Other Computational Technique for Estimation of Lower Bound on Capacity of Two-Dimensional Diamond-1 Constrained Channel

Computational technique for lower bound on Two-dimensional Diamond-1 constrained channel capacity is presented in this paper. It is basically an amalgamation of Matrix Fractal Grow Method (MFGM) and a new Matrix Fractal Reduction Method both applicable to state transition matrices of the corresponding constrained channels and Rayleigh Quotient Iteration method. Also other programming tricks are presented which improve its implementation. Estimation of lower bound values on the mentioned capacity is made using it. The results are in good alignment with known exact results, which is a verification of the new method. The method could be generalized for other constraints which are restricted only on one neighbor symbol in 2D constrained channel such as for example Square-1 and Hexagonal-1

Electrical Swath Ships with Underwater Hulls Preventing the Boundary Layer Separation

The body shapes of aquatic animals can ensure a laminar flow without boundary layer separation at rather high Reynolds numbers. The commercial efficiencies (drag-to-weight ratio) of similar hulls were estimated. The examples of neutrally buoyant vehicles of high commercial efficiency were proposed. It was shown that such hulls can be effectively used both in water and air. In particular, their application for SWATH (Small Water Area Twin Hulls) vehicles is discussed. In particular, the seakeeping characteristics of such ships can be improved due to the use of underwater hulls. In addition, the special shaping of these hulls allows the reducing of total drag, as well as the energetic needs and pollution. The presented estimations show that a weight-to-drag ratio of 165 can be achieved for a yacht with such specially shaped underwater hulls. Thus, a yacht with improved underwater hulls can use electrical engines only, and solar cells to charge the batteries