Further adventures in shape space

Airfoil Shape Optimization with Adaptive Mutation Genetic Algorithm

An efficient method for scattering Genetic Algorithm (GA) individuals in the design space is proposed to accelerate airfoil shape optimization. The method used here is based on the variation of the mutation rate for each gene of the chromosomes by taking feedback from the current population. An adaptive method for airfoil shape parameterization is also applied and its impact on the optimum desi...

Shape Operator of Slant Submanifolds in Kenmotsu Space Forms

Analytical Solution for a Two-Layer Transversely Isotropic Half-Space Affected by an Arbitrary Shape Dynamic Surface Load

The dynamic response of a transversely isotropic, linearly elastic layer bonded to the surface of a half-space of a different transversely isotropic material under arbitrary shape surface loads is considered. With the help of displacements and stresses Green’s functions, an analytical formulation is presented for the determination of the displacements and stresses at any point in both surface l...

Adventures in de Sitter space

This is my contribution to the Festschrift honoring Stephen Hawking on his 60th birthday. Twentyfive years ago, Gibbons and Hawking laid out the semi-classical properties of de Sitter space. After a summary of their main results, I discuss some further quantum aspects that have since been understood. The largest de Sitter black hole displays an intriguing pattern of instabilities, which can ren...

Efficient Delay Characterization Method to Obtain the Output Waveform of Logic Gates Considering Glitches

Accurate delay calculation of circuit gates is very important in timing analysis of digital circuits. Waveform shapes on the input ports of logic gates should be considered, in the characterization phase of delay calculation, to obtain accurate gate delay values. Glitches and their temporal effect on circuit gate delays should be taken into account for this purpose. However, the explosive numbe...