Physical Sciences and Mathematics Commons^™

Student Understanding Of Control Of Variables: Deciding Whether Or Not A Variable Influences The Behavior Of A System, Andrew Boudreaux, Peter S. Shaffer, Paula R. L. Heron, Lillian C. Mcdermott

Physics & Astronomy

The ability of adult students to reason on the basis of the control of variables was the subject of an extended investigation. This paper describes the part of the study that focused on the reasoning required to decide whether or not a given variable influences the behavior of a system. The participants were undergraduates taking introductory Physics and K-8 teachers studying physics and physical science in inservice institutes and workshops. Although most of the students recognized the need to control variables, many had significant difficulty with the underlying reasoning. The results indicate serious shortcomings in the preparation of future scientists …

Estimating Live Forest Carbon Dynamics With A Landsat-Based Curve-Fitting Approach, David O. Wallin, Todd A. Schroeder, Andrew N. Gray, Mark E. Harmon, Warren B. Cohen

Environmental Sciences Faculty and Staff Publications

Direct estimation of aboveground biomass with spectral reflectance data has proven challenging for high biomass forests of the Pacific Northwestern United States. We present an alternative modeling strategy which uses Landsat’s spatial, spectral and temporal characteristics to predict live forest carbon through integration of stand age and site index maps and locally calibrated Chapman-Richards curves. Predictions from the curve-fit model were evaluated at the local and landscape scales using two periods of field inventory data. At the pixel-level, the curve-fit model had large positive bias statistics and at the landscape scale over-predicted study area carbon for both inventory periods. Despite …

Finding Nash Equilibria In Two-Player, Zero Sum Games, Jeffrey Wimpee

Computer Science Graduate and Undergraduate Student Scholarship

In many games, it is desirable to find strategies for all players that simultaneously maximize their respective worst-case payoffs. A set of strategies satisfying this criterion is called a Nash equilibrium. Because the search space of possible strategies grows rapidly as the size of the game increases, specialized algorithms are needed to efficiently find Nash equilibria. In this paper, current equilibrium-finding methods are presented and key areas for future work are identified. The first algorithm, due to Koller, Megiddo, and von Stengel, computes standard Nash equilibria in two-player, zero-sum games. The second algorithm, due to Miltersen and Sorensen, extends the …

Machine Vision: A Survey, David Phillips

Computer Science Graduate and Undergraduate Student Scholarship

This paper surveys the field of machine vision from a computer science perspective. It is written to act as an introduction to the field and presents the reader with references to specific implementations. Machine vision is a complex and developing field that can be broken into the three stages: stereo correspondence, scene reconstruction, and object recognition. We present the techniques and general approaches to each of these stages and summarize the future direction of research.

Information Extraction In Text Mining, Matt Mulins

Computer Science Graduate and Undergraduate Student Scholarship

Text mining’s goal, simply put, is to derive information from text. Using multitudes of technologies from overlapping fields like Data Mining and Natural Language Processing we can yield knowledge from our text and facilitate other processing. Information Extraction (IE) plays a large part in text mining when we need to extract this data. In this survey we concern ourselves with general methods borrowed from other fields, with lower-level NLP techniques, IE methods, text representation models, and categorization techniques, and with specific implementations of some of these methods. Finally, with our new understanding of the field we can discuss a proposal …

Developing Web Crawlers For Vertical Search Engines: A Survey Of The Current Research, Pedro Huitema

Computer Science Graduate and Undergraduate Student Scholarship

Vertical search engines allow users to query for information within a subset of documents relevant to a pre-determined topic (Chakrabarti, 1999). One challenging aspect to deploying a vertical search engine is building a Web crawler that distinguishes relevant documents from non-relevant documents. In this research, we describe and analyze various methods to crawl relevant documents for vertical search engines, and we examine ways to apply these methods to building a local search engine. In a typical crawl cycle for a vertical search engine, the crawler grabs a URL from the URL frontier, downloads content from the URL, and determines the …

