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France, Scott. "Biocatalytic imine reduction and reductive amination." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/biocatalytic-imine-reduction-and-reductive-amination(61ad6339-617a-425e-9063-1a2a57c8540f).html.
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Chiral amine motifs are found in many bioactive compounds and therefore strategies for their direct asymmetric synthesis are of great interest. Alongside traditional chemical methods, biocatalysis serves as an important tool for the formation of these compounds that can confer the benefits of sustainable catalyst supply and mild reaction conditions. This thesis describes the application of imine reductase (IRED) biocatalysts for the asymmetric reduction of pre-formed imines and the reductive amination of carbonyl compounds to produce chiral amines. These enzymes are relatively recent additions to the toolbox of biocatalysts for chiral amine synthesis and therefore their scope and application is still very much being explored. The research carried out as part of this PhD is presented as a series of manuscripts that have either been published or are planned for submission to peer-reviewed journals. The choice of presenting this thesis in journal format was made because a considerable body of the candidate's PhD research has been published, with the rest planned for publication in the near future. Furthermore, the compiled review articles and research papers lend themselves to a clear thesis narrative and, combined, have taken considerable time and effort to prepare, equal to that of a traditional thesis format. The contents are organised as follows: Chapter 1: an introduction to biocatalysis and its impact on sustainable chemical manufacturing; Chapter 2: a review assessing the current state of the art in imine reductase biocatalysts; Chapter 3: a perspective on the design and implementation of biocatalytic cascades; Chapter 4: a research article on the application of IREDs in a biocatalytic cascade for the synthesis of chiral piperidine and pyrrolidine frameworks; Chapter 5: aims of the PhD project; Chapter 6: a research article on the discovery and investigation of a reductive aminase (RedAm) found within the IRED family; Chapter 7: a research article on the screening of a diverse set of novel IREDs for their ability to facilitate reductive amination; Chapter 8: a research article on the synthesis of complex bulky dibenz[c,e]azepine compounds using IRED and transaminase biocatalysts; Chapter 9: a summary and outlook; Chapter 10: manuscript supporting information further detailing experimental work; Appendix: list of other publications resulting from this doctoral research.
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Ju, Xiumin. "Reductive Dehalogenation of Gas-phase Trichloroethylene using Heterogeneous Catalytic and Electrochemical Methods." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1366%5F1%5Fm.pdf&type=application/pdf.
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Baldiwala, Aliakbar. "Dimensionality Reduction for Commercial Vehicle Fleet Monitoring." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38330.
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A variety of new features have been added in the present-day vehicles like a pre-crash warning, the vehicle to vehicle communication, semi-autonomous driving systems, telematics, drive by wire. They demand very high bandwidth from in-vehicle networks. Various electronic control units present inside the automotive transmit useful information via automotive multiplexing. Automotive multiplexing allows sharing information among various intelligent modules inside an automotive electronic system. Optimum functionality is achieved by transmitting this data in real time. The high bandwidth and high-speed requirement can be achieved either by using multiple buses or by implementing higher bandwidth. But, by doing so the cost of the network and the complexity of the wiring in the vehicle increases.
Another option is to implement higher layer protocol which can reduce the amount of data transferred by using data reduction (DR) techniques, thus reducing the bandwidth usage. The implementation cost is minimal as only the changes are required in the software and not in hardware. In our work, we present a new data reduction algorithm termed as “Comprehensive Data Reduction (CDR)” algorithm. The proposed algorithm is used for minimization of the bus utilization of CAN bus for a future vehicle. The reduction in the busload was efficiently made by compressing the parameters; thus, more number of messages and lower priority messages can be efficiently sent on the CAN bus.
The proposed work also presents a performance analysis of proposed algorithm with the boundary of fifteen compression algorithm, and Compression area selection algorithms (Existing Data Reduction Algorithm). The results of the analysis show that proposed CDR algorithm provides better data reduction compared to earlier proposed algorithms. The promising results were obtained in terms of reduction in bus utilization, compression efficiency, and percent peak load of CAN bus. This Reduction in the bus utilization permits to utilize a larger number of network nodes (ECU’s) in the existing system without increasing the overall cost of the system. The proposed algorithm has been developed for automotive environment, but it can also be utilized in any applications where extensive information transmission among various control units is carried out via a multiplexing bus.
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Levin, Elizabeth Morris. "Effective litter reduction." Instructions for remote access. Click here to access this electronic resource. Access available to Kutztown University faculty, staff, and students only, 2006. http://www.kutztown.edu/library/services/remote_access.asp.
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Thesis (M.A. )--Kutztown University of Pennsylvania, 2006.Source: Masters Abstracts International, Volume: 45-06, page: 2924. Typescript. Abstract precedes thesis as 2 leaves (iii-iv). Includes bibliographical references (leaves 99-102).
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Van, Horn R. Brooks III. "Procedural Reduction Maps." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14484.
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Procedural textures and image textures are commonplace in graphics today, finding uses in such places as animated movies and video games. Unlike image texture maps, procedural textures typically suffer from minification aliasing. I present a method that, given a procedural texture on a surface, automatically creates an anti-aliased version of the procedural texture. The new procedural texture maintains the original textures details, but reduces minification aliasing artifacts. This new algorithm creates an image pyramid similar to MIP-Maps to represent the texture. Whereas a MIP-Map stores per-texel color, however, my texture hierarchy stores weighted sums of reflectance functions, allowing a wider-range of effects to be anti-aliased. The stored reflectance functions are automatically selected based on an analysis of the different functions found over the surface. When the texture is viewed at close range, the original texture is used, but as the texture footprint grows, the algorithm gradually replaces the textures result with an anti-aliased one. This results in faster development time for writing procedural textures as well as higher visual fidelity and faster rendering. With the optional addition of authoring guidelines, the analysis phase can be sped up by as much as two orders of magnitude.
Furthermore, I developed a method for handling pre-filtered integration of reflectance functions to anti-alias specular highlights. The normal-centric BRDF (NBRDF) allows for fast evaluation over a range of normals appearing on the surface of an object. The NBRDF is easy to implement on the GPU for real-time results and can be combined with procedural reduction maps for real-time procedural texture minification anti-aliasing.
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Chang, Jing. "Resistant dimension reduction /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1212784201&sid=10&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Power, Christopher. "Probabilistic symmetry reduction." Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3493/.
