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2012

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Articles 11881 - 11910 of 12196

Full-Text Articles in Physical Sciences and Mathematics

Salmon In The Trees: An Assessment Of A Dendrochemical Technique For Detecting Marine-Derived Nitrogen In Riparian Tree Rings, Jody Gerdts Jan 2012

Salmon In The Trees: An Assessment Of A Dendrochemical Technique For Detecting Marine-Derived Nitrogen In Riparian Tree Rings, Jody Gerdts

WWU Graduate School Collection

Quantifying the relationship between salmon escapement and riparian tree-ring δ15N could contribute greatly to understanding trends in historic salmon abundance. Such an understanding could have far-reaching consequences for understanding historic carrying capacities of river systems and help guide future restoration efforts. This study investigates the reliability of using naturally occurring isotopic variations in annual tree rings to produce quantifiable estimates of historic salmon runs. Three study areas with temporal and spatial changes in salmon spawning abundance were examined. I found that currently available techniques for removing mobile nitrogen are not sufficient to overcome problems associated with radial mobility, as indicated …

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Block Rotation And Magnetostratigraphy Of The Fish Creek-Vallecito Basin, Salton Trough, Ca, Christopher J. Deboer Jan 2012

Block Rotation And Magnetostratigraphy Of The Fish Creek-Vallecito Basin, Salton Trough, Ca, Christopher J. Deboer

WWU Graduate School Collection

The Fish Creek-Vallecito basin (FCVB) is a large Plio-Pleistocene sedimentary basin in the western Salton Trough, CA. The FCVB formed during subsidence along the West Salton Detachment fault and was uplifted and tilted when slip along the West Salton Detachment fault ended and the region became dominated by strike-slip faulting. This study uses paleomagnetism and magnetostratigraphy to determine the timing and rate of rotation of the FCVB. Two hundred and one sites were sampled in the Palm Spring Group of the FCVB. Magnetite and hematite are identified as carriers of remanence, and rock magnetic measurements are consistent with a magnetite …

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Gis Investigation Of Scarps On Slide Mountain, Western Whatcom County, Washington, Orion George Jan 2012

Gis Investigation Of Scarps On Slide Mountain, Western Whatcom County, Washington, Orion George

WWU Graduate School Collection

Scarps can form from active faulting and landsliding. Such scarps can be difficult to differentiate in mountainous regions before expensive field work is done. Remote techniques to differentiate between scarps can help focus research time and money on active tectonic scarps. This study utilizes high resolution topographic data derived from light detection and ranging (LiDAR) and a geographic information system (GIS) to analyze geomorphometric differences between landslide headscarps and active tectonic scarps in western Washington. The study is separated into two distinct phases, a GIS mapping phase and a GIS geomorphic analysis phase. The GIS mapping phase focused on mapping …

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Magnetic Fabric Analyses Of Ocean Floor Sediments: Characterizing Depositional Processes In The Nankai Trough And Shikoku Basin, Beth Novak Jan 2012

Magnetic Fabric Analyses Of Ocean Floor Sediments: Characterizing Depositional Processes In The Nankai Trough And Shikoku Basin, Beth Novak

WWU Graduate School Collection

Magnetic fabric analysis was conducted on accretionary prism sediments and on sediments taken from the Shikoku Basin during Integrated Ocean Drilling Program (IODP) Expedition (Exp) 333 in order to characterize the sedimentary processes and depositional mechanisms active along the Nankai Trough. Sedimentary ages, in the form of a magnetostratigraphy, were also determined for these sediments during the course of this study. IODP Exp 333 focused coring efforts off the coast of the Kii Peninsula in Japan on three sites, one site within the Nankai Trough accretionary prism (Site C0018) and two sites seaward of the Nankai Trough in the Shikoku …

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Felsic Magmas From Mt. Baker In The Northern Cascade Arc: Origin And Role In Andesite Production, Julie A. (Julie Angela) Gross Jan 2012

