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To design a robust attitude control system for the ascent flight phase of satellite launch vehicles (SLVs).

The autopilot is based on generalized dynamic inversion (GDI). Dynamic constraints are prescribed in the form of differential equations that encapsulate the control objectives, and are generalized inverted using the Moore-Penrose Generalized Inverse (MPGI) based Greville formula to obtain the control law. The MPGI is modified via a dynamic scaling factor for assuring generalized inversion singularity-robust tracking control. An additional sliding mode control (SMC) loop is augmented to robustify the GDI closed-loop system against model uncertainties and external disturbances.

The robust GDI control law allows for two cooperating controllers that act on two orthogonally complement control spaces: one is the particular controller that realizes the dynamic constraints, and the other is the auxiliary controller that is affined in the null control vector, and is used to enforce global closed-loop stability.

Orthogonality of the particular and the auxiliary control subspaces ensures noninterference of the two control actions, and thus, it ensures that both actions work toward a unified goal. The robust control loop increases practicality of the GDI control design.

The first successful implementation of GDI to the SLV control problem.

The purpose of this paper is to clarify the dynamic principle of internal structure of a complex morphing wing and control the wing to change configurations rapidly and smoothly. It includes modeling the dynamics of the morphing wing and designing a rational morphing control system.

The dynamic model of the morphing wing is developed based on Lagrange method of analytical mechanics. The generalized forces are obtained by virtual work principle. Since the morphing wing is a strongly coupled, over‐actuated and nonlinear system with multi‐input and multi‐output, the control system design includes a control allocator, a dynamic inversion controller and two PID controllers. The control allocator is designed based on pseudo inverse method; the dynamic inversion controller is applied to make the original system decoupled into two independent linear systems by proper nonlinear feedback transformation; two classical PID controllers are adopted for the linearlized systems.

The validity of the dynamic model and the controller is verified according to the simulation results using ADAMS and Matlab. It suggests that integrating Lagrange equation, pseudo inverse allocation, dynamic inversion control and classical PID method, is an effective way to solve problems of dynamic modeling and control for morphing wings.

The flexibility of the structure, the changes of the aerodynamic load, the mass and the dynamic performances of actuators are not taken into account. Therefore, researchers are encouraged to develop a more realistic morphing wing model.

The paper includes implications for the development of a dynamic model of a complex morphing wing and a rational morphing control system.

The paper fulfils a complete process from multi‐rigid‐body dynamic modeling to control system design for an over‐actuated nonlinear complex morphing wing, which could be a foundation of further researches on morphing wing dynamics and control.

In the current study, corporate investment is examined by using a user cost of capital model for two important Latin American economies: Brazil and Mexico. In this paper, a dynamic user cost of capital model is employed. The extended model also accounts the investment model with the convex adjustment cost. Moreover, the link between structural change, financial liberalization and investment is also investigated. The present study, therefore, sheds new lights on the investment behavior of the Latin American emerging markets.

The differenced generalized method of moments approach is employed to control the endogeneity, heteroscedasticity and autocorrelation for modeling the corporate investment over 20 years for both countries.

The findings indicate that the dynamic user cost of capital-based investment model explains the corporate investment in Brazil and Mexico. Especially, the interest rate and depreciation explain the investment behavior of nonfinancial firms in both countries. At the same time, structural change and financial liberalization do not have a significant impact on interest rates, an important user cost of capital.

This is the first study examines the corporate investment using dynamic user costs of capital approach for an emerging market. The user cost of capital-based investment models is clearly understudied models for emerging markets. This study is particularly important for emerging markets as investment models need to have a theoretical background.

En el presente estudio se examina la inversión empresarial utilizando un modelo de coste de capital del usuario para dos importantes economías latinoamericanas: Brasil y México. En este trabajo se emplea un modelo dinámico de coste de capital para el usuario. El modelo ampliado también tiene en cuenta el modelo de inversión con el coste de ajuste convexo. Además, se investiga la relación entre el cambio estructural, la liberalización financiera y la inversión. El presente estudio, por tanto, arroja nueva luz sobre el comportamiento de la inversión en los mercados emergentes latinoamericanos.

