期刊文献+
共找到11篇文章
< 1 >
每页显示 20 50 100
Performance Analysis of Optimization Based FOC and DTC Methods for Three Phase Induction Motor 被引量:1
1
作者 V.Jesus Bobin M.MarsalineBeno 《Intelligent Automation & Soft Computing》 SCIE 2023年第2期2493-2511,共19页
Three-phase induction motors are becoming increasingly utilized in industrialfield due to their better efficiency and simple manufacture.The speed control of an induction motor is essential in a variety of applications,... Three-phase induction motors are becoming increasingly utilized in industrialfield due to their better efficiency and simple manufacture.The speed control of an induction motor is essential in a variety of applications,but it is dif-ficult to control.This research analyses the three-phase induction motor’s perfor-mance usingfield-oriented control(FOC)and direct torque control(DTC)techniques.The major aim of this work is to provide a critical evaluation of devel-oping a simple speed controller for induction motors with improving the perfor-mance of Induction Motor(IM).For controlling a motor,different optimization approaches are accessible;in this research,a Fuzzy Logic Controller(FLC)with Fractional Order Darwinian Particle Swarm Optimization(FODPSO)algorithm is presented to control the induction motor.The FOC and DTC are controlled using FODPSO,and their performance is compared to the traditional FOC and DTC technique.Each scheme had its own simulation model,and the results were com-pared using hardware experimental and MATLAB-Simulink.In terms of time domain specifications and torque improvement,the proposed technique surpasses the existing method. 展开更多
关键词 Three-phase induction motor fractional order darwinian particle swarm optimization speed control field-oriented control direct torque control fuzzy logic controller
下载PDF
Reduced differential transform and Sumudu transform methods for solving fractional financial models of awareness
2
作者 A.M.S.Mahdy K.A.Gepreel +1 位作者 Kh.Lotfy A.El-Bary 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第3期338-356,共19页
In that paper,we new study has been carried out on previous studies of one of the most important mathematical models that describe the global economic movement,and that is described as a non-linear fractional financia... In that paper,we new study has been carried out on previous studies of one of the most important mathematical models that describe the global economic movement,and that is described as a non-linear fractional financial model of awareness,where the studies are represented at the steps following:One:The schematic of the model is suggested.Two:The disease-free equilibrium point(DFE)and the stability of the equilibrium point are discussed.Three:The stability of the model is fulfilled by drawing the Lyapunov exponents and Poincare map.Fourth:The existence of uniformly stable solutions have discussed.Five:The Caputo is described as the fractional derivative.Six:Fractional optimal control for NFFMA is discussed by clarifying the fractional optimal control through drawing before and after control.Seven:Reduced differential transform method(RDTM)and Sumudu Decomposition Method(SDM)are used to take the resolution of an NFFMA.Finally,we display that SDM and RDTM are highly identical. 展开更多
关键词 financial of awareness stability Lyapunov exponents Poincare map fractional optimal control HAMILTONIAN
下载PDF
SAR target detection based on the optimal fractional Gabor spectrum feature
3
作者 Ling-Bing Peng Yu-Qing Wang +1 位作者 Ying-Pin Chen Zhen-Ming Peng 《Journal of Electronic Science and Technology》 EI CAS CSCD 2023年第2期55-64,共10页
In this paper,an algorithm based on a fractional time-frequency spectrum feature is proposed to improve the accuracy of synthetic aperture radar(SAR)target detection.By extending the fractional Gabor transform(FrGT)in... In this paper,an algorithm based on a fractional time-frequency spectrum feature is proposed to improve the accuracy of synthetic aperture radar(SAR)target detection.By extending the fractional Gabor transform(FrGT)into two dimensions,the fractional time-frequency spectrum feature of an image can be obtained.In the achievement process,we search for the optimal order and design the optimal window function to accomplish the two-dimensional optimal FrGT.Finally,the energy attenuation gradient(EAG)feature of the optimal time-frequency spectrum is extracted for high-frequency detection.The simulation results show the proposed algorithm has a good performance in SAR target detection and lays the foundation for recognition. 展开更多
关键词 Optimal fractional Gabor transform(FrGT) Optimal order Synthetic aperture radar(SAR)target detection Time-frequency spectrum analysis
下载PDF
Variational Calculus With Conformable Fractional Derivatives 被引量:4
4
作者 Matheus J.Lazo Delfim F.M.Torres 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第2期340-352,共13页
Invariant conditions for conformable fractional problems of the calculus of variations under the presence of external forces in the dynamics are studied. Depending on the type of transformations considered, different ... Invariant conditions for conformable fractional problems of the calculus of variations under the presence of external forces in the dynamics are studied. Depending on the type of transformations considered, different necessary conditions of invariance are obtained. As particular cases, we prove fractional versions of Noether's symmetry theorem. Invariant conditions for fractional optimal control problems, using the Hamiltonian formalism, are also investigated. As an example of potential application in Physics, we show that with conformable derivatives it is possible to formulate an Action Principle for particles under frictional forces that is far simpler than the one obtained with classical fractional derivatives. 展开更多
