Academic literature on the topic 'Amplitude and height parameters'

The thesis deals with an evaluation of the surface texture of various materials, created by machining technologies (turning, milling and grinding). As for the theoretical part of the thesis, it contains a theoretical analysis of the effect of surface texture on friction, wear, coating and lubricating properties. The main emphasis is put on the analysis of the most frequently evaluated profile and surface parameters as well as their possible influence on the functional areas of machined parts. The experimental part includes evaluated and compared measured data based on the monitored parameters with benefits for machinery industry.

The diploma thesis deals with the influence of machining technologies (turning, milling, grinding and polishing) on the surface texture of functional surfaces of selected materials from technical plastics. In the first part of the thesis there is a theoretical analysis of the possibilities of machining plastic materials. Furthermore, an analysis of the most commonly used parameters for evaluating the roughness of the machined surface and their effect on functionality is performed. The experimental part of the thesis describes samples preparation, analysis of measured data and subsequent evaluation with benefits for machinery industry.

Airborne CW doppler proximity sensors are very sensitive, but leaks precise height measurement. It may be possible to estimate the heigth at the terminal phase (the case where the sensor is at a heigth close to ground) precisely by using the doppler shift and amplitude information. The thesis includes this novel concept with theoritical analysis and simulation results.

The objective of this study is to investigate a large network of GPS stations to identify and analyze spatially coherent signals present in the Up coordinate time series of the stations and, at the same locations, to identify and analyze common patterns in the series of environmental parameters and climate indices. The study is confined to Europe and the Mediterranean area, where 107 GPS sites were selected from the archive of the Nevada Geodetic Laboratory (NGL) on the basis of the completeness and length of the data series. The parameters of interest the Up coordinate of the GPS stations, the surface pressure (SP), the terrestrial water storage (TWS) and various climate indices: NAO (North Atlantic Oscillation), EA (East Atlantic), AO (Artic Oscillation), SCAND (Scandinavia), TNA (Tropical North Atlantic) and MEI v2 (Multivariate ENSO Index version 2). The Principal Component Analysis (PCA) is the methodology adopted to extract the main patterns of the space/time variability of these parameters. The work also focused on the coupled modes of space/time interannual variability between pairs of variables using the Singular Value Decomposition (SVD) methodology. The coupled variability between all the aforementioned parameters is investigated. This study has identified, over Europe and the Mediterranean, main modes of variability in the time series of the GPS Up coordinate, SP and TWS. The SVD analysis of coupled parameters, namely GPS Up-SP and GPS Up-TWS, showed that most of the common variability is explained by the first 3 modes. Moreover, the correlation between the GPS Up coordinate and the climate indices was estimated to investigate the possible influence of climate variability on the GPS Up behaviour. More than 30 stations, over the total of 107, show significant correlations with the AO, TNA and SCAND indices. The correlation coefficients with MEI v2 turn out to be significant and up to 0.5 for about half of the stations.

Carbon nanotube forests (CNTFs) are grown using an injection chemical vapor deposition method. Images of CNTFs are taken using a scanning electron microscope and are used to measure their height and density. Growth parameters are systematically varied to determine their effect on the height and density of CNTFs. Investigations of CNTF density as a function of distance from the growth substrate reveal that diffusion can be a limiting factor on CNTF growth. Our findings indicate that height and density are related and that each growth parameter has multi-dimensional effects.

The main study objective was to develop robust processing and analysis techniques to facilitate the use of small-footprint lidar data for estimating forest biophysical parameters measuring individual trees identifiable on the three-dimensional lidar surface. This study derived the digital terrain model from lidar data using an iterative slope-based algorithm and developed processing methods for directly measuring tree height, crown diameter, and stand density. The lidar system used for this study recorded up to four returns per pulse, with an average footprint of 0.65 m and an average distance between laser shots of 0.7 m. The lidar data set was acquired over deciduous, coniferous, and mixed stands of varying age classes and settings typical of the southeastern United States (37° 25' N, 78° 41' W). Lidar processing techniques for identifying and measuring individual trees included data fusion with multispectral optical data and local filtering with both square and circular windows of variable size. The window size was based on canopy height and forest type. The crown diameter was calculated as the average of two values measured along two perpendicular directions from the location of each tree top, by fitting a four-degree polynomial on both profiles. The ground-truth plot design followed the U.S. National Forest Inventory and Analysis (FIA) field data layout. The lidar-derived tree measurements were used with regression models and cross-validation to estimate plot level field inventory data, including volume, basal area, and biomass. FIA subplots of 0.017 ha each were pooled together in two categories, deciduous trees and pines. For the pine plots, lidar measurements explained 97% of the variance associated with the mean height of dominant trees. For deciduous plots, regression models explained 79% of the mean height variance for dominant trees. Results for estimating crown diameter were similar for both pines and deciduous trees, with R2 values of 0.62-0.63 for the dominant trees. R2 values for estimating biomass were 0.82 for pines (RMSE 29 Mg/ha) and 0.32 for deciduous (RMSE 44 Mg/ha). Overall, plot level tree height and crown diameter calculated from individual tree lidar measurements were particularly important in contributing to model fit and prediction of forest volume and biomass.<br>Ph. D.