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Electrical and Computer Engineering Commons

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2002

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Articles 391 - 401 of 401

Full-Text Articles in Electrical and Computer Engineering

Node Splitting Algorithms In Tree-Structured High-Dimensional Indexes For Similarity Search, Yongjian Fu, Jui Che Teng, S. R. Subramanya Jan 2002

Node Splitting Algorithms In Tree-Structured High-Dimensional Indexes For Similarity Search, Yongjian Fu, Jui Che Teng, S. R. Subramanya

Computer Science Faculty Research & Creative Works

Content-based searches and retrievals in multimedia and image databases use high-dimensional indexing structures for organizing the features of the objects. Most of those index structures are tree-structured whose nodes have a limit on the number of entries describing the subtrees rooted at those nodes. When index trees are built by repeated insertion of entries, nodes need to be split and the tree balanced accordingly. Node-splitting algorithms eventually determine the final structure of the tree which will have a profound effect on the search performance. This paper presents a comparative study of several node splitting algorithms for a typical high-dimensional indexing …


Efficient Algorithms For Creation Of Linearly-Independent Decision Diagrams And Their Mapping To Regular Layouts, Marek Perkowski, Bogdan Jaroslaw Falkowski, Malgorzata Chrzanowska-Jeske, Rolf Dreschler Jan 2002

Efficient Algorithms For Creation Of Linearly-Independent Decision Diagrams And Their Mapping To Regular Layouts, Marek Perkowski, Bogdan Jaroslaw Falkowski, Malgorzata Chrzanowska-Jeske, Rolf Dreschler

Electrical and Computer Engineering Faculty Publications and Presentations

A new kind of a decision diagrams are presented: its nodes correspond to all types of nonsingular expansions for groups of input variables, in particular pairs. The diagrams are called the Linearly Independent (LI) Decision Diagrams (LI DDs). There are 840 nonsigular expansions for a pair of variables, thus 840 different types of nodes in the tree. Therefore, the number of nodes in such (exact) diagrams is usually much smaller than the number of nodes in the well-known Kronecker diagrams (which have only single-variable Shannon, Positive Davio, and Negative Davio expansions in nodes). It is usually much smaller than 1/3 …


Term Trees In Application To An Effective And Efficient Atpg For And–Exor And And–Or Circuits, Lech Jozwiak, Aleksander Ślusarczyk, Marek Perkowski Jan 2002

Term Trees In Application To An Effective And Efficient Atpg For And–Exor And And–Or Circuits, Lech Jozwiak, Aleksander Ślusarczyk, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

A compact data representation, in which the typically required operations are performed rapidly, and effective and efficient algorithms that work on these representations are the essential elements of a successful CAD tool. The objective of this paper is to present a new data representation—term trees (TTs)—and to discuss its application for an effective and efficient structural automatic test-pattern generation (ATPG). Term trees are decision diagrams similar to BDDs that are particularly suitable for structure representation of AND–OR and AND–EXOR circuits. In the paper, a flexible algorithm for minimum term-tree construction is discussed and an effective and efficient algorithm for ATPG …


Multiple-Valued Quantum Logic Synthesis, Marek Perkowski, Anas Al-Rabadi, Pawel Kerttopf Jan 2002

Multiple-Valued Quantum Logic Synthesis, Marek Perkowski, Anas Al-Rabadi, Pawel Kerttopf

Electrical and Computer Engineering Faculty Publications and Presentations

This paper asks the question: is logic synthesis for quantum computers a practical research subject?

We would like to assume that any two quantum wires can interact, but we are limited by the realization constraints. Structure of atomic bonds in the molecule determines neighborhoods in the circuit. This is similar to restricted routing in FPGA layout - link between logic and layout synthesis known from CMOS design now appears in quantum. Below we are interested only in the so-called “permutation circuits” - their unitary quantum matrices are permutation matrices.


Generalized Inclusive Forms — New Canonical Reed-Muller Forms Including Minimum Esops, Marek Perkowski, Alan Mishchenko, Malgorzata Chzanowka-Jeske Jan 2002

Generalized Inclusive Forms — New Canonical Reed-Muller Forms Including Minimum Esops, Marek Perkowski, Alan Mishchenko, Malgorzata Chzanowka-Jeske

Electrical and Computer Engineering Faculty Publications and Presentations

Reed-Muller (AND/EXOR) expansions play an important role in logic synthesis and circuit design by producing economical and highly-testable implementations of Boolean functions [3–6]. The range of Reed-Muller expansions include canonical forms, i.e. expansions that create unique representations of a Boolean function. Several large families of canonical forms: fixed polarity Reed-Muller forms (FPRMs), generalized Reed-Muller forms (GRMs), Kronecker forms (KROs), and pseudo- Kronecker forms (PKROs), referred to as the Green/Sasao hierarchy, have been described [7–9]. (See Fig. 1 for a settheoretic relationship between these families.)