关键词 Conformable fractional derivative fractional calculus of variations fractional optimal control invariant variational conditions Noether’s theorem
下载PDF
Isolation of Cordyceps ophioglossoides L2 from Fruit Body and Optimization of Fermentation Conditions for Its Mycelial Growth 被引量:6
5
作者 许勤勤 吕龙贤 +3 位作者 陈少云 郑静 郑高利 李永泉 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第2期278-285,共8页
A strain isolated from the fruiting body of a fungus parasitized on Elaphomyces was identified as Cordyceps ophioglossoides based on the morphological characteristics and the analysis of ITS-5.8s rDNA sequence. The op... A strain isolated from the fruiting body of a fungus parasitized on Elaphomyces was identified as Cordyceps ophioglossoides based on the morphological characteristics and the analysis of ITS-5.8s rDNA sequence. The optimal medium, composition (g·L^-1), containing sucrose 66.0, yeast powder 10.0, silkworm chrysalises digest 30.0, MgSO4· 7H2O 0.4, and KH2PO4 0.4, Was found using fractional factorial design ancl a central composite design, and the optimization of cultural conditions obtained a result of seed age 6 days, inoculum size 6% (by volume), initial pH 5.6, temperature 24℃, shaking speed 160 ·'min^-1 by one-factor-at-a-time method. The maximum biomass reached about 20.2 g·L^-1 after 90 hours culture under the optimal conditions. Elementary nharmaeclogical actlwtties showed that mycelia of C. ophioglossoides L2 from submerged culture promoted Uterus growth in estrogen- depleted mice. In the 15-litre scale-up fermentation, the mycelial biomass was around 19.1 g·L^-1, indicating a promising prospect for this biotechnoloagy and the potency to develoo its medical value. 展开更多
关键词 Cordyceps ophioglossoides identification fermentation optimization fractional factorial design central composite design
下载PDF
Convergence and Superconvergence of Fully Discrete Finite Element for Time Fractional Optimal Control Problems 被引量:1
6
作者 Yuelong Tang 《American Journal of Computational Mathematics》 2021年第1期53-63,共11页
In this paper, we consider a fully discrete finite element approximation for time fractional optimal control problems. The state and adjoint state are approximated by triangular linear fi nite elements in space and &l... In this paper, we consider a fully discrete finite element approximation for time fractional optimal control problems. The state and adjoint state are approximated by triangular linear fi nite elements in space and <em>L</em>1 scheme in time. The control is obtained by the variational discretization technique. The main purpose of this work is to derive the convergence and superconvergence. A numerical example is presented to validate our theoretical results. 展开更多
关键词 Time fractional Optimal Control Problems Finite Element Convergence and Superconvergence
下载PDF
Fractional Order Darwinian Pigeon-Inspired Optimization for Multi-UAV Swarm Controller 被引量:2
7
作者 Bingda Tong Chen Wei Yuhui Shi 《Guidance, Navigation and Control》 2022年第2期80-98,共19页
This paper presents a novel multiple unmanned aerial vehicde(UAV)swarm cotoller based on the fractional alculus theory.This controller i designed baed on fractional order Darwinian pigeon-inepired optimization(F 0DPI0... This paper presents a novel multiple unmanned aerial vehicde(UAV)swarm cotoller based on the fractional alculus theory.This controller i designed baed on fractional order Darwinian pigeon-inepired optimization(F 0DPI0)and PID algorithm.Several comparative simulations are conducted in the paper.The simulation results reveal that FODPIObased muli-UAV formation controller is superior to the basic PIO and dilTerential evolution(DE)method.The fractional oelfcdent in F ODPIO algorithm makes it eflective optimbation with fast convergence rate,small oversboot,and better stability.Therefore,the contnoller propoeed in this paper is fessible and robust. 展开更多
关键词 Pigeon-inspired optimization(PIO) fractional order Darwinian pigeon-inspired optimization(FODPIO) unmanned aerial vehicle(UAV) formation control
原文传递
A Priori Error Estimates for Spectral Galerkin Approximations of Integral State-Constrained Fractional Optimal Control Problems
8
作者 Juan Zhang Jiabin Song Huanzhen Chen 《Advances in Applied Mathematics and Mechanics》 SCIE 2023年第3期568-582,共15页
The fractional optimal control problem leads to significantly increased computational complexity compared to the corresponding classical integer-order optimal control problem,due to the global properties of fractional... The fractional optimal control problem leads to significantly increased computational complexity compared to the corresponding classical integer-order optimal control problem,due to the global properties of fractional differential operators.In this paper,we focus on an optimal control problem governed by fractional differential equations with an integral constraint on the state variable.By the proposed first-order optimality condition consisting of a Lagrange multiplier,we design a spectral Galerkin discrete scheme with weighted orthogonal Jacobi polynomials to approximate the resulting state and adjoint state equations.Furthermore,a priori error estimates for state,adjoint state and control variables are discussed in details.Illustrative numerical tests are given to demonstrate the validity and applicability of our proposed approximations and theoretical results. 展开更多
关键词 fractional optimal control problem state constraint spectral method Jacobi polynomial a priori error estimate
原文传递
MINIMIZING A LINEAR FRACTIONAL FUNCTION SUBJECT TO A SYSTEM OF SUP-T EQUATIONS WITH A CONTINUOUS ARCHIMEDEAN TRIANGULAR NORM 被引量:1
9
作者 Pingke LI Edward P.Fitts Department of Industrial and Systems Engineering,North Carolina State University,Raleigh,NC 27695-7906,US Shu-Cherng FANG Edward P.Fitts Department of Industrial and Systems Engineering,North Carolina State University,Raleigh,NC 27695-7906,USA Department of Mathematical Sciences,Tsinghua University,Beijing 100084,China College of Management,Dalian University of Technology,Dalian 116024,China. 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2009年第1期49-62,共14页
This paper shows that the problem of minimizing a linear fractional function subject to asystem of sup-T equations with a continuous Archimedean triangular norm T can be reduced to a 0-1linear fractional optimization ... This paper shows that the problem of minimizing a linear fractional function subject to asystem of sup-T equations with a continuous Archimedean triangular norm T can be reduced to a 0-1linear fractional optimization problem in polynomial time.Consequently,parametrization techniques,e.g.,Dinkelbach's algorithm,can be applied by solving a classical set covering problem in each iteration.Similar reduction can also be performed on the sup-T equation constrained optimization problems withan objective function being monotone in each variable separately.This method could be extended aswell to the case in which the triangular norm is non-Archimedean. 展开更多
关键词 fractional optimization fuzzy relational equations triangular norms.
原文传递
Global stability and optim al control of a two-patch tuberculosis epidemic model using fractional-order derivatives 被引量:1
10
作者 Hossein Kheiri Mohsen Jafari 《International Journal of Biomathematics》 SCIE 2020年第3期1-27,共27页
In this paper,we propose a fractional-order and two-patch model of tuberculosis(TB)epidemic,in which susceptible,slow latent,fast latent and infectious individuals can travel freely between the patches,but not under t... In this paper,we propose a fractional-order and two-patch model of tuberculosis(TB)epidemic,in which susceptible,slow latent,fast latent and infectious individuals can travel freely between the patches,but not under treatment infected individuals,due to medical reasons.We obtain the basic reproduction number Ro for the model and extend the classical LaSalle's invariance principle for fractional differential equations.We show that if R0<1,the disease-free equilibrium(DFE)is locally and globally asymptotically stable.If Ro>l,we obtain sufficient conditions under which the endernic equilibrium is unique and globally asymptotically stable.We extend the model by inclusion the time-dependent controls(effective treatment controls in both patches and controls of screening on travel of infectious individuals between patches),and formulate a fractional optimal control problem to reduce the spread of the disease.The numerical results show that the use of all controls has the most impact on disease control,and decreases the size of all infected compartments,but increases the size of susceptible compartment in both patches.We,also,investigate the impact of the fractional derivative order a on the values of the controls(0.7≤α≤1).The results show that the maximum levels of effective treatment controls in both patches increase when a is reduced from l,while the maximum level of the travel screening control of infectious individuals from patch 2 to patch 1 increases when o limits to 1. 展开更多
关键词 Patch models fractional optimal control global stability tuberculosis epidemic
原文传递
Comparative studies for the fractional optimal control in transmission dynamics of West Nile virus
11
作者 N. H. Sweilam O.M.Saad D. G. Mohamed 《International Journal of Biomathematics》 2017年第7期75-105,共31页
In this paper, optimal control for a novel West Nile virus (WNV) model of fractional order derivative is presented. The proposed model is governed by a system of fractional differential equations (FDEs), where the... In this paper, optimal control for a novel West Nile virus (WNV) model of fractional order derivative is presented. The proposed model is governed by a system of fractional differential equations (FDEs), where the fractional derivative is defined in the Caputo sense. An optimal control problem is formulated and studied theoretically using the Pon- tryagin maximum principle. Two numerical methods are used to study the fractional- order optimal control problem. The methods are, the iterative optimal control method (OCM) and the generalized Euler method (GEM). Positivity, boundedness and conver- gence of the IOCM are studied. Comparative studies between the proposed methods are implemented, it is found that the IOCM is better than the GEM. 展开更多
关键词 West Nile virus fractional optimal control generalized Euler method Caputo's fractional derivative Griinwald-Letnikovs definition iterative optimal controlmethod Pontryagin's maximum principle.
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部