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1 – 10 of 41U.G. Eziefula, D.O. Onwuka and O.M. Ibearugbulem
The purpose of this paper is to analyze the inelastic buckling of a rectangular thin flat isotropic plate subjected to uniform uniaxial in-plane compression using a work…
Abstract
Purpose
The purpose of this paper is to analyze the inelastic buckling of a rectangular thin flat isotropic plate subjected to uniform uniaxial in-plane compression using a work principle, a deformation plasticity theory and Taylor–Maclaurin series formulation.
Design/methodology/approach
The non-loaded longitudinal edges of the rectangular plate are clamped, whereas the loaded edges are simply supported (CSCS). Total work error function is applied to Stowell’s plasticity theory in the derivation of the inelastic buckling equation. Mathematical formulation of the Taylor–Maclaurin series deflection function satisfied the boundary conditions of the CSCS rectangular plate. The critical inelastic load of the plate is then derived by applying variational principles.
Findings
Values of the plate buckling coefficient are calculated using various values of moduli ratio for aspect ratios ranging from 0.1 to 1.0, in intervals of 0.1. The accuracy of the proposed technique is validated by comparing the results obtained in the present study with solutions from a previous investigation. The percentage differences in the values of the buckling coefficient ranged from −0.122 to −4.685 per cent.
Originality/value
The results indicate that the work principle approach can be used as an alternative approximate method for analyzing inelastic buckling of rectangular thin flat isotropic plates under uniform in-plane compressive loads.
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Computer algebra or symbolic manipulation is nothing else than performing analytical calculations with the help of a computer. This offers the advantage that lengthy and…
Abstract
Computer algebra or symbolic manipulation is nothing else than performing analytical calculations with the help of a computer. This offers the advantage that lengthy and complicated calculations can be carried out without errors in a very short time. Computer algebra techniques have also been applied to solve electrical networks. This offers particular advantages for hybrid circuit design, as will be outlined extensively in this paper.
The numerical solution of a two‐dimensional thermal problem governed by a third‐order partial differential equation derived from a non‐Fourier heat flux model which may account…
Abstract
The numerical solution of a two‐dimensional thermal problem governed by a third‐order partial differential equation derived from a non‐Fourier heat flux model which may account for thermal waves and/or microscopic effects is considered. A dual‐reciprocity boundary element method is proposed for solving the problem in the Laplace transformation domain. The solution in the physical domain is recovered by a numerical inverse Laplace transformation technique.
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This paper aims to propose a reference model based simple strategy for the design of proportional-integral-derivative (PID) controller using frequency response matching for…
Abstract
Purpose
This paper aims to propose a reference model based simple strategy for the design of proportional-integral-derivative (PID) controller using frequency response matching for high-order stable, integrating and unstable processes that may have time-delay and non-minimum phase zero.
Design/methodology/approach
The reference sensitivity model is designed fulfilling stability conditions of the control system responses such as set-point response, load-disturbance response and noise response along with transient response criteria. The analytical controller thus designed is approximated to a PID controller using a simple formula based on a model-matching technique at low frequency.
Findings
PID controllers are designed for examples with varied dynamics taken from the literature, and the performances of the designed control systems are compared with some methods prevalent in the literature to show the efficacy of the proposed work. Overall, the method gives satisfactory set-point, as well as load-disturbance responses and controller-outputs in all the cases considered.
Originality/value
The method is applicable to high-order processes of various monotonic or oscillating dynamics without requiring process reduction. The PID controller designed considering a reference model with suitable criteria ensuring stability and a modified model matching technique, which provides a stable control system for all these high-order processes.
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The purpose of this paper is to investigate the circuit analysis differential equations, which play an important role in the field of electrical and electronic engineering, and it…
Abstract
Purpose
The purpose of this paper is to investigate the circuit analysis differential equations, which play an important role in the field of electrical and electronic engineering, and it was necessary to propose a very simple and direct method to obtain approximate solutions for the linear or non-linear differential equations, which should be simple for engineers to understand.
Design/methodology/approach
This paper introduces a simple novel Maclaurin series method (MSM) to propose an approximate novel solution in the area of circuit analysis for linear and non-linear differential equations. These equations describe the alternating current circuit of the resistor–capacitor, which evaluates the effect of non-linear current resistance. Linear and non-linear differential equations are evaluated as a computational analysis to assist the research, which reveals that the MSM is incredibly simple and effective.
Findings
Simulation findings indicate that the achieved proposed solution using the novel suggested approach is identical to the exact solutions mentioned in the literature. As the Maclaurin series is available to all non-mathematicians, this paper reflects mostly on theoretical implementations of the numerous circuit problems that occur in the field of electrical engineering.
Originality/value
A very simple and efficient method has been proposed in this paper, which is very easy to understand for even non-mathematicians such as engineers. The paper introduced a method of the Maclaurin series to solve non-linear differential equations resulting from the study of the circuits. The MSM mentioned here will be a useful tool in areas of physical and engineering anywhere the problem of the circuits is studied.
