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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.
11

An improved feature extractor for the lidar odometry and mapping algorithm

Gonzalez Cadenillas, Clayder Alejandro January 2019 (has links)
Tesis para optar al grado de Magíster en Ciencias de la Ingeniería, Mención Eléctrica / La extracción de características es una tarea crítica en la localización y mapeo simultáneo o Simultaneous Localization and Mapping (SLAM) basado en características, que es uno de los problemas más importantes de la comunidad robótica. Un algoritmo que resuelve SLAM utilizando características basadas en LiDAR es el algoritmo LiDAR Odometry and Mapping (LOAM). Este algoritmo se considera actualmente como el mejor algoritmo SLAM según el Benchmark KITTI. El algoritmo LOAM resuelve el problema de SLAM a través de un enfoque de emparejamiento de características y su algoritmo de extracción de características detecta las características clasifican los puntos de una nube de puntos como planos o agudos. Esta clasificación resulta de una ecuación que define el nivel de suavidad para cada punto. Sin embargo, esta ecuación no considera el ruido de rango del sensor. Por lo tanto, si el ruido de rango del LiDAR es alto, el extractor de características de LOAM podría confundir los puntos planos y agudos, lo que provocaría que la tarea de emparejamiento de características falle. Esta tesis propone el reemplazo del algoritmo de extracción de características del LOAM original por el algoritmo Curvature Scale Space (CSS). La elección de este algoritmo se realizó después de estudiar varios extractores de características en la literatura. El algoritmo CSS puede mejorar potencialmente la tarea de extracción de características en entornos ruidosos debido a sus diversos niveles de suavizado Gaussiano. La sustitución del extractor de características original de LOAM por el algoritmo CSS se logró mediante la adaptación del algoritmo CSS al Velodyne VLP-16 3D LiDAR. El extractor de características de LOAM y el extractor de características de CSS se probaron y compararon con datos reales y simulados, incluido el dataset KITTI utilizando las métricas Optimal Sub-Pattern Assignment (OSPA) y Absolute Trajectory Error (ATE). Para todos estos datasets, el rendimiento de extracción de características de CSS fue mejor que el del algoritmo LOAM en términos de métricas OSPA y ATE.
12

The effect of nitrate of soda, sulphate of ammonia and calcium cyanamid on the base-exchange properties of berks silt loam

LaMarre, Francis H. January 1945 (has links)
M.S.
13

Comparative effect of various nitrogenous fertilizers on soil reaction and soil aggregation of different Simcoe soils.

Haque, Ihsan-ul January 1968 (has links)
During 1967-68 experiments to determine the comparative effect of various nitrogenous fertilizers on soil reaction and soil aggregation of the Fox sandy loam, the Lincoln loam and the Lincoln clay loam were carried out in the pedology Laboratory of the Department of Geography, McMaster University. The soil samples were taken from the Horticultural Experiment Station, Simcoe, Ontario. A review of literature is presented in Chapter II. Chapter III discusses experimental techniques, results and a discussion of problems encountered. Chapter IV summarizes the results of the survey and analyses. / Thesis / Master of Arts (MA)
14

Data reduction methods for field estimated hydraulic properties

Salem, Salloum Berghooth. January 1986 (has links)
Call number: LD2668 .T4 1986 S237 / Master of Science / Agronomy
15

The nature of ochre deposition and drain blockage in a fine sandy loam soil.

Gameda, S. January 1981 (has links)
No description available.
16

Lime and fertilizer incorporation in Spencer soils for alfalfa production [I.] II. Downward movement of calcium, magnesium, and potassium in Spencer, Almena, and Antigo silt loam soils under field conditions /

Love, James R. January 1956 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1956. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
17

Soil surface-seal measurement using high-resolution x-ray computed tomography (HRCT)

Lee, Sang Soo, January 2006 (has links)
Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 24, 2007) Vita. Includes bibliographical references.
18

The nature of ochre deposition and drain blockage in a fine sandy loam soil.

Gameda, S. January 1981 (has links)
No description available.
19

The Character and Origin of the Soil Tongues in the Burford Loam / Soil Tongues In The Burford Loam

Grubb, Alquin Meirion Jacob 04 1900 (has links)
<p> A pedological investigation was made of the soil tongues in the Burford loam soils of S. W. Ontario. The purpose of the study was to determine the characteristic features of the soil tongues. The physical and chemical properties of a number of soil tongues were determined and one was used for a micromorphological investigation. Measurements of horizontal and vertical extent were also made. Discussion of the various hypotheses that might account for soil tongue development is included. Evidence for a periglacial climate is given and also f'or the existence of two distinct types of soil tongues. </p> / Thesis / Master of Science (MSc)
20

A study of trends in yields of crops grown in rotation, the residual effects of fertilizer applications, and the relationship between plant food removed and that added on Dunmore silt loam soil

Hawkins, Barney Stewart January 1940 (has links)
Master of Science

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