M. Bank

SCALAR CONSERVATION LAWS ON A HALF-LINE: A PARABOLIC APPROACH

The initial-boundary value problem for the (viscous) nonlinear scalar conservation law is considered, The flux f(ξ) ∈ C2(ℝ) is assumed to be convex (but not strictly convex, i.e. f″(ξ)≥ 0). It is shown that a unique limit u = lim∊ → 0 u∊ exists. The classical duality method is used to prove uniqueness. To this end parabolic estimates for both the direct and dual solutions are obtained. In particular, no use is made of the Kružkov entropy considerations.

Dark spot shift along a vertical line

Use of compensation method for creation of weak field area located above an antenna feed point is considered. Structure comprising two additional radiators, which are placed symmetrically with respect to the straight line passing through a main radiator feed point and a dark spot center and create the same fields, is presented.

A monopole with raised feed point

The field of a finite length monopole whose feed point is raised (sleeve antenna) is calculated. Its behavior is similar to a dipole with two feed points. The mutual coupling between closely located radiators of this type, when used in the compensation method, is considered.

A new effective antenna for mobile headsets

The main problems concerned with the design of mobile headsets antennas treated in this paper are low efficiency and the difficulty of installing two antennas or more for Multiple Input-Multiple Output (MIMO) applications. This paper proposes a radical solution to the mentioned problems by avoiding the use of special antennas as radiating elements. The proposed efficient radiating element is the mobile headset printed circuit board. The proposed solution is compared with other classical solutions.