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Dobiáš, Roman. "Holografická injekce." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2021. http://www.nusl.cz/ntk/nusl-445541.
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Táto práca sa zaoberá návrhom a implementáciou nástroja, ktorý umožní používať klasické 3D OpenGL aplikácie na tzv. autostereoskopických displayoch s plným využitím ich hĺbkových možností a s minimálnym zásahom od užívateľa. Nástrojom je konverzná vrstva, ktorá umožní transparentne beh OpenGL aplikácií s interným rozšírením o vykreslenie z viacerých pohľadov vo formáte, vhodnom pre 3D display. Motiváciou tejto diplomovej práce je potenciálne rozšírenie tzv. autostereskopických displayov, ktoré je v súčasnosti závislé na cene a dostupnosti špecializovaných aplikácií pre tieto displaye. Text práce sa zaoberá dizajnom takejto vrstvy z pohľadu nutných API volaní, ktoré je potrebné korektne prepísať, aby aplikácie, vytvorené pomocou jednotlivých verzii štandardu OpenGL, pracovali správne, ako aj popisom problémov, ktoré vznikajú použitím rôznych vykreslovacích techník, a ktoré sú motiváciou pre komplexnejšie chovanie nástroja. Na záver práce sú ukážky konverzie programov, dopad na výkonnosť, ako aj identifikácia nedostatkov konverznej vrstvy s návrhmi možných riešení pre ďalší vývoj.
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Renström, Ida. "Evaluation of autostereoscopic 3Dvideo for short-term exposure : produced using semiautomatic stereo-to-multiview conversion." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-161885.
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Ida Renström Evaluation of autostereoscopic 3D video for short-term exposure, produced using semiautomatic stereo-to-multiview conversion ABSTRACT In this study, I investigate semiautomatic conversion from stereoscopic 3D to autostereoscopic 3D with multiple views. The conversion simplifies the production compared to creating autostereoscopic 3D from scratch. The research question of this study is; what level of holistic experience can be achieved from converted 3D compared to stereoscopic 3D video with glasses? The intended 3D contexts for this study require or are favored by glassesfree 3D with multiple views, and the exposure of 3D is shorttermed. I conducted user tests in a controlled setting as well as a public setting. The results show that it is difficult to make a general evaluation of the user experience of the final product, because different individuals perceive 3D very differently. Results from experiments in a controlled setting, where stereoscopic 3D was used as a direct reference, indicate that converted autostereoscopic 3D does not achieve the same perceived video quality as stereoscopic 3D. However, the fact that no glasses are needed compensates for this in the overall user experience. In an experiment with a public setting, where the participants' previous experiences of stereoscopic 3D were used as reference, a majority perceived the quality of converted autostereoscopic 3D to be better than, or equivalent to, that of previous experiences with stereoscopic 3D. A majority also said that the experience was positive. The latter experience made u se of an environment and situation that was close to real life and the intended types of contexts. Therefore, these results argue that autostereoscopic multiview 3D video converted from stereoscopic 3D is useful and gives a good holistic experience compared to stereoscopic 3D with glasses. This is in contexts favored by glassesfree 3D with multiple views and where the exposure of 3D is shorttermed. An autostereoscopic display in a retail space, where people walk by and view advertised material for a few seconds, is one example of a context suited for converted autostereoscopic 3D.Ida Renström Evaluering av autostereoskopisk 3D-video för korttidsexponering, producerad genom semiautomatisk stereo-till-multiview konvertering SAMMANFATTNING I denna studie undersöker jag semiautomatisk konvertering från stereoskopisk 3D till autostereoskopisk 3D med multipla vyer. Konverteringen förenklar produktionen, jämfört med att skapa autostereoskopisk 3D från grunden. Frågeställningen i denna studie är; vilken helhetsupplevelse resultatet av konverteringen ger i jämförelse med stereoskopisk 3D, inom vissa specifika användningsområden. Dessa användningsområden utgörs av 3D-sammanhang som starkt gynnas av glasögonfri 3D med multipla vyer och där exponeringen av 3D är kortvarig. Jag genomförde användartester i dels kontrollerad miljö samt offentlig miljö. Resultaten i denna studie visar att det är svårt att göra en generell utvärdering av användarupplevelsen av de resultat som denna konverteringsmetod ger, eftersom 3D upplevs väldigt olika av olika individer. Experimenten i kontrollerad miljö, där stereoskopisk 3D användes som direkt referens, visar att konverterad autostereoskopisk 3D håller en lägre upplevd kvalité än stereoskopisk 3D. Det faktum att inte glasögon behövs kompenserar dock för detta när man ser till den totala upplevelsen och de krav som situationen ställer. Vid det offentliga experimentet, med deltagarnas tidigare erfarenheter av stereoskopisk 3D som referens, ansåg en majoritet att den upplevda kvalitén av konverterad autostereoskopisk 3D var bättre än eller lika bra som tidigare erfarenheter av stereoskopisk 3D. Det senare experimentet genomfördes i en miljö och ett sammanhang som var mer likt verkligheten och det tänkta sammanhanget än det tidigare. Därför väger dessa resultat tungt och argumenterar för att autostereoskopisk 3D video med multipla vyer konverterad från stereoskopisk 3D är användbar och ger en bra helhetsupplevelse, inom användningsområden som starkt gynnas av glasögonfri 3D med multipla vyer och där exponeringen av 3D är kortvarig. Ett konkret exempel på detta kan vara att folk passerar en autostereskopisk skärm på en offentlig plats och möter reklam i 3D under några sekunder.
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Renström, Ida. "Evaluation of autostereoscopic 3D video for short-term exposure : produced using semiautomatic stereo-to-multiview conversion." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-159188.
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Wu, Dennis M. (Dennis Meng-Jiao). "Quantum-coupled single-electron thermal to electric conversion scheme." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42421.
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Includes bibliographical references (p. 236-242).Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2008.
A new thermal to electric conversion scheme based on an excitation transfer and tunneling mechanism is studied theoretically. Coulomb coupling dominates when the hot side and the cold side are very close. Two important concepts went into the device scheme: (1) Coulomb coupling, to try to increase throughput power (which is not subject to blackbody limit), and (2) a quantum dot implementation, to restrict number of states, to try to increase efficiency. Modeling efforts from Bloch equations, brute force numerical simulations, and the secular equations partitioning method are discussed. A hot-side quantum dot design of the device is considered. Alternative implementation where the hot-side is a plain sheet of metal or aluminum oxide is analyzed. We found that the model power/area is higher than the blackbody limit, and the predicted conversion efficiency is very high.
by Dennis M. Wu.
Ph.D.
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Al-Zubaidi, Saif Thamer Fadhil. "A novel power conversion approach for single phase systems." Thesis, University of Plymouth, 2015. http://hdl.handle.net/10026.1/3971.
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A novel single phase rectification technique with a new architecture and control scheme is proposed. The new rectifier consists of switched capacitor branch in parallel with the diode bridge rectifier. The switched capacitor branch includes a capacitor and a bidirectional switch arranged in series so the switch can control the charging and discharging of the capacitor. The control strategy is carefully designed to ensure the output voltage of the rectifier is above a chosen threshold level and to maintain high input power factor with reduced line current harmonics. Circuit configuration, design parameters, principles of operation and the mathematical analysis are presented. The new architecture provides a reduction in the size of the DC side capacitor. This reduction can be as low as less than 10% of the size of the typical smoothing capacitor in the conventional single phase rectifier. The proposed concept is verified by the experimental results over a range of case studies. A novel buck-boost DC-DC converter architecture is also proposed. This converter utilises the close inversely-coupled inductors topology in both its conversion stages (buck and boost). The new converter aims to reduce the switching noise that usually accompanies the buck and boost circuits. This can be done by maintaining a continuous flow of current in both converter stages which results in a large reduction in the back e.m.f induced in the main inductor and thus reduces the switching noise. The new converter architecture also provides a unique design of the passive clamped circuit. This circuit is used to recycle the leakage energies of the coupled inductors which results in an efficiency improvement of the converter and to limit the voltage stress on the power switches. Circuit con figuration, principles of operation and the transfer function are presented. The proposed concept is verified by the experimental and the simulated results of a range of case studies. The highest achieved efficiency observed in the experiments was 97:7%.
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Wang, Dan. "Design and integration of a single-chip low-power single-conversion CMOS cable TV tuner /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20WANG.
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Sharma, Preeti. "Coupled electrokinetic fluxes in a single nanochannel for energy conversion." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY100/document.
