High-accuracy density measurement data are required to validate equations of state (EOS) for use in custody transfer of natural gas through pipelines. The AGA8-DC92 EOS, which is the current industry standard has already been validated against a databank of natural gas mixtures with compositions containing up to 0.2 mole percent of the heavier C6+ fraction and is expected to predict densities of natural gas mixtures containing higher mole percentages of the C6+ fraction with the same accuracy. With the advances in exploration, drilling and production, natural gas streams containing higher percentages of the C6+ fraction have become available from the deepwater and ultra-deepwater Gulf of Mexico in recent years. High-accuracy, density data for such natural gas mixtures are required to check if the AGA8-DC92 EOS covers the entire range of pressure, temperature and compositions encountered in custody transfer. A state-of-the-art, high pressure, high temperature, compact single-sinker magnetic suspension densitometer has been used to measure densities of two simulated natural gas mixtures named M91C1 and M94C1 after validating its operation by measuring densities of pure argon, nitrogen and methane in the range (270 to 340) K [(26.33 to152.33) oF, (-3.15 to 66.85) oC] and (3.447 to 34.474) MPa [(500 to 5,000) psia]. Measured densities of M91C1, not containing the C6+ fraction show larger than expected relative deviations from the AGA8-DC92 EOS predictions in regions 1 and 2 but agree well with predictions from the recently developed REFPROP EOS, implyingthat the AGA8-DC92 EOS may be unreliable in its present state even for natural gas mixtures not containing the C6+ fraction. Measured densities of M94C1 containing more than 0.2 mole percent of the C6+ fraction deviate from the AGA8-DC92 EOS predictions by more than the expected values in region 1 which is not surprising but the agreement with AGA8-DC92 EOS predictions in region 2 is misleading which becomes evident when the measured densities are compared to the REFPROP EOS predictions. The measured data can be used to recalibrate the parameters of the AGA8-DC92 EOS or to validate an entirely new EOS.

Natural Gas (NG) plays an important role in the energy demand in the United States and throughout the world. Its characteristics as a clean, versatile and a sustainable source of energy makes it an important alternative within the spectra of energy resources. Addressing industrial and academic needs in the natural gas research area requires an integrated plan of research among experimentation, modeling and simulation. In this work, high accuracy PpT data have been measured with a high pressure single sinker magnetic suspension densimeter. An entire uncertainty analysis of this apparatus reveals that the uncertainty of the density data is less that 0.05% across the entire ranges of temperature (200 to 500) K and pressure (up to 200 MPa). These characteristics make the PpT data measured in this study unique in the world. Additionally, both a low pressure (up to 35 MPa) and a high pressure (up to 200 MPa) isochoric apparatus have been developed during the execution of this project. These apparatuses, in conjunction with a recently improved isochoric technique, allow determination of the phase envelope for NG mixtures with an uncertainty of 0.45% in temperature, 0.05% in pressure and 0.12% in density. Additionally, an innovative technique, based upon Coherent Anti-Stokes Raman Scattering (CARS) and Gas Chromatography (GC), was proposed in this research to minimize the high uncertainty introduced by the composition analyses of NG mixtures. The collected set of P?T and saturation data are fundamental for thermodynamic formulations of these mixtures. A study at the molecular level has provided molecular data for a selected set of main constituents of natural gas. A 50-50% methane-ethane mixture was studied by molecular dynamics simulations. The result of this study showed that simulation time higher than 2 ns was necessary to obtain reasonable deviations for the density determinations when compared to accurate standards. Finally, this work proposed a new mixing rule to incorporate isomeric effects into cubic equations of state.

The theory of non-orthogonal spin-adaptation for closed-shell molecular systems is presented, with an emphasis on application to the coupled cluster family of electronic structure methods. To aid in the derivation of efficient and compact working equations, a new diagrammatic interpretation of the Goldstone diagrams is derived which only requires a small number of the many distinct diagrams and which directly produces equations in a factored form in terms of “spin-summed” tensor elements. This diagrammatic interpretation is applied to coupled cluster methods with quadruple excitations (CCSDTQ), including coupled cluster with a perturbative correction for quadruple excitations (CCSDT(Q)) and to CCSDTQ gradients and properties. The advantages of the non-orthogonal spin-adaption with respect to simplification and factorization of the working equations and to efficient implementation are presented and discussed. Additionally, specific optimizations of the implementation for often-overlooked issues such as tensor transposition, disk access, and removal of redundant and/or unnecessary operations are detailed. The resulting algorithm is implemented for the CCSDTQ and CCSDT(Q) methods and compared to existing codes, where a one to two order-of-magnitude improvement in efficiency is observed. The new implementation is also used for calculations on several larger molecular systems to illustrate the scalability of the method. / text

