A class of quadratic minimization problems is studied whose optimal control functions are partially singular. An explicit expression is obtained for the (n − 1)-dimensional singular surface and it is shown that the optimal value function is twice continuously differentiable across this surface; this allows the piecing together of known sufficiency conditions for totally singular and totally bang-bang arcs to obtain sufficient conditions for optimality for this class of partially singular problems. A neighboring optimal feedback control law is suggested by these results. The closing sections of the paper are concerned with sufficient conditions for nonexistence of optimal singular controls in quadratic minimization problems.
This article reports on the development of dry etching technology which will offer the potential to fabricate high aspect ratio structures in silicon for Micro Electro Mechanical Systems (MEMS) fabrication, using chlorine Roshe4471-Shoes Roshe Trainers Women Deep Blue Orange
chemistry. In this study, we report about our investigations on the etching mechanisms using gas chopping technique. Chlorine with BCl3, as chopping gas for scavenging was the basis for deep trench etching in silicon. A Shoes Nike FS Lite Run Men Blue Provider
conventional planar RIE (Reactive Ion Etching) reactor has been used. We optimised the process parameters as per our reactor's configuration to have compromise for best selectivity, anisotropy and high etch rates, which was obtained at BCl3 gas chopping time of 2 to 4 minutes, with DC-bias of −200 to −300 Volts.