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Синотин, А. М. "Автоматизация расчётов нестационарных тепловых режимов при проектировании одноблочных радиоэлектронных аппаратов". Thesis, ХНУРЕ, 2008. http://openarchive.nure.ua/handle/document/6863.
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Thesis is devoted to the research of heat exchange character in radio electronic vehicles which function in an air environment at normal atmospheric pressure; the development of calculation method of the non-stationary temperature fields of REA with the arbitrary law of change of the power dispersed elements from a temperature and time; the research of influence of structural parameters of vehicle taking into account the anisotropy of the heated areas on a heat-conducting on a general temperature condition.
First, on the basis of the conducted analytical and experimental researches, the algorithm of the thermophysical planning of onesectional radio electronic vehicles is got that allows to provide the set temperature condition on the initial stages of constructing parallell with development of electric chart and choice of element base. It considerably promotes economic efficiency of developments and eliminates the necessity of substantial changes for a construction on results checking calculations and temperature tests.
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Rodrigues, ?dila Priscilla Gomes. "S?ntese e caracteriza??o de ferritas de n?quel dopadas com cobalto e efeito da substitui??o nas suas propriedades magn?ticas." Universidade Federal do Rio Grande do Norte, 2014. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17766.
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Previous issue date: 2014-12-11Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
The ferrite composition Ni1 - xCoxFe2O4 (0 ≤ x ≤ 0.75) were obtained by the method of microwave assisted synthesis and had their structural and magnetic properties evaluated due to the effect of the substitution of Ni by Co. The compounds were prepared: according to the concept of chemical propellants and heated in the microwave oven with power 7000kw. The synthesized material was characterized by absorption spectroscopy in the infrared (FTIR), Xray diffraction (XRD) using the Rietveld refinement, specific surface area (BET) , scanning electron microscopy (SEM) with aid of energy dispersive analysis (EDS) and magnetic measurements (MAV). The results obtained from these techniques confirmed the feasibility of the method of synthesis employed to obtain the desired spinel structure, the ferrite, nickel ferrite as for nickel doped with cobalt. The results from XRD refinement ally showed the formation of secondary phases concerning stages α - Fe2O3, FeO, (FeCo)O e Ni0. On the other hand, there is an increase in crystallite size with the increase of cobalt in systems, resulting in an increased crystallinity. The results showed that the BET systems showed a reduction in specific surface area with the increase of cobalt and from the SEM, the formation of irregular porous blocks and that the concentration of cobalt decreased the agglomerative state of the system. The magnetic ferrites studied showed different characteristics according to the amount of dopant used, ranging from a very soft magnetic material (easy magnetization and demagnetization ) - for the system without cobalt - a magnetic material with a little stiffer behavior - for systems containing cobalt. The values of the coercive field increased with the increasing growth of cobalt, and the values of saturation magnetization and remanence increased up to x = 0,25 and then reduced. The different magnetic characteristics presented by the systems according to the amount of dopant used, allows the use of these materials as intermediates magnetic
As ferritas de composi??o Ni1−xCoxFe2O4 (0≤x≤0,75) foram obtidas atrav?s do m?todo de s?ntese assistida por microondas e tiveram suas propriedades estruturais e magn?ticas avaliadas em fun??o do efeito da substitui??o do Ni pelo Co. Os compostos foram preparados de acordo com o conceito da qu?mica dos propelentes e aquecidos em forno micro-ondas com pot?ncia 7000kw. O material sintetizado foi caracterizado por espectroscopia de absor??o na regi?o do infravermelho (FTIR), difra??o de raios X (DRX), com o uso do refinamento pelo m?todo de Rietveld, ?rea superficial espec?fica (BET), microscopia eletr?nica de varredura (MEV) com aux?lio de an?lise por dispers?o de energia (EDS) e medidas magn?ticas (MAV). Os resultados obtidos, a partir destas t?cnicas confirmaram a viabilidade do m?todo de s?ntese empregado para a obten??o da estrutura espin?lio desejada, tanto para a ferrita de n?quel quanto para as ferritas de n?quel dopadas com cobalto. Os resultados do DRX, aliado ao refinamento, mostraram a forma??o de fases secund?rias tais como as fases α - Fe2O3, FeO, (FeCo)O e Ni0. Por outro lado, observou-se um aumento no tamanho do cristalito com o incremento do cobalto nos sistemas, implicando em um aumento da cristalinidade. Os resultados do BET mostraram que os sistemas apresentaram uma redu??o da ?rea superficial espec?fica com o incremento do cobalto e a partir do MEV observou-se a forma??o de blocos porosos irregulares e que o aumento da concentra??o de cobalto dimunuiu o estado de aglomera??o dos sistemas. As ferritas estudadas apresentaram caracter?sticas magn?ticas diferenciadas de acordo com a quantidade do dopante utilizado, variando de um material magn?tico bastante mole (f?cil magnetiza??o e desmagnetiza??o) - para o sistema sem cobalto - a um material magn?tico com comportamento um pouco mais duro - para os sistemas contendo cobalto. Os valores do campo coercitivo aumentaram com o crescente incremento do cobalto, e os valores de magnetiza??o de satura??o e reman?ncia aumentaram at? x=0,25 e depois reduziram. As caracter?sticas magn?ticas diferenciadas apresentadas pelos sistemas, de acordo com a quantidade de dopante utilizado, permite o uso desses materiais como magn?ticos intermedi?rios
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Pedrosa, Anne Michelle Garrido. "Desenvolvimento de catalisadores bifuncionais de ?xido de zirc?nio modificado por ?xidos de tungst?nio e molibd?nio contendo platina para a rea??o de isomeriza??o de n-parafinas." Universidade Federal do Rio Grande do Norte, 2007. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17802.
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Previous issue date: 2007-10-04Bifunctional catalysts based on zircon oxide modified by tungsten (W = 10, 15 and 20 %) and by molybdenum oxide (Mo= 10, 15 e 20 %) containg platinum (Pt = 1%) were prepared by the polymeric precursor method. For comparison, catalysts the tungsten base was also prepared by the impregnation method. After calcinations at 600, 700 and 800 ?C, the catalysts were characterized by X-ray diffraction, fourier-transform infrared spectroscopy, thermogravimetric and differential thermal analysis, nitrogen adsorption and scanning electron microscopy. The profile of metals reduction was determined by temperature programmed reduction. The synthesized catalysts were tested in n-heptane isomerization. X-ray diffractogram of the Pt/WOx-ZrO2 and Pt/MoOx-ZrO2 catalysts revealed the presence of tetragonal ZrO2 and platinum metallic phases in all calcined samples. Diffraction peaks due WO3 and ZrO2 monoclinic also were observed in some samples of the Pt/WOx-ZrO2 catalysts. In the Pt/MoOx-ZrO2 catalysts also were observed diffraction peaks due ZrO2 monoclinic and Zr(MoO4)2 oxide. These phases contained on Pt/WOx-ZrO2 and Pt/MoOx-ZrO2 catalysts varied in accordance with the W or Mo loading and in accordance with the calcination temperature. The infrared spectra showed absorption bands due O-W-O and W=O bonds in the Pt/WOx-ZrO2 catalysts and due O-Mo-O, Mo=O and Mo-O bonds in the Pt/MoOx-ZrO2 catalysts. Specific surface area for Pt/WOx-ZrO2 catalysts varied from 30-160 m2 g-1 and for the Pt/MoOx-ZrO2 catalysts varied from 10-120 m2 g-1. The metals loading (W or Mo) and the calcination temperature influence directly in the specific surface area of the samples. The reduction profile of Pt/WOx-ZrO2 catalysts showed two peaks at lower temperatures, which are attributed to platinum reduction. The reduction of WOx species was evidenced by two reduction peak at high temperatures. In the case of Pt/MoOx-ZrO2 catalysts, the reduction profile showed three reduction events, which are attributed to reduction of MoOx species deposited on the support and in some samples one of the peak is related to the reduction of Zr(MoO4)2 oxide. Pt/WOx-ZrO2 catalysts were active in the n-heptane isomerization with high selectivity to 3-methyl-hexane, 2,3- dimethyl-pentane, 2-methyl-hexane among other branched hydrocarbons. The Pt/MoOx-ZrO2 catalysts practically didn't present activity for the n-heptane isomerization, generating mainly products originating from the catalytic cracking
Catalisadores bifuncionais a base de ?xido de zirc?nio modificado por ?xidos de tungst?nio (W = 10, 15 e 20 %) ou molibd?nio (Mo= 10, 15 e 20 %) contendo platina (Pt = 1 %) foram preparados pelo m?todo dos precursores polim?ricos. Por compara??o, catalisadores a base de tungst?nio tamb?m foram preparados pelo m?todo de impregna??o. Ap?s calcina??es a 600, 700 e 800 ?C, os catalisadores foram caracterizados por difra??o de raios-X, espectroscopia de absor??o na regi?o do infravermelho, an?lise termogravim?trica, an?lise t?rmica diferencial, adsor??o de nitrog?nio e microscopia eletr?nica de varredura. Os perfis de redu??o dos metais foram determinados por redu??o a temperatura programada. Os catalisadores sintetizados foram testados na isomeriza??o do n-heptano. Os difratogramas de raios-X dos catalisadores Pt/WOx-ZrO2 e Pt/MoOx-ZrO2 revelaram a presen?a do ZrO2 tetragonal e da platina met?lica em todas as amostras calcinadas. Picos de difra??o referentes ao WO3 e ao ZrO2 monocl?nico tamb?m foram observados em algumas das amostras dos catalisadores Pt/WOx-ZrO2. Nos catalisadores do tipo Pt/MoOx-ZrO2 tamb?m foram observados picos de difra??o referente ao ZrO2 monocl?nico e ao ?xido Zr(MoO4)2. O aparecimento destas outras fases contidas nos catalisadores Pt/WOx-ZrO2 e Pt/MoOx-ZrO2 variaram de acordo com o teor de W ou Mo e de acordo com a temperatura de calcina??o. Os espectros de absor??o na regi?o do infravermelho exibiram bandas de absor??o referentes as liga??es O-W-O e W=O nos catalisadores Pt/WOx-ZrO2 e referentes as liga??es O-Mo-O, Mo=O e Mo-O nos catalisadores Pt/MoOx-ZrO2. A ?rea superficial espec?fica dos catalisadores Pt/WOx-ZrO2 variou de 30-160 m2 g-1 e para os catalisadores do tipo Pt/MoOx-ZrO2 variou de 10-120 m2 g-1. O teor de metais (W ou Mo) e a temperatura de calcina??o exercem uma influ?ncia direta no valor da ?rea superficial espec?fica das amostras. Os perfis de redu??o dos catalisadores Pt/WOx-ZrO2 exibiram dois picos a baixas temperaturas, os quais s?o atribu?dos a redu??o da platina. A redu??o das esp?cies WOx foi evidenciada por dois picos de redu??o a altas temperaturas. No caso dos catalisadores Pt/MoOx-ZrO2, os perfis de redu??o mostram tr?s eventos de redu??o, os quais s?o atribu?dos a redu??o das esp?cies MoOx depositadas no suporte e em algumas amostras um dos picos ? relacionado com a redu??o do ?xido Zr(MoO4)2. Os catalisadores Pt/WOx-ZrO2 foram ativos para a isomeriza??o do n-heptano com alta seletividade a 3-metil-hexano, 2,3-dimetil-pentano e 2-metil-hexano entre outros hidrocarbonetos ramificados. Os catalisadores Pt/MoOx- ZrO2 praticamente n?o apresentaram atividade para a isomeriza??o do n-heptano, gerando principalmente produtos oriundos do craqueamento catalitico
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Brookes, Timothy Sean. "A real-time auditory spectograph." Thesis, University of York, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337653.
