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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

On the seismic response in a large deep-seated landslide in southwest Japan-with special focus on the topographic and geological effects- / 西南日本における大規模深層地すべりの地震応答に関する研究-地形および地質構造の影響-

Ma, Ning 23 May 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21950号 / 理博第4528号 / 新制||理||1650(附属図書館) / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)教授 釜井 俊孝, 教授 千木良 雅弘 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
122

Identificación de puntos críticos en carreteras con riesgo sísmico evaluado con drone topográfico / Identification of critical points on roads with seismic risk evaluated with a topographic drone

Caytuiro Chavez, Jose Alberto, Guevara Solier, Diego Ernesto 09 September 2021 (has links)
Este trabajo de investigación busca identificar, bajo un enfoque determinístico, los riesgos sísmicos a lo largo de una carretera. Además, se empleará un dron topográfico y un GPS diferencial que facilitará la toma de datos georreferenciados. Para nuestro análisis se usó como referencia la metodología REDARS 2 la cual nos ofrece un procedimiento adecuado para la evaluación e identificación de riesgos sísmicos en redes de transporte terrestre en base a un escenario sísmico pertinente en la zona. Los resultados finales abarcan puntos críticos exactos en la Carretera que, debido a sus características, representan un peligro inminente a la estructura y a su funcionabilidad. / This research seeks to identify, under a deterministic approach, seismic risks along a road. In addition, a topographic drone and differential GPS will be used to facilitate the collection of geo-referenced data. For our analysis, the REDARS 2 methodology was used as a reference, which offers us a suitable procedure for the assessment and identification of seismic risks in terrestrial transport networks based on a relevant seismic scenario in the area. The final results cover exacts critical points on the road that, due to their characteristics, represent an imminent danger to the structure and its functionality. / Trabajo de investigación
123

Měření difuzně odrazných povrchů pomocí vírové topografické mikroskopie / Measurement of diffusely reflecting surfaces using vortex topographic microscopy

Pola, Tomáš January 2020 (has links)
This thesis describes an innovative method for topographic measurement of diffuse surfaces. Tested surface is measured indirectly using nanoparticles distributed across the studied area. An image of every particle is captured by CCD camera as a double helix point spread function whose angular rotation corresponds to local surface height. Used point spread function is the result of an interference of non-diffracting vortex beams that are formed by a spiral phase mask from light originating from a nanoparticle. Diploma thesis presents an overview of current techniques for surface topography measurement. Next, working principle of proposed method is described and its experimental application is discussed. An influence of signal-to-noise ratio and image sampling on reconstruction precision is studied using numerical simulations and, as a result, optimal experimental parameters are proposed. Practical potential of the method is demonstrated by 3D reconstruction of planar and spherical surfaces in the depth range of up to 9 times the depth of focus of used microscope objective.
124

Evaluación de productividad del personal y reducción de tiempo en la ejecución de levantamientos topográficos tradicionales de mediana escala mediante el uso de vehículos aéreos no tripulados (Phantom 4 Pro RTK) Caso de aplicación: Departamento de Lambayeque-Chiclayo- Cuculí / Proposal for the reduction of time in the execution of traditional medium-scale topographic surveys through the use of unmanned aerial vehicles (Phantom 4 Pro RTK) Application case: Department of Lambayeque-Chiclayo-Cuculi

Huanachin Cordova, Edwin Rodolfo, León Castañeda, Brandown Chris 17 August 2021 (has links)
Esta investigación comprende en la utilización de una nueva tecnología, que son los UAV (drones), implementados en la ingeniería civil, en el área de topografía, el cual es una opción para ejecutar levantamientos topográficos en terrenos ondulados de zonas rurales. Para realizar estos estudios en campo se contó con el permiso del Centro Poblado Cuculí, provincia de Chiclayo, departamento de Lambayeque. Se usó la topografía tradicional con estación total como base experimental para comparar el tiempo, rendimiento y el error que obtenemos en las proyecciones de las imágenes en el software. Asimismo, se comparará las curvas de nivel y los perfiles longitudinales, a tres diferentes alturas de vuelo (100m, 75m y 65m), que se genera con el software de fotogrametría Agisoft Metashape Professional y complementándolo con el software Autodesk Civil 3D, para luego comparar con el resultado de las curvas y perfiles obtenida mediante el procesamiento de datos con Estación Total. Además, se desarrollaron puntos de control y puntos de apoyo para obtener un modelo de la topografía óptimo. Por otro lado, con el uso de esta metodología de UAV se comprobará que el tiempo en campo se reducen y el rendimiento del personal aumentan, en comparación con el levantamiento tradicional con Estación Total. Por último, estos resultados permitirán una mayor confiabilidad en el uso de UAV en proyectos de obras lineales en un espacio abierto. / Which is an option to carry out topographic surveys on undulating terrain in rural areas. These studies were carried out in the field with the permission of the Cuculí Population Center, Chiclayo province, Lambayeque department. The traditional topography with the total station was used as an experimental base to compare the time, performance, and error that we obtain in the projections of the images in the software. Likewise, the contour lines and the longitudinal profiles will be compared, at three different flight heights (100m, 75m, and 65m), which is generated with the Agisoft Metashape Professional photogrammetry software and complemented with the Autodesk Civil 3D software, to then compare with the result of the curves and profiles obtained by data processing with Total Station. In addition, control points and support points were developed to obtain an optimal topography model. On the other hand, with the use of this UAV methodology, it will be verified that the time in the field is reduced and the performance of the personnel is increased, compared to the traditional survey with Total Station. Finally, these results experienced greater reliability in the use of UAVs in linear works projects in an open space. / Tesis
125