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Model checking is a technique used for the formal verification of concurrent systems. A major hindrance to model checking is the so-called state space explosion problem where the number of states in a model grows exponentially as variables are added. This means even trivial systems can require millions of states to define and are often too large to feasibly verify. Fortunately, models often exhibit underlying replication which can be exploited to aid in verification. Exploiting this replication is known as symmetry reduction and has yielded considerable success in non probabilistic verification. The main contribution of this thesis is to show how symmetry reduction techniques can be applied to explicit state probabilistic model checking. In probabilistic model checking the need for such techniques is particularly acute since it requires not only an exhaustive state-space exploration, but also a numerical solution phase to compute probabilities or other quantitative values. The approach we take enables the automated detection of arbitrary data and component symmetries from a probabilistic specification. We define new techniques to exploit the identified symmetry and provide efficient generation of the quotient model. We prove the correctness of our approach, and demonstrate its viability by implementing a tool to apply symmetry reduction to an explicit state model checker.
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Ariu, Kaito. "Online Dimensionality Reduction." Licentiate thesis, KTH, Reglerteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-290791.
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In this thesis, we investigate online dimensionality reduction methods, wherethe algorithms learn by sequentially acquiring data. We focus on two specificalgorithm design problems in (i) recommender systems and (ii) heterogeneousclustering from binary user feedback. (i) For recommender systems, we consider a system consisting of m users and n items. In each round, a user,selected uniformly at random, arrives to the system and requests a recommendation. The algorithm observes the user id and recommends an itemfrom the item set. A notable restriction here is that the same item cannotbe recommended to the same user more than once, a constraint referred toas a no-repetition constraint. We study this problem as a variant of themulti-armed bandit problem and analyze regret with the various structurespertaining to items and users. We devise fundamental limits of regret andalgorithms that can achieve the limits order-wise. The analysis explicitlyhighlights the importance of each component of regret. For example, we candistinguish the regret due to the no-repetition constraint, that generated tolearn the statistics of user’s preference for an item, and that generated tolearn the low-dimensional space of the users and items were shown. (ii) Inthe clustering with binary feedback problem, the objective is to classify itemssolely based on limited user feedback. More precisely, users are just askedsimple questions with binary answers. A notable difficulty stems from theheterogeneity in the difficulty in classifying the various items (some itemsrequire more feedback to be classified than others). For this problem, wederive fundamental limits of the cluster recovery rates for both offline andonline algorithms. For the offline setting, we devise a simple algorithm thatachieves the limit order-wise. For the online setting, we propose an algorithm inspired by the lower bound. For both of the problems, we evaluatethe proposed algorithms by inspecting their theoretical guarantees and usingnumerical experiments performed on the synthetic and non-synthetic dataset.Denna avhandling studerar algoritmer för datareduktion som lär sig från sekventiellt inhämtad data. Vi fokuserar speciellt på frågeställningar som uppkommer i utvecklingen av rekommendationssystem och i identifieringen av heterogena grupper av användare från data. För rekommendationssystem betraktar vi ett system med m användare och n objekt. I varje runda observerar algoritmen en slumpmässigt vald användare och rekommenderar ett objekt. En viktig begränsning i vår problemformuleringar att rekommendationer inte får upprepas: samma objekt inte kan rekommenderas till samma användartermer än en gång. Vi betraktar problemet som en variant av det flerarmadebanditproblemet och analyserar systemprestanda i termer av "ånger” under olika antaganden.Vi härleder fundamentala gränser för ånger och föreslår algoritmer som är (ordningsmässigt) optimala. En intressant komponent av vår analys är att vi lyckas att karaktärisera hur vart och ett av våra antaganden påverkar systemprestandan. T.ex. kan vi kvantifiera prestandaförlusten i ånger på grund av att rekommendationer inte får upprepas, på grund avatt vi måste lära oss statistiken för vilka objekt en användare är intresserade av, och för kostnaden för att lära sig den lågdimensionella rymden för användare och objekt. För problemet med hur man bäst identifierar grupper av användare härleder vi fundamentala gränser för hur snabbt det går att identifiera kluster. Vi gör detta för algoritmer som har samtidig tillgång till all data och för algoritmer som måste lära sig genom sekventiell inhämtning av data. Med tillgång till all data kan vår algoritm uppnå den optimala prestandan ordningsmässigt. När data måste inhämtas sekventiellt föreslår vi en algoritm som är inspirerad av den nedre gränsen på vad som kan uppnås. För båda problemen utvärderar vi de föreslagna algoritmerna numeriskt och jämför den praktiska prestandan med de teoretiska garantierna.
QC 20210223
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Brooks, Billy. "Harm Reduction Panel." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/etsu-works/3182.
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LEGRAMANTI, SIRIO. "Bayesian dimensionality reduction." Doctoral thesis, Università Bocconi, 2021. http://hdl.handle.net/11565/4035711.
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No abstract availableWe are currently witnessing an explosion in the amount of available data. Such growth involves not only the number of data points but also their dimensionality. This poses new challenges to statistical modeling and computations, thus making dimensionality reduction more central than ever. In the present thesis, we provide methodological, computational and theoretical advancements in Bayesian dimensionality reduction via novel structured priors. Namely, we develop a new increasing shrinkage prior and illustrate how it can be employed to discard redundant dimensions in Gaussian factor models. In order to make it usable for larger datasets, we also investigate variational methods for posterior inference under this proposed prior. Beyond traditional models and parameter spaces, we also provide a different take on dimensionality reduction, focusing on community detection in networks. For this purpose, we define a general class of Bayesian nonparametric priors that encompasses existing stochastic block models as special cases and includes promising unexplored options. Our Bayesian approach allows for a natural incorporation of node attributes and facilitates uncertainty quantification as well as model selection.
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Fruth, Florian. "Reduction of Aerodynamic Forcing inTransonic Turbomachinery : Numerical Studies on Forcing Reduction Techniques." Doctoral thesis, KTH, Kraft- och värmeteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-127967.
