An asymptotically optimal model for isotropic heterogeneous linearly elastic plates

In this paper, we derive and analyze a Reissner-Mindlin-like model for isotropic heterogeneous linearly elastic plates. The modeling procedure is based on a Hellinger-Reissner principle, which we modify to derive consistent models. Due to the material heterogeneity, the classical polynomial profiles for the plate shear stress are replaced by more sophisticated choices, that are asymptotically correct. In the homogeneous case we recover a Reissner-Mindlin model with 5/6 as shear correction factor. Asymptotic expansions are used to estimate the modeling error. We remark that our derivation is not based on asymptotic arguments only. Thus, the model obtained is more sophisticated (and accurate) than simply taking the asymptotic limit of the three dimensional problem. Moreover, we do not assume periodicity of the heterogeneities

Final-state, Open-loop Control of the Heat equation in Tensorial Domains (full version)

In this paper, a quadratic optimal control problem will be considered for the heat equation in tensorial domains with homogeneous Dirichlet boundary conditions, in which the control function (depending only on time) constitutes a source term. These problems involve choosing a control function (with or without "peak-value" constraints) to approximately steer the solution of the heat equation to a desired function at the end of a prescribed (finite) time-interval. To compute approximations to the desired optimal control functions, semi-discrete, spectral (with eigenfunctions) Galerkin approximations to the corresponding heat equation and the corresponding (approximating) control problems are tackled. Two simple, illustrative examples are presented in the final section.Comment: 32 pages, 11 figures, submitte

Operations and control of unmanned underwater vehicles

Operations and control of unmanned underwater vehicle systems arediscussed in terms of systems and technologies, vehicles, operational deploymentsand concepts of operation. The notions underlying the specification of single vehicleoperations are contrasted to new concepts of operation to illustrate the challengesthey pose to control engineering. New research directions are discussed in thecontext of the theories and techniques from dynamic optimization and computerscience. The overall discussion is done in the context of the activities of theUnderwater Systems and Technology Laboratory from Porto University

description of the methodological approach

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