Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 8 of 8

Full-Text Articles in Physical Sciences and Mathematics

Comparing Commonly Used Aquatic Habitat Modeling Methods For Native Fishes, Eryn K. Turney Aug 2023

Comparing Commonly Used Aquatic Habitat Modeling Methods For Native Fishes, Eryn K. Turney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water resources are managed for a variety of human needs, including agriculture, industrial and municipal consumption, hydropower generation, and recreation. There has been a recent push to incorporate habitat needs of aquatic wildlife into water management models alongside these other uses, particularly as competition for limited water resources in a changing climate has reduced instream flow and contributed to declining native fish populations. Habitat models are used to estimate species distributions and differentiate between suitable and unsuitable habitat based on variables important to a given species, but are not usually incorporated into water management models. Because there are many ways …


Quantifying And Predicting Drought Performance In Woody Semi-Arid Seedlings In South Texas: Implications For Enhancing Drought Resilience In Restoration, Zarek Contreras Aug 2022

Quantifying And Predicting Drought Performance In Woody Semi-Arid Seedlings In South Texas: Implications For Enhancing Drought Resilience In Restoration, Zarek Contreras

Theses and Dissertations

Increasingly frequent and severe droughts in the Lower Rio Grande Valley National Wildlife Refuge have been observed to cause large variation in species-specific mortality patterns in young seedlings, spanning 6 – 43 % mortality within the first year. To understand the underlying mechanisms behind this, we subjected seedlings of five woody semi-arid species (Celtis pallida, Forestiera angustifolia, Sideroxylon celastrinum, Phaulothalmnus spinescens, and Zanthoxylum fagara) to a point-of-no-return drought experiment in order to (1) identify potential metrics capable of predicting species wilting and mortality responses, and (2) to understand the underlying mechanisms that correspond to species drought performance …


Developing Early Warning Systems For Debris Flows And Harmful Algal Blooms, Sita Karki Apr 2019

Developing Early Warning Systems For Debris Flows And Harmful Algal Blooms, Sita Karki

Dissertations

This study focused on developing early warning systems for two types of geohazards using methods that heavily rely on remote sensing data. The first investigation attempted to develop a prototype version of an early warning system for landslide development, whereas the second focused on harmful algal bloom prediction.

Construction of intensity-duration (ID) thresholds, and early warning and nowcasting systems for landslides (EWNSL) are hampered by the paucity of temporal and spatial archival data. This work represents significant steps towards the development of prototype EWNSL to forecast and nowcast landslides over Faifa Mountains in the Red Sea Hills. The developed methodologies …


The Effect Of An Historical Geology Course On Students’ Attitudes Towards Science And Their Knowledge Of Deep Time As A Threshold To Their Knowledge Of Evolution, Allan Nolan Aug 2018

The Effect Of An Historical Geology Course On Students’ Attitudes Towards Science And Their Knowledge Of Deep Time As A Threshold To Their Knowledge Of Evolution, Allan Nolan

Dissertations

In America there exists a conflict between a small group of its citizens and the concept of evolution. Researchers have studied this conflict and the ways in which teachers might approach educational methodologies that not only address evolution in a sensitive manner, but also remain legally acceptable.

This research was designed to address teaching evolution in the context of deep time – the concept that time is vast and that geology and biology operate in a timescale of hundreds of millions to billions of years. In previous peer-reviewed works, it has been stated that deep time acts as a threshold …


Efficient Variations Of The Quality Threshold Clustering Algorithm, Frank Loforte Jr. May 2015

Efficient Variations Of The Quality Threshold Clustering Algorithm, Frank Loforte Jr.

CCE Theses and Dissertations

Clustering gene expression data such that the diameters of the clusters formed are no greater than a specified threshold prompted the development of the Quality Threshold Clustering (QTC) algorithm. It iteratively forms clusters of non-increasing size until all points are clustered; the largest cluster is always selected first. The QTC algorithm applies in many other domains that require a similar quality guarantee based on cluster diameter. The worst-case complexity of the original QTC algorithm is (n5). Since practical applications often involve large datasets, researchers called for more efficient versions of the QTC algorithm.

This dissertation aimed to develop …


Identifying A Mechanism For An Infiltration Threshold From The Sunflower River, Ms To The Underlying Alluvial Aquifer, Austin Cole Patton Jan 2015

Identifying A Mechanism For An Infiltration Threshold From The Sunflower River, Ms To The Underlying Alluvial Aquifer, Austin Cole Patton

Electronic Theses and Dissertations

Long-term groundwater level and stream stage measurements at a USGS coupled groundwater stream-gaging station located on the Sunflower River in Sunflower, MS show an apparent stage-threshold for infiltration to the underlying alluvial aquifer. This site is located near the center of a large regional groundwater cone of depression in the Mississippi River Valley alluvial aquifer. The USGS well (termed well 3 in this study) was thought to be completed in the regional shallow aquifer, though often recording anomalously high water levels relative to other wells in the region. The purpose of this research was to identify the responsible mechanism for …


Tor Bridge Distribution Powered By Threshold Rsa, Jordan Hunter Deyton May 2013

Tor Bridge Distribution Powered By Threshold Rsa, Jordan Hunter Deyton

Masters Theses

Since its inception, Tor has offered anonymity for internet users around the world. Tor now offers bridges to help users evade internet censorship, but the primary distribution schemes that provide bridges to users in need have come under attack. This thesis explores how threshold RSA can help strengthen Tor's infrastructure while also enabling more powerful bridge distribution schemes. We implement a basic threshold RSA signature system for the bridge authority and a reputation-based social network design for bridge distribution. Experimental results are obtained showing the possibility of quick responses to requests from honest users while maintaining both the secrecy and …


Some Conclusions Of Statistical Analysis Of The Spectropscopic Evaluation Of Cervical Cancer, Hailun Wang Aug 2008

Some Conclusions Of Statistical Analysis Of The Spectropscopic Evaluation Of Cervical Cancer, Hailun Wang

Mathematics Theses

To significantly improve the early detection of cervical precancers and cancers, LightTouch™ is under development by SpectRx Inc.. LightTouch™ identifies cancers and precancers quickly by using a spectrometer to analyze light reflected from the cervix. Data from the spectrometer is then used to create an image of the cervix that highlights the location and severity of disease. Our research is conducted to find the appropriate models that can be used to generate map-like image showing disease tissue from normal and further diagnose the cervical cancerous conditions. Through large work of explanatory variable search and reduction, logistic regression and Partial Least …