Felsic Magmas From Mt. Baker In The Northern Cascade Arc: Origin And Role In Andesite Production, Julie A. (Julie Angela) Gross

WWU Graduate School Collection

Dacitic magmas in volcanic arcs play a critical role in the growth and development of felsic continental crust through mixing to form andesite, or to a lesser extent, by directly adding new crustal material through fractionation of mantle derived basalts. Though dacitic erupted lavas are scarce on Mt. Baker, this study discusses their importance in subsurface processes such as mixing with more mafic magmas, and their potential to add directly to the volume of continental crust. A comprehensive data set (including major, trace, and rare earth element abundances, as well as petrography and mineral chemistry) reveals that the most Sirich, …

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An Analysis Of Agricultural Land-Use Effects On Surface Water Quality In Skagit County Streams, Marysutton Carruthers Jan 2012

An Analysis Of Agricultural Land-Use Effects On Surface Water Quality In Skagit County Streams, Marysutton Carruthers

WWU Graduate School Collection

Nonpoint source pollution is a concern in many streams nationwide. Puget Sound cleanup efforts have increasingly focused on targeting nonpoint sources of pollution, including nutrient and bacterial sources resulting from agricultural activities. Skagit County, Washington hosts a robust compilation of agricultural activities from large scale row crops and dairy operations to small hobby farms. It is also home to the Skagit River, the most important river system for Puget Sound salmon, and Samish Bay, the largest shellfish growing area in the north Puget Sound. Enormous efforts have been made to assess the health of Washington's waterways and to find an …

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Diagenesis Of The Middle Member Of The Bakken Formation, Williston Basin, North Dakota, Katharine L. Kimber Jan 2012

Diagenesis Of The Middle Member Of The Bakken Formation, Williston Basin, North Dakota, Katharine L. Kimber

Theses and Dissertations

The shales of the Bakken Formation have been extensively studied since the discovery of oil, but little attention has been paid to the middle reservoir member. Successfully produced wells are concentrated in multiple fields throughout the Williston Basin, there has been no definitive way to determine a well’s potential productivity. This study used core samples, point counting, and petrography to determine the diagenetic traits common to the Middle Member of the Bakken Formation and their effect on oil production. Cores from forty-one wells were examined. Thin sections were made from sixteen cores, eight producing wells and eight dry wells. All …

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On The Global Stability Of A Generalized Cholera Epidemiological Model, Yuanji Cheng, Jin Wang, Xiuxiang Yang Jan 2012

On The Global Stability Of A Generalized Cholera Epidemiological Model, Yuanji Cheng, Jin Wang, Xiuxiang Yang

Mathematics & Statistics Faculty Publications

In this paper, we conduct a careful global stability analysis for a generalized cholera epidemiological model originally proposed in [J. Wang and S. Liao, A generalized cholera model and epidemic/endemic analysis, J. Biol. Dyn. 6 (2012), pp. 568-589]. Cholera is a water-and food-borne infectious disease whose dynamics are complicated by the multiple interactions between the human host, the pathogen, and the environment. Using the geometric approach, we rigorously prove the endemic global stability for the cholera model in three-dimensional (when the pathogen component is a scalar) and four-dimensional (when the pathogen component is a vector) systems. This work unifies the …

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Probability Of Identification: A Statistical Model For The Validation Of Qualitative Botanical Identification Methods, Robert A. Labudde, James M. Harnly Jan 2012

Probability Of Identification: A Statistical Model For The Validation Of Qualitative Botanical Identification Methods, Robert A. Labudde, James M. Harnly

Mathematics & Statistics Faculty Publications

A qualitative botanical identification method (BIM) is an analytical procedure that returns a binary result (1 = Identified, 0 = Not Identified). A BIM may be used by a buyer, manufacturer, or regulator to determine whether a botanical material being tested is the same as the target (desired) material, or whether it contains excessive nontarget (undesirable) material. The report describes the development and validation of studies for a BIM based on the proportion of replicates identified, or probability of identification (POI), as the basic observed statistic. The statistical procedures proposed for data analysis follow closely those of the probability of …