Industrial applications increasingly require actuators that offer a combination of high force output, large stroke and high accuracy. The ElectroHydraulic Actuator (EHA) was designed by Drs. Habibi and Goldenberg originally as a high-performance actuator for use in robotics. However, it was determined that the EHA had the potential to achieve high positional accuracy. Little research has been performed in the area of high-accuracy hydraulic positioning systems. Therefore, the objective of this study to achieve nano-scale positional accuracy with the EHA while maintaining large stroke and high force output. It was planned to achieve this objective through modification of the prototype EHA and the use of fuzzy control. During this research project, both hardware and control system modifications to the EHA were performed. A high-precision optical encoder position sensor with a 50 nm resolution was mounted on the inertial load to directly measure the position of the load. A number of device drivers were written to interface the MATLAB real-time control environment with the optical encoder and servo motor amplifier. A Sugeno-inference fuzzy controller was designed and implemented in MATLAB. For comparison purposes, a switched-gain controller and a proportional controller were also implemented in the control environment. The performance of the fuzzy controller was compared to the switched-gain controller and the proportional controller in a number of tests. First, the regulatory and tracking performance of the EHA with an inertial load of 20 kg was examined. It was determined in the regulatory tests that the positional accuracy of the EHA with the fuzzy controller was excellent, achieving a steady state error of 50 ± 25 nm or less for step inputs in the range 5 cm to 200 nm. The positional accuracy during the tracking tests was found to be reduced compared to the regulatory tests since the actuator did not have sufficient time to settle to final accuracy due to the timevarying input signals. In all cases, it was found that the positional accuracy of the EHA with the fuzzy controller was significantly greater than with the switched-gain and proportional controllers for both regulatory and tracking signals. Testing with the inertial load eliminated or changed was not performed because the position sensor was mounted to the load, making it unfeasible to alter the load during the time frame of this study. The regulatory and tracking performance of the EHA with an inertial load of 20 kg plus external resistive loads of 90 to 280 N were investigated. It was found that the positional accuracy of the EHA decreased with the application of an external load to 3.10 ± 0.835 µm for a 1 cm step input (90 N load) and 8.45 ± 0.400 µm for a 3 cm step input (280 N load). Again, the positional accuracy of the EHA decreased during the tracking tests relative to the regulatory tests, for the reason stated above. This implies that the positional accuracy of the EHA with a resistive load is in the microscale, rather than the nano-scale as was put forth as the objective of this study. Nevertheless, the positional accuracy of the EHA with the fuzzy controller was found to be significantly greater than with the switched-gain and proportional controllers. It is postulated that the increase in positional error observed during the external load tests was due to an increase in cross-port leakage, relative to the inertial load tests, caused by the pressure differential induced across the actuator by the external load. Methods of reducing the increase in positional error caused by external loads on the EHA remains an area for future study.

Industrial applications increasingly require actuators that offer a combination of high force output, large stroke and high accuracy. The ElectroHydraulic Actuator (EHA) was designed by Drs. Habibi and Goldenberg originally as a high-performance actuator for use in robotics. However, it was determined that the EHA had the potential to achieve high positional accuracy. Little research has been performed in the area of high-accuracy hydraulic positioning systems. Therefore, the objective of this study to achieve nano-scale positional accuracy with the EHA while maintaining large stroke and high force output. It was planned to achieve this objective through modification of the prototype EHA and the use of fuzzy control. During this research project, both hardware and control system modifications to the EHA were performed. A high-precision optical encoder position sensor with a 50 nm resolution was mounted on the inertial load to directly measure the position of the load. A number of device drivers were written to interface the MATLAB real-time control environment with the optical encoder and servo motor amplifier. A Sugeno-inference fuzzy controller was designed and implemented in MATLAB. For comparison purposes, a switched-gain controller and a proportional controller were also implemented in the control environment. The performance of the fuzzy controller was compared to the switched-gain controller and the proportional controller in a number of tests. First, the regulatory and tracking performance of the EHA with an inertial load of 20 kg was examined. It was determined in the regulatory tests that the positional accuracy of the EHA with the fuzzy controller was excellent, achieving a steady state error of 50 ± 25 nm or less for step inputs in the range 5 cm to 200 nm. The positional accuracy during the tracking tests was found to be reduced compared to the regulatory tests since the actuator did not have sufficient time to settle to final accuracy due to the timevarying input signals. In all cases, it was found that the positional accuracy of the EHA with the fuzzy controller was significantly greater than with the switched-gain and proportional controllers for both regulatory and tracking signals. Testing with the inertial load eliminated or changed was not performed because the position sensor was mounted to the load, making it unfeasible to alter the load during the time frame of this study. The regulatory and tracking performance of the EHA with an inertial load of 20 kg plus external resistive loads of 90 to 280 N were investigated. It was found that the positional accuracy of the EHA decreased with the application of an external load to 3.10 ± 0.835 µm for a 1 cm step input (90 N load) and 8.45 ± 0.400 µm for a 3 cm step input (280 N load). Again, the positional accuracy of the EHA decreased during the tracking tests relative to the regulatory tests, for the reason stated above. This implies that the positional accuracy of the EHA with a resistive load is in the microscale, rather than the nano-scale as was put forth as the objective of this study. Nevertheless, the positional accuracy of the EHA with the fuzzy controller was found to be significantly greater than with the switched-gain and proportional controllers. It is postulated that the increase in positional error observed during the external load tests was due to an increase in cross-port leakage, relative to the inertial load tests, caused by the pressure differential induced across the actuator by the external load. Methods of reducing the increase in positional error caused by external loads on the EHA remains an area for future study.