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Les phénomènes électrocinétiques couplés au sein d'un nanocanal sont d'intérêt pour la conversion d'énergie et la production d'électricité reposant sur le mélange contrôlé d'eau douce et d'eau salée aussi appelée "énergie bleue". L'origine des phénomènes est lié à l'interaction avec des parois chargées et au transport d'ions au sein de ce qu'on nomme les couches de Debye. Ce travail vise à une meilleure compréhension de la physique et des phénomènes de transport dans ces couches dans le cadre de solutions confinées dans des nanocanaux.Une instrumentation spécifique a été développée pendant la thèse pour étudier les mécanismes qui gouvernent ces flux couplés. L'idée est de caractériser simultanément le transport de masse et le courant électrique au sein d'un nanocanal soumis à une différence de salinité de pression ou de tension électrique. Ce travail est divisé en trois parties.Dans la première partie, est décrite une cellule conçue pour la mesure et le contrôle de courant et tension électrique en présence de différence de pression ou de salinité au bornes d'un nanopores. L'utilisation de la cellule est illustrer dans le cas d'une membrane nanoporeuse de nafion.La seconde partie est focalisée sur une méthode simple de préparation d'un nanocanal directement connectable à un dispositif macroscopique. Le nanocanal, d'un micromètre de long, présente une géométrie conique, d'angle ajustable, et des extrémités équipées d'électrode déposées par pulvérisation cathodique.La troisième partie, concerne le développement d'une méthode pour la mesure directe de débit jusqu'à 10 pL/min s'écoulant au sein d'un nanocanal. Cette méthode combinée à une caractérisation électrique, pourra être utilisée, en présence de gradient de pression, de tension ou de salinité pour mesurer le débit et le courant électrique au sein d'un nanocanal de manière simultanée et indépendanteCoupled electrokinetic phenomena within nanochannel are of interest for energy harvestingand production of electricity based on the controlled mixing of river water with sea water known as "blue energy". The origin of the phenomena is related to interaction with charged walls and transport of ions within the so called Debye layer. This work aims at a better understanding of the physics and transport phenomena in this layer associated with solution confined in nanochannel.A specific instrumentation has been developed during this thesis to study the mechanisms governing coupled nanofluics fluxes. The idea is to characterize simultaneously the mass transport within the nanochannel and the electrical current driven through the nanochannel by the application of either salinity difference , pressure difference or voltage difference across the channel. The thesis is divided into three parts.In the first part, a custom made flow cell and experimental conditions to control and measure various fluxes is presented. The capability of cell to measure current or voltage under applied pressure or salinity gradient is presented taking the benefit of commercial nanoporous Nafion membrane.The second part is focused on an easy way of preparation of nanochannel sample in the form of single chip, in which nanochannel is interfaced to micro and macroscopic world. A well-controlled, 1.4µm long nanochannel of conical geometry with a maximum aspect ratio of 10 is fabricated. The minimum apex size of nanochannel achieved here is 50 nm which is about 30 times less than the length of channel. The presence of electrode directly at the interface of nano to micro cavity allow to perform electrical characterization of nanochannel with high precision.The third part of the thesis is devoted to the development of a method for the direct measurement of flow rate as low as 10 pL/min across a single nanochannel. This measurement approach combined with electrical measurement, could be used, in presence of pressure, voltage or salinity gradient, to measure the flow rate and the electrical current across a single nanochannel simultaneously and independently
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Dhital, Bharat. "Single-molecule interfacial electron transfer dynamics in solar energy conversion." Bowling Green State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1477997482545831.
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Leung, Wing C. "Effects of single nucleotide polymorphisms in BCMO1 on β-carotene conversion." Thesis, University of Newcastle Upon Tyne, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443996.
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Baltierrez, Jason. "Multiple Input, Single Output DC-DC Conversion Stage for DC House." DigitalCommons@CalPoly, 2019. https://digitalcommons.calpoly.edu/theses/2028.
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n this thesis project, a proposed architecture for the multiple input, single output conversion stage for the DC House was designed, simulated, and tested. This architecture allows for multiple different input sources to be used to create a single higher power output source. The design uses a DC-DC boost converter with a parallelable output which has been demonstrated to allow increased total output power as a function of the number of input sources available. The parallelable output has been shown to distribute load amongst the input sources relatively closely to optimize the system. This approach is also desirable since it allows for flexibility in multiple configurations it can be used in. The design was tested using hardware and data results show the performance met and exceeded the needs of the DC House project. Data was taken for configuration with 1, 2, 3, and 4 input sources providing greater than 600W of total output power at an efficiency of greater than 92%. This architecture demonstrates the possibility of expanding the total available power for a single output in proportion to the number of available input sources.
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Sevinç, Papatya C. "Single-Molecule Interfacial Electron Transfer in Solar Energy Conversion and Bioremediation." Bowling Green State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1367339768.
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Reddy, Serendra. "Automatic 2D-to-3D conversion of single low depth-of-field images." Doctoral thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/24475.
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This research presents a novel approach to the automatic rendering of 3D stereoscopic disparity image pairs from single 2D low depth-of-field (LDOF) images. Initially a depth map is produced through the assignment of depth to every delineated object and region in the image. Subsequently the left and right disparity images are produced through depth imagebased rendering (DIBR). The objects and regions in the image are initially assigned to one of six proposed groups or labels. Labelling is performed in two stages. The first involves the delineation of the dominant object-of-interest (OOI). The second involves the global object and region grouping of the non-OOI regions. The matting of the OOI is also performed in two stages. Initially the in focus foreground or region-of-interest (ROI) is separated from the out of focus background. This is achieved through the correlation of edge, gradient and higher-order statistics (HOS) saliencies. Refinement of the ROI is performed using k-means segmentation and CIEDE2000 colour-difference matching. Subsequently the OOI is extracted from within the ROI through analysis of the dominant gradients and edge saliencies together with k-means segmentation. Depth is assigned to each of the six labels by correlating Gestalt-based principles with vanishing point estimation, gradient plane approximation and depth from defocus (DfD). To minimise some of the dis-occlusions that are generated through the 3D warping sub-process within the DIBR process the depth map is pre-smoothed using an asymmetric bilateral filter. Hole-filling of the remaining dis-occlusions is performed through nearest-neighbour horizontal interpolation, which incorporates depth as well as direction of warp. To minimising the effects of the lateral striations, specific directional Gaussian and circular averaging smoothing is applied independently to each view, with additional average filtering applied to the border transitions. Each stage of the proposed model is benchmarked against data from several significant publications. Novel contributions are made in the sub-speciality fields of ROI estimation, OOI matting, LDOF image classification, Gestalt-based region categorisation, vanishing point detection, relative depth assignment and hole-filling or inpainting. An important contribution is made towards the overall knowledge base of automatic 2D-to-3D conversion techniques, through the collation of existing information, expansion of existing methods and development of newer concepts.
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Marinus, Stuart. "Using passive elements and control to implement single- to three-phase conversion." Master's thesis, University of Cape Town, 1999. http://hdl.handle.net/11427/22647.
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Scholz, Matthias. "New light sources for quantum information processing single photons from single quantum dots and cavity enhanced parametric down conversion." Berlin Logos-Verl, 2009. http://d-nb.info/99472098X/04.
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El, Debs Bachir. "Functional single-cell hybridoma screening using droplet-based microfluidics." Strasbourg, 2011. http://www.theses.fr/2011STRA6182.
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µm de diamètre) pour la culture de cellules mammifères. On a utilisé ce système pour sélectionner spécifiquement des cellules hybridomes sécrétant des anticorps inhibant l’Enzyme de Conversion de l’Angiotensine. -1 (ECA-1). L’émulsion contenant les cellules encapsulées dans les gouttes a été incubé pendant 6 heurres pour obtenir une quantité considérable d’anticorps avec l’ECA-1. Ensuite, cette émulsion a été réinjectée dans une puce microfluidique, fusionnée avec des gouttes contenant un mélange réactionnel permettant l’obtention d’un signal fluorescent d° à l’activité de l’ECA-1. Les gouttes ayant une faible intensité de fluorescence ont été triées. Une variance considérable dans le taux d’expression d’anticorps a été constatée au niveau mono-cellulaire au sein d’une même lignée de cellules hybridomes o_ les cellules exprimant un taux élevé d’anticorps ont été isolées et cultivées. Ce système permet le criblage de 5_104 cellules par heure et pourra être utiliser pour le criblage de lymphocytes B non immortaliséesThis thesis describes a microfluidic platform allowing the functional screening of hybridoma cells on the single-cell level. In this system, individual cells from a heterogeneous population are encapsulated into aqueous microdroplets of a water-in-oil emulsion and assayed directly for the release of antibodies inhibiting drug targets. The microfluidic setup comprises a novel fully integrated chip which allows reinjection, fusion and sorting of droplets sufficiently large (~100 µm in diameter) for the cultivation of mammalian cells. We successfully used this device for the specific selection of hybridoma cells releasing antibodies inhibiting angiotensin converting enzyme-1 (ACE-1). After cell encapsulation, the resulting emulsion was incubated off-chip for 6h to obtain significant antibody concentrations. Subsequently, the droplets were reinjected into another chip, fused with a second droplet species containing all components of a fluorescence assay for ACE-1 activity, and droplets with low fluorescence intensity (indicating ACE-1 inhibition) were sorted. A wide variance in antibody expression levels at the single-cell level within a single hybridoma line was observed and high expressors could be sorted and recultivated. The approach enabled screening more than 5_104 cells per hour and should even be applicable to non-immortalized primary B-cells, as no cell proliferation is required
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Leisten, Joseph Michael. "Application of a new high speed gate turn off thyristor in single ended resonant converter topologies." Thesis, University of Brighton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239723.
