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Position estimation using only active phase voltage and current is presented to perform high accuracy position sensorless control of a SRM drive. By extracting the amplitude of the first switching harmonic terms of phase voltage and current for a PWM period through Fourier analysis, flux-linkage and position are estimated without external hardware circuitry such as a modulator and demodulator, resulting in increasing cost, as well as large position estimation error produced when the motional back emf is ignored near zero speed. Hence the proposed position estimation scheme covers the entire speed range including the standstill under various loads and it has high resolution information depending on switching frequency. Fourier series and Fast Fourier transform are employed to decompose the phase voltage and current into its first switching harmonic. A two-phase SRM drive system, consisting of an asymmetrical converter and a conventional closed-loop PI current controller, is utilized to validate the performance of the proposed position estimation scheme in comprehensive operating conditions. The estimated values very closely track the actual values in dynamic simulations and experiments. It is shown that the proposed position estimation scheme using Fourier analysis is sufficiently accurate and works satisfactorily at various operating points. This research also proposes an accurate self-inductance measurement method. In general, when applying circulating currents within the body of a ferromagnetic material under conditions of a time varying magnetic flux, the effects of eddy current losses and resistance changes due to heating decrease the magnetic field strength and thereby the reduced magnetic field decreases the magnetic flux-linkage of SRM. These losses make a challenge to the measurement of magnetic characteristics of SRM. These motives lead to propose a measurement methodology based on 60 Hz sinusoidal excitation using a variable AC power supply, which provides an alternative to time domain integration approaches for self-inductance or flux-linkage measurement as well as eliminates error arising from thermal and eddy currents effects. The validation of the proposed method is verified with the correlation between the measurement and FEA results of flux-linkage. Furthermore, this research proposes the solutions for low cost and high efficiency drive systems, consisting of a split AC converter and a two-phase SRM. Its performance is analyzed and verified with experiments at the rated speed under various loads. It is believed that this drive system combined with the proposed position estimation scheme using Fourier analysis is a strong contender to be a low cost motor drive system with single switch per phase having comparable efficiency and acoustic noise level as an asymmetric drive system. / Ph. D.

This thesis is about the development and performance enhancement of an induction motor electric vehicle drive system. The fundamental operation of the induction motor drive hardware and control software are introduced, and the different modulation techniques tested are described. A software simulation package is developed to assist in the control design and analysis of the drive system. Next, to establish the efficiency gains obtained by using space vector modulation in the improved drive system, an inverter with hysteresis current control is compared to the same inverter with space vector modulation in steady state and on separate driving profiles. A method for determining induction motor harmonic losses is introduced and is based on obtaining the phase current harmonics from sampled induction motor stator phase currents obtained. Using a semi-empirical loss model, the induction motor losses are compared between different pulse width modulation control strategies throughout the torque versus speed operating region. Next, several issues related to the robustness of the control design are addressed. To obtain good performance in the actual vehicle, a new method for driveline resonance compensation is developed and proven to work well through simulation and experiment. Lastly, this thesis discusses the development of a new method to compensate for the gain and phase error obtained in the feedback of the d-axis and q-axis stator flux linkages. Improved accuracy of the measured stator flux linkages will be shown to improve the field oriented controller by obtaining a more accurate measurement of the feedback electromagnetic torque. / Master of Science