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A Wealth Of Numbers: An Anthology Of 500 Years Of Popular Mathematics Writing, By Benjamin Wardhaugh. Princeton University Press: Princeton, 2012 (Book Review), John A. Adam Jan 2012

A Wealth Of Numbers: An Anthology Of 500 Years Of Popular Mathematics Writing, By Benjamin Wardhaugh. Princeton University Press: Princeton, 2012 (Book Review), John A. Adam

Mathematics & Statistics Faculty Publications

(First paragraph) To describe the landscape encompassed by this book I can do no better than to quote the dust jacket: "A Wealth of Numbers includes recreational, classroom, and work mathematics; mathematical histories and biographies; accounts of higher mathematics; explanations of mathematical instruments; discussions of how math should be taught and learned; reflections on the place of math in the world; and math in fiction and humor." More such details can be found on the Princeton University Press website. I shall use this as a point of departure to describe the highlights of my own trajectory through the book. Not …

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Fusion Of Visual And Thermal Images Using Genetic Algorithms, Sertan Erkanli, Jiang Li, Ender Oguslu, Shangce Gao (Ed.) Jan 2012

Fusion Of Visual And Thermal Images Using Genetic Algorithms, Sertan Erkanli, Jiang Li, Ender Oguslu, Shangce Gao (Ed.)

Electrical & Computer Engineering Faculty Publications

No abstract provided.

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Sparse Coding For Hyperspectral Images Using Random Dictionary And Soft Thresholding, Ender Oguslu, Khan Iftekharuddin, Jiang Li, Mark Allen Neifeld (Ed.), Amit Ashok (Ed.) Jan 2012

Sparse Coding For Hyperspectral Images Using Random Dictionary And Soft Thresholding, Ender Oguslu, Khan Iftekharuddin, Jiang Li, Mark Allen Neifeld (Ed.), Amit Ashok (Ed.)

Electrical & Computer Engineering Faculty Publications

Many techniques have been recently developed for classification of hyperspectral images (HSI) including support vector machines (SVMs), neural networks and graph-based methods. To achieve good performances for the classification, a good feature representation of the HSI is essential. A great deal of feature extraction algorithms have been developed such as principal component analysis (PCA) and independent component analysis (ICA). Sparse coding has recently shown state-of-the-art performances in many applications including image classification. In this paper, we present a feature extraction method for HSI data motivated by a recently developed sparse coding based image representation technique. Sparse coding consists of a …

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Mathematical Model Development Of Super-Resolution Image Wiener Restoration, Amr H. Yousef, Jiang Li, Mohammad A. Karim Jan 2012

Mathematical Model Development Of Super-Resolution Image Wiener Restoration, Amr H. Yousef, Jiang Li, Mohammad A. Karim

Electrical & Computer Engineering Faculty Publications

In super-resolution (SR), a set of degraded low-resolution (LR) images are used to reconstruct a higher-resolution image that suffers from acquisition degradations. One way to boost SR images visual quality is to use restoration filters to remove reconstructed images artifacts. We propose an efficient method to optimally allocate the LR pixels on the high-resolution grid and introduce a mathematical derivation of a stochastic Wiener filter. It relies on the continuous-discrete-continuous model and is constrained by the periodic and nonperiodic interrelationships between the different frequency components of the proposed SR system. We analyze an end-to-end model and formulate the Wiener filter …

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Green Transportation For A Green Earth, Petros J. Katsioloudis, Mildred V. Jones Jan 2012

Green Transportation For A Green Earth, Petros J. Katsioloudis, Mildred V. Jones

STEMPS Faculty Publications

Transportation is one of the biggest contributors to the destruction of the environment. Results from environmental research and pursuant governmental regulations are changing the way companies do business and how transportation systems address the future. The Environmental Protection Agency (EPA) has been at the forefront in leading environmental research and instituting policies and regulations to fight the issues impacting the environment. The transportation industry and consumers alike are concerned about the environment, energy resources, efficiencies, and economics. In this article, the authors suggest that it is vital that people promote the protection of the environment and strengthen the laws that …