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Benkrid, A. "Real time TLM vocal tract modelling." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.352958.
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Chand, G. "Real-time digital synthesis of transient waveforms : Complex transient sound waveforms are analysed for subsequent real-time synthesis with variable parameters." Thesis, University of Bradford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376681.
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Holloway, Matthew. "Experimental study of REE carbonate and fluorocarbonate synthesis as a basis for understanding hydrothermal REE mineralisation." Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31162.
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Many of the world's economic rare earth element (REE) deposits are formed from, or have been subsequently upgraded by, hydrothermal fluids. Some of the most important REE minerals are the light REE (LREE) enriched fluorocarbonates and carbonates, which are commonly found in carbonatites. Textural and mineralogical evidence from these and other sites point towards wall rock composition as a major control on the observed REE mineralisation, with the supply of carbonate, and possibly fluoride, thought to be the limiting factor. Despite theoretical and experimental studies focussed on REE speciation in hydrothermal fluids, and a few on REE mineral solubility, there remains a lack of understanding of the processes occurring at the uid-rock interface during REE carbonate and fluorocarbonate mineralisation. Many of the issues surrounding this topic stem from the difficulty of working at elevated temperatures, low REE concentrations, and with the corrosive fluoride ion. The synthesis of REE carbonates under simple, low temperature conditions is a useful starting point for understanding REE mineralisation, and as such has been the focus of research for decades. Despite this, cross-series trends are rarely assessed together under the same conditions, and multi-REE-bearing systems - useful for assessing REE fractionation - have scarcely been explored. Furthermore, wall rock experiments, whereby REE-rich fluids are reacted directly with carbonate rocks, are absent from the literature. The same is true for systems containing fluoride, necessary for studying the formation of fluorocarbonates. A fuller understanding of REE mineralisation cannot be achieved until empirical experimental results can be compared with theoretical data and field observations. This thesis documents the laboratory synthesis of single- and multiple-REE-bearing carbonates and fluorocarbonates, and compares the findings with a mineralogical and textural study of two REE-bearing carbonatite deposits. The REEs La, Nd, Gd, Er and Yb were investigated as representatives of the entire series. The experiments constituted titrations of REE chloride solutions with sodium carbonate, and `wall rock reactions' of REE chloride with dolomite, or dolomite plus fluorite. Batch and flow-through setups were used, and the experiments were performed, or the products aged, at temperatures ranging from ambient to 200 °C. Products were characterised by techniques such as PXRD and SEM to document their structure and morphology as a function of temperature, and assess the influence of single vs multiple REE on the final material (whether mixed or separate phases formed). Results showed that in titration experiments, the LREEs crystallised easily and at low temperatures (as low as room temperature), HREEs either do not crystallise (in some cases even at 200 °C) or are more diffcult to crystallise, and mixed LREE + HREE precipitates behaved more like HREE-only examples. The HREEs and LREEs + HREEs mostly produced X-ray amorphous materials, identified as carbonates using FTIR. These were analysed by XAS (XANES and EXAFS) to assess whether they possessed the same short-range structure as the crystalline phase into which are known to form, thus adding to the non-classical nucleation pathway argument as previously suggested for these materials. Results suggested the short-range order of most phases analysed were similar to known bulk phases, but that these were probably different to the earlier precipitates formed in solution. Additionally, in the mixed LREE + HREE systems (Nd+Er), REEs were well dispersed (as opposed to Nd- and Er-rich clusters). In contrast to the titration results were those of wall rock reactions, in which excellent crystallisation was observed for almost every REE configuration (single- or up to five- REE mix), or ageing duration. All but three of the phases produced were previously described natural or synthetic minerals. When fluorite was included in batch reactions the results were more varied: REE carbonates, fluorides and fluorocarbonates were all observed, but never together in the same sample (except in one example). A textural and mineralogical assessment of two carbonatite deposits, Bayan Obo, China and Tundulu, Malawi, which were analysed by EMPA, revealed multiple stages of hydrothermal activity, some of which related to REE fluorocarbonate mineralisation. REE fluorocarbonates, identified at both sites, were typically LREE enriched. No REE carbonates or fluorides were observed, despite the presence of fluorite (REE-barren) and carbonates at Bayan Obo, and carbonates (low REE content) at Tundulu. However, at both sites apatite contained considerable REE. The REE fluorocarbonates were not solely associated with carbonate wall rocks, although the Ca-REE fluorocarbonate synchysite was only observed in the significantly more carbonate-rock-rich Tundulu samples. At Bayan Obo, bastnasite and huanghoite (Ba-REE fluorocarbonate) were observed, the latter of which is reportedly replacing earlier Ca-REE fluorocarbonates. The results demonstrate the varying behaviour of REEs during precipitation under different conditions, and highlights the influence of dissolved carbonate supply rate to morphology, structure and crystallinity of the products. The occurrence of only one class of REE mineral (carbonate, fluoride or fluorocarbonate) in the synthetic experiments with fluoride may help explain the lack of natural REE carbonates and fluorides - and predominance of REE fluorocarbonates - in hydrothermal systems, as was observed in the natural samples studied. In addition, the lack (absence?) of naturally occurring HREE carbonates and fluorocarbonates in the studied carbonatites (and the literature) is suggested to result not from factors such as structural constraints, but instead from the relative crustal abundances of the individual REEs. It is shown that HREE carbonates and fluorocarbonates are valid species under certain conditions, but that these are not likely to occur naturally.
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Zita, Andreas. "Computational Real-Time Sound Synthesis of Rain." Thesis, Linköping University, Department of Science and Technology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1830.
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Real-time sound synthesis in computer games using physical modeling is an area with great potential. To date, most sounds are pre-recorded to match a certain event. Instead by using a model to describe the sound producing event, a number of problems encountered when using pre-recorded sounds can be avoided. This thesis will introduce these problems and present a solution. The thesis will also evaluate one such physical model, for rain sound, and implement a real- time simulation to demonstrate the advantages of the method.
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Sorensen, Matthew J. "Real-time Image Enhancement Using Texture Synthesis." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd595.pdf.
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Jenkins, Mark Daniel. "Synthesis and alternating automata over real time." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:f37ccc5f-8ed6-4b00-b9e3-28c4bb4ec60a.
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Alternating timed automata are a powerful extension of classical Alur-Dill timed automata that are closed under all Boolean operations. They have played a key role, among others, in providing verification algorithms for prominent specification formalisms such as Metric Temporal Logic. Unfortunately, when interpreted over an infinite dense time domain (such as the reals), alternating timed automata have an undecidable language emptiness problem. In this thesis we consider restrictions on this model that restore the decidability of the language emptiness problem. We consider the restricted class of safety alternating timed automata, which can encode a corresponding Safety fragment of Metric Temporal Logic. This thesis connects these two formalisms with insertion channel machines, a model of faulty communication, and demonstrates that the three formalisms are interreducible. We thus prove a non-elementary lower bound for the language emptiness problem for 1-clock safety alternating timed automata and further obtain a new proof of decidability for this problem. Complementing the restriction to safety properties, we consider interpreting the automata over bounded dense time domains. We prove that the time-bounded language emptiness problem is decidable but non-elementary for unrestricted alternating timed automata. The language emptiness problem for alternating timed automata is a special case of a much more general and abstract logical problem: Church's synthesis problem. Given a logical specification S(I,O), Church's problem is to determine whether there exists an operator F that implements the specification in the sense that S(I,F(I)) holds for all inputs I. It is a classical result that the synthesis problem is decidable in the case that the specification and implementation are given in monadic second-order logic over the naturals. We prove that this decidability extends to MSO over the reals with order and furthermore to MSO over every fixed bounded interval of the reals with order and the +1 relation.
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Ferraris, Jonathan William. "Real-time transition texture synthesis for terrains." Thesis, Bournemouth University, 2014. http://eprints.bournemouth.ac.uk/22508/.
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Depicting the transitions where differing material textures meet on a terrain surface presents a particularly unique set of challenges in the field of real-time rendering. Natural landscapes are inherently irregular and composed of complex interactions between many different material types of effectively endless detail and variation. Although consumer grade graphics hardware is becoming ever increasingly powerful with each successive generation, terrain texturing remains a trade-off between realism and the computational resources available. Technological constraints aside, there is still the challenge of generating the texture resources to represent terrain surfaces which can often span many hundreds or even thousands of square kilometres. To produce such textures by hand is often impractical when operating on a restricted budget of time and funding. This thesis presents two novel algorithms for generating texture transitions in realtime using automated processes. The first algorithm, Feature-Based Probability Blending (FBPB), automates the task of generating transitions between material textures containing salient features. As such features protrude through the terrain surface FBPB ensures that the topography of these features is maintained at transitions in a realistic manner. The transitions themselves are generated using a probabilistic process that also dynamically adds wear and tear to introduce high frequency detail and irregularity at the transition contour. The second algorithm, Dynamic Patch Transitions (DPT), extends FBPB by applying the probabilistic transition approach to material textures that contain no salient features. By breaking up texture space into a series of layered patches that are either rendered or discarded on a probabilistic basis, the contour of the transition is greatly increased in resolution and irregularity. When used in conjunction with high frequency detail techniques, such as alpha masking, DPT is capable of producing endless, detailed, irregular transitions without the need for artistic input.
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Nguena-Timo, Omer. "Synthesis for a weak real-time logic." Thesis, Bordeaux 1, 2009. http://www.theses.fr/2010BOR13931/document.
