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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.
21

Application of optical techniques to moving surface measurements

Stewart, James Neil January 1990 (has links)
No description available.
22

Shape classification : towards a mathematical description of the face

Coombes, Anne Margaret January 1993 (has links)
Recent advances in biostereometric techniques have led to the quick and easy acquisition of 3D data for facial and other biological surfaces. This has led facial surgeons to express dissatisfaction with landmark-based methods for analysing the shape of the face which use only a small part of the data available, and to seek a method for analysing the face which maximizes the use of this extensive data set. Scientists working in the field of computer vision have developed a variety of methods for the analysis and description of 2D and 3D shape. These methods are reviewed and an approach, based on differential geometry, is selected for the description of facial shape. For each data point, the Gaussian and mean curvatures of the surface are calculated. The performance of three algorithms for computing these curvatures are evaluated for mathematically generated standard 3D objects and for 3D data obtained from an optical surface scanner. Using the signs of these curvatures, the face is classified into eight 'fundamental surface types' - each of which has an intuitive perceptual meaning. The robustness of the resulting surface type description to errors in the data is determined together with its repeatability. Three methods for comparing two surface type descriptions are presented and illustrated for average male and average female faces. Thus a quantitative description of facial change, or differences between individual's faces, is achieved. The possible application of artificial intelligence techniques to automate this comparison is discussed. The sensitivity of the description to global and local changes to the data, made by mathematical functions, is investigated. Examples are given of the application of this method for describing facial changes made by facial reconstructive surgery and implications for defining a basis for facial aesthetics using shape are discussed. It is also applied to investigate the role played by the shape of the surface in facial recognition.
23

A block model for submarine slides involving hydroplaning

Hu, Hongrui, January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.
24

Studies of deep-sea sedimentary microtopography in the North Atlantic ocean /

Flood, Roger D. January 1978 (has links)
Thesis--Massachusetts Institute of Technology / Woods Hole Oceanographic Institution. / Vita. Includes bibliographical references (p. 333-347).
25

Sensitivity studies using multi-region and open boundary conditions for terrain bottom following ocean models

Martinho, Antonio S. January 2003 (has links) (PDF)
Thesis (Ph. D. in Physical Oceanography)--Naval Postgraduate School, March 2003. / Dissertation supervisor: Batteen, Mary L. "March 2003." Includes bibliographical references (p. 167-168). Also available in print. Mode of access: World Wide Web.
26

Effects of finite amplitude bottom topography on ocean variability

Leonov, Dmitri A. Dewar, William K. January 2005 (has links)
Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. William K. Dewar, Florida State University, College of Arts and Sciences, Dept. of Oceanography. Title and description from dissertation home page (viewed Sept. 23, 2005). Document formatted into pages; contains xi, 61 pages. Includes bibliographical references.
27

A heuristic approach to the evaluation of seafloor bathymetric changes : a case study of Dundee Harbour, Eastern Scotland

Zin, Harun Shah Bin Mat January 1997 (has links)
The phenomena of seabed bathymetric changes in Dundee harbour, eastern Scotland have been investigated, by use of archive bathymetric data. The bathymetric data were available from the Dundee Port Authority, from its past annual harbour maintenance programmes during the period of 1989 to 1993. Archive bathymetric data are seen as under-utilised, after being used for their intended purposes. A methodology was therefore developed to use sequential bathymetric data to estimate the deposition and erosion of sediment over a period of time. This is in the form of a systematic procedure of processing for comparison of data from different dates. The comparison or differencing of bathymetric data in their original form cannot be directly applied. This would require each data point to be located at spatially common positions (i.e. grid points) and could be achieved only through interpolation. A procedure known as 'gridding' is instead used to prepare depths at the spatially fixed points or nodes. Six different methods of interpolation have been examined and trial computations using a common data subset for each individual method conducted. The results of the interpolation were often substantially different from one method to another. A technique known as the Blending Interpolation Technique is proposed to overcome the uncertainty in depth interpolation. Computer programs were specifically written for this study and for the visualisation of the phenomena of deposition and erosion, use was made of the available UNIRAS software package. The methodology and procedures of this study are not only applicable for an estuarine harbour environment, but are also equally applicable to any areas such as large reservoirs, lakes or coastal ports and harbours, that are continuously affected by the phenomena of sedimentation and erosion, where their estimation and quantification are of critical importance. This study, however, has demonstrated the usefulness of the Blending Interpolation Technique which is seen as a future tool to detect, monitor and quantify seabed changes, in particular where bathymetric data of the same area are available from different dates. It also serves to prolong the usefulness of archive bathymetric data kept for an area.
28

