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Wingard, David W. "Assessing ASR potential of hardened concrete and the use of rice husk ash to mitigate ASR." Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1202499589/.
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Park, Alex S. (Alex Seungryong) 1979. "ASR dependent techniques for speaker recognition." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/87287.
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Norberg, Sara, and Hadeel Sawasa. "Inverkan av alkalisilikareaktion (ASR) på lamelldammars bärförmåga." Thesis, Uppsala universitet, Byggteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-229185.
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Dammar är en viktig konstruktion i Sverige och i världen bland annat för vattenförsörjning, reglering av flöden och elproduktion. En expansion på grund av en alkalisilikareaktion (ASR) i en betongdamm kan leda till många problem. Bland annat kan det uppstå läckage av vatten och problem med öppning och stängning av luckor. Mycket forskning har lagts ner på att ta reda på hur ASR påverkar hållfastheten och bärförmågan hos betong. Detta examensarbete syftar till att genom en litteraturstudie visa hur bärförmågan hos en lamelldamm påverkas av en alkalisilikareaktion. I den första delen beskrivs vad en lamelldamm är och principer för dimensioneringen av en monolit. I den andra delen visas hur ASR uppstår och vad reaktionen kan leda till. Det visas även på sätt att hämma reaktionen. I den tredje delen visas på ett sätt att undersöka och uppskatta skadan av ASR i en lamelldamm. I den fjärde delen visas på hur ASR påverkar hållfastheten hos oarmerad betong och även bärförmågan i en armerad konstruktion. Resultaten visar att även om den oarmerade betongens hållfasthet påverkas mycket av ASR påverkas inte bärförmågan hos en lamelldamm i samma utsträckning. Detta gäller dock under förutsättning att dammen är tillräckligt armerad med längsgående armering i båda riktningar och att byglar är insatta. Att bärförmågan inte påverkas i stor utsträckning gäller även endast om expansionen i betongen är låg till måttlig.<br>Dams are an important structure in Sweden and around the world regarding water supply, regulation of flows and power generation. An expansion due to an alkalisilicareaction (ASR) in a concrete dam can lead to many problems. Among other things it may cause leakage of water, and problems with opening and closing of gates. A lot of research has been done to find out how ASR affects the strength and load carrying capacity of concrete. This thesis aims, through a literature review, to show how the load carrying capacity of a buttress dam is influenced by an alkalisilicareaction. The first part describes what a buttress dam is and principles for the design of a monolith. The second part shows how ASR occurs and what the reaction could result in. It also shows ways to inhibit the reaction. The third part displays a way to investigate and estimate the damage of ASR in a buttress dam. The fourth section shows how ASR affects the strength of unreinforced concrete and the load carrying capacity of a reinforced structure. The results show that while the unreinforced concrete strength is greatly affected by ASR the resistance of a buttress is not affected to the same extent. However, this is provided that the dam is sufficiently reinforced with longitudinal reinforcement in both directions and that shear reinforcement are present. This also applies only if the expansion in the concrete is low to moderate.
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Olivares, Cotal José Luis. "Plataforma de aprendizaje de segundo idioma con ASR." Tesis, Universidad de Chile, 2013. http://www.repositorio.uchile.cl/handle/2250/113043.
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Ingeniero Civil Electricista<br>Las redes de datos que permiten acceder a la información desde cualquier lugar del mundo están cada vez más cerca del publico en general. Este hecho, asociado al empleo de browser o navegadores ampliamente difundidos y de fácil uso, posibilita el desarrollo de sistema de enseñanza en linea.
Esta memoria se centra en el desarrollo de una plataforma de enseñanza basada en las redes y sistemas Web. Se emplea la técnica de Reconocimiento Automático de Voz (Automatic Speech Recognition, ASR), una base de datos relacional llamada Postgresql y un servidor HTTP cuyo nombre es Tomcat. Para el desarrollo se emplearon lo modelos Cliente Servidor, Vista Controlador y la Arquitectura AJAX. La estructura de la base de datos y las lecciones se diseñaron de manera que futuras revisiones se puedan realizar con facilidad. Se destaca el empleo de un formato ligero y compatible para la transferencia de datos por medio de JavaScript Object Notation. El programa permite el almacenamiento de las lecciones, el registro de la información de uso y el envío-recepción de datos asincrónicos entre el servidor y el cliente.
El trabajo finaliza con un análisis de estabilidad y robustez del sistema por medio de la carga de 150 usuarios simultáneos. Para realizar esta prueba fue empleado Jmeter, un software gráfico para el análisis de carga y desempeño de sistemas Web. Como trabajo a futuro se propone el empleo de HTML5 como lenguaje de reemplazo del Applet, para el envío de los datagramas de voz. El sistema al estar basado en servicios se puede configurar para trabajar en paralelo de modo que se está frente a un sistema escalable a nivel de servicios.
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Svensson, Björn. "Modellering av svällande betong : Alkali-silikatreaktion (ASR) i en befintligturbininneslutning." Thesis, Uppsala universitet, Byggteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-208459.