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Tunable Gold Nanostructures With Nanocapsules As Template Reaction Vessels, Balasubramanian Ramjee, Srujana Prayakarao, Sangbum Han, Wei Cao Jan 2012

Tunable Gold Nanostructures With Nanocapsules As Template Reaction Vessels, Balasubramanian Ramjee, Srujana Prayakarao, Sangbum Han, Wei Cao

Chemistry & Biochemistry Faculty Publications

Hollow, polymeric, thiol-ene resorcinarene nanocapsules can act as template reaction vessels for the synthesis of gold nanoshells or spherical aggregates of gold nanoparticles depending on the reaction conditions. The spherical nanoparticle aggregates were evaluated as catalysts in the biphasic reduction of 4-nitrophenol.

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The Management Of Feral Pig Socio-Ecological Systems In Far North Queensland, Australia, Gabriela Shuster Jan 2012

The Management Of Feral Pig Socio-Ecological Systems In Far North Queensland, Australia, Gabriela Shuster

Antioch University Dissertations & Theses

The development of management programs for socio-ecological systems that include multiple stakeholders is a complex process and requires careful evaluation and planning. This is particularly a challenge in the presence of intractable conflict. The feral pig (Sus scrofa) in Australia is part of one such socio-ecological system. There is a large and heterogeneous group of stakeholders interested in pig management. Pigs have diverse effects on wildlife and plant ecology, economic, health, and social sectors. This study used the feral pig management system as a vehicle to examine intractable conflict in socio-ecological systems. The purpose of the study was …

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The Effect Of Disinfectants, Cleaning, And Drying Practices On Oriental Rugs Flooded With Contaminated River Water: Public Health And Policy Implications, Daniel Bernazzani Jan 2012

The Effect Of Disinfectants, Cleaning, And Drying Practices On Oriental Rugs Flooded With Contaminated River Water: Public Health And Policy Implications, Daniel Bernazzani

Antioch University Dissertations & Theses

Oriental rugs contaminated with Category 3 floodwater potentially harbor environmental bacteria known to be human pathogens. River water inoculated with three species of gram positive and gram negative environmental bacteria (Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa) were used to assess the effectiveness of disinfectant type, cleaning methodology and drying practices by examining the survival rates of bacteria. Rug sections were immersed for one hour in contaminated water, saturated in one of three EPA registered disinfectant products (Phenol, Quaternary chloride, and Thyme oil) or tap water as a control, followed by cleaning and drying. The results showed that all disinfectants reduced …

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Explainers' Development Of Science-Learner Identities Through Participation In A Community Of Practice, Anne E. Richardson Jan 2012

Explainers' Development Of Science-Learner Identities Through Participation In A Community Of Practice, Anne E. Richardson

Antioch University Dissertations & Theses

The urgent environmental issues of today require science-literate adults to engage in business and political decisions to create solutions. Despite the need, few adults have the knowledge and skills of science literacy. This doctoral dissertation is an analytical case study examining the science-learner identity development of Exploratorium Field Trip Explainers. Located in San Francisco, CA, the Exploratorium is a museum of science, art, and human perception dedicated to nurturing curiosity and exploration. Data collected included semi-structured interviews with sixteen former Field Trip Explainers, participant observation of the current Field Trip Explainer Program, and review of relevant documentation. Data analysis employed …

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Shaping The Future Past: Finding History, Creating Identity In The Kwan Hsu Papers, Lisa Chere' Donnelly Jan 2012

Shaping The Future Past: Finding History, Creating Identity In The Kwan Hsu Papers, Lisa Chere' Donnelly

Dissertations and Theses

Dr. Kwan Hsu was neither a superstar nor a celebrity. Her name does not come up in conversations about important contributors to her field of biophysics nor is she instantly recognizable for her contributions to Portland State University's international program or the state of Oregon's business ties with China. Yet she was a contributor, a cog-in-the-wheel, at the very least, in all of these areas and more. She was a peripheral member of a well-known Chinese family, but few in the United States know of or perhaps have interest in, but otherwise, she had no great connections or family ties …

