Physical Sciences and Mathematics Commons^™

A Grey-Box Approach To Automated Mechanism Design, Jinzhong Niu, Kai Cai, Simon Parsons, Xin Yao, Maria Fasli

Publications and Research

This paper presents an approach to automated mechanism design in the domain of double auctions. We describe a novel parameterized space of double auctions, and then introduce an evolutionary search method that searches this space of parameters. The approach evaluates auction mechanisms using the framework of the TAC Market Design Game and relates the performance of the markets in that game to their constituent parts using reinforcement learning. Experiments show that the strongest mechanisms we found using this approach not only win the Market Design Game against known, strong opponents, but also exhibit desirable economic properties when they run in …

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.

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 …

The Effect Of Dissolved Humic Acids On Aluminosilicate Formation And Associated Carbon Sequestration, Ashaki A. Rouff, Brian L. Phillips, Stacey G. Cochiara, Kathryn L. Nagy

Publications and Research

Allophane and imogolite neogenesis in soils may occur in the presence of organic matter. To understand this process under conditions relevant to soils, the influence of dissolved organic carbon (DOC) as humic acid (HA), on aluminosilicate formation was studied at 25◦C, pH 6, and low-DOC concentrations. For solutions with initial Al/Si ratios of 1–2.1, and 0–6mg/L DOC, precipitates recovered after 20h had Al/Si ratios of 2.2–2.7. The formation of allophane, imogolite-like material, and aluminosilicate gel was confirmed by XRD, FTIR, and NMR. The effect of DOC was to produce a small, but systematic increase in imogolite-like Si in the precipitate, …

Beefmoves: Dissemination, Diversity, And Dynamics Of English Borrowings In A German Hip Hop Forum, Matt Garley, Julia Hockenmaier

Publications and Research

We investigate how novel English-derived words (anglicisms) are used in a German-language Internet hip hop forum, and what factors contribute to their uptake.

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.%).

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 …

Equivariant Degenerations Of Spherical Modules For Groups Of Type A, Stavros Argyrios Papadakis, Bart Van Steirteghem

Publications and Research

Let G be a complex reductive algebraic group. Fix a Borel subgroup B of G and a maximal torus T in B. Call the monoid of dominant weights L+ and let S be a finitely generated submonoid of L+. V. Alexeev and M. Brion introduced a moduli scheme MS which classifies affine G-varieties X equipped with a T-equivariant isomorphism SpecC[X]U → SpecC[S], where U is the unipotent radical of B. Examples of MS have been obtained by S. Jansou, P. Bravi and S. Cupit-Foutou. In this paper, we prove that MS is isomorphic to an affine space when S is …

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 …

Ledzewicz Applies Math To Health Sciences, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Hamad Studies, Teaches Properties Of Light, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Minchin Studies, Teaches Conservation Issues, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Ackad Uses Power Computers To Solve Problems, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

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.

Studies On Sucralose-Based Low Molecular Weight Gelators, Malick Samateh

Dissertations and Theses

Amphiphiles are molecules with both hydrophilic head and hydrophobic tail groups. Examples of amphiphiles include surfactants, detergents, soaps, bile acids/salts and lipids. Due to their amphiphilic nature, they tend to self-assemble in solution via non-covalent interactions such as hydrogen-bonding, π-π stacking and donor–acceptor interactions to form hierarchical morphologies like micelles, lamellae and fibers. The ones capable of subsequently forming gels are known as low molecular weight gelators (LMWGs). LMWGs usually form “polymer-like” fibers that interact to form a three-dimentional network known as a Self-Assembled Fibrillar Network (SAFIN), which entraps and immobilizes the entire solvent pool to form a viscoeslatic material …

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 …

Azide-Benzyne Cycloaddition And Olefination To Vinyl Benzotriazoles, Singh Govindra

Dissertations and Theses

No abstract provided.

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, …

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

Dissertations and Theses

No abstract provided.

Developing A Comprehensive Software Toolkit For Creating Digital Mosaic Artwork, Dmitry Bosikov

Dissertations and Theses

No abstract provided.

Rapid Decoding Of Digital Data Streams Using Field Programmable Gate Arrays, Andrew Hernandez

Dissertations and Theses

No abstract provided.

Context Awareness And Discovery For Helping The Blind, Martin Goldberg

Dissertations and Theses

No abstract provided.

Re-Engineering Ccny's Business Process Of The Non-Tax Levy Disbursements Requisitions, Ferguson Rodley

Dissertations and Theses

No abstract provided.

Diffuse Optical Imaging Using Decomposition Methods, Binlin Wu, M. Alrubaiee, W. Cai, M. Xu, S. K. Gayen

Publications and Research

Diffuse optical imaging (DOI) for detecting and locating targets in a highly scattering turbid medium is treated as a blind source separation (BSS) problem. Three matrix decomposition methods, independent component analysis (ICA), principal component analysis (PCA), and nonnegative matrix factorization (NMF) were used to study the DOI problem. The efficacy of resulting approaches was evaluated and compared using simulated and experimental data. Samples used in the experiments included Intralipid-10% or Intralipid-20% suspension in water as the medium with absorptive or scattering targets embedded.

Fluids, Anomalies And The Chiral Magnetic Effect: A Group-Theoretic Formulation, V. Parameswaran Nair, Rashmi Ray, Shubho Roy

Publications and Research

It is possible to formulate fluid dynamics in terms of group-valued variables. This is particularly suited to the cases where the fluid has nonabelian charges and is coupled to nonabelian gauge fields. We explore this formulation further in this paper. An action for a fluid of relativistic particles (with and without spin) is given in terms of the Lorentz and Poincare (or de Sitter) groups. Considering the case of particles with flavor symmetries, a general fluid action which also incorporates all flavor anomalies is given. The chiral magnetic and chiral vorticity effects as well as the consequences of the mixed …

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 …

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 …