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För att bibehålla elnätet stabilt är det viktigt för elproducenterna attkunna möta samhällets behov av elkraft. Detta behov varierar beroendepå tid på dygnet och även av årstid. Att kunna samla energi då behovetär lågt, för att sedan utvinna och distribuera energi då behovet ökar ärdärför viktigt. Vattenkraft är en av de energikällor som är enklast attreglera. Denna energi är dessutom relativt miljövänlig. Att ha en stabiloch säker vattenkraft är därför viktigt för samhället.I detta examensarbete har vissa problem som kan uppstå i ettvattenkraftverkets studerats, närmare bestämt alkali-silikatreaktion ibetong. Denna reaktion framträder genom att betongen sväller. Tillföljd av detta kan konstruktionen spricka. Detta beror på att en gelbildas när alkalier och kisel reagerar med varandra. Denna gel kan taupp vatten och då svälla.En specifik vattenkraftstation har i detta examensarbete studeratsnärmare, nämligen Malgomaj kraftverk. Detta är en anläggning somligger i ett område där, till skillnad från övriga Sverige, det finnsbergarter som har en medelsnabb reaktion med avseende på alkalikiselreaktion.Att denna geografiska placering blir ett problem beror påatt det stenmaterial som finns att tillgå i vattenkraftstationens närhethar använts som ballast i anläggningens betongkonstruktion.I den vattenkraftstation som studeras har problem iakttagits på grundav svällningar av betongkonstruktionen kring turbinen. För att få enuppskattning om hur vattenkraftstationens deformationer i framtidenkommer att utbildas har en modell av problemområdet byggts uppmed hjälp av finita elementmetoden, en så kallad FEM-modell. Dennamodell kalibreras mot mätdata och ska sedan ligga till grund för enuppskattning av vattenkraftstationens livslängd.Resultatet från undersökningen i detta examensarbete visar attdeformationerna är små men betydande för vattenkraftstationensmöjlighet till att fortsätta sin energiproduktion.<br>To maintain a stable power grid, it is important for electricity producers to meetsociety's need for electricity. This need will vary depending on time of day and eventhe season. Being able to accumulate energy when demand is low, and regain energywhen demand increases, is therefore important. Hydropower is one of the energysources that are easiest to regulate. Having a stable and secure hydropower istherefore important for society.In this thesis one problem that can occur in a hydroelectric plant has been studied,namely alkali-silica reaction (ASR) in concrete. This reaction causes the concrete toswell, due to a formation of gel when alkali and silicon react together.A specific hydropower station has been studied in detail, namely Malgomajhydropower plant. This is a facility that is located in an area where, unlike the rest ofSweden, there are stone materials that have a moderately rapid reaction with respectto the ASR.Problems for this hydroelectric power station have been observed because of swellingof the concrete structure surrounding the turbine. To get an estimate prognosis ofhow the hydropower plant will deform in the future, a finite element method-model(FEM-model) has be created of the problem area. This model is calibrated againstmeasured data and will then form the basis for an appreciation of the hydropowerstation's remaining lifetime.The results in this thesis show that the deformations are small but significant for thehydropower station's opportunity to continue its energy production.
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Gao, Xiao Xiao. "Contribution to the requalification of alkali silica reaction (ASR) damaged structures : assessment of the ASR advancement in aggregates by alkali silica reaction." Thesis, Toulouse, INSA, 2010. http://www.theses.fr/2010ISAT0034/document.
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Afin de répondre aux questions des propriétaires de structures atteintes de réaction alcali-silice (RAS), ce travail se concentre sur une partie d'une méthodologie globale, proposée initialement par le LMDC et EDF, et dont le but est l'étude du comportement mécanique des constructions endommagées par la RAS. Pour atteindre cet objectif, l'avancement chimique de la RAS des granulats récupérés dans les structures affectées doit être évalué. Ainsi, ce travail est consacré à la quantification de la silice potentiellement réactive des granulats, par l'utilisation de deux approches : une approche indirecte par un test d'expansion et une approche directe par des méthodes chimiques. La présentation du manuscrit s'articule autour des points suivants :• Un test d'expansion pertinent et rapide sur mortiers pour relier la quantité de silice réactive à l'expansion mesurée. Les conditions expérimentales suivantes ont été choisies pour tester différentes tailles et natures de granulats, ainsi que différentes tailles d'éprouvettes : solution de NaOH à 1 mol/l et température de conservation de 60°C.• Une méthode chimique rapide de dissolution sélective pour mesurer directement la quantité de silice réactive disponible pour la RAS. La méthode HF / HF+HCl a été trouvé comme étant la plus efficace.• Un modèle chemo-mécanique pour analyser les effets de la taille des granulats et des éprouvettes, et évaluer l'avancement chimique de la réaction.Finalement, une méthodologie est proposée pour calculer la constante cinétique de la réaction dans le cadre de la requalification des structures atteintes de RAS<br>In order to answer the questions of the ASR-affected structures owners, this work focused on a part of a global methodology, which is proposed originally by the LMDC and EDF, aiming to reassess the mechanical behavior of ASR-damaged constructions. To achieve this purpose, the chemical advancement of ASR in the aggregates recovered from the structure should be evaluated. Thus, this work focuses on the assessment of the potentially reactive silica content with two main methods: indirectly by expansion test and directly by chemical methods. The presentation of this manuscript is around the following points: • A relevant and rapid expansion test on mortars to link the reactive silica content to measured expansion. The experimental condition: 1 mol/l NaOH solution conserved at 60°C is chosen to test different aggregate sizes, specimen sizes and natures of aggregate. • A fast chemical method of selective dissolution to measure directly the silica available for ASR. Acid/basic methods are tested and compared; HF / HF+HCl method is found to be the most effective. • A chemo-mechanical model to analyze the effect of aggregate size and specimen size, and evaluate the chemical advancement of ASR. Finally, a methodology is proposed to calculate the kinetics constant in the framework of structural requalification. Key words: alkali-silica reaction (ASR), chemical advancement, reactive silica, expansion test, chemical test, chemo-mechanical model, kinetic constant, selective dissolution
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Podder, Sushil. "Unsupervised Clustering and Automatic Language Model Generation for ASR." Thesis, University of Waterloo, 2004. http://hdl.handle.net/10012/933.
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The goal of an automatic speech recognition system is to enable the computer in understanding human speech and act accordingly. In order to realize this goal, language modeling plays an important role. It works as a knowledge source through mimicking human comprehension mechanism in understanding the language. Among many other approaches, statistical language modeling technique is widely used in automatic speech recognition systems. However, the generation of reliable and robust statistical model is very difficult task, especially for a large vocabulary system. For a large vocabulary system, the performance of such a language model degrades as the vocabulary size increases. Hence, the performance of the speech recognition system also degrades due to the increased complexity and mutual confusion among the candidate words in the language model. In order to solve these problems, reduction of language model size as well as minimization of mutual confusion between words are required. In our work, we have employed clustering techniques, using self-organizing map, to build topical language models. Moreover, in order to capture the inherent semantics of sentences, a lexical dictionary, WordNet has been used in the clustering process. This thesis work focuses on various aspects of clustering, language model generation, extraction of task dependent acoustic parameters, and their implementations under the framework of the CMU Sphinx3 speech engine decoder. The preliminary results, presented in this thesis show the effectiveness of the topical language models.
