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Articles 2761 - 2790 of 24230

Full-Text Articles in Physical Sciences and Mathematics

Individual Based Model To Simulate The Evolution Of Insecticide Resistance, William B. Jamieson Dec 2019

Individual Based Model To Simulate The Evolution Of Insecticide Resistance, William B. Jamieson

Department of Mathematics: Dissertations, Theses, and Student Research

Insecticides play a critical role in agricultural productivity. However, insecticides impose selective pressures on insect populations, so the Darwinian principles of natural selection predict that resistance to the insecticide is likely to form in the insect populations. Insecticide resistance, in turn, severely reduces the utility of the insecticides being used. Thus there is a strong economic incentive to reduce the rate of resistance evolution. Moreover, resistance evolution represents an example of evolution under novel selective pressures, so its study contributes to the fundamental understanding of evolutionary theory.

Insecticide resistance often represents a complex interplay of multiple fitness trade-offs for individual …


Advanced Security Analysis For Emergent Software Platforms, Mohannad Alhanahnah Dec 2019

Advanced Security Analysis For Emergent Software Platforms, Mohannad Alhanahnah

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Emergent software ecosystems, boomed by the advent of smartphones and the Internet of Things (IoT) platforms, are perpetually sophisticated, deployed into highly dynamic environments, and facilitating interactions across heterogeneous domains. Accordingly, assessing the security thereof is a pressing need, yet requires high levels of scalability and reliability to handle the dynamism involved in such volatile ecosystems.

This dissertation seeks to enhance conventional security detection methods to cope with the emergent features of contemporary software ecosystems. In particular, it analyzes the security of Android and IoT ecosystems by developing rigorous vulnerability detection methods. A critical aspect of this work is the …


Search For Low-Mass Quark-Antiquark Resonances Produced In Association With A Photon At √S =13 Tev, A. M. Sirunyan Dec 2019

Search For Low-Mass Quark-Antiquark Resonances Produced In Association With A Photon At √S =13 Tev, A. M. Sirunyan

Department of Physics and Astronomy: Faculty Publications

A search for narrow low-mass resonances decaying to quark-antiquark pairs is presented. The search is based on proton-proton collision events collected at 13 TeV by the CMS detector at the CERN LHC. The data sample corresponds to an integrated luminosity of 35.9 fb−1, recorded in 2016. The search considers the case where the resonance has high transverse momentum due to initial-state radiation of a hard photon. To study this process, the decay products of the resonance are reconstructed as a single large-radius jet with two-pronged substructure. The signal would be identified as a localized excess in the jet …


Examining The Effects Of Greenland Ice Sheet Melting And Atlantic Meridional Shutdown On The Climate Of Scandinavia And The British Isles, Tyler Lemburg Dec 2019

Examining The Effects Of Greenland Ice Sheet Melting And Atlantic Meridional Shutdown On The Climate Of Scandinavia And The British Isles, Tyler Lemburg

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Earth’s climate has been rapidly changing over the last hundred years, and its global average temperature is rising. However, climate change is far more complicated than a simple increase in temperature. For example, it is theorized that certain regions of Earth, including Scandinavia and the British Isles, could actually become cooler through ongoing climate change processes. Two of these processes are Greenland Ice Sheet (GrIS) melting, and slowdown of the Atlantic Meridional Overturning Circulation (AMOC). This research examines if climate change, through GrIS melting and AMOC slowdown, could contribute to cooler, instead of warmer, temperatures in Scandinavia and the British …


Modeling Waterfowl Hunter And Ducks Unlimited Member Behavior Using Mark-Recapture Methods, Katherine Graham Dec 2019

Modeling Waterfowl Hunter And Ducks Unlimited Member Behavior Using Mark-Recapture Methods, Katherine Graham

School of Natural Resources: Dissertations, Theses, and Student Research

The number of individuals actively participating in waterfowl hunting has substantially declined since the 1980s, despite relatively abundant waterfowl populations and hunting opportunities. To avoid further losses in political support for wildlife management, losses in habitat conservation revenue, and broaden the base of waterfowl and wetland conservation support, there has been an increased focus on growing the number of waterfowl hunters and waterfowl and wetland conservation supporters. The purpose of this study was to estimate resident waterfowl hunter and Ducks Unlimited (DU) member recruitment rates, retention probabilities, and license/membership purchase probabilities; provide a better understanding of the factors influencing these …


