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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Comparing Structure from Motion Photogrammetry and Computer Vision for Low-Cost 3D Cave Mapping: Tipton-Haynes Cave, Tennessee

Elmore, Clinton 01 August 2019 (has links)
Natural caves represent one of the most difficult environments to map with modern 3D technologies. In this study I tested two relatively new methods for 3D mapping in Tipton-Haynes Cave near Johnson City, Tennessee: Structure from Motion Photogrammetry and Computer Vision using Tango, an RGB-D (Red Green Blue and Depth) technology. Many different aspects of these two methods were analyzed with respect to the needs of average cave explorers. Major considerations were cost, time, accuracy, durability, simplicity, lighting setup, and drift. The 3D maps were compared to a conventional cave map drafted with measurements from a modern digital survey instrument called the DistoX2, a clinometer, and a measuring tape. Both 3D mapping methods worked, but photogrammetry proved to be too time consuming and laborious for capturing more than a few meters of passage. RGB-D was faster, more accurate, and showed promise for the future of low-cost 3D cave mapping.
122

Improving Sinkhole Mapping Using LiDAR Data and Assessing Road Infrastructure at Risk in Johnson City, TN.

Fasesin, Kingsley, Luffman, Ingrid, Ernenwein, Eileen, Nandi, Arpita 05 April 2018 (has links)
Improving Sinkhole Mapping Using LiDAR Data and Assessing Road Infrastructure at Risk in Johnson City, TN. Kingsley Fasesin1, Dr. Ingrid Luffman 1, Dr. Eileen Ernenwein 1 and Dr. Arpita Nandi1 1 Department of Geosciences, College of Arts and Sciences, East Tennessee State University, Johnson City, TN; Abstract Predicting infrastructure damage and economic impact of sinkholes along roadways requires mapping of sinkhole distribution and development of a model to predict future occurrences with high accuracy. The study is carried out to define the distribution of sinkholes in Johnson City, TN and risks they pose to roads in the city. The study made use of a 2.5 ft Digital Elevation Model (DEM) derived from Light Detection and Ranging (LiDAR) data acquired from Tennessee Geospatial clearing house (TNGIS) and an inventory of known sinkholes identified from topographic maps. Depressions were identified using the LiDAR-derived DEM by subtracting a filled-depressions DEM from the original study area DEM. Using a spatial join, mapped sinkholes were matched to depression polygons identified from the LiDAR-derived DEM. For all matched sinkhole-polygon pairs, three indices were calculated: circularity index, area ratio of minimum bounding rectangle, and proximity to train tracks and roads. The dataset was partitioned into training (70%) and validation (30%) subsets, and using the training dataset, thresholds for each index were selected using typical values for known sinkholes. These rules were calibrated using the 30% validation subset, and applied as filters to the remaining unmatched depression polygons to identify likely sinkholes. A portion of these suspected sinkholes were field checked. The future direction of this research is to generate a sinkhole formation model for the study area by examining the relationship between the mapped sinkhole distribution, and previously identified sinkhole formation risk factors. These factors include: proximity to fault lines, groundwater and streams; depth to bedrock; and soil and land cover type. Spatial Logistic Regression analysis will be used for model development, and results will be used to generate a sinkhole susceptibility map which will be overlain on the road network to identify the portions of interstate and state highways at risk of sinkhole destruction.
123

Shellfish Harvest on the Coast of British Columbia: The Archaeology of Settlement and Subsistence through High-resolution Stable Isotope Analysis and Sclerochronology

Burchell, Meghan 04 1900 (has links)
<p>In many interpretations of hunter-gatherer settlement systems, archaeologists have assumed implicitly or explicitly that a pattern of mobilitybased on seasonally-scheduled movements between different site locations waspracticed. This pattern of mobility is often characterized as a seasonal round, where different locations are used during specific times of the year for different purposes. An implication of this pattern of mobility is that short-term occupation sites are visited annually, approximately at the same time each year and longer-term residential sites can span multiple seasons. To interpret seasonality, indirect indicators are often used but the high-resolution methods presented in this study provide direct evidence of seasonal site occupation. The Pacific Northwest Coast provides an ideal landscape to examine seasonality since many of the staple resources, particularly salmon, were available on a seasonal basis. Contrary to longstanding assumptions of regular seasonal movement between sites, the analysis of shell samples from multiple archaeological sites from distinct regions in British Columbia show complex patterns of multi-seasonal occupation at smaller campsites and specific seasonal or multi-seasonal emphasis in occupation and/or shellfish harvest at longer-term residential sites.</p> <p>To identify patterns of shellfish harvest, stable oxygen isotope analysis and high-resolution sclerochronology were applied to the bivalve <em>Saxidomus gigantea</em> (butter clam). Combined with shell growth increment analysis to examine relative levels of harvest pressure, local rates of shellfish collecting are also interpreted. To examine regional variability in seasonality and resource use in British Columbia, three environmentally and historically distinct areas were selected spanning approximately 6000 years of history. These regions include the central coast in the tradition territory of the Heiltsuk, and two areas on the northern coast, specifically the Dundas Islands Group and Prince Rupert Harbour in the traditional territory of the Tsimshian. The results of the analysis show site-specific trends in shellfish harvesting on the central coast; a pattern which is not as clear on the northern coast. Sites on the Dundas Islands show multi-seasonal collection and a stronger emphasis on winter shellfish harvesting. The results also show that shellfish were harvested more intensively in the Dundas Islands area relative to the central coast. The pattern of seasonal shellfish harvesting on the mainland coast at village sites in Prince Rupert Harbour is similar to the pattern found at long-term residential sites on the central coast. With respect to the dietary importance of clams, another longstanding issue in Northwest Coast archaeology, the results show a mix of patterns including casual resource use at most campsites, intensive multi-season harvest in some regions and strategic multi-season harvest and spring consumption at some residential sites.</p> / Doctor of Philosophy (PhD)
124