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Ogun, Sewade. "Generating diverse synthetic data for ASR training data augmentation." Electronic Thesis or Diss., Université de Lorraine, 2024. http://www.theses.fr/2024LORR0116.
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Au cours des deux dernières décennies, le taux d'erreur des systèmes de reconnaissance automatique de la parole (RAP) a chuté drastiquement, les rendant ainsi plus utiles dans les applications réelles. Cette amélioration peut être attribuée à plusieurs facteurs, dont les nouvelles architectures utilisant des techniques d'apprentissage profond, les nouveaux algorithmes d'entraînement, les ensembles de données d'entraînement grands et diversifiés, et l'augmentation des données. En particulier, les jeux de données d'entraînement de grande taille ont été essentiels pour apprendre des représentations robustes de la parole pour les systèmes de RAP. Leur taille permet de couvrir efficacement la diversité inhérente à la parole, en terme de voix des locuteurs, de vitesse de parole, de hauteur, de réverbération et de bruit. Cependant, la taille et la diversité des jeux de données disponibles dans les langues bien dotées ne sont pas accessibles pour les langues moyennement ou peu dotées, ainsi que pour des domaines à vocabulaire spécialisé comme le domaine médical. Par conséquent, la méthode populaire pour augmenter la diversité des ensembles de données est l'augmentation des données. Avec l'augmentation récente de la naturalité et de la qualité des données synthétiques pouvant être générées par des systèmes de synthèse de la parole (TTS) et de conversion de voix (VC), ces derniers sont également devenus des options viables pour l'augmentation des données de RAP. Cependant, plusieurs problèmes limitent leur application. Premièrement, les systèmes de TTS/VC nécessitent des données de parole de haute qualité pour l'entraînement. Par conséquent, nous développons une méthode de curation d'un jeux de données à partir d'un corpus conçu pour la RAP pour l'entraînement d'un système de TTS. Cette méthode exploite la précision croissante des estimateurs de qualité non intrusifs basés sur l'apprentissage profond pour filtrer les échantillons de haute qualité. Nous explorons le filtrage du jeux de données de RAP à différents seuils pour équilibrer sa taille, le nombre de locuteurs et la qualité. Avec cette méthode, nous créons un ensemble de données interlocuteurs de haute qualité, comparable en qualité à LibriTTS. Deuxièmement, le processus de génération de données doit être contrôlable pour générer des données TTS/VC diversifiées avec des attributs spécifiques. Les systèmes TTS/VC précédents conditionnent soit le système sur l'empreinte du locuteur seule, soit utilisent des modèles discriminatifs pour apprendre les variabilités de la parole. Dans notre approche, nous concevons une architecture améliorée basée sur le flux qui apprend la distribution de différentes variables de la parole. Nous constatons que nos modifications augmentent significativement la diversité et la naturalité des énoncés générés par rapport à une référence GlowTTS, tout en étant contrôlables. Enfin, nous avons évalué l'importance de générer des données des TTS et VC diversifiées pour augmenter les données d'entraînement de RAP. Contrairement à la génération naïve des données TTS/VC, nous avons examiné indépendamment différentes approches telles que les méthodes de sélection des phrases et l'augmentation de la diversité des locuteurs, la durée des phonèmes et les contours de hauteur, en plus d'augmenter systématiquement les conditions environnementales des données générées. Nos résultats montrent que l'augmentation TTS/VC est prometteuse pour augmenter les performances de RAP dans les régimes de données faibles et moyen. En conclusion, nos expériences fournissent un aperçu des variabilités particulièrement importantes pour la RAP et révèlent une approche systématique de l'augmentation des données de RAP utilisant des données synthétiques<br>In the last two decades, the error rate of automatic speech recognition (ASR) systems has drastically dropped, making them more useful in real-world applications. This improvement can be attributed to several factors including new architectures using deep learning techniques, new training algorithms, large and diverse training datasets, and data augmentation. In particular, the large-scale training datasets have been pivotal to learning robust speech representations for ASR. Their large size allows them to effectively cover the inherent diversity in speech, in terms of speaker voice, speaking rate, pitch, reverberation, and noise. However, the size and diversity of datasets typically found in high-resourced languages are not available in medium- and low-resourced languages and in domains with specialised vocabulary like the medical domain. Therefore, the popular method to increase dataset diversity is through data augmentation. With the recent increase in the naturalness and quality of synthetic data that can be generated by text-to-speech (TTS) and voice conversion (VC) systems, these systems have also become viable options for ASR data augmentation. However, several problems limit their application. First, TTS/VC systems require high-quality speech data for training. Hence, we develop a method of dataset curation from an ASR-designed corpus for training a TTS system. This method leverages the increasing accuracy of deep-learning-based, non-intrusive quality estimators to filter high-quality samples. We explore filtering the ASR dataset at different thresholds to balance the size of the dataset, number of speakers, and quality. With this method, we create a high-quality multi-speaker dataset which is comparable to LibriTTS in quality. Second, the data generation process needs to be controllable to generate diverse TTS/VC data with specific attributes. Previous TTS/VC systems either condition the system on the speaker embedding alone or use discriminative models to learn the speech variabilities. In our approach, we design an improved flow-based architecture that learns the distribution of different speech variables. We find that our modifications significantly increase the diversity and naturalness of the generated utterances over a GlowTTS baseline, while being controllable. Lastly, we evaluated the significance of generating diverse TTS and VC data for augmenting ASR training data. As opposed to naively generating the TTS/VC data, we independently examined different approaches such as sentence selection methods and increasing the diversity of speakers, phoneme duration, and pitch contours, in addition to systematically increasing the environmental conditions of the generated data. Our results show that TTS/VC augmentation holds promise in increasing ASR performance in low- and medium-data regimes. In conclusion, our experiments provide insight into the variabilities that are particularly important for ASR, and reveal a systematic approach to ASR data augmentation using synthetic data
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Kandiah, Pakeerathan. "Characterisation and molecular mapping of leaf rust and stripe rust resistance in wheat." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/16915.