Combined Object Recognition Approaches For Mobile Robotics, Rusty Gerard

Computer Science Graduate and Undergraduate Student Scholarship

There are numerous solutions to simple object recognition problems when the machine is operating under strict environmental conditions (such as lighting). Object recognition in real-world environments poses greater difficulty however. Ideally mobile robots will function in real-world environments without the aid of fiduciary identifiers. More robust methods are therefore needed to perform object recognition reliably. A combined approach of multiple techniques improves recognition results. Active vision and peripheral-foveal vision—systems that are designed to improve the information gathered for the purposes of object recognition—are examined. In addition to active vision and peripheral-foveal vision, five object recognition methods that either make use …

Connectivity Of A Gaussian Network, Paul Balister, BéLa Bollobás, Amites Sarkar, Mark Walters

Mathematics Faculty Publications

Following Etherington, Hoge and Parkes, we consider a network consisting of (approximately) N transceivers in the plane R² distributed randomly with density given by a Gaussian distribution about the origin, and assume each transceiver can communicate with all other transceivers within distance s. We give bounds for the distance from the origin to the furthest transceiver connected to the origin, and that of the closest transceiver that is not connected to the origin.

Comparison Of Marker-Based Pairwise Relatedness Estimators On A Pedigreed Plant Population, Amy D. Anderson, Marco C.A.M. Bink, W. Eric Van De Weg, Elizabeth A. Thompson

Mathematics Faculty Publications

Several estimators have been proposed that use molecular marker data to infer the degree of relatedness for pairs of individuals. The objective of this study was to evaluate the performance of seven estimators when applied to marker data of a set of 33 key individuals from a large complex apple pedigree. The evaluation considered different scenarios of allele frequencies and different numbers of marker loci. The method of moments estimators were Similarity, Queller-Goodknight, Lynch-Ritland and Wang. The maximum likelihood estimators were Thompson, Anderson-Weir and Jacquard. The pedigree-based coancestry coefficients were taken as the point of reference in calculating correlations and …

Rank Generating Functions As Weakly Holomorphic Modular Forms, Scott Ahlgren, Stephanie Treneer

Mathematics Faculty Publications

Introduction and statement of results. Recent works have illustrated that the Fourier coefficients of harmonic weak Maass forms of weight 1/2 contain a wealth of number-theoretic and combinatorial information. After these works, it is known that many enigmatic q-series (the “mock theta functions” of Ramanujan, and certain rank-generating functions from the theory of partitions, for example) arise naturally as the “holomorphic parts” of such forms. See, for example, Bringmann and Ono [5, 6], Bringmann, Ono, and Rhoades [7], Zwegers [19], Bringmann and Lovejoy [4], Lovejoy and Osburn [12], or see the survey paper [13] for an overview. As another …

The Planet, 2008, Winter, Page A. Buono, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.

Magnetic Fabric Analysis Of Foreslope Sediments Of The Fraser River Delta, British Columbia, Andrew P. (Andrew Paul) Wiser

WWU Graduate School Collection

The results of a combined magnetic fabric and sedimentological investigation of trench and ridge structures along the foreslope of the Fraser Delta, British Columbia, indicate that turbidity currents are the likely origin of slope morphology. Evidence includes multiple and repetitive sequences of graded beds where trench and ridge structures are most pronounced and abundant. Distal to this region are fewer graded bedding sequences and increased evidence of hemipelagic deposition. A magnetic fabric analysis of cored sediments supports these conclusions. Stereographic projections of AMS ellipsoids from graded beds extracted from the mid-slope display characteristic turbidite relationships, whereas distal cores display hemipelagic …

Timing And Nature Of Post-Collapse Sedimentation In Kulshan Caldera, North Cascades, Washington, Dennis M. (Dennis Martin) Feeney

WWU Graduate School Collection

Sedimentary rocks found in the 4.5 x 8 km Kulshan caldera of the Mount Baker volcanic field in the North Cascades, WA, indicate that the post-collapse basin hosted a lacustrine environment shortly after the initial collapse at 1.149 Ma (Hildreth, 1996). The sedimentary rocks of the 14 Goat area in Kulshan caldera are well-preserved in 124 meters of stratigraphic exposure. Blocks of wall rock debris in the lower stratigraphy show instability in the caldera wall. Intermediate and late stages are mainly turbidites composed primarily of sediments derived from extra-caldera ignimbrite. From these 1 interpret the 14 Goat area of Kulshan …

