Digital Commons Network^™

Exact Filtered Back Projection (Fbp) Algorithm For Spiral Computer Tomography [Us], Alexander Katsevich

UCF Patents

Reconstructing images of objects spirally scanned with two-dimensional detectors with a novel algorithm. The image reconstruction process is proven to create an exact image of the object under the ideal circumstances. The algorithm has an FBP (Filtered Back Projection) structure and works very efficiently. The algorithm uses less computer power and combines the benefits of Exact Algorithms and Approximate algorithms.

Method For Monitoring A Characteristic Of A Mixture Comprising Particles Suspended In A Liquid., Aristide Dogariu, Gabriel Popescu

UCF Patents

The specification describes a method for monitoring a characteristic of a mixture of particles suspended in a liquid medium by generating a first interference signal by combining first and second radiation beams after the first beam traverses a reference path and the second beam traverses a path extending into the mixture, allowing the particles in the mixture to partially settle, then generating a second interference signal by the same technique as used for the first. The second interference signal is then compared to the first interference signal to determine a change in, e.g., the particle density.

University Of Central Florida Commencement, May 2 & 3, 2003, University Of Central Florida

Commencement Programs

No abstract provided.

University Of Central Florida Graduate Catalog, 2003 - 2004, University Of Central Florida

UCF Catalogs

No abstract provided.

University Of Central Florida Undergraduate Catalog, 2003 - 2004, University Of Central Florida

UCF Catalogs

No abstract provided.

Central Florida Future, Vol. 35 No. 60, April 21, 2003

Central Florida Future

Professor's research may predict traffic accidents on I-4; The Code Wars: Professor Peter Hilton's decoding methods during World War II laid foundation for technology in today's war; Former general commands attention of UCF students.

Sandspur, Vol 109, No 20, April 04, 2003, Rollins College

The Rollins Sandspur

Rollins College student newspaper, written by the students and published at Rollins College. The Sandspur started as a literary journal.

The Learning Marketspace, April 2003, Bob Heterick, Carol Twigg

The Learning MarketSpace (4/03 - 4/14)

No abstract provided.

Sandspur, Vol 109, No 18, March 21, 2003, Rollins College

The Rollins Sandspur

Rollins College student newspaper, written by the students and published at Rollins College. The Sandspur started as a literary journal.

Optical System For Characterizing Particles In A Colloidal Suspension Using Interferometry., Aristide Dogariu, Gabriel Popescu

UCF Patents

An optical system for monitoring a colloidal suspension includes a chamber positioned to receive a sample of the suspension while the suspension is circulating in a mechanical system. An interferometer is positioned to generate interference patterns developed by a combination of a reference radiation signal with a sample radiation signal indicative of a characteristic in the suspension.

Central Florida Future, Vol. 35 No. 36, January 21, 2003

Central Florida Future

U. of Alabama tempts Hitt with university presidency; Point guard felony charges.

Central Florida Future, Vol. 35 No. 33, January 9, 2003

Central Florida Future

Universities vie for politicians; Gay rights laws take shape in city Will UCF be next?; Web site aims to curtail student drinking.

On Sport And Society 01-07-2003, Richard C. Crepeau

On Sport and Society

Cub fans are a unique species. Attachment to losing is taken to a level of religious fanaticism by the Cub faithful. Of course the charm of the Cubs is not simply that they lose, but that they are lovable losers. This is what inspires undying devotion in their fans. Indeed if the Cubs were to do the improbable, nay the impossible, and win a World Series, Cub fans would risk losing the essence of their Cubness.

Multiple Damage Detection In Structures Using A Coupled Modal Analysis And Wavelet Transform Technique, Nasser S. Bajabaa

Retrospective Theses and Dissertations

A new technique that couples modal analysis and wavelet transforms for detection of multiple damage in structures is introduced. Structural damage may cause local changes in one or more of the following parameters; stiffness, mass and damping that affect the dynamic behavior of the structure. For example, a crack reduces the stiffness of the structure in a localized sense, and thus reducing its natural frequency, and causes changes in both modal damping and mode shapes. In this research, two different structures have been analyzed: beams and plates. First, uniform beams with a single damage (notch) of different sizes at different …