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This investigation was carried out for the characterisation and chromosomal locations of resistance to rust diseases in common wheat and durum wheat recombinant inbred line (RIL) populations. A new seedling stripe rust resistance gene (tentatively named YrAW10) was identified in common wheat landrace Aus27696. This gene is effective against both pre-2002 and post-2002 Australian Puccinia striiformis f. sp. tritici (Pst) pathotypes. YrAW10 was located in 3BL-A02-FL-0.22 deletion bin of chromosome 3B and was flanked by SNP markers KASP_13376 and KASP_8775. Yr29/Lr46-linked marker SNPLr46G22 indicated the presence of this gene in Aus27696. The presence of Lr16 was confirmed on the basis of infection type produced by Aus91433 and controls (Thatcher + Lr16 and Exchange) against Puccinia triticina (Pt) pathotype 104-1,3,4,6,7,8,9,10,12+Lr37 and linked marker location in the short arm of chromosome 2B. Lr16 was not effective against the Pt pathotypes used in field study. Genotype C16.14 was proved to carry at least two adult plant resistance (APR) genes located on chromosomes 1D and 3B through iSelect 90K SNP based selective genotyping of C16.14/Aus91433 RILs. The chromosome 3B located resistance was proved to be Lr74 through genotyping of markers closely linked with this gene. In addition to Yr29/Lr46, two other consistent QTL for stripe resistance were detected in Arrivato/Bansi RIL population through DArTseq mapping. QYr.sun-1BS.1 corresponded to Yr24 and QYr.sun-1BS.2 was temporarily named YrAr. Both of these genes produced intermediate responses when present alone. Two QTL located on different linkage groups of chromosome 2B were identified in addition to Lr46/Yr29. QLr.sun-2B.1 appeared to be either a new gene or an allele of Lr16. Aus27506 was shown to carry QLr.sun-2D in addition to Lr46 and QLr.sun-2B was contributed by Aus27229 in Aus27506/Aus27229 population. QLr.sun-2D and QLr.sun-2B appears to be new loci. Comparison of chitin accumulation in the flag leaves with the performance of QTL indicated that combination of two QTL prevent the fungal growth resulting in low disease severity.
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Musaoglu, Orhan. "Effect Of Reinforcement And Pre-stressing Force On Asr Expansion." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614872/index.pdf.
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Alkali Silica Reaction in concrete is a chemical deterioration process occurring between alkalis in cement paste and reactive aggregates. ASR increases expansion and cracking as well as other durability problems such as freezing and thawing. It is most probable that concrete structure will collapse unless mechanical, mineral, or chemical preventive measures are taken against ASR or this problem is realized and solved in the design stage of the concrete structure or later on.
Rather than ordinary preventive measures in which mineral admixtures are used, mechanical ones were investigated in this study. In the experiment done by using the accelerated mortar bar method, reinforced concrete specimens on which pre-stressing force was applied were examined. The effects of reinforcement ratio and pre-stressing force on ASR based expansion and cracking were studied. Expansion and cracking developments in time were followed, and the connection between these phenomena and the energy produced by ASR was made. By applying the same mechanical preventive measures on the specimens prepared by using different reactive aggregates, the effectiveness of these methods with respect to the degree of
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ASR was investigated. Also, the methods in question were compared with traditional preventive measures (fly ash).
The investigation results show that reinforcement and pre-stressing force play a significant role in diminishing the effects of ASR.Keywords:Alkali-Silica Reaction, Reinforced Concrete Specimen, Pre-stressed Concrete, Mechanical Preventive Measures, Energy of ASR
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Zhu, Yufeng. "Assessing Condition on Alkali-Silica Reaction (ASR) Affected Recycled Concrete." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41191.
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Many highway and hydraulic structures in North America have been reported to be affected by alkali aggregate reaction (ASR). It is anticipated that most of these structures will be demolished as they approach the end of their service lives. Recycling demolished concrete as aggregates in new concrete is an option that not only reduces the amount of construction demolition waste (CDW) disposed in landfills but also lessens the consumption of non-renewable resources such as natural aggregates. However, the use of recycled concrete aggregate (RCA) in new concrete requires detailed research to make sure that the durability of the recycled material is not compromised, especially if the RCA had been previously affected by ASR. In this research project, coarse recycled concrete aggregate (RCA) is reclaimed and processed from distinct members (i.e. foundation blocks, bridge deck and columns) of an ASR-affected overpass after nearly 50 years of service. RCA concrete mixtures incorporating 50 and 100% replacement are manufactured and stored in conditions enabling further ASR development. Mechanical (i.e. Stiffness Damage Test - SDT) and microscopic (Damage Rating Index - DRI) analyses are performed at a fixed “secondary” induced expansion of 0.12%. Results show that the overall performance of the ASR-affected recycled mixtures depends upon the “past” condition of the RCA particles. Moreover, the DRI was able to capture the “past” and “secondary” induced expansion and damage of affected RCA while the SDT only detected the “secondary” distress development. Lastly, an adapted version of the DRI was proposed to further evaluate the overall damage of recycled concrete along with properly displaying “past” and “secondary” induced distress.
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Hartmann, William. "ASR-Driven Binary Mask Estimation for Robust Automatic Speech Recognition." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1338244649.
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Brown, Christopher J. "Planning decision framework for brackish water aquifer, storage and recovery (ASR) projects." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0013031.
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Lesnicki, Krzysztof Jacek. "Nonlinear resonance methods for assessing ASR susceptibility during concrete prism testing (CPT)." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41054.