Citrus es el género de la subfamilia Aurantioideae de mayor importancia económica. Su origen es la región sureste de Asia, en un área que incluye China, India y la península de Indochina y los archipiélagos de los alrededores. Aunque se han realizado múltiples estudios, la taxonomía del género Citrus aun no está bien definida, debido al alto nivel de diversidad morfológica encontrado en este grupo, la compatibilidad sexual entre sus especies y la apomixis de muchos genotipos. En la presente tesis doctoral se ha estudiado una amplia diversidad del género Citrus, especies relacionadas y otros taxones de la subfamilia Aurantioideae, para poder aclarar su organización y filogenia mediante el empleo de diferentes tipos de marcadores moleculares y métodos de genotipado. Más concretamente, el germoplasma de mandarino juega un papel muy importante en la mejora de variedades y patrones, pero su organización genética no está bien definida. Por lo tanto, se ha realizado un análisis en profundidad de su diversidad y organización genética. El desarrollo de marcadores moleculares de Inserción-Deleción (indel), por primera vez en cítricos, ha permitido demostrar su utilidad para estudios de diversidad y filogenia en el género Citrus. En combinación con los marcadores de tipo microsatélite (SSR), se ha cuantificado la contribución de los tres principales taxones de cítricos (C. reticulata, C. maxima and C. medica) a los genomas de las especies secundarias y cultivares modernos. También se ha definido su estructura genética a partir de los datos obtenidos en la secuenciación de 27 fragmentos de genes nucleares relacionados con la biosíntesis de compuestos que determinan la calidad de los cítricos y genes relacionados con la respuesta de la planta a estreses abióticos. El análisis de la filogenia nuclear ha permitido determinar la relación existente entre la especie C. reticulata y Fortunella, que se diferencian claramente del grupo formado por las otras dos principales especies de cítricos (C. maxima y C. medica). Este resultado está en concordancia con el origen geográfico de las especies estudiadas. A partir de este estudio, se han desarrollado marcadores moleculares de tipo SNP con un alto valor filogenético, que han sido transferidos a géneros relacionados de los cítricos. Estos marcadores han dado un resultado muy positivo en el género Citrus y serán de gran utilidad para el establecimiento de la huella genética del germoplasma en un nivel de diversidad más amplio. Se ha estudiado la organización genética dentro del germoplasma mandarino (198 genotipos de tipo mandarino pertenecientes a dos colecciones, INRA-CIRAD e IVIA), así como la introgresión de otros genomas mediante el uso de 50 y 24 marcadores de tipo SSR y indel, respectivamente, además de cuatro marcadores InDel mitocondrial (ADNmt). Se ha observado que muchos genotipos, que se creía que eran mandarinos puros, presentan introgresión de otros genomas ancestrales. Dentro del germoplasma de mandarino, se han identificado a nivel nuclear cinco grupos parentales, a partir de los cuales se originaron muchos genotipos, dando lugar a estructuras hibridas complejas. Se ha observado incluso, genotipos con un origen maternal no mandarino, determinado por los marcadores de ADNmt. La presente tesis doctoral ha aportado nueva información sobre las relaciones filogenéticas entre las especies del género Citrus, géneros cercanos, así como de las especies secundarias. Además, se han desarrollado nuevos marcadores moleculares que se complementan entre sí. Se ha establecido una nueva organización genética del germoplasma mandarino y se han caracterizado adecuadamente las dos colecciones de cítricos en estudio. Por lo tanto, todas estas contribuciones, ayudarán a los programas de mejora para la obtención de nuevas variedades de cítricos de alta calidad y permitirán optimizar la conservación y uso de los recursos genéticos existentes, así como su caracterización genética y fenotípica. / García Lor, A. (2013). Organización de la diversidad genética de los cítricos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/31518

Disease resistance is critical in soft red winter wheat (Triticum aestivum L.) cultivars. Leaf rust caused by Puccinia triticina Eriks and stripe rust caused by Puccinia striiformis Westend. f.sp. tritici Eriks. are destructive pathogens of wheat. From 2014 to 2015 phenotypic data was collected at diverse locations for resistance to leaf rust (North Carolina, Texas, and Virginia) and stripe rust (Arkansas, North Carolina, Georgia, Texas, and Virginia) in a Pioneer ‘25R47’ /‘Jamestown’ (P47/JT) population composed of 186 F5:9 recombinant inbred lines (RILs). Analysis of the P47/JT population identified two quantitative trait loci (QTL) for leaf rust resistance on chromosome 5B and two QTL for stripe rust resistance on chromosomes 3B and 6A. Phenotypic variation (%) explained by the putative leaf rust resistance QTL of Jamestown on 5B was as high as 22.1%. Variation explained by the putative stripe rust resistance QTL of Jamestown on 3B and 6A was as high as 11.1 and 14.3%, respectively. Jamestown is postulated to contain gene Lr18. Seedlings of 