Physical Sciences and Mathematics Commons^™

Sums Of Gauss Sums And Weights Of Irreducible Codes, Robert W. Fitzgerald, Joseph L. Yucas

Articles and Preprints

We develop a matrix approach to compute a certain sum of Gauss sums which arises in the study of weights of irreducible codes. A lower bound on the minimum weight of certain irreducible codes is given.

Symbolic Dynamics And Its Applications, Michael C. Sullivan

Articles and Preprints

Book review of Symbolic Dynamics and its Applications, edited by Susan Williams, AMS.

Equivariant Flow Equivalence Of Shifts Of Finite Type By Matrix Equivalence Over Group Rings, Mike Boyle, Michael C. Sullivan

Articles and Preprints

Let G be a finite group. We classify G-equivariant flow equivalence of non-trivial irreducible shifts of finite type in terms of

(i) elementary equivalence of matrices over ZG and

(ii) the conjugacy class in ZG of the group of G-weights of cycles based at a fixed vertex.

In the case G = Z/2, we have the classification for twistwise flow equivalence. We include some algebraic results and examples related to the determination of E(ZG) equivalence, which involves K₁(ZG).

Twistwise Flow Equivalence And Beyond..., Michael C. Sullivan

Articles and Preprints

An expository account of recent progress on twistwise flow equivalence. There is a new result in the appendix. (Appendix joint with Mike Boyle.)

Knots On A Positive Template Have A Bounded Number Of Prime Factors., Michael C. Sullivan

Articles and Preprints

Templates are branched 2-manifolds with semi-flows used to model "chaotic" hyperbolic invariant sets of flows on 3-manifolds. Knotted orbits on a template correspond to those in the original flow. Birman and Williams conjectured that for any given template the number of prime factors of the knots realized would be bounded. We prove a special case when the template is positive; the general case is now known to be false.

Real Numbers With Polynomial Continued Fraction Expansions, James Mclaughlin, Nancy Wyshinski

Mathematics Faculty Publications

In this paper we show how to apply various techniques and theorems (including Pincherle’s theorem, an extension of Euler’s formula equating infinite series and continued fractions, an extension of the corresponding transformation that equates infinite products and continued fractions, extensions and contractions of continued fractions and the Bauer-Muir transformation) to derive infinite families of in-equivalent polynomial continued fractions in which each continued fraction has the same limit. This allows us, for example, to construct infinite families of polynomial continued fractions for famous constants like π and e, ζ(k) (for each positive integer k ≥ 2), various special functions evaluated at …

Measuring Shared Information And Coordinated Activity In Neuronal Networks, K L. Klinkner, C R. Shalizi, Marcelo Camperi

Physics and Astronomy

Most nervous systems encode information about stimuli in the respond- ing activity of large neuronal networks. This activity often manifests itself as dynamically coordinated sequences of action potentials. Since multiple electrode recordings are now a standard tool in neuroscience research, it is important to have a measure of such network-wide behav- ioral coordination and information sharing, applicable to multiple neural spike train data. We propose a new statistic, informational coherence , which measures how much better one unit can be predicted by knowing the dynamical state of another. We argue informational coherence is a measure of association and shared information …

Quantification Of Call Variations Between Sub-Regional Florida Scrub Jay (Aphelocoma Coerulescens) Populations, Kory C. Russel

Master of Environmental Science (MES) Theses

The Florida Scrub Jay (Aphelocoma coerulescens) has seen significant and accelerating declines in its overall population numbers in the past 100 years. This is primarily the result of habitat loss and population fragmentation, which has isolated the extremely territorial Florida Scrub Jay into smaller sub-regional populations. In many ways this is a catalyst for social evolution and divergence of the species. An early indicator of divergent evolution can be witnessed in the development of distinct call dialects. By recording the female hiccup calls of the three largest distinct sub-regional populations (Atlantic Coast sub-region, Ocala sub-region and the Lake …

The Planet, 2005, Winter, Laurie Ballew, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.

