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ADAPTIVE EXPONENT SMOOTHING gradient algorithm

Transactions of Nanjing University of Aeronautics and Astronautics 1997年第1期14卷 25-31页

作者：裴炳南李传光郑州大学电子工程系北京理工大学自动控制系

A new algorithm, called the adaptive exponent smoothing gradient algorithm (AESGA), is developed from Widrow′s LMS algorithm. It is based on the fact that LMS algorithm has properties of time delaying and low pass filtering. This paper shows that the algorithm, on the domain of {Ω 1:α∈(0,1)}×{Ω 2:β(0,∞)} , unbiasedly and asymptotically converges to the Winner solution when the signal is a stationary Gauss stochastic process. The convergent property and the performance misadjustment are analyzed in theory. And calculation method of the algorithm is also suggested. Numerical results given by computer simulations show that the algorithm is effective.

关键词： signal processing adaptive filtering gradient algorithm LMS algorithm computer simulation

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Fast gradient descent algorithm for image classification with neural networks

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SIGNAL IMAGE AND VIDEO PROCESSING 2020年第8期14卷 1565-1572页

作者： El Mouatasim, Abdelkrim Ibn Zohr Univ FPO BP 284 Ouarzazate 45800 Morocco

Any optimization of gradient descent methods involves selecting a learning rate. Tuning the learning rate can quickly become repetitive with deeper models of image classification, does not necessarily lead to optimal convergence. We proposed in this paper, a modification of the gradient descent algorithm in which the Nestrove step is added, and the learning rate is update in each epoch. Instead, we learn learning rate itself, either by Armijo rule, or by control step. Our algorithm called fast gradient descent (FGD) for solving image classification with neural networks problems, the quadratic convergence rate o(k(2)) of FGD algorithm are proved. FGD algorithm are applicate to a MNIST dataset. The numerical experiment, show that our approach FGD algorithm is faster than gradient descent algorithms.

关键词： gradient algorithm Nesterov algorithm Learning rate control Image classification Neural networks

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Multi-step-length gradient iterative algorithm for equation-error type models

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SYSTEMS & CONTROL LETTERS 2018年 115卷 15-21页

作者： Chen, Jing Ding, Feng Liu, Yanjun Zhu, Quanmin Jiangnan Univ Minist Educ Key Lab Adv Proc Control Light Ind Wuxi 214122 Peoples R China Univ West England Dept Engn Design & Math Bristol BS16 1QY Avon England

This letter develops a multi-step-length gradient iterative algorithm for equation-error type (EET) models. The algorithm analysis is based upon the gradient search principle. By applying the Gram-Schmidt procedure, the EET model can be turned into an orthogonal model, in which each parameter in the parameter vector is independent of the other parameters. Then a multi-step-length gradient iterative algorithm is proposed for the orthogonal model, and can estimate the parameters in one iteration. Finally, based on the estimated parameters, the parameter estimates of the EET model can be computed. Different from the traditional gradient iterative algorithm which has slower convergence rates and is sensitive to the initial values of the unknown variables, the method in this letter has quicker convergence rates and is robust to the initial values of the unknown variables. The simulation studies demonstrate the feasibility and effectiveness of the proposed algorithm. (C) 2018 Elsevier B.V. All rights reserved.

关键词： Parameter estimation gradient algorithm Multi-step-length Convergence rate EET model

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Adaptive gradient Search algorithm for Displaced Subarrays With Large Element Spacing

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IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS 2021年第7期20卷 1155-1159页

作者： Yang, Gongqing Zeng, Hui Xu, Zhenhai Natl Univ Def Technol State Key Lab Complex Elect Environm Effects Elec Informat Syst Changsha 410073 Peoples R China

In this letter, an adaptive gradient search algorithm for displaced subarray optimization is presented. The displaced subarray technique, which is able to suppress the high grating lobes caused by large interelement spacing (i.e., over one-half wavelength), has attracted much attention. In this case, it could reduce the number of active elements as well as the cost of conventional phased array antennas. However, the optimal solution of each displaced subarray location is hard to achieve. The proposed algorithm is a practical method to solve such a nonconvex problem. By gradually reducing the iteration step size, when the search times of each step are enough, the solution is able to converge to a satisfying solution. The effectiveness and the stable performance of our proposed method are verified by various numerical examples.

