Physical Sciences and Mathematics Commons^™

A Heteroscedastic, Rank-Based Approach For Analyzing 2 X 2 Independent Groups Designs, Laura Mills, Robert A. Cribbie, Wei-Ming Luh

Journal of Modern Applied Statistical Methods

The ANOVA F is a widely used statistic in psychological research despite its shortcomings when the assumptions of normality and variance heterogeneity are violated. A Monte Carlo investigation compared Type I error and power rates of the ANOVA F, Alexander-Govern with trimmed means and Johnson transformation, Welch-James with trimmed means and Johnson Transformation, Welch with trimmed means, and Welch on ranked data using Johansen’s interaction procedure. Results suggest that the ANOVA F is not appropriate when assumptions of normality and variance homogeneity are violated, and that the Welch/Johansen on ranks offers the best balance of empirical Type I error …

Axiomatic Equilibrium Selection For Generic Two-Player Games, Srihari Govindan, Robert B. Wilson

Robert B Wilson

We impose three conditions on refinements of the Nash equilibria of finite games with perfect recall that select closed connected subsets, called solutions. A. Each equilibrium in a solution uses undominated strategies; B. Each solution contains a quasi-perfect equilibrium; C. The solutions of a game map to the solutions of an embedded game, where a game is embedded if each player's feasible strategies and payoffs are preserved by a multilinear map. We prove for games with two players and generic payoffs that these conditions characterize each solution as an essential component of equilibria in undominated strategies, and thus a stable …

New Observations Of Gas-Phase Expansion Above A Dense Non-Aqueous Phase Liquid Pool, Kevin G. Mumford, James E. Smith, Sarah E. Dickson

Sarah E Dickson

The partitioning of volatile dense nonaqueous phase liquid (DNAPL) compounds to a discontinuous gas phase results in the repeated expansion, fragmentation, and vertical mobilization of gas clusters. This process has the potential to significantly affect the dissolution of DNAPL source zones and the characterization of DNAPL-contaminated sites, but has not been included in common conceptual models. This study presents new observations of discontinuous gas-phase growth above a 1,1,1-trichloroethane pool in a two-dimensional flow cell packed with 1.1-mm diameter sand. In contrast to the behavior observed in coarse glass beads, these visualization results show that the gas phase evolves as a …

Logistic Regression Using R, Joseph Hilbe

Joseph M Hilbe

R code and output for examples in Logistic Regression Models, Chapman & Hall/CRC (2009)

Regio- And Enantioselective N-Allylations Of Imidazole, Benzimidazole, And Purine Heterocycles Catalyzed By Single-Component Metallacyclic Iridium Complexes, Levi M. Stanley, John F. Hartwig

Levi M. Stanley

Highly regio- and enantioselective iridium-catalyzed N-allylations of benzimidazoles, imidazoles, and purines have been developed. N-Allylated benzimidazoles and imidazoles were isolated in high yields (up to 97%) with high branched-to-linear selectivity (up to 99:1) and enantioselectivity (up to 98% ee) from the reactions of benzimidazole and imidazole nucleophiles with unsymmetrical allylic carbonates in the presence of single component, ethylene-bound, metallacyclic iridium catalysts. N-Allylated purines were also obtained in high yields (up to 91%) with high N9/N7 selectivity (up to 96:4), high branched-to-linear selectivity (98:2), and high enantioselectivity (up to 98% ee) under similar conditions. The reactions encompass a range of benzimidazole, …

Minimizing Detection Probability Routing In Ad Hoc Networks Using Directional Antennas, Xiaofeng Lu, Donald Towsley, Pietro Lio, Fletcher Wicker, Zhang Xiong

Donald F. Towsley

In a hostile environment, it is important for a transmitter to make its wireless transmission invisible to adversaries because an adversary can detect the transmitter if the received power at its antennas is strong enough. This paper defines a detection probability model to compute the level of a transmitter being detected by a detection system at arbitrary location around the transmitter. Our study proves that the probability of detecting a directional antenna is much lower than that of detecting an omnidirectional antenna if both the directional and omnidirectional antennas provide the same Effective Isotropic Radiated Power (EIRP) in the direction …

Seedlings’ Substrate Preferences In A Minnesota Old Growth Thuja-Betula Forest, Stephen C. Rossiter