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Due to more and more aggressive designs in turbomachinery, assuring the structural integrity of its components has become challenging. Also influenced by this trend is blade design, where lighter and slimmer blades, in combination with higher loading, lead to an increased risk of failure, e.g. in the form of blade vibration. Methods have been proposed to reduce vibration amplitudes for subsonic engines, but cannot directly be applied to transonic regimes due to the additional physical phenomena involved. Therefore the present work investigates numerically the influence of two methods for reducing blade vibration amplitudes in transonic turbomachines, namely varying the blade count ratio and clocking. As it is known that clocking affects the efficiency, the concurrent effects on vibration amplitudes and efficiency are analyzed and discussed in detail. For the computational investigations, the proprietary Fortran-based non-linear, viscous 3D-CFD solver VolSol is applied on two transonic compressor cases and one transonic turbine case. In order to reduce calculation time and to generate the different blade count ratios a scaling technique is applied. The first and main part of this work focuses on the influence of the reduction techniques on aerodynamic forcing. Both the change in blade count ratio and clocking position are found to have significant potential for reducing aerodynamic force amplitudes. Manipulation of the phasing of excitation sources is found herein to be a major contributor to the amplitude variation. The lowest stimulus results are achieved for de-phased excitation sources and results in multiple blade force peaks per blade passing. In the case of blade count ratio variation it was found that blockage for high blade count ratios and the change in potential field size have significant impacts on the blade forcing. For the clocking investigation, three additional operating points and blade count ratios are analyzed and prove to have an impact on the force reduction achievable by clocking. The second part of the work evaluates the influence of clocking on the efficiency of a transonic compressor. It is found that the efficiency can be increased, but the magnitude of the change and the optimal wake impingement location depend on the operating point. Moreover it is shown that optimal efficiency and aerodynamic forcing settings are not directly related. In order to approximate the range of changes of both parameters, an ellipse approximation is suggested.QC 20130911
TURBOPOWER
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Siriwatcharapiboon, Wilai. "The electrochemistry of metal nanoparticles for oxygen reduction and nitrate/nitrite reduction." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4475/.
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This research has scientific aims focused on two important electrochemical reactions: oxygen reduction and nitrate/nitrite reduction. A series of rhodium (Rh) deposited on gold nanorods (Au NRs) and gold nanoparticles (Au NPs) were synthesised by wet chemical reduction. The scanning transmission electron microscopy (STEM) showed that Rh has a preferential deposition and epitaxial growth at the end of Au NRs. Cyclic voltammetry and rotating disc electrode (RDE) measurements were performed to study the oxygen reduction at these Au:Rh/C catalysts. Pyrolysed cobalt triethylenetetraamine on a carbon substrate (Co/TET A/C) was employed to produce H20 2 from the ORR. The results from the rotating ring disc electrode (RRDE) reveal that the heat treatment influences the H20 2 selectivity. The Co/TETA/C heated at 1000 oc yields the highest H20 2 selectivity while the Co/TETA/C heated at 700 oc yields the lowest H20 2 selectivity. Rh/C, Au:Rh/C nanoparticles and Sn modified Rh/C nanoparticles were employed for nitrate/nitrite reduction in acidic media. Results from on-line electrochemical mass spectrometry (OLEMS) reveal that the modified electrode generates N2 from further reduction of the nitrous oxide (N20) intermediate. Ion chromatography (IC) shows that ammonium is the main product at Rh/C. Hydroxylamine can also be detected after Sn modification on Rh/C.
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Wessels, Charlotte Elize. "Reduction of selenium by Pseudomonas Stutzeri NT-l; Growth reduction and kinetics." Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/62802.
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Bioremediation of seleniferous water is gaining more momentum, especially when it comes to bacterial reduction of the selenium oxyanions. More and more bacterial strains that are able to reduce selenium are being isolated. These bacteria need to be studied further to determine whether they are suited for industrial application. In this study, the reduction of Se(VI) to Se(0) by Pseudomonas stutzeri NT-I was examined using batch experiments with the bacteria suspended in MSM. For the determination of the optimum conditions for the growth of the bacteria, the linearized rate during the exponential phase for different conditions were compared. A pH of 7, temperature of 37 ⁰C, salinity of 20 g.L-1 NaCl and initial concentration of 5 mM selenate were found to be the best at promoting growth. To determine the optimum conditions for the reduction of selenium, the amount of Se(0) recovered from the plug after 16 hours of incubation was measured. A pH of 8, temperature of 37 ⁰C and salinity of 5 g.L-1 resulted in the most Se(0) recovered. The kinetics of the reduction of Se(VI) to Se(0) was found to follow the adapted Monod equation. An increase in the initial Se(VI) concentration positively affected the reduction rate indicating that substrate saturation had not yet been reached. One kmax could be fitted to each of the two reactions but not one Ks. It was found that Ks decreased with increasing initial selenate concentration. Visually it can be deduced that inhibition starts playing a role in the reduction of selenate at a concentration of 4 mM. Pseudomonas stutzeri NT-I is an exemplary selenium reducing agent and deserves more attention, not only for industrial application but also in the research world, for further understanding of the complex mechanism behind metal reduction in bacteria.Dissertation (MEng)--University of Pretoria, 2017.
Chemical Engineering
MEng
Unrestricted
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Lopez, Susana Sorina. "Chiral Boro-Phosphates in Asymmetric Catalysis: 1,4-reduction of Enones and Reductive Aldol." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6305.
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The biological activity of the pharmaceutical drugs often depends on how it fits with a receptor making stereochemistry a key component. Selective reactions can limit or avoid the mixture of enantiomers obtained. One such reaction is the selective reduction of a carbon-carbon double bond in the presence of a carbonyl. Although efficient, current asymmetric synthesis methods have limitations such as harsh reaction conditions, the high costs of chiral catalysts and the toxicity of the metal-based catalysts. Catalysts derived from small organic molecules have become an attractive alternative which have been explored more rigorously in recent years. Using a BINOL-derived boro-phosphate catalyst, we have developed a methodology that selectively reduces the carbon-carbon double bond of linear α, β-unsaturated ketones, exclusively giving the corresponding saturated ketone. To the best of our knowledge, this reaction is the first of its kind to accomplish this transformation and results give high yields of >93% and enantioselectivities >90% at room temperature. Furthermore, the products of this novel reaction can be subjected to a choice electrophile, in example benzaldehyde, to afford diastereoselective tertiary alcohol products with enantioselectivities of >88% and diastereoselectivities of up to 99:1.
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Chan, Ming-Yan. "Video encoder complexity reduction /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20CHANM.
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Linch, William Divine. "On superspace dimensional reduction." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2844.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2005.Thesis research directed by: Physics. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Akbay, Gokhan. "Function, Reduction And Normativity." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/3/12611917/index.pdf.
