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Journal articles on the topic 'Quadratic numerical range'

Author: Grafiati

Published: 5 June 2025

Last updated: 15 July 2025

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1

T., H. Rasulov, and B. Dilmurodov E. "QUADRATIC NUMERICAL RANGE AND ITS MAIN PROPERTIES." Physical and mathematical science 3, no. 1 (2022): 21–25. https://doi.org/10.5281/zenodo.6790237.

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In this paper the notion of quadratic numerical range for the operator matrices of order 2 is studied and its main properties are given. Formulas for the quadratic numerical range of the generalized Friedrichs model are described. The estimates for the boundaries of the components of the quadratic numerical range allowed us to determine the location of the eigenvalues of the generalized Friedrichs model.

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2

Li, Chi-Kwong, Yiu-Tung Poon, and Nung-Sing Sze. "Elliptical range theorems for generalized numerical ranges of quadratic operators." Rocky Mountain Journal of Mathematics 41, no. 3 (2011): 813–32. http://dx.doi.org/10.1216/rmj-2011-41-3-813.

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张, 娅. "Numerical Range and Quadratic Numerical Range of Off-Diagonal Infinite Dimensional Hamiltonian Operators." Advances in Applied Mathematics 10, no. 04 (2021): 989–95. http://dx.doi.org/10.12677/aam.2021.104107.

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4

Tretter, Christiane. "The Quadratic Numerical Range of an Analytic Operator Function." Complex Analysis and Operator Theory 4, no. 2 (2009): 449–69. http://dx.doi.org/10.1007/s11785-009-0019-z.

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5

Lancaster, Peter, and Panayiotis Psarrakos. "The Numerical Range of Self-Adjoint Quadratic Matrix Polynomials." SIAM Journal on Matrix Analysis and Applications 23, no. 3 (2002): 615–31. http://dx.doi.org/10.1137/s0895479899364088.

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6

Muhammad, Ahmed, and Marco Marletta. "A numerical investigation of the quadratic numerical range of Hain-Lüst operators." International Journal of Computer Mathematics 90, no. 11 (2013): 2431–51. http://dx.doi.org/10.1080/00207160.2013.780049.

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7

Benabdi, El Hassan, M. Barraa, M. K. Chraibi, and Abderrahim Baghdad. "Maximal numerical range and quadratic elements in a C✻-algebra." Operators and Matrices, no. 4 (2021): 1477–87. http://dx.doi.org/10.7153/oam-2021-15-93.

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8

Langer, H., A. Markus, V. Matsaev, and C. Tretter. "A new concept for block operator matrices:the quadratic numerical range." Linear Algebra and its Applications 330, no. 1-3 (2001): 89–112. http://dx.doi.org/10.1016/s0024-3795(01)00230-0.

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9

Muhammad, Ahmed, and Marco Marletta. "Approximation of the Quadratic Numerical Range of Block Operator Matrices." Integral Equations and Operator Theory 74, no. 2 (2012): 151–62. http://dx.doi.org/10.1007/s00020-012-1971-y.

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10

Clifford, John, Michael Dabkowski та Alan Wiggins. "The Numerical Range of C* ψ Cφ and Cφ C* ψ". Concrete Operators 8, № 1 (2021): 13–23. http://dx.doi.org/10.1515/conop-2020-0108.

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Abstract In this paper we investigate the numerical range of C* bφ m Caφ n and Caφ n C* bφ m on the Hardy space where φ is an inner function fixing the origin and a and b are points in the open unit disc. In the case when |a| = |b| = 1 we characterize the numerical range of these operators by constructing lacunary polynomials of unit norm whose image under the quadratic form incrementally foliate the numerical range. In the case when a and b are small we show numerical range of both operators is equal to the numerical range of the operator restricted to a 3-dimensional subspace.