Environmental Studies Honors Papers

Northeastern Minnesota’s logging history has altered the forests enough to cause concern about the reproduction of Thuja occidentalis and Betula alleghaniensis. I studied a rare old growth example of an already rare mesic Thuja-Betula forest and asked how well those species were regenerating in that mostly unaltered ecosystem. In managed forests, a lack of suitable substrate is thought to be limiting their seedling establishment so I asked which substrates the seedlings preferred in the old forest. To answer both questions, I measured the seedling densities of all canopy tree species across height classes and substrate types within twenty 100m2 plots. …

Seasons, Storms And Seawalls: A Comparison Of Constrained And Unconstrained Beaches In Groton, Connecticut, Katherine A. Serafin

Environmental Studies Honors Papers

A study was done in order to evaluate the impact of a seawall on a beach in Groton, Connecticut. Literature predicts beaches containing seawalls will inhibit functioning as a normal beach and lead to increased erosion. Groton Long Point is developed and backed by a seawall while Bluff Point is located on a state park and receives much less human usage. Profiles were measured to study the effect of storms, seasonality and time on these two barrier beaches. Two transects at each beach were used to determine changes in profiles throughout the year. Profiles were then compared to previous research …

Observation And Modeling Of Source Effects In Coda Wave Interferometry At Pavlof Volcano, Matthew M. Haney, Kasper Van Wijk, Leiph A. Preston, David F. Aldridge

CGISS Publications and Presentations

We examine seismic records of repeating explosions from Pavlof volcano, Alaska, during its 2007 eruption. Repetitive explosions are typical of Strombolian-style eruptions and allow measurement of relative time shifts between similar late-arriving phases using the technique called coda wave interferometry (Snieder et al., 2002). The measurements enable the detection of small changes in the volcanic interior of Pavlof. We are able to resolve an increase in the relative traveltime change of late-arriving seismic waves on the order of 0.3% over the course of two weeks. Based on the spectra of the explosions, their location inside the magma conduit, previous studies …

Copper(Ii) Catalyzed Aminomethylation Of Alkanes With Amine N-Oxides Via C-H Bond Activation, Matthew Cipolla

Senior Honors Projects

The formation of a C-C bond via double C-H bond activation is very challenging. There are only a few examples of such a coupling having been accomplished. Only one of these examples consists of a coupling of two sp3 hybridized carbons. I set out to reproduce this coupling, using substrates that would have a functional application to the synthesis of appealing molecules such as bioactive molecules. Cyclohexane and trimethylamine N-oxide were successfully coupled via a double C-H bond activation, catalyzed by copper(II). Current research now involves the coupling of toluene with trimethylamine N-oxide. As this work progresses, more interesting and …

Σary, Minnesota State University Moorhead, Mathematics Department

Math Department Newsletters

No abstract provided.

Does A Co-Learner Delivery Model In Professional Development Affect Teachers’ Self-Efficacy In Teaching Mathematics, John J. Ribeiro, Denise Demagistris

Teacher Education

A mixed method study is reported examining teacher efficacy regarding professional development in mathematics instruction for two groups of teachers: in building with peers (N=17) and MAT student co-learners in the classroom (N=14). An end-of-course survey, focus group interviews and pre-post data for the Teacher Self Efficacy Scale were used to investigate:1. What is the difference in teachers’ efficacy regarding mathematics instruction based on the professional development delivery system they experienced? 2. What are teachers’ perceptions of their professional development with peers conducted onsite in district compared with professional development with peers and preservice teachers at a university setting? Descriptive …

Pairing Software-Managed Caching With Decay Techniques To Balance Reliability And Static Power In Next-Generation Caches, Kelly Shaw, Margaret Martonosi

Department of Math & Statistics Technical Report Series

Since array structures represent well over half the area and transistors on-chip, maintaining their ability to scale is crucial for overall technology scaling. Shrinking transistor sizes are resulting in increased probabilities of single events causing single- and multi-bit upsets which require adoption of more complex and power hungry error detection and correction codes (ECC) in hardware. At the same time, SRAM leakage energy is increasing partly due to technology trends and partly due to the increasing number of transistors present.