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Evolved Design Of A Nonlinear Proportional Integral Derivative (Npid) Controller, Shubham Chopra Jan 2012

Evolved Design Of A Nonlinear Proportional Integral Derivative (Npid) Controller, Shubham Chopra

Dissertations and Theses

This research presents a solution to the problem of tuning a PID controller for a nonlinear system. Many systems in industrial applications use a PID controller to control a plant or the process. Conventional PID controllers work in linear systems but are less effective when the plant or the process is nonlinear because PID controllers cannot adapt the gain parameters as needed. In this research we design a Nonlinear PID (NPID) controller using a fuzzy logic system based on the Mamdani type Fuzzy Inference System to control three different DC motor systems. This fuzzy system is responsible for adapting the …

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Community Earth System Model: Implementation, Validation, And Applications, William Christian Porter Jan 2012

Community Earth System Model: Implementation, Validation, And Applications, William Christian Porter

Dissertations and Theses

The Community Earth System Model (CESM) is a coupling of five different models which are combined to simulate the dynamic interactions between and within the Earth's atmosphere, ocean, land, land-ice, and sea-ice. In this work, the installation and testing of CESM on Portland State University's Cluster for Climate Change and Aerosol Research (CsAR) is described and documented, and two research applications of the model are performed. First, the improved treatment of cloud microphysics within recent versions of CESM's atmospheric module is applied to an examination of changes in shortwave cloud forcing (SWCF) and results are compared to output from older …

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Development And Implementation Of Acoustic Feedback Control For Scanning Probe Microscopy, Rodolfo Fernandez Rodriguez Jan 2012

Development And Implementation Of Acoustic Feedback Control For Scanning Probe Microscopy, Rodolfo Fernandez Rodriguez

Dissertations and Theses

A remote-sensing acoustic method for implementing position control feedback in Scanning Probe Microscopy (SPM) is presented. The capabilities of this feedback control using the new Whispering Gallery Acoustic Sensing (WGAS) method is demonstrated in a Shear-force Scanning Probe Microscope that uses a sharp probe attached to a piezoelectric Quartz Tuning Fork (QTF) firmly mounted on the microscope's frame. As the QTF is electrically driven its mechanical response reaches the SPM frame which then acts as a resonant cavity producing acoustic modes measured with an acoustic sensor strategically placed on the SPM head. The novelty of the WGAS resides in using …

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A Systems Approach To Ecological Economic Models Developed Progressively In Three Interwoven Articles, Takuro Uehara Jan 2012

A Systems Approach To Ecological Economic Models Developed Progressively In Three Interwoven Articles, Takuro Uehara

Dissertations and Theses

My dissertation develops and analyzes ecological economic models to study the complex dynamics of an ecological economic system (EES) and investigate various conditions and measures which can sustain a developing economy over the long term in view of resilience and sustainability. Because of the intrinsic complexity of the system, I take a systems approach, using economics as the foundation for the basic structure of an ecological economic model, and system dynamics as the method to build and analyze such a complex ecological economic model. Throughout my dissertation, the model developed by Brander and Taylor (1998) is adopted as a baseline …

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Climate Change Effects And Water Vulnerability In The Molalla Pudding River Basin, Oregon, Usa, Susan Amelia Wherry Jan 2012

Climate Change Effects And Water Vulnerability In The Molalla Pudding River Basin, Oregon, Usa, Susan Amelia Wherry

Dissertations and Theses

Water management plans are typically developed using historical data records and historical return periods for extreme events, such as floods or droughts. Since these analyses of return periods typically assume a certain degree of stationarity (constant mean, standard deviation, distribution) in hydrologic variables, the potential future impacts of climate change are excluded. In developing water management plans, predicted changes to climate variables should be considered to evaluate the degree of non-stationarity that may exist in the future. In this way, regions most sensitive to climate change can be identified and managed appropriately. This study performed such a task by using …