Tectonomorphic and kinematic characterization of Neogene deformation in the southern Central Andes (23˚-28˚S, NW Argentina)

Daxberger, Heidi 10 1900 (has links)
<p>This thesis focuses on the tectonomorphologic evolution of the Central Andean Puna Plateau and its eastern foreland. The collective findings of fault-slip and tectonomorphic analyes help in understanding the mechanical behavior of non-collisional orogens at convergent plate boundaries and result in an improved Neogene tectonic record of the Central Andes.</p> <p>Fault-slip analysis indicates Neogene WNW-ESE horizontal shortening of the thickened crust of the Puna Plateau and Eastern Cordillera and simultaneous lateral gravitational spreading. The less thickened of Pampean Ranges continue to undergo horizontal shortening only. The importance of N-S extension in the kinematics of elevated parts of the Central Andes is underscored by the strike-slip components on prominent dip-slip faults. Strain axis configurations in the southern Central Andes are generally controlled by (1) overall WNW-ESE horizontal shortening imposed by plate convergence and (2) differences in crustal thickness, i.e., gravitational potential energy. Therefore, a geodynamic interpretations in which still increasing elevation and crustal thickness significantly influence upper-crustal kinematics of the southern Central Andes is suggested.</p> <p>To allow regional-scale tectonomorphic studies, including Valley-Width-to-Valley-Height (Vf) ratio and the Transverse-Topographic-Symmetry (T-) factor, an Esri ArcGIS compatible software tool was developed. This Geographical Information System (GIS)-based tool, was coded in Python to enable conversion to other ArcGIS versions. This herein presented first version of the tool is fully functioning and drastically reduces the otherwise long processing times.</p> <p>A qualitative main basin symmetry description, Mountain-Front-Sinuosity (Smf) indices, and Vf-ratios of second-order drainage basins, indicate ubiquitous Quaternary deformation on reverse and thrust faults in the southern Central Andes. The recorded Quaternary deformation strongly influences Quaternary landform development, as shown by main drainage basin asymmetries and second-order drainage basins shapes. However, non-systematic T-factor distribution for second-order basins indicates that basin asymmetry is subject to litholigcal variations.</p> / Doctor of Philosophy (PhD)
125

Development and evaluation of seasonal, continental-scale streamflow forecasts

Yeates, Elissa Marie 13 May 2022 (has links)
Methods of forecasting streamflow using atmospheric ensembles and hydrologic routing have greatly improved over the past decades. These forecasts anticipate the timing and magnitude of streamflow peaks, enabling early warning of floods. Recent advances in atmospheric modeling have enabled production of forecasts months ahead, which are less precise but give a useful sense of trends. The purpose of this study is to produce and evaluate a seasonal streamflow forecast model using a Muskingum routing hydrologic model coupled with runoff from a land surface model, and atmospheric input from a medium-term atmospheric and precipitation model. To evaluate the skill of the coupled model, resultant streamflow forecasts with lead times up to 90 days are compared with stream gage data across the three-year historical period of interest. The coupled model system performed well in downstream reaches and with shorter lead times, but forecast skill degraded for lead times past 15 days.
126

Meeting-places of Transformation : Urban Identity, Spatial Representations and Local Politics in St Petersburg, Russia

Borén, Thomas January 2005 (has links)
<p>This study develops a model for understanding spatial change and the construction of space as a meeting-place, and then employs it in order to show an otherwise little-known picture of (sub-)urban Russia and its transformation from Soviet times to today. The model is based on time-geographic ideas of time-space as a limited resource in which forces of various kinds struggle for access and form space in interaction with each other. Drawing on cultural semiotics and the concepts of lifeworld and system, the study highlights the social side of these space-forming forces. Based on a long-term fieldwork (participant observation) in Ligovo/Uritsk, a high-rise residential district developed around 1970 and situated on the outskirts of Sankt-Peterburg (St Petersburg), the empirical material concerns processes of urban identity, spatial representations and local politics. The study explicates three codes used to form the image of the city that all relate to its pre-Revolutionary history, two textual strategies of juxtaposition in creating the genius loci of a place, and a discussion of what I call Soviet "stiff landscape" in relation to Soviet mental and ordinary maps of the urban landscape. Moreover, the study shows that the newly implemented self-governing municipalities have not realised their potential as political actors in forming local space, which raises questions on the democratisation of urban space. Finally, the study argues that the model that guides the research is a tool that facilitates the application of the world-view of time-geography and the epistemology of the landscape of courses in concrete research. The study ends with an attempt to generalise spatial change in four types.</p>
127