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This research focuses on the characterization of damage accumulation in concrete specimens. Specifically, a nonlinear vibration technique is used to characterize the damage introduced by ongoing alkali-silica reactions (ASR). The nonlinear resonance testing consists of an analysis of the frequency response of concrete specimens subjected to impact loading. ASR introduces a third gel like phase, which can be expansive in the presence of moisture. The result of ASR is the formation of microcracks and debonding between aggregate and cement phases. Collectively, these changes act to increase the specimens' nonlinearity. As a result, it is found that the concrete samples exhibit nonlinear behavior; mainly a decrease in resonance frequency with an increasing level of excitation strain. The relationship between the amplitude of the response and the amount of frequency shift is used as a parameter to describe the nonlinearity of the specimen. The specimens used in this research are of varying reactivity with respect to ASR, which is induced in accordance with ASTM C 1293. The level of nonlinearity is used as a measure of damage caused by the progress of ASR throughout the one year test duration. These nonlinear resonance results are compared to the traditional measures of expansion described in the standard. The robustness and repeatability of the proposed technique is also investigated by repeated testing of samples assumed to be at a specific damage state. Finally, a petrographic staining technique is used to complement nonlinearity measurements and to further gain understanding of ASR. The results of this study show that the proposed nonlinear resonance methods are very sensitive to microstructural changes and have great potential for quantitative damage assessment in concrete.
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Hahn, Stefan [Verfasser]. "Monotone string-to-string translation for NLU and ASR tasks / Stefan Hahn." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2015. http://d-nb.info/1076065139/34.
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Soundarapandian, Senthil. "Evaluation of lithium based deicing chemicals for mitigating ASR in concrete pavement." Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1202410176/.
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Keerio, Ayaz. "Acoustic analysis of Sindhi speech : a pre-curser for an ASR system." Thesis, University of Sussex, 2011. http://sro.sussex.ac.uk/id/eprint/6325/.
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The functional and formative properties of speech sounds are usually referred to as acoustic-phonetics in linguistics. This research aims to demonstrate acoustic-phonetic features of the elemental sounds of Sindhi, which is a branch of the Indo-European family of languages mainly spoken in the Sindh province of Pakistan and in some parts of India. In addition to the available articulatory-phonetic knowledge; acoustic-phonetic knowledge has been classified for the identification and classification of Sindhi language sounds. Determining the acoustic features of the language sounds helps to bring together the sounds with similar acoustic characteristics under the name of one natural class of meaningful phonemes. The obtained acoustic features and corresponding statistical results for a particular natural class of phonemes provides a clear understanding of the meaningful phonemes of Sindhi and it also helps to eliminate redundant sounds present in the inventory. At present Sindhi includes nine redundant, three interchanging, three substituting, and three confused pairs of consonant sounds. Some of the unique acoustic-phonetic features of Sindhi highlighted in this study are determining the acoustic features of the large number of the contrastive voiced implosives of Sindhi and the acoustic impact of the language flexibility in terms of the insertion and digestion of the short vowels in the utterance. In addition to this the issue of the presence of the affricate class of sounds and the diphthongs in Sindhi is addressed. The compilation of the meaningful language phoneme set by learning their acoustic-phonetic features serves one of the major goals of this study; because twelve such sounds of Sindhi are studied that are not yet part of the language alphabet. The main acoustic features learned for the phonological structures of Sindhi are the fundamental frequency, formants, and the duration — along with the analysis of the obtained acoustic waveforms, the formant tracks and the computer generated spectrograms. The impetus for doing such research comes from the fact that detailed knowledge of the sound characteristics of the language-elements has a broad variety of applications — from developing accurate synthetic speech production systems to modeling robust speaker-independent speech recognizers. The major research achievements and contributions this study provides in the field include the compilation and classification of the elemental sounds of Sindhi. Comprehensive measurement of the acoustic features of the language sounds; suitable to be incorporated into the design of a Sindhi ASR system. Understanding of the dialect specific acoustic variation of the elemental sounds of Sindhi. A speech database comprising the voice samples of the native Sindhi speakers. Identification of the language‘s redundant, substituting and interchanging pairs of sounds. Identification of the language‘s sounds that can potentially lead to the segmentation and recognition errors for a Sindhi ASR system design. The research achievements of this study create the fundamental building blocks for future work to design a state-of-the-art prototype, which is: gender and environment independent, continuous and conversational ASR system for Sindhi.
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Zhang, Chi. "Microstructural characterization and modeling of concrete damaged by Alkali-Silica Reaction (ASR)." Doctoral thesis, Université Laval, 2017. http://hdl.handle.net/20.500.11794/27827.
