This paper is concerned with developing an efficient regularized smoothing newton-type algorithm for quasi-variational inequalities. The proposed algorithm takes the advantage of newly introduced smoothing functions a...
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This paper is concerned with developing an efficient regularized smoothing newton-type algorithm for quasi-variational inequalities. The proposed algorithm takes the advantage of newly introduced smoothing functions and a non-monotone line search strategy. It is proved to be globally and locally superlinearly/quadratically convergent under suitable assumptions. Numerical results demonstrate that the algorithm generally outperforms the existing interior point method and semismooth method (Facchinei, et al. 2014). (C) 2014 Elsevier Ltd. All rights reserved.
A new Wide-Area Monitoring System (WAMS) application for monitoring inter-area oscillations, based on the newton-type algorithm is presented in this paper. The core of this novel WAMS application is a numerical algori...
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A new Wide-Area Monitoring System (WAMS) application for monitoring inter-area oscillations, based on the newton-type algorithm is presented in this paper. The core of this novel WAMS application is a numerical algorithm for the real-time estimation of the dominant inter-area oscillation mode, which processes Global Positioning System synchronized information obtained from Phasor Measurement Units installed in the power system. The parameter model is a highly nonlinear function, making this a particularly difficult challenge. Two data sets were tested using the new algorithm, one based on simulated models and the other based on real-life data records. The computer simulated model was based on a known architecture with signals obtained using a dynamic simulation of a multi-machine power system. The real-life data records used information collected on the FlexNet Wide-Area Monitoring System (FlexNET-WAMS) installed in the Great Britain power grid. Copyright (c) 2016 John Wiley & Sons, Ltd.
In this paper, the subspace properties of trust-region methods are employed to develop a regularized newton-type (RNT) algorithm for solving convex optimization problem. The proposed RNT algorithm is analyzed for quad...
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In this paper, the subspace properties of trust-region methods are employed to develop a regularized newton-type (RNT) algorithm for solving convex optimization problem. The proposed RNT algorithm is analyzed for quadratic convergence under the local error bound conditions and global convergence for unconstrained convex optimization problems which may have singular Hessian at the solutions. Afterwards numerical results are presented to show the efficiency and robustness of the proposed algorithm in producing an optimal solution for the given problem.
in this paper, the generalized linear complementarity problem over a polyhedral cone (GLCP) is reformulated as an unconstrained optimization, based on which we propose a newton-type algorithm to solve it. Under certai...
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in this paper, the generalized linear complementarity problem over a polyhedral cone (GLCP) is reformulated as an unconstrained optimization, based on which we propose a newton-type algorithm to solve it. Under certain conditions, we show that the algorithrn converges globally and quadratically. Preliminary numerical experiments are also reported in this paper. (c) 2004 Elsevier Inc. All rights reserved.
In this paper, we propose an adaptive algorithm using newton's method for the enhancement of EEG signals in the presence of EOG artefacts. We consider two models for the noise (i.e., artefacts) estimation: (i) the...
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In this paper, we propose an adaptive algorithm using newton's method for the enhancement of EEG signals in the presence of EOG artefacts. We consider two models for the noise (i.e., artefacts) estimation: (i) the conventional linear model and (ii) a nonlinear model using second-order Volterra function. Application of newton's method to the linear case results in the conventional recursive least-squares algorithm. Since the parameters of the nonlinear model are specified in terms of a vector and a matrix, the conventional newton's method could not be applied. Hence, the underlying cost function has been reformulated whereby all the parameters are represented by a single vector and then newton's method is applied to this reformulated cost function. While developing the algorithm for the nonlinear case, the Hessian matrix is approximated because of the special property of the reference signal. This ensures the reduced computational complexity and positive definiteness of the approximated Hessian so as to ensure search along the descent directions. Another algorithm making use of the exact Hessian matrix is also derived. These algorithms were used to minimize the EOG artefacts from EEG signals. Simulation results show that the nonlinear scheme with approximated Hessian works well compared to the other two algorithms in minimizing EOG artefacts from contaminated EEG signals. (C) 1997 Published by Elsevier Science B.V.
The paper reports new software developments for symmetrical components estimation. Nonrecursive newton-type algorithm is extended with the second stage algorithm for symmetrical components calculation from the estimat...