Groundwater investigation at Storsudret, Gotland

Almqvist, Ludvig January 2018 (has links)
Sweden have faced decreasing groundwater storage with critical low groundwater levels for several years. Gotland is one example with issues of providing freshwater due to the low groundwater levels. These circumstances can be related to impacts caused by early agriculture development, an increased demand of freshwater and climate change. There is a need in this region to increase the groundwater storage to ensure enough freshwater. The aim of the study is to increase freshwater storage. Digital geographical information system (GIS) was chosen as a tool in this study in order to cover large geographical areas.  The study was divided into two parts, with focus to determine hydrological and hydrogeological conditions and to identify suitable areas where groundwater storage could be increased. The first part studied: specific capacity, groundwater storage, groundwater balance and topographic wetness index. The second part locked at four methods to increase freshwater storage: Lakes, controlled drainage, wetland and subsurface dam. The result tells us that lakes have the potential to provide freshwater for the municipal distribution network. The controlled drainage method has the ability reduce the outflow of surface water and to increase the groundwater infiltration. Earlier drained wetland areas was identified which could serve as freshwater storage. Suitable areas for subsurface dams were identified. They could work as a large groundwater storage as a decentralized system with the ability to provide groundwater for wells that are spread out. However the identified areas for each methods needs further investigations in more detail to determine the accuracy of the results.
126

Topographic Maps: Image Processing and Path-Finding

Washington, Calin 01 June 2018 (has links) (PDF)
Topographic maps are an invaluable tool for planning routes through unfamiliar terrain. However, accurately planning routes on topographic maps is a time- consuming and error-prone task. One factor is the difficulty of interpreting the map itself, which requires prior knowledge and practice. Another factor is the difficulty of making choices between possible routes that have different trade-offs between length and the terrain they traverse. To alleviate these difficulties, this thesis presents a system to automate the process of finding routes on scanned images of topographic maps. The system allows users to select any two points on a topographic map and identify their specific preferences for their route. This system extracts terrain and contour line data from topographic map images using image processing techniques and then uses the A* Search algorithm to find a route between the specified points. This system can be used as a starting point for hand-drawn routes, as a means of considering alternative routes, or to entirely replace drawing routes by hand. This thesis also presents a user study which shows that this system produces routes in a significantly shorter time than hand-drawn routes, and with a similar level of accuracy.
127

The Structure Of Braid Bars: Facies Relationships of Pleistocene Braided Outwash Deposits, Paris, Ontario