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11

Tsing, Nam-Kiu, and Frank Uhlig. "Inertia, Numerical Range, and Zeros of Quadratic Forms for Matrix Pencils." SIAM Journal on Matrix Analysis and Applications 12, no. 1 (1991): 146–59. http://dx.doi.org/10.1137/0612011.

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12

Linden, Hansjörg. "The Quadratic Numerical Range and the Location of Zeros of Polynomials." SIAM Journal on Matrix Analysis and Applications 25, no. 1 (2003): 266–84. http://dx.doi.org/10.1137/s0895479802411651.

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13

Li, Yongkang, Tong Wang, Tianyu Huo, and Laisen Nie. "A Study on the Range Equation Modeling for Multichannel Medium-Earth-Orbit SAR-GMTI Systems." Remote Sensing 13, no. 14 (2021): 2734. http://dx.doi.org/10.3390/rs13142734.

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This paper studies the range equation modeling of a ground moving target for multichannel medium-Earth-orbit (MEO) synthetic aperture radar (SAR) ground moving target indication (GMTI), an issue which is challenging to tackle due to the non-linear motion of the radar platform and the Earth rotation. In the paper, the coordinates of the multichannel MEO SAR and the target, as well as the target’s range equation with respect to each channel, are developed. Moreover, an expression of concise form is derived for the target’s quadratic-approximated range equation, which will benefit the design of G

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14

Lancaster, Peter, Alexander S. Markus, and Panayiotis Psarrakos. "Repeated eigenvectors and the numerical range of self-adjoint quadratic operator polynomials." Integral Equations and Operator Theory 44, no. 2 (2002): 243–53. http://dx.doi.org/10.1007/bf01217534.

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15

Liu, Jie, Junjie Huang, and Alatancang Chen. "Spectral inclusion by the quadratic numerical range of 2 x 2 operator matrices with unbounded entries." Filomat 34, no. 4 (2020): 1283–93. http://dx.doi.org/10.2298/fil2004283l.

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This paper deals with the spectral inclusion properties of 2 x 2 operator matrices with unbounded entries in Hilbert space. The conditions for spectral inclusion by the quadratic numerical range are described. In addition, some examples are given to illustrate the main results.

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16

Liu, Jie, Junjie Huang, and Alatancang Chen. "Spectral inclusion by the quadratic numerical range of 2 x 2 operator matrices with unbounded entries." Filomat 34, no. 4 (2020): 1283–93. http://dx.doi.org/10.2298/fil2004283l.

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This paper deals with the spectral inclusion properties of 2 x 2 operator matrices with unbounded entries in Hilbert space. The conditions for spectral inclusion by the quadratic numerical range are described. In addition, some examples are given to illustrate the main results.

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17

Frommer, Andreas, Brigit Jacob, Kartsen Kahl, Christian Wyss, and Ian Zwaan. "Krylov type methods for linear systems exploiting properties of the quadratic numerical range." ETNA - Electronic Transactions on Numerical Analysis 53 (2020): 541–61. http://dx.doi.org/10.1553/etna_vol53s541.

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18

Jiao, Hongwei, and Yongqiang Chen. "A Global Optimization Algorithm for Generalized Quadratic Programming." Journal of Applied Mathematics 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/215312.

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We present a global optimization algorithm for solving generalized quadratic programming (GQP), that is, nonconvex quadratic programming with nonconvex quadratic constraints. By utilizing a new linearizing technique, the initial nonconvex programming problem (GQP) is reduced to a sequence of relaxation linear programming problems. To improve the computational efficiency of the algorithm, a range reduction technique is employed in the branch and bound procedure. The proposed algorithm is convergent to the global minimum of the (GQP) by means of the subsequent solutions of a series of relaxation

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19

Huang, J., J. Liu, and A. Chen. "Symmetry of the Quadratic Numerical Range and Spectral Inclusion Properties of Hamiltonian Operator Matrices." Mathematical Notes 103, no. 5-6 (2018): 1007–13. http://dx.doi.org/10.1134/s0001434618050371.