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Normativity of biological functions create a serious obstacle against the reduction of functional biology into molecular biology. Normativity of biological entities has two interconnected sources. One is the internal complexity and self organization demonstrated by the organism. The second source is external to the organism: Natural selection. An organism adapts to its environment by its internal autonomy. Species or populations adapt by natural selection. If these two sources of normativity can be reduced to statistical generalities achieved by theoretical models, reductionism will prevail.
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Fransson, Henrik. "Active Noice Reduction headset." Thesis, KTH, Reglerteknik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-105714.
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Conventional (passive) headsets used in propeller aircrafts are reasonably good at attenuating mid to high frequency noise, but fail to achieve good attenuation in the low frequency region (below approximately 300 Hz). Active Noise Reduction (ANR) improves the low frequency attenuation by introducing an anti-noise signal creating destructive interference thus decreasing the residual noise level. The aim of this thesis is to develop and implement a digital narrowband active noise reduction headset that works properly in aircrafts and not only in a laboratory environment. The implementation is based on a narrowband ltered-X least mean squares (FXLMS) algorithm where the tonal components in the noise spectrum are synthesized for use as reference signals to the algorithm. The controller is implemented in a parallel fashion where each tonal component is handled separately. The system is built into a headset and laboratory tests show that the algorithm can handle ve simultaneous tonal components with an adaptation time of less than one second. Aircraft tests show peak attenuation of 17 dB in both singleand twin-engine aircrafts thus fullling the requirements. Simulations and true performance show some minor discrepancies which are explained and discussed.
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Vihman, Virve-Anneli. "Valency reduction in Estonian." Thesis, University of Edinburgh, 2004. http://hdl.handle.net/1842/25272.
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Theories of voice based on a model of passivisation such as that exhibited by English tend to characterise valency modifications as primarily a syntactic phenomenon, involving the mapping of semantic roles to non-canonical syntactic argument positions. This dissertation finds such an approach insufficient to account for the observed phenomena in the more complex domain of voice in Estonian. The thesis provides a thorough description of the Estonian voice category, through an in-depth study of four valency-reducing constructions: the impersonal, personal passive, generic apersonal, and anticausative. These all involve semantic and lexical-level changes to the argument structure of a predicate. In order to arrive at a satisfactory theoretical account of voice in Estonian, the analysis must consider semantic and pragmatic information alongside the realignment of syntactic rules linking grammatical functions with argument places. The status of verbal arguments undergoing demotion in valency-changing operations is shown to be crucial to the interpretations that the various constructions give rise to. The thesis establishes a hierarchy of implicit arguments as a key element of these differnces in interpretation. The impersonal argument, although non-overt, is shown to be psychologically and linguistically salient, being present for both semantic interpretation and such syntactic purposes as anaphoric reference. The impersonal actor is argued to be only slightly demoted, the more important property assigned to the actor argument of impersonals being that of non-specificity. Following the impersonal on the proposed Demotion Hierarchy is the personal passive, with a true demoted agent, which can, however, be re-established through an agentive adverbial. Generic apersonal constructions have a less accessible actor referent, whose interpretation crucially involves pragmatic inferencing. The anticausative retains only a single undergoer argument in its logical structure, which reveals both proto-agent and proto-patient characteristics. Only this derivationally formed predicate truly deletes its actor argument.
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Purssell, Tanis Jane. "Modulus reduction dynamic analysis." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25136.
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A semi-analytical method of dynamic analysis, capable of predicting both the magnitude and pattern of earthquake induced deformations, is presented. The analysis is based on a modulus reduction approach which uses a reduced modulus to simulate the softening induced in soils during cyclic loading. The effects of the inertia forces developed during dynamic loading on the induced deformations are also included through an appropriate selection of the reduced modulus.
The reduced modulus is utilized in a static stress-strain analysis to predict the magnitude and pattern of the deformations induced during earthquake loading. The appropriate modulus reduction is determined from laboratory tests on undisturbed soil samples. Three methods of computing a suitable post-cyclic modulus were investigated but only the cyclic strain approach, in which the modulus is determined from cyclic loading tests that duplicate the field stress conditions, yields reductions of sufficient magnitude to provide realistic estimates of earthquake induced deformations.
The modulus reduction analysis was used to predict the deformations occurring during dynamic loading of a model tailings slope in a laboratory shaking table test and of the Upper San Fernando Dam during the earthquake of February, 1971. These studies showed that the modulus reduction analysis is capable of reproducing the dynamically induced deformations and that reductions in the modulus of up to 1000 times may be required. Unfortunately, limitations of the testing equipment and inadequacies in the available data required that the appropriate modulus reductions could not be determined entirely through laboratory and field investigations. Some assumptions were necessary in selecting the reduced modulus values used in the analyses. Although these case studies were, hence, unable to provide full verification of the proposed method, they do demonstrate the reliability and simplicity of the analysis as a method of assessing the performance of soil structures during earthquake loading.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Falkman, Patrik. "Efficient reduction over threads." Thesis, KTH, Teoretisk fysik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-49818.
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The increasing number of cores in both desktops and servers leads to a demand for efficient parallel algorithms. This project focuses on the fundamental collective operation reduce, which merges several arrays into one by applying a binary operation element wise. Several reduce algorithms are evaluated in terms of performance and scalability and a novel algorithm is introduced that takes advantage of shared memory and exploits load imbalance. To do so, the concept of dynamic pair generation is introduced which implies constructing a binary reduce tree dynamically based on the order of thread arrival, where pairs are formed in a lock-free manner. We conclude that the dynamic algorithm, given enough spread in the arriving times, can outperform the reference algorithms for some or all array sizes.
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Sutton, Patrick James. "The dimensional-reduction anomaly." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ59681.pdf.
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Gara, Matthew. "Oxygen reduction on platinum." Thesis, University of Oxford, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.665289.