关键词： Optimized production technology Apertures Gratings Antenna radiation patterns Phased arrays Upper bound Shape Aperture efficiency displaced subarrays gradient algorithm grating lobe (GL) suppression

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Thermo-Economic Optimization of Spiral Plate HX by Means of gradient and gradient-Free algorithm

Thermo-Economic Optimization of Spiral Plate HX by Means of ...

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International Conference on Advancement in Materials, Manufacturing and Energy Engineering (ICAMME)

作者： Krishna, Musunuru Hari Dasore, Abhishek Rajak, Upendra Konijeti, Ramakrishna Verma, Tikendra Nath SRK Inst Technol Dept Mech Engn Vijayawada 521108 India RGM Coll Engn & Technol Sch Mech Engn Nandyal 518501 India Koneru Lakshmaiah Educ Fdn Dept Mech Engn Guntur 522502 Andhra Pradesh India Maulana Azad Natl Inst Technol Dept Mech Engn Bhopal 462003 India

ISBN: (纸本)9789811683411;9789811683404

Spiral plate heat exchangers (SPHX) play prominent role in process industries with the fact that rotational motion of the fluid in the channel eliminates the occurrence of fouling. In the present study, thermo-economic optimization of SPHX was performed considering the standard Hall equation as the objective function. For a specified heat duty design, parameters, namely pressure drop in hot and cold fluids, outer spiral diameter, plate length and plate width, are optimized with the objective of minimized cost, using gradient (fmincon) and gradient-free (genetic algorithm (GA)) optimization algorithms. The outcomes were compared to the data attained from experimental works found in the literature. It was found that GA outperforms fmincon in terms of cost minimization. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.

关键词： gradient algorithm gradient-free algorithm Maximization Spiral plate heat exchanger Thermo-economics

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Reconstruction of Global Ozone Density Data using a gradient-Descent algorithm 58

Reconstruction of Global Ozone Density Data using a Gradient...

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58th ELMAR International Symposium

作者： Stankovic, Isidora Dai, Wei Univ Montenegro Fac Elect Engn Podgorica 20000 Montenegro Imperial Coll London Dept Elect & Elect Engn London SW7 2AZ England

ISBN: (纸本)9789531842211

The Ozone density and its decrease in the atmo-sphere are one of the main concerns of nowadays. The Ozone density is tracked using the Ozone Measurements Instrument (OMI). During tracking and collection of information, missing data occur because of the pathway the instrument is going. Reconstruction of those missing data can be done using the results from the compressive sensing (CS) approach. The application of a CS algorithm based on the gradient-descent method for the Ozone density data reconstruction is presented in this paper. The algorithm is based on varying the missing data to promote sparsity in each frame. The algorithm is modified for a more efficient reconstruction by using the dynamic information about previous frames. The reconstruction results for some recent Ozone data are presented.

关键词： Compressive Sensing Ozone Data gradient algorithm Reconstruction

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gradient-Descent algorithm Performance With Reduced Set of Quantized Measurements 8

Gradient-Descent Algorithm Performance With Reduced Set of Q...

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8th Mediterranean Conference on Embedded Computing (MECO)

作者： Stankovic, Isidora Brajovic, Milos Dakovic, Milos Ioana, Cornel Univ Montenegro Fac Elect Engn Podgorica Montenegro Univ Grenoble Alpes GIPSA Lab Grenoble France

ISBN: (纸本)9781728117393

The quantization (digitalization) of measurements greatly affects the reconstruction performance, especially in algorithms based on the reconstruction in the measurement domain. However, it provides a significant advantage in the hardware implementation sense. In this paper, we analyze the performance of the gradient-based algorithm in the signal reconstruction based on a reduced set of digital measurements. This algorithm is considered as a powerful tool for the reconstruction of various types of signals. The paper investigates the accuracy of the algorithm using B-bit quantized measurements. The reconstruction performance is analyzed through numerical examples.

