Families of regimes for control systems are studied possessing the so called quasi–control-lability property that is similar to the Kalman control lability property. A new approach is proposed to estimate the degree of transients overshooting in quasi–controllable systems. This approach is conceptually related with the principle of bounded regimes absence in the absolute stability problem. Its ...

Quasi-stationary distributions, as discussed by Darroch & Seneta (1965), have been used in biology to describe the steady state behaviour of population models which, while eventually certain to become extinct, nevertheless maintain an apparent stochastic equilibrium for long periods. These distributions have some drawbacks: they need not exist, nor be unique, and their calculation can present p...

Complex surface structures have stimulated a great deal of interests due to many potential applications in surface devices. However, in the fabrication of complex surface micro-/nanostructures, there are always great challenges in precise design, or good controllability, or low cost, or high throughput. Here, we present a route for the accurate design and highly controllable fabrication of surf...

We investigate crossed products of Cuntz algebras by quasi-free actions of abelian groups. We prove that our algebras are AF-embeddable when actions satisfy a certain condition. We also give a necessary and sufficient condition that our algebras become simple and purely infinite, and consequently our algebras are either purely infinite or AF-embeddable when they are simple.

An affine Toda-Sutherland system is a quasi-exactly solvable multi-particle dynamics based on an affine simple root system. It is a ‘cross’ between two well-known integrable multi-particle dynamics, an affine Toda molecule and a Sutherland system. Polynomials describing the equilibrium positions of affine Toda-Sutherland systems are determined for all affine simple root systems.

97 There are several contexts in which randomization in research design is not possible. Researchers may be interested in the effects of large-scale events or policy initiatives, or of complex causal processes that cannot be replicated. Threats to external validity in randomized experiments will lead to greater dividends for some research questions in a quasi-experimental design. Quasi-experime...