Huxley Horizon, 2005, Winter, Huxley College Of The Environment, Western Washington University

Historical Collection of Huxley Newsletters

No abstract provided.

State Aggregation And Population Dynamics In Linear Systems, Jonathan E. Rowe, Michael D. Vose, Alden H. Wright

Computer Science Faculty Publications

We consider complex systems that are composed of many interacting elements, evolving under some dynamics. We are interested in characterizing the ways in which these elements may be grouped into higher-level, macroscopic states in a way that is compatible with those dynamics. Such groupings may then be thought of as naturally emergent properties of the system. We formalize this idea and, in the case that the dynamics are linear, prove necessary and sufficient conditions for this to happen. In cases where there is an underlying symmetry among the components of the system, group theory may be used to provide a …

Diurnal Water-Pressure Fluctuations: Timing And Pattern Of Termination Below Bench Glacier, Alaska, Usa, T. J. Fudge, Joel T. Harper, Neil Humphrey, W. Tad Pfeffer

Geosciences Faculty Publications

Observations from basal water-pressure sensors along the length of Bench Glacier, Alaska, USA, show that diurnal fluctuations of water pressure are seasonal and restricted to summer. Most notable about these fluctuations is their disappearance in the late summer and early autumn, long before the seasonal end of diurnal meltwater input. Here we present data documenting the end of diurnal water-pressure fluctuations during the 2002 and 2003 melt seasons. The end of diurnal fluctuations occurred abruptly in multiple boreholes spaced meters to kilometers apart. There was no obvious spatial progression of termination events, and a clear correlation with meteorological forcing or …

Evolution Of Subglacial Water Pressure Along A Glacier’S Length, Joel T. Harper, Neil Humphrey, W. Tad Pfeffer, T. J. Fudge, Shad O'Neel

Geosciences Faculty Publications

Observations from along the length of Bench Glacier, Alaska, USA, show that the subglacial water-pressure field undergoes a multiphase transition from a winter mode to a summer mode. Data were collected at the glacier surface, the outlet stream, and in a network of 47 boreholes spanning the length of the 7 km long glacier. The winter pressure field was near overburden, with low-magnitude (centimeter to meter scale) and long-period (days to weeks) variations. During a spring speed-up event, boreholes showed synchronous variations and a slight pressure drop from prior winter values. Diurnal pressure variations followed the speed-up, with their onset …

Generalized Geologic Map For Land-Use Planning: Wayne County, Kentucky, T. Jeffrey Adams, Bart Davidson, Daniel I. Carey

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

Generalized Geologic Map For Land-Use Planning: Spencer County, Kentucky, Bart Davidson, Daniel I. Carey, Stephen F. Greb

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

Generalized Geologic Map For Land-Use Planning: Oldham County, Kentucky, Bart Davidson, Daniel I. Carey, Stephen F. Greb, Anthony Mount

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

Generalized Geologic Map For Land-Use Planning: Franklin County, Kentucky, Brandon C. Nuttall, Bart Davidson, Daniel I. Carey, Courtney Snapp

Map and Chart--KGS

This map is not intended to be used for selecting individual sites. Its purpose is to inform land-use planners, government officials, and the public in a general way about geologic bedrock conditions that affect the selection of sites for various purposes. The properties of thick soils may supercede those of the underlying bedrock and should be considered on a site-to-site basis. At any site, it is important to understand the characteristics of both the soils and the underlying rock.

Diversity In Information And Communication Technologies: The Cost Of Lost Opportunities, Susan Gail Webb

Research outputs pre 2011

The Information and Communication Technology (ICT) industry develops products that are used by many people regardless of gender, age, social status, ethnicity, or religion. Technology has had a significant impact on the way that information is produced, stored and communicated, especially in the fields that have traditionally been heavy producers of information such as libraries and education institutions. Though all types of people use technology, not all types of people are involved in the design and development of technology. Women represent just twenty percent of Australian ICT professionals. They often receive less pay than their male colleagues and are greatly …

Domination Graphs Of Tournaments And Other Digraphs, Deborah J. Bergstrand, L. M. Friedler

Mathematics & Statistics Faculty Works

No abstract provided.

