Physical Sciences and Mathematics Commons^™

Crystal Growth Of Complex Intermetallics In Search For Heavy Electron Systems, Brenton L. Drake

LSU Doctoral Dissertations

The structural solution and physical property characterization of several Ln-T-Al/Ga and Ln-T-Al-Si contain phases, which include Ln(Cu,Al)12 (Ln = Y, Ce, Pr, Sm, and Yb), Ln(Ag,Al,Si)2 (Ln = Ce and Gd), LnCu2(Al,Si)5 (Ln = La and Ce), Ln(Cu,Al,Ga)13-x (Ln = La, Ce, Pr, and Eu), α and β LnNiGa4 (α Ln = Y and Gd – Yb; β Ln = (Tb – Er)), and Ln4FeGa12 (Ln = Tb – Er) will be presented in this work with an emphasis on crystal growth. The systems cover a large breadth of phase space and serve to illustrate the new and rich chemistry …

Evolution Of Structural And Physical Properties Of Transition Metal Oxide Sr₃(Ru₁₋Xmnx)₂O₇ (0 <̲ X >̲ 0.7) With Mn Concentration, Biao Hu

LSU Doctoral Dissertations

Correlated Electron Materials (CEMs) have attracted the attention of the materials community because the strong coupling between charge, lattice, orbital, and spin degrees of freedom produces exotic phenomena. Transition metal oxide series Srn+1RunO3n+1 (n = 1 to ∞) is a prototype of CEMs. The n = 2 member of this family Sr3Ru2O7 is the subject of this dissertation. It has a paramagnetic (PM) metallic ground state, which can be driven into an antiferromagnetic (AFM) insulator with a partial substitution of Ru by Mn. The focus of this research is to understand the role of chemical doping as the driving force …

Separating Ne From Some Nonuniform Nondeterministic Complexity Classes, Bin Fu, Ansheng Li, Liyu Zhang

Computer Science Faculty Publications and Presentations

We investigate the question whether NE can be separated from the reduction closures of tally sets, sparse sets and NP. We show that (1) NE 6 ⊆ RNP no(1) −T (TALLY); (2)NE 6 ⊆ RSN m (SPARSE); and (3) NE 6 ⊆ PNP nk −T /nk for all k ≥ 1. Result (3) extends a previous result by Mocas to nonuniform reductions. We also investigate how different an NE-hard set is from an NP-set. We show that for any NP subset A of a many-one-hard set H for NE, there exists another NP subset A′ of H such that A′ …

Effecting Data Quality Through Data Governance: A Case Study In The Financial Services Industry, Patrick Egan

Regis University Student Publications (comprehensive collection)

One of the most significant challenges faced by senior management today is implementing a data governance program to ensure that data is an asset to an organization's mission. New legislation aligned with continual regulatory oversight, increasing data volume growth, and the desire to improve data quality for decision making are driving forces behind data governance initiatives. Data governance involves reshaping existing processes and the way people view data along with the information technology required to create a consistent, secure and defined processes for handling the quality of an organization's data. In examining attempts to move towards making data an asset …

Book Review: Exploring Mars: Chronicles From A Decade Of Discovery, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Exploring Mars : Chronicles from a Decade of Discovery by Scott Hubbard. Arizona, 2011 194p, 9780816521111 $45.00, 9780816528967 $17.95.

Commuting Smoothed Projectors In Weighted Norms With An Application To Axisymmetric Maxwell Equations, Jay Gopalakrishnan, Minah Oh

Mathematics and Statistics Faculty Publications and Presentations

We construct finite element projectors that can be applied to functions with low regularity. These projectors are continuous in a weighted norm arising naturally when modeling devices with axial symmetry. They have important commuting diagram properties needed for finite element analysis. As an application, we use the projectors to prove quasioptimal convergence for the edge finite element approximation of the axisymmetric time-harmonic Maxwell equations on nonsmooth domains. Supplementary numerical investigations on convergence deterioration at high wavenumbers and near Maxwell eigenvalues and are also reported.

Parametric Estimation In Competing Risks And Multi-State Models, Yushun Lin

Theses and Dissertations--Statistics

The typical research of Alzheimer's disease includes a series of cognitive states. Multi-state models are often used to describe the history of disease evolvement. Competing risks models are a sub-category of multi-state models with one starting state and several absorbing states.