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20

Khadkhuu, Lkhamjav, and Dashdondog Tsedenbayar. "note on self-commutators of Volterra operator and its square." Journal of Applied Science and Engineering A 3, no. 1 (2022): 11–16. http://dx.doi.org/10.5564/jasea.v3i1.2455.

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Let V be the classical Volterra operator on L2(0, 1). The quadratic forms and their applications are used in many branches of mathematics. In this area of mathematics have studied many properties for concrete operator such as the numerical range. In recent year, the concept of Volterra operator has attached the serious attention of many researchers. In this paper, we compute the operator norm of self-commutators of V and its square. We also study the length of arc and the area of numerical range of V.

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21

Exl, Lukas, Claas Abert, Norbert J. Mauser, Thomas Schrefl, Hans Peter Stimming, and Dieter Suess. "FFT-based Kronecker product approximation to micromagnetic long-range interactions." Mathematical Models and Methods in Applied Sciences 24, no. 09 (2014): 1877–901. http://dx.doi.org/10.1142/s0218202514500109.

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We derive a Kronecker product approximation for the micromagnetic long-range interactions in a collocation framework by means of separable sinc quadrature. Evaluation of this operator for structured tensors (Canonical format, Tucker format, Tensor Trains) scales below linear in the volume size. Based on efficient usage of FFT for structured tensors, we are able to accelerate computations to quasi-linear complexity in the number of collocation points used in one dimension. Quadratic convergence of the underlying collocation scheme as well as exponential convergence in the separation rank of the

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22

Wang, Yuying, Xuefeng Zhang, Driss Boutat та Peng Shi. "Quadratic Admissibility for a Class of LTI Uncertain Singular Fractional-Order Systems with 0<α<2". Fractal and Fractional 7, № 1 (2022): 1. http://dx.doi.org/10.3390/fractalfract7010001.

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This paper provides a unified framework for the admissibility of a class of singular fractional-order systems with a given fractional order in the interval (0,2). These necessary and sufficient conditions are derived in terms of linear matrix inequalities (LMIs). The considered fractional orders range from 0 to 2 without separating the ranges into (0,1) and [1,2) to discuss the admissibility. Moreover, the uncertain system with the fractional order in the interval (0,2) is norm-bounded. The quadratic admissibility and general quadratic stability of the system are analyzed, and the equivalence

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23

Ramesh, Sai Sudha, Kian-Meng Lim, and Boo Cheong Khoo. "Comparison of Constant and Discontinuous Quadratic Boundary Elements for Exterior Axisymmetric Acoustic-Wave Propagation Problems." Journal of Computational Acoustics 23, no. 04 (2015): 1540003. http://dx.doi.org/10.1142/s0218396x15400032.

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The present study involves numerical assessment of two types of boundary elements, namely constant and discontinuous quadratic elements based on a hypersingular Burton and Miller boundary integral formulation to tackle spurious frequencies manifesting in exterior problems. Convergence trends of the two types of boundary element with/without the inclusion of hypersingular formulation were studied for various combinations of boundary conditions and over a wide range of frequencies. The results indicate that discontinuous quadratic elements and constant elements give comparable results, with the

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24

Fabien, B. C., R. W. Longman, and F. Freudenstein. "The Design of High-Speed Dwell-Rise-Dwell Cams Using Linear Quadratic Optimal Control Theory." Journal of Mechanical Design 116, no. 3 (1994): 867–74. http://dx.doi.org/10.1115/1.2919462.

