Three different reformulations of a free surface problem as shape optimization problems are considered. These give rise to three different cost functionals which apparently have not been exploited in literature. The shape derivatives of the cost functionals are explicitly determined. The gradient information is combined with the boundary variation method in a steepest descent algorithm to solve...

A variable parametrization scheme is developed and demonstrated for shape optimization using quasi-Newton methods. The scheme performs adaptive parametrization refinement while preserving the approximate Hessian of the shape optimization problem and enables free-form shape design using quasi-Newton optimization methods. Using a Bspline parametrization, the scheme is validated using a 1-D shape ...

In this study, we propose a new approach for creating the optimal shape and topology of shell structures. By implementing topology optimization in the variable design domain which is optimized by shape optimization at every iteration, the optimal topology and shape is simultaneously determined. The free-form optimization method and the SIMP method for shells are used for shape and topology opti...

this work intends to deal with the optimal kinematic synthesis problem of tricept parallel manipulator. observing that cuboid workspaces are desirable for most machines, we use the concept of effective inscribed cuboid workspace, which reflects requirements on the workspace shape, volume and quality, simultaneously. the effectiveness of a workspace is characterized by the dexterity of the manip...

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Self-adjoint extensions of elliptic operators are used to model the solution of a partial differential equation defined in a singularly perturbed domain. The asymptotic expansion of the solution of a Laplacian with respect to a small parameter ε is first performed in a domain perturbed by the creation of a small hole. The resulting singular perturbation is approximated by choosing an appropriat...

We are starting to integrate Carnegie Learning’s Cognitive Tutor (CT) into the Army Research Laboratory’s Generalized Intelligent Framework for Tutoring (GIFT), with the aim of extending the tutoring systems to understand the impact of integrating non-cognitive factors into our tutoring. As part of this integration, we focus on ways in which non-cognitive factors can be assessed, measured, and/...

The ability to automatically morph an existing mesh to conform to geometry modifications is a necessary capability to enable rapid prototyping of design variations. This paper compares six methods for morphing hexahedral and tetrahedral meshes, including the previously published FEMWARP and LBWARP methods as well as four new methods. Element quality and performance results show that different m...

This paper investigates changes in the variety and intensity of formal and informal control mechanisms in offshore software development (OSD) projects. Based on a comparative case study approach our results confirm existing findings such as that the amount of control varies across different projects stages, but also contribute with new findings. For example, we found that particularly the quali...

In recent years, the importance of economical considerations in the field of dam engineering has motivated many researchers to propose new methods for minimizing the cost of dames and in particular arch dams. This paper presents a method for shape optimization of double curvature arch dams corresponding to minimum construction cost while satisfying different constraints such as natural frequenc...