In the real applied optimization problems, we usually face nonlinear fuzzy programmingproblems (FNLPPs). This paper focuses on a class of fuzzy quadratic programming problems (FQPPs) in which all of technical coeffic...
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ISBN:
(纸本)9781665496728
In the real applied optimization problems, we usually face nonlinear fuzzy programmingproblems (FNLPPs). This paper focuses on a class of fuzzy quadratic programming problems (FQPPs) in which all of technical coefficients and constraint inequalities are fuzzy ones. Initially, some definitions of fuzzy mathematics are introduced and then, we discuss on fuzzy quadratic programming problems and introduce a new approach to find the approximate solution to these problems. Finally, we introduce some numerical examples to show the efficiency of the proposed approach.
Inexact quadraticprogramming (IQP) is designed to handle impreciseness in data/modelling parameters of quadraticprogramming (QP). The nature of IQP often leads to procedural and applicability problems. The existing ...
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Inexact quadraticprogramming (IQP) is designed to handle impreciseness in data/modelling parameters of quadraticprogramming (QP). The nature of IQP often leads to procedural and applicability problems. The existing studies on IQP have not incorporated the terms of the type x(i)x(j), i not equal j in the formulation of IQP problem (or IQPP), thereby limiting its scope of applications to specific types of problems only. The paper presents an extension of the past efforts by including such terms and hence, gives wider scope of its applications. Two methodologies viz. Duality approach and Modified method to solve the generalized IQPP are suggested. In addition, it has been shown that the Modified method significantly increases the computational efficiency by reducing the involved variables and constraints. Finally, an application of IQP is demonstrated by citing a realistic problem from an area of product mix and production planning, particularly in the tea industry.
This article deals with some properties of the global minimizer set G(Q), the local minimizer set L-Q, and the stationary point set S-Q to the quadratic programming problem (Q) of minimizing the function f(x) =(1/2)x(...
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This article deals with some properties of the global minimizer set G(Q), the local minimizer set L-Q, and the stationary point set S-Q to the quadratic programming problem (Q) of minimizing the function f(x) =(1/2)x(T)Ax + b(T)x on the polyhedron D = {x is an element of R-n vertical bar C(i)x >= d(i), i is an element of I}, where A is an element of R-nxn, b is an element of R-n, d is an element of R-m, C-i(T) is an element of R-n, i is an element of I = {1, 2, ..., m}. In particular, we investigate the intersection of these solution sets with faces (D) over bar (J) = {x is an element of R-n vertical bar C(i)x >= d(i) for i is an element of J, C(i)x >= d(i) for i is an element of I\J} and pseudofaces D-J = {x is an element of R-n vertical bar C(i)x >= d(i) for i is an element of J, C(i)x = d(i) for i is an element of I\J}, where J subset of I. Some selected results are the following. If G(Q) boolean AND D-J not equal 0 then G(Q) boolean AND D-J and G(Q) boolean AND (D) over bar (J) are relatively affine in the following sense: G(Q) boolean AND D-J = aff(G(Q) boolean AND D-J) boolean AND D-J and G(Q) boolean AND (D) over bar (J) = aff(G(Q) boolean AND (D) over bar (J)) boolean AND D. If L-Q boolean AND D-J not equal 0 then L-Q boolean AND D-J is open relative to aff(L-Q boolean AND (D) over bar (J)) boolean AND D-J, L-Q boolean AND (D) over bar (J) is open relative to aff(L-Q boolean AND (D) over bar (J)) boolean AND D-J and L-Q boolean AND (D) over bar (J) are convex. If G(Q) boolean AND D-J not equal 0 then each stationary point (in particular, each local minimizer) in (D) over bar (J) is a global minimizer. If x(0) is an element of L-Q boolean AND D-J, x(1) is an element of S-Q boolean AND (D) over bar (J), and x(0) not equal x(1), then [x(0), x(1)) subset of L-Q boolean AND D-J subset of L-Q. Let B-m,B-n and C-m,C-n denote the maximal number of nonempty faces and the maximal cardinality of an antichain of nonempty faces of a polyhedron defined as intersection of
The problem of optimising the structure of the encoder/decoder pair in a discrete communication system, with an additive distortion measure, is formulated in terms of a quadraticprogramming (QP) problem. This new for...