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Martynov, Konstantin M. Eng Massachusetts Institute of Technology. "Investigation of multiple-input single-output power conversion for advanced solar cell systems." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113175.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017Cataloged from PDF version of thesis.
Includes bibliographical references (pages 217-219).
Laterally-Arrayed Multiple-Bandgap (LAMB) solar cells provide the potential for improved energy capture, but require sophisticated interconnection and power conversion. Different topologies for a cell block interconnection were investigated and equations providing the estimated losses in those topologies were derived. The interconnected cell block is used as an input to the Multiple-Input Single-Output (MISO) power converter. Different power converter topologies and control schemes are considered, among which MISO buck converter with Pulse-Width Modulated (PWM) control is selected. For the maximum power extraction, a "Perturb and Observe" (P&O) algorithm is modified to fit the MISO buck converter topology and to account for special operation cases that could arise due to the multiple-input nature of the power converter. To verify the theoretical assumptions, a discrete-component prototype has been built and various experiments performed with it.
by Konstantin Martynov.
M. Eng.
M.Eng. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science
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Kendall, Timothy Martin James. "Power scaling and nonlinear frequency conversion of single-frequency lasers based on Nd:YLF." Thesis, University of Southampton, 2004. https://eprints.soton.ac.uk/42433/.
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This thesis presents a strategy for power-scaling diode-end-pumped solid-state lasers based on Nd:YLF operating on the 1.053μm line whilst retaining, efficient, single-frequency, diffraction limited output, the characteristics of low power operation. This strategy reduces the effects of energy transfer up-conversion (ETU), which can decrease the lifetime of the upper lasing level and increase the heat generated per unit volume within the laser rod, increasing the effects of detrimental thermally related problems such as thermal lensing, stress-induced birefringence and stress induced laser rod fracture. Also a passive technique for mode-hopping-suppression is described, allowing the oscillating frequency within the laser cavity to tune over many axial mode spacings before a mode-hop occurs. In order to de-couple the problems of laser resonator power scaling from the maintenance of robust and reliable single-frequency operation, the Nd:YLF laser oscillator output is amplified via Nd:YLF based amplifier stages. A model is presented of the effects of ETU on thermal lensing and small signal gain within the amplifiers along with projected results for further power-scaling prospects. In order to increase the frequency tuning capabilities of the master-oscillator-power-amplifier (MOPA), it was used to pump a series of cw singly-resonant optical parametric oscillators (SROs) based on periodically-poled lithium niobate. Although SROs are inherently single-frequency they suffer detrimentally from mode-hopping, therefore in the final stages of this thesis, we propose to utilise the novel passive technique for mode-hopping-suppression with the SRO cavities in order to achieve robust and reliable single-frequency output. Theoretical expressions and design strategy for low SRO threshold and efficient slope efficiency are expressed along with detailed analysis of the mode-hopping nature of their output. Preliminary results for cw SROs are presented and details of SRO mode-hopping-suppression are included
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JARYNOWSKI, ROBERT J. "GREATER THAN 3 MHZ MULTICHANNEL A/D CONVERSION ON A SINGLE VME BOARD." International Foundation for Telemetering, 1991. http://hdl.handle.net/10150/612906.
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International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, NevadaA VME computer can be used to provide the basis for a telemetry data processing station. Using “off-the-shelf cards” the designer is able to build up a front end that meet several of the data processing requirements. The ease in interfacing to the VME bus also provides a convenient platform for the development of highly specialized interfaces requiring programmable control. The results are a low-cost highperformance system that is easily expandable as needs and/or technology grow. Based on this strategy, the Physical Science Laboratory (PSL) at New Mexico State University developed a multichannel high-speed analog-to-digital converter (ADC) assembly on a single VME board. The design approach used at PSL to develop the VME-based ADC is discussed in an effort to describe both developments in analog-to-digital conversion integrated circuits and the use of a VME CPU to control them for data processing purposes.
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Dhar, Romit. "Growth and optimization of piezoelectric single crystal transducers for energy harvesting from acoustic sources." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Dissertations/Spring2009/R_Dhar_031309.pdf.
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Wang, Kunrong. "High-Frequency Quasi-Single-Stage (QSS) Isolated AC-DC and DC-AC Power Conversion." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/29394.
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The generic concept of quasi-single-stage (QSS) power conversion topology for ac-dc rectification and dc-ac inversion is proposed. The topology is reached by direct cascading and synchronized switching of two variety of buck or two variety of boost switching networks. The family of QSS power converters feature single-stage power processing without a dc-link low-pass filter, a unidirectional pulsating dc-link voltage, soft-switching capability with minimal extra commutation circuitry, simple PWM control, and high efficiency and reliability.
A new soft-switched single-phase QSS bi-directional inverter/rectifier (charger) topology is derived based on the QSS power conversion concept. A simple active voltage clamp branch is used to clamp the otherwise high transient voltage on the current-fed ac side, and at the same time, to achieve zero-voltage-switching (ZVS) for the switches in the output side bridge. Seamless four-quadrant operation in the inverter mode, and rectifier operation with unity power factor in the charger (rectifier) mode are realized with the proposed uni-polar center-aligned PWM scheme. Single-stage power conversion, standard half-bridge connection of devices, soft-switching for all the power devices, low conduction loss, simple center-aligned PWM control, and high reliability and efficiency are among its salient features. Experimental results on a 3 kVA bi-directional inverter/rectifier prototype validate the reliable operation of the circuit. Other single-phase and three-phase QSS bi-directional inverters/rectifiers can be easily derived as topological extensions of the basic QSS bi-directional inverter/rectifier.
A new QSS isolated three-phase zero-voltage/zero-current-switching (ZVZCS) buck PWM rectifier for high-power off-line applications is also proposed. It consists of a three-phase buck bridge switching under zero current and a phase-shift-controlled full-bridge with ZVZCS, while no intermediate dc-link is involved. Input power and displacement factor control, input current shaping, tight output voltage regulation, high-frequency transformer isolation, and soft-switching for all the power devices are realized in a unified single stage. Because of ZVZCS and single-stage power conversion, it can operate at high switching frequency while maintaining reliable operation and achieving higher efficiency than standard two-stage approaches. A family of isolated ZVZCS buck rectifiers are obtained by incorporating various ZVZCS schemes for full-bridge dc-dc converters into the basic QSS isolated buck rectifier topology. Experimental and simulation results substantiate the reliable operation and high efficiency of selected topologies.
The concept of charge control (or instantaneous average current control) of three-phase buck PWM rectifiers is introduced. It controls precisely the average input phase currents to track the input phase voltages by sensing and integrating only the dc rail current, realizes six-step PWM, and features simple implementation, fast dynamic response, excellent noise immunity, and is easy to realize with analog circuitry or to integrate. One particular merit of the scheme is its capability to correct any duty-cycle distortion incurred on only one of the two active duty-cycles which often happens in the soft-switched buck rectifiers, another merit is the smooth transition of the input currents between the 60o sectors. Simulation and preliminary experimental results show that smooth operations and high quality sinusoidal input currents in the full line cycle are achieved with the control scheme.Ph. D.
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Liao, Miao. "Single View Modeling and View Synthesis." UKnowledge, 2011. http://uknowledge.uky.edu/gradschool_diss/828.
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This thesis develops new algorithms to produce 3D content from a single camera. Today, amateurs can use hand-held camcorders to capture and display the 3D world in 2D, using mature technologies. However, there is always a strong desire to record and re-explore the 3D world in 3D. To achieve this goal, current approaches usually make use of a camera array, which suffers from tedious setup and calibration processes, as well as lack of portability, limiting its application to lab experiments.
In this thesis, I try to produce the 3D contents using a single camera, making it as simple as shooting pictures. It requires a new front end capturing device rather than a regular camcorder, as well as more sophisticated algorithms. First, in order to capture the highly detailed object surfaces, I designed and developed a depth camera based on a novel technique called light fall-off stereo (LFS). The LFS depth camera outputs color+depth image sequences and achieves 30 fps, which is necessary for capturing dynamic scenes. Based on the output color+depth images, I developed a new approach that builds 3D models of dynamic and deformable objects. While the camera can only capture part of a whole object at any instance, partial surfaces are assembled together to form a complete 3D model by a novel warping algorithm.
Inspired by the success of single view 3D modeling, I extended my exploration into 2D-3D video conversion that does not utilize a depth camera. I developed a semi-automatic system that converts monocular videos into stereoscopic videos, via view synthesis. It combines motion analysis with user interaction, aiming to transfer as much depth inferring work from the user to the computer. I developed two new methods that analyze the optical flow in order to provide additional qualitative depth constraints. The automatically extracted depth information is presented in the user interface to assist with user labeling work.
In this thesis, I developed new algorithms to produce 3D contents from a single camera. Depending on the input data, my algorithm can build high fidelity 3D models for dynamic and deformable objects if depth maps are provided. Otherwise, it can turn the video clips into stereoscopic video.
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Al, Wahabi Saeed M. H. "Conversion of methanol to light olefins on SAPO-34: kinetic modeling and reactor design." Texas A&M University, 2003. http://hdl.handle.net/1969.1/1579.