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This paper uses linear quadratic optimal control theory to design high-speed Dwell-Rise-Dwell (D-R-D) cams. Three approaches to D-R-D cam design are compared. In the first approach the cam is designed to be optimal at a fixed operating speed, i.e., a tuned cam design is obtained. In the second approach the cam profile is determined by minimizing a sum of quadratic cost functions over a range of discrete speeds, thus producing a cam-follower system which is optimal over a range of speeds. The third technique uses trajectory sensitivity minimization to design a cam which is insensitive to speed

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25

Olshanskiy, Vasil, Stanislav Olshanskiy, and Maksym Slipchenko. "Non-stationary oscillations of an instantly loaded oscillator under conditions of nonlinear resistance." Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines, no. 1 (December 31, 2021): 48–54. http://dx.doi.org/10.20998/2078-9130.2021.1.232307.

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The motion of an oscillator instantaneously loaded with a constant force under conditions of nonlinear external resistance, the components of which are quadratic viscous resistance, dry and positional friction, are considered. Using the first integral of the equation of motion and the Lambert function, compact formulas for calculating the ranges of oscillations are derived. In order to simplify the search for the values of the Lambert function, asymptotic formulas are given that, with an error of less than one percent, express this special function in terms of elementary functions. It is shown

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26

Carini, A., and O. De Donato. "Numerical analysis of large deformation rigid-plastic problems in dynamic range by quadratic extremum principles." Computer Methods in Applied Mechanics and Engineering 111, no. 1-2 (1994): 61–84. http://dx.doi.org/10.1016/0045-7825(94)90040-x.

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27

Hou, Zhenyu, Zehua Zhang, Pin Li, Zhuo Yun, Feng He, and Zhen Dong. "Range-Dependent Variance Correction Method for High-Resolution and Wide-Swath Spaceborne Synthetic Aperture Radar Imaging Based on Block Processing in Range Dimension." Remote Sensing 17, no. 1 (2024): 50. https://doi.org/10.3390/rs17010050.

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With increasing demands for SAR image applications, spaceborne SAR systems are evolving towards higher resolution and wider swath capabilities. However, these advancements lead to more pronounced range-dependent variance effects. Previous research has primarily focused on the impact of range-dependent variance on range cell migration and the quadratic phase of range frequency, while often neglecting the effects of the cubic phase of range frequency. Although some block processing methods have addressed the range-dependent variant cubic phase of range frequency, they lack detailed impact analys

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28

Han, Congying, Mingqiang Li, Tong Zhao, and Tiande Guo. "An Accelerated Proximal Gradient Algorithm for Singly Linearly Constrained Quadratic Programs with Box Constraints." Scientific World Journal 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/246596.

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Recently, the existed proximal gradient algorithms had been used to solve non-smooth convex optimization problems. As a special nonsmooth convex problem, the singly linearly constrained quadratic programs with box constraints appear in a wide range of applications. Hence, we propose an accelerated proximal gradient algorithm for singly linearly constrained quadratic programs with box constraints. At each iteration, the subproblem whose Hessian matrix is diagonal and positive definite is an easy model which can be solved efficiently via searching a root of a piecewise linear function. It is pro

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29

Hussein, Ihsan Y., and Luma F. Ali. "Mixed Convection in a Square Cavity Filled with Porous Medium with Bottom Wall Periodic Boundary Condition." Journal of Engineering 20, no. 04 (2023): 99–119. http://dx.doi.org/10.31026/j.eng.2014.04.07.

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Transient mixed convection heat transfer in a confined porous medium heated at periodic sinusoidal heat flux is investigated numerically in the present paper. The Poisson-type pressure equation, resulted from the substituting of the momentum Darcy equation in the continuity equation, was discretized by using finite volume technique. The energy equation was solved by a fully implicit control volume-based finite difference formulation for the diffusion terms with the use of the quadratic upstream interpolation for convective kinetics scheme to discretize the convective terms and the temperature

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30

Wang, Rongrong, Bingnan Wang, Yachao Wang, Wei Li, Zhongbin Wang, and Maosheng Xiang. "Time-Varying Vibration Compensation Based on Segmented Interference for Triangular FMCW LiDAR Signals." Remote Sensing 13, no. 19 (2021): 3803. http://dx.doi.org/10.3390/rs13193803.