Full textAbstract:
La réaction alcalis-silice (RAS) est un des principaux mécanismes nuisibles affectant la durabilité du béton. Le programme de recherche effectué dans le cadre de ce doctorat comprend deux parties (3 phases), soit la caractérisation microstructurale de produits de la RAS et la modélisation du mécanisme d’endommagement du béton par la RAS. Les résultats expérimentaux de cette recherche fourniront de nouvelles données sur les propriétés microstructurales de bétons affectés par la RAS. Les travaux effectués lors de la première phase du programme expérimental avaient pour objectif de caractériser les propriétés micromécaniques des produits de la RAS à l’aide de nouvelles techniques de nano- et micro-indentation, avec emphase portée sur leur propriété en viscosité. Les échantillons de béton utilisés lors du programme d’essais ont été extraits d’un pavage en béton fortement affecté par la RAS et situé dans la région de Bécancour (Québec). Le béton est caractérisé par de nombreuses particules de granulats de calcaire à grains fins contenant des microfissures remplies de produits secondaires de RAS; les fissures s’étendent dans la pâte de ciment pour former un réseau se propageant de particule en particule. Après une préparation soigneuse de l’échantillon par polissage, la surface des particules de granulats et des veinules apparaissant dans ces particules (i.e. microfissures remplies de produits cristallins de réaction) ont été examinées par Atomic Force Microscopy (AFM) avant de procéder aux essais de nano-indentation. Des valeurs de module et de dureté ont été mesurées pour les produits de réaction par micro- et nano-indentation. Les résultats de ces essais indiquent que les produits cristallins de RAS offrent un comportement de relaxation important atteignant environ 40%. De plus, un modèle rhéologique simplifié est proposé permettant de reproduire les courbes de relaxation sous charge et les valeurs asymptotiques. Ces résultats suggèrent que la relaxation des produits de RAS est importante et principalement irréversible. Les travaux de la deuxième phase du programme expérimental ont permis d’explorer l’utilisation d’une nouvelle technique de microscratch afin de caractériser l’énergie de fracturation (i.e. rigidité) des particules de granulats réactifs de type calcaire dans un béton fortement affecté par la RAS (viaduc routier de la région de Québec). Les particules de granulats montraient typiquement un zonage (zones gris-foncées et gris-pâles) entourant des veinules blanchâtres au sein des particules réactives. En tant que référence, un échantillon de calcaire vierge provenant d’une carrière de la région de Québec a été sélectionné et soumis aux mêmes procédures d’essais. En plus des propriétés élastiques, la rigidité des particules de granulats réactives ont été mesurées statistiquement et se situe autour de 1.5 MPam1/2. La rigidité de fracturation des particules de granulats réactives a démontré n’être affecté ni par la direction d’essai par rapport au plan de litage, ni par la zonation qui a d’abord été interprétée comme des portions montrant des signes de réaction. Ainsi, l’endommagement des particules de granulats semble se situer presqu’essentiellement au niveau des microfissures générées dans les particules réactives. La dernière phase du programme expérimental s’est concentrée sur la caractérisation des propriétés en fluage et en relaxation des produits cristallins de RAS remplissant les microfissures des granulats calcaire réactifs (échantillons provenant du pavage fortement affecté par la RAS utilisés lors de la première phase du programme expérimental). Les essais de micro-indentation ont été réalisés sous deux conditions d’humidité relative. Il a été observé qu’une augmentation en humidité relative réduisait fortement la déformation de fluage irréversible des produits cristallins de RAS, qui montrent un temps caractéristique plus grand. Ainsi, la teneur en eau semble favoriser le mécanisme de glissement irréversible le long ou entre les plaquettes des produits cristallins (rosettes lamellaires) de RAS sous charge constante. Finalement, les implications des résultats de ces travaux sont discutées en lien avec le processus de génération de pression à l’intérieur des particules de granulats réactives. Les propriétés rhéologiques des produits de RAS peuvent jouer un rôle critique lors du relâchement des contraintes internes induites par l’expansion de ces produits. Enfin, un modèle simplifié « 1D » est proposé comme nouvel outil de recherche, et ce afin de prendre en compte les principaux résultats de cette étude, i.e. les propriétés visco-élastiques des produits de RAS et les propriétés de rigidité des particules de granulats réactives.<br>The Alkali-Silica Reaction (ASR) is one main detrimental factor to affect the durability of concrete. The research comprises two parts, i.e. microstructural characterization of ASR products (3 phases), and modeling of concrete damage due to ASR. The experimental results will provide new findings on the microstructure properties of ASR-damaged concrete. The work in the first phase of the research aims at characterizing the micromechanical properties of ASR products by new techniques of nanoindentation and micro-indentation, with emphasis on their viscous behavior. The concrete samples were extracted from a heavily ASR-affected concrete pavement in Bécancour (Québec). The concrete is characterized by numerous fine-grained limestone aggregate particles with microcracks filled with secondary reaction products that extend into the cement into a network from one aggregate particle to another. After careful sample preparation (polishing), the surface of the aggregate particle and of the veinlets (i.e. cracks filled with crystalline ASR product within the aggregate particles) was examined by Atomic Force Microscopy (AFM) before nanoindentation testing. Both nanoscale and microscale indentation modulus and hardness of ASR products were measured. The test results show that ASR crystalline products exhibit important relaxation behavior of about 40%. Then, a simplified rheological model was proposed to fit the load relaxation curves and their asymptotic values. These results suggest that ASR product relaxation is significant and mostly irreversible. The second research phase explored the use of the novel micro-scratch technique to characterize the fracture energy (i.e., toughness) of the ASR-affected limestone aggregate particles within a core specimen extracted from a heavily ASR-affected concrete bridge from the Québec City area. The ASR-affected aggregate particles were typically showing “zoning” (i.e. light grey and dark grey) surrounding white veinlets within reacted limestone aggregate particles. As a reference, an undamaged/virgin quarried limestone specimen from a local quarry was selected and subjected to similar testing. Besides the elastic properties, the toughness of the reactive aggregate particles was statistically measured to be around 1.5 MPam1/2. The fracture toughness of reactive aggregate particles was affected neither by the bedding line directions nor by the “zoning” that was first thought to correspond to “reacted” portions of the particles. Besides the major cracks filled by ASR products, the results indicated that the surrounding reactive aggregate was not characterized by any significant internal damage distribution. In the later phase of the experimental program, our research focused on characterizing the creep and stress relaxation properties of the ASR crystalline products typically filling microcracks within reactive limestone particles (specimen from the heavily ASR-affected concrete pavements in Bécancour (Québec) used in phase 1). The testing carried out was micro-indentation under controlled relative humidity. It was found that an increase in relative humidity strongly reduces the irreversible creep deformation of ASR crystalline products, which act a greater characteristic time. That is, the water content seems to favor irreversible sliding mechanisms along/between the ASR crystals under constant load. Finally, the implications the research findings are discussed with respect to the stress build-up process within reactive aggregate particles. The rheological property of ASR products may play a critical role to releasing the internal stress induced by the ASR product expansion. Finally, a “1D thought model” is proposed as a new research avenue to account for the major results of this work into ASR-damaged concrete modeling, i.e., the visco-elastic property of ASR products and the damage toughness of reactive aggregates.
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Tjalve, Michael. "Accent features and idiodictionaries : on improving accuracy for accented speakers in ASR." Thesis, University College London (University of London), 2007. http://discovery.ucl.ac.uk/1445873/.
