The U.S. role in global internet governance

Who should control the Internet? A dozen years after the Internet became a mass medium, this issue has continued to grow in urgency, becoming white hot in fall 2005. At the September 2005 preparatory meeting for the UN World Summit on the Information Society (WSIS), a coalition of countries criticized the United States' unilateral control of the Internet's domain name system (DNS) and proposed the establishment of a multinational Council to supervise it. This proposal emerged from the Final Report of the UN Working Group on Internet Governance. Researchers from the Internet Governance Project, a university-based consortium for policy analysis, have concluded that the United States should internationalize governance of the Internet, but in a way that avoids intrusive, centralized control.     

Recurrence vs. transience for spatially inhomogeneous birth and death in a random environment

Summary We consider birth and death in a random environment, having probabilitiesp(,x) andq(,x) of a step to the right or left, respectively, from statex in environment. Under several sets of conditions involving the existence of limp(,x) and limq(,x) asx, we give conditions for certain extinction or escape to when 0 is absorbing, corresponding to recurrence or transience when 0 is reflecting. The environmental sequence is assumed to be stationary ergodic, and for some results stronger assumptions are required.     

A stochastic theory of adiabatic invariance

LetI be a set of invariants for a system of differential equations with an ordero() vector field. When order perturbations of zero mean are added to the system we show that, under suitable regularity and ergodicity conditions,I becomes an adiabatic invariant with maximal variations of order one on time scales of order 1/². In the stochastically perturbed case,I behaves asymptotically (for small ) like a diffusion process on 1/² time scales. The results also apply to an interesting class of deterministic perturbations. This study extends the results of Khas'minskii on stochastically averaged systems, as well as some of the deterministic methods of averaging, to such invariants.Supported by NSF grant DMR-8704348     

New Layered Intergrowths in the Sn-Mo-Se System

Several new metastable layered intergrowths based on tin monoselenide and molybdenum diselenide, [(SnSe)_1+?? ] _m [MoSe₂] _n , have been prepared by self-assembly from elemental nanolaminate precursors deposited by physical vapor deposition. The thin-film specimens were characterized by laboratory x-ray reflectivity and diffraction, synchrotron x-ray diffraction, electron probe microanalysis, and scanning transmission electron microscopy techniques, all of which indicate the formation of intergrowths with precise layering and well-defined composition. Analysis of in-plane diffraction originating from the individual components yields a structural misfit of ???=?0.06 and suggests turbostratic misorientation of the individual layers. In contrast to most known [(MX)_1+?? ] _m [TX₂] _n -type chalcogenide compounds, electrical transport data for the [(SnSe)_1+?? ]₁[MoSe₂]₁ composition are consistent with semiconducting behavior.     

Petroleum und Petroleumkohlenwasserstoffe

Ohne Zusammenfassung     

The ergodic theory of Markov chains in random environments

Summary A general formulation of the stochastic model for a Markov chain in a random environment is given, including an analysis of the dependence relations between the environmental process and the controlled Markov chain, in particular the problem of feedback. Assuming stationary environments, the ergodic theory of Markov processes is applied to give conditions for the existence of finite invariant measure (equilibrium distributions) and to obtain ergodic theorems, which provide results on convergence of products of random stochastic matrices. Coupling theory is used to obtain results on direct convergence of these products and the structure of the tail -field. State properties including classification and communication properties are discussed.     

A four-thirds law for phase randomization of stochastically perturbed oscillators and related phenomena

LetI be a set of invariants and be a set of angle variables for a system of differential equations with anO() vector field. When time dependent stochastic perturbations, also ofO(), are added to the system, we have shown that under suitable conditionsI becomes a stochastic adiabatic invariant satisfying a diffusion equation on time scales of order 1/², in the limit as »0. Here we show that the angle variables converge weakly to a Gaussian Markov process on an O(^-4/3) time scale, and thus the phase becomes randomized at these times. Application to nearly integrable Hamiltonian systems is considered.Supported by NSF grant DMR-8704348     

Birth and death processes with random environments in continuous time

"A generalization to continuous time is given for a discrete-time model of a birth and death process in a random environment. Some important properties of this process in the continuous-time setting are stated and proved including instability and extinction conditions, and when suitable absorbing barriers have been defined, methods are given for the calculation of extinction probabilities and the expected duration of the process."