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Proton exchange membrane (PEM) fuel cells have the potential to provide a clean and convenient source of power for applications such as vehicle transport. At their heart lies a platinum catalyst which is used to reduce oxygen to water. Although platinum is expensive it is the best elemental catalyst for the reaction. In order to make better use of the platinum and reduce production costs, nanoparticulate platinum is dispersed onto a carbon support. This results in a greater surface area per gram of platinum used. Efforts to improve the performance of fuel cells and make them cost effective have so far revolved around increasing the surface area. However in doing this the inter-particle spacing and diffusional characteristics of the catalyst have been ignored. In order to address this oversight, this thesis takes a novel bottom up approach to better understanding the oxygen reduction reaction on nanoparticulate platinum, supported on carbon. By using a model system and simulating the diffusional environment, this work reveals new insights into the oxygen reduction reaction. In Chapter 1 the fundamental electrochemical principles which underpin the subsequent work shall are examined. Chapter 2 begins with a look at the history of fuel cell development, before assessing the modern PEM fuel cell and the challenges faced in the present day to make it ·a viable power source. In Chapter 3 carbon electrode materials are assessed with a view towards their use as a substrate for platinum ~atalysts. The results gained f:rom , ~~is prove useful in later chapters and are both novel and insightful for the selection of PEM fuel cell catalyst supports. In Chapters 4 and 5 voltammetry at nanomaterial modified electrodes are extensively analysed, using electrochemical simulation techniques. This reveals that diffusion can play a role in effects which are assumed to be purely kinetic. From this a major flaw is exposed in the currently accepted measures of oxygen reduction catalyst activity. Chapter 6 brings the information garnered from the previous chapters together. In this chapter nanoparticulate platinum dispersed onto a flat carbon substrate is used as a model system of a typical oxygen reduction catalyst. The resulting voltammetry from the model surfaces is then fitted effectively to results from electrochemical simulations, paying close attention to the diffusional environment around the nanoparticles. This approach leads to a key finding which had hitherto gone unrecognised.
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Kang, Keebom. "AVCAL reduction analysis model." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/26391.
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Hayes, Matthew J. "Artefact reduction in photoplethysmography." Thesis, Loughborough University, 1998. https://dspace.lboro.ac.uk/2134/7094.
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The use of optical techniques in biomedical monitoring and diagnosis is becoming increasingly widespread, primarily because of the non-invasive nature of optically derived measurements. Physiological analysis is usually achieved by characterisation of the spectral or temporal properties of the interaction between light and the anatomy. Although some optical measurements require complex instrumentation and protocols, recent technological advances have resulted in robust and compact equipment that is now used routinely in a multitude of clinical contexts. Unfortunately, these measurements are inherently sensitive to corruption from dynamic physical conditions or external sources of light, inducing signal artefact. Artefact is the primary restriction in the applicability of many optical measurements, especially for ambulatory monitoring and tele-medicine. The most widely used optical measurement is photoplethysmography, a technique that registers dynamic changes in blood volume throughout the peripheral vasculature and can be used to screen for a number of venous disorders, as well as monitoring the cardio-vascular pulse wave. Although photoplethysmographic devices are now incorporated into many patient-monitoring systems, the prevalent application is a measurement known as pulse oximetry, which utilises spectral analysis of the peripheral blood to estimate the arterial haernoglobin oxygen saturation. Pulse oximetry is well established as an early warning for hypoxia and is now mandatory under anaesthesia in many countries. The problem of artefact is prominent in these continuous monitoring techniques, where it is often impossible to control the physical conditions during use. This thesis investigates the possibility of reducing artefact corruption of photoplethysmographic signals in real time, using an electronic processing methodology that is based upon inversion of a physical artefact model. The consequences of this non-linear artefact reduction technique for subsequent signal analysis are discussed, culminating in a modified formulation for pulse oximetry that not only has reduced sensitivity to artefact but also possesses increased generality. The design and construction of a practical electronic system is then used to explore both the implementation issues and the scope of this technique. The performance of artefact reduction obtained is then quantified under realistic experimental conditions, demonstrating that this methodology is successful in removing or reducing a large proportion of artefact encountered in clinically relevant situations. It is concluded that non-linear artefact reduction can be applied to any photoplethysmographic technology, reducing interpretation inaccuracies that would otherwise be induced by signal artefact. It is also speculated that this technology could enable the use of photoplethysmographic systems in applications that are currently precluded by the inherent severity of artefact.
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Whiting, Daniel. "Meaning, use and reduction." Thesis, University of Reading, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428294.
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Jurkauskas, Valdas 1966. "Copper-catalyzed conjugate reduction." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/17742.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2004.Includes bibliographical references.
Chapter 1. A highly enantioselective catalyst for the asymmetric conjugate reduction of a,- unsaturated cyclic ketones was generated upon combination of catalytic amounts of CuCl, NaOt-Bu, and a chiral bis-phosphine with poly(methylhydrosiloxane) (PMHS) as the stoichiometric reductant. In this process, chiral 3-alkylcyclopentanones were isolated in high enantiomeric excess (ee =/> 92%) and in moderate to excellent yields (42-91%). Chapter 2. Kinetic resolution, with good selectivity factors (25-52), was achieved by conjugate reduction with catalytic CuCl/NaOt-Bu/(S)-p-tol-BINAP and stoichiometric quantities of PMHS. When stoichiometric amounts of NaOt-Bu and t-BuOH were included in the reaction mixture, rapid racemization of the starting material occurred allowing for the dynamic kinetic resolution of the cyclopentenone substrates. In this process, chiral 2,4-dialkylcyclopentanones were isolated with high stereoselectivity (ee =/> 91%, dr=/>90:10) and in high yield (=/> 89%). Chapter 3. An N-heterocyclic carbene-copper chloride complex was prepared and used to catalyze the conjugate reduction of [alpha], [beta]-unsaturated carbonyl compounds. The combination of catalytic amounts of N-heterocyclic carbene-copper chloride complex and NaOt-Bu with PMHS as the stoichiometric reductant generates an active catalyst for the 1,4-reduction of tri- and tetrasubstituted a,f3-unsaturated esters and cyclic enones. The active catalytic species can also be generated in situ from 1,3-bis(2,6-di-isopropylphenyl)-imidazolium chloride and CuCl2.2H20 in the presence of NaOt-Bu and PMHS.
by Valdas Jurkauskas.
Ph.D.
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Li, Qian. "Electrochemical reduction of oxygen." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:2f37a1ae-dab0-4581-a8fd-e01ce59246c4.