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Dans cette thèse, nous nous intéressons à la spécification et à la synthèse de contrôleurs des systèmes temps-réels. Les modèles pour ces systèmes sont des Event-recording Automata. Nous supposons que les contrôleurs observent tous les évènements se produisant dans le système et qu'ils peuvent interdirent uniquement des évènements contrôlables. Tous les évènements ne sont pas nécessairement contrôlables. Une première étude est faite sur la logique Event-recording Logic (ERL). Nous proposons des nouveaux algorithmes pour les problèmes de vérification et de satisfaisabilité. Ces algorithmes présentent les similitudes entre les problèmes de décision cité ci-dessus et les problèmes de décision similaires étudiés dans le cadre du $\mu$-calcul. Nos algorithmes corrigent aussi des algorithmes présents dans la littérature. Les similitudes relevées nous permettent de prouver l'équivalence entre les formules de ERL et les formules de ERL en forme normale disjonctive. La logique ERL n'étant pas suffisamment expressive pour décrire certaines propriétés des systèmes, en particulier des propriétés des contrôleurs, nous introduisons une nouvelle logique WT$_\mu$. La logique WT$_\mu$ est une extension temps-réel faible du $\mu$-calcul. Nous proposons des algorithmes pour la vérification des systèmes lorsque les propriétés sont écrites en WT$_\mu$. Nous identifions deux fragments de WT$_\mu$ appelés WT$_\mu$ bien guardé ($WG$-WT$_\mu$) et WT$_\mu$ pour le contrôle ($C$-WT$_\mu$). La logique $WG$-WT$_\mu$ est plus expressif que $C$-WT$_\mu$. Nous proposons un algorithme qui permet de vérifier si une formule de $WG$-WT$_\mu$ possède un modèle (éventuellement déterministe). Cet algorithme nécessite de connaître les ressources (horloges et constante maximale comparée avec les horloges) des modèles. Dans le cadre de $C$-WT$_\mu$ l'algorithme que nous proposons et qui permet de décider si une formule possède un modèle n'a pas besoin de connaître les ressources des modèles. En utilisant $C$-WT$_\mu$ comme langage de spécification des systèmes, nous proposons des algorithmes de décision pour le contrôle centralisé et le $\Delta$-contrôle centralisé. Ces algorithmes permettent aussi de construire des modèles de contr\^oleurs. Lorsque les objectifs de contrôle sont décrits à l'aide des formules de $WG$-WT$_\mu$, nous montrons également comment synthétiser des contrôleurs décentralisés avec des ressources fixées à l'avance et ceci, lorsqu'au plus un contrôleur est non déterministeIn this dissertation, we consider the specification and the controller synthesis problem for real-time systems. Our models for systems are kinds of Event-recording automata. We assume that controllers observe all the events occurring in the system and can prevent occurrences of controllable events. We study Event-recording Logic (ERL). We propose new algorithms for the model-checking and the satisfiability problems of that logic. Our algorithms are similar to some algorithms proposed for the same problems in the setting of the standard $\mu$-calculus. They also correct earlier proposed algorithms. We define disjunctive normal form formulas and we show that every formula is equivalent to a formula in disjunctive normal form. Unfortunately, ERL is rather weak and can not describe some interesting real-time properties, in particular some important properties for controllers. We define a new logic that we call WT$_\mu$. The logic WT$_\mu$ is a weak real-time extension of the standard $\mu$-calculus. We present an algorithm for the model-checking problem of WT$_\mu$. We consider two fragments of WT$_\mu$ called well guarded WT$_\mu$ ($WG$-WT$_\mu$) and WT$_\mu$ for control ($C$-WT$_\mu$). We show that the satisfiability of $WG$-WT$_\mu$ is decidable if the maximal constants appearing in models are known a priori. Our algorithm allows to check whether a formula of $WG$-WT$_\mu$ has a deterministic model. The algorithm we propose to decide whether a formula of $C$-WT$_\mu$ has a model does not need to know the maximal constant used in models. All the algorithms for the satisfiability checking construct witness models. Using $C$-WT$_\mu$, we present algorithms for a centralised controller synthesis problem and a centralised $\Delta$-controller synthesis problems. The construction of witness controllers is effective. We also consider the decentralised controller synthesis problem with limited resources (the maximal constants used in controllers is known a priory) when the properties are described with $WG$-WT$_\mu$. We show that this problem is decidable and the computation of witness controllers is effective
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Nilsson, Robin Lindh. "Contact Sound Synthesis in Real-time Applications." Thesis, Blekinge Tekniska Högskola, Institutionen för kreativa teknologier, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3938.
Повний текст джерелаАнотація:
Synthesizing sounds which occur when physically-simulated objects collide in a virtual environment can give more dynamic and realistic sounds compared to pre-recorded sound effects. This real-time computation of sound samples can be computationally intense. In this study we investigate a synthesis algorithm operating in the frequency domain, previously shown to be more efficient than time domain synthesis, and propose a further optimization using multi-threading on the CPU. The multi-threaded synthesis algorithm was designed and implemented as part of a game being developed by Axolot Games. Measurements were done in three stress-testing cases to investigate how multi-threading improved the synthesis performance. Compared to our single-threaded approach, the synthesis speed was improved by 80% when using 8 threads, running on an i7 processor with hyper-threading enabled. We conclude that synthesis of contact sounds is viable for games and similar real-time applications, when using the investigated optimization. 140000 mode shapes were synthesized 30% faster than real-time, and this is arguably much more than a user can distinguish.Syntetisering av ljud som uppstår när fysikobjekt kolliderar i en virtuell miljö kan ge mer dynamiska och realistiska ljudeffekter, men är krävande att beräkna. I det här examensarbetet implementerades ljudsyntes i frekvensdomänen baserat på en tidigare studie, och utvecklades sedan vidare till att utnyttja multipla trådar. Enligt mätningar i tre olika testfall kunde den multitrådade implementationen syntetisera 80% fler ljudvågor än den enkeltrådade, på en i7-processor.
Author's website: www.robinerd.com
14
Jackson, Marcus J. "DESIGN OF A SCREENING PROCESS FOR THE DEVELOPMENT." Master's thesis, Temple University Libraries, 2011. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/202826.
Повний текст джерелаАнотація:
ChemistryM.A.
We have initiated the development of a screening platform to design a library of small molecules on the same solid support surface. This solid support surface, and the chemistry involved, can be utilized as a means of developing lead target molecules, namely ligands and catalysts. Evidence shows the successful assembly of both simple amino acids, as well as successful employment of our synthetic compounds. We support our efforts by showing compatibility for binding studies with larger macromolecules. Thus, intrigue remains by the prospects of this project. Challenges within our efforts are highlighted and emphasis is placed on presenting solutions to current issues, in order to attain further development. Notwithstanding difficulty, the desire to establish efficient processes for the discovery of lead target molecules and to ascertain the utility of our synthesized compounds, can be captured within this body of work. Lastly, the framework for continued efforts has been set to enable future progression.
Temple University--Theses
15
Xiao, Jiangjian. "IMAGE BASED VIEW SYNTHESIS." Doctoral diss., University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3247.
Повний текст джерелаАнотація:
This dissertation deals with the image-based approach to synthesize a virtual scene using sparse images or a video sequence without the use of 3D models. In our scenario, a real dynamic or static scene is captured by a set of un-calibrated images from different viewpoints. After automatically recovering the geometric transformations between these images, a series of photo-realistic virtual views can be rendered and a virtual environment covered by these several static cameras can be synthesized. This image-based approach has applications in object recognition, object transfer, video synthesis and video compression. In this dissertation, I have contributed to several sub-problems related to image based view synthesis. Before image-based view synthesis can be performed, images need to be segmented into individual objects. Assuming that a scene can approximately be described by multiple planar regions, I have developed a robust and novel approach to automatically extract a set of affine or projective transformations induced by these regions, correctly detect the occlusion pixels over multiple consecutive frames, and accurately segment the scene into several motion layers. First, a number of seed regions using correspondences in two frames are determined, and the seed regions are expanded and outliers are rejected employing the graph cuts method integrated with level set representation. Next, these initial regions are merged into several initial layers according to the motion similarity. Third, the occlusion order constraints on multiple frames are explored, which guarantee that the occlusion area increases with the temporal order in a short period and effectively maintains segmentation consistency over multiple consecutive frames. Then the correct layer segmentation is obtained by using a graph cuts algorithm, and the occlusions between the overlapping layers are explicitly determined. Several experimental results are demonstrated to show that our approach is effective and robust. Recovering the geometrical transformations among images of a scene is a prerequisite step for image-based view synthesis. I have developed a wide baseline matching algorithm to identify the correspondences between two un-calibrated images, and to further determine the geometric relationship between images, such as epipolar geometry or projective transformation. In our approach, a set of salient features, edge-corners, are detected to provide robust and consistent matching primitives. Then, based on the Singular Value Decomposition (SVD) of an affine matrix, we effectively quantize the search space into two independent subspaces for rotation angle and scaling factor, and then we use a two-stage affine matching algorithm to obtain robust matches between these two frames. The experimental results on a number of wide baseline images strongly demonstrate that our matching method outperforms the state-of-art algorithms even under the significant camera motion, illumination variation, occlusion, and self-similarity. Given the wide baseline matches among images I have developed a novel method for Dynamic view morphing. Dynamic view morphing deals with the scenes containing moving objects in presence of camera motion. The objects can be rigid or non-rigid, each of them can move in any orientation or direction. The proposed method can generate a series of continuous and physically accurate intermediate views from only two reference images without any knowledge about 3D. The procedure consists of three steps: segmentation, morphing and post-warping. Given a boundary connection constraint, the source and target scenes are segmented into several layers for morphing. Based on the decomposition of affine transformation between corresponding points, we uniquely determine a physically correct path for post-warping by the least distortion method. I have successfully generalized the dynamic scene synthesis problem from the simple scene with only rotation to the dynamic scene containing non-rigid objects. My method can handle dynamic rigid or non-rigid objects, including complicated objects such as humans. Finally, I have also developed a novel algorithm for tri-view morphing. This is an efficient image-based method to navigate a scene based on only three wide-baseline un-calibrated images without the explicit use of a 3D model. After automatically recovering corresponding points between each pair of images using our wide baseline matching method, an accurate trifocal plane is extracted from the trifocal tensor implied in these three images. Next, employing a trinocular-stereo algorithm and barycentric blending technique, we generate an arbitrary novel view to navigate the scene in a 2D space. Furthermore, after self-calibration of the cameras, a 3D model can also be correctly augmented into this virtual environment synthesized by the tri-view morphing algorithm. We have applied our view morphing framework to several interesting applications: 4D video synthesis, automatic target recognition, multi-view morphing.Ph.D.
School of Computer Science
Engineering and Computer Science
Computer Science
16
Wu, Y. "Real-time MIMO detection : algorithm and synthesis technology." Thesis, Queen's University Belfast, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.677852.
Повний текст джерелаАнотація:
MIMO strategy is a key component of modern high throughput wireless communication. Robust detection algorithms are required to retrieve the signals at receiver in MIMO systems. However, these detection algorithms are of remarkable computational complexity and pose a substantial real-time embedded computing problem. Though the real-time solutions on FPGA have enabled such systems, large scale complex architectures are required to do so, demanding detailed manual desigli of circuit architectures. This thesis solves this design problem by addressing synthesis tools for 'Iarge scale detectors on FPGA. A cooperative actor-oriented synthesis (cooperative synthesis) approach is presented, enabling real-time implementations (480 Mbps for IEEE 802.11 n) of the FSD and SSFE detectors, using massively parallel softcore processor networks. This approach has also been applied to a BSS-EFE detector, which eliminates the restrictions and computational redundancies in SSFE to enhance the robustness of algorithm. More than 1 dB SNR gains is achieved with computational complexity reduced by 16:2%. With an alternative ordering approach, complexity may be reduced by 53 :26%. Applying the cooperative synthesis approach, the only recorded realization of this algorithm for IEEE 802.11n is presented.
17
Jun, Yao, and Liu Shi-yan. "Real Time Telemetry Data Synthesis with the TMS320C25." International Foundation for Telemetering, 1992. http://hdl.handle.net/10150/611931.
Повний текст джерелаАнотація:
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, CaliforniaThis paper presents the method of real time telemetry data synthesis for multi-beams and multi-receivers system in theory. For the practical implementation, we introduce a TMS320C25-based data synthesis board. Through a large number of simulating experiments, the satisfactory results are obtained, which obviously improve the performance of telemetry system. Therefore, all those technigues and results have the value of practical applications.
18
Beckett, Keith. "Real-time parallel SAR processing." Thesis, University of Liverpool, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309878.
Повний текст джерела
19
Klein, Joachim. "Compositional Synthesis and Most General Controllers." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-130654.
Повний текст джерелаАнотація:
Given a formal model of the behavior of a system, an objective and some notion of control the goal of controller synthesis is to construct a (finite-state) controller that ensures that the system always satisfies the objective. Often, the controller can base its decisions only on limited observations of the system. This notion of limited observability induces a partial-information game between the controller and the uncontrollable part of the system. A successful controller then realizes an observation-based strategy that enforces the objective.