Video Categorization Using Semantics And Semiotics, Zeeshan Rasheed

Retrospective Theses and Dissertations

There is a great need to automatically segment, categorize, and annotate video data, and to develop efficient tools for browsing and searching. We believe that the categorization of videos can be achieved by exploring the concepts and meanings of the videos. This task requires bridging the gap between low-level content and high-level concepts (or semantics). Once a relationship is established between the low-level computable features of the video and its semantics, the user would be able to navigate through videos through the use of concepts and ideas (for example, a user could extract only those scenes in an action film …

A Study Of High School Students' Perceptions Of Their Safety In School, Christina L. Testani Cafiero

Retrospective Theses and Dissertations

This study was designed to investigate the factors that contributed to high school students' sense of security at school, and what these students perceived as measures that if put in place, would increase their feelings of security. The focus was the relationship between students' perceptions of safety at school and their own opinions of school and their experiences at school.

The study was conducted in the School District of Osceola County, Florida. The population of this study was comprised of all students enrolled in the public high schools in the School District of Osceola County. The sample for the study …

University Of Central Florida Ir 3-Year Fact Book - Ay 2000-2001 Through Ay 2002-2003, University Of Central Florida

Historical Fact Book and Enrollment

Historical fact book and enrollment data for the University of Central Florida.

Electron-Inertia Effects On Driven Magnetic Field Reconnection, N. Al-Salti, B. K. Shivamoggi

Faculty Bibliography 2000s

Electron-inertia effects on the magnetic field reconnection induced by perturbing the boundaries of a slab of plasma with a magnetic neutral surface inside are considered. Energetics of the tearing mode dynamics with electron inertia which controls the linearized collisionless magnetohydrodynamics (MHD) are considered with a view to clarify the role of the plasma pressure in this process. Cases with the boundaries perturbed at rates slow or fast compared with the hydromagnetic evolution rate are considered separately. When the boundaries are perturbed at a rate slow compared with the hydromagnetic evolution rate and fast compared with the resistive diffusion rate, the …

Coherence Properties Near Interfaces Of Random Media, A. Apostol, A. Dogariu

Faculty Bibliography 2000s

The spatial coherence theory of optical fields radiated by statistically homogeneous, infinite, planar sources does not account for detailed surface characteristics. However, coherence properties change with the angular distribution of the intensity radiated from such a source, which, in turn, depends on the physical properties of the sample. We show that second-order correlations of the optical field measured at several wavelengths away from the surface of a highly inhomogeneous medium relate to the statistical characteristics of the interface.

Transforming Education, Transforming Ourselves: Contributions And Lessons Learned, Karen L. Biraimah

Faculty Bibliography 2000s

No abstract provided.

Financial Factors And Investment In Belgium, France, Germany, And The United Kingdom: A Comparison Using Company Panel Data, Stephen Bond, Julie Ann Elston, Jacques Mairesse, Benoît Mulkay

Faculty Bibliography 2000s

We construct company panel data sets for manufacturing firms in Belgium, France, Germany, and the United Kingdom, covering the period 1978-1989. These data sets are used to estimate empirical investment equations, and to investigate the role played by financial factors in each country. A robust finding is that cash flow and profits terms appear to be both statistically and quantitatively more significant in the United Kingdom than in the three continental European countries. This is consistent with the suggestion that financial constraints on investment may be relatively severe in the more market-oriented U.K. financial system.

Incoherent White Light Solitons In Logarithmically Saturable Noninstantaneous Nonlinear Media, H. Buljan, A. Šiber, M. Soljacic, T. Schwartz, M. Segev, Demetrios N. Christodoulides

Faculty Bibliography 2000s

We analytically demonstrate the existence of white light solitons in logarithmically saturable noninstantaneous nonlinear media. This incoherent soliton has elliptic Gaussian intensity profile, and elliptic Gaussian spatial correlation statistics. The existence curve of the soliton connects the strength of the nonlinearity, the spatial correlation distance as a function of frequency, and the characteristic width of the soliton. For this soliton to exist, the spatial correlation distance must be smaller for larger temporal frequency constituents of the beam.

Observation Of Multiple Soliton Generation Mediated By Amplification Of Asymmetries, Silvia Carrasco, Sergey Polyakov, Hongki Kim, Ladislav Jankovic, George I. Stegeman, Juan P. Torres, Lluis Torner, Mordechai Katz, David Eger

Faculty Bibliography 2000s

We report the experimental observation of the formation of multiple optical quadratic solitons in a process mediated by the amplification of minute asymmetries in the diffraction properties of the input light. Experiments were conducted in phase-matched second-harmonic generation in a bulk crystal of periodically poled potassium titanyl phosphate pumped at 1064 nm. The different mechanisms that influence the process were investigated numerically, and the pulsed nature of the pump light was found to play a key role in the observed light distributions.

