of milk yield were $23.17{\pm}18.42$, $65.20{\pm}25.05$, $120.40{\pm}42.12$ and $420.83{\pm}40.26$ for major gene variance ($\sigma_G^2$), polygenic variance ($\sigma_u^2$), permanent environmental variance ($\sigma_{pe}^2$) and error variance ($\sigma_e^2$), respectively. The results of this study showed the postulated major locus was not significant, and the 95% highest posterior density regions ($HPDs_{95%}$) of most major gene parameters included 0, and particularly for the major gene variance. The estimated transmission probabilities for the 95% highest posterior density regions ($HPDs_{95%}$) were overlapped. These results indicated that segregation of a major gene was unlikely and that the mode of inheritance of total milk yield in Churra dairy sheep is purely polygenic. Based on 50,000 Gibbs samples from ten replicates chains of 100,000 cycles, the estimated polygenic heritability and repeatability were $h^2=0.20{\pm}0.05$ and r=$0.34{\pm}0.06$, respectively.

중첩오차를 갖는 중회귀모형에서 분산의 신뢰구간 (Confidence intervals on variance components in multiple regression model with one-fold nested error strucutre)

  • 박동준
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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    • pp.495-498
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    • 1996
  • Regression model with nested error structure interval estimations about variability on different stages are proposed. This article derives an approximate confidence interval on the variance in the first stage and an exact confidence interval on the variance in the second stage in two stage regression model. The approximate confidence interval is based on Ting et al. (1990) method. Computer simulation is provided to show that the approximate confidence interval maintains the stated confidence coefficient.

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퍼지 뉴럴 네트워크 기반 다중모델 기법 추적 시스템 (A Fuzzy-Neural Network-Based IMM Method Tracking System)

  • 손현승;주영훈;박진배
    • 한국지능시스템학회논문지
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    • 제16권4호
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    • pp.472-478
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    • 2006
  • 본 논문에서는 기동표적의 추적에 대한 새로운 퍼지 뉴럴 네트워크 기반의 다중모델 기법을 소개한다. 표적의 가속도를 효과적으로 다루기 위하여, 이 논문에서는 표적의 가속도를 시변 변수인 표적의 추가적인 잡음으로 두고 각각의 가속도 간격의 정도에 따라 얻어지는 모든 잡음에 대한 변수에 의해 각각의 하부 모델들을 특성화시켰다. 모르는 가속도에 따른 시변 변수를 적응적으로 어립잡기는 어렵기 때문에 정밀한 계산을 위하여 퍼지 뉴럴 네트워크가 이용되었다. 퍼지 뉴럴 네트워크의 동정을 위해서는 오차 역전파 학습법을 사용하였다. 그리고 제안된 알고리즘의 수행 가능성을 보여주기 위하여 몇 가지 예를 제시하였다.

판 구조물의 감도해석 및 신뢰성해석 (Sensitivity and Reliability Analysis of Elate)

  • 김지호;양영순
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1991년도 가을 학술발표회 논문집
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    • pp.57-62
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    • 1991
  • For the purpose of developing the method for efficiently calculating the design sensitivity and the reliability for the complicated structure such as ship structure, the probabilistic finite element method is introduced to formulate the deterministic design sensitivity analysis method and incorporated with the second moment reliability methods such as MVFOSM, AFOSM and SORM. Also, the probabilistic design sensitivity analysis needed in the reliability-based design is performed. The reliability analysis is carried out for the initial yielding failure, in which the derivative derived in the deterministic desin sensitivity is used. The present PFEM-based reliability method shows good agreement with Monte Carlo method in terms with the variance of response and the associated probability of failure even at the first or first few iteration steps. The probabilistic design sensitivity analysis evaluates explicitly the contribution of each random variable to probability of failure. Further, the reliability index variation can be easily predicted by the variation of the mean and the variance of the random variables.

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A Robust Optimization Using the Statistics Based on Kriging Metamodel

  • Lee Kwon-Hee;Kang Dong-Heon
    • Journal of Mechanical Science and Technology
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    • 제20권8호
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    • pp.1169-1182
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    • 2006
  • Robust design technology has been applied to versatile engineering problems to ensure consistency in product performance. Since 1980s, the concept of robust design has been introduced to numerical optimization field, which is called the robust optimization. The robustness in the robust optimization is determined by a measure of insensitiveness with respect to the variation of a response. However, there are significant difficulties associated with the calculation of variations represented as its mean and variance. To overcome the current limitation, this research presents an implementation of the approximate statistical moment method based on kriging metamodel. Two sampling methods are simultaneously utilized to obtain the sequential surrogate model of a response. The statistics such as mean and variance are obtained based on the reliable kriging model and the second-order statistical approximation method. Then, the simulated annealing algorithm of global optimization methods is adopted to find the global robust optimum. The mathematical problem and the two-bar design problem are investigated to show the validity of the proposed method.

재표집방법에 의한 공정관리지수의 신뢰구간 (Confidence Interval for Capability Process Indices by the Resampling Method)

  • 남경현
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제1권1호
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    • pp.55-63
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    • 2001
  • In this paper, we utilize the asymptotic variance of $C_{pk}$ to propose a two-sided confidence interval based on percentile-t bootstrap method. This confidence interval is compared with the ones based on the standard and percentile bootstrap methods. Simulation results show that percentile-t bootstrap method is preferred to other methods for constructing the confidence interval.l.

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현저성과 분산을 이용한 적외선과 가시영상의 2단계 스케일 융합방법 (Two Scale Fusion Method of Infrared and Visible Images Using Saliency and Variance)

  • 김영춘;안상호
    • 한국멀티미디어학회논문지
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    • 제19권12호
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    • pp.1951-1959
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    • 2016
  • In this paper, we propose a two-scale fusion method for infrared and visible images using saliency and variance. The images are separated into two scales respectively: a base layer of low frequency component and a detailed layer of high frequency component. Then, these are synthesized using weight. The saliencies and the variances of the images are used as the fusion weights for the two-scale images. The proposed method is tested on several image pairs, and its performance is evaluated quantitatively by using objective fusion metrics.

Variance function estimation with LS-SVM for replicated data

  • Shim, Joo-Yong;Park, Hye-Jung;Seok, Kyung-Ha
    • Journal of the Korean Data and Information Science Society
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    • 제20권5호
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    • pp.925-931
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    • 2009
  • In this paper we propose a variance function estimation method for replicated data based on averages of squared residuals obtained from estimated mean function by the least squares support vector machine. Newton-Raphson method is used to obtain associated parameter vector for the variance function estimation. Furthermore, the cross validation functions are introduced to select the hyper-parameters which affect the performance of the proposed estimation method. Experimental results are then presented which illustrate the performance of the proposed procedure.

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