Physical Sciences and Mathematics Commons^™

Cross-Talk: A Shared Parameter Space For Gesturally Extended Human/Machine Improvisation, William Brent, Adam James Wilson

Publications and Research

This paper describes Cross-talk, a piece of music and performance system for two instruments augmented with infrared motion-tracking capability, and an artificial software improviser. Cross-talk was commissioned by the Ammerman Center for Arts and Technology at Connecticut College, for the 13th Biennial Symposium on Arts and Technology. The work is part of an ongoing collaboration focused on developing integrated hardware and software performance systems to extend the timbral and expressive capabilities of traditional musical instruments and to generate musical structure in response to information retrieved from human performers in real-time. Artistic motivations and prior related work are presented here, along …

Jones Seeks To Engage Students In Chemistry, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Hildebrandt Teaches Lessons About Tornadoes, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Jennings Studies Environmental Pollutants, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Ledzewicz Applies Math To Health Sciences, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Minchin Studies, Teaches Conservation Issues, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Homogeneous Besov Spaces On Stratified Lie Groups And Their Wavelet Characterization, Hartmut Fuhr, Azita Mayeli

Publications and Research

We establish wavelet characterizations of homogeneous Besov spaces on stratified Lie groups, bothin terms of continuous and discrete wavelet systems. We first introduce a notion of homogeneous Besov space ̇Bsp,qin terms of a Littlewood-Paley-type decomposition, in analogy to the well-known characterization of the Euclidean case. Such decompositions can be defined via the spectral measure of a suitably chosen sub-Laplacian. We prove that the scale of Besov spaces is independent of the precise choice of Littlewood-Paley decomposition. In particular, different sub-Laplacians yield the same Besov spaces. We then turn to wavelet characterizations, first via continuous wavelet transforms which can be viewed …

Parallel Trie-Based Frequent Itemset Mining On Graphics Processors, Jay Junjie Yao

Dissertations and Theses

No abstract provided.

Context Awareness And Discovery For Helping The Blind, Martin Goldberg

Dissertations and Theses

No abstract provided.

The Minimum Of The Maximum Rectilinear Crossing Numbers Of Small Cubic Graphs, Matthew Alpert, Jens-P. Bode, Elie Feder, Heiko Harborth

Publications and Research

Here we consider the minimum of the maximum rectilin­ear crossing numbers for all d-regular graphs of order n. The case of connected graphs only is investigated also. For d = 3 exact values are determined for n are less than or equal to 12 and some estimations are given in general.

Quantum Tunneling Of The Magnetic Moment In A Free Nanoparticle, Michael F. O'Keeffe, Eugene M. Chudnovsky, Dmitry A. Garanin

Publications and Research

We study tunneling of the magnetic moment in a particle that has full rotational freedom. Exact energy levels are obtained and the ground-state magnetic moment is computed for a symmetric rotor. The effect of the mechanical freedom on spin tunneling manifests itself in a strong dependence of the magnetic moment on the moments of inertia of the rotor. Energy of the particle exhibits quantum phase transitions between states with different values of the magnetic moment. Particles of various shapes are investigated and quantum phase diagram is obtained.

Effects Of Arsenic And Uvb Radiation On Induction Of Cyclin D1 In Human Keratinocytes., Julian Gonzalez

Dissertations and Theses

Arsenic and Ultraviolet radiation B (UVB) are environmental toxins that have been linked to various epithelial cancers. Arsenic metabolism in humans leads to its collection in the skin, where it encounters and can act with known carcinogen UVB. Epidemiological evidence of the two toxins demonstrates their potential to affect signaling pathways, with various consequences. Here we employ an in vitro model system using Normal Human Epidermal Keratinocytes (NHEK) to identify the effect of arsenic and UVB on humans and whether they work synergistically. We find that although both cause induction of cyclin D1, culturing cells with both co-mutagens does not …

Multimedia Content-Based Indexing And Recognition In Digital Libraries, Steven Medina

Dissertations and Theses

"Recognition of digital media is more prevalent in today’s computer culture than ever before. The advent of low cost storage has created a seemingly infinite amount of metadata on the internet, as well as on local machines throughout the world. It is more important than ever to have the capability of quickly and accurately filtering this metadata to find a desired result. Data can be searched using various criteria. For example, text data is searched by analyzing the contents of the text itself. One might execute a search using a method as simple as looking for the ASCII file name, …

Geometric Graph Theory And Wireless Sensor Networks, Deniz Sarioz

Dissertations, Theses, and Capstone Projects

In this work, we apply geometric and combinatorial methods to explore a variety of problems motivated by wireless sensor networks. Imagine sensors capable of communicating along straight lines except through obstacles like buildings or barriers, such that the communication network topology of the sensors is their visibility graph. Using a standard distributed algorithm, the sensors can build common knowledge of their network topology.