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Frequency modulation continuous wave (FMCW) light detection and ranging (LiDAR) 3D imaging system may suffer from time-varying vibrations which will affect the accuracy of ranging and imaging of a target. The system uses only a single-period FMCW LiDAR signal to measure the range of each spot; however, traditional methods may not work well to compensate for the time-varying vibrations in a single period because they generally assume the vibration velocity is constant. To solve this problem, we propose a time-varying vibration compensation method based on segmented interference. We first derive

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31

Kaveri, Sinha Mahapatra. "Low Earth Orbiting (LEO) Satellite and Orbital Decay." International Journal of Engineering and Advanced Technology (IJEAT) 12, no. 1 (2022): 88–91. https://doi.org/10.35940/ijeat.A3849.1012122.

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<strong>Abstract:</strong> In this article we present a simple but elegant numerical calculation to study the motion of a low earth orbiting (LEO) satellite in gravitational potential and under the influence of quadratic drag force. We solve a set of coupled differential equations to calculate the instantaneous position and velocity of the satellite and calculate the change in radial distance for different aerodynamic coefficients and altitude. We validate our numerical results with theoretical result in the high altitude where the density of air and consequently the drag force is minimum. How

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32

Wang, Tingjing, Ying Zhang, Hua Zhao, and Yanxin Zhang. "Multiband Radar Signal Coherent Processing Algorithm for Motion Target." International Journal of Antennas and Propagation 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/4060789.

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In real application, most aerial targets are movable. In this paper, an effective multiple subbands coherent processing method is proposed for moving target. Firstly, an echoed signal model of motion target based on geometrical theory of diffraction is established and the influence of velocity on range profile of the target is analyzed. Secondly, a method based on minimum entropy principle is used to compensate velocity. Then, incoherent factors including a quadratic phase term, a linear phase factor, a fixed factor, and an amplitude difference term are analyzed. Subsequently, efficient method

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33

Krupnik, Naum. "On the lengths of Jordan chains for eigenvalues on the boundary of numerical range of quadratic operator polynomial." Linear Algebra and its Applications 385 (July 2004): 131–47. http://dx.doi.org/10.1016/j.laa.2003.07.002.

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34

Trofimov, V. A., and O. V. Matusevich. "NUMERICAL METHOD FOR 2D SOLITON SOLUTION AT SHG IN MEDIA WITH TIME‐DEPENDENT COMBINED NONLINEARITY." Mathematical Modelling and Analysis 13, no. 1 (2008): 123–33. http://dx.doi.org/10.3846/1392-6292.2008.13.123-133.

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The paper describes the iteration method for finding the eigenfunctions and eigenvalues of the system of two nonlinear Schrödinger equations, which describes the process of second harmonic generation by femtosecond pulse in media with the quadratic and cubic nonlinear response. Coefficients, which characterize the nonlinearities, depend on one of the coordinate. The discussed method allows to find soliton solutions of new form corresponding to the first and second eigenvalues for the wide range of the nonlinear coefficients values. For determination of the eigenfunctions of the third and highe

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35

Wu, Kun, Haiyan Hu, and Lifeng Wang. "Optimization of a type of elastic metamaterial for broadband wave suppression." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 477, no. 2251 (2021): 20210337. http://dx.doi.org/10.1098/rspa.2021.0337.

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The optimal design is studied for a type of one-dimensional dissipative metamaterial to achieve broadband wave attenuation at low-frequency ranges. The complex dispersion analysis is made on a super-cell consisting of multiple mass-in-mass unit cells. An optimization algorithm based on the sequential quadratic programming method is used to design the wave suppression of target frequencies by coupling multiple separate narrow bandgaps into a broad bandgap. A new objective function is proposed in the optimization process for a continuous bandgap. Then, the continuous frequency range with low-wav

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36

Qiao, Qing Qing, and Wan Chun Chen. "Dynamic Inversion Guidance Law for a Hypersonic Vehicle." Advanced Materials Research 383-390 (November 2011): 4451–56. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.4451.