Habitat Relationships And Gene Flow Of Martes Americana In Northern Idaho, Tzeidle N. (Tzeidle Nichole) Wasserman

WWU Graduate School Collection

Forest fragmentation can have a dramatic effect on landscape connectivity and dispersal of animals, potentially reducing gene flow within and among populations. American marten populations (Martes americana) are sensitive to forest fragmentation and the spatial configuration of patches of remnant mature forest has an important impact on habitat quality. This study represents an extensive multiple scale habitat relationships analysis conducted for American marten. In conjunction with Idaho Department of Fish and Game (IDFG) and the U.S. Forest Service, genetic data on marten populations across the Idaho Panhandle National Forest was used to build habitat relationships models. Over 3 years of …

An Investigation Of The Magnetic Fabrics And The Paleomagnetism Of The Ghost Rocks Formation, Kodiak Islands, Alaska, Sean F. Gallen

WWU Graduate School Collection

Recent tectonic models based on the hypothesized existence of the Resurrection plate between the Kula and Farallon plates have questioned the location(s) of trench-ridge-trench (TRT) triple junction(s) along the Northern Cordilleran margin during Paleocene to Eocene time. The Paleocene Ghost Rocks Formation, located in the Kodiak islands, Alaska (latitude ~57°N), consists of pillow lavas and hypabyssal sills interbedded with turbidites, and is interpreted to have formed in a trench slope or slope basin during the passage of a TRT triple junction. A previous paleomagnetic study (Plumley et al., 1983) on the volcanic flows of the Ghost Rocks Formation suggests these …

Revisiting The Seven Devils-Wrangellia Connection: The Paleogeography Of Triassic Rocks In Western Idaho., Michael Liam. Kalk

WWU Graduate School Collection

The origins of and relationships between allochthonous terranes located west of the ⁸⁷Sr/⁸⁶Sr 0.706 line (Armstrong et al., 1977) have profound implications for understanding the Mesozoic paleogeography of western North America. The Wallowa- Seven Devils terrane has long been associated with Wrangellia, whose fragments can now be found in British Columbia, Canada and Alaska. However, stratigraphic, fossil, geochemical, structural, and paleomagnetic evidence linking the Wallowa-Seven Devils terrane to Wrangellia is considered equivocal (Follo, 1992). A new paleomagnetic study of the Seven Devils terrane may yield better results than Hillhouse et al. (1982) and, in conjunction with other …

A Spatially Explicit Relative Elevation Model For Padilla Bay, Washington, Peter Kairis

WWU Graduate School Collection

The dynamics that govern the elevation of a coastal wetland relative to sea level are complex, involving non-linear feedbacks among opposing processes. Changes in the balance between these processes can result in significant alterations to vegetation communities that are adapted to a specific range of water levels. Given that the accretion rate in Padilla Bay, Washington, is suspected to be considerably lower than historical levels and that eustatic sea level rise continues to accelerate, the long term sustainability of the Zostera marina (eelgrass) meadows in the bay may be at risk to eventual submergence. I extended an existing Relative Elevation …

Characterizing Surface Deformation From 1981 To 2007 On Mount Baker Volcano, Washington, Brendan E. Hodge

WWU Graduate School Collection

Surface deformation studies at active volcanoes are used to detect changes to magmatic source regions beneath the volcano. At Mount Baker, Washington, continued elevated gas (CO₂ and H₂S) and heat flux from fumaroles in Sherman Crater indicate the presence of a degassing magma reservoir. Campaign geographic positioning system surveys in 2006 and 2007 provide slope distance measurements of all 19 trilateration lines on Mount Baker. These data are compared with previous slope distance measurements acquired in 1981 and 1983 with electronic distance measurement. The results indicate that surface deformation has occurred on Mount Baker during the last …

Kinematic Analysis Of Ductile Features Within The Northern Wenatchee Block, North Cascades, Washington, Gerald Griesel

WWU Graduate School Collection

The Cascade crystalline core of Washington State is a block of high grade metamorphic and plutonic rocks at the southeast end of the Cretaceous-Tertiary Coast Plutonic Complex. Previous workers have debated whether northwest translation or southwest-vergent thrusting was responsible for regional metamorphism and deformation. The present study finds structural evidence supporting both orogen-normal and orogen-parallel displacements, thus indicating that the regional deformation can be broadly characterized as transpressional.