Modeling Elementary Students’ Ideas About Heredity: A Comparison Of Curricular Interventions, Cory Forbes, Dante Cisterna, Devarati Bhattacharya, Ranu Roy Dec 2019

Modeling Elementary Students’ Ideas About Heredity: A Comparison Of Curricular Interventions, Cory Forbes, Dante Cisterna, Devarati Bhattacharya, Ranu Roy

School of Natural Resources: Faculty Publications

Learning about heredity is important across the K–12 continuum. However, these ideas may be challenging for students. We examined third-grade students’ ideas about heredity in the context of a new, six-week, model-based science unit that uses corn as a model organism to support students’ ideas about heredity. We analyzed data collected during implementation of the unit, including student artifacts and interviews. We compared these data to those from a pilot version of the curriculum – implemented in the prior year – that was focused on the same disciplinary concepts but was not designed around scientific modeling. Our findings illustrate levels …


Natural Resource Condition Assessment, Homestead National Monument Of America, David S. Jones, Roy Cook, John Sovell, Christopher Herron, Jay Benner, Karin Decker, Andrew Beavers, Johannes Beebee, David Weinzimmer Dec 2019

Natural Resource Condition Assessment, Homestead National Monument Of America, David S. Jones, Roy Cook, John Sovell, Christopher Herron, Jay Benner, Karin Decker, Andrew Beavers, Johannes Beebee, David Weinzimmer

United States National Park Service: Publications

Executive Summary

The National Park Service (NPS) Natural Resource Condition Assessment (NRCA) Program administered by the NPS Water Resources Division evaluates current conditions for important natural resources and resource indicators using primarily existing information and data. NRCAs also report on trends in resource condition when possible, identify critical data gaps, and characterize a general level of confidence for study findings. This NRCA complements historic resource assessments, is multi-disciplinary in scope, employs a hierarchical indicator framework, identifies and develops reference conditions/values for comparison against current conditions, and emphasizes spatial evaluation of conditions and GIS (map) products.

Congress established the Homestead National …


Plant Community Composition And Structure Monitoring At Wind Cave National Park, 2019 Data Report, Theresa L. Schaffner, Daniel J. Swanson, Stephanie L. Rockwood Dec 2019

Plant Community Composition And Structure Monitoring At Wind Cave National Park, 2019 Data Report, Theresa L. Schaffner, Daniel J. Swanson, Stephanie L. Rockwood

United States National Park Service: Publications

Abstract

This report presents the results of the Northern Great Plains Inventory and Monitoring Network (NGPN) and Northern Great Plains Fire Ecology Program (NGPFire) vegetation monitoring at Wind Cave National Park (WICA) in 2019. This was the ninth year of combined monitoring efforts.

Crew members from NGPN visited 18 long-term monitoring plots to collect data representing the plant communities at WICA. The NGPFire program collected pre- and post-burn data from an additional 37 plant community and forest structure monitoring plots. This work is part of a long-term monitoring effort designed to evaluate the condition of the vegetation community and understand …


Plant Community Composition And Structure Monitoring At Agate Fossil Beds National Monument, 2019 Data Report, Molly B. Davis Dec 2019

Plant Community Composition And Structure Monitoring At Agate Fossil Beds National Monument, 2019 Data Report, Molly B. Davis

United States National Park Service: Publications

Abstract

This report presents the results of vegetation monitoring efforts in 2019 at Agate Fossil Beds National Monument (AGFO) by the Northern Great Plains Inventory and Monitoring Network (NGPN) and the Northern Great Plains Fire Ecology Program (NGPFire). This was the ninth year of combined monitoring efforts.

In 2019, crew members from NGPN visited 6 long-term plant community monitoring (PCM) plots to collect data on the upland mixed-grass prairie plant communities at AGFO. This work is part of a long-term monitoring program established to better understand the condition of the vegetation community and how it changes over time. NGPN staff …


Small Ruminant Health Intervention Calendar In Ethiopia, Mesfin Mekonnen, Ayalew Assefa, Tesfalem Nane, Firdawok Ayele, Asrat Arke, Belay Elias, Barbara Wieland Dec 2019

Small Ruminant Health Intervention Calendar In Ethiopia, Mesfin Mekonnen, Ayalew Assefa, Tesfalem Nane, Firdawok Ayele, Asrat Arke, Belay Elias, Barbara Wieland