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The main aim of the work reported is the design of proof-of-concept of at point-of-use hydrogen peroxide electrogeneration from air. The experimental work discussed within this thesis explores five major areas: the kinetics of electrocatalysis, ion-pairing, change of solvent media, the electrode surface modication by a redox mediator, and the electrochemical reduction of oxygen within enhanced mass transport systems. The electrocatalytic rates and mass transport of two oxygen reduction redox meditors, viz. anthraquinone and methyl viologen, are studied in aqueous solutions. The investigation is facilitated through the use of a boron-doped diamond electrode, allowing the catalytic response to be clearly delineated from that of the direct oxygen reduction process. The use of simulation software is highlighted in combination with experimental voltammograms to extract kinetic data. Specifically, the voltammetric features, such as the `reverse' peak and the `split waves', are given particular attention. Consequently, it is possible to deconvolute the electrocatalytic reaction mechanisms. The reactivity of the viologen radical cation is comparable to the semiquinone radical anion in aqueous solution ((4.8~6)x10^9 M^-1 s^-1), but over a far wider pH range (pH 2.5 - pH 8.5). The change of local proton concentration, and sequential electron transfers play key roles here. Moreover, the reduced reactivity of semiquinone is observed upon formation of ion-pairs with tetrabutylammonium cations in alkaline solutions. The electro-reduction of oxygen and its mediated pathways are also investigated in non-aqueous media; in particular the thermodynamics, the kinetics, and mass transport involved in these processes. Through a variable temperature study in electrolytic acetonitrile solution, the oxygen dissolution is quantitatively shown to be an endothermic process. Moreover, the diffusion coeficients and concentration of oxygen upon change of acetonitrile mole fraction is also explored in water-acetonitrile mixtures. The rates of bimolecular reactions are extracted from simulation programs, involving semiquinone in anhydrous acetonitrile and viologen radical cation in ethanol, and show a 3 - 4 orders of magnitude reduction compared to that in aqueous solution. Although the solubility of oxygen is ca. 6 - 8 times larger in non-aqueous solvents, the much reduced homogeneous rates limit the electrogeneration of hydrogen peroxide in pure organic media. Novel surface modification methodologies for graphitic surfaces with covalently attached anthraquinonyl groups are studied and characterised. The anthraquinonyl-modified carbon surfaces show much reduced overpotentials required for oxygen reduction. In the final chapter, utilising the new surface modification methodology and novel designs, two gravity-feed flow cells for electrochemical reduction of oxygen in aqueous solutions are proposed and characterised, one based upon the tubular electrode geometry. The other exhibits much enhanced current conversion by using a porous reticulated vitreous carbon electrode. The latter may provide a prototype hydrodynamic system to produce dilute hydrogen peroxide solution at point-of-use.
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Lubchak, I. V., and A. Koneva. "Inhibitors for cholesterol reduction." Thesis, Sumy State University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/45956.
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Cardiovascular diseases (CVDs) are a group of disorders of the heart and blood vessels. Many of them involve atherosclerosis, which causes most heart attacks and strokes. Cardiovascular diseases are the leading cause of death globally. Nearly 2,200 Americans die of cardiovascular disease daily, with an average of one death occurring every 40 seconds. However, elevated levels of certain forms of cholesterol are some of the primary drivers in the development of some CVDs.
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Munster, Drayton William. "Sensitivity Enhanced Model Reduction." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23169.
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In this study, we numerically explore methods of coupling sensitivity analysis to the reduced model in order to increase the accuracy of a proper orthogonal decomposition (POD) basis across a wider range of parameters. Various techniques based on polynomial interpolation and basis alteration are compared. These techniques are performed on a 1-dimensional reaction-diffusion equation and 2-dimensional incompressible Navier-Stokes equations solved using the finite element method (FEM) as the full scale model. The expanded model formed by expanding the POD basis with the orthonormalized basis sensitivity vectors achieves the best mixture of accuracy and computational efficiency among the methods compared.Master of Science
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Lu, Huajun. "Reduction of elliptic curves." Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14129.
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Soit E une courbe elliptique sur un corps de valuation discrètecomplet K à corps résiduel algbriquement clos. Alors E a réduction semi-stable surune extension minimale L/K, galoisienne de groupe de Galois G. Soient O_{K} , O_{L} les anneaux de valuations respectives de K et L, et X , X' les modèles réguliers minimaux de E sur O_{K} et O_{L} respectivement.Premièrement nous montrons que pour tout entier naturel n, la fibre fermée infinitésimale X_{n} est déterminée par l'action du groupe G sur X'_{n+l} pour unentier naturel l assez grand (ne dépendant que du discriminant de L/K sile type de réduction de E n'est pas I*_{r} ). Deuxiémement, nous classifions àisomorphisme près la fibre fermée X_{0} en tant que courbe sur le corps résiduelde K, lorsque la caractéristique résiduelle est nulle ou au moins égale à 7. Cette classification est plus fine que la classification par le type à la Kodairaet NéronSuppose E is an elliptic curve over a complete discrete valuationfield K whose residue field k is algebraically closed. Then E has semi-stablereduction after a minimal field extension L/K, moreover L/K is Galois andlet G be the Galois group. Let O_{K} and O_{L} be the ring of integers of K andL respectively. Let X (resp. X ') be the minimal regular model of E over O_{K}(resp. O_{L} ). In the first part of thesis, we prove that for all natural integersn, the infinitesimal fiber X_{n} is determined by the G-action on O_{K}-schemeX'_{n+l} for some positive integer l (depending only on the discriminant of L/Kif the reduction type of E is not I*_{r} ). In the second part of thesis, we classifythe special fiber X_{0} up to isomorphisms as k-curves when Char(k) >= 7. This classification is finer than the classification by Kodaira and Néron
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Yang, Jing. "Visual hierarchical dimension reduction." Link to electronic thesis, 2002. http://www.wpi.edu/Pubs/ETD/Available/etd-0109102-132821.
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Thesis (M.S.)--Worcester Polytechnic Institute.Keywords: hierarchy; sunburst; dimension reduction; high dimensional data set; multidimensional visualization; parallel coordinates; scatterplot matrices; star glyphs. Includes bibliographical references (p. 86-91).
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Ponton, Rhys. "Evidence based harm reduction." Thesis, University of Bath, 2006. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438656.