186 F5:9 recombinant inbred lines from the P47/JT population and 200 F2 seedlings from eight other crosses including Jamestown and/or the Lr18 host differential line RL6009 (Thatcher*6/Africa 43) were screened with P. triticina race TNRJJ. Genetic analysis of the populations was conducted to validate the presence of Lr18 in Jamestown. Results of linkage analysis identified SNP maker IWB41960 linked within 5 cM of gene Lr18 in all three populations. From 2016 to 2017 phenotypic data was collected at diverse locations for resistance to leaf rust (Illinois, North Carolina, and Virginia) in a ‘2013412’ (PI 667644) / VA10W-21 (PI 676295) population (412/21) composed of 157 doubled haploid (DH) lines. The 412/21 DH lines were genotyped via genotyping by sequence (GBS). Analysis of the 412/21 population identified one quantitative trait loci (QTL) region associated with adult plant resistance to leaf rust on chromosome 1B. Phenotypic variation (%) explained by the putative leaf rust resistance QTL of 2013412 on 1B was as high as 40.1%. Kompetitive allele-specific (KASP) markers KASP_S1B_8414614 and KASP_S1B_8566239 were developed as markers for use in marker assisted selection. / Ph. D. / Disease resistance to leaf rust and stripe rust is important when growing soft red winter wheat. Genetic resistance can have a benefit to cost ratio of up to 27:1, considerably better than that of fungicide treatments. From 2013 to 2017 disease data was collected across multiple locations spanning the eastern United States (Arkansas, Georgia, Illinois, North Carolina, Texas, and Virginia). DNA molecular markers were used to identify specific chromosome regions containing genes associated with leaf and stripe rust resistance. DNA markers associated with genes conferring resistance to leaf rust resistance were identified in three chromosome regions, and genes in two regions were associated with stripe rust resistance. These genes and molecular markers associated with them can be used by scientists to further enhance resistance in wheat cultivars. Another study was conducted to determine if Lr18, a gene for leaf rust resistance that has a large effect, is present in the Virginia Tech soft red winter wheat breeding material. This gene (Lr18) is known to have been introduced from an ancestral species highly related to wheat. Wheat seedlings derived from crosses between lines postulated to carry Lr18 with susceptible lines were tested for resistance to a specific strain of leaf rust lacking virulence to Lr18. Genetic analysis of the ratio of resistant versus susceptible seedlings and association between DNA molecular markers and resistant seedlings were conducted to validate the presence of gene Lr18. A molecular marker linked tightly to gene Lr18 was identified in the study. This gene was found to be widely distributed in soft red winter wheat breeding materials and the molecular marker associated with gene Lr18 will be useful for scientists to further improve resistance in wheat cultivars.

Examination of variation at polymorphic microsatellite loci is a widely accepted method for determining parentage and examining genetic diversity within rainbow trout (Oncorhynchus mykiss) breeding programs. Genotyping costs are considerable; therefore, we developed a single-step method of co-amplifying twelve microsatellite loci in two hexaplex reactions. The protocol is explicitly described to ensure reproducible results. I applied the protocol to samples previously analyzed at the National Center for Cool and Coldwater Aquaculture (NCCCWA) with previously reported marker sets for a comparison of results. Each marker within the multiplex system was evaluated for duplication, null alleles, physical linkage, and probability of genotyping errors. Data from four of the 12 markers were excluded from parental analysis based on these criteria. Parental assignments were compared to those of a previous study that used five independently amplified microsatellites. Percentages of progeny assigned to parents were higher using the subset of eight markers from the multiplex system than with five markers used in the previous study (98% vs. 92%). Through multiplexing, use of additional markers improved parental allocation while also improving efficiency by reducing the number of PCR reactions and genotyping runs required. I evaluated the methods further through estimation of F-statistics, pairwise genetic distances, and cluster analysis among brood-years at the NCCCWA facility. These estimates were compared to those from nine independently amplified microsatellites used in a previous study. Fst metrics calculated between brood-years showed similar values of genetic differentiation using both marker sets. Estimates of individual pairwise genetic distances were used for constructing neighbor-joining trees. Both marker-sets yielded trees that showed