Daugherty Water for Food Global Institute: Faculty Publications

Contents

1 Background................................................................................................... 3
2 Developing the health intervention calendar............................................................ 4
The treatment calendar ......................................................... 4 Applying the calendar..................................................................... 5 4 References................................................................... 8


Hunters And Their Perceptions Of Public Access: A View From Afield, Joseph J. Fontaine, Alexis D. Fedele, Lyndsie S. Wszola, Lindsey N. Messinger, Christopher J. Chizinski, Jeffery J. Lusk, Karie L. Decker, J. Scott Taylor, Erica F. Stuber Dec 2019

Hunters And Their Perceptions Of Public Access: A View From Afield, Joseph J. Fontaine, Alexis D. Fedele, Lyndsie S. Wszola, Lindsey N. Messinger, Christopher J. Chizinski, Jeffery J. Lusk, Karie L. Decker, J. Scott Taylor, Erica F. Stuber

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Declining hunter participation threatens cultural traditions and public support for conservation, warranting examination of the forces behind the downward trajectory. Access to lands for hunting, an often-cited reason for non participation, may play a critical role in the retention and recruitment of hunters. Meeting the access needs of a diverse hunting constituency requires understanding how hunters use and perceive access opportunities, particularly public-access sites. Given that perceptions of access are entirely place based and degrade with time, traditional postseason survey methods may fail to adequately quantify the value of public access to the hunting constituency. To overcome the potential limitations …


Final Thoughts As Editor-In-Chief, Christopher N. Jacques Dec 2019

Final Thoughts As Editor-In-Chief, Christopher N. Jacques

The Prairie Naturalist

Greetings GPNSS members! I write this editorial during a time of reflection as Editor-in-Chief of The Prairie Naturalist (TPN), and during unprecedented times as the global COVID-19 pandemic continues. In full disclosure, I do not have a particular topic for this editorial, other than to offer a few final thoughts as my time serving the Great Plains Natural Science Society and TPN.


Bats Of The Loess Hills Ecoregion Of Southeast Nebraska, Virgil Brack Jr, Dale W. Sparks, Darwin C. Brack Dec 2019

Bats Of The Loess Hills Ecoregion Of Southeast Nebraska, Virgil Brack Jr, Dale W. Sparks, Darwin C. Brack

The Prairie Naturalist

We surveyed bats at 49 sites in the Loess Hills Ecoregion of southeastern Nebraska, along the western edge of the eastern forest biome in eastern Richardson, Nemaha, and Otoe counties. We completed this study shortly before the northern long-eared bat (Myotis septentrionalis) was listed by the United States Fish and Wildlife Service under the Endangered Species Act. The expectation of listing, along with potential presence of the endangered Indiana bat (Myotis sodalis), motivated the study. We captured 183 bats of five species: eastern red bat (Lasiurus borealis) (n = 103; 56 %), big brown …


The Prairie Naturalist, Vol. 51, Issue 2, December 2019 Dec 2019

The Prairie Naturalist, Vol. 51, Issue 2, December 2019

The Prairie Naturalist

45 EDITOR’S NOTE: Final Thoughts as Editor-in-Chief, by Christopher N. Jacques

RESEARCH ARTICLES

47 Bats of the Loess Hills Ecoregion of Southeast Nebraska, by Virgil Brack, Jr., Dale W. Sparks, and Darwin C. Brack

58 Serological Survey and Pathogen Exposure of Adult Female White-tailed Deer in the Western Dakotas, by Katherine L. Moratz, Bailey S. Gullikson, Eric S. Michel, Daniel M. Grove, Jonathan A. Jenks, and William F. Jensen

68 Factors Limting Reintroduced Plains Topminnow, Fundulus sciadicus, Populations in Central Great Plains Streams, by Joseph D. Thiessen, Keith D. Koupal, and Casey W. Schoenebeck

NOTES

77 Recent Observations of Water …


Serological Survey And Pathogen Exposure Of Adult Female White-Tailed Deer In The Western Dakotas, Katherine L. Moratz, Bailey S. Gullikson, Eric S. Michel, Daniel M. Grove, Jonathan A. Jenks, William Jensen Dec 2019

Serological Survey And Pathogen Exposure Of Adult Female White-Tailed Deer In The Western Dakotas, Katherine L. Moratz, Bailey S. Gullikson, Eric S. Michel, Daniel M. Grove, Jonathan A. Jenks, William Jensen