Analyses for competing risks data in medical papers frequently assume independent risks and evaluate covariate effects on these events by modeling distinct proportional hazards regression models for each event. Jeong and Fine (2007) proposed a parametric proportional sub-distribution hazard (SH) model for cumulative incidence functions (CIF) without assumptions about the dependence among the risks. We modified their model to …

Stochastic Dynamics Of Gene Transcription, Yan Xie

Theses and Dissertations--Statistics

Gene transcription in individual living cells is inevitably a stochastic and dynamic process. Little is known about how cells and organisms learn to balance the fidelity of transcriptional control and the stochasticity of transcription dynamics. In an effort to elucidate the contribution of environmental signals to this intricate balance, a Three State Model was recently proposed, and the transcription system was assumed to transit among three different functional states randomly.

In this work, we employ this model to demonstrate how the stochastic dynamics of gene transcription can be characterized by the three transition parameters. We compute the probability distribution of …

A Topological Approach To Molecular Chirality, Erica Flapan

Pomona Faculty Publications and Research

Topology is the study of deformations of geometric figures. Chemistry is the study of molecular structures. At first glance these fields seem to have nothing in common. But let’s take a closer look to see how these fields come together in the study of molecular symmetries.

Review: Nearly Invariant Subspaces For Backwards Shifts On Vector-Valued Hardy Spaces, Stephan Ramon Garcia

Pomona Faculty Publications and Research

No abstract provided.

Quotient Sets And Diophantine Equations, Stephan Ramon Garcia, Vincent Selhorst-Jones '09, Daniel E. Poore '11, Noah Simon '08

Pomona Faculty Publications and Research

Quotient sets U / U = {u / u¹: u, u¹ ϵ U} have been considered several times before in the MONTHLY. We consider more general quotient sets U / V and we apply our results to certain simultaneous Diophantine equations with side constraints.

Spatial Isomorphisms Of Algebras Of Truncated Toeplitz Operators, Stephan Ramon Garcia, William T. Ross, Warren R. Wogen

Pomona Faculty Publications and Research

We examine when two maximal abelian algebras in the truncated Toeplitz operators are spatially isomorphic. This builds upon recent work of N. Sedlock, who obtained a complete description of the maximal algebras of truncated Toeplitz operators.

Analysis Of Hdg Methods For Stokes Flow, Bernardo Cockburn, Jay Gopalakrishnan, Ngoc Cuong Nguyen, Jaume Peraire, Francisco-Javier Sayas

Mathematics and Statistics Faculty Publications and Presentations

In this paper, we analyze a hybridizable discontinuous Galerkin method for numerically solving the Stokes equations. The method uses polynomials of degree $ k$ for all the components of the approximate solution of the gradient-velocity-pressure formulation. The novelty of the analysis is the use of a new projection tailored to the very structure of the numerical traces of the method. It renders the analysis of the projection of the errors very concise and allows us to see that the projection of the error in the velocity superconverges. As a consequence, we prove that the approximations of the velocity gradient, the …

Topological Symmetry Groups Of K4r+3, Dwayne Chambers '12, Erica Flapan, John D. O'Brien

Pomona Faculty Publications and Research

We present the concept of the topological symmetry group as a way to analyze the symmetries of non-rigid molecules. Then we characterize all of the groups which can occur as the topological symmetry group of an embedding of a complete graph of the form K4r+3^in S³.

Inter-Colony Comparison Of Diving Behavior Of An Arctic Top Predator: Implications For Warming In The Greenland Sea, Nina J. Karnovsky, Zachary W. Brown '07, Jorg Welcker, Ann M.A. Harding, Wojciech Walkusz, André Cavalcanti, Johanna S. Hardin, Alexander Kitaysky, Geir Gabrielsen, David Grémillet

Pomona Faculty Publications and Research

The goal of this study was to assess how diverse oceanographic conditions and prey communities affect the foraging behavior of little auks Alle alle. The Greenland Sea is characterized by 3 distinct water masses: (1) the East Greenland Current (EGC), which carries Arctic waters southward; (2) the Sørkapp Current (SC), which originates in the Arctic Ocean but flows north along the west coast of Spitsbergen; and (3) the West Spitsbergen Current (WSC), which carries warm Atlantic-derived water north. Each of these 3 water masses is characterized by a distinct mesozooplankton community. Little auks breeding adjacent to the EGC have …