Full textAbstract:
One of the most widespread approaches to dealing with the problem of accent variation in ASR has been to choose the most appropriate pronunciation dictionary for the speaker from a predefined set of dictionaries. This approach is weak in two ways: firstly that accent types are more numerous and more variable than can be captured in a few dictionaries, even if the knowledge were available to create them and secondly, accents vary in the composition and phonotactics of the phone inventory not just in which phones are used in which word.;In this work, we identify not the speaker's accent, but accent features which allow us to predict by rule their likely pronunciation of all words in the dictionary. Any given speaker is associated with a set of accent features, but it is not a requirement that those features constitute a known accent. We show that by building a pronunciation dictionary for an individual, an idiodictionary, recognition accuracy can be improved over a system using standard accent dictionaries.;The idiodictionary approach could be further enhanced by extending the set of phone models to improve the modelling of phone inventory and variation across accents. However an extended phoneme set is difficult to build since it requires specially-labelled training material, where the labelling is sensitive to the speaker's accent. An alternative is to borrow phone models of a suitable quality from other languages. In this work, we show that this phonetic fusion of languages can improve the recognition accuracy of the speech of an unknown accent.;This work has practical application in the construction of speech recognition systems that adapt to speakers' accents. Since it demonstrates the advantages of treating speakers as individuals rather than just as members of a group, the work also has potential implications for how accents are studied in phonetic research generally.
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Santini, Alessandro <1983>. "Industrial ecology applied to ELV management. Material and energy recovery from ASR." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4496/1/santini_alessandro_tesi.pdf.
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This PhD thesis reports on car fluff management, recycling and recovery. Car fluff is the residual waste produced by car recycling operations, particularly from hulk shredding. Car fluff is known also as Automotive Shredder Residue (ASR) and it is made of plastics, rubbers, textiles, metals and other materials, and it is very heterogeneous both in its composition and in its particle size. In fact, fines may amount to about 50%, making difficult to sort out recyclable materials or exploit ASR heat value by energy recovery.
This 3 years long study started with the definition of the Italian End-of-Life Vehicles (ELVs) recycling state of the art. A national recycling trial revealed Italian recycling rate to be around 81% in 2008, while European Community recycling target are set to 85% by 2015. Consequently, according to Industrial Ecology framework, a life cycle assessment (LCA) has been conducted revealing that sorting and recycling polymers and metals contained in car fluff, followed by recovering residual energy, is the route which has the best environmental perspective.
This results led the second year investigation that involved pyrolysis trials on pretreated ASR fractions aimed at investigating which processes could be suitable for an industrial scale ASR treatment plant. Sieving followed by floatation reported good result in thermochemical conversion of polymers with polyolefins giving excellent conversion rate. This factor triggered ecodesign considerations. Ecodesign, together with LCA, is one of the Industrial Ecology pillars and it consists of design for recycling and design for disassembly, both aimed at the improvement of car components dismantling speed and the substitution of non recyclable material.
Finally, during the last year, innovative plants and technologies for metals recovery from car fluff have been visited and tested worldwide in order to design a new car fluff treatment plant aimed at ASR energy and material recovery.
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Santini, Alessandro <1983>. "Industrial ecology applied to ELV management. Material and energy recovery from ASR." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4496/.
Full textAbstract:
This PhD thesis reports on car fluff management, recycling and recovery. Car fluff is the residual waste produced by car recycling operations, particularly from hulk shredding. Car fluff is known also as Automotive Shredder Residue (ASR) and it is made of plastics, rubbers, textiles, metals and other materials, and it is very heterogeneous both in its composition and in its particle size. In fact, fines may amount to about 50%, making difficult to sort out recyclable materials or exploit ASR heat value by energy recovery.
This 3 years long study started with the definition of the Italian End-of-Life Vehicles (ELVs) recycling state of the art. A national recycling trial revealed Italian recycling rate to be around 81% in 2008, while European Community recycling target are set to 85% by 2015. Consequently, according to Industrial Ecology framework, a life cycle assessment (LCA) has been conducted revealing that sorting and recycling polymers and metals contained in car fluff, followed by recovering residual energy, is the route which has the best environmental perspective.
This results led the second year investigation that involved pyrolysis trials on pretreated ASR fractions aimed at investigating which processes could be suitable for an industrial scale ASR treatment plant. Sieving followed by floatation reported good result in thermochemical conversion of polymers with polyolefins giving excellent conversion rate. This factor triggered ecodesign considerations. Ecodesign, together with LCA, is one of the Industrial Ecology pillars and it consists of design for recycling and design for disassembly, both aimed at the improvement of car components dismantling speed and the substitution of non recyclable material.
Finally, during the last year, innovative plants and technologies for metals recovery from car fluff have been visited and tested worldwide in order to design a new car fluff treatment plant aimed at ASR energy and material recovery.
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Carrive, Laetitia. "Considérations sur l’histoire naturelle des Ranunculales." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS177/document.
