In a classical problem for the stopping of diffusion process ( X t ) ? 0 , where goal is to maximise expected discounted value function stopped E x [ e ? ? ? g ] maximisation takes place over all times . Poisson optimal problem, restricted event an independent process. this article we consider whether resulting V ? = sup ? T (where supremum taken taking values in inhomogeneous with rate inherit...

A new minimally invasive surgical technique for lumbar spine fixation is currently in development. The procedure makes use of an interbody implant that is inserted between two vertebral bodies. The implant is packed with bone graft material that fuses the motion segment. The implant must be capable of retaining bone graft material and supporting spinal loads while fusion occurs. The different l...

Optimization problems involving millions of variables arise in three classes of applications: optimal control, inverse problems and shape optimization. In all these cases the simulation requires the solution of 3D partialdifferential equations, which must be peformed using parallel computing environments. We will present case studies illustrating the state-of-the-art of this field, which is oft...

Shape recognition is a classically difficult problem because of the affine transformation between two shapes. The current study proposes an affine parameter estimation method for shape recognition based on a genetic algorithm (GA). The contributions of this study are focused on the extraction of affineinvariant features, the individual encoding scheme, and the fitness function construction poli...

The topological derivative is defined as the first term of the asymptotic expansion of a given shape functional with respect to a small parameter that measures the size of a singular domain perturbation. It has applications in many different fields such as shape and topology optimization, inverse problems, image processing and mechanical modeling including synthesis and/or optimal design of mic...

A viscous discrete adjoint approach to automatic aerodynamic shape optimization is developed, and the merits of the viscous discrete and continuous adjoint approaches are discussed. The viscous discrete and continuous adjoint gradients for inverse design and drag minimization cost functions are compared with finite-difference and complex-step gradients. The optimization of airfoils in two-dimen...

We consider shape optimization problems governed by the unsteady Navier-Stokes equations by applying the method of mappings, where the problem is transformed to a reference domain Ωref and the physical domain is given by Ω = τ(Ωref) with a domain transformation τ ∈ W (Ωref). We show the Fréchet-differentiability of τ 7→ (v, p)(τ) in a neighborhood of τ = id under as low regularity requirements ...

Multiple frequencies constraints and analytical sensitivity methods were used in structural optimization design of the side plate of 4YK1860 vibrating screen to lower the damage of side plate caused by high dynamic stress. The mass of side plate of the vibrating screen was taken as object function, mode frequencies were regarded as state parameters, size of plate were used as constraint paramet...