Geologic Map Of The Ganiki Planitia Quadrangle (V–14), Venus, Eric B. Grosfils, Sylvan M. Long, Elizabeth M. Venechuk, Debra M. Hurwitz, Joseph W. Richards, Brian Kastl, Dorothy E. Drury, Johanna S. Hardin

Pomona Faculty Publications and Research

Our current research focuses on addressing four specific questions. Has the dominant style of volcanic expression within the quadrangle varied in a systematic fashion over time? Does the tectonic deformation within the quadrangle record significant regional patterns that vary spatially or temporally, and if so what are the scales, orientations and sources of the stress fields driving this deformation? If mantle upwelling and downwelling have played a significant role in the formation of Atla Regio and Atalanta Planitia as has been proposed, does the geology of Ganiki Planitia record evidence of northwest-directed lateral mantle flow connecting the two sites? Finally, …

Unitary Equivalence To A Complex Symmetric Matrix: A Modulus Criterion, Stephan Ramon Garcia, Daniel E. Poore '11, Madeline K. Wyse '11

Pomona Faculty Publications and Research

We develop a procedure for determining whether a square complex matrix is unitarily equivalent to a complex symmetric (i.e., self-transpose) matrix. We compare our approach to several existing methods [1, 19, 20] and present a number of examples.

Classical Kloosterman Sums: Representation Theory, Magic Squares, And Ramanujan Multigraphs, Patrick S. Fleming, Stephan Ramon Garcia, Gizem Karaali

Pomona Faculty Publications and Research

We consider a certain finite group for which Kloosterman sums appear as character values. This leads us to consider a concrete family of commuting hermitian matrices which have Kloosterman sums as eigenvalues. These matrices satisfy a number of “magical” combinatorial properties and they encode various arithmetic properties of Kloosterman sums. These matrices can also be regarded as adjacency matrices for multigraphs which display Ramanujan-like behavior.

Trash Talk: A Case Study Of Waste Analysis At Pomona College, Char Miller, Bowen Close

Pomona Faculty Publications and Research

Purpose: This paper presents the pedagogical initiatives associated with and the practical outcomes of a multi-student independent study that analyzed the campus waste stream and developed real-world solutions in accord with the college’s sustainability commitments and goals.

Design/methodology: The paper reviews the course structure, presents research findings and the individual student-developed solutions, and assesses their ability to reduce the campus’s waste stream.

Findings: Developing a class to audit the campus waste stream offers students an unusual educational opportunity to apply theoretical insights to and test these against a real-world problem; their analyses and projects also has helped …

Effective Size And Expansion Energy Of A Bose-Einstein Condensate In A 3d Non-Cubic Optical Lattice, Shemi S. M. Soliman

Turkish Journal of Physics

This work is devoted to study the temperature dependence of the effective size and expansion energy E_{x,z} of a Bose-Einstein condensate in a 3D non-cubic optical lattice. Correction due to the finite size, interatomic interaction and the deepness of the lattice potential are given simultaneously. The calculated results show that these two parameters increase with the lattice depth or the relative frequency at temperature less than the transition temperature, (T < T_o); yet it has little effect at temperatures higher than the transition temperature (T > T_o). Both the effective size and expansion energy follow a characteristic temperature dependence, i.e. , E \propto(T/T_0)^4 if T < T_0 and , E \propto (T/T_0) if T > T_0. For a 3D non cubic optical potential the effect of …

Differential Geometry Of Moving Surfaces And Its Relation To Solitons, Andrei Ludu

Publications

In this article we present an introduction in the geometrical theory of motion of curves and surfaces in R 3 , and its relations with the nonlinear integrable systems. The working frame is the Cartan’s theory of moving frames together with Cartan connection. The formalism for the motion of curves is constructed in the Serret-Frenet frames as elements of the bundle of adapted frames. The motion of surfaces is investigated in the Gauss-Weingarten frame. We present the relations between types of motions and nonlinear equations and their soliton solutions.

Development Of A Method For Quantifying The Air-Sea Flux Of Volatile Organic Carbon, Emily A. Jayne

Dissertations, Theses, and Masters Projects

No abstract provided.

(Editorial) A Long Term View Of Rare Plant Reintroduction. A Response To Godefroid Et Al. 2011: How Successful Are Plant Reintroductions?, Matthew A. Albrecht, Edward O. Guerrant Jr., Joyce Maschinski, Kathryn Kennedy

Environmental Science and Management Faculty Publications and Presentations

This is an editorial response to Godefroidet al. (2011). How successful are plant species reintroductions? Biological Conservation 144, 672-682.

