• 제목/요약/키워드: non-linear methods

검색결과 1,005건 처리시간 0.027초

Single-step genomic evaluation for growth traits in a Mexican Braunvieh cattle population

  • Jonathan Emanuel Valerio-Hernandez;Agustin Ruiz-Flores;Mohammad Ali Nilforooshan;Paulino Perez-Rodriguez
    • Animal Bioscience
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    • 제36권7호
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    • pp.1003-1009
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    • 2023
  • Objective: The objective was to compare (pedigree-based) best linear unbiased prediction (BLUP), genomic BLUP (GBLUP), and single-step GBLUP (ssGBLUP) methods for genomic evaluation of growth traits in a Mexican Braunvieh cattle population. Methods: Birth (BW), weaning (WW), and yearling weight (YW) data of a Mexican Braunvieh cattle population were analyzed with BLUP, GBLUP, and ssGBLUP methods. These methods are differentiated by the additive genetic relationship matrix included in the model and the animals under evaluation. The predictive ability of the model was evaluated using random partitions of the data in training and testing sets, consistently predicting about 20% of genotyped animals on all occasions. For each partition, the Pearson correlation coefficient between adjusted phenotypes for fixed effects and non-genetic random effects and the estimated breeding values (EBV) were computed. Results: The random contemporary group (CG) effect explained about 50%, 45%, and 35% of the phenotypic variance in BW, WW, and YW, respectively. For the three methods, the CG effect explained the highest proportion of the phenotypic variances (except for YW-GBLUP). The heritability estimate obtained with GBLUP was the lowest for BW, while the highest heritability was obtained with BLUP. For WW, the highest heritability estimate was obtained with BLUP, the estimates obtained with GBLUP and ssGBLUP were similar. For YW, the heritability estimates obtained with GBLUP and BLUP were similar, and the lowest heritability was obtained with ssGBLUP. Pearson correlation coefficients between adjusted phenotypes for non-genetic effects and EBVs were the highest for BLUP, followed by ssBLUP and GBLUP. Conclusion: The successful implementation of genetic evaluations that include genotyped and non-genotyped animals in our study indicate a promising method for use in genetic improvement programs of Braunvieh cattle. Our findings showed that simultaneous evaluation of genotyped and non-genotyped animals improved prediction accuracy for growth traits even with a limited number of genotyped animals.

Permutation Predictor Tests in Linear Regression

  • Ryu, Hye Min;Woo, Min Ah;Lee, Kyungjin;Yoo, Jae Keun
    • Communications for Statistical Applications and Methods
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    • 제20권2호
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    • pp.147-155
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    • 2013
  • To determine whether each coefficient is equal to zero or not, usual $t$-tests are a popular choice (among others) in linear regression to practitioners because all statistical packages provide the statistics and their corresponding $p$-values. Under smaller samples (especially with non-normal errors) the tests often fail to correctly detect statistical significance. We propose a permutation approach by adopting a sufficient dimension reduction methodology to overcome this deficit. Numerical studies confirm that the proposed method has potential advantages over the t-tests. In addition, data analysis is also presented.

Analysis of slender structural elements under unilateral contact constraints

  • Silveira, Ricardo Azoubel Da Mota;Goncalves, Paulo Batista
    • Structural Engineering and Mechanics
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    • 제12권1호
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    • pp.35-50
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    • 2001
  • A numerical methodology is presented in this paper for the geometrically non-linear analysis of slender uni-dimensional structural elements under unilateral contact constraints. The finite element method together with an updated Lagrangian formulation is used to study the structural system. The unilateral constraints are imposed by tensionless supports or foundations. At each load step, in order to obtain the contact regions, the equilibrium equations are linearized and the contact problem is treated directly as a minimisation problem with inequality constraints, resulting in a linear complementarity problem (LCP). After the resulting LCP is solved by Lemke's pivoting algorithm, the contact regions are identified and the Newton-Raphson method is used together with path following methods to obtain the new contact forces and equilibrium configurations. The proposed methodology is illustrated by two examples and the results are compared with numerical and experimental results found in literature.

NUMERICAL SOLUTION OF THE NONLINEAR KORTEWEG-DE VRIES EQUATION BY USING CHEBYSHEV WAVELET COLLOCATION METHOD

  • BAKIR, Yasemin
    • 호남수학학술지
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    • 제43권3호
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    • pp.373-383
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    • 2021
  • In this study, a numerical method deals with the Chebyshev wavelet collocation and Adomian decomposition methods are proposed for solving Korteweg-de Vries equation. Integration of the Chebyshev wavelets operational matrices is derived. This problem is reduced to a system of non-linear algebraic equations by using their operational matrix. Thus, it becomes easier to solve KdV problem. The error estimation for the Chebyshev wavelet collocation method and ADM is investigated. The proposed method's validity and accuracy are demonstrated by numerical results. When the exact and approximate solutions are compared, for non-linear or linear partial differential equations, the Chebyshev wavelet collocation method is shown to be acceptable, efficient and accurate.

An Efficient Fingerprint Matching by Multiple Reference Points

  • Khongkraphan, Kittiya
    • Journal of Information Processing Systems
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    • 제15권1호
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    • pp.22-33
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    • 2019
  • This paper introduces an efficient fingerprint matching method based on multiple reference minutiae points. First, we attempt to effectively align two fingerprints by employing multiple reference minutiae points. However, the corresponding minutiae points between two fingerprints are ambiguous since a minutia of one fingerprint can be a match to any minutia of the other fingerprint. Therefore, we introduce a novel method based on linear classification concept to establish minutiae correspondences between two fingerprints. Each minutiae correspondence represents a possible alignment. For each possible alignment, a matching score is computed using minutiae and ridge orientation features and the maximum score is then selected to represent the similarity of the two fingerprints. The proposed method is evaluated using fingerprint databases, FVC2002 and FVC2004. In addition, we compare our approach with two existing methods and find that our approach outperforms them in term of matching accuracy, especially in the case of non-linear distorted fingerprints. Furthermore, the experiments show that our method provides additional advantages in low quality fingerprint images such as inaccurate position, missing minutiae, and spurious extracted minutiae.