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In this work, the reaction scheme of the MTO process was written in terms of elementary steps and generated by means of a computer algorithm characterizing the various species by vectors and Boolean relation matrices. The number of rate parameters is very large. To reduce this number the rate parameters related to the steps on the acid sites of the catalyst were modeled in terms of transition state theory and statistical thermodynamics. Use was made of the single event concept to account for the effect of structure of reactant and activated complex on the frequency factor of the rate coefficient of an elementary step. The Evans-Polanyi relation was also utilized to account for the effect of the structure on the change in enthalpy. The structure was determined by means of quantum chemical software.
The number of rate parameters of the complete reaction scheme to be determined from experimental data is thus reduced from 726 to 30. Their values were obtained from the experimental data of Abraha by means of a genetic algorithm involving the Levenberg-Marquardt algorithm and combined with sequential quadratic programming.
The retained model yields an excellent fit of the experimental data. All the parameters satisfy the statistical tests as well as the rules of carbenium ion chemistry. The kinetic model also reproduces the experimental data of Marchi and Froment, also obtained on SAPO-34. Another set of their data was used to introduce the deactivation of the catalyst into the kinetic equations.
This detailed kinetic model was used to investigate the influence of the operating conditions on the product distribution in a multi-bed adiabatic reactor with plug flow. It was further inserted into riser and fluidized bed reactor models to study the conceptual design of an MTO reactor, accounting for the strong exothermicity of the process. Multi-bed adiabatic and fluidized bed technologies show good potential for the industrial process for the conversion of methanol into olefins.
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Nguyen, Francois. "Cooper pair box circuits : two‐qubit gate, single‐shot readout, and current to frequency conversion." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2008. http://tel.archives-ouvertes.fr/tel-00390074.
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During this thesis, we have used superconducting circuits with Josephson junctions, derived from the Cooper pair box, in order to implement quantum bits (qubits). To implement two-qubit gates, we have developed a new circuit, the quantroswap, which consists in two capacitively coupled Cooper pair box, each of them being manipulated and read separately. We have demonstrated coherent exchange of energy between them, but we have also observed a problem of qubit instability.
In order to avoid this spurious effect, we have implemented another circuit based on a charge insensitive split Cooper pair box coupled to a non-linear resonator for readout-out purpose. We have measured large coherence time, and obtained large readout fidelity (90%) using the bifurcation phenomenon.
For metrological purpose, microwave reflectometry measurement on a quantronium also allowed us to relate an applied current I to the frequency f=I/2e of induced Bloch oscillations.
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Nguyen, François. "Cooper pair box circuits : two-qubit gate, single-shot readout, and current to frequency conversion." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2008. http://tel.archives-ouvertes.fr/tel-00812431.
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Cette thèse porte sur le développement de circuits supraconducteurs à jonctions Josephson, issus de la boîte à paire de Cooper, pour réaliser des bits quantiques (qubits). La version quantronium de ce circuit avait déjà démontré une cohérence quantique assez bonne pour faire des portes logiques à un qubit. Pour réaliser des portes logiques à deux qubits, nous avons développé un circuit, le quantroswap, fait de deux quantroniums couplés, chaque qubit pouvant être piloté et mesuré séparément. Nous avons démontré l'échange cohérent d'état entre les deux qubits, mais aussi observé un effet rédhibitoire d'instabilité dans ces qubits. Pour l'éviter, nous avons réalisé un nouveau circuit fait d'une boite à paires de Cooper insensible au bruit en charge électrique et stable, couplée à un résonateur non linéaire pour sa lecture. Nous avons obtenu un temps de cohérence long (~1 μs), et une très bonne fidélité de lecture (90%) du qubit en utilisant le phénomène de bifurcation. Dans un but métrologique, la mesure par réflectométrie microonde du quantronium a aussi permis de relier un courant I injecté dans le circuit à la fréquence f=I/2e des oscillations de Bloch induites.
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Corsaro, Agnieszka. "Optimization of a Single Reactor Process for the Selective Conversion of Coal to Liquid Fuels." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/dissertations/429.
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The conversion of synthesis gas to desirable liquid fuels in gasoline and diesel range in a single reactor process with simultaneous use of FT and cracking catalysts was investigated in this dissertation. Co-based catalyst and ZSM-5 were used as a FT and cracking catalysts, respectively. The structural and textural properties of ZSM-5 were analyzed by XRD, BET and particle size analysis. Following, commercially available FT and cracking catalyst were tested in the newly designed fixed bed dual-zone reactor under 350 psi; syngas with H2/CO ratio in the amount of 2, and flow rate of 70, 100 and 130 smL/min; and 0.5, 1.25 and 2.5 g of ZSM-5. The temperature for the FT Co-based catalyst was maintained constant at 190 °C, whereas, the temperature for the additionally implemented cracking catalyst was varied (250, 300 and 350 °C). The effect of operating reaction conditions such as syngas flow rate, Si/Al molar ratio; temperature and loading of cracking catalyst were investigated. It was shown, that in general, decrease of syngas flow rate, ipso facto increase in residence time, resulted in decrease of gasoline and diesel fuel production, whereas reduction of ZSM-5 loading improved the formation of C5 - C17 paraffins. An enhancement in gasoline and diesel paraffin range formation was also observed with the decrease of cracking temperature. In addition, the effect of variation in operating conditions was evaluated for liquid paraffin production and dominance of chain propagation reactions over cracking and/or isomerizarion reactions with cracking catalyst loading and syngas flow rate was observed. As a consequence, the results employing ZSM-5 showed increased formation of light hydrocarbons and aromatics; and reduction of heavier paraffins production. Finally, the effect of various Si/Al molar ratios in the amount of 50, 80 and 280 were studied in this research. It was found, that the decrease in acidity of ZSM-5 zeolite enhanced the selectivity towards desirable products as well as heavier paraffins, but suppressed the formation of CH4. Furthermore, the isomerization reactions became favored in expense of cracking reactions.
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Niemi, David A. "Coupling Down Converted Light Into Single Mode Fibers." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/893.
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We investigate the influence of the pump and collection mode parameters on the collection efficiency of Type I down converted photons into single mode fibers. For best single and coincidence counting rates, we find that the mode sizes should be close to the same size and that the mode waists should be located near the down-conversion crystal. Larger collection waists give higher collection efficiencies, but lower singles counts.
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Zaske, Sebastian [Verfasser], and Christoph [Akademischer Betreuer] Becher. "Quantum frequency down-conversion of single photons in nonlinear optical waveguides / Sebastian Zaske. Betreuer: Christoph Becher." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2013. http://d-nb.info/1052904742/34.
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Şcheul, Ancuţa Teodora. "Two approaches for a simpler STED microscope using a dual-color laser or a single wavelength." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENY040/document.
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La microscopie STED (stimulated emission depletion ou déplétion par émission stimulée) est une des méthodes les plus répandues de microscopie de super-résolution. Dans un microscope STED, un faisceau en anneau se superpose avec le faisceau d'excitation et éteint les fluorophores en périphérie du faisceau d'excitation par émission stimulée. Au centre de l'anneau, où le faisceau STED a une intensité nulle, la fluorescence reste intacte. Cette technique nécessite un montage complexe dans lequel deux faisceaux laser, en général issus de deux sources différentes, doivent être parfaitement alignés et superposés. Dans ce travail de thèse, nous proposons deux configurations STED qui ont pour but de simplifier le montage et de réduire le coût total d'un tel système. L'idée de base dans les deux cas est d'utiliser la même source laser à la fois pour l'excitation et la déplétion par émission stimulée. Dans la première configuration, nous avons développé une source bicolore originale basée sur un laser Nd-YAG microchip. Ce laser microchip délivre simultanément des impulsions sub- ns à deux longueurs d'onde, 355 nm (excitation) et 532 nm (déplétion), qui sont générés par conversion harmonique à partir d'une émission laser Nd-YAG et offrent l'avantage d'être intrinsèquement alignées et synchronisées. Afin de trouver des colorants appropriés pour cette source particulière, nous avons développé une méthode de caractérisation et testé différents colorants Nous avons construit un microscope à partir de cette source laser et obtenu des images avec une résolution améliorée. La réduction du volume d'excitation a été confirmée par spectroscopie de corrélation de fluorescence (FCS). Cependant, les aberrations chromatiques des optiques utilisées limitent les performances du montage actuel. Une perspective prometteuse serait de combiner le STED à la microscopie à feuille de lumière (SPIM), plus tolérante des défauts d'achromatisme, et nous montrons les premiers résultats de cette approche. Dans la seconde configuration, les aberrations chromatiques ne sont plus un problème puisqu' une seule longueur d'onde est utilisée pour l'excitation (par absorption à deux photons) et la déplétion. En jouant sur la durée de l'impulsion (et donc la valeur de l'intensité crête), un de ces deux procédés peut être favorisé. La fluorescence est excitée à deux photons par une impulsion femtoseconde, puis est éteinte par émission stimulée à un photon avec une impulsion étirée. Nous avons utilisé une technique résolue en temps (Time-Correlated Single Photon Counting - TCSPC) pour étudier l'efficacité de déplétion du colorant DCM en solution. Les simulations numériques montrent que cette méthode peut être appliquée à la microscopie de super résolution. En fin de cette partie, nous présentons les premières images obtenues avec un microscope développé au laboratoire qui permet l'excitation à deux photons et la déplétion à un photon avec une seule longueur d'onde, ainsi que l' amélioration de la résolution observée. Dans ce travail, nous avons donc mis en place expérimentalement, pour la première fois, deux concepts destinés à simplifier en utilisant deux sources laser originalesStimulated emission depletion (STED) is a well-known super-resolution method. In a STED microscope, a doughnut-shaped beam is superimposed with the excitation beam and keeps the fluorophores in the periphery of the excitation spot in a dark state by stimulated emission, thus effectively improving the spatial resolution in a scanning configuration. This technique requires a complex setup since two laser beams, generally from different sources need to be perfectly aligned. In this work we propose two STED configurations that will simplify the setup and reduce the total cost of such a system. The basic idea in both cases is to use the same laser source for both excitation and stimulated emission depletion. In the first setup we have developed an original two-color source based on a microchip Nd-YAG laser. This microchip laser simultaneously delivers sub-ns pulses at two wavelengths, 355 nm (excitation) and 532 nm (depletion), which are generated by harmonic conversion from an Nd-YAG laser emission and offer the advantage of being intrinsically aligned and synchronized. Further work consisted in determining suitable dyes for this particular source. We have built a microscope setup based on this laser source and obtained images with an improved resolution. The confirmation of the reduction of the excitation volume is showed by Fluorescence Correlation Spectroscopy (FCS) measurements. However, the performance of this system is limited by chromatic aberrations. The combination of Selective Plane Illumination Microscopy (SPIM) with STED is considered. In the second setup the chromatic aberrations are no longer a problem since the same wavelength is used for two photon excitation and one photon depletion. By playing on the duration of the pulse (thus the instantaneous intensity), one of these two processes can be favored. Fluorescence was excited by two photon absorption with a femtosecond pulse, then depleted by one photon stimulated emission with a stretched pulse. We used the Time Correlated Single Photon Counting (TCSPC) method to study the depletion efficiency of DCM dye in solution and numerical simulations show that this method can be applied to super-resolved microscopy. In the end we present the preliminary images obtained with a home-built Two-photon Single wavelength STED microscope and the resolution improvement obtained. Further improvements are to be made to the custom microscope. In this work we have experimentally implemented, for the first time, two concepts meant to simplify the STED setups by using original sources
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Zhang, Yusheng. "Development of a bench scale single batch biomass to liquid fuel facility." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/811.