This paper proposes and evaluates methods of reducing the static power requirements of caches, while also maintaining high reliability. In …

The Effectiveness Of Institutional Intervention At Minimizing Demographic Inertia And Improving The Representation Of Women Faculty In Higher Education, Amanda V. Bakian

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Across all science and engineering disciplines, women currently receive 46% of the doctoral degrees granted annually. Despite gains in doctoral degrees earned by women over the past 30 years, they remain under-represented among full time tenured /tenure-track science and engineering faculty compared to their presence among degree recipients. The inequality gap is widest among full professors at 4 year research universities where women account for a mere 16% of all S&E full time full professors. Multiple hypothesis have been proposed to account for women's under-representation relative to men including those based on human capital/economic theory, feminist theory, innate biological gender …

Random Motion And The Diffusion Of Brine Shrimp: A Project Based Learning Unit, Rebecca Atkins

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Over the years, there have been several trends, philosophies, and ideas about how mathematics should be taught. These have included progressive movements, essentialist movements, drill and practice, teacher-centered methodologies, student-centered methodologies, and others. However, despite these various instructional trends, research has found that mathematics teachers have basically taught the same way for years, with little or no variation with respect to the changing trends (Ward, 2001). For many students, the traditional teaching method employed in their mathematics classes is typically centered on the teacher and includes lecture in which the teacher provides the necessary definitions and notations and does several …

Using Real-World Data As A Basis For Problem-Based Learning: Investigating Preservation Biases Of Fish In Fossil Butte National Monument, Blair Larsen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

This project examined the design and development of an online problem-based learning module to teach earth-system science to K-12 educators. The module revolved around identifying earth sphere (lithosphere, hydrosphere, biosphere and atmosphere) interactions needed to produce mass fish mortality layers found in the Green River Formation at Fossil Butte National Monument. Students investigated the unique earth sphere combinations needed to produce mass fish mortality layers, reflected on the formation of such deposits, and examined the impact of these earth spheres on the earth system. As a supplement to the course, the students also analyzed data on fossils collected from a …

Assessing Access Of Galactic Cosmic Rays At Moon's Orbit, Chia-Lin L. Huang, Harlan E. Spence, B. T. Kress

Physics & Astronomy

[1] Characterizing the lunar radiation environment is essential for preparing future robotic and human explorations on lunar bases. Galactic cosmic rays (GCR) represent one source of ionizing radiation at the Moon that poses a biological risk. Because GCR are charged particles, their paths are affected by the magnetic fields along their trajectories. Unlike the Earth, the Moon has no strong, shielding magnetic field of its own. However, as it orbits Earth, the Moon traverses not only the weak interplanetary magnetic field but also the distant magnetic tail of Earth's magnetosphere. We combine an empirical magnetic field model of Earth's magnetosphere …

Traffic Analysis For The Calibration Of Risk Assessment Methods, Brian R. Calder, Schwehr Kurt

Center for Coastal and Ocean Mapping

In order to provide some measure of the uncertainty inherent in the sorts of charting data that are provided to the end-user, we have previously proposed risk models that measure the magnitude of the uncertainty for a ship operating in a particular area. Calibration of these models is essential, but the complexity of the models means that we require detailed information on the sorts of ships, traffic patterns and density within the model area to make a reliable assessment. In theory, the ais system should provide this information for a suitably instrumented area. We consider the problem of converting, filtering …

In-Implanted Zno: Controlled Degenerate Surface Layer, David C. Look, Gary C. Farlow, F. Yaqoob, L. H. Vanamurthy, M. Huang

Physics Faculty Publications

In was implanted into bulk ZnO creating a square profile with a thickness of about 100 nm and an In concentration of about 1×10²⁰ cm^-3. The layer was analyzed with Rutherford backscattering, temperature-dependent Hall effect, and low-temperature photoluminescence measurements. The implantation created a nearly degenerate carrier concentration n of about 2×10¹⁹ cm^-3, but with a very low mobility μ, increasing from about 0.06 cm²/V s at 20 K to about 2 cm²/V s at 300 K. However, after annealing at 600 °C for 30 min, n increased to about 5×10 …