NARDL 접근법을 사용한 에너지 안보와 경제성장에 대한 관계 분석 (An Analysis of the Relationship between Energy Security and Economic Growth Using the NARDL Approach)

  • 장국진;김진식;정명석;이주연
    • 시스템엔지니어링학술지
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    • 제18권2호
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    • pp.149-159
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    • 2022
  • This study investigated the relationship between economic growth and energy security risk levels in Korea using linear and non-linear ARDL methods. While there are many studies on the relationship between energy consumption and economic growth, few studies focus on the relationship between energy security and economic growth considering 4A dimensions of energy security such as energy availability, accessibility, acceptability, and affordability. Energy risk index from Global Energy Institue and GDP data from world bank are used for ARDL and NARDL analysis. Our result of ARDL shows that there is no long-term relationship between energy security risk levels and economic growth. On the other hand, NARDL result shows that there is an asymmetric relationship between economic growth and energy security risk levels in the long run. The results show the importance of expending further research on ensuring energy security to policymakers.

초연약 준설 매립지반의 비선형 유한변형 압밀해석기법 -Part I: 해석 물성치 평가 (Analysis Method for Non-Linear Finite Strain Consolidation for Soft Dredged Soil Deposit -Part I: Parameter Estimation for Analysis)

  • 곽태훈;이철호;임지희;안용훈;최항석
    • 한국지반공학회논문집
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    • 제27권9호
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    • pp.13-24
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    • 2011
  • Terzaghi의 1차원 압밀이론은 준설 매립지반과 같이 고함수비, 고압축성을 갖는 점토지반의 압밀해석에는 적합하지 않다. 준설 매립지반의 자중압밀과 재하하중에 의한 추가압밀을 적절히 고려하기 위해서는 비선형, 유한변형 압밀이론을 도입해야 한다. 준설 매립지반의 비선형 유한변형 압밀해석을 수행하기 위해서는 침강과정이 종료되고 자중압밀이 시작되는 시점의 간극비인 초기간극비($e_{00}$)와 비선형성을 갖는 준설토의 간극비-유효응력 관계와 간극비-투수계수의 관계 규명이 매우 중요하다. 본 연구에서는 실내시험을 통해 비선형 유한변형 압밀해석에 필요한 인자를 산정하는 방법을 제안하였다. 또한, 본 연구에서 제안한 방법을 적용하여 인천지역 준설토와 카올리나이트의 압밀 물성치를 평가하였고, 이를 동반논문에서 다룰 비선형 유한변형 압밀해석에 적용하였다.

Analysis of cable structures through energy minimization

  • Toklu, Yusuf Cengiz;Bekdas, Gebrail;Temur, Rasim
    • Structural Engineering and Mechanics
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    • 제62권6호
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    • pp.749-758
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    • 2017
  • In structural mechanics, traditional analyses methods usually employ matrix operations for obtaining displacement and internal forces of the structure under the external effects, such as distributed loads, earthquake or wind excitations, and temperature changing inter alia. These matrices are derived from the well-known principle of mechanics called minimum potential energy. According to this principle, a system can be in the equilibrium state only in case when the total potential energy of system is minimum. A close examination of the expression of the well-known equilibrium condition for linear problems, $P=K{\Delta}$, where P is the load vector, K is the stiffness matrix and ${\Delta}$ is the displacement vector, it is seen that, basically this principle searches the displacement set (or deformed shape) for a system that minimizes the total potential energy of it. Instead of using mathematical operations used in the conventional methods, with a different formulation, meta-heuristic algorithms can also be used for solving this minimization problem by defining total potential energy as objective function and displacements as design variables. Based on this idea the technique called Total Potential Optimization using Meta-heuristic Algorithms (TPO/MA) is proposed. The method has been successfully applied for linear and non-linear analyses of trusses and truss-like structures, and the results have shown that the approach is much more successful than conventional methods, especially for analyses of non-linear systems. In this study, the application of TPO/MA, with Harmony Search as the selected meta-heuristic algorithm, to cables net system is presented. The results have shown that the method is robust, powerful and accurate.

편심환내의 비선형 회전 유동 (Nonlinear Rotating Flows in Eccentric Cylinders)

  • 심우건
    • 대한기계학회논문집A
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    • 제24권1호
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    • pp.16-28
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    • 2000
  • The steady rotating flows in eccentric annulus has been studied by a numerical method based on the spectral collocation method. The inner cylinder has a constant angular velocity while the outer on e is stationary. Flow between eccentric cylinders is of considerable technical importance as it occurs in journal bearings. In the present work, the governing equations for laminar flow are expressed as Navier-Stokes equations, including the non-linear convection terms. The solutions were utilized i, estimate the effects of the nonlinear terms on the load acting on the rotating cylinder. Based on the half and the full Sommerfeld methods, the load on the rotating cylinder is evaluated with eccentricity, by integrating the pressure and skin friction around the cylinder. The attitude angle and Sommerfeld reciprocal are calculated from the load. Also, the torque on the rotating inner cylinder was calculated. considering the skin friction. The attitude angle and Sommerfeld reciprocal are decreased with eccentricity. Viscous damping coefficient due to the skin friction becomes larger with decreasing the annular space. It is found the non-linear effects of the convection terms on the flow and the load are important. especially on the attitude angle, for relatively wide annular configurations however, the effects on those are minor for very narrow annular ones.