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Review of the literature demonstrated that knowledge surrounding the process of illicit drug injection preparation is limited. A better understanding of the details of injection preparation methods could inform study of the risks and complications, as well as the development of harm reduction advice. This project had two main objectives: To characterise the injection preparation process in detail, then to attempt to quantify the risks posed by these injections through laboratory investigations. The project had specific focus on the use of the acids by injectors to increase the solubility of insoluble illicit drugs. To study injection preparation, a novel interview was designed to record the methods that a cohort of injectors used to prepare their injections of heroin and 'crack' cocaine. The interview incorporated two separate sections: firstly a semi-structured questionnaire, then observation of participants preparing an inert 'fake drug' for injection using their usual preparation procedure for real drug. The injector interviews documented the use of acids by injectors in detail. The injection preparation demonstration enabled a complete characterisation of the preparation procedures for heroin, crack and speedball injections and enabled the development of a standardised method by which injections using real drug samples could be reproduced in the laboratory. Prepared injections were subjected to a number of assays to evaluate their properties. These assays allowed a comparison with pharmaceutically prepared injections (pharmacopoeia standards) to provide some quantification of risk. Investigations were conducted into the drug content, the microflora, the particulate content and the physical characteristics of the injections. Electrospray mass spectrometry was used to identify the components within illicit heroin samples. This methodology has never before been used to examine illicit drug samples. The project developed microbiological investigation techniques that enabled the isolation and identification of micro-organisms within drug injection solutions. Particulate content of injection solutions was found to be high, and the use of rudimentary illicit filters was shown to add to this. The use of filters made specifically for illicit drug users could significantly reduce this content. Overall, no significant risks were identified and this supports current harm reduction advice which was not based on any published research.
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Hartley, Benjamin C. "Recent advances in tandem reductive processes." Thesis, University of Bath, 2009. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.500753.
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The research presented herein is concerned with the exploration of tandem processes initiated by the conjugate reduction of Michael acceptors, encompassing the asymmetric reductive Dieckmann reaction and the two-carbon homologation of aldehydes by two complementary methodologies. Chapter 1 introduces the area of transition metal catalysed tandem reductive processes as a tool for carbon-carbon bond formation. An extensive discussion of this methodology is included and recent advances in the area are highlighted. Chapter 2 discusses the initial study into the asymmetric reductive Dieckmann condensation. 3,3’-Disubstituted 4-oxopyrrolidines were synthesised in up to 93% ee using both molybdenum and copper catalysis. Chapter 3 describes the novel molybdenum-catalysed two-carbon homologation of aldehydes by the reduction of alkylidene Meldrum’s acid derivatives. No over reduction to the corresponding alcohol is observed, as the aldehyde functionality remains protected until hydrolysis. Chapter 4 discusses the mild, expeditious amine promoted reduction of cyclic malonates to β-substituted propionaldehydes. The synthetic utility of the methodology is demonstrated by the synthesis of γ-substituted propylamines in a one-pot hydrosilylation/reductive amination process. Chapter 5 describes the synthesis and characterisation for the compounds discussed in chapters 2, 3 and 4.
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Coby, Aaron J. "Microbial iron-(hydr)oxide reduction effects on zinc speciation and interactions with nitrate reduction /." [Bloomington, Ind.] : Indiana University, 2005. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3163021.
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Thesis (Ph.D.)--Indiana University, School of Public Environmental Affairs, 2005.Source: Dissertation Abstracts International, Volume: 66-02, Section: B, page: 0765. Adviser: Flynn W. Picardal. Title from dissertation home page (viewed Oct. 18, 2006).
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Granier, Pierre. "Reduction, aménagement-reduction du temps de travail et emploi : contribution à une analyse théorique." Aix-Marseille 2, 1992. http://www.theses.fr/1992AIX24005.
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Slagbrand, Tove. "Development and Applications of Molybdenum-Catalyzed Chemoselective Amide Reduction." Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-145560.
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This thesis covers the development of catalytic methodologies for the mild and chemoselective hydrosilylation of amides. The first part describes the investigation of the Mo(CO)6-catalyzed reduction of carboxamides. It was found that the reduction could be controlled by tuning the reaction temperature and either amines or aldehydes could be obtained selectively. The system showed an unprecedented chemoselectivity and the amide reduction could take place in the presence of other reducible functional groups such as ketones, aldehydes, and imines. Moreover, the transformation could be performed on a preparative scale and was further employed in the synthesis of Donepezil, a pharmaceutical drug used in the treatment of Alzheimer´s disease. The third chapter concerns the development of the Mo(CO)6-mediated hydrosilylation protocol for the reduction of carboxamides containing acidic α-hydrogens. In this case, enamines were formed and a high level of chemoselectivity was observed. Enamines containing sensitive functional groups such as ketones, aldehydes and imines were generated. The enamines were not isolated but used in subsequent catalytic reductive functionalization of amides, which is described in the last part of the thesis (Chapters 4 – 7). The in situ formed enamines were reacted with a wide variety of electrophiles, generating heterocyclic compounds as triazolines, triazoles, 4,5-dihydroisoxazoles and pyrimidinediones. N-sulfonylformamidines as well as thioacrylamides could also be prepared with this approach. The protocols for the synthesis of triazolines, triazoles and N-sulfonylformamidines could additionally be performed on a preparative scale, showing the practicality of the methodology.
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Bolelli, Maria Virginia. "Diffusion Maps for Dimensionality Reduction." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18246/.
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In this thesis we present the diffusion maps, a framework based on diffusion processes for finding meaningful geometric descriptions of data sets. A diffusion process can be described via an iterative application of the heat kernel which has two main characteristics: it satisfies a Markov semigroup property and its level sets encode all geometric features of the space. This process, well known in regular manifolds, has been extended to general data set by Coifman and Lafon. They define a diffusion kernel starting from the geometric properties of the data and their density properties. This kernel will be a compact operator, and the projection on its eigenvectors at different instant of time, provides a family of embeddings of a dataset into a suitable Euclidean space. The projection on the first eigenvectors, naturally leads to a dimensionality reduction algorithm. Numerical implementation is provided on different data set.
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Short, Daniel R. "AH-64 Apache cost reduction." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2000. http://handle.dtic.mil/100.2/ADA377413.
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Nuszkowski, John. "Staten Island ferry emissions reduction." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4169.
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Thesis (M.S.)--West Virginia University, 2005.Title from document title page. Document formatted into pages; contains xi, 94 p. : ill. (some col.), col. map. Includes abstract. Includes bibliographical references (p. 74-79).
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Niesdroy, Henning [Verfasser]. "Geometric reduction theory / Henning Niesdroy." Bielefeld : Universitätsbibliothek Bielefeld, 2016. http://d-nb.info/1096457164/34.
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Igiehon, Uwagboe Osamede. "Carbothermic reduction of complex sulphides." Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/46358.