Three-Dimensional Micromachined On-Chip Inductors For High Frequency Applications, Nimit Chomnawang Jan 2002

Three-Dimensional Micromachined On-Chip Inductors For High Frequency Applications, Nimit Chomnawang

LSU Doctoral Dissertations

Demands for wireless communication are ever-escalating for consumer and military communication applications. The requirements of portability, more functionality and lower cost have been driving forces toward smaller, more sophisticated and flexible wireless devices with lower power consumption. To meet these requirements, monolithically integrated passive inductors with high Q-factors and high self-resonant frequencies are desirable. Q-factor and self-resonant frequency of an inductor are significantly degraded at high frequencies due to conductor ohmic loss, magnetically induced eddy current in the conductive substrate, and lower self-resonant frequency from capacitance between conductive substrate and conductors.
In this dissertation, novel three-dimensional arch-like solenoid and dome-shaped …


Nitriding Of Titanium By Inductively Coupled Plasma, Abdul Hakim Hashim Jan 2002

Nitriding Of Titanium By Inductively Coupled Plasma, Abdul Hakim Hashim

Student Works (2000-2009)

A RF planar coil inductively coupled plasma syslem (ICP) is used in this project to nitride a commercially pure titanium substrate. The system is powered by a 600 W, 13.56 MHz, 50 Ω RF generator. The impedance matching is achieved by using an air­-core step-down transformer and a tunable vacuum capacitor. The electrical discharge characteristics of argon and argon-nitrogen admixture plasmas are investigated. Coil current, ion density and RF power transferred in the plasma at different pressure are studied. Nitriding of titanium using the system is found to be able to produce θ-TiN, ε-Ti2N and α-Ti(N) layers, as confirmed by …


Atomic Hydrogen Cleaning Of Inp(100): Electron Yield And Surface Morphology Of Negative Electron Affinity Activated Surfaces, M. A. Hafez, H. E. Elsayed-Ali Jan 2002

Atomic Hydrogen Cleaning Of Inp(100): Electron Yield And Surface Morphology Of Negative Electron Affinity Activated Surfaces, M. A. Hafez, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

Atomic hydrogen cleaning of the InP(100) surface has been investigated using quantitative reflection high-energy electron diffraction. The quantum efficiency of the surface when activated to negative electron affinity was correlated with surface morphology. The electron diffraction patterns showed that hydrogen cleaning is effective in removing surface contaminants, leaving a clean, ordered, and (2×4)-reconstructed surface. After activation to negative electron affinity, a quantum efficiency of ∼6% was produced in response to photoactivation at 632 nm. Secondary electron emission from the hydrogen-cleaned InP(100)-(2×4) surface was measured and correlated to the quantum efficiency. The morphology of the vicinal InP(100) surface was investigated using …


Electron Pulse Broadening Due To Space Charge Effects In A Photoelectron Gun For Electron Diffraction And Streak Camera Systems, Bao-Liang Qian, Hani E. Elsayed-Ali Jan 2002

Electron Pulse Broadening Due To Space Charge Effects In A Photoelectron Gun For Electron Diffraction And Streak Camera Systems, Bao-Liang Qian, Hani E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

The electron pulse broadening and energy spread, caused by space charge effects, in a photoelectron gun are studied analytically using a fluid model. The model is applicable in both the photocathode-to-mesh region and the postanode electron drift region. It is found that space charge effects in the photocathode-to-mesh region are generally unimportant even for subpicosecond pulses. However, because of the long drift distance, electron pulse broadening due to space charge effects in the drift region is usually significant and could be much larger than the initial electron pulse duration for a subpicosecond electron pulse. Space charge effects can also lead …


Acceleration Element For Femtosecond Electron Pulse Compression, Bao-Liang Qian, Hani E. Elsayed-Ali Jan 2002

Acceleration Element For Femtosecond Electron Pulse Compression, Bao-Liang Qian, Hani E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

An acceleration element is proposed for compressing the electron pulse duration in a femtosecond photoelectron gun. The element is a compact metal cavity with curved-shaped walls. An external voltage is applied to the cavity where a special electric field forms in such a way that the slow electrons in the electron pulse front are accelerated more than the fast electrons, and consequently the electron pulse duration will be compressed. The distribution of the electric field inside the acceleration cavity is analyzed for the geometry of the cavity. The electron dynamics in this acceleration cavity is also investigated numerically. Numerical results …


121.6 Nm Radiation Source For Advanced Lithography, Jianxun Yan, Ashraf El-Dakrouri, Mounir Laroussi, Mool C. Gupta Jan 2002

121.6 Nm Radiation Source For Advanced Lithography, Jianxun Yan, Ashraf El-Dakrouri, Mounir Laroussi, Mool C. Gupta

Electrical & Computer Engineering Faculty Publications

A vacuum ultraviolet (VUV) light source based on a high-pressure cylindrical dielectric barrier discharge (DBD) has been developed. Intense and spectrally clean Lyman-α line at 121.6 nm was obtained by operating a DBD discharge in neon with a small admixture of hydrogen. The spectrum, optical power, stability, and efficiency of the source were measured. The influence of the gas mixture and total gas pressure on the VUV intensity has been investigated. Maximum optical power of 3.2 W and spectral width 0.03 nm was achieved. Power stability of 2% for 100 h of operation has also been obtained. The newly developed …