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Les Ranunculales sont un ordre d’angiospermes d’environ 4500 espèces, incluant des plantes communes comme les boutons d’or et les coquelicots. Leurs fleurs sont très diversifiées et ont piqué l’intérêt des botanistes depuis des décennies. Les sept familles de l’ordre sont faciles à reconnaître sur le terrain, mais paradoxalement, certaines familles n’ont pas de synapomorphies et ont des états ancestraux peu clairs, comme les Ranunculaceae (~ 2500 espèces). Cette diversité florale peut être liée à la pollinisation et des innovations ont pu être guidées par cette interaction. De plus, les plantes de ce groupe produisent une grande variété de composés secondaires, certains dont les propriétés sont connues depuis fort longtemps (comme la morphine et le curare). Ces substances pourraient jouer un rôle dans la défense contre les herbivores. Les caractères floraux et chimiques sont donc de bons candidats pour produire des hypothèses adaptatives. Ici nous utilisons des méthodes analytiques modernes pour comprendre les patrons d’évolution expliquant la distribution actuelle de la diversité et l’évolution des fleurs et des toxines de Ranunculales. Un nouveau cadre phylogénétique synthétique a été produit avec des séquences publiées de 144 espèces. Seize caractères floraux et la présence de certains composés métaboliques ont été reconstruits sur cet arbre avec la méthode de parcimonie et la méthode de « Reversible Jump Monte Carlo Markov Chains ». Un nouveau scénario d’évolution florale a été produit, où les Ranunculales avaient une fleur ancestrale trimère avec trois cycles de tépales et où les ancêtres des familles ont évolué en perdant ou en différenciant des cycles du périanthe. Les patrons d’évolution des toxines montrent de la variabilité, certaines apparaissant et disparaissant aléatoirement (comme les saponines), d’autres étant des synapomorphies bien soutenues de certains clades (comme les diterpènes de type aconitine pour la tribu des Delphinieae). Ces résultats offrent une meilleure compréhension de l’histoire naturelle des Ranunculales. En outre, cet ordre est le groupe-frère de toutes les autres eudicotylédones, et a donc une position clef pour comprendre l’évolution précoce de ce clade. Ces résultats vont fournir une compréhension plus profonde des changements floraux et phytochimiques qui ont eu lieu à la base des eudicotylédones, qui contiennent 70% des angiospermes actuelles<br>Ranunculales are an order of angiosperms comprising ca. 4,500 species including common plants like buttercups and poppies. Their flowers are highly diversified and have raised the interest of botanists for decades. Each of the seven families of the order is easily recognizable in the field, but paradoxically some families lack floral synapomorphies and have unclear ancestral states, like Ranunculaceae (ca. 2,500 species). This floral diversity may be linked to pollination and innovations may have been driven by this interaction. In addition, the plants of this group produce a variety of secondary compounds, some of which having been known for ages for their properties, like morphine or curare. Those substances could play a role in defense against herbivores. Both floral and chemical characters are thus good candidates to produce adaptive hypotheses. Here we used modern analytical methods to understand the the evolutionary patterns accounting for the extant distribution of diversity and evolution of Ranunculales flowers and toxins. A new synthetic phylogenetic framework of the Ranunculales based on already available sequences of 144 species was produced. Sixteen characters of the flower, and the presence of selected secondary metabolites were reconstructed on this tree using parsimony, and Reversible Jump Monte Carlo Markov Chains. A new scenario for floral evolution was produced, where Ranunculales had a trimerous perianth with three whorls of tepals ancestor, and the ancestors of the families evolved by losing and/or differentiating perianth whorls. The evolutionary patterns of toxins showed variability, some appearing and disappearing randomly (such as saponins), others being well-supported synapomorphies (such as aconitine-like diterpens for the tribe Delphinieae). These results offer a better understanding of the natural history of Ranunculales. Furthermore, this order is the sister-group of all other eudicots, and thus has a key position to understand the early evolution of this clade. These results will provide a deeper understanding of the floral and chemical changes that took place at the base of eudicots, which contains 70% of living angiosperms
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Ahmed, Hesham. "Condition Assessment and Analytical Modeling of Alkali-Silica Reaction (ASR) Affected Concrete Columns." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42680.
Full textAbstract:
Concrete has proven to be, by far, one of the most reliable materials for the construction of critical infrastructure. However, despite its structural capacity, concrete members are susceptible to damage mechanisms that may decrease its performance and durability throughout its service life. One such mechanism is alkali-silica reaction (ASR), which takes place when unstable siliceous phases present in coarse or fine aggregates react with the alkali hydroxides from the concrete pore solution, generating a secondary product (i.e., ASR gel); this product swells upon moisture uptake from the surrounding environment, leading to cracking and expansion of the affected concrete. In severe cases of ASR-affected infrastructure, structural safety could become a problem, and thus requiring the demolition of affected members. It is, therefore, necessary to adopt effective protocols for the diagnosis and prognosis of aging infrastructure, to ensure its performance over time along with properly planning for rehabilitation strategies, whether required. This work presents a two-stage case study of the S.I.T.E. building at the University of Ottawa for the diagnosis and prognosis of ASR-affected members (i.e., columns) after nearly 20 years in service. The diagnosis phase was conducted with the aim of evaluating the cause and extent of distress and interpreting its impact on the performance of the affected structure. First, a visual inspection was conducted to evaluate potentially damaged members, in order to select the best location for core-drilling. Once ASR was confirmed through petrographic examination, specimens were evaluated through the multi-level assessment (i.e., coupling of microscopic and mechanical assessment). A range of damage was discovered among the examined columns (i.e., 0.03%, 0.05%, and 0.08% expansion). Moreover, evidence of developing freeze and thaw (FT) damage was discovered in columns with greater levels of expansion, raising future concerns regarding the durability and serviceability of members affected by this coupling of damage (i.e., ASR+FT). For the second stage of this project (i.e., prognosis), a novel ASR semi-empirical model was developed with the aim of predicting future ASR-induced expansion and damage in the S.I.T.E. building. The above model was developed and validated (using ASR exposure site data) through the coupling of existing chemo-mechanical macro-models, which were used to predict material behaviour on the structural scale, and novel mathematical relationships for the prediction of anisotropy in the columns. Moreover, the use of the multi-level assessment to predict the mechanical implications of predicted distress was found to enhance the model’s capacity for prognosis and demonstrated important potential for the accurate prediction of multi-level damage in the S.I.T.E. columns.
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Pham, Keikiet, and Murtazah Khalil. "AKR:s inverkan på betongkonstruktioners bärförmåga." Thesis, KTH, Byggteknik och design, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-102024.
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Alkali-kiselsyrareaktionen (AKR) är en kemisk reaktion som medför att spänningar uppstår i betongen då den bildade silikatgelen expanderar. Reaktionen kräver tillräcklig hög alkalihalt, reaktiv ballast samt vatten. På grund av de AKR-inducerade spänningarna är det av intresse att få kunskap i hur reaktionen påverkar betongens böjmomentkapacitet, förankring samt skjuvnings- och genomstansningskapacitet. För att besvara frågeställningen har därför en omfattande litteraturinventering tillsammans med tre kompletterande intervjuer utförts. Resultat som har erhållits, påvisar att två huvudsakliga effekter fås av AKR. Utöver en reducerad hållfasthet på grund av expansioner och sprickbildningar, erhålls även en gynnsam förspänningseffekt när armering motverkar expansioner. