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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.
171

An environmental assessment of Bermuda's caves

Gibbons, Darcy Ann 17 February 2005 (has links)
The current environmental status of the majority of Bermuda’s one hundred sixty-six known caves was investigated. This survey replicated a historical cave study performed in 1983, wherein each was analyzed for positive and negative features. Statistical analysis of the data showed a significant difference between the historical and current survey ratings, with an overall decrease in environmental status. A water quality study was performed on twenty different caves with sea level pools in various locations around the island. Nitrate, nitrite, ammonia, and phosphate levels were measured from varying depths in these caves. Fifteen of these caves were also tested for the presence of fecal bacterial contamination. High nitrate levels were discovered in some of the caves, particularly in surface samples. Additionally, bacterial contamination was detected in some caves. No obvious relationship between cave size or location and contamination existed for any of the pollutants sampled. Three separate caves from this group were dived and analyzed using a Hydrolab Sonde 3 Multiprobe Logger to acquire in situ water column data including depth, temperature, pH, salinity, and dissolved oxygen. Each cave studied had its own unique trends in hydrology at varying depths in the water column. A later water sampling study with a randomized experimental design was created and caves were divided into four classes based on size and location. Surface and subsurface samples were gathered from twelve randomly selected caves, three from each class. Each sample was analyzed for nitrate, nitrite, and ammonia concentrations. The results were analyzed using multiple analysis of variance statistics. A significant difference between the nitrate concentrations in the surface and subsurface water samples was discovered. None of the other comparisons were statistically significant. To represent the data visually, a Bermuda Cave and Karst Information System (BeCKIS) was created using the environmental survey data and water quality information. Some of the maps generated highlighted regions where negative environmental impacts on caves were concentrated geographically, thus demonstrating how this geographic information system could be used as a conservation tool.
172

ニホンザルの洞窟利用と化石化過程 (予案)

Senokuchi, Yoshitaka, Abe, Yuji, Kashiwagi, Kenji, 瀬之口, 祥孝, 阿部, 勇治, 柏木, 健司 03 1900 (has links)
名古屋大学年代測定総合研究センターシンポジウム報告
173

紀伊半島東部の霧穴(石灰岩洞窟)産哺乳類遺体の炭素14年代とその意義

Takagi, Marie, Abe, Yuji, Kashiwagi, Kenji, 高木, まりゑ, 阿部, 勇治, 柏木, 健司 03 1900 (has links)
第22回名古屋大学年代測定総合研究センターシンポジウム平成21(2009)年度報告
174

An environmental assessment of Bermuda's caves

Gibbons, Darcy Ann 17 February 2005 (has links)
The current environmental status of the majority of Bermuda’s one hundred sixty-six known caves was investigated. This survey replicated a historical cave study performed in 1983, wherein each was analyzed for positive and negative features. Statistical analysis of the data showed a significant difference between the historical and current survey ratings, with an overall decrease in environmental status. A water quality study was performed on twenty different caves with sea level pools in various locations around the island. Nitrate, nitrite, ammonia, and phosphate levels were measured from varying depths in these caves. Fifteen of these caves were also tested for the presence of fecal bacterial contamination. High nitrate levels were discovered in some of the caves, particularly in surface samples. Additionally, bacterial contamination was detected in some caves. No obvious relationship between cave size or location and contamination existed for any of the pollutants sampled. Three separate caves from this group were dived and analyzed using a Hydrolab Sonde 3 Multiprobe Logger to acquire in situ water column data including depth, temperature, pH, salinity, and dissolved oxygen. Each cave studied had its own unique trends in hydrology at varying depths in the water column. A later water sampling study with a randomized experimental design was created and caves were divided into four classes based on size and location. Surface and subsurface samples were gathered from twelve randomly selected caves, three from each class. Each sample was analyzed for nitrate, nitrite, and ammonia concentrations. The results were analyzed using multiple analysis of variance statistics. A significant difference between the nitrate concentrations in the surface and subsurface water samples was discovered. None of the other comparisons were statistically significant. To represent the data visually, a Bermuda Cave and Karst Information System (BeCKIS) was created using the environmental survey data and water quality information. Some of the maps generated highlighted regions where negative environmental impacts on caves were concentrated geographically, thus demonstrating how this geographic information system could be used as a conservation tool.
175

Relational cohesion in Palaeolithic Europe : hominin-cave bear interactions in Moravia and Silesia, Czech Republic, during OIS3

Skinner, Patrick Joseph January 2011 (has links)
No description available.
176

Augmented Reality in CAVE / Augmented Reality in CAVE

Kolčárek, Michal January 2013 (has links)
Tato práce se zaměřuje na technologii Cave Automatic Virtual Environment a konkrétně pak na využití principů rozšířené reality v tomto prostředí. Dává si za cíl odpovědět na otázku, zdali je možné použít v prostředí CAVE existující frameworky pro rozšířenou realitu, konkrétně ty, pracující na platformě iOS. Hlavní důraz je kladen na rozpoznávání markerů v tomto prostředí a na zvýšení přesnosti jejich rozpoznání. Práce odpovídá na množství otázek z této oblasti, jako jaké markery je vhodné použít, jaké jsou omezení a největší obtíže. Výstupem je demonstrační aplikace, pracující na platformě iOS, která v je prostředí CAVE otestovaná a plně použitelná. Tato aplikace by měla vylepšit uživatelský vjem z prostředí CAVE tím, že mu poskytne dodatečné informace a také základní možnosti interakce se zobrazenými objekty.
177

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.
178

Internet GIS as a Historic Place-Making Tool for Mammoth Cave National Park

Epperson, Ann E. 01 December 2010 (has links)
This project laid the groundwork for an Internet-delivered Public Participation Geographic Information System to facilitate exploration and discovery of the past communities of the Mammoth Cave Park area. The emergence of Internet Web 2.0 design along with distributed GIS services allows for anyone to interact with and add to the information found on central Internet sites. Historical geography often relies upon public participation from individuals outside the academic world to provide narrative descriptions, photographs and manuscripts of past places and events to augment information held by institutions and academia. A public-participation website for the Mammoth Cave Historic GIS (MCHGIS) created a central Internet location for dispersed and disparate data related to pre-park communities to be presented with a geographic context. The MCHGIS project allowed for visualization of the pre-park communities in unique ways and contributed new understandings of this pre-park area.
179

I inneslutande VR : En kvalitativ undersökning om användares närvarokänsla första gången de befinner sig i en virtuell miljö.

Gustafsson, Jenny, Phensadsaeng, Arachaya January 2006 (has links)
<p>Syftet med denna uppsats är att göra en undersökning om vilka faktorer som påverkar användares närvarokänsla första gången de använder sig av en inneslutande virtuell miljö. De inneslutande VR tekniker vi har valt att fokusera på är Computer Automatic Virtual Environment (Cave) och Head Mounted Display (HMD).</p><p>Forskaren Carrie Heeter beskriver tre typer av närvaro och forskarna Wallace Sadowski och Kay Stanney räknar upp faktorer som de påstår påverkar användarens närvarokänsla.</p><p>Vår frågeställning är vilka likheter eller skillnader det finns mellan våra testpersoners svar och Sadowski och Stanneys faktorer. Vi intervjuade och genomförde ett test med tre testpersoner i en Computer Automatic Virtual Environment baserat på två program. Vi valde även att intervjua två experter om vilka faktorer de ansåg påverkade deras närvarokänsla första gången de använde sig av en HMD.</p><p>Första programmet som testpersonerna fick pröva på var Cuevadefuego som bestod av tredimensionella bilder till skillnad från det andra programmet, Crayoland, som bestod av tvådimensionella bilder. Intervjufrågorna till testpersonerna och experterna baserades på frågor som handlade om experternas och testpersonernas reaktioner och intryck relaterat till deras närvarokänsla och vad de trodde det var som påverkade deras närvarokänsla.</p><p>Resultatet av intervjuerna och testet är att det finns likheter mellan de faktorer som testpersonerna anser påverkar deras närvarokänsla och med Sadowski och Stanneys faktorer men inga direkta skillnader.</p>
180

Kartchner Caverns: Habitat Scale Community Diversity and Function in a Carbonate Cave

Ortiz-Ortiz, Marianyoly January 2012 (has links)
This dissertation examines the microbial and functional diversity in Kartchner Caverns, a limestone cave in Arizona, USA. Kartchner is highly oligotrophic due to the lack of photosynthesis and the limited inputs of organic material from the surface. This characteristic poses a challenge for microbial life in the cave. The first objective of this work was to evaluate the bacterial richness, diversity and taxonomic composition of speleothems surfaces within Kartchner Caverns in order to gain insight into the distribution patterns associated with these communities. Secondly, the metabolic strategies used by cave communities to survive harsh cave conditions were investigated based on phylogenetic associations and metagenomics. Both objectives were directed toward answering the questions "who are there?" and "what are they doing?". The 454-pyrotag analysis of the V6 region of the 16S rRNA gene revealed an unexpectedly high bacterial diversity with each speleothem supporting a unique bacterial community profile. A focused study on one room of the cave revealed three community types: Type 1 was dominated by the phylum Proteobacteria; Type 2 by Actinobacteria; and Type 3 by Acidobacteria. Phylogenetic associations of the sequences generated by the 454 sequencing and by a Sanger clone library suggested cave microbial communities are supported by chemoautotrophic activities such as nitrite and iron oxidation. Results from the phylogenetic associations guided the metagenomic analysis which supports the presence of chemoautotrophic activities in the cave. Genes for two complete CO2 fixation mechanisms, the Calvin-Benson-Bashan and the rTCA cycles were identified in the cave metagenome, as well as genes for ammonia and nitrite oxidation. These genes are associated with both Bacteria and Archaea suggesting members of both domains are acting as primary producers in the cave ecosystem. Comparative analysis of cave samples to other environments suggests an overabundance of DNA repair mechanisms which could be potentially used by cave communities to overcome the toxicity due to high concentrations of calcium on the speleothem surfaces. This work provides the first comprehensive analysis of the microbial diversity and potential strategies used by microbial communities to survive under the extreme conditions found in a semi-arid limestone cave environment.

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