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An adapting dynamic inversion guidance law developed by using integral of time multiply by absolute error (ITAE) performance index for a hypersonic vehicle was studied. As a nominal trajectory, Maximum-Range glide trajectory was obtained by using collocation and successive quadratic programming. Dynamic inversion technique was employed to produce a guidance law which contains two PID controllers. To find optimal guidance parameters, ITAE criteria were used to tune the PID parameters. The numerical result showed that the guidance law was simple and efficient for a hypersonic vehicle flies along

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37

Hunt, G. W., M. K. Wadee, and N. Shiacolas. "Localized Elasticae for the Strut on the Linear Foundation." Journal of Applied Mechanics 60, no. 4 (1993): 1033–38. http://dx.doi.org/10.1115/1.2900971.

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Localized solutions, for the classical problem of the nonlinear strut (elastica) on the linear elastic foundation, are predicted from double-scale analysis, and confirmed from nonlinear volume-preserving Runge-Kutta runs. The dynamical phase-space analogy introduces a spatial Lagrangian function, valid over the initial post-buckling range, with kinetic and potential energy components. The indefinite quadratic form of the spatial kinetic energy admits unbounded solutions, corresponding to escape from a potential well. Numerical experimentation demonstrates that there is a fractal edge to the es

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38

Yazici, Hakan, and Mert Sever. "Active control of a non-linear landing gear system having oleo pneumatic shock absorber using robust linear quadratic regulator approach." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 232, no. 13 (2017): 2397–411. http://dx.doi.org/10.1177/0954410017713773.

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This paper deals with the active control of a non-linear active landing gear system equipped with oleo pneumatic shock absorber. Runway induced vibration can cause reduction of pilot’s capability of control the aircraft and results the safety problem before take-off and after landing. Moreover, passenger–crew comfort is adversely affected by vertical vibrations of the fuselage. The active landing gears equipped with oleo pneumatic shock absorber are highly non-linear systems. In this study, uncertain polytopic state space representation is developed by modelling the pneumatic shock absorber dy

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39

Ashar, Nurcahya Yulian, and Hafidh Khoerul Fata. "Bifurcation and Dynamics in a 3D System with Quadratic Coupling." International Journal of Research and Review 12, no. 6 (2025): 669–74. https://doi.org/10.52403/ijrr.20250676.

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This research explores the behavior of a three-dimensional autonomous nonlinear system featuring both quadratic and bilinear interaction terms. The system is developed as an extension of the SE8 model proposed by Molaie et al., with modifications that introduce additional nonlinearities through the inclusion of and components in the third equation. Although the system has a single equilibrium point and a relatively simple structure, it displays a wide range of complex dynamical phenomena, such as bifurcations, multistability, and chaotic attractors. To analyze these dynamics, equilibrium point

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40

Mahapatra, Kaveri Sinha. "Low Earth Orbiting (LEO) Satellite and Orbital Decay." International Journal of Engineering and Advanced Technology 12, no. 1 (2022): 88–91. http://dx.doi.org/10.35940/ijeat.a3849.1012122.

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In this article we present a simple but elegant numerical calculation to study the motion of a low earth orbiting (LEO) satellite in gravitational potential and under the influence of quadratic drag force. We solve a set of coupled differential equations to calculate the instantaneous position and velocity of the satellite and calculate the change in radial distance for different aerodynamic coefficients and altitude. We validate our numerical results with theoretical result in the high altitude where the density of air and consequently the drag force is minimum. However the LEO orbits placed

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41

Zhang, Yiqun, Guisheng Liao, Jingwei Xu, and Lan Lan. "Mainlobe Deceptive Jammer Suppression Based on Quadratic Phase Coding in FDA-MIMO Radar." Remote Sensing 14, no. 22 (2022): 5831. http://dx.doi.org/10.3390/rs14225831.