关键词： compressive sensing quantization reconstruction sparse signal processing gradient algorithm

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gradient APPROXIMATION algorithmS FOR THE σ-OSS plus CONCAVE FUNCTION MAXIMIZATION

JOURNAL OF NONLINEAR AND VARIATIONAL ANALYSIS

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JOURNAL OF NONLINEAR AND VARIATIONAL ANALYSIS 2025年第1期9卷 15-30页

作者： Zhang, Hongxiang Yang, Wenguo Du, Ding-zhu Univ Chinese Acad Sci Sch Math Sci Beijing 100049 Peoples R China Univ Texas Dallas Dept Comp Sci Dallas TX 75083 USA

This paper studies the one-sided sigma-smooth + concave function maximization problems under general convex sets. Provided that the objective function is Lipschitz smooth, we use the jump-start initial point selection technique and the Frank-Wolfe method to propose a [1 - e-(1-alpha)eta-1], [1 - e-(1-alpha)eta-1] approximation algorithm with O(epsilon-1(n + T)) time complexity, where eta = ( alpha+1)2 sigma, alpha E (0,1), and sigma is a finite constant. The algorithm is discrete-time and receives O losses. To overcome the disadvantage that the gradient of function is Lipschitz continuous, we propose the continuous-time JumpStart Greedy Frank-Wolfe algorithm with the same approximation guarantee. In addition, through the analysis of our algorithms, we investigate some important theoretical properties regarding the analysis of approximation algorithms for continuous function maximization problems.

关键词： . Approximation algorithm Continuous function maximization problem Frank-Wolfe method gradient algorithm OSS plus concave

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Robust adaptive control for nonlinear discrete-time systems based on DE-GMAW

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CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS 2025年 256卷

作者： Wang, Jing Tian, Engang Yan, Huaicheng Qu, Fanrong Univ Shanghai Sci & Technol Sch Opt Elect & Comp Engn Shanghai 200093 Peoples R China East China Univ Sci & Technol Informat Sci & Engn Shanghai 200093 Peoples R China Huazhong Univ Sci & Technol Sch Artificial Intelligence & Automat Wuhan Peoples R China

Gas Metal Arc Welding (GMAW) is a critical process in manufacturing, known for its efficiency and versatility. The double-electrode GMAW (DE-GMAW) technique further enhances these attributes, offering superior welding speed and improved melting effects. However, controlling the DE-GMAW process effectively remains a complex challenge due to the nonlinear and dynamic nature of the system. The process involves intricate interactions between electrical, thermal, and mechanical phenomena, resulting in highly nonlinear behavior. Variations in material properties, environmental conditions, and external disturbances can adversely affect the welding process. Moreover, traditional control methods often fail to account for unmodeled dynamics and modeling errors, leading to performance degradation and potential instability. To address these challenges, this paper introduces a robust adaptive control scheme tailored for DE-GMAW systems, which combines online projection estimation identification and pole placement strategy at the same time to compensate for parameter uncertainties, external disturbances, and unmodeled dynamics. Simulation examples in welding process are carried out to demonstrate the effectiveness of the proposed robust adaptive control scheme.

关键词： Robust adaptive control scheme Nonlinear system gradient algorithm Pole assignment self-tuning Double-electrode gas metal arc welding (DE-GMAW)

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A numerical study of vortex nucleation in 2D rotating Bose-Einstein condensates

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MATHEMATICS AND COMPUTERS IN SIMULATION 2025年 229卷 409-434页

作者： Dujardin, Guillaume Lacroix-Violet, Ingrid Nahas, Anthony Univ Lille Inria CNRS UMR 8524 Lab Paul Painleve F-59000 Lille France Univ Lorraine CNRS IECL F-54000 Nancy France Univ Lille CNRS UMR 8524 InriaLab Paul Painleve F-59000 Lille France

This article implements a numerical method for the minimization under constraints of a discrete energy modelling multicomponents rotating Bose-Einstein condensates in the regime of strong confinement and with rotation. Moreover, this method allows to consider both segregation and coexistence regimes between the components. The method includes a discretization of a continuous energy in space dimension 2 and a gradient algorithm with adaptive time step and projection for the minimization. It is well known that, depending on the regime, the minimizers may display different structures, sometimes with vorticity (from singly quantized vortices, to vortex sheets and giant holes). The goal of this paper is to study numerically the structures of the minimizers. In order to do so, we introduce a numerical algorithm for the computation of the indices of the vortices, as well as an algorithm for the computation of the indices of vortex sheets. Several computations are carried out, to illustrate the efficiency of the method, to cover different physical cases, to validate recent theoretical results as well as to support conjectures. Moreover, we compare this method with an alternative method from the literature.

关键词： Bose-Einstein condensation Gross-Pitaevskii energy Segregation and coexistence regimes Minimization under constraints gradient algorithm Vortex detection Vortex quantization Numerical experiments

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