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The problem of optimising the structure of the encoder/decoder pair in a discrete communication system, with an additive distortion measure, is formulated in terms of a quadraticprogramming (QP) problem. This new formulation benefits from the following special features: it optimises the joint effects of the source/channel coding on the end-to-end distortion;and the encoder and the decoder structures are not restricted to being the inverse of each other. A method which obtains an epsilon-minimiser approximation of an optimum point of a general QP problem is discussed. Some simulation results based on this method are also given.
This study proposes a novel and efficient dual regression model for possibilistic regression analysis that incorporates the principles of support vector machine (SVM) theory. The dual regression model, which comprises...
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This study proposes a novel and efficient dual regression model for possibilistic regression analysis that incorporates the principles of support vector machine (SVM) theory. The dual regression model, which comprises an upper model and a lower model, approximates the observed fuzzy phenomena from the outside and inside directions, respectively, such that the inclusion relationship between those two models holds. The proposed dual regression model better explains the inherent vagueness that exists in a given dataset. It provides the outer and inner bounds for the estimated vagueness region, and allows an estimation of the degree of confidence in the predicted fuzzy output. Using the principles for a twin support vector machine (TSVM), the upper- and lower models are estimated by solving two smaller SVM-type quadratic programming problems (QPPs), instead of a single larger QPP. This strategy significantly increases the learning speed for the proposed algorithm. The structural risk minimization principle of SVM makes the proposed method to yield better generalization ability. The kernel function method offers a model-independent framework for the proposed dual regression model. This paper focuses on the class of radial kernels, which enables the proposed method to conquer the problem of increasing spreads. The radial kernel also gives the proposed method a unified framework that allows both crisp and fuzzy inputs. The experimental results verify the effectiveness and efficiency of the proposed method. In comparison with previous SVM-based dual regression model, the proposed approach significantly improves the sparsity, prediction speed, and training speed. (C) 2019 Elsevier B.V. All rights reserved.
Temperature control in solar collectors is a nonlinear problem: the dynamics of temperature rise vary according to the fluid flowing through the collector and to the temperature gradient along the collector area. In t...
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Temperature control in solar collectors is a nonlinear problem: the dynamics of temperature rise vary according to the fluid flowing through the collector and to the temperature gradient along the collector area. In this way, this work investigates the formulation of a Model Predictive Control (MPC) application developed within a Linear Parameter Varying (LPV) formalism, which serves as a model of the solar collector process. The proposed system is an adaptive MPC, developed with terminal set constraints and considering the scheduling polytope of the model. At each instant, two quadraticprogramming (QPs) programs are solved: the first considers a backward horizon of N steps to find a virtual model-process tuning variable that defines the best LTI prediction model, considering the vertices of the polytopic system;then, the second QP uses this LTI model to optimize performances along a forward horizon of N steps. The paper ends with a realistic solar collector simulation results, comparing the proposed MPC to other techniques from the literature (linear MPC and robust tube-MPC). Discussions regarding the results, the design procedure and the computational effort for the three methods are presented. It is shown how the proposed MPC design is able to outrank these other standard methods in terms of reference tracking and disturbance rejection.
The next-generation space missions, such as the space moving target tracking mission and the agile attitude maneuvering mission and so on, propose a high requirement on spacecraft attitude control system. For such mis...