Se emplea el método GMM diferenciado para controlar la endogeneidad, la heteroscedasticidad y la autocorrelación en la modelización de la inversión empresarial a lo largo de 20 años en ambos países.

Los resultados indican que el modelo dinámico de inversión basado en el coste de capital para el usuario explica la inversión empresarial en Brasil y México. Especialmente, el tipo de interés y la depreciación explican el comportamiento de la inversión de las empresas no financieras en ambos países. Al mismo tiempo, se constata que el cambio estructural y la liberalización financiera no tienen un efecto significativo sobre los tipos de interés, que es un importante coste de uso del capital.

Este es el primer estudio que examina la inversión empresarial utilizando un enfoque dinámico basado en los costes de capital para un mercado emergente. Los modelos de inversión basados en los costes de uso del capital son claramente modelos poco estudiados para los mercados emergentes. Este estudio es especialmente importante para los mercados emergentes, ya que los modelos de inversión deben tener un trasfondo teórico.

A computational procedure is presented for the efficient non‐linear dynamic analysis of quasi‐symmetric structures. The procedure is based on approximating the unsymmetric response vectors, at each time step, by a linear combination of symmetric and antisymmetric vectors, each obtained using approximately half the degrees of freedom of the original model. A mixed formulation is used with the fundamental unknowns consisting of the internal forces (stress resultants), generalized displacements and velocity components. The spatial discretization is done by using the finite element method, and the governing semi‐discrete finite element equations are cast in the form of first‐order non‐linear ordinary differential equations. The temporal integration is performed by using implicit multistep integration operators. The resulting non‐linear algebraic equations, at each time step, are solved by using iterative techniques. The three key elements of the proposed procedure are: (a) use of mixed finite element models with independent shape functions for the stress resultants, generalized displacements, and velocity components and with the stress resultants allowed to be discontinuous at interelement boundaries; (b) operator splitting, or restructuring of the governing discrete equations of the structure to delineate the contributions to the symmetric and antisymmetric vectors constituting the response; and (c) use of a two‐level iterative process (with nested iteration loops) to generate the symmetric and antisymmetric components of the response vectors at each time step. The top‐ and bottom‐level iterations (outer and inner iterative loops) are performed by using the Newton—Raphson and the preconditioned conjugate gradient (PCG) techniques, respectively. The effectiveness of the proposed strategy is demonstrated by means of a numerical example and the potential of the strategy for solving more complex non‐linear problems is discussed.

This paper presents a new simplified text of some concepts of pansystems methodology and related applications to pedagogy, methods of teaching, study and creation, including certain principles of operations research, systems theory, cybernetics, etc.

The purpose of this paper is to study the deformation of a rotating generalized thermoelastic medium with two temperatures under hydrostatic initial stress subjected to different types of sources.

The methodology applied here is the use of integral transforms to obtain the components of displacement, force stress, conductive temperature and temperature distribution in Laplace and Fourier domain. The general solution obtained is applied to a specific problem of a half‐space subjected to concentrated force, uniformly distributed force and a moving source. These components are then obtained in the physical domain by applying a numerical inversion method. Some particular cases are also discussed in the context of the problem. The results obtained are also presented graphically to show the effect of rotation and gravity.

The variations of all the quantities and for all the mediums are similar for concentrated force and distributed forces applied along the free surface of the solid. The values of these quantities are very close to each other for GTES and GTESWG. Deformation of a body depends on the nature of force applied as well as the type of boundary conditions. The variations of all the quantities are more uniform in nature when a force of constant magnitude moves along the surface of solid with some velocity.

Such types of problems in rotating media will find great applications in many dynamical systems and industries.

A dynamical two‐dimensional problem of a homogeneous transversely isotropic fibre‐reinforced generalized thermoelastic solid with an overlying acoustic fluid layer has been considered to investigate disturbance due to mechanical load. Laplace and Fourier transform techniques are applied to solve the problem. Uniformly distributed and linearly distributed forces are applied to illustrate the utility of the approach. A numerical inversion technique has been applied to obtain the solution in the physical domain. Numerical results are obtained and presented graphically to show the effect of anisotropy along with the comparison of homogeneous transversely isotropic fibre‐reinforced generalized thermoelastic solid and isotropic elastic solid.