Eynon, George January 1972 (has links)
<p> A large gravel pit at East Paris exposed 14m of Pleistocene braided outwash. Large scale longitudinal bars (30 - 400m long) were developed utilising irregular topographic highs (4 - 6m) of the basal gravels as Bar Cores. These bars prograded downstream by means of larce-scale cross-strata, periodically interupted by reactivation surfaces. Contemparaneous upstream addition of material took place by the migr ation of mixed sand and gravel bed-forms on the stoss-side of the bars. The gravel supply to the avalanche face of the major bars took the form of imbricated gravels which passed from the stoss-side, through the Bar Top, onto the Bar Front. Adjacent, sandy side-channels (4 -6m deep) exhibit a fining upward fill of trough cross beds, planar lamination and ripples; and interdigitated with the gravel bars alongside. </p> <p> Aggradation of the flood plain led to the extension of the Bar Top facies over the length of the bars, and then to the development of a Shallow-braided stream facies over the whole system. The latter is recognised by its smaller (less than 1m) bar forms composed of crossbedded gravel supplied by an imbricate gravel, and numerous small, sandy channel forms. </p> <p> At West Paris another large gravel pit exposed 6m of sandier, but stratigraphically equivalent deposits. Large scale side-bar accumulations (200-300m across) of gravel developed from river bank lateral accretion deposits. The downstream progradation was by lobes of cross-stratified and imbricated gravels, alternating with sand drapes of low flow stages. Sandy Side-channels (4m deep) developed between the gravel lobes and the accreting river bank. </p> <p> The concept of braid bar growth from a pre-existing form (bar core or river bank) is in contrast to the classic theory of development from a gravel lag. The differences may be due to depth relationships of the systems, which in this case may be the effect of position on the sandur surface. </p> / Thesis / Master of Science (MSc)
128

Developing a Forest Gap Model to Be Applied to a Watershed-scaled Landscape in the Cross Timbers Ecoregion Using a Topographic Wetness Index

Goetz, Heinrich (Heinrich Erwin) 08 1900 (has links)
A method was developed for extending a fine-scaled forest gap model to a watershed-scaled landscape, using the Eastern Cross Timbers ecoregion as a case study for the method. A topographic wetness index calculated from digital elevation data was used as a measure of hydrologic across the modeled landscape, and the gap model modified to have with a topographically-based hydrologic input parameter. The model was parameterized by terrain type units that were defined using combinations of USDA soil series and classes of the topographic wetness index. A number of issues regarding the sources, grid resolutions, and processing methods of the digital elevation data are addressed in this application of the topographic wetness index. Three different grid sizes, 5, 10, and 29 meter, from both LiDAR-derived and contour-derived elevation grids were used, and the grids were processed using both single-directional flow algorithm and bi-directional flow algorithm. The result of these different grids were compared and analyzed in context of their application in defining terrain types for the forest gap model. Refinements were made in the timescale of gap model’s weather model, converting it into a daily weather generator, in order to incorporate the effects of the new topographic/hydrologic input parameter. The precipitation model was converted to use a Markov model to initiate a sequence of wet and dry days for each month, and then daily precipitation amounts were determined using a gamma distribution. The output of the new precipitation model was analyzed and compared with a 100-year history of daily weather records at daily, monthly, and annual timescales. Model assumptions and requirements for biological parameters were thoroughly investigated and questioned. Often these biological parameters are based on little more than assumptions and intuition. An effort to base as many of the model’s biological parameters on measured data was made, including a new technique for estimating optimal volumetric growth rate by measuring tree rings. The gap model was set up to simulate various terrain types within the landscape.
129

Optimizing Remote Sensing Methodology for Burial Mounds in the United States and United Kingdom

Corkum II, Alexander C. January 2019 (has links)
Within the archaeological record ‘mounds’ are often ubiquitous. They are common in many ancient cultures, and they vary in size, construction techniques and use. This research is focused upon optimizing the use of remote sensing for the non-invasive study of mounds both in the United States and the United Kingdom. This thesis presents three representative earthen mound sites and proposes a comprehensive and modular survey methodology to guide the planning and execution of a mound survey tailored to the unique requirements presented by the cultural resource at a particular location. In doing so, the research has provided optimized approaches to high resolution three-dimensional topographic models using a variety of digital methods. These models have been shown to accurately capture the variability of the modern ground surface, which is of vital importance to the management of the mounds. Furthermore, these models have proved vital for integrating geophysical methods into the holistic workspace, thereby providing a better archaeological understanding of the below ground remains. Every mound surveyed presented different challenges, and therefore had to be approached in a slightly different way. However, the general methodology was highly effective for both characterizing below-ground archaeological and natural anomalies, and for assessing the state of preservation of all mounds surveyed. As a result, a flowchart has been generated for non-invasive assessment of mounds in general. If followed, this will allow the production of a “snapshot” of the mound or mound group at a fixed point in time with the resolution necessary to produce useful and insightful interpretation. While this research focuses on the application of geophysical and topographic survey in the United Kingdom and United States to a mound or mound group, this methodology and the associated outcomes can be valuable more globally not only for archaeology, but also heritage management.
130

Prediction of Travel Time and Development of Flood Inundation Maps for Flood Warning System Including Ice Jam Scenario. A Case Study of the Grand River, Ohio

Lamichhane, Niraj 23 May 2016 (has links)
No description available.

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