Who Are Resource Nonusers And What Can They Tell Us About Nonuse Values? Decomposing User And Nonuser Willingness To Pay For Coastal Wetland Restoration, Robert J. Johnston, James J. Opaluch, Gisele Magnusson, Marisa J. Mazzotta

Environmental and Natural Resource Economics Faculty Publications

This article assesses the potential for incomplete definitions of resource use to influence estimates of nonuser willingness to pay (WTP), with an emphasis on resources for which an exhaustive set of uses may be difficult to characterize. The data are drawn from a stated preference analysis involving coastal wetland restoration. Results suggest that mechanisms used to distinguish users and nonusers of wetland services may influence estimates of nonuser WTP and that for some attributes, traditional distinctions between user and nonuser WTP may have arguable empirical justification. More broadly, results suggest that relationships among use behaviors and restoration values may be …

Frequency Scanned Interferometer Demonstration System, Jason A. Deibel, Sven Nyberg, Keith Riles, Haijun Yang

Physics Faculty Publications

No abstract provided.

Thermospheric Distribution Of Fast O(D-1) Atoms, V. Kharchenko, A. Dalgarno, Jane L. Fox

Physics Faculty Publications

Detailed calculations are carried out of the sources of energetic metastable O(¹D) atoms in the atmosphere at altitudes between 80 km and 200 km, and the corresponding energy distribution functions are derived, taking account of energy transfer and quenching in collisions of the metastable atoms with the ambient atmospheric gas constituents. The energy relaxation of metastable oxygen atoms produced by O₂ and O₃ photolysis and O₂ ⁺ dissociative recombination is determined by solving the time-dependent Boltzmann equation. The O(¹D) thermalization and quenching times are obtained as functions of the altitude. The steady state …

Differential Tethering Of Log Phase Trypanosoma Brucei Onto Chemically Distinct Surfaces, Darrell R. Fry, Lydia Archuleta, Ashley Dunham, Justin Rains

Faculty Publications

Our long-term objective is to understand and model the motility of T. brucei. Obtaining high quality images of T. brucei that allow one to differentiate between cell body movement and flagallar movement is difficult with T. brucei because the flagellum is attached along the cell body. Currently, our approach his to tether T. brucei onto a microscope friendly surface. The contributions to the ISIS our progress to date. Specifically, we look at the adhesion density of T. brucei to numerous microscope friendly surfaces and at the optimum adhesion conditions for T. brucei.

Drought Preparedness Planning: Building Institutional Capacity, Donald A. Wilhite, Michael Hayes, Cody L. Knutson

Drought Mitigation Center: Faculty Publications

Past attempts to manage drought and its impacts through a reactive, crisis management approach have been ineffective, poorly coordinated, and untimely, as illustrated by the hydro- illogical cycle in Figure 1. The crisis management approach has been followed in both developed and developing countries. Because of the ineffectiveness of this approach, greater interest has evolved in recent years in the adoption of a more proactive risk-based management approach in some countries (see Chapter 6). Other countries are striving to obtain a higher level of preparedness through development of national action programs that are part of the United Nations Convention to …

Discovering Associations Between Climatic And Oceanic Parameters To Monitor Drought In Nebraska Using Data-Mining Techniques, Tsegaye Tadesse, Donald A. Wilhite, Michael J. Hayes, Steve Goddard

Drought Mitigation Center: Faculty Publications

Drought is a complex natural hazard that is best characterized by multiple climatological and hydrological parameters. Improving our understanding of the relationships between these parameters is necessary to reduce the impacts of drought. Data mining is a recently developed technique that can be used to interact with large databases and assist in the discovery of associations between drought and oceanic data by extracting information from massive and multiple data archives. In this study, a new data-mining algorithm [i.e., Minimal Occurrences With Constraints and Time Lags (MOWCATL)] has been used to identify the relationships between oceanic parameters and drought indices. Rather …

Multiple-Year Droughts In Nebraska, Michael J. Hayes, Cody L. Knutson, Q. Steven Hu

Drought Mitigation Center: Faculty Publications

Most people understand that droughts have had a major impact on Nebraska in the past. Yet, many Nebraskans continue to be surprised when drought occurs. It is important to remember that droughts, including multiple-year droughts, are a normal part of Nebraska’s climate. This NebGuide discusses the history of drought in Nebraska, and aims to help Nebraskans better understand the range of climatic variability when they plan for drought.