Units of the study area include: 1) the Napeequa schist, derived from an ocean floor protolith, and 2) an accreted Triassic arc, which includes the Marblemount Meta Quartz-Diorite (MMQD) and metamorphosed volcanic …

Structural Geology Of The Central San Juan Islands, Northwest Washington, Todd I. Belanger

WWU Graduate School Collection

Within the Late Cretaceous San Juan thrust system, northwest Washington, tectonically juxtaposed melange separates the relatively unmetamorphosed, arc-affinity Fidalgo Complex and the high pressure-low temperature, MORB-affmity Ocean Floor terrane. Structural analysis. X-ray diffraction, and fault-slip analysis are used to constrain the relative timing, kinematics, and pressure-temperature conditions of postfabric ductile and brittle deformation in the Fidalgo Complex, Ocean Floor, and melange. Structural analysis of the melange, Fidalgo Complex, and Ocean Floor terranes help to constrain the tectonic development of the structurally highest terranes in the San Juan thrust system and provide insight into the mechanisms required for uplift of high-pressure …

Paleomagnetism And Detrital Zircon Geochronology Of The Skeena Group, British Columbia, Christopher L. Ward-Guthrie

WWU Graduate School Collection

The mid-Cretaceous Skeena Group of British Columbia is a sedimentary continental margin deposit that overlies the lower Jurassic Hazelton Group of the Stikine Terrane. Nine paleomagnetic sites were collected in 2006 and 2007, demagnetized thermally in 50-15°C steps, and high temperature components fit using principal component analysis. A new Ar⁴⁰/Ar³⁹ age of 93.9 ± 0.6 Ma for a flow of the Rocky Ridge Formation was also collected.

Three volcanic sites of the Rocky Ridge Volcanics possess coherent magnetizations, but did not prove useful. Five of six sedimentary sites from the Rocher de Boule and Bulkley Canyon Formations …

Lake Samish Water Monitoring Project 2007 Final Report, Robin A. Matthews, Joan Vandersypen

Lake Samish

This report is a revised version of the 2006 Final Report by Matthews, et al., and contains most of the original text, updated figures, and additional discussion of the new data collected from July 2006 through June 2007.

Lake Samish is a valuable aquatic resource, providing public access for boating, fishing, swimming, picnicking, and other water and lakeshore activities. Residents around the lake enjoy outstanding views of both the lake and its surrounding watershed, and the lake serves as a water supply for many of the lakeshore residents. Lake Samish is located in the Washington State Department of Ecology’s water …

Improved Photometric Calibrations For Red Stars Observed With The Sdss Photometric Telescope, James R. A. Davenport, John J. Bochanski, Kevin R. Covey, Suzanne L. Hawley, Andrew A. West, Doanld P. Schneider

Physics & Astronomy

We present a new set of photometric transformations for red stars observed with the Sloan Digital Sky Survey (SDSS) 0.5 m Photometric Telescope (PT) and the SDSS 2.5 m telescope at the Apache Point Observatory in New Mexico. Nightly PT observations of US Naval Observatory standards are used to determine extinction corrections and calibration terms for SDSS 2.5 m photometry. Systematic differences between the PT and native SDSS 2.5 m ugriz photometry require conversions between the two systems which have previously been undefined for the reddest stars. By matching ~43,000 stars observed with both the PT and SDSS 2.5 m, …

Mapping Russian Forest Biomass With Data From Satellites And Forest Inventories, Richard A. Houghton, David Butman, Andrew Godard Bunn, Olga N. Krankina, Peter Schlesinger, Thomas A. Stone