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The research described in this dissertation was motivated by the global demand for energy that is not dependent on coal, oil, natural gas and other non-renewable fossil fuels. The technology used in this project is related to the use of biomass to produce a viable alternative to conventional sources of fuel. A bench scale biomass to liquid (BTL) facility was built and tested. This produced results confirming the feasibility of the BTL process. The findings of the pilot study outlined in this dissertation justified the conclusion that the next step will be to expand the capacity and productivity of the BTL pilot plant to an industrial scale. Biomass comes from a variety of renewable sources that are readily available. In this case, the material used in the fixed bed biomass gasification facility to generate wood gas was agricultural and forestry waste, such as straw and wood chips. The gasifier had the capacity to produce up to 10 cubic metres/hr of gas with a carbon monoxide and hydrogen content of between 20–40% by volume, when it was operated at ambient pressure and with air as the oxidizer. The gas, produced at a temperature above 700º C, was cooled in a quench/water scrubber in order to remove most of the mechanical impurities (tars and water-soluble inorganic particles), condensed and dried with corn cobs before being compressed in cylinders at over 100 bar (g) for use in the Fischer-Tropsch Synthesis (FTS). The syngas was subjected further to a series of refining processes which included removal of sulphur and oxygen. The sulphur removal technology chosen entailed applying modified activated carbon to adsorb H2S with the help of hydrolysis in order to convert organic sulphur impurities into H2S which reduced the sulphur content of the gas to less than 5 ppbv. Supported cobalt catalyst (100 grams), were loaded into a single-tube fixed bed FT reactor with an inner diameter of 50 mm. The reactor was fitted with a heating jacket through which, heated oil ran to cool the reactor during a normal reaction occurring at < 250 ºC, while nitrogen was used in the heating jacket during reduction, which occurred at temperatures up ~ 350 ºC. The FTS reaction was carried out at different pressures and temperatures. Liquid and wax products were produced from the facility. The properties of the liquid and solid hydrocarbons produced were found to be the same as FT products from other feed stocks, such as natural gas and coal.
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Brito, Rozas José M. [Verfasser], and Jürgen [Akademischer Betreuer] Eschner. "Quantum interfaces based on single photons from parametric down-conversion / José M. Brito Rozas. Betreuer: Jürgen Eschner." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2016. http://d-nb.info/1097263290/34.
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Strahan, Richard Johnston. "Energy conversion by permanent magnet machines and novel development of the single phase synchronous permanent magnet motor." Thesis, University of Canterbury. Electrical and Electronic Engineering, 1998. http://hdl.handle.net/10092/5602.
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Energy methods are widely used and well understood for determining the torque or force in machines which do not contain permanent magnets. Energy methods are employed to calculate torques or forces of magnetic origin after determination of the energy stored in the electromechanical coupling field. In this thesis, the energy stored in a permanent magnet system is defined, and the energy-coenergy relationship is determined. It is shown how residual magnetism can be incorporated into classical electromechanical coupling theory. It is therefore shown how equations for torques or forces can be derived for permanent magnet systems using energy methods.
An analytical method of calculating permanent magnet reluctance torque is developed. The method uses an elementary expression for the magnetic field to obtain the stored energy. This enables an analytical expression for the reluctance torque waveform to be obtained. The method is demonstrated to provide a powerful and fast design tool. The method can be generally applied to reluctance torque problems where the airgap is reasonably smooth.
The single phase synchronous permanent magnet motor is used in domestic appliances. It is a motor of very simple construction and high reliability, which is directly connected to an AC mains supply, and runs at synchronous speed. It is becoming increasingly used in preference to the shaded pole induction motor. However, its application is limited by the following characteristics. There is no control over the final direction of rotation, unless a mechanical blocking device is used. There are rotor positions at which only a very small starting torque is available. The characteristic twice electrical frequency torque pulsation yields a speed modulation of the same frequency, which can cause acoustic noise problems. A method of improving torque quality by improving the motor design is proposed to alleviate these limiting characteristics. This is achieved by designing a permanent magnet reluctance torque which cancels out the effect of the backward rotating component of the stator field. In this novel design, the permanent magnet reluctance torque effectively acts as a second balancing phase.
An unconventional technique for starting a single phase synchronous permanent magnet motor is demonstrated. This technique uses an inductive reluctance torque, provided by placing a suitably shaped iron lamination on the rotor, to rotate the rotor to a position from which starting can occur.
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TEMPORAO, GUILHERME PENELLO. "SINGLE PHOTON COUNTING IN THE NEAR- AND MID-INFRARED VIA FREQUENCY UP-CONVERSION APPLIED TO QUANTUM COMMUNICATIONS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=10510@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIORDois dispositivos de contagem de fótons únicos, sensíveis a comprimentos de onda no infravermelho próximo e médio, são propostos e experimentalmente investigados. Ambos utilizam uma técnica de dois estágios, composta de uma etapa inicial de conversão de freqüências em um cristal não-linear seguida de detecção por um fotodiodo avalanche de silício. Enquanto o primeiro projeto é voltado à detecção de fótons únicos a 1.55 μm para comunicações quânticas via fibra óptica, usando um processo intra-cavidade, o segundo projeto prevê o desenvolvimento de um contador de fótons operando a 4.65 μm para sistemas de espaço livre. Neste caso, um estudo de viabilidade para um sistema prático de criptografia quântica operando em um comprimento de onda no infravermelho médio é realizado. Os resultados mostram que, usando a tecnologia disponível na atualidade, tal sistema pode ser construído, embora sua utilidade se mostre restrita a enlaces possuindo certas condições meteorológicas específicas.
Two single photon counting devices, operating at near- and mid-infrared wavelengths, are introduced and experimentally investigated. Both use a twostage technique, comprised of an initial frequency up-conversion procedure inside a nonlinear crystal followed by a silicon avalanche photodiode. Whereas the first project consists on detection of single photons at 1.55 ìm for fiber-optic-based quantum communications, using a cavity-enhanced procedure, the second project envisions the development of a single-photon counter operating at 4.65 ìm for free-space systems. In this case, a feasibility study for a practical quantum key distribution system operating in a mid-infrared wavelength is performed. The results show that, using present-day technology, such a system can be constructed, albeit its usefulness would be restricted to operation under very specific weather conditions.
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MacIntosh, Scott Ian. "Trends and implications of the conversion of single-family dwellings into multiple units in the city of Ottawa." Thesis, University of Ottawa (Canada), 1986. http://hdl.handle.net/10393/4879.
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Dukhno, Oleksii. "Microscopie de molécules uniques avec des nanoparticules à conversion ascendante." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAJ104.