Meeting-places of Transformation : Urban Identity, Spatial Representations and Local Politics in St Petersburg, Russia

Borén, Thomas January 2005 (has links)
This study develops a model for understanding spatial change and the construction of space as a meeting-place, and then employs it in order to show an otherwise little-known picture of (sub-)urban Russia and its transformation from Soviet times to today. The model is based on time-geographic ideas of time-space as a limited resource in which forces of various kinds struggle for access and form space in interaction with each other. Drawing on cultural semiotics and the concepts of lifeworld and system, the study highlights the social side of these space-forming forces. Based on a long-term fieldwork (participant observation) in Ligovo/Uritsk, a high-rise residential district developed around 1970 and situated on the outskirts of Sankt-Peterburg (St Petersburg), the empirical material concerns processes of urban identity, spatial representations and local politics. The study explicates three codes used to form the image of the city that all relate to its pre-Revolutionary history, two textual strategies of juxtaposition in creating the genius loci of a place, and a discussion of what I call Soviet "stiff landscape" in relation to Soviet mental and ordinary maps of the urban landscape. Moreover, the study shows that the newly implemented self-governing municipalities have not realised their potential as political actors in forming local space, which raises questions on the democratisation of urban space. Finally, the study argues that the model that guides the research is a tool that facilitates the application of the world-view of time-geography and the epistemology of the landscape of courses in concrete research. The study ends with an attempt to generalise spatial change in four types.
128

Spatiotemporal Analyses of Recycled Water Production

Archer, Jana E. 01 May 2017 (has links)
Increased demands on water supplies caused by population expansion, saltwater intrusion, and drought have led to water shortages which may be addressed by use of recycled water as recycled water products. Study I investigated recycled water production in Florida and California during 2009 to detect gaps in distribution and identify areas for expansion. Gaps were detected along the panhandle and Miami, Florida, as well as the northern and southwestern regions in California. Study II examined gaps in distribution, identified temporal change, and located areas for expansion for Florida in 2009 and 2015. Production increased in the northern and southern regions of Florida but decreased in Southwest Florida. Recycled water is an essential component water management a broader adoption of recycled water will increase water conservation in water-stressed coastal communities by allocating recycled water for purposes that once used potable freshwater.
129

NATURAL PHENOMENA AS POTENTIAL INFLUENCE ON SOCIAL AND POLITICAL BEHAVIOR: THE EARTH’S MAGNETIC FIELD

East, Jackie R 01 January 2014 (has links)
Researchers use natural phenomena in a number of disciplines to help explain human behavioral outcomes. Research regarding the potential effects of magnetic fields on animal and human behavior indicates that fields could influence outcomes of interest to social scientists. Tests so far have been limited in scope. This work is a preliminary evaluation of whether the earth’s magnetic field influences human behavior it examines the baseline relationship exhibited between geomagnetic readings and a host of social and political outcomes. The emphasis on breadth of topical coverage in these statistical trials, rather than on depth of development for any one model, means that evidence is only suggestive – but geomagnetic readings frequently covary with social and political variables in a fashion that seems inexplicable in the absence of a causal relationship. The pattern often holds up in more-elaborate statistical models. Analysis provides compelling evidence that geomagnetic variables furnish valuable information to models. Many researchers are already aware of potential causal mechanisms that link human behavior to geomagnetic levels and this evidence provides a compelling case for continuing to develop the line of research with in-depth, focused analysis.
130

USING GIS TO DELINEATE HEADWATER STREAM ORIGINS IN THE APPALACHIAN COAL-BELT REGION OF KENTUCKY

Villines, Jonathan A. 01 January 2013 (has links)
Human activity such as surface mining can have substantial impacts on the natural environment. Performing a Cumulative Hydrologic Impact Assessment (CHIA) of such impacts on surface water systems requires knowing the location and extent of these impacted streams. The Jurisdictional Determination (JD) of a stream’s protected status under the Clean Water Act (CWA) involves locating and classifying streams according to their flow regime: ephemeral, intermittent, or perennial. Due to their often remote locations and small size, taking a field inventory of headwater streams for surface mining permit applications or permit reviews is challenging. A means of estimating headwater stream location and extent, according to flow regime using publicly available spatial data, would assist in performing CHIAs and JDs. Using headwater point-of-origin data collected from Robinson Forest in eastern Kentucky along with data from three JDs obtained via a Freedom of Information Act (FOIA) request to the U.S. Army Corps of Engineers (USACE), headwater streams in the Appalachian Coal Belt were characterized according to a set of spatial parameters. These characteristics were extrapolated using GIS to delineate headwater streams over a larger area, and the results were compared to the National Hydrography Dataset (NHD).

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