Environmental Sciences Faculty and Staff Publications

The forests of Russia cover a larger area and hold more carbon than the forests of any other nation and thus have the potential for a major role in global warming. Despite a systematic inventory of these forests, however, estimates of total carbon stocks vary, and spatial variations in the stocks within large aggregated units of land are unknown, thus hampering measurement of sources and sinks of carbon. We mapped the distribution of living forest biomass for the year 2000 by developing a relationship between ground measurements of wood volume at 12 sites throughout the Russian Federation and data from …

Responses Of The Circumpolar Boreal Forest To 20th Century Climate Variability, Andrea H. Lloyd, Andrew Godard Bunn

Environmental Sciences Faculty and Staff Publications

We examined relationships between tree ring-width and climate at 232 sites around the circumpolar boreal forest to explore variability in two types of response to temperature: a browning response characterized by inverse correlations between growth and temperature, and a greening response characterized by positive correlations between growth and temperature. We used moving-window correlation analysis for eight 30-year time windows, lagged by 10 years, to characterize the climate response at each site from 1902 to 2002. Inverse growth responses to temperature were widespread, occurring in all species, all time periods, and in nearly all geographic areas. The frequency of the browning …

The Planet, 2007, Fall, Page A. Buono, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.

Elongation Factor G Stabilizes The Hybrid-State Conformation Of The 70s Ribosome, P. Clint Spiegel, Dmitri N. Ermolenko, Harry F. Noller

Chemistry Faculty and Staff Publications

Following peptide bond formation, transfer RNAs (tRNAs) and messenger RNA (mRNA) are translocated through the ribosome, a process catalyzed by elongation factor EF-G. Here, we have used a combination of chemical footprinting, peptidyl transferase activity assays, and mRNA toeprinting to monitor the effects of EF-G on the positions of tRNA and mRNA relative to the A, P, and E sites of the ribosome in the presence of GTP, GDP, GDPNP, and fusidic acid. Chemical footprinting experiments show that binding of EF-G in the presence of the non-hydrolyzable GTP analog GDPNP or GDP·fusidic acid induces movement of a deacylated tRNA from …

Northern High-Latitude Ecosystems Respond To Climate Change, Andrew Godard Bunn, Scott J. Goetz, John S. Kimball, Ke Zhang

Environmental Sciences Faculty and Staff Publications

The northern high latitudes are an area of particular importance to global climate change. As a system dependent on freezing conditions, the top of the planet contains vast amounts of carbon in biomass, soils, and permafrost that have the potential to interact with the atmosphere through the biosphere, hydrosphere, lithosphere, and cryosphere. If released en masse, this carbon would greatly exacerbate the levels of greenhouse gases in the atmosphere.

Over the past 2 years, a growing body of research has provided evidence of substantial but idiosyncratic environmental changes, with some surprising aspects, across the region. This article reviews some recent …

Linkage Disequilibrium In Wild Mice, Cathy C. Laurie, Deborah A. Nickerson, Amy D. Anderson, Bruce S. Weir, Robert J. Livingston, Matthew D. Dean, Kimberly L. Smith, Eric E. Schadt, Michael W. Nachman

Mathematics Faculty Publications

Crosses between laboratory strains of mice provide a powerful way of detecting quantitative trait loci for complex traits related to human disease. Hundreds of these loci have been detected, but only a small number of the underlying causative genes have been identified. The main difficulty is the extensive linkage disequilibrium (LD) in intercross progeny and the slow process of fine-scale mapping by traditional methods. Recently, new approaches have been introduced, such as association studies with inbred lines and multigenerational crosses. These approaches are very useful for interval reduction, but generally do not provide single-gene resolution because of strong LD extending …

Channel Width Response To Differential Uplift, Colin B. Amos, Douglas W. Burbank

Geology Faculty Publications

The role of channel width and slope adjustments to differential uplift in rivers within actively deforming terrains remains contentious. Here high‐resolution topographic surveying of formerly antecedent outwash channels demonstrates marked changes in channel width as a primary response to differential uplift. For five Late Quaternary alluvial paleochannels crossing small folds along the active Ostler fault zone of southern New Zealand, nearly continuous measurements of paleochannel width and concomitant incision reveal abrupt narrowing of widths toward minimum values at channel positions coincident with the initial uplift. When the magnitude of differential uplift is sufficiently small, narrowing alone permits these channels to …