The Prairie Naturalist

Establishing baseline values for pathogen exposure and nutritional indices is necessary to monitor population health. However, little is known about white-tailed deer (Odocoileus virginianus) pathogen exposure and nutritional condition in the Northern Great Plains. Our objective was to assess pathogen exposure and establish nutritional indices for female white-tailed deer in Dunn and Grant counties, North Dakota and Perkins County, South Dakota. During 2014, we collected blood serum from 150 adult female white-tailed deer. Pathogens with the highest antibody prevalence included West Nile Virus (WNV; 85%), epizootic hemorrhagic disease (48%), and malignant catarrhal fever (32%). Serum values for creatine …


Recent Observations Of Water Shrews In Northeastern South Dakota, Dennis Skadsen, Robert M. Timm Dec 2019

Recent Observations Of Water Shrews In Northeastern South Dakota, Dennis Skadsen, Robert M. Timm

The Prairie Naturalist

North American water shrews in the genus Sorex are a complex of at least five species, three of which were recognized historically, Sorex alasksans, S. bendirii, and S. palustris (Hall 1981). Within what was previously considered the single, widespread northern species, S. palustris, two additional species are now recognized, S. albibarbis in the eastern US and Canada and S. navigator in the western United States and Canada (Hope et al. 2014; Nagorsen et al. 2017; Woodman 2018). The American water shrew (Sorex palustris) originally was documented in South Dakota by three females, two were collected 1876 and …


Factors Limiting Reintroduced Plains Topminnow, Fundulus Sciadicus, Populations In Central Great Plains Streams, Joseph Thiessen, Keith D. Koupal, Casey W. Schoenebeck Dec 2019

Factors Limiting Reintroduced Plains Topminnow, Fundulus Sciadicus, Populations In Central Great Plains Streams, Joseph Thiessen, Keith D. Koupal, Casey W. Schoenebeck

The Prairie Naturalist

The plains topminnow (Fundulus sciadicus) is an endemic Great Plains stream fish that has experienced declines in geographic range and local abundance. Due to these declines, the species has been considered for federal protection and designated with conservation status in states throughout its historic range. The reasons for declines are likely similar to hypothesized factors for other endemic stream fish declines in the Great Plains. To investigate potential limiting factors a suite of 17 historic sites with reintroduced plains topminnow populations across Nebraska were evaluated for current populations and if plains topminnow were absent, additional fish were introduced. …


Vegetation Classification And Mapping, Missouri National Recreational River, Tom Baldvins, Matt Ley, David Jones, Joe Stevens, Hannah Pilkington Dec 2019

Vegetation Classification And Mapping, Missouri National Recreational River, Tom Baldvins, Matt Ley, David Jones, Joe Stevens, Hannah Pilkington

United States National Park Service: Publications

Executive Summary

The vegetation inventory project at Missouri National Recreational River (MNRR) classified and mapped vegetation within the park administrative boundary and estimated thematic map accuracy quantitatively. The project was conducted over a four year period from the summer of 2015 to the winter of 2019.

The project follows guidance provided by the National Park Service (NPS) Vegetation Mapping Inventory (VMI) Program. The overall process includes initial planning and scoping, imagery procurement, field data collection, data analysis, imagery interpretation and classification, and accuracy assessment. The initial planning and scoping meetings to support study plan development took place in December, 2009, …


Use Of Uav Imagery And Nutrient Analyses For Estimation Of The Spatial And Temporal Contributions Of Cattle Dung To Nutrient Cycling In Grazed Ecosystems, Amanda Shine Dec 2019

Use Of Uav Imagery And Nutrient Analyses For Estimation Of The Spatial And Temporal Contributions Of Cattle Dung To Nutrient Cycling In Grazed Ecosystems, Amanda Shine

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nutrient inputs from cattle dung are crucial drivers of nutrient cycling processes in grazed ecosystems. These inputs are important both spatially and temporally and are affected by variables such as grazing strategy, water location, and the nutritional profile of forage being grazed. Past research has attempted to map dung deposition patterns in order to more accurately estimate nutrient input, but the large spatial extent of a typical pasture and the tedious nature of identifying and mapping individual dung pats has prohibited the development of a time- and cost-effective methodology. The first objective of this research was to develop and validate …