The present work is concerned with the solution of a fractional-order thermoelastic problem of a two-dimensional infinite half space under axisymmetric distributions in which lower surface is traction free and subjected to a periodically varying heat source. The thermoelastic displacement, stresses and temperature are determined within the context of fractional-order thermoelastic theory. To observe the variations of displacement, temperature and stress inside the half space, the authors compute the numerical values of the field variables for copper material by utilizing Gaver-Stehfast algorithm for numerical inversion of Laplace transform. The effects of fractional-order parameter on the variations of field variables inside the medium are analyzed graphically. The paper aims to discuss these issues.

Integral transform technique and Gaver-Stehfast algorithm are applied to prepare the mathematical model by considering the periodically varying heat source in cylindrical co-ordinates.

This paper studies a problem on thermoelastic interactions in an isotropic and homogeneous elastic medium under fractional-order theory of thermoelasticity proposed by Sherief (Ezzat and El-Karamany, 2011b). The analytic solutions are found in Laplace transform domain. Gaver-Stehfast algorithm (Ezzat and El-Karamany, 2011d; Ezzat, 2012; Ezzat, El Karamany, Ezzat, 2012) is used for numerical inversion of the Laplace transform. All the integrals were evaluated using Romberg’s integration technique (El-Karamany et al., 2011) with variable step size. A mathematical model is prepared for copper material and the results are presented graphically with the discussion on the effects of fractional-order parameter.

Constructed purely on theoretical mathematical model by considering different parameters and the functions.

The system of equations in this paper may prove to be useful in studying the thermal characteristics of various bodies in real-life engineering problems by considering the time fractional derivative in the field equations.

In this problem, the authors have used the time fractional-order theory of thermoelasticity to solve the problem for a half space with a periodically varying heat source to control the speed of wave propagation in terms of heat and elastic waves for different conductivity like weak conductivity, moderate conductivity and super conductivity which is a new and novel contribution.

The purpose of this paper is to describe two‐ and three‐dimensional numerical modelling of solid oxide fuel cells (SOFCs) by employing an accurate and stable fully matrix inversion free finite element algorithm.

A general and detailed mathematical model has been developed for the description of the coupled complex phenomena occurring in fuel cells. A fully matrix inversion free algorithm, based on the artificial compressibility (AC) version of the characteristic‐based split (CBS) scheme and single domain approach have been successfully employed for the accurate and efficient simulation of high temperature SOFCs.

For the first time, a stable fully explicit algorithm has been applied to detailed multi‐dimensional simulation transport phenomena, coupled to chemical and electrochemical reactions, in fluid, porous and solid parts of a SOFC. The accuracy of the present results has been verified via comparison with experimental and numerical data available in the literature.

For the first time, thanks to a stabilization analysis conducted, the AC‐CBS algorithm has been successfully used to numerically solve the generalized model, applied in this paper to describe transport phenomena through free fluid channels and porous electrodes of SOFCs, without the need of further conditions at the fluid‐electrode interface.

The purpose of this paper is to present an efficient method for dynamic analysis of structures utilizing a modal analysis with the main purpose of decreasing the computational complexity of the problem. In traditional methods, the solution of initial-value problems (IVPs) using numerical methods like finite difference method leads to step by step and time-consuming recursive solutions.

The present method is based on converting the IVP into boundary-value problems (BVPs) and utilizing the features of the latter problems in efficient solution of the former ones. Finite difference formulation of BVPs leads to matrices with repetitive tri-diagonal and block tri-diagonal patterns wherein the eigensolution and matrix inversion are obtained using graph products rules. To get advantage of these efficient solutions for IVPs like the dynamic analysis of single DOF systems, IVPs are converted to boundary-value ones using mathematical manipulations. The obtained formulation is then generalized to the multi DOF systems by utilizing modal analysis.

Applying the method to the modal analysis leads to a simple and efficient formulation. The laborious matrix inversion and eigensolution operations, of computational complexities of O(n2.373) and O(n3), respectively, are converted to a closed-form formulation with summation operations.

No limitation.

Swift analysis has become possible.

Suitability of solving IVPs and modal analysis using conversion and graph product rules is presented and applied to efficient seismic optimal analysis and preliminary design.