We first study the following inverse visibility problem: What positions of sensors and obstacles define the computed visibility graph, with fewest obstacles? This is the problem of finding a minimum obstacle representation of a graph. This minimum …

Conservation Of Angular Momentum In A Flux Qubit, Eugene M. Chudnovsky, Dmitry A. Garanin, Michael F. O'Keeffe

Publications and Research

Oscillations of superconducting current between clockwis e and counterclockwise directions in a flux qubit do not conserve the angular momentum of the qubit. T o compensate for this effect the solid containing the qubit must oscillate in unison with the current. This requires entanglement of quantum states of the qubit with quantum states of a macrosco pic body. The question then arises whether slow decoherence of quantum oscillations of the cur rent is consistent with fast decoherence of quantum states of a macroscopic solid. This problem is ana lyzed within an exactly solvable quantum model of a qubit embedded in …

Collapse Of Skyrmions In Two-Dimensional Ferromagnets And Antiferromagnets, Luifei Cai, Eugene M. Chudnovsky, Dmitry A. Garanin

Publications and Research

Collapse of a skyrmion due to the discreteness of a crystal lattice in isotropic two-dimensional ferro- and antiferromagnets has been studied analytically and by numerical solution of equations of motion for up to 2000 x 2000 classical spins on a square lattice coupled via Heisenberg exchange interaction. Excellent agreement between analytical and numerical results has been achieved. The lifetime of the skyrmion scales with its initial size, lambda_0, as(lambda_0/a)^5 in ferromagnets and as (lambda_0/a)^2.15 in antiferromagnets, with a being the lattice parameter. This makes antiferromagnetic skyrmions significantly shorter lived than ferromagnetic skyrmions.

Dipolar-Controlled Spin Tunneling And Relaxation In Molecular Magnets, Dmitry A. Garanin

Publications and Research

Spin tunneling in molecular magnets controlled by dipole-dipole interactions (DDI) in the disordered state has been considered numerically on the basis of the microscopic model using the quantum mean-field approximation. In the actual case of a strong DDI spin coherence is completely lost and there is a slow relaxation of magnetization, described by t^{3/4} at short times. Fast precessing nuclear spins, included in the model microscopically, only moderately speed up the relaxation.

Cosmic String Interactions Induced By Gauge And Scalar Fields, Daniel N. Kabat, Debajyoti Sarkar

Publications and Research

We study the interaction between two parallel cosmic strings induced by gauge fields and by scalar fields with non-minimal couplings to curvature. For small deficit angles the gauge field behaves like a collection of non-minimal scalars with a specific value for the non-minimal coupling. We check this equivalence by computing the interaction energy between strings at first order in the deficit angles. This result provides another physical context for the "contact terms" which play an important role in the renormalization of black hole entropy due to a spin-1 field.

Holographic Representation Of Bulk Fields With Spin In Ads/Cft, Daniel N. Kabat, Gilad Lifschytz, Shubho Roy, Debajyoti Sarkar

Publications and Research

We develop the representation of bulk fields with spin one and spin two in anti-de Sitter space, as non-local observables in the dual CFT. Working in holographic gauge in the bulk, at leading order in 1/N bulk gauge fields are obtained by smearing boundary currents over a sphere on the complexified boundary, while linearized metric fluctuations are obtained by smearing the boundary stress tensor over a ball. This representation respects AdS covariance up to a compensating gauge transformation. We also consider massive vector fields, where the bulk field is obtained by smearing a non-conserved current. We compute bulk two-point functions …

Quantum Deflagration And Supersonic Fronts Of Tunneling In Molecular Magnets, Dmitry A. Garanin, Saaber Shoyed