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Krasik, Pavel. "Asymmetric ruthenium catalyzed reduction reactions." Thesis, University of Ottawa (Canada), 1994. http://hdl.handle.net/10393/6562.
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Flaaten, Marcus. "Efficient polygon reduction in Maya." Thesis, Linköpings universitet, Medie- och Informationsteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-121687.
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Reducing the number of vertices in a mesh is a problem that if solved correctly can save the user a lot of time in the entire process of handling the model. Most of the solutions today are focused on reducing the mesh in one big step by running a separate application. The goal of this implementation is to bring the reduction application into the users workspace as a plugin. Many of the modellers in the various computer graphics industries use Autodesk Maya the plugins intention is to create a efficient tool which also give the modellers as much freedom as possible without the need to ever leave Mayas workspace. During the process the possible issues and solutions of creating this tool in Maya will also examined to help introduce the process of creating a tool for Maya. This plugin has the potential to improve on the existing reduction tool in Maya by giving the user more options and a more exact solution.
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Khosla, Nitin, and n/a. "Dimensionality Reduction Using Factor Analysis." Griffith University. School of Engineering, 2006. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20061010.151217.
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In many pattern recognition applications, a large number of features are extracted in order to ensure an accurate classification of unknown classes. One way to solve the problems of high dimensions is to first reduce the dimensionality of the data to a manageable size, keeping as much of the original information as possible and then feed the reduced-dimensional data into a pattern recognition system. In this situation, dimensionality reduction process becomes the pre-processing stage of the pattern recognition system. In addition to this, probablility density estimation, with fewer variables is a simpler approach for dimensionality reduction. Dimensionality reduction is useful in speech recognition, data compression, visualization and exploratory data analysis. Some of the techniques which can be used for dimensionality reduction are; Factor Analysis (FA), Principal Component Analysis(PCA), and Linear Discriminant Analysis(LDA). Factor Analysis can be considered as an extension of Principal Component Analysis. The EM (expectation maximization) algorithm is ideally suited to problems of this sort, in that it produces maximum-likelihood (ML) estimates of parameters when there is a many-to-one mapping from an underlying distribution to the distribution governing the observation, conditioned upon the obervations. The maximization step then provides a new estimate of the parameters. This research work compares the techniques; Factor Analysis (Expectation-Maximization algorithm based), Principal Component Analysis and Linear Discriminant Analysis for dimensionality reduction and investigates Local Factor Analysis (EM algorithm based) and Local Principal Component Analysis using Vector Quantization.
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Wijnen, Joseph Anna Guillaume. "Exercise and cardiovascular risk reduction." Maastricht : Maastricht : Universitaire Pers Maastricht ; University Library, Maastricht University [Host], 1994. http://arno.unimaas.nl/show.cgi?fid=6547.
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Panudulkitti, Panupong. "Urbanization and Poverty Reduction Outcomes." Digital Archive @ GSU, 2008. http://digitalarchive.gsu.edu/econ_diss/45.
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This dissertation attempts to examine the effect of urbanization on poverty reduction outcomes by considering various dimensions of poverty and channels of reducing poverty. First, we develop a theoretical model in order to infer a relationship between urbanization and poverty reduction outcomes. Specifically, it shows an optimal level of urbanization to properly allocate basic public infrastructure and promote pro-poor growth. Second, we conduct empirical analysis on international data to examine the testable hypotheses that are derived from the theoretical model. Further, we explore the “channeled effects” of urbanization on basic education and health by the IV estimation and on productivity by the dynamic panel GMM estimation. As the theoretical model suggests, our results exhibit the statistically significant relationship in a non-linear form between urbanization and poverty. In addition, we explore the impact of urbanization on poverty reduction outcomes in different regions in order to see the various magnitudes of urbanization effects among regions.
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Slobodov, Sergei. "Dimensional reduction and spacetime pathologies." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/30364.
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Dimensional reduction is a well known technique in general relativity. It has been used to resolve certain singularities, to generate new solutions, and to reduce the computational complexity of numerical evolution. These advantages, however, often prove costly, as the reduced spacetime may have various pathologies, such as singularities, poor asymptotics, negative energy, and even superluminal matter flows. The first two parts of this thesis investigate when and how these pathologies arise.
After considering several simple examples, we first prove, using perturbative techniques, that under certain reasonable assumptions any asymptotically flat reduction of an asymptotically flat spacetime results in negative energy seen by timelike observers. The next part describes the topological
rigidity theorem and its consequences for certain reductions to three dimensions, confirming and generalizing the results of the perturbative approach. The last part of the thesis is an investigation of the claim that closed timelike
curves generically appearing in general relativity are a mathematical artifact of periodic coordinate identifications, using, in part, the dimensional
reduction techniques. We show that removing these periodic identifications results in naked quasi-regular singularities and is not even guaranteed to get rid of the closed timelike curves.
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Langlais, Joseph. "Strontium extraction by aluminothermic reduction." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22447.
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The Melt-Leach-Evaporation (MLE) process is under development for the extraction of valuable Group IA or IIA metals of the Periodic Table, such as lithium, calcium, magnesium and strontium. The process consists of mixing and contacting the value metal source material, which might be an ore or concentrate, with an excess of molten metal which is acting as a reductant and lixiviant. In the process, the value metal extracted from the source material is dissolved in the excess molten metallic solvent and is subsequently extracted as a vapour by vacuum distillation. The vapour is condensed and recuperated in the metallic state.An experimental program involving eight experiments was carried out. The experimental procedure consisted in essence of melting the aluminum reductant in a crucible and adding the source material, SrCO$ sb3,$ and other reactant (Mg or Bi). (Abstract shortened by UMI.)
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David, Chantal. "Supersingular reduction of Drinfeld modules." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41268.
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Let $ phi$ be a rank 2 Drinfeld A-module over the ring A of polynomials over some finite field $F sb{q}$. We give a bound on the norm of those primes p of A which are factors of $P sb{d}(j sb phi)$ for two distinct polynomials d $ in$ A. We then show that the number of supersingular primes of $ phi$ with norm smaller than x is $ gg log log$ x. We investigate the endomorphism rings of supersingular Drinfeld A-modules over finite fields. Under a mild hypothesis, this leads to an upper bound of $x sp{3/4} log sp2 x$ for the number of supersingular primes of $ phi$, with even degree, and norm smaller than x. Finally, we present the problem of the average distribution of supersingular primes of Drinfeld modules.