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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.
351

Tile-based methods for online choropleth mapping: a scalability evaluation

January 2013 (has links)
abstract: Choropleth maps are a common form of online cartographic visualization. They reveal patterns in spatial distributions of a variable by associating colors with data values measured at areal units. Although this capability of pattern revelation has popularized the use of choropleth maps, existing methods for their online delivery are limited in supporting dynamic map generation from large areal data. This limitation has become increasingly problematic in online choropleth mapping as access to small area statistics, such as high-resolution census data and real-time aggregates of geospatial data streams, has never been easier due to advances in geospatial web technologies. The current literature shows that the challenge of large areal data can be mitigated through tiled maps where pre-processed map data are hierarchically partitioned into tiny rectangular images or map chunks for efficient data transmission. Various approaches have emerged lately to enable this tile-based choropleth mapping, yet little empirical evidence exists on their ability to handle spatial data with large numbers of areal units, thus complicating technical decision making in the development of online choropleth mapping applications. To fill this knowledge gap, this dissertation study conducts a scalability evaluation of three tile-based methods discussed in the literature: raster, scalable vector graphics (SVG), and HTML5 Canvas. For the evaluation, the study develops two test applications, generates map tiles from five different boundaries of the United States, and measures the response times of the applications under multiple test operations. While specific to the experimental setups of the study, the evaluation results show that the raster method scales better across various types of user interaction than the other methods. Empirical evidence also points to the superior scalability of Canvas to SVG in dynamic rendering of vector tiles, but not necessarily for partial updates of the tiles. These findings indicate that the raster method is better suited for dynamic choropleth rendering from large areal data, while Canvas would be more suitable than SVG when such rendering frequently involves complete updates of vector shapes. / Dissertation/Thesis / Ph.D. Geography 2013
352

Physical Mapping of Human Transfer RNA Gene Clusters

Wang, Luping 12 1900 (has links)
Two plaque-pure phage lambda clones designated as λhtX-l and λhtX-2 that hybridized to unfractionated bovine liver tRNA were isolated from a human X chromosome-specific library. The λDNAs were characterized by restriction mapping and Southern blot hybridization techniques. The human DNA segment in λhtX-l contains five or more presumptive tRNA genes and at least one Alu family member. The 19-kilobase human DNA insert in λhtX-2 contains two or more presumptive tRNA genes and at least three Alu family members. Another human genomic clone designated λhVKV7 hybridized to mammalian valine tRNA IAC. The clone was characterized by physical mapping and Southern blot hybridization techniques. The 18.5-kilobase human DNA fragment in λhVKV7 contains a cluster of three tRNA genes and at least nine Alu family members.
353

Novel methods for increasing efficiency of quantitative trait locus mapping

Guo, Zhigang January 1900 (has links)
Doctor of Philosophy / Department of Plant Pathology / James C. Nelson / The aim of quantitative trait locus (QTL) mapping is to identify association between DNA marker genotype and trait phenotype in experimental populations. Many QTL mapping methods have been developed to improve QTL detecting power and estimation of QTL location and effect. Recently, shrinkage Bayesian and penalized maximum-likelihood estimation approaches have been shown to give increased power and resolution for estimating QTL main or epistatic effect. Here I describe a new method, shrinkage interval mapping, that combines the advantages of these two methods while avoiding the computing load associated with them. Studies based on simulated and real data show that shrinkage interval mapping provides higher resolution for differentiating closely linked QTLs and higher power for identifying QTLs of small effect than conventional interval-mapping methods, with no greater computing time. A second new method developed in the course of this research toward increasing QTL mapping efficiency is the extension of multi-trait QTL mapping to accommodate incomplete phenotypic data. I describe an EM-based algorithm for exploiting all the phenotypic and genotypic information contained in the data. This method supports conventional hypothesis tests for QTL main effect, pleiotropy, and QTL-by-environment interaction. Simulations confirm improved QTL detection power and precision of QTL location and effect estimation in comparison with casewise deletion or imputation methods.
354

