Computer Engineering Commons^™

Theory Of Photon Coincidence Statistics In Photon-Correlated Beams, Majeed M. Hayat, Sergio N. Torres, Leno M. Pedrotti

Electrical and Computer Engineering Faculty Research and Publications

The statistics of photon coincidence counting in photon-correlated beams is thoroughly investigated considering the effect of the finite coincidence resolving time. The correlated beams are assumed to be generated using parametric downconversion, and the photon streams in the correlated beams are modeled by two partially correlated Poisson point processes. An exact expression for the mean rate of coincidence registration is developed using techniques from renewal theory. It is shown that the use of the traditional approximate rate, in certain situations, leads to the overestimation of the actual rate. The error between the exact and approximate coincidence rates increases as the …

System And Method For Improving Data Acquisistion Capability In Spectroscopic Rotatable Element, Rotating Element, Modulation Element, And Other Ellipsometer And Polarimeter And The Like Systems, Steven E. Green, Craig M. Heringer, Blaine D. Johs, John A. Woollam, Stephen P. Ducharme

Department of Electrical and Computer Engineering: Faculty Publications

Disclosed is a System and method for controlling polarization State determining parameters of a polarized beam of light in an ellipSometer or polarimeter and the like System, (e.g. a modulation element ellipsometer System), So that they are in ranges wherein the Sensitivity, (of a Sample system characterizing PSI and DELTA value monitoring detector used to measure changes in Said polarization State resulting from interaction with a “composite Sample System,” comprised of a Sample System per Se.. and a beam polarization State determining variable retarder, to noise and measurement errors etc. therein), is reduced. The present invention allows determining Sample System …

Guest Editorial: Special Section On Acousto-Optic Devices And Optical Information Processing: Research And Developments, Partha P. Banerjee, Ting-Chung Poon

Electrical and Computer Engineering Faculty Publications

This guest editorial provides an overview of the topical area and an introduction to the articles featured in the special section.

Laser Beam Profile Deformation Effect During Bragg Acousto-Optic Interaction: A Non-Paraxial Approximation, Ray S. Huang, Chen-Wen Tarn, Partha P. Banerjee, Doungchin Cao

Electrical and Computer Engineering Faculty Publications

It is commonly known that the spatial profiles of the diffracted light beams during Bragg acousto-optic interaction are distorted due to the Bragg angle selection mechanism. All the conventional studies on this effect use the paraxial approximation. But this approximation should be amended when the incident angle of the light is large enough that the diffracted light waves do not propagate closely along the optic axis of the acousto-optic diffraction system. By using a spatial Fourier transform approach, we rigorously study the light beam profile deformation effect of the diffracted light during the Bragg acousto-optic interaction beyond the paraxial approximation. …

Examination Of Beam Propagation In Misaligned Holographic Gratings And Comparison With The Acousto-Optic Transfer Function Model For Profiled Beams, Monish Ranjan Chatterjee, David D. Reagan

Electrical and Computer Engineering Faculty Publications

A transfer function formalism developed earlier for the propagation of profiled optical beams through acousto-optic Bragg cells is revisited and applied to a thick holographic grating. The results based on the holographic coupled wave model and the acousto-optic multiple scattering model are shown to be compatible, and equivalent parameters such as the Q and grating strength are defined for the two systems. Results for a Gaussian spatial profile are numerically computed and compared. For the holographic grating, a profiled beam may be interpreted as an angular misalignment or Bragg-angle mismatch problem. The case of Bragg-wavelength mismatch is also investigated for …

An Analytical Approximation For The Excess Noise Factor Of Avalanche Photodiodes With Dead Space, Majeed M. Hayat, Zikuan Chen, Mohammad Rezaul Karim

Electrical and Computer Engineering Faculty Research and Publications

Approximate analytical expressions are derived for the mean gain and the excess noise factor of avalanche photodiodes including the effect of dead space. The analysis is based on undertaking a characteristic-equation approach to obtain an approximate analytical solution to the existing system of recurrence equations which characterize the statistics of the random multiplication gain. The analytical expressions for the excess noise factor and the mean gain are shown to be in good agreement with the exact results obtained from numerical solutions of the recurrence equations for values of the dead space reaching up to 20% of the width of the …

Constructive Induction Machines For Data Mining, Marek Perkowski, Stanislaw Grygiel, Qihong Chen, Dave Mattson

Electrical and Computer Engineering Faculty Publications and Presentations

"Learning Hardware" approach involves creating a computational network based on feedback from the environment (for instance, positive and negative examples from the trainer), and realizing this network in an array of Field Programmable Gate Arrays (FPGAs). Computational networks can be built based on incremental supervised learning (Neural Net training) or global construction (Decision Tree design). Here we advocate the approach to Learning Hardware based on Constructive Induction methods of Machine Learning (ML) using multivalued functions. This is contrasted with the Evolvable Hardware (EHW) approach in which learning/evolution is based on the genetic algorithm only.