In this thesis we consider the controller synthesis problem in the linear-time setting where the behavior of the system is given as a nondeterministic, labeled transitions system A, where the controller can only partially observe and control the behavior of A. The goal of the thesis is to develop a compositional approach for constructing controllers, suitable to treat conjunctive cascades of linear-time objectives P_1, P_2, ..., P_k in an online manner. We iteratively construct a controller C_1 for system A enforcing P_1, then a controller C_2 enforcing P_2 for the parallel composition of the first controller with the system, and so on. It is crucial for this approach that each controller C_i enforces P_i in a most general manner, being as permissive as possible. Otherwise, behavior that is needed to enforce subsequent objectives could be prematurely removed.
Standard notions of strategies and controllers only allow the most general treatment for the limited class of safety objectives. We introduce a novel concept of most general strategies and controllers suited for the compositional treatment of objectives beyond safety. We demonstrate the existence of most general controllers for all enforceable, observation-based omega-regular objectives and provide algorithms for the construction of such most general controllers, with specialized variants for the subclass of safety and co-safety objectives.
We furthermore adapt and apply our general framework for the compositional synthesis of most general controllers to the setting of exogenous coordination in the context of the channel-based coordination language Reo and the constraint automata framework and report on our implementation in the verification toolset Vereofy.
The construction of most general controllers in Vereofy for omega-regular objectives relies on our tool ltl2dstar for generating deterministic omega-automata from Linear Temporal Logic (LTL) formulas. We introduce a generic improvement for exploiting insensitiveness to stuttering during the determinization construction and evaluate its effectiveness in practice. We further investigate the performance of recently proposed variants of Safra\'s determinization construction in practice.
20
Cassell, Ryan T. "Synthesis of a PbTx-2 photoaffinity and fluorescent probe and an alternative synthetic route to photoaffinity probes." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1612.
Повний текст джерелаАнотація:
A natural phenomenon characterized by dense aggregations of unicellular photosynthetic marine organisms has been termed colloquially as red tides because of the vivid discoloration of the water. The dinoflagellate Karenia brevis is the cause of the Florida red tide bloom.
K. brevis produces the brevetoxins, a potent suite of neurotoxins responsible for substantial amounts of marine mammal and fish mortalities. When consumed by humans, the toxin causes Neurotoxic Shellfish Poisoning (NSP). The native function of brevetoxin within the organism has remained mysterious since its discovery. There is a need to identify factors which contribute to and regulate toxin production within K. brevis. These toxins are produced and retained within the cell implicating a significant cellular role for their presence.
Localization of brevetoxin and identification of a native receptor may provide insight into its native role as well as other polyether ladder type toxins such as the ciguatoxins, maitotoxins, and yessotoxins. In higher organisms these polyether ladder molecules bind to transmembrane proteins with high affinity. We anticipated the native brevetoxin receptor would also be a transmembrane protein.
Photoaffinity labeling has become increasingly popular for identifying ligand receptors. By attaching ligands to these photophors, one is able to activate the molecule after the ligand binds to its receptor to obtain a permanent linkage between the two. Subsequent purification provides the protein with the ligand directly attached.
A molecule that is capable of fluorescence is a fluorophore, which upon excitation is capable of re-emitting light. Fluorescent labeling uses fluorophores by attaching them covalently to biologically active compounds.
The synthesis of a brevetoxin photoaffinity probe and its application in identifying a native brevetoxin receptor will be described. The preparation of a fluorescent derivative of brevetoxin will be described and its use in localizing the toxin to an organelle within K. brevis. In addition, the general utility of a synthesized photoaffinity label with other toxins having similar functionality will be described.
An alternative synthetic approach to a general photoaffinity label will also be discussed whose goal was to accelerate the preparation and improve the overall synthetic yields of a multifunctional label.
21
Opie, Timothy Tristram. "Creation of a Real-Time Granular Synthesis Instrument for Live Performance." Queensland University of Technology, 2003. http://eprints.qut.edu.au/15865/.
Повний текст джерелаАнотація:
This thesis explores how granular synthesis can be used in live performances. The early explorations of granular synthesis are first investigated, leading up to modern trends of electronic performance involving granular synthesis. Using this background it sets about to create a granular synthesis instrument that can be used for live performances in a range of different settings, from a computer quartet, to a flute duet. The instrument, an electronic fish called the poseidon, is documented from the creation and preparation stages right through to performance.
22
Symons, Peter Robert. "Hardware and algorithm architectures for real-time additive synthesis." Thesis, Open University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418683.
Повний текст джерела
23
Itagaki, Takebumi. "Real-time sound synthesis on a multi-processor platform." Thesis, Durham University, 1998. http://etheses.dur.ac.uk/4890/.
Повний текст джерелаАнотація:
Real-time sound synthesis means that the calculation and output of each sound sample for a channel of audio information must be completed within a sample period. At a broadcasting standard, a sampling rate of 32,000 Hz, the maximum period available is 31.25 μsec. Such requirements demand a large amount of data processing power. An effective solution for this problem is a multi-processor platform; a parallel and distributed processing system. The suitability of the MIDI [Music Instrument Digital Interface] standard, published in 1983, as a controller for real-time applications is examined. Many musicians have expressed doubts on the decade old standard's ability for real-time performance. These have been investigated by measuring timing in various musical gestures, and by comparing these with the subjective characteristics of human perception. An implementation and its optimisation of real-time additive synthesis programs on a multi-transputer network are described. A prototype 81-polyphonic-note- organ configuration was implemented. By devising and deploying monitoring processes, the network's performance was measured and enhanced, leading to an efficient usage; the 88-note configuration. Since 88 simultaneous notes are rarely necessary in most performances, a scheduling program for dynamic note allocation was then introduced to achieve further efficiency gains. Considering calculation redundancies still further, a multi-sampling rate approach was applied as a further step to achieve an optimal performance. The theories underlining sound granulation, as a means of constructing complex sounds from grains, and the real-time implementation of this technique are outlined. The idea of sound granulation is quite similar to the quantum-wave theory, "acoustic quanta". Despite the conceptual simplicity, the signal processing requirements set tough demands, providing a challenge for this audio synthesis engine. Three issues arising from the results of the implementations above are discussed; the efficiency of the applications implemented, provisions for new processors and an optimal network architecture for sound synthesis.
24
Woźniak, Ernest. "Model-based Synthesis of Distributed Real-time Automotive Architectures." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112145/document.
Повний текст джерелаАнотація:
Les solutions basées sur le logiciel/matériel jouent un rôle important dans le domaine de l'automobile. Il est de plus en plus fréquent que l’implémentation de certaines fonctions jusqu’ici réalisées par des composants mécaniques, se fasse dans les véhicules d’aujourd’hui par des composants électroniques embarquant du logiciel. Cette tendance conduit à un grand nombre de fonctions implémentées comme un ensemble de composants logiciels déployés sur unités de commande électronique (ECU). Par conséquent, la quantité de code embarqué dans les automobiles est estimée à des dizaines de giga-octets et le nombre d’ECU de l’ordre de la centaine. Les pratiques actuelles de développement deviennent donc inefficaces et sont en cours d’évolution. L'objectif de cette thèse est de contribuer aux efforts actuels qui consistent à introduire l’utilisation de l'Ingénierie Dirigée par les Modèles dans la conception d’architectures automobiles basées sur le logiciel/matériel. Une première série de contributions de cette thèse porte sur la proposition de techniques pour soutenir les activités décrites dans la méthodologie automobile établie par le langage EAST-ADL2 et le standard AUTOSAR dont l’objectif principal est l'intégration de l'architecture logicielle avec la plate-forme matérielle. Bien que de nombreux travaux sur la synthèse d’architectures existent, cette thèse met en exergue les principaux défauts les empêchant de pleinement supporter la méthodologie EAST-ADL2/AUTOSAR et propose de nouvelles techniques aidant à surmonter les déficiences actuelles. Une deuxième série de contributions concerne les approches de modélisation. L'utilisation de langages de modélisation généralistes (dans le sens non spécifique à un domaine industriel donné) comme SysML et MARTE bien que bénéfique, n'a pas encore trouvé une manière d'être pleinement exploité par les constructeurs automobiles. Cela concerne en particulier la modélisation d’une spécification analysable et l'optimisation des préoccupations qui permettrait d’effectuer des analyses et optimisations à base de modèles. Ce travail définit une méthodologie et les concepts nécessaires à la construction de modèles d'analyse et d'optimisation de ces systèmesHardware/software based solutions play significant role in the automotive domain. It is common that the implementation of certain functions that was done in a mechanical manner, in nowadays cars is done through the software and hardware. This tendency lead to the substantial number of functions operating as a set of software components deployed into hardware entities, i.e. Electronic Control Units (ECU). As a consequence the capacity of the overall code is estimated as tens of gigabytes and the number of ECUs reaches more than 100. Consequently the industrial state of the practice development approaches become inefficient. The objective of this thesis is to add to the current efforts trying to employ the Model Driven Engineering (MDE) in the context of the automotive SW/HW architectures design. First set of contributions relates to the guided strategies supporting the key engineering activities of the automotive methodology established by the EAST-\ADL2 language and the AUTOSAR standard. The main is the integration of the software architecture with the hardware platform. Although the amount of work on the synthesis is substantial, this thesis presents shortcomings of the existing approaches that disable them to fully support the EAST-ADL2/AUTOSAR methodology and delivers new techniques overcoming the current deficiencies. Second contribution concerns approaches for the modeling. Surprisingly the usage of general purpose modeling languages such as the SysML and MARTE although beneficial, haven’t found its way yet to be fully exploited by the automotive OEMs (Original Equipment Manufacturer). This especially relates to the modeling of the analyzable input and the optimization concerns which would enable triggering of the analysis and optimization directly from the models level. This work shows a way and defines additional concepts, necessary to construct analysis and optimization models
25
Berkowitz, Phillip. "A STATISTICAL APPROACH TO VIEW SYNTHESIS." Master's thesis, University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2450.
Повний текст джерелаАнотація:
View Synthesis is the challenging problem of predicting a new view or pose of an object given an exemplar view or set of views. This thesis presents a novel approach for the problem of view synthesis. The proposed method uses global features rather than local geometry to achieve an effect similar to that of the well known view morphing method . While previous approaches to the view synthesis problem have shown impressive results, they are highly dependent on being able to solve for epipolar geometry and therefore have a very precise correspondence between reference images. In cases where this is not possible such as noisy data, low contrast data, or long wave infrared data an alternative approach is desirable. Here two problems will be considered. The proposed view synthesis method will be used to synthesis new views given a set of reference views. Additionally the algorithm will be extended to synthesis new lighting conditions and thermal signatures. Finally the algorithm will be applied toward enhancing the ATR problem by creating additional training data to increase the likelihood of detection and classification.M.S.E.E.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering MSEE
26
Vick, Erik. "IMPLEMENTING LEXICAL AND CREATIVE INTENTIONALITY IN SYNTHETIC PERSONALITY." Doctoral diss., University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3252.