Evidence Of Limited Recruitment Of Pallid Sturgeon In The Lower Missouri River, Kirk D. Steffensen, Kimberly Chojnacki, Jeffrey A. Kalie, Meredith L. Bartron, Edward J. Heist, Kyle R. Winders, Nathan C. Loecker, Wyatt J. Doyle, Timothy L. Welker Dec 2019

Evidence Of Limited Recruitment Of Pallid Sturgeon In The Lower Missouri River, Kirk D. Steffensen, Kimberly Chojnacki, Jeffrey A. Kalie, Meredith L. Bartron, Edward J. Heist, Kyle R. Winders, Nathan C. Loecker, Wyatt J. Doyle, Timothy L. Welker

United States Geological Survey: Staff Publications

Pallid Sturgeon Scaphirhynchus albus are endemic to the Missouri and Mississippi river basins and are rare throughout their range. The species was listed as federally endangered with little to no evidence of natural recruitment. Since population augmentation was initiated as a recovery objective in the early 1990s, thousands of hatchery-origin Pallid Sturgeon have been stocked in the lower Missouri River (Gavins Point Dam [river kilometer 1,305.1] to the confluence of the Mississippi River [river kilometer 0.0]). Efforts to discriminate natural reproduction and recruitment of wild-origin Pallid Sturgeon from hatchery-origin fish has been hampered by tag loss in hatchery-origin sturgeon, inconsistent …


Review Of Sky Dance Of The Woodcock: The Habits And Habitats Of A Strange Little Bird, By Greg Hoch, David E. Andersen Dec 2019

Review Of Sky Dance Of The Woodcock: The Habits And Habitats Of A Strange Little Bird, By Greg Hoch, David E. Andersen

The Prairie Naturalist

American Woodcock (Scolopax minor) have enthralled conservationists (including Aldo Leopold), bird watchers, wildlife enthusiasts, hunters, and others interested in the natural world for centuries. No doubt, woodcock also have enthralled humans in North America for millennia prior to written descriptions of the woodcock’s courtship displays, habitat preferences, and curious behavior and anatomy. As perhaps the most extensively studied species of shorebird in the world, there is a rich and extensive literature, both scientific and popular, focused on woodcock ecology, behavior, and hunting. To that extensive body of literature, Sky Dance of the Woodcock provides an updated summary of …


Review Of Grasslands And Climate Change By David J. Gibson And Jonathan A. Newman, Neal D. Noemuth Dec 2019

Review Of Grasslands And Climate Change By David J. Gibson And Jonathan A. Newman, Neal D. Noemuth

The Prairie Naturalist

The last decade has seen an explosion of information about climate change, some of which is contradictory, much of which is confusing, and the entirety of which is too much for the typical biologist or scientist to assemble and comprehend. This is why reviews such as Grasslands and Climate Change, edited by David Gibson and Jonathan Newman, are so valuable. To produce this review of climate change issues and influences relative to grasslands, Gibson and Newman recruited 30 scientists—predominantly from Europe and North America—who wrote 19 chapters dealing with various aspects of grasslands and climate change. The chapters are grouped …


Umphlett Qci Dec 2019, Natalie A. Umphlett Dec 2019

Umphlett Qci Dec 2019, Natalie A. Umphlett

High Plains Regional Climate Center: Personnel Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Soil Moisture Conditions

Agriculture

Energy

Infrastructure

Temperature

Precipitation


Benchmarking On-Farm Maize Nitrogen Balance In The Western U.S. Corn Belt, Fatima Amor Tenorio Dec 2019

Benchmarking On-Farm Maize Nitrogen Balance In The Western U.S. Corn Belt, Fatima Amor Tenorio

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

A nitrogen (N) balance, calculated as the difference between N inputs and grain-N removal, provides an estimate of the potential N losses. We used N balance with other N-related metrics (partial factor productivity for N inputs, and yield-scaled N balance), to benchmark maize yields in relation with N input use in the US Corn Belt. We first used experimental data on grain-N concentration (GNC) to assess variation in this parameter due to biophysical and management factors. Subsequently, we used N balance and N-related metrics to benchmark yields in relation with N inputs in irrigated and rainfed fields in Nebraska using …


Measurement Of The Production Cross Section Of Four Top Quarks In Proton-Proton Collisions At 13 Tev, Caleb Fangmeier Dec 2019

Measurement Of The Production Cross Section Of Four Top Quarks In Proton-Proton Collisions At 13 Tev, Caleb Fangmeier