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Late Pleistocene And Holocene Aged Glacial And Climatic Reconstructions In The Goat Rocks Wilderness, Washington, United States, Joshua Andrews Heard Jan 2012

Late Pleistocene And Holocene Aged Glacial And Climatic Reconstructions In The Goat Rocks Wilderness, Washington, United States, Joshua Andrews Heard

Dissertations and Theses

Eight glaciers, covering an area of 1.63 km2, reside on the northern and northeastern slopes of the Goat Rocks tallest peaks in the Cascades of central Washington. At least three glacial stands occurred downstream from these glaciers. Closest to modern glacier termini are Little Ice Age (LIA) moraines that were deposited between 1870 and 1899 AD, according to the lichenometric analysis. They are characterized by sharp, minimally eroded crests, little to no soil cover, and minimal vegetation cover. Glacier reconstructions indicate that LIA glaciers covered 8.29 km2, 76% more area than modern ice coverage. The average LIA equilibrium line altitude …

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Scale Invariant Object Recognition Using Cortical Computational Models And A Robotic Platform, Danny Voils Jan 2012

Scale Invariant Object Recognition Using Cortical Computational Models And A Robotic Platform, Danny Voils

Dissertations and Theses

This paper proposes an end-to-end, scale invariant, visual object recognition system, composed of computational components that mimic the cortex in the brain. The system uses a two stage process. The first stage is a filter that extracts scale invariant features from the visual field. The second stage uses inference based spacio-temporal analysis of these features to identify objects in the visual field. The proposed model combines Numenta's Hierarchical Temporal Memory (HTM), with HMAX developed by MIT's Brain and Cognitive Science Department. While these two biologically inspired paradigms are based on what is known about the visual cortex, HTM and HMAX …

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Fundamental Properties Of Functional Zinc Oxide Nanowires Obtained By Electrochemical Method And Their Device Applications, Athavan Nadarajah Jan 2012

Fundamental Properties Of Functional Zinc Oxide Nanowires Obtained By Electrochemical Method And Their Device Applications, Athavan Nadarajah

Dissertations and Theses

We report on the fundamental properties and device applications of semiconductor nanoparticles. ZnO nanowires and CdSe quantum dots were used, prepared, characterized, and assembled into novel light-emitting diodes and solar cells. ZnO nanowire films were grown electrochemically using aqueous soluble chloride-based electrolytes as precursors at temperatures below 90° C. Dopants were added to the electrolyte in the form of chloride compounds, which are AlCl3, CoCl2, CuCl2, and MnCl2. The optical, magnetic, and structural properties of undoped and transition-metal-ion doped ZnO nanowires were explored. Our results indicate that the as-grown nanowire structures have …

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An Introduction To Modern Cryptology Within An Algebraic Framework, John Szwast Jan 2012

An Introduction To Modern Cryptology Within An Algebraic Framework, John Szwast

EWU Masters Thesis Collection

No abstract provided.

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Quadratic And Cubic Reciprocity, Suzanne Rousseau Jan 2012

Quadratic And Cubic Reciprocity, Suzanne Rousseau

EWU Masters Thesis Collection

"In this thesis, we seek to prove results about quadratic and cubic reciprocity in great detail. Although these results appear in many textbooks, the proofs often contain large gaps that may be difficult for the average reader to follow. To achieve this goal, we have 'built up to reciprocity theory from basic principles of algebra, and whenever possible, we have tried to prove the number theoretic results of reciprocity using ideas from group theory. This thesis could potentially serve as a reference for a student who desires to study quadratic or cubic reciprocity in more detail, or as a foundation …

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Ssvep-Based Brain Computer Interface Using The Emotiv Epoc, Brian J. Zier Jan 2012

Ssvep-Based Brain Computer Interface Using The Emotiv Epoc, Brian J. Zier

EWU Masters Thesis Collection

No abstract provided.

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