Повний текст джерелаАнотація:
Creating engaging, interactive, and immersive synthetic characters is a difficult task and evaluating the success of a synthetic character is often even more difficult. The later problem is solved by extending Turing's Imitation Game thusly: computational construct should be evaluated based on the criteria of how well the character can mimic a human. In order to accomplish a successful evaluation of the proposed metric, synthetic characters must be consistently believable and capable of role-appropriate emotional expression. The author believes traditional synthetic characters must be improved to meet this goal. For a synthetic character to be believable, human users must be able to perceive a link between the mental state of the character and its behaviors. That is to say, synthetic characters must possess intentionality. In addition to intentionality, the mental state of the character must be human-like in order to provide an adequate frame of reference for the human users' internal simulations, to wit, the character's mental state must be comprised of a synthetic model of personality, of personality dynamics, and of cognition, each of which must be psychologically valid and of sufficient fidelity for the type of character represented. The author proposes that synthetic characters possessing these three models are more accurately described as synthetic personalities. The author proposes and implements computational models of personality, personality dynamics, and cognition in order to evaluate the psychological veracity of these models and computational equivalence between the models and the implementation as a first step in the process of creating believable synthetic personalities.Ph.D.
Other
Arts and Sciences
Modeling and Simulation
27
Patel, Chetak. "ROOM TEMPERATURE SYNTHESIS AND SYSTEMATIC CHARACTERIZATION OF ULTRA-SMALL CERIA NANOPARTICLES." Master's thesis, University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4354.
Повний текст джерелаАнотація:
Cerium oxide (ceria, CeO₂) is a rare earth oxide that has attracted wide-spread research interest because of its unique properties such as high mechanical strength, oxygen ion conductivity, oxygen storage capacity and autocatalytic property. In recent years, researchers have discovered that ceria nanoparticles (NPs) are capable of protecting cells from free radical induced damage. Interestingly, it was found that nanometer size (~ 5 nm) ceria can scavenge free radicals quite efficiently, thus acting as an anti-oxidant. This phenomenon has been explained based on the autocatalytic property of ceria NPs. Several methods have been developed for the synthesis of ceria NPs that include flame combustion, hydroxide co-precipitation, hydrothermal/solvothermal, microemulsion, sonochemical and microwave-assisted heating methods and sol-gel method. Ceria NPs synthesized by these methods are often highly aggregated. Furthermore, large scale synthesis of monodispersed CeO₂ NPs is quite challenging. Therefore it is desirable to synthesize ceria NPs in bulk quantity keeping its important properties intact, specifically free-radical scavenging property. The main goal of this study is therefore to synthesize ultra-small ([less than]5.0 nm), high quality monodispersed ceria NPs in large quantities. In this thesis work, I present a couple of room temperature techniques, dilute sodium hydroxide (NaOH) assisted and ethylenediamine (EN) assisted for the synthesis of nearly mono-dispersed, ultra-small ([less than]5 nm) and water-dispersible ceria NPs. Morphology and particle size of the ceria NPs were investigated through high resolution transmission electron microscopy (HRTEM). The HRTEM analysis confirmed the formation of 3.0 ± 0.5 nm size and 2.5 ± 0.2 nm size highly-crystalline ceria NPs when synthesized using dilute NaOH and EN as solvents, respectively.
The nanostructures were characterized by X-ray diffraction (XRD) studies to determine the crystal structure and phase purity of the products. The samples were also thoroughly characterized by X-ray photoelectron spectroscopy (XPS) to determine the oxidation state of cerium ions. The presence of the +3 and +4 oxidation states in the samples was also confirmed from the XPS analysis. The co-existence of these two oxidation states is necessary for their applications as free radical scavenger. The autocatalytic behaviors of the ceria NPs were investigated through a hydrogen peroxide test and monitored by UV-visible transmission spectroscopy.M.S.
Department of Chemistry
Sciences
Industrial Chemistry MS
28
wei, yun. "SYNTHESIS AND CHARACTERIZATION OF POLYMER-DERIVED POROUS SICN CERAMICS." Master's thesis, University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3566.
Повний текст джерелаАнотація:
The synthesis and characterization of porous SiCN ceramics produced by the method of polymer-derived ceramics were studied in this work. The polymer-to-ceramic conversion technique is a novel revolution in the methods for fabricating porous materials with controlled morphologies and tailored properties. The porous SiCN ceramics can be successfully prepared from thermal decomposition of polymeric precursors (polysilazane) and the pore former (polyvinyl alcohol (PVA)). The fabrication procedures involved the mixing of the pre-ceramic precursor with appropriate concentration of the PVA, curing, pyrolysis and subsequent PVA removal, leaving pores in the ceramic matrix. The material obtained revealed a homogeneous amorphous microstructure consisting of Si, C and N elements. The effects of the concentration and the particle size of PVA on the bulk density, open porosity, line shrinkage, microstructure, pore size, permeability, mechanical behavior, oxidation behavior and thermal stability were examined in this thesis. An increase in both concentration and particle size of PVA contribute to a decrease in the bulk density and an increase in the open porosity and line shrinkage. The morphology development, in particular, was investigated by scanning electron microscopy (SEM). The properties in terms of the pore size and permeability were measured by the water expulsion method. The mechanical behavior of the porous SiCN ceramic was characterized by the three- point bending strength test, thermal shock strength test and hertzian indentation strength test. The flexural strength and hertzian indentation strength of these porous ceramics at room temperature decrease with an increase in porosity. However, the flexural strength after thermal shock was significantly improved by increasing the temperature change. The oxidation behavior and thermal stability of porous SiAlCN ceramics were also explored by the mass change versus oxidation time and temperature. The phase evolution at different temperatures was also investigated by XRD analysis.M.S.
Department of Mechanical, Materials and Aerospace Engineering;
Engineering and Computer Science
Materials Science & Engr MSMSE
29
Rambacher, Robert William. "Pyridoimudazolium cationic dyes theory, synthesis, and sub-cellular localization /." Huntington, WV : [Marshall University Libraries], 2004. http://www.marshall.edu/etd/descript.asp?ref=163.
Повний текст джерелаАнотація:
Thesis (M.S.)--Marshall University, 2004.Title from document title page. Includes abstract. Document formatted into pages; contains viii, 79 p. including illustrations. Includes bibliographical references (p. 56).
30
Åsberg, Mikael. "Synthesis and Synchronization Support for Hierarchically Scheduled Real-Time Systems." Doctoral thesis, Mälardalens högskola, Akademin för innovation, design och teknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-23462.
Повний текст джерелаАнотація:
A piece of software, that we define as a software system, can consist of anything from a few lines of program code or the entire software stack in a vehicle. Software systems can be divided into smaller and partially independent parts called subsystems/partitions (we use the words partition and subsystem interchangeably). The non-functional isolation of subsystems, that appears when the software system is hierarchically divided, has great advantages when it comes to preventing fault propagation between subsystems. The hierarchical division, that we refer to as hierarchical scheduling, has other advantages as well. It facilitates re-usability and it makes timing analysis of software systems easier. Hierarchical scheduling has been shown to be a useful tool in counteracting the verification challenges that comes from the growing complexity in software. For example, the avionics-specification ARINC653 and the safety-critical operating systems seL4 and PikeOS safely divide resources for independent safety-critical applications by using hierarchical scheduling. Hierarchical scheduling can be implemented in many different ways, depending on what resource that is supposed to be shared among applications. The resource could be the CPU, memory, network etc. The work in this thesis is focused on the practical aspects of timing isolation among subsystems, i.e., sharing of the CPU resource. Hence, this work elaborates on how to adapt and extend the operating-system task-scheduler to support hierarchical scheduling. We have focused on both independent and semi-dependent subsystems. Independent subsystems only share general resources such as the CPU and memory. Semi-independent subsystems share not only the general resources, but also other logical resources that can only be accessed in a mutually exclusive way, i.e., by one subsystem at a time. An example of such a resource could be a shared memory-space, e.g., a database, a memory-mapped device etc. This thesis has two main parts related to hierarchical scheduling: scheduler synthesis, and synchronization. Scheduler synthesis is related to implementation and design strategies when adding support for hierarchical scheduling in an operating system. We have focused on various operating systems that were lacking the feature of hierarchical scheduling. The two most interesting operating systems that we worked on was Linux and seL4. These two operating systems represent two extremes, where Linux is more focused towards soft real-time systems and seL4 towards pure hard real-time (safety-critical) systems. Linux-based systems have in general less strict demands on correctness and more requirements on usability. Usability implies less installation efforts and less limitations in the usage of the available Linux functionality. The usability aspect is especially important for Linux systems since kernel updates occur much more frequently compared to any other operating system. Hence, extending/modifying the functionality of Linux must be done in a way that does not require any modifications to the kernel. seL4 on the other hand has strict requirements on safety, i.e., functional and non-functional correctness, but also performance efficiency. Guaranteeing correctness implies a potential loss of performance due to the added overhead that the verified software can bring. The correctness aspect includes strategies on how to verify hierarchical schedulers, but also how to minimize the scheduler overhead and achieve as good run-time performance as possible. Conclusively, there are many challenges when it comes to scheduler synthesis. There are requirements on performance, usability, correctness etc. The contribution in the synthesis part includes a scheduler framework called ExSched (External Scheduler). We have also contributed with a novel approach to verify hierarchical schedulers, and a code generator called TAtoC (Timed Automata to C) which contributes to the effective run-time performance of synthesized timed-automata models. The second part of this thesis, synchronization, is an important general aspect of hierarchically scheduled systems since the isolation of subsystems makes resource sharing among subsystems more challenging. We have advanced the state-of-the-art in this research area by introducing a new synchronization protocol called RRP (Rollback Resource Policy) that improves on the robustness and run-time performance compared to the existing protocols. We have also conducted a large scale experimental evaluation of all existing protocols that we have implemented in the widely used real-time operating system VxWorks.
31
Pop, Paul. "Analysis and synthesis of communication-intensive heterogeneous real-time systems /." Linköping : Univ, 2003. http://www.bibl.liu.se/liupubl/disp/disp2003/tek833s.pdf.
Повний текст джерела
32
Tams, A. C. "Modelling intonation of read aloud speaking styles for speech synthesis." Thesis, University of Essex, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269672.
Повний текст джерела
33
Chou, Pai Hsiang. "Control composition and synthesis of distributed real-time embedded systems /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/6895.
Повний текст джерела
34
TAVARES, Eduardo Antônio Guimarães. "Software Synthesis for Energy-Constrained Hard Real-Time Embedded Systems." Universidade Federal de Pernambuco, 2009. https://repositorio.ufpe.br/handle/123456789/1403.
Повний текст джерелаАнотація:
Made available in DSpace on 2014-06-12T15:49:47Z (GMT). No. of bitstreams: 1
license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)
Previous issue date: 2009A grande expansão do mercado de dispositivos digitais tem forçado empresas desenvolvedoras de sistemas embarcados em lidar com diversos desafios para prover sistemas complexos nesse nicho de mercado. Um dos desafios prominentes está relacionado ao consumo de energia, principalmente, devido aos seguintes fatores: (i) mobilidade; (ii) problemas ambientais; e (iii) o custo da energia. Como consequência, consideráveis esforços de pesquisa têm sido dedicados para a criação de técnicas voltadas para aumentar a economia de energia. Na última década, diversas técnicas foram desenvolvidas para reduzir o consumo de energia em sistemas embarcados. Muitos métodos lidam com gerenciamento dinâmico de energia (DPM), como, por exemplo, dynamic voltage scaling (DVS), cooperativamente com sistemas operacionais especializados, a fim de controlar o consumo de energia durante a execução do sistema. Entretanto, apesar da disponibilidade de muitos métodos de redução de consumo de energia, diversas questões estão em aberto, principalmente, no contexto de sistemas de tempo real crítico. Este trabalho propõe um método de síntese de software, o qual leva em consideração relação entre tarefas, overheads, restrições temporais e de energia. O método é composto por diversas atividades, as quais incluem: (i) medição; (ii) especificação; (iii) modelagem formal; (vi) escalonamento; e (v) geração de código. O método também é centrado no formalismo redes de Petri, o qual define uma base para geração precisa de escalas em tempo de projeto, adotando DVS para reduzir o consumo de energia. A partir de uma escala viável, um código customizado é gerado satisfazendo as restrições especificadas, e, dessa forma, garantindo previsibilidade em tempo de execução. Para lidar com a natureza estática das escalas geradas em tempo de projeto, um escalonador simples em tempo de execução é também proposto para melhorar o consumo de energia durante a execução do sistema. Diversos experimentos foram conduzidos, os quais demonstram a viabilidade da abordagem proposta para satisfazer restrições críticas de tempo e energia. Adicionalmente, um conjunto integrado de ferramentas foram desenvolvidas para automatizar algumas atividades do método de síntese de software proposto
35
Sil, Devika. "SYNTHESIS AND APPLICATIONS OF PLASMONIC NANOSTRUCTURES." Diss., Temple University Libraries, 2015. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/364016.
