The paper proposes a new algorithm for solving one class of the tool path problems for CNC sheet cutting machines (the generalized segmental continuous cutting problem, GSCCP) with an additional parameter limited the ...
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ISBN:
(纸本)9783031671944;9783031671951
The paper proposes a new algorithm for solving one class of the tool path problems for CNC sheet cutting machines (the generalized segmental continuous cutting problem, GSCCP) with an additional parameter limited the calculation time for finding an optimal solution. As input data in the GSCCP, 2D layout of nested parts and a finite set of subtasks for optimizing the cutting path are used. Each subtask contains a set of so-called basic cutting segments, which determine the trajectories of tool movement between the points for material piercing and the points for switching tool off. Each subtask can be solved independently within the specified calculation time. The best solution found for the all subtasks is a solution to the GSCCP problem. The proposed iterative algorithm involves quantizing the total computation time. Moreover, within each time quant, all subtasks are also solved sequentially by calculation the upper and lower bounds. Initial upper bounds can, for example, be obtained using any fast heuristic based on effective combinatorial optimization methods. Next, for each of them, the procedure for searching for the lower boundary is launched. The next iteration of the solution process is performed taking into account the adjusted bounds. The solution procedures are interrupted when the specified time quant is reached, or upon obtaining a guaranteed exact solution. The effectiveness of the algorithm is illustrated by practical examples. It is also shown that for generate a set of finite set of subtasks for GSCCP, it is advisable to use neural networks.
The non-Gaussian rough surface simulation method with desired spatial distribution and height distribution is generally used to analyse the contact characteristics of rough surfaces under different contact conditions....
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The non-Gaussian rough surface simulation method with desired spatial distribution and height distribution is generally used to analyse the contact characteristics of rough surfaces under different contact conditions. Conventional surface simulation methods have disadvantages in terms of their range, accuracy, and stability. In this study, the analytical function method is enhanced to generate non-Gaussian random number matrices. The enhanced method was combined with the spectral representation method and an iterative algorithm to accurately and stably generate rough surfaces characterized by extensive skewness, kurtosis and autocorrelation lengths. The skewness and kurtosis range of the generated rough surface includes skewness and kurtosis of most engineering surfaces, such as worn surfaces and various machined surface and irregular engineering surfaces. A rough surface is easily generated <= 10 s.
In this paper, we investigate one step inversion free iterative algorithm for computing generalised bisymmetric solution to the nonlinear matrix equations (NLME) $ X + {AT}{X{ - q}}A + {BT}{X{ - q}}B = H ({q \ge 2} ) ...
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In this paper, we investigate one step inversion free iterative algorithm for computing generalised bisymmetric solution to the nonlinear matrix equations (NLME) $ X + {A<^>T}{X<^>{ - q}}A + {B<^>T}{X<^>{ - q}}B = H ({q \ge 2} ) $ X+ATX-qA+BTX-qB=H(q >= 2), where $ A,B,H $ A,B,H are given matrices, while $ X $ X is a generalised bisymmetric matrix to be computed. The necessary conditions for the existence of a generalised bisymmetric solution and the convergence of the suggested iterative method are derived. Some lemmas and theorems are provided and proved where the iterative solutions are obtained. Four numerical examples are presented to exhibit the effectiveness of the suggested method and to verify the theoretical findings of this paper.
We propose a simple iterative(SI)algorithm for the maxcut problem through fully using an equivalent continuous *** does not need rounding at all and has advantages that all subproblems have explicit analytic solutions...
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We propose a simple iterative(SI)algorithm for the maxcut problem through fully using an equivalent continuous *** does not need rounding at all and has advantages that all subproblems have explicit analytic solutions,the cut values are monotonically updated and the iteration points converge to a local optima in finite steps via an appropriate subgradient *** experiments on G-set demonstrate the *** particular,the ratios between the best cut values achieved by SI and those by some advanced combinatorial algorithms in[***.,248(2017),365-403]are at least 0.986 and can be further improved to at least 0.997 by a preliminary attempt to break out of local optima.
This paper is devoted to the study of a class of generalized nonexpansive mappings called generalized nearly asymptotically nonexpansive mappings and to show that it properly includes the class of nearly asymptoticall...
