scholarly journals Analyticity of Semigroups Generated by Singular Differential Matrix Operators

2010 ◽  
Vol 01 (04) ◽  
pp. 283-287
Author(s):  
Ould Ahmed Mahmoud Sid Ahmed ◽  
Adel Saddi
Keyword(s):  
Matrix Operators ◽  
Differential Matrix

scholarly journals Generalized Green's functions for higher order boundary value matrix differential systems

1992 ◽  
Vol 15 (3) ◽  
pp. 523-535 ◽  
Author(s):  
R. J. Villanueva ◽  
L. Jodar
Keyword(s):  
Boundary Value ◽  
Existence Condition ◽  
Higher Order ◽  
Closed Form Expression ◽  
Problem Dimension ◽  
Green’S Matrix ◽  
Matrix Differential ◽  
Matrix Problems ◽  
Differential Matrix ◽  
Well Posed

In this paper, a Green's matrix function for higher order two point boundary value differential matrix problems is constructed. By using the concept of rectangular co-solution of certain algebraic matrix equation associated to the problem, an existence condition as well as an explicit closed form expression for the solution of possibly not well-posed boundary value problems is given avoiding the increase of the problem dimension.

The Essential Spectrum of Some Matrix Operators

1994 ◽  
Vol 167 (1) ◽  
pp. 5-20 ◽  
Author(s):  
F. V. Atkinson ◽  
H. Langer ◽  
R. Mennicken ◽  
A. A. Shkalikov
Keyword(s):  
Essential Spectrum ◽  
Matrix Operators

Double-Clutch Power Shift Quality Optimization Based on Optimal Control Theory

2021 ◽  
Vol 37 (4) ◽  
pp. 677-689
Author(s):  
Guang Xia ◽  
Yueqiang Wang ◽  
Xiwen Tang ◽  
Linfeng Zhao ◽  
Jinfang Hu
Keyword(s):  
Optimal Control ◽  
Control Theory ◽  
Control Strategy ◽  
Optimal Control Theory ◽  
Multiple Target ◽  
Shift Quality ◽  
Shift Control ◽  
Power Shift ◽  
Multiparameter Optimization ◽  
Differential Matrix

Highlights A power shift control strategy based on torque and speed transition, which aims to deliver multiple target and multiparameter optimization of power shift control, is proposed in this study. It can effectively solve the shift power cycle. Based on minimum optimal control theory, the optimal control of shift quality during power shifting optimizes clutch terminal oil pressure, which is determined by solving the Rebecca differential matrix equation and shift characteristics based on various stages. By aiming at the multiple target and multiparameter optimization problem of the clutch control in the power shift process, the minimum optimal control principle is applied to the shift quality optimization of the power shift. Based on the minimum optimal control theory, the optimal solution of the terminal oil pressure of the clutch is determined by solving the Rebecca differential matrix equation to improve the shift quality of the power shift process. Abstract . The dual clutch of the combined transmission of a tractor with large horsepower uses a dynamic shifting process, in which only one clutch undergoes slipping friction during the shift. A power shift control strategy based on torque and speed transition, which aims to deliver multiple target and multiparameter optimization of power shift control, is proposed in this study. Based on minimum optimal control theory, the optimal control of shift quality during power shifting optimizes clutch terminal oil pressure, which is determined by solving the Rebecca differential matrix equation and shift characteristics based on various stages. In addition, the power shift simulation model of the double clutch is established. Simulation results show that the power shift control strategy based on single slip friction can effectively avoid power flow cycle, uninterruptible tractor power shift, and adaptive resistance change. The minimum optimization theory can effectively reduce the output torque fluctuation in the dynamic shift process, reduce friction work, and improve the shift impact. Keywords: Double clutch, Heavy-horsepower tractor, Minimum theory, Power shift.

Fast and high-precision calculation of earth return mutual impedance between conductors over a multilayered soil

2018 ◽  
Vol 37 (3) ◽  
pp. 1214-1227 ◽  
Author(s):  
Junjie Ma
Keyword(s):  
Quadrature Rule ◽  
Content Type ◽  
Mutual Impedance ◽  
Numerical Tests ◽  
Sommerfeld Integral ◽  
The Earth ◽  
Finite Integral ◽  
Infinite Integral ◽  
Improper Integrals ◽  
Differential Matrix

Purpose Solutions for the earth return mutual impedance play an important role in analyzing couplings of multi-conductor systems. Generally, the mutual impedance is approximated by Pollaczek integrals. The purpose of this paper is devising fast algorithms for calculation of this kind of improper integrals and its applications. Design/methodology/approach According to singular points, the Pollaczek integral is divided into two parts: the finite integral and the infinite integral. The finite part is computed by combining an efficient Levin method, which is implemented with a Chebyshev differential matrix. By transforming the integration path, the tail integral is calculated with help of a transformed Clenshaw–Curtis quadrature rule. Findings Numerical tests show that this new method is robust to high oscillation and nearly singularities. Thus, it is suitable for evaluating Pollaczek integrals. Furthermore, compared with existing method, the presented algorithm gives high-order approaches for the earth return mutual impedance between conductors over a multilayered soil with wide ranges of parameters. Originality/value An efficient truncation strategy is proposed to accelerate numerical calculation of Pollaczek integral. Compared with existing algorithms, this method is easier to be applied to computation of similar improper integrals, such as Sommerfeld integral.

scholarly journals Gyroaveraging operations using adaptive matrix operators

2018 ◽  
Vol 25 (5) ◽  
pp. 052304 ◽  
Author(s):  
Julien Dominski ◽  
Seung-Hoe Ku ◽  
Choong-Seock Chang
Keyword(s):  
Matrix Operators
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