Повний текст джерелаАнотація:
ChemistryPh.D.
The localized surface plasmon resonance (LSPR), arising due to the collective oscillation of free electrons in metal nanoparticles, is a sensitive probe of the nanostructure and its surrounding dielectric medium. Synthetic strategies for developing surfactant free nanoparticles using ultrafast lasers providing direct access to the metallic surface that harvest the localized surface plasmons will be discussed first followed by the applications. It is well known that the hot carriers generated as a result of plasmonic excitation can participate and catalyze chemical reactions. One such reaction is the dissociation of hydrogen. By the virtue of plasmonic excitation, an inert metal like Au can become reactive enough to support the dissociation of hydrogen at room temperature, thereby making it possible to optically detect this explosive gas. The mechanism of sensing is still not well understood. However, a hypothesis is that the dissociation of hydrogen may lead to the formation of a metastable gold hydride with optical properties distinct from the initial Au nanostructures, causing a reversible increase in transmission and blue shift in LSPR. It will also be shown that by tracking the LSPR of bare Au nanoparticles grown on a substrate, the adsorption of halide ions on Au can be detected exclusively. The shift in LSPR frequency is attributed to changes in electron density rather than the morphology of the nanostructures, which is often the case.
Temple University--Theses
36
Oreifej, Rashad. "SYNTHESIS OF SELF-RESETTING STAGE LOGIC PIPELINES." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3572.
Повний текст джерелаАнотація:
As designers began to pack multi-million transistors onto a single chip, their reliance on a global clocking signal to orchestrate the operations of the chip has started to face almost insurmountable difficulties. As a result, designers started to explore clockless circuits to avoid the global clocking problem. Recently, self-resetting circuits implemented in dynamic logic families have been proposed as viable clockless alternatives. While these circuits can produce excellent performances, they display serious limitations in terms of area cost and power consumption. A middle-of-the-road alternative, which can provide a good performance and avoid the limitations seen in dynamic self-resetting circuits, would be to implement self-resetting behavior in static circuits. This alternative has been introduced recently as Self-Resetting Stage Logic and used to propose three types of clockless pipelines. Experimental studies show that these pipelines have the potential to produce high throughputs with a minimum area overhead if a suitable synthesis methodology is available. This thesis proposes a novel synthesis methodology to design and verify clockless pipelines implemented in SRSL by taking advantage of the maturity of current CAD tools. This methodology formulates the synthesis problem as a combinatorial analytical problem for which a run-time efficient exact solution is difficult to derive. Consequently, a two-phase algorithm is proposed to synthesize these pipelines from gate netlists subject to user-specified constraints. The first phase is a heuristic based on the as-soon-as-possible scheduling strategy in which each gate of the netlist is assigned to a single pipeline stage without violating the period constraint of each pipeline stage. On the other hand, the second phase consists of a heuristic, based on the Kernighan-Lin partitioning strategy, to minimize the number of nets crossing each pair of adjacent pipeline stages. The objective of this optimization is to reduce the number of latches separating pipeline stages since these latches tend to occupy large areas. Experiments conducted on a prototype of the synthesis algorithm reveal that these self-resetting stage logic pipelines can easily reach throughputs higher than 1 GHz. Furthermore, these experiments reveal that the area overhead needed to implement the self-resetting circuitry of these pipelines can be easily amortized over the area of the logic embedded in the pipeline stages. In the overall, the synthesis methods developed for SRSL produce low area overhead pipelines for wide and deep gate netlists while it tends to produce high throughput pipelines for wide and shallow gate netlists. This shows that these pipelines are mostly suitable for coarse-grain datapaths.M.S.Cp.E.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Computer Engineering
37
Edupuganti, Ramakrishna. "Asymmetric Synthesis of Homotropinone and Tropane Alkaloids using Enantiopure Sulfinimines and the Synthesis and Applications of Methanoprolines." Diss., Temple University Libraries, 2011. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/155171.
Повний текст джерелаАнотація:
ChemistryPh.D.
The development of new methodologies for the asymmetric synthesis of homotropinone and tropane alkaloids using enantiopure sulfinimines [RS(O)N=CR1R²] is the primary objective of this thesis. In one study a four-step intramolecular Mannich cyclization cascade reaction was devised for the asymmetric synthesis of substituted homotropinone alkaloids from enantiopure sulfinimine-derived N-sulfinyl ß-amino ketone ketals. These amino ketone ketal chiral building blocks were prepared in 67-71% yields and high dr (25-14:1) by addition of the Weinreb amide enolate of N-methoxy-Nmethylacetamide to masked oxo sulfinimines (N-sulfinyl imines). Treatment of these Weinreb amides with Grignard reagents gave the N-sulfinyl ß-amino ketone ketals in 93- 95% yields without epimerization. Heating the acyclic ß-amino ketone ketals with the buffer solution NH4OAc:HOAc resulted in a one-pot 4 step intramolecular Mannich cyclization cascade reaction to give substituted homotropinones including (–)- euphococcinine and (–)-adaline in 82-90% yields. In another study a sulfinimine-derived α,ß-unsaturated pyrrolidine nitrone was utilized in the development of a Lewis acid catalyzed [3+2] nitrone cycloaddition reaction for the asymmetric synthesis of the tropane alkaloid (+)-cocaine. The masked oxo sulfinimine was treated with an excess of the sodium enolate of methyl acetate to give N-sulfinyl ß-amino ester in 87% yield and high dr (97:3). Reduction of the ester to aldehyde followed by a Horner-Wadsworth-Emmons olefination reaction afforded the α,ß-unsaturated N-sulfinyl amino acetal. Hydrolysis of the unsaturated amino acetal gave a pyrrolidine, which was selectively oxidized to the pyrrolidine nitrone. The nitrone on heating with the Lewis acid Al(O-t-Bu)3 for 96 h underwent an intramolecular [3+2] cycloaddition to give a tricyclic isoxazolidine, which was transformed into (+)-cocaine in three steps 25% overall yield. This 9 step, 25% overall yield synthesis of (S)-(+)-cocaine from the masked oxo sulfinimine is the most efficient enantioselective route to cocaine from acyclic starting materials. This new methodology is adaptable to the preparation of various cocaine analogs including the first cocaine C-1 analogs. In other studies conformationally constrained novel pyrrolidine analogs (methanopyrrolidines) were synthesized stereoselectively to study the substituent (H, OH, or F) effect on amide conformational preferences. A nucleophilic displacement synthetic route was devised to prepare highly functionalized 5(6)-anti-substituted-methanopyrrolidines from N-benzyl-2-azabicyclo[2.1.1]hexylbromide(s) intermediates with the aid of neighboring group participation. These methanopyrrolidines were then transformed to constrained proline analogs (methanoprolines) to evaluate the impact of proline ring pucker on amide conformations. An α-methoxycarbonyl group was introduced in methanopyrrolidines by treating tert-butoxycarbonyl protected methanopyrrolidines with s-BuLi and quenching with various electrophiles such as CO2, DMF or ClCO2Me. Amide trans-cis conformational preferences (Ktrans/cis) of N-acetyl-methanopyrrolidines and N-acetyl-methanoprolines were determined in various solvents such as CDCl3 and D2O using NMR techniques, including NOE. The small trans amide preference for substituted fluoro- and hydroxy-methanopyrrolidines shows that it is the interaction of the !-methyl ester group and the amide moiety of the methanoprolines that plays a major role in determining amide conformational preferences. The gamma-substituent effect is primarily related to ring pucker and a resultant enhancement of the interaction between the amide carbonyl oxygen and ester carbonyl carbon. The results are relevant to the conformational stability of collagen and protein engineering.
Temple University--Theses
38
Rai, Prabin. "Design and Synthesis of Fluorescent Probes." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1375091914.
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39
Yildiz, Mursel. "User Directed View Synthesis On Omap Processors." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/12610682/index.pdf.
Повний текст джерелаАнотація:
In this thesis, real time image rendering for hand held devices is studied according to user&rsquos view point choice and using image frames with corresponding depth maps obtained from 2 different cameras, of which positions on coordinate system is known. User&rsquo
s view point choice is restricted to the area between right, and left cameras. Occlusion handling methods for image rendering systems is explored and discussed together with frame enhancement techniques. Median filtering is studied for multicolor image frames and post processing methods are discussed for image enhancement at the end of rendering algorithm. In this thesis, OMAP3530 microprocessor is used as the main processor which processes suggested rendering algorithm with occlusion handling and frame enhancement. proposed algorithms are implemented on DSP core and ARM cores of OMAP3530 separately and their performances are evaluated through experiments. Embedded Linux (Kernel-2.6.22) is run as the operating system for applications. Driver usage together with devices for Linux embedded operating system is explored and studied. 3 boards are used for the realization of proposed system. OMAP35x EVM board from Mistral Solutions Company is used for processor utilization, high resolution LCD utilization, system monitoring, user interface and communication purposes. Two daughter cards are designed for user view point determination. First daughter card handles communication process with EVM board and calculates view point according to input from second daughter card with single axis response GYRO sensor (ADIS16060). Spartan®
-3A DSP FPGA family is utilized in this system for view point determination. DSP slices that are hardly present inside gate arrays of this FPGA family are utilized and their performance is studied. Asynchronous memory interface, i2c bus interface, SPI interface are studied and implemented on FPGA.
40
Crews, Everett III. "Retroaldo-trapping reactions of [beta]-hydroxy-[alpha]-phenylsulfenyl cyclohexanone and decalone derivatives and the total synthesis of the California red scale sex pheromone." Diss., Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/27404.
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41
Sankur, Ocan. "Robustness in timed automata : analysis, synthesis, implementation." Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2013. http://tel.archives-ouvertes.fr/tel-00910333.