Kinematical Conformal Cosmology: Fundamental Parameters From Astrophysical Observations, Gabriele U. Varieschi

Physics Faculty Works

No abstract provided.

Complete Graphs Whose Topological Symmetry Groups Are Polyhedral, Eric Flapan, Blake Mellor, Ramin Naimi

Mathematics, Statistics and Data Science Faculty Works

We determine for which m the complete graph K_m has an embedding in S³ whose topological symmetry group is isomorphic to one of the polyhedral groups A₄, A₅ or S₄.

The Chemistry Of Atmosphere-Forest Exchange (Cafe) Model-Part 2: Application To Bearpex-2007 Observations, Nicole C. Bouvier-Brown

Chemistry and Biochemistry Faculty Works

In a companion paper, we introduced the Chemistry of Atmosphere-Forest Exchange (CAFE) model, a vertically-resolved 1-D chemical transport model designed to probe the details of near-surface reactive gas exchange. Here, we apply CAFE to noontime observations from the 2007 Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX-2007). In this work we evaluate the CAFE modeling approach, demonstrate the significance of in-canopy chemistry for forest-atmosphere exchange and identify key shortcomings in the current understanding of intra-canopy processes.

CAFE generally reproduces BEARPEX-2007 observations but requires an enhanced radical recycling mechanism to overcome a factor of 6 underestimate of hydroxyl (OH) concentrations observed …

A Low-Cost Motion Tracking System For Virtual Reality Applications, Abhinav Chadda

Masters Theses

"This thesis provides an insight into the design and development of a highly effective, low-cost motion tracking system comprised of off-the-shelf (OTS) hardware for virtual reality applications. Present-day motion tracking systems usually have a high cost associated with them. A capable yet affordable OTS motion tracking system is a key enabler to make motion controlled virtual reality an accessible and ubiquitous technology.

The motion tracking system developed in this study is used in conjunction with virtual reality software towards simple and natural human-computer interface solutions. It is developed with the budget of $1,000 per system. The cost includes 2 cameras …

Robustness, Weak Stability, And Stability In Distribution Of Adaptive Filteringalgorithms Under Model Mismatch, Ben G. Fitzpatrick, G. Yin, Le Yi Wang

Mathematics, Statistics and Data Science Faculty Works

This work is concerned with robustness, convergence, and stability of adaptive filtering (AF) type algorithms in the presence of model mismatch. The algorithms under consideration are recursive and have inherent multiscale structure. They can be considered as dynamic systems, in which the `state' changes much more slowly than the perturbing noise. Beyond the existing results on adaptive algorithms, model mismatch significantly affects convergence properties of AF algorithms, raising issues of algorithm robustness. Weak convergence and weak stability (i.e., recurrence) under model mismatch are derived. Based on the limiting stochastic differential equations of suitably scaled iterates, stability in distribution is established. …

Finitely 1-Convex F-Rings, Suzanne Larson

Mathematics, Statistics and Data Science Faculty Works

This paper investigates f-rings that can be constructed in a finite number of steps where every step consists of taking the fibre product of two f-rings, both being either a 1-convex f-ring or a fibre product obtained in an earlier step of the construction. These are the f-rings that satisfy the algebraic property that rings of continuous functions possess when the underlying topological space is finitely an F-space (i.e. has a Stone-čech compactification that is a finite union of compact F-spaces). These f-rings are shown to be SV f-rings with bounded inversion and finite rank and, when constructed from semisimple …

Heavy Episodic Drinking On College Campuses: Does Changing The Legal Drinking Age Make A Difference?, Jawaid W. Rasul, Robert G. Rommel, Geoffrey M. Jacquez, Ben G. Fitzpatrick, Azmy S. Ackleh, Neal Simonsen, Richard Scribner

Mathematics, Statistics and Data Science Faculty Works

This article extends the compartmental model previously developed by Scribner et al. in the context of college drinking to a mathematical model of the consequences of lowering the legal drinking age. Method: Using data available from 32 U.S. campuses, the analyses separate underage and legal age drinking groups into an eight-compartment model with different alcohol availability (wetness) for the underage and legal age groups. The model evaluates the likelihood that underage students will incorrectly perceive normative drinking levels to be higher than they actually are (i.e., misperception) and adjust their drinking accordingly by varying the interaction between underage students in …