similar subpopulation structuring and agreed with results from a model-based cluster analysis and available pedigree information. These approaches for detecting population substructure and admixture portions within individuals are particularly useful for new breeding programs where the founders' relatedness is unknown. The 2005 NCCCWA brood-year (75 full-sib families) was challenged with Flavobacterium psychrophilum, the causative agent of bacterial coldwater disease (BCWD). The overall mortality rate was 70%, with large variation among families. Resistance to the disease was assessed by monitoring post-challenge days-to-death. Phenotypic variation and additive genetic variation were estimated using mixed models of survival analysis. The microsatellite markers used were previously isolated from BAC clones that harbor genes of interest and mapped onto the rainbow trout genetic linkage map. A general relationship between UBA gene sequence types and MH-IA-linked microsatellite alleles indicated that microsatellites mapped near or within specific major histocompatibility (MH) loci reliably mark sequence variation at MH genes. The parents and grandparents of the 2005 brood-year families were genotyped with markers linked to the four MH genomic regions (MH-IA, MH-IB, TAP1, and MH-II) to assess linkage disequilibrium (LD) between those genomic regions and resistance to BCWD. Family analysis suggested that MH-IB and MH-II markers are linked to BCWD survivability. Tests for disease association at the population level substantiated the involvement of MH-IB with disease resistance. The impact of MH sequence variation on selective breeding for disease resistance is discussed in the context of aquaculture production. / Master of Science

A suspension system is to be made to increase driver comfort and ergonomics. This kind of system is widely used in a variety of vehicles, such as tractors and trucks, but is not yet standard for forklifts. The purpose of the case study is to design a fully mechanical, passive suspension system that can be retrofitted to a particular forklift without any cabin or chassis modification. The main focus will be on the linkages used to limit unwanted movement of the cabin. A concept utilizing 2 sets of parallel linkages is chosen to continue develop with the application of design for environment and design for manufacturing. This manages to reduce the total number of component sneeded for the system down to 33 from 43 in the first draft of the concept. The design needs to be dimensioned and further tested before a prototype is built. If the system then is implemented, it will have lasting effects on the forklift industry and the ergonomics of operators.

Das Jahr 2000 wird oft als Meilenstein der Entwicklung der Humangenetik bezeichnet. Eine Relevanz für die praktische Medizin erlangt das Humangenom-Projekt jedoch erst, wenn die Funktion der einzelnen Gene in komplexen physiologischen Systemen und die genetische Variabilität aufgeklärt sind. Die hier vorgelegten Studien beruhen auf der Annahme, dass der Einfluss genetischer Variabilität nicht nur im Vergleich kranker und gesunder Menschen sichtbar wird, sondern auch in der Variabilität physiologischer Parameter in der Allgemeinbevölkerung nachweisbar ist. Grundlage aller Studien war eine medizinische Untersuchung von gesunden eineiigen und zweieiigen Zwillingspaaren. Es wurde für Kennwerte des Herz-Kreislauf-Systems die Stärke genetischer Einflüsse (Heritabilität) bestimmt. Weiterhin erfolgten Kopplungs- und Assoziationsanalysen mit ausgewählten Kandidatengenen. Der Einfluss spezifischer Gene auf die Blutdruckregulation, die Herzgröße, EKG-Parameter sowie Blutfette konnte nachgewiesen werden. Weiterhin wurde der prinzipielle Nachweis erbracht, dass die funktionelle Untersuchung einzelner Gene in unausgelesenen Stichproben realisierbar ist. / The year 2000 is often called a milestone in the history of human genetics. The knowledge of the sequence of the human genome will only become relevant for clinical medicine when the function of genes within complex physiological systems as well as the genetic variability will be revealed. The studies reported here are based on the assumption that the influence of genetic variability does not only become obvious by comparison of affected and unaffected subjects but is as well detectable in the variability of physiological parameters in the general population. All studies are based on testing healthy mono- and dizygotic twins. We determined the heritability of various cardiovascular parameters. Furthermore selected candidate genes were tested by linkage and association analyses. We could demonstrate the influence of specific genes on blood pressure regulation, heart size, ECG and lipids. These studies are a proof of principle for the functional analysis of single genes in unselected random samples.