Revisited LQ output-feedback control: minimax controller for a set of initial states

A minimax linear quadratic (LQ) output-feedback controller is introduced which minimises the maximal value of the performance index over all initial states belonging to some set separated out a priori. If the set is an ellipsoid or a polygon, such controllers are synthesised in terms of linear matrix inequalities (LMIs). In particular case when a size of this set tends to zero tightening to a point, the minimax LQ controller approaches the optimal LQ output-feedback controller for the given initial state, while in another extreme case when this size tends to infinity, we have the worst-case LQ output-feedback controller. Numerical results for an inverted pendulum are presented.     

3D vector tomography using vector spherical harmonics decomposition

The article presents the reconstruction method of the flow fields from vector tomography passive ion Doppler spectroscopy in a plasma experiment. The method is based on series expansion in terms of vector spherical harmonics for volumetric, divergent-free vector fields and intended for three-dimensional diagnostic in the spherical tokamak devices. An inversion of spectral experimental data is known in tomography as an inversion of vectorial ray transform. The relation of the vectorial ray transform with Doppler spectroscopy measurements are given in Balandin and Ono (2001, 2003) [7], [8]. The effectiveness of the proposed method is tested on a range of model 3D divergent-free vector fields.     

Diffusion zincing in fluidized bed

Process of diffusion zincing of steel St3 in a fluidized bed are compared with conventional diffusion zincing. Acomparative analysis of the phase composition, microhardness, microbrittleness, porosity, and corrosion resistance of diffusion zirconium layers is performed. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 4, pp. 37–39, April, 2006.     

Synthesis of nonfragile controllers on the basis of linear matrix inequalities

The notion of a nonfragile controller is introduced that affords the fulfillment of the aim of control at variations of its parameters from a definite class. Synthesis of nonfragile stabilizing controllers in the state and the output is carried out on the basis of linear matrix inequalities and an algorithm for the search of mutually inverse matrices.     

Nanoscale thermal management

Here the author outlines only a few nanoscale phenomena that adversely affect thermal conductivity and can complicate heat removal from nanoscale electronic devices. Since progress in the electronic industry is largely associated with device down-scaling, he considers that research on this subject is worth pursuing     

Effect of heat treatment on the structure and proneness to embrittlement of oxidation-resistant ferritic steel 02Kh18Yu3B

Conclusion To obtain a fine-grained, equiaxial structure of the ferritic steel 02Kh18Yu3B after hot rolling, the regime of the subsequent heat treatment has to be suitably chosen. The strongly textured structure of hot-rolled sheet of steel 02Kh18Yu3B can be corrected by heating the steel to 900°C, holding for 1 h, and cooling in water; the impact toughness of the steel then increases, and the critical brittle temperature shifts toward lower temperatures.Scientific and Production Association of the Central Research Institute of Engineering Technology (NPO TsNIITMASh). Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 4, pp. 54–56, April, 1983.