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The next-generation space missions, such as the space moving target tracking mission and the agile attitude maneuvering mission and so on, propose a high requirement on spacecraft attitude control system. For such missions, hybrid attitude control actuators consisting of control moment gyro and reaction wheel, which can not only offer large control torque but also achieve high control precision, is the best alternative choice. For this hybrid actuator system, the angular momentum management is vital. To handle the momentum management problem, an optimal angular momentum strategy based on cooperative game theory is proposed. The cooperative game model is constructed according to the quadratic programming problem to achieve the minimization of control moment gyro gimbal angular speed and reaction wheel angular acceleration. The proposed cooperative game theory steering logic has overcome the control moment gyro singular problem and reaction wheel saturation problem of the hybrid system. In addition, the energy cost of the hybrid actuator system is reduced. Five groups of simulation scenarios are carried out to demonstrate the effectiveness of the proposed steering logic.
This study proposes a novel linear time-variant model predictive controller (LTV-MPC) for the centralised control of non-linear standalone micro-grids. At each sample, within the prediction horizon, LTV-MPC linearises...
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This study proposes a novel linear time-variant model predictive controller (LTV-MPC) for the centralised control of non-linear standalone micro-grids. At each sample, within the prediction horizon, LTV-MPC linearises the non-linear micro-grid model around the state and input reference trajectories resulting in a linear time-variant (LTV) model. The LTV model is used for predicting the forced response of the micro-grid. The natural response is predicted by solving the non-linear model along the state and input reference trajectories. An optimal control problem for the LTV-MPC is formulated using the complete predicted response, which is a quadratic programming problem instead of a non-convex non-linear programmingproblem. The quadratic programming problem is solved online at each sample to generate the optimal control trajectories within the control horizon. The study recommends the use of two-parameter orthonormal Kautz networks in the LTV-MPC design for the control trajectories approximation. The approximation drastically reduces the number of optimising variables in the optimal control problem without compromising LTV-MPC performance. A standalone eight bus micro-grid with one synchronous distributed generator (DG) and one photovoltaic-DG is considered for the analysis. The LTV-MPC performance is assessed for the different load disturbance and source intermittency scenarios. The results are compared with the existing MPC designs.
In this study, a generalised minimum variance control (GMVC) method using the projection-based recurrent neural network (PRNN) is proposed to minimise the error variance in the output of the non-linear plant. One the ...
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In this study, a generalised minimum variance control (GMVC) method using the projection-based recurrent neural network (PRNN) is proposed to minimise the error variance in the output of the non-linear plant. One the main drawbacks of the conventional GMVC approaches is the lack of a systematic procedure to deal with the input constraints. In this study, the PRNN is employed for incorporating the input constraints to the minimum variance index. This network is based on the optimality conditions of a constrained problem and is designed using projection theorem. To formulate the proposed approach, by considering an ARMAX model of the system and converting the cost function to a quadratic programming problem, the dynamics and output equations of the PRNN is obtained. The stability and global convergence of the PRNN is analytically shown. Moreover, suitable conditions for the weighting matrices of the cost function are determined to ensure the closed-loop stability. The proposed control method is applied to the non-linear quadruple tank and a comparative analysis between MVC, GMVC and the proposed approach is performed.
Twin-hypersphere support vector machine (THSVM) for binary pattern recognition aims at generating two hyperspheres in the feature space such that each hypersphere contains as many as possible samples in one class and ...
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Twin-hypersphere support vector machine (THSVM) for binary pattern recognition aims at generating two hyperspheres in the feature space such that each hypersphere contains as many as possible samples in one class and is as far as possible from the other one. THSVM has a fast learning speed since it solves two small sized support vector machine (SVM)-type quadratic programming problems (QPPs). However, it only simply considers the prior class-based structural information in the optimization problems. In this paper, a structural information-based THSVM (STHSVM) classifier for binary classification is presented. This proposed STHSVM focuses on the cluster-based structural information of the corresponding class in each optimization problem, which is vital for designing a good classifier in different real-world problems. In addition, it also leads to a fast learning speed since this STHSVM solves a series of smaller-sized QPPs compared with THSVM. Experimental results demonstrate that STHSVM is superior in generalization performance to other classifiers.
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