In this dissertation recent advances in modeling various atomic and molecular systems with quantum mechanical calculations employing explicitly correlated Gaussian functions are presented. The author has utilized multiple approaches and considered a number of approximations to develop optimal calculation frameworks. Electronic and muonic molecules and atoms have been considered. A number of unique calculations have been performed and some novel and interesting results, including high accuracy description of the charge asymmetry in the heteronuclear systems and lifetimes of rotationless vibrational levels of diatomic molecules, have been generated.

Acquisition of 3D model of real objects and scenes is indispensable and useful in many practical applications, such as digital archives, game and entertainment industries, engineering, advertisement. There are 2 main methods for 3D acquisition : laser-based reconstruction (active method) and image-based reconstruction from multiple images of the scene in different points of view (passive method). While laser-based reconstruction achieves high accuracy, it is complex, expensive and difficult to set up for large-scale outdoor reconstruction. Image-based, or multi-view stereo methods are more versatile, easier, faster and cheaper. By the time we begin this thesis, most multi-view methods could handle only low resolution images under controlled environment. This thesis targets multi-view stereo both both in large scale and high accuracy issues. We significantly improve some previous methods and combine them into a remarkably effective multi-view pipeline with GPU acceleration. From high-resolution images, we produce highly complete and accurate meshes that achieve best scores in many international recognized benchmarks. Aiming even larger scale, on one hand, we develop Divide and Conquer approaches in order to reconstruct many small parts of a big scene. On the other hand, to combine separate partial results, we create a new merging method, which can merge automatically and quickly hundreds of meshes. With all these components, we are successful to reconstruct highly accurate water-tight meshes for cities and historical monuments from large collections of high-resolution images (around 1600 images of 5 M Pixel images)

Acquisition of 3D model of real objects and scenes is indispensable and useful in many practical applications, such as digital archives, game and entertainment industries, engineering, advertisement. There are 2 main methods for 3D acquisition : laser-based reconstruction (active method) and image-based reconstruction from multiple images of the scene in different points of view (passive method). While laser-based reconstruction achieves high accuracy, it is complex, expensive and difficult to set up for large-scale outdoor reconstruction. Image-based, or multi-view stereo methods are more versatile, easier, faster and cheaper. By the time we begin this thesis, most multi-view methods could handle only low resolution images under controlled environment. This thesis targets multi-view stereo both both in large scale and high accuracy issues. We significantly improve some previous methods and combine them into a remarkably effective multi-view pipeline with GPU acceleration. From high-resolution images, we produce highly complete and accurate meshes that achieve best scores in many international recognized benchmarks. Aiming even larger scale, on one hand, we develop Divide and Conquer approaches in order to reconstruct many small parts of a big scene. On the other hand, to combine separate partial results, we create a new merging method, which can merge automatically and quickly hundreds of meshes. With all these components, we are successful to reconstruct highly accurate water-tight meshes for cities and historical monuments from large collections of high-resolution images (around 1600 images of 5 M Pixel images)

GNSS positioning has become a key element in everyday life of millions of people, from the person using google maps to move around an unknown city to the mailman or the DRON pilot who require it to carry out their work. All of them benefit in some way from the GNSS constellations and the position algorithms.The European Union through their GNSS constellation, Galileo, has recently made available a new service called Galileo High Accuracy Service (HAS). With the aim of improving the positioning solutions already provided by the Open Service (OS) to a centimetric level with the target of professional and commercial users requiring this high accuracy. As a result, in this Master Thesis project the steps of the development and implementation of a Software-Defined Radio to collect the High Accuracy corrections transmitted through Galileo GNSS constellation are going to be shown. The SDR itself is going to be made available so that other persons from companies to academia can benefit from it and see how the corrections are extracted and either use the algorithm or implement its own to be able to use this High Accuracy Service.

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