abstract: Conformance of a manufactured feature to the applied geometric tolerances is done by analyzing the point cloud that is measured on the feature. To that end, a geometric feature is fitted to the point cloud and the results are assessed to see whether the fitted feature lies within the specified tolerance limits or not. Coordinate Measuring Machines (CMMs) use feature fitting algorithms that incorporate least square estimates as a basis for obtaining minimum, maximum, and zone fits. However, a comprehensive set of algorithms addressing the fitting procedure (all datums, targets) for every tolerance class is not available. Therefore, a Library of algorithms is developed to aid the process of feature fitting, and tolerance verification. This paper addresses linear, planar, circular, and cylindrical features only. This set of algorithms described conforms to the international Standards for GD&T.; In order to reduce the number of points to be analyzed, and to identify the possible candidate points for linear, circular and planar features, 2D and 3D convex hulls are used. For minimum, maximum, and Chebyshev cylinders, geometric search algorithms are used. Algorithms are divided into three major categories: least square, unconstrained, and constrained fits. Primary datums require one sided unconstrained fits for their verification. Secondary datums require one sided constrained fits for their verification. For size and other tolerance verifications, we require both unconstrained and constrained fits / Dissertation/Thesis / M.S. Mechanical Engineering 2014

This thesis describes an attempt to devise a human comfort climatology of the British Isles using social survey methods, and, as such is a departure from previous work which used either controlled experiments or simplified energy balance models. A Likert scale questionnaire was administered to 750 people in a street survey in order to elicit their views of the weather, and its results related to the measured weather. The response was found to be related to a linear combination of the Windchill and Temperature Humidity Indices, cloud cover, pressure and presence or absence of precipitation. This 'Index of Human Comfort' was calculated for the synoptic stations using a sample of U.K. Daily Weather Report data with the data being stratified according to the Lamb Natural Seasons. These data are instantaneous recordings and as such reflected the true covariance of the data unlike mean data which have been used in most earlier work. The examination of the spatial and temporal variation in the mean and standard deviation of the Index of Human Comfort revealed distinct seasonal differences although latitude and proximity to the coast were important controls in all seasons with Southern inland areas being the most favoured for human comfort. The use of instantaneous data also allowed a consideration of the maxima and minima of the Index and its range which again revealed a North to South and coast to inland improvement in human comfort. The thesis concludes with some recommendations for future research which include the need for the development of improved methodologies for the study of the relationship between man and weather and the ways in which a human comfort climatology can be derived, either indirectly by synthesis from an index of comfort, or directly by eliciting people's views on the climate rather than the weather.

The UK weather radar network and telemetry system for the raingauges and river level gauges provided the solid physical base which produce the large amount of data in real time and a large variety of operational flood forecasting models were supplied from SW Region of the Environment Agency. Data processing, the selection of a suitable model, model calibration and parameters updating have played a more and more important role in real time forecasting and this thesis focuses on many of the key issues involved in the emerging area. Within this context, surface fitting, interpolation and cluster analysis were used for adjustment of the weather radar data and comparison between the raingauge data and radar data. As the core of the forecasting system the rainfall runoff model and river routing model were investigated in a wide-ranging manner, the key model utilised is the Transfer Function model. Potential misinterpretation of the TF model was explained by distinguishing between the "Black Box" model and the "White Box" model. The physically based Genetic Cascade Transfer Function (GCTF) model was introduced and shown to be consistent with the Gamma function and Muskingum model which were based upon the three common assumptions: linear, time-invariant and Single Input Single Output (SISO) system. The calculation formula for the moment parameters and the geometry coefficients (t-peak time, volume parameter) create the initial model and a genetic algorithm provides the basic tool to global search for the parameters. An expert system plus the genetic algorithm are combined to provide a real time updating capability. A dentritic model composed of the SISO rainfall runoff model at several tributaries and the Multi-Input Single Output (MISO) routing model in the mainstream were developed and applied to the Bristol Avon catchment. As a Weather Radar Information Processor, WRIP(II) was extended and implemented on a SPARC 10 workstation and communions at Environment Agency South West Region (Exeter) with a graphical user interface based on X/Motif.