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

The field of particle physics involves not only searches for new particles and measurements of their interactions, but also the design and construction of advanced particle detectors. This thesis presents the measurement of the production cross section of four top quarks in proton-proton collisions at a center-of-mass energy of 13 TeV using 137 fb$^{-1}$ of integrated luminosity recorded by the CMS experiment at the LHC. This analysis considers events in the final state of a same-sign pair of leptons, notable for being a final state with relatively few Standard Model background events. A boosted decision tree is utilized to discriminate …


Improvement For Generating High-Order Harmonics And Attosecond Pulses With Ultrashort Laser Fields, Dian Peng Dec 2019

Improvement For Generating High-Order Harmonics And Attosecond Pulses With Ultrashort Laser Fields, Dian Peng

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Nonlinear processes of high-order harmonic generation (HHG) produced by ultrashort few-cycle laser pulses possess interesting features which HHG produced by long pulses of many cycles may not have. First, HHG spectra produced by ultrashort pulses are extremely sensitive to the driving pulse waveform, which can be controlled by laser parameters such as carrier-envelope phases (CEPs), time delays or frequency chirps. Second, HHG spectra produced by ultrashort pulses can exhibit broad uneven peaks which are different from usual odd-ordered harmonic peaks that long pulses produce.

Based on the high sensitivity on pulse waveform of HHG spectra produced by ultrashort pulses, we …


Formal Modeling And Analysis Of A Family Of Surgical Robots, Niloofar Mansoor Dec 2019

Formal Modeling And Analysis Of A Family Of Surgical Robots, Niloofar Mansoor

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Safety-critical applications often use dependability cases to validate that specified properties are invariant, or to demonstrate a counterexample showing how that property might be violated. However, most dependability cases are written with a single product in mind. At the same time, software product lines (families of related software products) have been studied with the goal of modeling variability and commonality and building family-based techniques for both modeling and analysis. This thesis presents a novel approach for building an end to end dependability case for a software product line, where a property is formally modeled, a counterexample is found and then …


Domain Adaptation In Unmanned Aerial Vehicles Landing Using Reinforcement Learning, Pedro Lucas Franca Albuquerque Dec 2019

Domain Adaptation In Unmanned Aerial Vehicles Landing Using Reinforcement Learning, Pedro Lucas Franca Albuquerque

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Landing an unmanned aerial vehicle (UAV) on a moving platform is a challenging task that often requires exact models of the UAV dynamics, platform characteristics, and environmental conditions. In this thesis, we present and investigate three different machine learning approaches with varying levels of domain knowledge: dynamics randomization, universal policy with system identification, and reinforcement learning with no parameter variation. We first train the policies in simulation, then perform experiments both in simulation, making variations of the system dynamics with wind and friction coefficient, then perform experiments in a real robot system with wind variation. We initially expected that providing …


Image Classification Using Fuzzy Fca, Niruktha Roy Gotoor Dec 2019

Image Classification Using Fuzzy Fca, Niruktha Roy Gotoor

Department of Computer Science and Engineering: Dissertations, Theses, and Student Research

Formal concept analysis (FCA) is a mathematical theory based on lattice and order theory used for data analysis and knowledge representation. It has been used in various domains such as data mining, machine learning, semantic web, Sciences, for the purpose of data analysis and Ontology over the last few decades. Various extensions of FCA are being researched to expand it's scope over more departments. In this thesis,we review the theory of Formal Concept Analysis (FCA) and its extension Fuzzy FCA. Many studies to use FCA in data mining and text learning have been pursued. We extend these studies to include …


Evaluation Of Modern Missing Data Handling Methods For Coefficient Alpha, Katerina Matysova Dec 2019

Evaluation Of Modern Missing Data Handling Methods For Coefficient Alpha, Katerina Matysova

College of Education and Human Sciences: Dissertations, Theses, and Student Research

When assessing a certain characteristic or trait using a multiple item measure, quality of that measure can be assessed by examining the reliability. To avoid multiple time points, reliability can be represented by internal consistency, which is most commonly calculated using Cronbach’s coefficient alpha. Almost every time human participants are involved in research, there is missing data involved. Missing data means that even though complete data were expected to be collected, some data are missing. Missing data can follow different patterns as well as be the result of different mechanisms. One traditional way to deal with missing data is listwise …