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Nonequilibrium and many body effects in the realistic simulation of intersubband emitters

This study gives a short description of nonequilibrium and many body effects in realistic simulation of intersubband emitters. Calculations are based on the self-consistent solution of the quantum kinetic equations under operating steady-state conditions. Scattering with phonons is included by means of a self-energy in the Dyson equation, and electron-electron interaction is treated in mean field

Experiments to Investigate the Effects of Heat Treatment on Use-wear on Flint Tools

A series of twenty controlled experiments was undertaken to determine if heat treatment alters the speed, intensity, or appearance of wear on the edges of flint tools. Four hypotheses were tested with the following results: Heat-treated tools wore more quickly and with more severity than tools which had not been heated. When used in the same fashion and on the same materials, heat-treated flakes s

A channel model for MIMO systems in macro- and microcellular environments

We consider the propagation in macro- and microcellular environments for systems with multiple antennas at both transmitter and receiver. We consider the important propagation effects that lead to (i) interdependency of directions-of-arrival and directions-of-departure, (ii) large delay and angle dispersion by propagation via far clusters, (iii) rank reduction of the transfer function matrix. We p

The development of NEXT STEP beyond Lean Production - The link between technology and economics with focus on sustainable developments

The paper provides a brief presentation of different production philosophies and their characteristics. How the one builds upon the other, and how those characteristics considered to be positive and of strong current interest are taken advantage of by developments underway in any given period are examined. Developmental trends that are evolving (NEXT STEP) or that can serve to complement the Lean

On prediction of MIMO capacity performance with antenna magnitude patterns

This paper considers the impact of phaseless (or magnitude only) output antenna patterns on the performance of multiple antenna systems which employ impedance matching networks. In particular, correlation and capacity are used as performance metrics when the output patterns are with or without phase information. Two methods of synthesizing complex antenna patterns are also discussed and their perf