Performance Analysis Of Tcp Enhancements In Satellite Data Networks, Ren H. Broyles

Theses and Dissertations

This research examines two proposed enhancements to the well-known Transport Control Protocol (TCP) in the presence of noisy communication links. The Multiple Pipes protocol is an application-level adaptation of the standard TCP protocol, where several TCP links cooperate to transfer data. The Space Communication Protocol Standard - Transport Protocol (SCPS-TP) modifies TCP to optimize performance in a satellite environment. While SCPS-TP has inherent advantages that allow it to deliver data more rapidly than Multiple Pipes, the protocol, when optimized for operation in a high-error environment, is not compatible with legacy TCP systems, and requires changes to the TCP specification. This …

Complete Maps Of The Aspect Sensitivity Of Vhf Atmospheric Radar Echoes, R. M. Worthington, R. D. Palmer, S. Fukao

Department of Electrical and Computer Engineering: Faculty Publications

Using the MU radar at Shigaraki, Japan (34.85°N, 136.10°E), we measure the power distribution pattern of VHF radar echoes from the mid-troposphere. The large number of radar beam-pointing directions (320) allows the mapping of echo power from 0° to 40° from zenith, and also the dependence on azimuth, which has not been achieved before at VHF wavelengths. The results show how vertical shear of the horizontal wind is associated with a definite skewing of the VHF echo power distribution, for beam angles as far as 30° or more from zenith, so that aspect sensitivity cannot be assumed negligible at any …

Reduction Of Quantum Noise In Transmittance Estimation Using Photonecorrelated Beams, Majeed M. Hayat, Adel Joobeur, Bahaa E.A. Saleh

Electrical and Computer Engineering Faculty Research and Publications

The accuracy of optical measurements at low light levels is limited by the quantum noise of the source and by the random nature of the interaction with the measured object. The source noise may be reduced by use of nonclassical photon-number squeezed light. This paper considers the use of two photon-correlated beams (generated, for example, by spontaneous parametric downconversion) to measure the optical transmittance of an object. The photons of each beam obey a random Poisson process, but are synchronized in time. One beam is used to probe the object while the other is used as a reference providing information …

Combining Wavelets And Hotelling Transforms In Image Query, Sol Neeman Ph.D.

Engineering Studies Faculty Publications and Creative Works

In the "content based" image query, also referred to as "query by example," "similarity retrieval" or "sketch retrieval," the query image is provided by the user either as a sketch of the object, as the output of a scanner or a video camera. Some of the difficulties associated with content based image query are described in [1], e.g. significant difference between the "query image" and the "target image," artifacts and poor resolution of the query image make a straightforward comparison of images using L1 and l2 metrics not effective.

In [2] a new strategy is suggested based on wavelet decomposition …

Effects Of Parasitic Elements On Oscillation Frequency Of Ota-C Sinusoidal Oscillators, Ari̇f Nacaroğlu, Ergun Erçelebi̇

Turkish Journal of Electrical Engineering and Computer Sciences

An oscillator circuit which incorporates Operational Transconductance Amplifiers is presented. The circuit is designed using three OTAs and two grounded capacitors. The frequency of oscillation is tunable over a wide frequency range. The effects of the parasitic elements on the oscillation frequency and the oscillation condition are studied. The theoretical results are compared with the experimental results for a practical oscillator circuit.

On The Global Stabilization Of Nonlinear Systems Via Switching Manifolds, Stephen P. Banks, Meti̇n U. Salamci, M. Kemal Özgören

Turkish Journal of Electrical Engineering and Computer Sciences

The global stabilization of nonlinear systems is investigated by using switching surfaces. The nonlinear system is forced to a lower order switching manifold, which is designed to be stable by construction. Thus, the stability of the reduced-order system is guaranteed and parameter selection for the switching surface is avoided. The method is extended to a class of uncertain nonlinear systems and exemplified with some fictitious dynamic models.

Differentiating Type Of Muscle Movement Via Ar Modeling And Neural Network Classification, Beki̇r Karlik

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this study is to classify electromyogram (EMG) signals for controlling multifunction proshetic devices. An artificial neural network (ANN) implementation was used for this purpose. Autoregressive (AR) parameters of $a_1, a_2, a_3, a_4$ and their signal power obtained from different arm muscle motions were applied to the input of ANN, which is a multilayer perceptron. At the output layer, for 5000 iterations, six movements were distinguished at a high accuracy of 97.6%.

A Simple Formula Obtained Using Tabu Search Algorithm For The Radiation Efficiency Of A Resonant Rectangular Microstrip Antenna, Dervi̇ş Karaboğa, Keri̇m Güney

Turkish Journal of Electrical Engineering and Computer Sciences

A new simple formula for the radiation efficiency of a resonant rectangular microstrip patch antenna is presented. The formula is obtained by using a tabu search algorithm, which is a quite new optimization technique based on the principles of intelligent problem solving. The formula is valid for substrates with relative permittivities between 1 and 12.8 and for the complete range of thicknesses normally used. The results obtained by using this new simple formula are in conformity with those reported elsewhere. The formula can also be used in the calculation of the radiation efficiency of dipoles.

Exclusive Disjunctions In Indefinite And Maybe Information In Relational Databases, Taflan İ. Gündem

Turkish Journal of Electrical Engineering and Computer Sciences

Incorporating indefinite information into databases has been studied extensively. In this paper, we propose a structure called an E-table to represent maybe information and inclusive and exclusive disjunctions. We define the type of redundancies in E-tables and show how to eliminate them. Also we present an extended relational algebra to operate on E-tables. In this paper we expand the concepts and operations defined by Lin and Sunderraman [1] in order to accommodate exclusive disjunctions in relational databases.