Organocuprate Mediated Syntheses Of O, And N-Heterocycles, Fenghai Guo

All Dissertations

ABSTRACT
The δ-lactone moiety comprises structural subunits in a number of natural products. Highly substituted δ-lactones are important both in synthetic applications and also as naturally occurring compounds. We have reported a one-pot procedure for the synthesis of trans-4,5-disubstituted tetrahydropran-2-ones from 3-hydroxy-3,6-dihydropyran-2-one involving sequential cuprate mediated allylic substitution and 1,4-conjugate addition reactions. We have now examined the same protocol for synthesis of 4,5,6-trisubstituted δ-lactones.
The rich functionalities(i.e. the epoxide, olefin and ester functional groups) in ,δ-epoxy-α,β-enoates provide opportunities for SN2-epoxide opening, allylic substitution, and 1,4-conjugated addtion. The opening of the epoxide with AcCl, AcBr, and benzoyl chloride afforded the -acetoxy--halo-,-enoates …

Intersections And Representations Of Graphs, John Light

All Dissertations

Given two graphs G and H sharing the same vertex set, the edge-intersection spectrum of G and H is the set of possible
sizes of the intersection of the edge sets of both graphs. For example,
the spectrum of two copies of the cycle C₅ is {0, 2, 3, 5}, and the spectrum of two copies of the star K_1,r is {1, r}. The intersection spectrum was initially studied for designs by Lindner and Fu and others and was originally extended to graphs by Eric Mendelsohn. Several examples are studied, both when G and H are isomorphic and …

On Elliptic Curves, Modular Forms, And The Distribution Of Primes, Ethan Smith

All Dissertations

In this thesis, we present four problems related to elliptic curves, modular forms, the distribution of primes, or some combination of the three. The first chapter surveys the relevant background material necessary for understanding the remainder of the thesis. The four following chapters present our problems of interest and their solutions. In the final chapter, we present our conclusions as well as a few possible directions for future research.
Hurwitz class numbers are known to have connections to many areas of number theory. In particular, they are intimately connected to the theory of binary quadratic forms, the structure of imaginary …

Recovery Of Fathead Minnows (Pimephales Promelas) Following Episodic Copper Exposure: A Biochemical, Physiological, Individual, And Population Perspective, Holly Zahner

All Dissertations

The US EPA utilizes the Biotic Ligand Model (BLM) when developing site-specific water-quality criteria for copper. The BLM was calibrated using toxicity data from fixed duration continuous exposures (48 or 96h LC50). However, exposures of copper in natural aquatic systems typically vary in concentration, duration, and may occur multiple times over the life-span of an organism. Additionally, organisms will experience periods in copper free water, potentially allowing them to detoxify and recover homeostasis. Yet, the BLM framework does not consider brief exposures (<24h), multiple exposures, latent responses, or organism recovery, potentially resulting in an inaccurate assessment of exposure toxicity. A recently proposed physiologically-based addition to the BLM will extend the applicability of the framework to brief, multiple pulse copper exposures. Thus, the overall goal of this research was to characterize the recovery of larval Pimephales promelas following episodic copper exposure at a biochemical, physiological, individual, and population level.
The response of whole-body sodium, whole-body Na+/K+-ATPase, and whole-body carbonic anhydrase in larval P. promleas was quantified …

New Directions In Multivariate Public Key Cryptography, Raymond Heindl

All Dissertations

Most public key cryptosystems used in practice are based on integer factorization or discrete logarithms (in finite fields or elliptic curves). However, these systems suffer from two potential drawbacks. First, they must use large keys to maintain security, resulting in decreased efficiency. Second, if large enough quantum computers can be built, Shor's algorithm will render them completely insecure.
Multivariate public key cryptosystems (MPKC) are one possible alternative. MPKC makes use of the fact that solving multivariate polynomial systems over a finite field is an NP-complete problem, for which it is not known whether there is a polynomial algorithm on quantum …

Investigation Of Photophysical And Photochemical Processes In Conjugated Polymer Nanoparticles By Single Particle And Ensemble Spectroscopy, Craig Szymanski

All Dissertations

Single molecule imaging has emerged as a powerful tool in a range of applications, but the field is limited by a lack of fluorescent probes with sufficient brightness and photostability for many demanding applications such as tracking of single biomolecules in cells and tissues at video rate with 1 nm spatial resolution. Conjugated polymers hold great promise as a solution to these issues, with a high density of π electrons and variety of chemistries, allowing efficient and tunable absorption of light. This dissertation describes the development and characterization of a novel type of nanoparticle composed of conjugated polymer called CPdots. …