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The paper reports new software developments for symmetrical components estimation. Nonrecursive newton-type algorithm is extended with the second stage algorithm for symmetrical components calculation from the estimated fundamental phasors of three-phase signals (arbitrary voltages or currents). The algorithm is not sensitive to power system frequency changes and to the harmonic distortion of input signals. The algorithm is tested through computer simulations and by using laboratory obtained input signals and those recorded in the real distribution network.
We propose a novel and fast algorithm to train support vector machines (SVMs) in primal space, which solves an approximate optimization of SVMs with the properties of unconstraint, continuity and twice differentiabili...
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We propose a novel and fast algorithm to train support vector machines (SVMs) in primal space, which solves an approximate optimization of SVMs with the properties of unconstraint, continuity and twice differentiability by utilizing the newton optimization technique. Further, we devise a special pre-extracting procedure to speed up the convergence of the algorithm by resorting to a high-quality initial solution. Theoretical studies show that the proposed algorithm produces an e-approximate solution to standard SVMs and maintains low computational complexity. Experimental results on benchmark data sets demonstrate that our algorithm is much faster than the dual based method such as SVMlight while it achieves the similar test accuracy. (c) 2006 Elsevier B.V. All rights reserved.
Introduction: When a study sample includes a large proportion of long-term survivors, mixture cure (MC) models that separately assess biomarker associations with long-term recurrence-free survival and time to disease ...
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Introduction: When a study sample includes a large proportion of long-term survivors, mixture cure (MC) models that separately assess biomarker associations with long-term recurrence-free survival and time to disease recurrence are preferred to proportional-hazards models. However, in samples with few recurrences, standard maximum likelihood can be *** and Methods: We extend Firth-type penalized likelihood (FT-PL) developed for bias reduction in the exponential family to the Weibull-logistic MC, using the Jeffreys invariant prior. Via simulation studies based on a motivating cohort study, we compare parameter estimates of the FT-PL method to those by ML, as well as type 1 error (T1E) and power obtained using likelihood ratio ***: In samples with relatively few events, the Firth-type penalized likelihood estimates (FT-PLEs) have mean bias closer to zero and smaller mean squared error than maximum likelihood estimates (MLEs), and can be obtained in samples where the MLEs are infinite. Under similar T1E rates, FT-PL consistently exhibits higher statistical power than ML in samples with few events. In addition, we compare FT-PL estimation with two other penalization methods (a log-F prior method and a modified Firth-type method) based on the same ***: Consistent with findings for logistic and Cox regressions, FT-PL under MC regression yields finite estimates under stringent conditions, and better bias-and-variance balance than the other two penalizations. The practicality and strength of FT-PL for MC analysis is illustrated in a cohort study of breast cancer prognosis with long-term follow-up for recurrence-free survival.
The parameters of a hidden Markov model (HMM) can be estimated by numerical maximization of the log-likelihood function or, more popularly, using the expectation-maximization (EM) algorithm. In its standard implementa...
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The parameters of a hidden Markov model (HMM) can be estimated by numerical maximization of the log-likelihood function or, more popularly, using the expectation-maximization (EM) algorithm. In its standard implementation the latter is unsuitable for fitting stationary hidden Markov models (HMMs). We show how it can be modified to achieve this. We propose a hybrid algorithm that is designed to combine the advantageous features of the two algorithms and compare the performance of the three algorithms using simulated data from a designed experiment, and a real data set. The properties investigated are speed of convergence, stability, dependence on initial values, different parameterizations. We also describe the results of an experiment to assess the true coverage probability of bootstrap-based confidence intervals for the parameters.
In this paper, we proposed a novel newton-type solver for one-class support vector machines in the primal space directly. Firstly, utilizing reproducing property of kernel and Huber regression function, original const...
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ISBN:
(纸本)9780769535593
In this paper, we proposed a novel newton-type solver for one-class support vector machines in the primal space directly. Firstly, utilizing reproducing property of kernel and Huber regression function, original constrained quadratic programming is transformed into approximate unconstrained one, which is continuous and twice differentiable. Then, we give a newton-type training algorithm to solve it. Further analysis shows the computation complexity of our algorithm is identical with theoretical lower bound for solving one-class support vector machines. In the end, experiments on 9 UCI datasets are done to validate the effectivity of proposed algorithm, and when comparing with dual method (LIBSVM), its produces comparative testing accuracy, better training speed, and less support vectors.
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