This thesis describes the development of real-time flood forecasting models at selected catchments in the three countries, using rain gauge and radar derived rainfall estimates and time-series analysis. An extended inter-comparison of real-time flood forecasting models has been carried out and an attempt has been made to rank the flood forecasting models. It was found that an increase in model complexity does not necessarily lead to an increase in forecast accuracy. An extensive analysis of group calibrated transfer function (TF) models on the basis of antecedent conditions of the catchment and storm characteristics has revealed that the use of group model resulted in a significant improvement in the quality of the forecast. A simple model to calculate the average pulse response has also been developed. The development of a hybrid genetic algorithm (HGA), applied to a physically realisable transfer function model is described. The techniques of interview selection and fitness scaling as well as random bit mutation and multiple crossover have been included, and both binary and real number encoding technique have been assessed. The HGA has been successfully applied for the identification and simulation of the dynamic TF model. Four software packages have been developed and extensive development and testing has proved the viability of the approach. Extensive research has been conducted to find the most important adjustment factor of the dynamic TF model. The impact of volume, shape and time adjustment factors on forecast quality has been evaluated. It has been concluded that the volume adjustment factor is the most important factor of the three. Furthermore, several attempts have been made to relate the adjustment factors to different elements. The interaction of adjustment factors has also been investigated. An autoregressive model has been used to develop a new updating technique for the dynamic TF model by the updating of the B parameters through the prediction of future volume adjustment factors over the forecast lead-time. An autoregressive error prediction model has also been combined with a static TF model. Testing has shown that the performance of both new TF models is superior to conventional procedures.

<p> This dissertation describes the acquisition and analysis of tropical wave cloudiness. Tropical wave positions for the years 2003 through 2013 were extracted via text mining, from the National Hurricane Center&rsquo;s Tropical Weather Discussion, a bulletin released every six hours and published on-line. Tropical wave tracks were developed from these positions using the Multiple Hypothesis Tracking algorithm. Satellite data from the Atmospheric Infrared Sounder (AIRS) was downloaded from the NASA Mirador website based on time and position of tracked tropical waves. The AIRS data was mosaicked to provide complete coverage between satellite swaths. The AIRS Level 2 Cloud Fraction Standard product was used exclusively in the analysis. Cloud fraction data was divided into upper and lower levels as provided in the AIRS product. A cloud fraction ratio was also developed to provide some indication of the insulating quality of clouds. The analysis discovered secular trends of varying degrees and direction depending on location of tropical waves. The analysis also found significant periodic variability within cloud fraction values, much of which correlated to known global oscillations such as El Nino and the Madden-Julian Oscillation. However a number of periodic signals found within tropical wave cloudiness could not be correlated with any of the known global and non-earth oscillations tested against. Future research ideas in the conclusions include an examination of those uncorrelated periodic signals. Also included in the conclusions are theories about differences in correlations to periodic signals within a tropical wave core versus correlations that are seen in surrounding cloud patterns.</p><p>

This study aims to advance our understanding of the inner-core dynamics of tropical cyclones (TCs) from the perspective of vortex Rossby waves (VRWs) through investigating wave kinematics, propagation feature, and wave-mean-flow interaction in three dimensional TC-like baroclinic vortices. Using the Wenzel-Kramers-Brillouin analysis in the asymmetric balanced model framework, the generalized wave dispersion relation, group velocities, and stagnation radius/height of VRW wave-packets in both pseudo-height and isentropic coordinates are derived. It is found that the VRW dispersion relation associated with baroclinic vortices in an isentropic coordinate has the same format as that of barotropic vortices in a pseudo-height coordinate. However, baroclinicity causes the vertical wavenumber to increase, resulting in wave propagation features different from those in barotropic vortices. The stagnation radius and height are strictly constrained by the geometry of the 'critical’ surface determined by the initial properties of wave-packets and basic-state vortices. Baroclinicity substantially promotes the vertical propagation of VRWs but suppresses the corresponding wave radial propagation under the constraint of the ‘critical’ surface. Asymmetries excited at the surface are trapped in the low layer with substantial radial propagation, whereas the waves excited in the low to mid-troposphere in the vortex inner-core region can effectively propagate upward but their radial propagation is suppressed. Only low azimuthal wavenumber asymmetries can have meaningful radial and vertical propagation. The theoretical prediction of wave kinematics is confirmed by the non-hydrostatic simulations performed by the Weather Research and Forecasting (WRF) model. The WRF simulations show that the VRWs in baroclinic vortices can be classified into a surface quasi-barotropic regime and an upper baroclinic regime. The distinct wave kinematics in these two regimes results in different wave-mean-flow interaction. The former causes a strong vortex spin-up just outside the center of the initial asymmetry similar to those in barotropic vortices, whereas the latter confines the mean angular momentum inside the center of initial asymmetry but substantially supports the upward transport of angular momentum. The vortex intensification in baroclinic vortices is shown to be governed by the tilting of wave phase, the radial and vertical eddy momentum fluxes, and the vortex symmetric response to asymmetric momentum forcing.

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