Nanotribological investigations of materials, coatings and lubricants for nanotechnology applications at high sliding velocities

Tambe, Nikhil S. 09 March 2005 (has links)
No description available.
355

Review of Displacement Mapping Techniques and Optimization / Granskning av Displacement Mapping Tekniker och Optimering

Lundgren, Mikael, Hrkalovic, Ermin January 2012 (has links)
This paper explores different bump mapping techniques and their implementation. Bump mapping is a technique that is used in computer games to make simple 3D objects look more detailed than what they really are. The technique involves using a texture to change the objects normals to simulate bumps and is used to avoid rendering high polygonal objects. Over the years some different techniques have been developed based on bump mapping, these are normal mapping, relief mapping, parallax occlusion mapping, quadtree displacement mapping and so on. The first part of this paper we go through our goals and our research methodology. We then write about four different techniques and describe how they work. We also go through how they are implemented. After that we start our experiments and measure the different techniques against each other. When the first testing has been done, we start to optimize the techniques and run a second test to see how much faster, if it is faster, the optimization is compared to the previous tests. When the tests are done, we present our test data and analyse them. Finally we discuss the techniques and the testing. Then we finish up with a conclusion. / Mikaels telefon: 072-181 77 29 Ermins telefon: 076-178 97 59
356

Computational and experimental methods in functional genomics : the good, the bad, and the ugly of systems biology

Hart, Glen Traver 01 October 2012 (has links)
Seven years into the postgenomic era, we sit atop a mountain of data whose generation was enabled by gene sequencing. The creation, integration, and analysis of these large scale data sets allow us to move forward toward the complementary goals of determining the individual roles of the thousands of uncharacterized mammalian genes and understanding how they work together to produce a healthy human being -- or, perhaps more importantly, how their malfunction results in disease. Collapsing the results of large-scale assays into gene networks provides a useful framework from which we can glean information that advances both of these goals. However, the utility of networks is limited by the quality of the data that goes into them. This study offers seeks to shed some light on the quality and breadth of protein interaction networks, describes a new experimental technique for functional genetic assays in mammalian cell lines, and ultimately suggests a strategy for how to improve the overall utility of the output generated by the systems biology community. / text
357

Hybrid image classification technique for land-cover mapping in the arctic tundra, North Slope, Alaska

Chaudhuri, Debasish. January 1900 (has links)
Dissertation (Ph.D.)--The University of North Carolina at Greensboro, 2008. / Title from PDF t.p. (viewed Aug. 10, 2009). Directed by Roy Stine; submitted to the Dept. of Geography. Includes bibliographical references (p. 154-165).
358

Different Mapping Techniques for Realistic Surfaces

Öhrn, Kristina January 2008 (has links)
The different mapping techniques that are used increases the details on surfaces without increasing the number of polygons. Image Based Sculpting tools in the program Modo and Z-Brush is used to create folds and wrinkles from photographs of actual fabrics instead of trying to create these shapes by modeling them. This method makes it easier to achieve photorealistic renderings and produce as realistic fabric dynamics as possible when they are applied on objects.
359

Algoritmy a metody pro fúzi dat maticových snímačů při mapování interiéru budovy / Algorithms and Methods for Fusion of Matrix Sensors Data during Mapping Inside Building

Klečka, Jan January 2020 (has links)
The dissertation is aimed at methods for simultaneous processing of various type sensor data into a virtual map. Conceptually the development was focused on algorithms for simultaneous localization and mapping. In theoretical part has the problem been addressed by the probabilistic approach. The practical part deals with a new approach called as partially collective mapping whose application leads to creation map in form of a set of simple geometrical entities which represents in piecewise manner a border between obstacles and free space.
360

The Effect of Information Structuring on Analytical Knowledge Acquisition

Al-Gharaibeh, Rami Salah 18 July 2007 (has links)
No description available.

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