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La microscopie de molécule unique (single-molecule microscopy, SMM) regroupe un ensemble de techniques pour la biologie moléculaire et cellulaire permettant de visualiser le mouvement de molécules biologiques individuelles. Néanmoins, les techniques SMM imposent de fortes contraintes en ce qui concerne les luminophores utilisés. Récemment, un nouveau luminophore appelé «particule à conversion ascendante» (upconverting nanoparticles, UCNP) a attiré l'attention de la communauté scientifique en raison de son émission efficace de lumière visible après une excitation par de la lumière infrarouge. Cette propriété fait des UCNPs un luminophore très intéressant pour les applications biologiques : l'excitation infrarouge permet d'éliminer l’autofluorescence, généralement associé à une excitation dans la gamme du visible. De plus, la photostabilité extrême des UCNP et l’absence de photoclignotement sont également de précieux atouts pour les expériences SMM. L’objectif de cette thèse était d’adapter les UCNPs aux applications SMM, avec le but ultime d’exploiter leurs propriétés uniques pour améliorer les performances des expériences SMM. Au cours du projet, les protocoles de dispersion des UCNPs dans des tampons aqueux ont été optimisées pour conserver une bonne monodispersité des particules; l'efficacité des UCNPs dans les expériences de transfert résonant d'énergie en particule unique a été estimée; des protocoles pour l'imagerie d'UCNPs uniques ont été développés; et la preuve de concept de l'utilisation des UCNPs dans des expériences de suivi de molécules uniques à la surface de cellules vivantes a été réalisée. Finalement, ces résultats forment une base solide pour de futures expériences SMM utilisant les UCNPsSingle-molecule microscopy (SMM) is a powerful set of techniques for molecular and cell biology that allows visualizing the movement of individual biological molecules, but has strict requirements towards the utilized luminophores. Recently, a new luminophore called upconverting particles (UCNPs) gained attention of the research community due to their efficient emission of visible light upon excitation with infrared light. This property makes UCNPs a valuable luminophore for biological applications due to the elimination of autofluorescence background, commonly associated with regular visible light excitation. Extreme photostability of UCNPs and absence of sporadic photoswitching are also valuable for SMM experiments. The objective of this thesis was to adapt UCNPs to SMM applications, with the ultimate goal of exploiting their unique properties towards superior performance of SMM experiments. During the project, protocols for dispersing UCNPs in aqueous buffers were streamlined to provide superior particle monodispersity; the efficiency of UCNPs in single-molecule resonance energy transfer experiments was estimated; protocols for single-molecule imaging with UCNPs were developed; and a proof-of-concept system for targeted single-molecule tracking with UCNPs in live cells was demonstrated. Overall, these findings will serve as a foundation towards robust SMM assays based on UCNPs
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Hsu, Mark J. "Development of shallow trench isolation bounded single-photon avalanche detectors for acousto-optic signal enhancement and frequency up-conversion." Diss., [La Jolla] : University of California, San Diego, 2010. http://wwwlib.umi.com/cr/ucsd/fullcit?p3407959.
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Thesis (Ph. D.)--University of California, San Diego, 2010.Title from first page of PDF file (viewed June 17, 2010). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (leaves 172-191).
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Garriss, Timothy Paul. "Bridge-house : a new residential building typology for affordable work-centered housing." Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/23173.
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McGuinness, Hayden James 1980. "The creation and frequency translation of single-photon states of light in optical fiber." Thesis, University of Oregon, 2011. http://hdl.handle.net/1794/11259.
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xiii, 164 p. : ill. (some col.)We explore the frequency translation of single-photon states of light and the creation of photon pairs by four-wave mixing in optical fiber. Frequency translation refers to changing the central frequency of a field, while photon pair creation refers to the creation of two individual photons at the same time. We demonstrate these effects in third-order nonlinear optical fiber. While both phenomena have previously been shown by three-wave mixing in second-order nonlinear media, there are compelling reasons to develop these tasks in third-order media. Most importantly, frequency translation in third-order material allows for the practical implementation of both small and large frequency shifts, while second-order material only practically allows for large shifts. Photon creation in third-order media often permits more flexible phase-matching conditions, allowing for the creation of a wider variety of quantum states than is often possible in second-order media. In our theoretical study of photon pair creation, we focus on the spectral correlations of the photon pairs. We pay particular attention to the creation of quantum states of high purity, where the photons are not spectrally correlated with one another. High purity photons are a requisite resource for several different quantum information processing applications, such as linear-optical quantum computing. We find that states with high purity can be realized with a minimal amount of spectral filtering. Experimentally, we study photon frequency translation in photonic crystal fiber. The central wavelength of the input photons was translated from 683 nm to 659 nm. We perform second-order intensity correlation measurements on both channels to demonstrate their quantum nature. This resulted in values of 0.21 ± 0.02 and 0.19 ± 0.05 for the 683-nm and 659-nm channels, respectively, demonstrating that those fields were dominated by their single-photon component. The efficiency at which the process occurred was 29 percent. Theoretically, we develop a Green function formalism to describe the translation process and develop a computational model to calculate the solution to the governing equations. Also, in a related experiment, we demonstrate classical frequency translation from 851 nm to 641 nm, a record translation in both wavelength and frequency, at an efficiency of 0.2 percent in a birefringent fiber.
Committee in charge: Dr. Daniel Steck, Chair; Dr. Michael Raymer, Advisor; Dr. Steven van Enk, Inside Member; Dr. Raghuveer Parthasarathy, Inside Member; Dr. Andrew Marcus, Outside Member
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Ruokamo, S. (Simo). "Single shared model approach for building information modelling." Doctoral thesis, Oulun yliopisto, 2019. http://urn.fi/urn:isbn:9789526223704.
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Abstract The current practice for information sharing with building information modelling (BIM) is distributed data sharing based on conversions. Conversions are problematic due to data loss, redundancy, and conflicting information. The hypotheses of this research were that i) a conversion-free data exchange is a feasible approach for BIM, ii) benefits can be achieved with a conversion-free information sharing, and iii) no impediment in principle exists for wider industrial use. The use of a single data schema by all applications is a requisite for a conversion-free data collaboration. For enabling the free evolution of the data content, a version free data schema is necessary. A model arrangement implementing partial models is needed for the growing size of models. A single shared model approach eliminates data conflicts and duplicates. For the best availability, the location for the shared model should be on a cloud service. Accessing the cloud model only through a web service, which encapsulates all model handling functionality, will ensure data integration and validity. The validity of IT solutions can only be confirmed with real software. For testing the conversion-free BIM method, a software development kit (SDK) with required functionality was programmed. Three applications and a cloud service for handling the shared model were developed with the help of SDK. In the experiments, Leonardo application was used for modelling walls, 3DTrussme for trusses, and Viewer for viewing the model. All applications were using the same shared model on the cloud. In the experimental test, the information exchange occurred without conversions, and all the data were saved only once on the cloud database. Without conversions, less conflicts and redundancies occurred, which lead to better data integrity and integration. Using SDK, there was no technical barrier for applications to join the single shared model ecosystem, but a drawback was that existing BIM programs are not compatible without remarkable changes. The performance was acceptable in the test run, but in real use, the size of the model and the number of applications and users will be much larger. However, a conversion-free single shared model approach can be a possible trend to the next generation BIM as well as a potential alternative for current data sharing methods using distributed files, conversions, and linked dataTiivistelmä Rakentamisen tietomallinnuksen (BIM) nykyisenä tiedonjakamisen käytäntönä on hajautettu tietojärjestelmä, joka perustuu konversioihin. Konversiot ovat ongelmallisia tiedon häviämisen, ristiriitojen ja päällekkäisyyksien vuoksi. Tämän tutkimuksen hypoteesit olivat: i) konversiovapaa tiedonjakaminen on mahdollista, ii) etuja on saavutettavissa ilman konversioita tapahtuvassa tiedonsiirrossa ja iii) laajemmalle teolliselle käytölle ei ole periaatteellisia esteitä. Konversiovapaa tiedon jakaminen edellyttää yhden dataformaatin käyttöä. Alati kasvavien tietomallien koko vaatii tiedon järjestämismenetelmän, joko mahdollistaa osamallit. Datan ristiriidat ja päällekkäisyydet voidaan estää yhden jaetun mallin menetelmällä. Informaatio on parhaiten kaikkien osapuolien saatavilla, kun jaettu malli sijoitetaan pilvipalveluun. Kun tietomallia käsitellään vain web-palvelun rajapintafunktioilla, tiedon eheys ja kelpoisuus säilyvät. Tietoteknisten ratkaisujen kelpoisuus voidaan viime kädessä osoittaa vain toimivilla ohjelmistoilla. Konversiovapaan menetelmän testausta varten kehitettiin vaadittavat ominaisuudet sisältävä ohjelmistokehityspaketti (SDK), joka on edellytys sovellusten yhteensopivuudelle. Kolme sovellusta eli 3DTrussme, Leonardo ja Viewer ohjelmoitiin SDK:n avulla. Ohjelmointirajapinta sisälsi tarvittavat toiminnallisuudet tiedonjakamiseen, ja se toteutettiin pilvipalveluna. Testiajossa Leonardo-sovelluksella mallinnettiin seinät, 3DTrussmellä suunniteltiin naulalevyristikot ja Viewer-sovelluksella tarkasteltiin mallia. Kaikki kolme sovellusta käyttivät samaa jaettua mallia pilvipalvelussa. Suoritetussa testissä kaikki informaatio jaettiin ilman konversioita ja tallennettiin vain kerran. Ilman konversioita ja päällekkäisyyksiä saavutettiin parempi datan eheys ja integraatio. SDK:n avulla uudet sovellukset pystyivät liittymään yhden jaetun mallin ekosysteemiin ilman teknisiä esteitä. Toisaalta, ilman merkittäviä muutoksia nykyiset BIM sovellukset eivät ole yhteensopivia. Testiajossa suorituskyky oli hyväksyttävä, mutta todellisuudessa mallien koko sekä sovellusten ja käyttäjien lukumäärä ovat paljon suurempia. Tutkimus osoitti, että konversiovapaa yhden jaetun mallin menetelmä voi olla seuraava BIM-kehityssuunta ja vaihtoehto nykyisille tiedonsiirtoratkaisuille, jotka käyttävät erillisiä tiedostoja, konversioita ja linkkejä
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Davenport, Tattiana Karina Coleman. "Three-Phase Generation Using Reactive Networks." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1345.