Повний текст джерелаАнотація:
Timed automata are a formalism to model, verify, and synthesize real-time systems. They have the advantage of having an abstract mathematical semantics, which allow formalizing and solving several verification and synthesis problems. However, timed automata are intended to design models, rather than completely describe real systems. Therefore, once the design phase is over, it remains to check whether the behavior of an actual implementation corresponds to that of the timed automaton model. An important step before implementing a system design is ensuring its robustness. This thesis considers a notion of robustness that asks whether the behavior of a given timed automaton is preserved, or can be made so, when it is subject to small perturbations. Several approaches are considered: Robustness analysis seeks to decide whether a given timed automaton tolerates perturbations, and in that case to compute the (maximum) amount of tolerated perturbations. In robust synthesis, a given system needs to be controlled by a law (or strategy) which tolerates perturbations upto some computable amount. In robust implementation, one seeks to automatically transform a given timed automaton model so that it tolerates perturbations by construction. Several perturbation models are considered, ranging from introducing error in time measures (guard enlargement), forbidding behaviors that are too close to boundaries (guard shrinking), and restricting the time domain to a discrete sampling. We also formalize robust synthesis problems as games, where the control law plays against the environment which can systematically perturb the chosen moves, by some bounded amount. These problems are studied on timed automata and their variants, namely, timed games, and weighted timed automata and games. Algorithms for the parameterized robustness analysis against guard enlargements, and guard shrinkings are presented. The robust synthesis problem is studied for two variants of the game semantics, for timed automata, games, and their weighted extensions. A software tool for robustness analysis against guard shrinkings is presented, and experimental results are discussed. The robust implementation problem is also studied in two different settings. In all algorithms, an upper bound on perturbations that the given timed automaton tolerates can be computed.
42
Kokkonda, Praveen. "TOTAL SYNTHESIS OF STRYCHNOS AND ASPIDOSPERMATAN ALKALOIDS." Diss., Temple University Libraries, 2017. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/435652.
Повний текст джерелаАнотація:
ChemistryPh.D.
The Strychnos class of indole alkaloids contain a pyrrolo[2,3-d]carbazole ABCE tetracyclic framework. The second-generation ABCE tetracycle approach was employed in the total synthesis of (±)-20-epi-lochneridine and progress toward total synthesis of (±)-alstolucine B. The second-generation approach featured Mitsunobu activation of the hydroxyethyl group in a gramine intermediate followed by intramolecular aza-Baylis-Hillman reaction. The substrate for hydroboration was redesigned to (±)-18-desmethyl akuammicine (1,1-disubstituted double bond), since the hydroboration of trisubstituted alkenes afforded tertiary alcohol via Markovnikov addition. The key steps were n-Bu3SnH mediated cyclization reaction to accomplish D-ring, tert-butyl hypochlorite indoline oxidation, and anti-Markovnikov hydroboration to introduce a primary alcohol. The total syntheses of Strychnos-Strychnos type bis-indole alkaloids (−)-leucoridine A and C were accomplished from the biomimetic dimerization of (−)-dihydrovalparicine. En route to (−)-dihydrovialparicine, known alkaloids (+)-geissoschizoline and (−)-dehydrogeissoschizoline were also prepared from commercially available N-tosyl indole 3-carboxaldehyde. Key steps consisted of an in situ dimerization of (−)-dihydrovalparicine from (−)-1, 2-dehydrogeissoschizoline with trifluoroacetic acid in the presence of 4 Å molecular sieves. Acid mediated ring-opening of the indolenine in (−)-leucoridine A to afford (−)-leucoridine C. DFT calculations were employed to elucidate the mechanism of dimerization, which suggested that a stepwise aza-Michael/spirocyclization sequence was preferred over the alternate hetero Diels-Alder cycloaddition reaction. A novel domino Michael/Mannich [4+2] annulation method was applied for concise total synthesis of Aspidospermatan alkaloids (+)-20-epi-condyfoline and progress toward the total synthesis of (+)-condyfoline. The additional key steps consisted of a LiHMDS mediated cyclization to form D-ring, dimethyl(methylthio)sulfonium tetrafluoroborate (DMTSF) mediated spirocyclization to form pentacyclic thioether and indoline oxidation with MnO2.
Temple University--Theses
43
Qiu, Shipeng. "SYNTHESIS, PROCESSING AND CHARACTERIZATION OF NANOCRYSTALLINE TITANIUM DIOXIDE." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3591.
Повний текст джерелаАнотація:
Titanium dioxide (TiO2), one of the basic ceramic materials, has found a variety of applications in industry and in our daily life. It has been shown that particle size reduction in this system, especially to nano regime, has the great potential to offer remarkable improvement in physical, mechanical, optical, biological and electrical properties. This thesis reports on the synthesis and characterization of the nanocrystalline TiO2 ceramic in details. The study selected a simple sol-gel synthesis process, which can be easily controlled and reproduced. Titanium tetraisopropoxide, isopropanol and deionized water were used as starting materials. By careful control of relative proportion of the precursor materials, the pH and peptization time, TiO2 nanopowder was obtained after calcination at 400oC. The powder was analyzed for its phases using X-ray powder diffraction (XRD) technique. Crystallite size, powder morphology and lattice fringes were determined using high-resolution transmission electron microscopy (HR-TEM). Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were used to study the thermal properties. As-synthesized powder was uniaxially compacted and sintered at elevated temperature of 1100-1600oC to investigate the effects of sintering on nano powder particles, densification behavior, phase evolution and mechanical properties. Microstructure evolution as a function of sintering temperature was studied by scanning electron microscopy (SEM). The results showed that 400oC was an optimum calcination temperature for the as-synthesized TiO2 powder. It was high enough to achieve crystallization, and at the same time, helped minimize the thermal growth of the crystallites and maintain nanoscale features in the calcined powder. After calcination at 400oC (3 h), XRD results showed that the synthesized nano-TiO2 powder was mainly in single anatase phase. Crystallite size was first calculated through XRD, then confirmed by HR-TEM, and found to be around 5~10 nm. The lattice parameters of the nano-TiO2 powder corresponding to this calcination temperature were calculated as a=b=0.3853 nm, c=0.9581 nm, α=β=γ=90o through a Rietveld refinement technique, which were quite reasonable when comparing with the literature values. Considerable amount of rutile phase had already formed at 600oC, and the phase transformation from anatase to rutile fully completed at 800oC. The above rutilization process was clearly recorded from XRD data, and was in good corresponding to the DSC-TGA result, in which the broad exothermic peak continued until around 800oC. Results of the sintered TiO2 ceramics (1100oC-1600oC) showed that, the densification process continued with the increase in sintering temperature and the highest geometric bulk sintered density of 3.75 g/cm3 was achieved at 1600oC. The apparent porosity significantly decreased from 18.5% to 7.0% in this temperature range, the trend of which can be also clearly observed in SEM micrographs. The hardness of the TiO2 ceramics increased with the increase in sintering temperature and the maximum hardness of 471.8±30.3 HV was obtained at 1600oC. Compression strength increased until 1500oC and the maximum value of 364.1±10.7 MPa was achieved; after which a gradual decrease was observed. While sintering at ambient atmosphere in the temperature range of 1100oC-1600oC helped to improve the densification, the grain size also increased. As a result, though the sintered density at 1600oC was the highest, large and irregular-shaped grains formed at this temperature would lead to the decrease in the compression strength.M.S.M.S.E.
Department of Mechanical, Materials and Aerospace Engineering;
Engineering and Computer Science
Materials Science and Engineering
44
Rhoden, Stephen. "SYNTHESIS OF NOVEL AZIRIDINE DERIVATIVES OF PODOCARPIC ACID." Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3569.
Повний текст джерелаАнотація:
Podocarpic acid (a diterpenoid resin acid extracted from the Podocarpacea specie of plants) has shown cytotoxicity against carcinoma of the nasopharynx. Since this discovery has been made, research has been performed in order to alter the structure of the resin acid so as to increase the anticancer activity. The carboxylic acid and phenol functional groups, which are present in podocarpic acid, make it possible to synthesize new derivatives selectively at the C-15, C-13, and C-7 positions as well as by substitution of the phenol hydroxyl group. Thus numerous derivatives can be prepared, in high yield, for the purpose of investigating their potential, as new drug leads for the treatment of cancer. In this study, Doyle's catalyst (Dirhodium tetrakis caprolactamate) was used to form a novel derivative in high yield (85%) which contained a 3-membered aziridine ring at the C-6 and C-7 position. The main thrust of this research involved the formation a series of novel derivatives of the aziridine compound by utilizing phenol and m-chlorophenol as nucleophiles to open the aziridine ring. These novel compounds will now be sent to the National Institute of Health (NIH) for bioassay against 60 human cancer cell lines.M.S.
Department of Chemistry
Sciences
Industrial Chemistry MS
45
Lawal, Najeem. "Memory Synthesis for FPGA Implementation of Real-Time Video Processing Systems." Doctoral thesis, Mittuniversitetet, Institutionen för informationsteknologi och medier, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-7697.
Повний текст джерелаАнотація:
In this thesis, both a method and a tool to enable efficient memory synthesis for real-time video processing systems on field programmable logic array are presented. In real-time video processing system (RTVPS), a set of operations are repetitively performed on every image frame in a video stream. These operations are usually computationally intensive and, depending on the video resolution, can also be very data transfer dominated. These operations, which often require data from several consecutive frames and many rows of data within each frame, must be performed accurately and under real-time constraints as the results greatly affect the accuracy of application. Application domains of these systems include machine vision, object recognition and tracking, visual enhancement and surveillance. Developments in field programmable gate arrays (FPGAs) have been the motivation for choosing them as the platform for implementing RTVPS. Essential logic resources required in RTVPS operations are currently available and are optimized and embedded in modern FPGAs. One such resource is the embedded memory used for data buffering during real-time video processing. Each data buffer corresponds to a row of pixels in a video frame, which is allocated using a synthesis tool that performs the mapping of buffers to embedded memories. This approach has been investigated and proven to be inefficient. An efficient alternative employing resource sharing and allocation width pipelining will be discussed in this thesis. A method for the optimised use of these embedded memories and, additionally, a tool supporting automatic generation of hardware descriptions language (HDL) modules for the synthesis of the memories according to the developed method are the main focus of this thesis. This method consists of the memory architecture, allocation and addressing. The central objective of this method is the optimised use of embedded memories in the process of buffering data on-chip for an RVTPS operation. The developed software tool is an environment for generating HDL codes implementing the memory sub-components. The tool integrates with the Interface and Memory Modelling (IMEM) tools in such a way that the IMEM’s output - the memory requirements of a RTVPS - is imported and processed in order to generate the HDL codes. IMEM is based on the philosophy that the memory requirements of an RTVPS can be modelled and synthesized separately from the development of the core RTVPS algorithm thus freeing the designer to focus on the development of the algorithm while relying on IMEM for the implementation of memory sub-components.Electronics design division
Sensible Things that Communicate
46
Lawal, Najeem. "Memory Synthesis for FPGA Implementation of Real-Time Video Processing Systems." Licentiate thesis, Mid Sweden University, Department of Information Technology and Media, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-7696.
Повний текст джерелаАнотація:
In this thesis, both a method and a tool to enable efficient memory synthesis for real-time video processing systems on field programmable logic array are presented. In real-time video processing system (RTVPS), a set of operations are repetitively performed on every image frame in a video stream. These operations are usually computationally intensive and, depending on the video resolution, can also be very data transfer dominated. These operations, which often require data from several consecutive frames and many rows of data within each frame, must be performed accurately and under real-time constraints as the results greatly affect the accuracy of application. Application domains of these systems include object recognition, object tracking and surveillance.
Developments in field programmable gate array (FPGA) have been the motivation for choosing them as the platform for implementing RTVPS. Essential logic resources required in RTVPS operation are currently available optimized and embedded in modern FPGAs. One such resource is the embedded memory used for data buffering during real-time video processing. Each data buffer corresponds to a row of pixels in a video frame, which is allocated using a synthesis tool that performs the mapping of buffers to embedded memories. This approach has been investigated and proven to be inefficient. An efficient alternative employing resource sharing and allocation width pipelining will be discussed in this thesis.