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In this paper, the problem of mainlobe deceptive jammer suppression is solved with the frequency diversity array-multiple-input multiple-output (FDA-MIMO) radar system. At the modeling stage, based on the FDA-MIMO radar, a quadratic phase code (QPC) is applied along the slow time dimension in the transmit array. In the receiver, after decoding and principal range compensation, the true and false targets that are generated in an identical angle, can be discriminated in the joint transmit-receive-Doppler frequency domain. Particularly, the false targets are equivalently moved from the mainlobe t

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42

Arbic, Brian K., and Robert B. Scott. "On Quadratic Bottom Drag, Geostrophic Turbulence, and Oceanic Mesoscale Eddies." Journal of Physical Oceanography 38, no. 1 (2008): 84–103. http://dx.doi.org/10.1175/2007jpo3653.1.

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Abstract Many investigators have idealized the oceanic mesoscale eddy field with numerical simulations of geostrophic turbulence forced by a horizontally homogeneous, baroclinically unstable mean flow. To date such studies have employed linear bottom Ekman friction (hereinafter, linear drag). This paper presents simulations of two-layer baroclinically unstable geostrophic turbulence damped by quadratic bottom drag, which is generally thought to be more realistic. The goals of the paper are 1) to describe the behavior of quadratically damped turbulence as drag strength changes, using previously

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43

Sedlář, Milan, Tomáš Krátký, and Jiří Langer. "Numerical and Experimental Investigation of Three-Dimensional Flow in Combined Protective Canister Filters." Fluids 7, no. 5 (2022): 171. http://dx.doi.org/10.3390/fluids7050171.

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This work deals with the numerical and experimental investigation of flow in the protective filters which combine fibrous pleats and the absorbent cartridge. The flow through the complete 3D geometry of all parts of the filters, including complex geometry of the pleats, is numerically modeled using high-quality computational grids. The sorbent filling, textile dividers as well as the material of filtration pleats are modeled as the porous media with the coefficients of the quadratic Forchheimer equation derived from the experiments in the laboratory located at the SIGMA Research and Developmen

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44

Kushnir, R. M., and O. I. Soliar. "Friction interaction of elastic bodies with unspecified contact zones." Physicochemical Mechanics of Materials 61, no. 2 (2025): 64–74. https://doi.org/10.15407/pcmm2025.02.064.

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An efficient method for solving the frictional contact problem of two interacting elastic bodies is proposed. The approach is based on a numerical-analytical algorithm using Signorini’s method of integral equations-inequalities, which is subsequently reduced to a quadratic programming problem. Using the developed algorithm, the contact pressure was determined for various levels of mutual penetration for a wide range of friction coefficients and Poisson’s ratios. The accuracy of the obtained numerical results was investigated, It was demonstrated that, for the case of a smooth punch, the comput

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45

GOMES, A. R., B. BASEIA, and G. C. MARQUES. "MUTUAL TRANSFER OF SQUEEZING EFFECT IN COUPLED TWO-PHOTON LASERS." Modern Physics Letters B 09, no. 16 (1995): 999–1015. http://dx.doi.org/10.1142/s0217984995000978.

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We investigate the mutual influence of two interacting 2-photon lasers, each subsystem being modelled as a quadratic oscillator in terms of the ladder operators âi, [Formula: see text] owing to the generation and transfer of squeezing effect. We find an exact solution for this coupled system which allows us to obtain the variances in the conjugate operators ẑi, [Formula: see text]. The results are exhibited in several plots showing the influence of the involved parameters. The second oscillator exhibits squeezing even if its nonlinear term is absent, due to the transference of the effect origi

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Tami, Y., K. Sebaa, M. Lahdeb, O. Usta, and H. Nouri. "Extended mixed integer quadratic programming for simultaneous distributed generation location and network reconfiguration." Electrical Engineering & Electromechanics, no. 2 (March 5, 2023): 93–100. http://dx.doi.org/10.20998/2074-272x.2023.2.14.