Full textAbstract:
Household appliances utilize single-phase motors to perform everyday jobs whether it is to run a fan in an air conditioner or the compressor in a refrigerator. With the movement of the world going “green” and trying to make everything more efficient, it is a logical step to start with the items that we use every day. This can be done by replacing single-phase motors with three-phase motors in household appliances. Three-phase motors are 14% more efficient than single-phase motors when running at full load and typically cost less over a large range of sizes [1]. One major downside of incorporating three-phase motors in household appliance is that three-phase power is not readily available in homes. With the motor replacement, a single to three-phase converter is necessary to convert the single-phase wall power into the required three-phase input of the motor. One option is active conversion, which uses switches and introduces different stages that produce power loss [2]. An alternative solution is passive conversion that utilizes the resistances within the motor windings along with additional capacitors and inductors, which in theory are lossless. This study focuses on three different single to three-phase passive converters to run both wye and delta-connected three-phase induction motors, and a possible third winding configuration that utilizes one of the three converters. There will be an emphasis on proving the equivalency of two converters, one proposed by Stuart Marinus and Michel Malengret [11] and the other by Otto Smith [12]. Sensitivity analysis is performed to study the effects of variation of torque and converter component tolerances on the system.
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Ahlrichs, Andreas. "Triply-Resonant Cavity-Enhanced Spontaneous Parametric Down-Conversion." Doctoral thesis, Humboldt-Universität zu Berlin, 2019. http://dx.doi.org/10.18452/20150.
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Die verlässliche Erzeugung einzelner Photonen mit wohldefinierten Eigenschaften in allen Freiheitsgraden ist entscheidend für die Entwicklung photonischer Quantentechnologien. Derzeit basieren die wichtigsten Einzelphotonenquellen auf dem Prozess der spontanen parameterischen Fluoreszenz (SPF), bei dem ein Pumpphoton in einem nichtlinearen Medium spontan in ein Paar aus Signal und Idlerphotonen zerfällt. Resonator-überhöhte SPF, also das Plazieren des nichtlinearen Mediums in einem optischen Resonator, ist ein weit verbreitetes Verfahren, um Einzelphotonenquellen mit erhöhter Helligkeit und angepassten spektralen Eigenschaften zu konstruieren. Das Anpassen der spektralen Eigenschaften durch gezielte Auswahl der Resonatoreigenschaften ist besonders für hybride Quantentechnologienvon Bedeutung, welche darauf abzielen, unterschiedliche Quntensysteme so zu kombinieren, dass sich deren Vorteile ergänzen. Diese Arbeit stellt eine umfassende theoretische und experimentelle Analyse der dreifach resonanten SPF vor. Das aus der Literatur bekannte theoretische Modell wird diesbezüglich verbessert, dass der Einfluss sämtlicher Eigenschaften des Resonators auf die wichtigen experimentellen Größen (z.B. die Erzeugungsrate) gezielt ausgewertet werden kann. Dieses verbesserte und hoch genaue Modell stellt eine wichtige Grundlage für die Entwicklung und Optimierung neuartiger Photonenpaarquellen dar. Im experimentellen Teil dieser Arbeit wird der Aufbau und die Charakterisierung einer dreifach resonanten Photonenpaarquellen präsentiert. Die neu entwickelte digitale Regelelektronik sowie ein hochstabiler, schmalbandiger Monochromator welcher auf monolitischen, polarisationsunabhängigen Fabry-Pérot Resonatoren basiert, werden vorgestellt. Indem diese temperaturstabilisierten Resonatoren als Spetrumanalysator verwendet werden, wird zum ersten Mal die Frequenzkammstruktur des Spektrums der erzeugten Signal- und Idlerphotonen nachgewiesen. Des Weiteren wird der Einfluss der Pumpresonanz auf die Korrelationsfunktion und die Zweiphotoneninterferenz von Signal- und Idlerphotonen simuliert und vermessen. Abschließend werden Experimente aus dem Bereich der hybriden Quantennetzwerke präsentiert, in welchen Quantenfrequenzkonversion verwendet wird um die erzeugten Signalphotonen in das Telekommunikationsband zu transferieren. Dabei wird nachgewiesen, dass das temporale Wellenpaket durch die Konversion nicht beeinflusst wird und aufgezeigt, wie Quantennetzwerke von kommerziellen Telekommunikationstechnologien profitieren können.The consistent generation of single photons with well-defined properties in all degrees of freedom is crucial for the development of photonic quantum technologies. Today, the most prominent sources of single photons are based on the process of spontaneous parametric down-conversion (SPDC) where a pump photon spontaneously decays into a pair of signal and idler photons inside a nonlinear medium. Cavity-enhanced SPDC, i.e., placing the nonlinear medium inside an optical cavity, is widely used to build photon-pair sources with increased brightness and tailored spectral properties. This spectral tailoring by selective adjustment of the cavity parameters is of particular importance for hybrid quantum technologies which seek to combine dissimilar quantum systems in a way that their advantages complement each other. This thesis provides a comprehensive theoretical and experimental analysis of triply-resonant cavity-enhanced SPDC. We improve the theoretical model found in the literature such that the influence of all resonator properties on the important experimental parameters (e.g., the generation rate) can be analyzed in detail. This convenient and highly accurate model of cavity-enhanced SPDC represents an important basis for the design and optimization of novel photonpair sources. The experimental part of this thesis presents the setup and characterization of a triply-resonant photon-pair source. We describe the digital control system used to operate this source over days without manual intervention, and we present a highly stable, narrow-linewidth monochromator based on cascaded, polarization-independent monolithic Fabry-Pérot cavities. Utilizing these temperature-stabilized cavities as a spectrum analyzer, we verify, for the first time, the frequency comb spectral structure of photons generated by cavity-enhanced SPDC. We further simulate and measure the impact of the pump resonance on the temporal wave-packets and the two-photon interference of signal and idler photons. Finally, we present a series of experiments in the context of hybrid quantum networks where we employ quantum frequency conversion (QFC) to transfer the generated signal photons into the telecommunication band. We verify the preservation of the temporal wave-packet upon QFC and highlight how quantum networks can benefit from advanced commercial telecommunication technologies.
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Höckel, David. "Narrow-band single photons as carriers of quantum information." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2011. http://dx.doi.org/10.18452/16255.
Full textAbstract:
Die Nutzung von Quanteneigenschaften für die Informationsverarbeitung, die sogenannte Quanteninformationsverarbeitung (QIP), ist ein seit zwei Jahrzehnten zunehmend populäres Forschungsfeld. Es hat sich gezeigt, dass Einzelphotonen die am besten geeigneten Träger für den Transport von Quanteninformation über weite Strecken sind. Obwohl viele Methoden zur Erzeugung von Einzelphotonen existieren, wurde bisher nur wenig Forschungsarbeit an schmalbandigen Einzelphotonen, d.h. mit spektralen Breiten im MHz-Bereich geleistet. Allerdings sind solche Einzelphotonen besonders wichtig, wenn Kopplungen zwischen Einzelphotonen und atomaren Systemen, die oft als Verarbeitungseinheiten in der QIP genutzt werden, realisiert werden sollen. Diese Doktorarbeit befasst sich mit mehreren Forschungsaspekten zu schmalbandigen Einzelphotonen, die von Bedeutung sind, wenn solche Photonen als Informationsträger genutzt werden sollen. Zunächst wird eine Quelle von schmalbandigen Einzelphotonen vorgestellt, die auf dem Konzept der parametrischen Fluoreszenz innerhalb eines optischen Resonators basiert und die einen konstanten Strom von Photonenpaaren emittiert. Eine statistische Beschreibung dieser Photonenpaare wird vorgestellt und erstmals direkt gemessen. Um Emission in nur eine einzelne Mode zu erreichen, wurde der Photonenstrom mit Hilfe eines speziell entwickelten Mehrpass-Fabry-Perot-Etalons mit geringem Durchlassbereich und sehr hohem Kontrast gefiltert. Photon-Atom-Wechselwirkungen werden im zweiten Teil der Arbeit gezeigt. Der Effekt der elektromagnetisch induzierten Transparenz (EIT) wird vorgestellt und experimentell demonstriert. Die ersten EIT Experimente in Cäsiumgaszellen bei Raumtemperatur mit Probepulsen, die nur ein einzelnes Photon enthalten, werden demonstriert. Schließlich zeigt ein umfassender Ausblick wie die entwickelten experimentellen Bausteine erweitert werden können, um Einzelphotonenspeicherung zu erlauben und die Technologie für Quantenrepeater zu demonstrieren.The use of quantum mechanical properties for information processing, so-called quantum information processing (QIP) has become an increasingly popular research field in the last two decades. It turned out that single photons are the most reliable long distance carriers of quantum information, e.g., tools to connect different processing nodes in QIP. While several methods exist to produce single photons, only little research has been performed so far on narrow-band single photons with spectral bandwidths in the MHz regime. Such photons are, however, of particular importance when coupling of single photons to atomic systems, which are often used in QIP as processing nodes, shall be realized. This thesis covers several research aspects on narrow-band single photons, all of which are important if such photons should be used as quantum information carriers. At first, a source for narrow-band single photons is introduced. This source is based on the concept of parametric down-conversion inside an optical resonator. It emits a constant stream of photon pairs. One of the two photons from the pair can be detected heralding the presence of the other photon. A statistical description of these photon pairs is introduced and for the first time also directly measured. In order to reach single-mode single-photon emission, the stream of photons was filtered with a specifically developed multi-pass Fabry-Perot etalon. This filter has a passband FWHM of only 165 MHz and particularly high contrast.