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This paper is devoted to the study of a class of generalized nonexpansive mappings called generalized nearly asymptotically nonexpansive mappings and to show that it properly includes the class of nearly asymptotically nonexpansive mappings. We investigate the problem of approximating a common element of the set of solutions of a system of generalized nonlinear variational-like inclusions involving P-eta-accretive mappings and of the set of fixed points of a generalized nearly asymptotically nonexpansive mapping. To this end, we suggest a new iterative algorithm with mixed errors. As an application of the obtained equivalence, we prove the strong convergence and stability of the sequence generated by the proposed iterative algorithm to a common point of the two sets mentioned above.
The total least squares (TLS) algorithm is a superior identification tool for low-order errors-in-variables (EIV) systems, where the estimate can be obtained by solving an eigenvector of the minimum eigenvalue of an a...
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The total least squares (TLS) algorithm is a superior identification tool for low-order errors-in-variables (EIV) systems, where the estimate can be obtained by solving an eigenvector of the minimum eigenvalue of an augmented matrix. However, the TLS algorithm demonstrates inefficiency when applied to high-order EIV systems. This study introduces two innovative TLS algorithms: an iterative TLS algorithm, offering superior performance for low-order EIV models, and a two-step TLS algorithm, designed to effectively handle high-order EIV models. In comparison to the conventional TLS algorithm, these proposed methodologies present noteworthy advantages, including: 1) reduced computational costs, 2) the utilization of an iterative technique to calculate the inverse, and 3) the diversification of EIV identification methods. Simulation bench test examples are selected to show the efficacy of the proposed algorithms and transparent procedure for applications.
In this paper, by the transformation form of the discrete algebraic Riccati equation (DARE), we propose a new inverse-free iterative algorithm to obtain the positive definite solution of the DARE. Furthermore, the mon...
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In this paper, by the transformation form of the discrete algebraic Riccati equation (DARE), we propose a new inverse-free iterative algorithm to obtain the positive definite solution of the DARE. Furthermore, the monotone convergence is proved and convergence rate analysis is presented for the derived algorithm. Compared with some existing algorithms, numerical examples demonstrate the feasibility and effectiveness of our algorithm.
To effectively improve the accuracy of wind power prediction and reduce the load on the power grid, a new nonlinear wind power prediction model based on an improved iterative learning algorithm was investigated. First...
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To effectively improve the accuracy of wind power prediction and reduce the load on the power grid, a new nonlinear wind power prediction model based on an improved iterative learning algorithm was investigated. Firstly, the actual wind conditions are equated to a non-linear model. Using the concept of nonlinear decomposition, the nonlinear model is divided into many linear subdomain models while taking into account the nonlinear impacts of temperature, wind direction, altitude, and speed on the model. Next, using CRITIC weight analysis, the ideal weights are determined. Then, the linear sub-domain model is fitted into the full non-linear wind power prediction model equation by utilizing the least squares method. And the objective function of the iterative algorithm for iterative optimization search is derived from the prediction equations that were previously developed. The final enhanced iterative technique for nonlinear wind power prediction is produced by merging the iterative algorithm with the nonlinear decomposition. Finally, a comparative study of wind power prediction under different prediction models was carried out. The research results showed that the average absolute error of wind power prediction and the root mean square error were 4.5841% and 0.2301%, respectively. In particular, the prediction accuracy improved by 8.28%.
Strong H-tensors play a significant role in identifying the positive definiteness of an even-order real symmetric tensor. In this paper, first, an improved iterative algorithm is proposed to determine whether a given ...
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Strong H-tensors play a significant role in identifying the positive definiteness of an even-order real symmetric tensor. In this paper, first, an improved iterative algorithm is proposed to determine whether a given tensor is a strong H-tensor, and the validity of the iterative algorithm is proved theoretically. Second, the iterative algorithm is employed to identify the positive definiteness of an even-order real symmetric tensor. Finally, numerical examples are presented to illustrate the advantages of the proposed algorithm.
In this study, a new explicit iterative algorithm with a tuning parameter is constructed to solve the Lyapunov matrix equation associated with the discrete-time stochastic systems. Firstly, the boundedness and monoton...
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In this study, a new explicit iterative algorithm with a tuning parameter is constructed to solve the Lyapunov matrix equation associated with the discrete-time stochastic systems. Firstly, the boundedness and monotonicity of the proposed algorithm under zero initial condition are studied when the corresponding stochastic system is asymptotical mean-square stable. In addition, some necessary and sufficient conditions are investigated for the convergence of the proposed algorithm. Furthermore, the optimal tuning parameter is studied to achieve the fastest convergence rate of the algorithm for some special cases, and for the general cases, two searching approaches are given to find the optimal tuning parameter. Finally, three numerical examples are taken to illustrate the correctness of the conclusions in this paper.
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