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Daniel A. Wren, Regina A. Greenwood, Julia Teahen and Arthur G. Bedeian
This paper aims to highlight myriad accomplishments of C. Bertrand Thompson, who is perhaps most well known as a scientific-management bibliographer and a Taylor disciple, in the…
Abstract
Purpose
This paper aims to highlight myriad accomplishments of C. Bertrand Thompson, who is perhaps most well known as a scientific-management bibliographer and a Taylor disciple, in the belief that his contributions as a pioneer management theorist and consultant in Europe deserve to be more widely known and more deeply appreciated.
Design/methodology/approach
Archival, primary and secondary sources were used in the research.
Findings
Thompson was among the first to bring management consulting to Europe. He understood the importance of adapting scientific-management principles to meet the diverse needs of each client for whom he consulted. Thompson’s strong belief and value system remained constant throughout his life.
Practical implications
Understanding the needs of customers or clients and adapting systems to meet those needs is essential in achieving success as a consultant.
Originality/value
By drawing on rarely accessed published and unpublished materials, this paper discusses Thompson’s many contributions to management thought and practice, most of which previously have not been highlighted in the referent literature.
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M. Inc and Y. Cherruault
We use the Adomian decomposition method to study a non‐linear diffusion‐convection problem (NDCP). The decomposition method has been applied recently to a wide class of non‐linear…
Abstract
We use the Adomian decomposition method to study a non‐linear diffusion‐convection problem (NDCP). The decomposition method has been applied recently to a wide class of non‐linear stochastic and deterministic operator equations involving algebraic, differential, integro‐differential and partial differential equations and systems. The method provides a solution without linearization, perturbation, or unjustified assumptions. An analytic solution of NDCP in the form of a series with easily computable components using the decomposition method will be determined. The non‐homogeneous equation is effectively solved by employing the phenomena of the self‐cancelling ‘noise terms’ whose sum vanishes in the limit. Comparing the methodology with some known techniques shows that the present approach is highly accurate.
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Vedat Suat Erturk and Shaher Momani
The purpose of this paper is to solve both the prey and predator problem and the problem of the spread of a non‐fatal disease in a population which is assumed to have constant…
Abstract
Purpose
The purpose of this paper is to solve both the prey and predator problem and the problem of the spread of a non‐fatal disease in a population which is assumed to have constant size over the period of the epidemic.
Design/methodology/approach
The differential transform method (DTM) is employed to compute an approximation to the solutions of the systems of nonlinear ordinary differential equations of these problems.
Findings
Results obtained using the scheme presented here agree well with the results obtained by the Adomian decomposition and power series methods. Some plots are presented to show the reliability and simplicity of the method.
Originality/value
This paper is believed to represent a new application for DTM on solving systems of nonlinear ordinary differential equations.
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Rahul Bansal and Sudipta Majumdar
This paper aims to present the estimation of the output voltage of metal oxide semiconductor field effect transistor (MOSFET) using the extended Kalman filter (EKF) method.
Abstract
Purpose
This paper aims to present the estimation of the output voltage of metal oxide semiconductor field effect transistor (MOSFET) using the extended Kalman filter (EKF) method.
Design/methodology/approach
The method uses EKF for MOSFET output voltage estimation. To implement the EKF method, the state space model has been obtained using Kirchhoff’s current law and Enz-Krummenacher-Vittoz model of the MOSFET circuit.
Findings
The proposed method can be used for any mode of MOSFET operation besides near the quiescent point region. The nonlinearity that occurs in the saturation region of MOSFET can also be considered in the proposed method. The proposed method can also be used for a large input signal. Though Kalman filter can be used for the small amplitude input signal, it results in inaccurate estimation due to the linearization of the nonlinear system.
Research limitations/implications
The method is able to track the parameters when they are slowly changing with time.
Originality/value
The proposed method presents maximal precision of simulation as the maximal precision of simulation requires modeling of the circuit in terms of device parameters and circuit elements.
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M. Inc, Y. Cherruault and K. Abbaoui
Studies an analytic solution and a reliable numerical approximation of linear and non‐linear wave equations by using the Adomian decomposition method. The solution is calculated…
Abstract
Studies an analytic solution and a reliable numerical approximation of linear and non‐linear wave equations by using the Adomian decomposition method. The solution is calculated in the form of a series with easily computable components. The non‐homogeneous problem is quickly solved by observing the self‐cancelling “noise terms” where the sum of the components vanishes in the limit. Several linear or non‐linear partial differential equations are considered and their numerical approximate solutions are compared with its numerical analytic solutions by applying the Adomian decomposition method and using a computer algebraic system (MATLAB). The numerical results show the effectiveness of the method for these types of equations.
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