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Cheng, Yongjie. "Design and Realization of a Single Stage Sigma-Delta ADC With Low Oversampling Ratio." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1561.pdf.
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Ozkan, Ziya. "Leakage Current And Energy Efficiency Analyses Of Single Phase Grid Connected Multi-kva Transformerless Photovoltaic Inverters." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614236/index.pdf.
Full textAbstract:
In order to inject solar power to the utility grid, among various types of inverters, Grid Connected Transformerless Solar Inverters (GCTSI) are mostly preferred for residential or commercial applications. This preference is because of the high energy efficiency and low cost due to the absence of a line frequency or a high frequency transformer. Peak value of the efficiency characteristics of GCTSIs can reach 98%, which are selected topology, component optimization, switching strategy and operating condition dependent. In spite of the attractive energy efficiency characteristics of GCTSIs, due to the lack of galvanic isolation, these inverters are vulnerable to leakage currents, which are prohibitive for the safety and the maintenance reasons. The purpose of this research is to analyze GCTSIs in terms of their leakage current and energy efficiency characteristics. In the research, the leakage current mechanisms of GCTSIs are identified and grid connected solar inverters are classified in terms of their leakage current characteristics including the GCTSIs. In addition to the existing ones, several novel topologies are proposed enriching the family of GCTSIs. The leakage current and the inductor current ripple performances of GCTSI topologies are analyzed and evaluated by detailed simulations for 3 kVA and 10 kVA single-phase systems. In addition, the energy efficiency characteristics of GCTSIs are investigated in these power levels by making use of Calculated Average Power Per Switching Cycle (CAPPSC) method. The efficiency studies with CAPPSC method provide design guidelines and comparison of the GCTSI topologies in terms of their energy efficiency characteristics.
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Unal, Teoman. "Design Of A Single-phase Full-bridge Diode Rectifier Power Factor Corrector Educational Test System." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/2/12608148/index.pdf.
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In this thesis an educational test bench for studying the power quality attributes of the
commonly used single-phase full-bridge diode rectifiers with power factor correction
(PFC) circuits is designed and tested. This thesis covers the active and passive power
factor correction methods for single-phase bridge rectifier. Passive filtering approach
with dc side inductor and tuned filter along with active filtering approach via singleswitch
boost converter is considered. Analysis, simulation, and design of a single phase
rectifier and PFC circuits is followed by hardware implementation and tests. In the active
PFC approach, various control methods is applied and compared. The educational bench
is aimed to useful for undergraduate and graduate power electronics course, power
quality related laboratory studies.
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Schunk, Gerhard [Verfasser], Gerd [Akademischer Betreuer] Leuchs, Hugues de [Gutachter] Riedmatten, and Christoph [Gutachter] Marquardt. "Tunable single photons from resonant parametric down-conversion for efficient photon-atom coupling / Gerhard Schunk ; Gutachter: Hugues de Riedmatten, Christoph Marquardt ; Betreuer: Gerd Leuchs." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2018. http://d-nb.info/1160444250/34.
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Wang, Yu-Chih, and 王昱智. "Algorithm and VLSI Architecture of Wavelet-Based Rendering Engine for Stereo-to-Multiview Conversion System." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/835bxn.
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Yao-hui, Wang, and 王耀輝. "Three-Phase/Single-Phase Power Conversion System." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/15613927553968646833.
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碩士崑山科技大學
電機工程研究所
95
In this thesis, a three-phase/single-phase power conversion system is developed. The three-phase/single-phase power conversion system is configured by a power converter, a zero-sequence transformer set and a filter capacitor. The three-phase/single-phase power conversion system can be applied to the three-phase distribution power system to perform a single-phase power conditioner. In this application, the three-phase/ single-phase power conversion system absorbs a real power from the three-phase distribution power system, and it will perform the functions of three-phase balance, low harmonic distortion and unity power factor in spite of single-phase load used. Moreover, the three-phase/single-phase power conversion will supply a single-phase voltage with high power quality for supplying power to the single-phase load. The three-phase/ single-phase power conversion system can also be applied to the small capacity wind power generation system for converting the unregulated three-phase power to a high quality single-phase power and being injected to the single-phase distribution power system. In this application, the three-phase/single-phase power conversion system can perform the functions of three-phase current balance, low harmonic distortion and unity power factor for operating the three-phase power generator smoothly, and a new maximum power point tracking method is developed to extract the maximum power of small-capacity wind power system. Additionally, the three-phase/single-phase power conversion system can also generate a current which is sinusoidal and in phase with the voltage to the single-phase distribution power system. Since the proposed three-phase/single-phase power conversion system contains only one power converter, it has the advantages of simplifying the power circuit and control circuit.
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Lu, Wei-Tso, and 盧唯佐. "Single-Phase/Three-Phase Power Conversion System." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/w6edtd.
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碩士崑山科技大學
電機工程研究所
96
In this thesis, a single-phase/three-phase power conversion system is developed. The single-phase/three-phase power conversion system is configured by a three-phase four-wire power converter, a zero-sequence transformer set and a filter capacitor. The single-phase/three-phase power conversion system is applied to the single-phase distribution power system to perform a three-phase power conditioner. The current-mode control is applied to control the three-phase four-wire power converter so as to generate a positive-sequence current and a zero-sequence current. The positive-sequence current is used to generate the high-quality three-phase voltage suppling to the load. The zero-sequency current is passed to the single-phase distribution power system through the zero-sequency transformer such that the input current of single-phase/three-phase power conversion system is sinusoidal and in phase with the voltage of single-phase distribution power system. Since the proposed single-phase/three-phase power conversion system is configured by only one power converter, it has the advantages of simplifying the power circuit and control circuit. For verifing the performance of the proposed single-phase/three-phase power conversion system, a DSP-based hardware prototype is established and test.
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Kuo, Yeong Chau, and 郭永超. "Design and implementation of single stage photovoltaic energy conversion system." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/07693979424730909919.
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博士國立成功大學
電機工程學系
89
As opposed to conventional two-stage designs, a single stage photovoltaic (PV) energy conversion system is implemented, resulting in size and weight reduction and increased efficiency. The nonlinear output power relation of versus and the near linear relation of versus are discussed. Using as an index for current control is easier than voltage control, allowing a simpler design. The proposed current controller allows a PV energy conversion system to track the maximum power point very rapidly and smoothly. In addition, single current loop controller simplifies the conventional double loop design. The proposed controller performs maximum power point tracking (MPPT) and provides power to utilities with a unity power factor. Further, the proposed controller architecture is employed to the single-phase three-wire photovoltaic energy conversion system. The proposed system employs a three-leg inverter to control the MPPT process, the line current and neutral line current. A neutral line mode controller maintains a utility neutral line current to be zero. A line mode controller controls the line current so as to provide power to the utility with a unity power factor. The proposed system acts as a solar generator on sunny days and functions as an active power filter on rainy or cloudy days. In this thesis, the voltage and current hybrid PWM inverters using fuzzy variable structure control technique is proposed for parallel operation. The voltage-controlled PWM inverter (VCPI) unit is developed to provide a specific sinusoidal output voltage and the current-controlled PWM inverter (CCPI) units are employed to track the distributive current. Each of the VCPI and CCPI units can be operated independently. By using the fuzzy variable structure control scheme, the parallel inverters can provide excellent performance without phase-lock-loop (PLL) circuit for synchronization. The proposed scheme can result in fast dynamic response and robustness to parameter variations. Finally, computer simulations and experimental results demonstrate the superior performance of the proposed technique.