Fatigue Sensitivity Of Y-Tzp To Microscale Sharp-Contact Flaws, Yu Zhang, Brian R. Lawn

United States Department of Commerce: Staff Publications

The strength degrading effects of sharp-contact damage are examined for Y-TZP ceramic plates bonded to a plastic substrate. Contacts are made with Vickers and Berkovich diamond indenters at low loads (0.1 N to 100 N) in the ceramic lower surfaces prior to bonding to the substrates. The indentations remain in the subthreshold region, that is, without visible corner radial cracks, over the lower region (< 10 N) of the load range. A concentrated load is then applied sinusoidally to the ceramic upper surface, with the loading axis centered on the subsurface indentation flaw, thereby subjecting the flaw to cyclic tension. Relative to polished surfaces, the indentations diminish the single-cycle strength by an amount that increases with increasing indentation load. The critical number of cycles required to cause failure from the indentation flaws is then measured at specified maximum lower surface tensile stresses. At each indentation load, the strength of the ceramic plates diminishes with increased cycling. The scale of degradation is compared with that from previous studies on Y-TZP surfaces containing larger-scale surface damage: sandblast damage, as used in dental crown preparation; and blunt-contact trauma from a spherical indenter at 3000 N. These other damage modes are shown to be equivalent in their strength-degrading capacity to diamond pyramid indentations in the microscale load range 0.1 N to 1 N, attesting to the highly deleterious nature of sharp particulate contacts. The mechanism of fatigue is considered in terms of microcrack evolution within the indentation damage zone.

Senior Health Care System, Meng-Chun Ling

Theses Digitization Project

Senior Health Care System (SHCS) is created for users to enter participants' conditions and store information in a central database. When users are ready for quarterly assessments the system generates a simple summary that can be reviewed, modified, and saved as part of the summary assessments, which are required by Federal and California law.

Population Histories Of Right Whales (Cetacea: Eubalaena) Inferred From Mitochondrial Sequence Diversities And Divergences Of Their Whale Lice (Amphipoda: Cyamus), Zofia A. Kaliszewska, Jon Seger, Victoria J. Rowntree, Amy R. Knowlton, Kim Marshalltilas, Nathalie J. Patenaude, Mariana Rivarola, Catherine M. Schaeff, Mariano Sironi, Wendy A. Smith, Tadasu K. Yamada, Susan G. Barco, Rafael Benegas, Peter B. Best, Moira W. Brown, Robert L. Brownell Jr., Robert Harcourt, Alejandro Carribero

United States Department of Commerce: Staff Publications

Right whales carry large populations of three ‘whale lice’ (Cyamus ovalis, Cyamus gracilis, Cyamus erraticus) that have no other hosts. We used sequence variation in the mitochondrial COI gene to ask (i) whether cyamid population structures might reveal associations among right whale individuals and subpopulations, (ii) whether the divergences of the three nominally conspecific cyamid species on North Atlantic, North Pacific, and southern right whales (Eubalaena glacialis, Eubalaena japonica, Eubalaena australis) might indicate their times of separation, and (iii) whether the shapes of cyamid gene trees might contain information about changes in the population …

Online Project Management System, Amit Dhir

Theses Digitization Project

The purpose of this project is to design and create a system that can be used by a wide variety of groups who do projects. The system created has been specifically tailored for a medium-level company that has employees in different locations and levels, and also has customers for whom they do projects.