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Two-dimensional Systems (two-dimensional + system)

Distribution by Scientific Domains

Physics and Astronomy	50%

Selected Abstracts

DISCRETIZED SUB-OPTIMAL TRACKER FOR NONLINEAR CONTINUOUS TWO-DIMENSIONAL SYSTEMS

ASIAN JOURNAL OF CONTROL, Issue 3 2004
Chia-Wei Chen
ABSTRACT The discretized quadratic sub-optimal tracker for nonlinear continuous two-dimensional (2-D) systems is newly proposed in this paper. The proposed method provides a novel methodology for indirect digital redesign for nonlinear continuous 2-D systems with a continuous performance index. This includes the following features: (1) the 2-D optimal-linearization approach of the nonlinear 2-D Roesser's model (RM), (2) the dynamic programming-based discretized quadratic optimal tracker for linear continuous 2-D systems, (3) the steady-state discretized quadratic sub-optimal tracker for linear continuous 2-D systems, and (4) the discretized quadratic sub-optimal tracker for nonlinear continuous 2-D systems. Illustrative examples are presented to demonstrate the effectiveness of the proposed procedure. [source]

Light emission from different ZnO junctions and nanostructures

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 5 2009
M. Willander
Abstract We will discuss our experimental results for optical spectra produced by hole-injection from different p-type organic and inorganic materials into n-type ZnO nanowires. The influence of different growth techniques and conditions on the nanowires and their emission spectral characteristics will then be analyzed and discussed. The latest findings on the mixture of the green emission band responsible for visible light emission from ZnO and the blue light emission from the organic polymer will be presented. Different high brightness light emitting diodes (HB-LEDs) from our grown ZnO nanowires are demonstrated. The p-type multi layer organic structures contain PEDOT:PSS as hole injectors combined with a hole transporting layer, and in some structures, a final top electron blocking/hole barrier stepping layer is placed. The purpose of this layer is to adjust the hole and electron emission from the corresponding junction side to optimize the LED performance. Structural scanning electron microscopy (SEM), electrical (I ,V characteristics), photoluminescence (PL) and electroluminescence (EL) characteristics of these devices are displayed. Theoretically, we study the superfluidity of a two-dimensional system of excitonic polaritons in an optical microcavity with an embedded quantum well. Using the effective low-energy action for thermodynamic phase fluctuations, we obtain an expression for the analogue of the superfluid density in the system in terms of the "current,current" correlation function. The Kosterlits,Thouless transition temperature to the superfluid state as a function of the controlling parameters is calculated. Two methods are considered for producing traps for a polariton system in an optical microcavity. The behaviour of a two-component Bose condensate of photons and excitons is analyzed theoretically for both types of the trap. The Bose condensate is described by the coupled system of equations of the Gross,Pitaevskii type. The approximate wave functions and the spatial profiles of coupled photon and exciton condensates are obtained. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Interaction effects in high-mobility two-dimensional electron and hole systems

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 6 2005
A. K. Savchenko
Abstract Electron,electron interaction in the presence of impurities is studied in two-dimensional systems where the parameter kBT,/, changes from 0.1 to 10 (, is the momentum relaxation time). This corresponds to the intermediate and ballistic regimes of electron interaction. We analyse the interaction correction to the Drude conductivity in terms of recent theories and show that it is strongly dependent on the character of the impurity potential. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Strongly autonomous interconnections and stabilization of 2D behaviors,

ASIAN JOURNAL OF CONTROL, Issue 2 2010
Diego Napp
Abstract In this paper we study linear discrete two-dimensional systems in the behavioral context where control is viewed as interconnection. Within this framework the natural concept of regular interconnection has been introduced by J.C.Willems. Here we investigate regular interconnections that yield finite dimensional behaviors using tools previously developed to analyze almost implementation problems. We prove that when a finite dimensional (sub-) behavior can be achieved from a given behavior by regular interconnection then the controllable part of the original behavior is rectifiable, moreover, in this case all the other sub-behaviors are almost regularly implementable. We apply these results to characterize all stabilizable behaviors. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source]