Discrete Ginzburg-Landau Solitons, Nikolaos K. Efremidis, Demetrios N. Christodoulides

Faculty Bibliography 2000s

We demonstrate that discrete solitons are possible in Ginzburg-Landau lattices. As a result of discreteness, we find that this system exhibits a host of features that have no counterpart whatsoever in either the continuous limit or in other conservative discrete models.

Lattice Solitons In Bose-Einstein Condensates, Nikolaos K. Efremidis, Demetrios N. Christodoulides

Faculty Bibliography 2000s

We systematically study the properties of lattice solitons in Bose-Einstein condensates with either attractive or repulsive atom interactions. This is done, by exactly solving the mean-field Gross-Pitaevskii equation in the presence of a periodic potential. We find new families of lattice soliton solutions that are characterized by the position of the energy eigenvalue within the associated band structure. These include lattice solitons in condensates with either attractive or repulsive atom interactions that exist in finite or semi-infinite gaps, as well as nonlinear modes that exhibit atomic population cutoffs.

A General Paradigm To Model Reaction-Based Biogeochemical Processes In Batch Systems, Yilin Fang, Gour-Tsyh Yeh, William D. Burgos

Faculty Bibliography 2000s

[1] This paper presents the development and illustration of a numerical model of reaction-based geochemical and biochemical processes with mixed equilibrium and kinetic reactions. The objective is to provide a general paradigm for modeling reactive chemicals in batch systems, with expectations that it is applicable to reactive chemical transport problems. The unique aspects of the paradigm are to simultaneously (1) facilitate the segregation (isolation) of linearly independent kinetic reactions and thus enable the formulation and parameterization of individual rates one reaction by one reaction when linearly dependent kinetic reactions are absent, (2) enable the inclusion of virtually any type of …

Simulations Of Liquid-Crystal Fabry-Perot Etalons By An Improved 4x4 Matrix Method, Yuhua Huang, Thomas X. Wu, Shin-Tson Wu

Faculty Bibliography 2000s

The optical performances of a liquid crystal (LC) Fabry-Perot (FP) etalon in various configurations were simulated by a faster 4 x 4 matrix method. Results show that the FP with a 90degrees twisted nematic LC is polarization. insensitive if the applied voltage exceeds similar to3X of the Freedericksz transition threshold. This method can well depict the transmission spectra of the FP cavity and, therefore, is useful for optimizing the FP tunable filters for telecommunications.

Discrete Vector Solitons In Two-Dimensional Nonlinear Waveguide Arrays: Solutions, Stability, And Dynamics, J. Hudock, P. G. Kevrekidis, B. A. Malomed, Demetrios N. Christodoulides

Faculty Bibliography 2000s

We identify and investigate bimodal (vector) solitons in models of square-lattice arrays of nonlinear optical waveguides. These vector self-localized states are, in fact, self-induced channels in a nonlinear photonic-crystal matrix. Such two-dimensional discrete vector solitons are possible in waveguide arrays in which each element carries two light beams that are either orthogonally polarized or have different carrier wavelengths. Estimates of the physical parameters necessary to support such soliton solutions in waveguide arrays are given. Using Newton relaxation methods, we obtain stationary vector-soliton solutions, and examine their stability through the computation of linearized eigenvalues for small perturbations. Our results may also …

Generalized Jordan Derivations On Prime Rings And Standard Operator Algebras, Wu Jing, Shijie Lu

Faculty Bibliography 2000s

In this paper we initiate the study of generalized Jordan derivations and generalized Jordan triple derivations on prime rings and standard operator algebras.

Minimum Lagrange Multiplier Unit Root Test With Two Structural Breaks, Junsoo Lee, Mark C. Strazicich

Faculty Bibliography 2000s

The endogenous two-break unit root test of Lumsdaine and Papell is derived assuming no structural breaks under the null. Thus, rejection of the null does not necessarily imply rejection of a unit root per se, but may imply rejection of a unit root without break. Similarly, the alternative does not necessarily imply trend stationarity with breaks, but may indicate a unit root with breaks. In this paper, we propose an endogenous two-break Lagrange multiplier unit root test that allows for breaks under both the null and alternative hypotheses. As a result, rejection of the null unambiguously implies trend stationarity.