Better Coverage of Arizona's Weather and Climate: Gridded Datasets of Daily Surface Meteorological Variables

Weiss, Jeremy, Crimmins, Michael 08 1900 (has links)
7 pp. / Many areas that use agricultural and environmental science for management and planning – ecosystem conservation, crop and livestock systems, water resources, forestry and wildland fire management, urban horticulture – often need historical records of daily weather for activities that range from modeling forage production to determining the frequency of freezing temperatures or heavy rainfall. In the past, such applications primarily have used station-based observations of meteorological variables like temperature and precipitation. However, weather stations are sparsely and irregularly located throughout Arizona, and due to the highly variable terrain across the state (Figure 1), information recorded at these sites may not represent meteorological conditions at distant, non-instrumented locations or over broad areas. This issue, along with others related to quality, length, and completeness of station records, can hinder the use of weather and climate data for agricultural and natural resources applications. In response to an increasing demand for spatially and temporally complete meteorological data as well as the potential constraints of station-based records, the number of gridded daily surface weather datasets is expanding. This bulletin reviews a current suite of these datasets, particularly those that integrate both atmospheric and topographic information in order to better model temperature and precipitation on relatively fine spatial scales, and is intended for readers with knowledge of weather, climate, and geospatial data. In addition to addressing how these datasets are developed and what their spatial domain and resolution, record length, and variables are, this bulletin also summarizes where and how to access these datasets, as well as the general suitability of these datasets for different uses.
29

The geometry of architecture: Using topological surfaces to design a soccer stadium in downtown New Orleans

January 2017 (has links)
Navigating an airport would be nearly impossible without proper signage. The number of gates, the different zones of access, the layers of conveyor belts running through the floors all provide a challenge for the architect designing the airport, even before the signs are sketched out. Projects such as airports or sporting arenas provide an extreme challenge in programmatic proximities for any designer working to make a building's circulation flow. Topology is a branch of mathematics focusing on the geometry of position and connection. By using it in architecture, program connections can be simplified and made into diagrams of edges and nodes. By taking out scale and shape, the problem is made only about connection and proximity. Applying this topological method to a professional soccer stadium in New Orleans puts the process to the test. The complexities of the public and service areas and how they interact creates a need for simplification, otherwise the building will exceed any manageable construction scale. / 0 / SPK / specialcollections@tulane.edu
30

Pleistocene Shallow Braided Outwash Near Galt

Bourque , P.L. 05 1900 (has links)
<p>A gravel pit west of Galt exposed about 6m of shallow braided outwash gravels which overlie deposits of unknown origin with eroded topography. The outwash shows two cycles of coarse sediment deposition with a relatively quiet period between. The lower cycle fines upwards from coarse gravel, through cross-bedded pebbly sand, to silty ripple-drift. The upper cycle erodes the silty sand and coarsens upwards from pebbly sand cross-beds to cobble gravel of longitudinal bars. These bars can be shown by their internal sandy horizons and stoss side sandy deposits to have grown by deposition at their upstream end. </p><p>The two major depositional cycles are related to north-westward flowing meltwater from the glacier as it stood at the Paris and Galt moraines respectively with the quiet period representing the time of retreat between the moraines. Subsequent melting to the north initiated an ice-contact spillway which ended the outwash deposition west or Galt. </p> / Thesis / Bachelor of Science (BSc)

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