A method for the optimal use of these embedded memories and, additionally, a tool supporting automatic generation of hardware descriptions language (HDL) codes for the synthesis of the memories according to the developed method are the main focus of this thesis. This method consists of the memory architecture, allocation and addressing. The central objective of this method is the optimal use of embedded memories in the process of buffering data on-chip for an RVTPS operation. The developed software tool is an environment for generating HDL codes implementing the memory sub-components.
The tool integrates with the Interface and Memory Modelling (IMEM) tools in such a way that the IMEM’s output - the memory requirements of a RTVPS - is imported and processed in order to generate the HDL codes. IMEM is based on the philosophy that the memory requirements of an RTVPS can be modelled and synthesized separately from the development of the core RTVPS algorithm thus freeing the designer to focus on the development of the algorithm while relying on IMEM for the implementation of memory sub-components.
Sensible Things That Communicate
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Keates, Adam. "The design and synthesis of near infra-red absorbing inorganic pigments." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/380915/.
Повний текст джерелаАнотація:
Materials which exhibit strong absorption in the Near Infra-Red (NIR) region have applications as laser-marking pigments, IR filters in photovoltaics and CCD detectors, medical imaging devices and absorbing coatings in solar thermal collectors. New NIR absorbing materials based on iron (II) and copper (II) frameworks have been designed using knowledge of predicted d-energy levels and associated transitions. Materials from this class have been synthesised and characterised in terms of structure and optical properties A family of 13 iron phosphates and fluorophosphates have been obtained using hydrofluorothermal routes and characterised using single crystal X-ray diffraction. These materials show a variety of structural elements with one-, two- and three-dimensional connectivity. For example RbFe3(PO3F)2(PO2(OH)2)F2 has a framework structure consisting of face-sharing FeO4F2 octahedra linked by PO3F tetrahedra, which are orientated such that the fluoride are terminal and line inter-framework space. This includes the first example of a hydrothermally synthesised iron chlorofluorophosphate, (NH4)2Fe(II)Fe(III)(PO3F)2FCl2, which contains sheets of FeIIO2Cl4 octahedra linked together by edge-sharing chloride and chains of FeIIIO4F2 octahedra trans linked by μ2-bridging fluoride. UV/Vis/NIR spectra have been collected for 49 compounds and correlations between structure and NIR absorbing properties have been derived. A trend in ligand fields across the series SiO4, PO4 SO4 determined SiO4 showing the weakest ligand field making compounds with this ligand most suitable for NIR absorbing applications. Eight of the most promising materials have been tested for their laser-marking properties using a Nd:YAG laser at Merck, Darmstadt. The effect of particles size on the optical and laser-marking properties has been investigated using K2FeP2O7 as an example. The decrease in particle size caused a red-shift in the absorbance maxima, and produced a well dispersed pigment within the test polymer matrix. Out of these eight compounds, Cu2PO4OH and Cu4PO4O exhibited laser-marking properties comparable to other commercial Merck NIR absorbing pigments.
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Song, Zhuoyue. "Robust analysis and synthesis for uncertain negative-imaginary systems." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/robust-analysis-and-synthesis-for-uncertain-negativeimaginary-systems(9de4af43-983c-42a2-bafe-062970a738be).html.
Повний текст джерелаАнотація:
Negative-imaginary systems are broadly speaking stable and square (equal number of inputs and outputs) systems whose Nyquist plot lies underneath (never touches for strictly negative-imaginary systems) the real axis when the frequency varies in the open interval 0 to ∞. This class of systems appear quite often in engineering applications, for example, in lightly damped flexible structures with collocated position sensors and force actuators, multi-link robots, DC machines, active filters, etc. In this thesis, robustness analysis and controller synthesis methods for uncertain negative-imaginary systems are explored. Two new reformulation techniques are proposed that facilitate both the robustness analysis and controller synthesis for uncertain negative-imaginary systems. These reformulations are based on the transformation from negative-imaginary systems to a bounded-real framework via the positive-real property. In the presence of strictly negative-imaginary uncertainty, the robust stabilization problem is posed in an equivalent H∞ control framework; similarly, a negative-imaginary robust performance analysis problem is cast into an equivalent μ-framework. The latter framework also allows robust stability analysis when the perturbations are a mixture of bounded-real and negative-imaginary uncertainties. The proposed two techniques pave the way for existing H∞ control and μ theory to be applied to robustness analysis and controller synthesis for negative-imaginary systems. In addition, a static state-feedback synthesis method is proposed to achieve robust stability of a system in the presence of strictly negative-imaginary uncertainties. The method is developed in the LMI framework, which can be solved efficiently using convex optimization techniques. The controller synthesis method is based on the negative-imaginary stability theorem: a positive feedback interconnection of two negative-imaginary systems is internally stable if and only if the DC loop gain is contractive and at least one of the systems in the interconnected loop is strictly negative-imaginary. Also, in order to handle non-strict negative-imaginary uncertainties, a strongly strictly negative-imaginary lemma is proposed that helps to ensure the strictly negative-imaginary property of the nominal closed-loop system for robustness. To this end, a state-space characterization for strictly negative-imaginary property is given for non-minimal systems where the conditions are convex and hence numerically attractive. The results in this thesis hence facilitate both the robustness analysis and controller synthesis for negative-imaginary systems that quite often arise in practical scenarios. In addition, they can be applied to quantify the worse-case performance for this class of systems. Therefore, the proposed results have important implications in controller synthesis for uncertain negative-imaginary systems that achieve not only robust stabilization but also robust performance.
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Haft, Marcel. "Synthese intermetallischer Nanostrukturen in Kohlenstoffnanoröhren." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-222909.
Повний текст джерелаАнотація:
Kohlenstoffnanoröhren als eigenständige Modifikation des Kohlenstoffs sind zylindrische, aus mehreren Lagen Kohlenstoff aufgebaute Röhren, die über einen Hohlraum im Inneren verfügen. Bereits kurze Zeit nach ihrer Entdeckung, kam die Idee auf, Substanzen in diesen Hohlraum zu füllen. Durch den Einbau von Katalysatormaterial während der Synthese, ist bereits eine Vielzahl von Elementen als Füllmaterial zugänglich. Um jedoch nicht auf Elemente limitiert zu sein, die als Katalysator für die CNT-Synthese dienen, ist es möglich eine postsynthetische Füllung durchzuführen. Hier werden ungefüllte CNT geöffnet und anschließend, unter Ausnutzung der Kapillarkräfte, gefüllt.
In der vorliegenden Arbeit wurden zunächst verschiedene Methoden zur Füllung untersucht. Neben lösemittelbasierten Methoden wurde mit Salzschmelzen, durch Gasphasentransport und durch Füllung mit einer kovalenten Präkursorverbindung gefüllt. Da metallische Partikel das Ziel waren, folgte im Anschluss an die Füllung mit Salzen, Salzlösungen, oder anderen Präkursoren jeweils eine Reduktion mit Wasserstoffgas bei erhöhten Temperaturen. Die Ergebnisse der Füllung wurden umfassend mittels Elektronenmikroskopie untersucht. Füllungsgrade wurden mittels Thermogravimetrie bestimmt. So konnten für zahlreiche Elemente eine geeignete Methode zur Füllung mit metallischen Partikeln entwickelt werden.
Im Falle der Füllung mit Zinn konnte zudem gezeigt werden, dass ein Zusammenhang zwischen der Dauer der Füllreaktion und dem Anteil an drahtartigen Nanostrukturen in den CNT, sowie ein Zusammenhang zwischen der eingesetzten Lösungskonzentration und dem Füllungsgrad besteht. Im weiteren Verlauf der Arbeit wurde die Synthese von intermetallischen Partikeln in CNT untersucht. Hierbei dienten die Systeme Nickel-Zinn und Cobalt-Zinn, die als vielversprechende Materialien im Einsatz als Anodenmaterial in Lithium-Ionen-Akkumulatoren diskutiert werden, als Modellsysteme.
Zunächst wurde gezeigt, dass es nicht möglich ist, aus einem Gemisch des Zinnsalzes und des jeweiligen anderen Salzes erfolgreich intermetallische Partikel herzustellen. Mittels Pulverröntgendiffraktometrie (XRD) und energiedispersiver Röntgenspektroskopie (EDX) konnte gezeigt werden, dass lediglich Zinnpartikel in den CNT vorhanden waren.
Schließlich konnte mit dem Verfahren der sequentiellen Füllung eine erfolgreiche Synthese intermetallischer Nanostrukturen bewerkstelligt werden. Hierbei wird die CNT zuerst mit einer Lösung von Zinnchlorid
gefüllt und schließlich reduziert. Anschließend erfolgt eine weitere Füllung mit einem Nickel- bzw. Cobaltsalz und einer nachfolgenden Reduktion. Während dieser zweiten Reduktion erfolgt die Bildung der intermetallischen Nanostrukturen in den CNT. Mittels XRD konnte gezeigt werden, dass tatsächlich intermetallische Strukturen in der Probe enthalten sind und dass man zudem durch das Verhältnis der beiden eingesetzten Elemente (Zinn zu Nickel bzw. Cobalt) Einfluss auf die vorherrschende intermetallische Verbindung nehmen kann. Durch EDX-Linienscans und Elementkarten, die am Transmissionselektronenmikroskop angefertigt wurden, konnte nachgewiesen werden, dass einzelne, in den CNT befindliche Partikel, tatsächlich aus den beiden Elementen Zinn und Nickel bzw. Cobalt bestehen und somit intermetallisch sind.
Ein erster Test des erhaltenen Materials aus CNT und intermetallischen Nickel-ZinnVerbindungen als Anodenmaterial konnte bereits durchgeführt werden. Die gemessene Kapazität lag bereits im Bereich von Graphit, welches üblicherweise als Anodenmaterial verwendet wird, könnte jedoch durch Erhöhung des Anteils der intermetallischen Verbindung noch weiter gesteigert werden.
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Lundmark, Lukas. "Synthetic Meta-Learning: : Learning to learn real-world tasks with synthetic data." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264919.
Повний текст джерелаАнотація:
Meta-learning is an approach to machine learning that teaches models how to learn new tasks with only a handful of examples. However, meta-learning requires a large labeled dataset during its initial meta-learning phase, which restricts what domains meta-learning can be used in. This thesis investigates if this labeled dataset can be replaced with a synthetic dataset without a loss in performance. The approach has been tested on the task of military vehicle classification. The results show that for few-shot classification tasks, models trained with synthetic data can come close to the performance of models trained with real-world data. The results also show that adjustments to the data-generation process, such as light randomization, can have a significant effect on performance, suggesting that fine-tuning to the generation process could further improve performance.Metainlärning är en metodik inom maskininlärning som gör det möjligt att lära en modell nya uppgifter med endast en handfull mängd träningsexempel. Metainlärning kräver dock en stor mängd träningsdata under själva metaträningsfasen, vilket begränsar de domäner där metodiken kan användas. Detta examensarbete utreder huruvida syntetisk bilddata, som genererats med hjälp av en simulator, kan ersätta verklig bilddata under metainlärningsfasen. Metoden har utvärderats på militär fordonsklassificering. Resultaten visar att för bildklassificering med 1–10 träningsexempel per klass kan en modell metainlärd med syntetisk data närma sig prestandan hos en modell metainlärd med riktig data. Resultaten visar även att små ändringar i genereringsprocessen, exempelvis graden av slumpmässigt ljus, har en stor inverkan på den slutgiltiga prestandan, vilket ger hopp om att ytterligare finjustering av genereringsprocessen kan resultera i ännu fler prestandaförbättringar.