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Introduction. To minimise power loss, maintain the voltage within the acceptable range, and improve power quality in power distribution networks, reconfiguration and optimal distributed generation placement are presented. Power flow analysis and advanced optimization techniques that can handle significant combinatorial problems must be used in distribution network reconfiguration investigations. The optimization approach to be used depends on the size of the distribution network. Our methodology simultaneously addresses two nonlinear discrete optimization problems to construct an intelligent a

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Fauzi, Mohd Azrizal, Mohd Fadzil Arshad, Noorsuhada Md Nor, and Ezliana Ghazali. "Optimising Controlled Low-Strength Material: Unravelling the Impact of Key Mixture Parameters." Jurnal Kejuruteraan 37, no. 3 (2025): 1085–97. https://doi.org/10.17576/jkukm-2025-37(3)-02.

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Controlled Low-Strength Material (CLSM) is increasingly utilised in construction for its advantageous properties such as self-compaction and cost-effectiveness. However, well-established models are lacking in predicting its fresh and hardened properties, particularly when incorporating Waste Paper Sludge Ash (WPSA) as a supplementary cementitious material (SCM). Statistical models have been carried out to model the influence of key mixture parameters (water-to-cementitious material ratio, WPSA percentage, and total cementitious material) on fresh and hardened properties affecting the performan

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Nguyen, Son L., Dung T. Nguyen, and George Yin. "A stochastic maximum principle for switching diffusions using conditional mean-fields with applications to control problems." ESAIM: Control, Optimisation and Calculus of Variations 26 (2020): 69. http://dx.doi.org/10.1051/cocv/2019055.

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This paper obtains a maximum principle for switching diffusions with mean-field interactions. The motivation stems from a wide range of applications for networked control systems in which large-scale systems are encountered and mean-field interactions are involved. Because of the complexity due to the switching, little has been done for the associate control problems with mean-field interactions. The main ingredient of this work is the use of conditional mean-fields, which is distinct from the existing literature. Using the maximum principle, optimal controls of linear quadratic Gaussian contr

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Panagiotou, Constantinos F., Fotos S. Stylianou, Elias Gravanis, Evangelos Akylas, and Constantine Michailides. "An Explicit Algebraic Closure for Passive Scalar-Flux: Applications in Channel Flows at a Wide Range of Reynolds Numbers." Journal of Marine Science and Engineering 8, no. 11 (2020): 916. http://dx.doi.org/10.3390/jmse8110916.

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In this paper, we propose an algebraic model for turbulent scalar-flux vector that stems from tensor representation theory. The resulting closure contains direct dependence on mean velocity gradients and quadratic products of the Reynolds stress tensor. Model coefficients are determined from Direct Numerical Simulations (DNS) data of homogeneous shear flows subjected to arbitrary mean scalar gradient orientations, while a correction function was applied at one model coefficient based on a turbulent channel flow case. Model performance is evaluated in Poiseuille and Couette flows at several Rey

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Y., Tami, Sebaa K., Lahdeb M., Usta O., and Nouri H. "Extended mixed integer quadratic programming for simultaneous distributed generation location and network reconfiguration." Electrical Engineering & Electromechanics, no. 2 (March 5, 2023): 93–100. https://doi.org/10.20998/2074-272X.2023.2.14.

Full text

Abstract:

<strong><em>Introduction.</em></strong> <em>To minimise power loss, maintain the voltage within the acceptable range, and improve power quality in power distribution networks, reconfiguration and optimal distributed generation placement are presented. Power flow analysis and advanced optimization techniques that can handle significant combinatorial problems must be used in distribution network reconfiguration investigations. The optimization approach to be used depends on the size of the distribution network. Our <strong>methodology</strong> simultaneously addresses two nonlinea

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