Publications and Research

Theory of magnetic deflagration taking into account dipolar-controlled spin tunneling has been applied to the realistic model of molecular magnet Mn_12 Ac. At small transverse field, the front speed v has tunneling maxima on the bias field B_z reflecting those of the molecular spin's relaxation rate calculated from the density-matrix equation. At high transverse field, spin tunneling directly out of the metastable ground state leads to front speeds that can exceed the speed of sound. Both for the weak and strong transverse field, the spatial profile of the deflagration front near tunneling resonances shows a front of tunneling that triggers …

Thermal Analysis Of Organically Modified Siloxane Melting Gels, Andrei Jitianu, Kristin Lammers, Georgia A. Arbuckle-Kiel, Lisa C. Klein

Publications and Research

Hybrid melting gels were prepared by a sol–gel process, starting with a mono-substituted siloxane and a disubstituted siloxane, methyltrimethoxysilane (MTES) together with dimethyldimethoxysilane (DMDES). Five gel compositions were prepared with concentrations between 50% MTES–50% DMDES and 75% MTES–25% DMDES (in mol.%).

Synthesis Of Melting Gels Using Mono-Substituted And Di-Substituted Alkoxysiloxanes, Lisa Klein, Andrei Jitianu

Publications and Research

Hybrid organic-inorganic sol-gel materials containing silica were first called “ORMOSILs” in 1984.¹ Since then, the number of hybrid organicinorganic combinations has increased rapidly.² Hybrid materials have remarkable features resulting from the synergistic combination of both inorganic and organic components that make them suitable for a wide range of applications such as electrochemical devices, biomedical applications including drug delivery, and electronic and optoelectronic applications including light-emitting diodes, photodiodes, solar cells, gas sensors and field effect transistors.

Generally, organic-inorganic materials are classified in two broad categories: Class I materials where the organic and inorganic components are embedded one within the …

Study Of The Gelling Process In The La-Co-Citric Acid System, Luminita Predoana, Andrei Jitianu, Barbara Malic, Maria Zaharescu

Publications and Research

The gelling process in the aqueous lanthanum-cobalt-citric acid system was studied using UV-VIS and IR spectroscopic methods, as well as viscosity measurements, to establish the gelling mechanism of transition metal ions (La3+ and Co2+) in the presence of chelating agent. Lanthanum and cobalt nitrates and lanthanum and cobalt acetates, respectively, were used as starting reagents, and the citric acid was used as chelating agent. The gelation process was investigated at room temperature and at 80°C. At elevated temperature, the gels were obtained after 30 h, whereas at room temperature, these were obtained in 1 month. Complex gels were formed for …

Reducibility, Degree Spectra, And Lowness In Algebraic Structures, Rebecca M. Steiner

Dissertations, Theses, and Capstone Projects

This dissertation addresses questions in computable structure theory, which is a branch of mathematical logic hybridizing computability theory and the study of familiar mathematical structures. We focus on algebraic structures, which are standard topics of discussion among model theorists. The structures examined here are fields, graphs, trees under a predecessor function, and Boolean algebras.

For a computable field F, the splitting set S_F of F is the set of polynomials in F[X] which factor over F, and the root set R_F of F is the set of polynomials in F[X] which have a root in F …

Aperture Array Photonic Metamaterials: Theoretical Approaches, Numerical Techniques And A Novel Application, Eli Lansey

Dissertations, Theses, and Capstone Projects

Optical or photonic metamaterials that operate in the infrared and visible frequency regimes show tremendous promise for solving problems in renewable energy, infrared imaging, and telecommunications. However, many of the theoretical and simulation techniques used at lower frequencies are not applicable to this higher-frequency regime. Furthermore, technological and financial limitations of photonic metamaterial fabrication increases the importance of reliable theoretical models and computational techniques for predicting the optical response of photonic metamaterials.

This thesis focuses on aperture array metamaterials. That is, a rectangular, circular, or other shaped cavity or hole embedded in, or penetrating through a metal film. The research …

Optomechanics Of Cavity Driven Nanoparticles, Joel T. Rubin

Dissertations, Theses, and Capstone Projects

The subject of this thesis is the opto-mechanical interaction of a spherical high-Q microresonator and a subwavelength particle, which, at optical wavelengths, corresponds to a size on the order of nanometers. After a review of the basic theory of spherical resonators and multi-sphere scattering, the full self-consistent electromagnetic field of the coupled resonator-particle system is derived. The particle-induced frequency shift and broadening is calculated by examining the poles of the scattering coefficients of the resonator. The force exerted on the particle by the field is determined via the Maxwell stress tensor, and is found to be in general non-conservative. From …