Synthesis Of Ionic Liquid Monomers Using Fluorinated Sulfonyl Imide Anions And The 1,3-Dialkylimidazolium Cation, Thomas Hickman

All Dissertations

With their unique material and solvent properties, ionic liquids have seen an amazing, exponential increase in interest. After a brief introduction of select areas of interest for these compounds, this thesis mainly focuses on the development of novel polyfunctional ionic liquids and polymeric ionic liquids.
One of the preferred anions for ionic liquids is the bis((trifluoromethyl)sulfonyl) imide anion, first introduced by our group in 1982. It shows excellent thermal stability and the desired resonance delocalization of a negative charge for ionic liquids. A series of monofunctional, difunctional, and multi-functional bis(perfluoroalkylsufonyl)imides, along with 1,3-dialkylimidazolium cations were prepared by direct methylation of …

Constructed Wetland Treatment System: An Approach For Mitigating Risks Of Flue Gas Desulfurization Waters, Derek Eggert

All Dissertations

Federal laws regarding ambient air quality are currently requiring industries to reduce emissions of sulfur dioxides (SO2). Coal-fired power plants have therefore begun implementing flue gas desulfurization (FGD) scrubbers that utilize a highly oxygenated water stream (calcium carbonate saturated water) to transform sulfur gases into soluble anion species (e.g. sulfite and sulfate). This FGD process also transfers potentially toxic constituents including arsenic, cadmium, chemical oxygen demand, copper, mercury, selenium, chloride, sulfates, and zinc into the scrubbing water. These scrubber waters, referred to as FGD waters, present an industrial problem due to the large volumes produced (378,000 to 1,900,000 L/day) and …

Shoreline Features Of Titan’S Ontario Lacus From Cassini/Vims Observations, Jason W. Barnes, Robert H. Brown, Jason M. Soderblom, Laurence A. Soderblom, Ralf Jaumann, Brian Jackson, Christophe Sotin, Bonnie J. Buratti, Karly M. Pitman, Kevin H. Baines, Roger N. Clark, Phillip D. Nicholson, Elizabeth P. Turtle, Jason Perry

Brian Jackson

We analyze observations of Titan's south polar lake Ontario Lacus obtained by Cassini's Visual and Infrared Mapping Spectrometer during the 38th flyby of Titan (T38; 2007 December 5). These near-closest-approach observations have the highest signal-to-noise, the finest spatial resolution, and the least atmospheric influence of any near-infrared lake observation to date. We use the large, spatially flat, and low-albedo interior of Ontario Lacus as a calibration target allowing us to derive an analytical atmospheric correction for emission angle. The dark lake interior is surrounded by two separate annuli that follow the lake interior's contours. The inner annulus is uniformly dark, …

Investigations Into Mapping Lava Flows In The Snake River Plain, Idaho, Vinita Ruth Hobson-Broko

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The origin of the Snake River plain continues to be debated, but the plume model is most popular at the current time. Some theories, such as meteorite impact, have been excluded, but the remaining theories require more scrutiny.

Various methods of examining phenomena in the Snake River Plain were employed. Unsupervised classification of Landsat ETM data indicates that spectra can be used to differentiate between flows. However, photographs of flows at Craters of the Moon National Monument show wide variations in texture and color within a single flow. Vegetation grows preferentially on the smoother pahoehoe slabs and significantly impacting the …

Quantile Regression: On Inferences About The Slopes Corresponding To One, Two Or Three Quantiles, Rand R. Wilcox, Kathleen Costa

Journal of Modern Applied Statistical Methods

The problem of testing hypotheses about the slope of a quantile regression line when the sample size is small is considered. A modified bootstrap method is suggested that is found to have certain advantages over the inverse rank method recommended by Koenker (1994). A method is suggested that simultaneously controls the probability of at least one Type I error when performing two or three tests corresponding to two or three specific quantiles. Using data from actual studies, it is illustrated that the new method can yield substantially shorter confidence intervals than the rank inverse method and, even with a large …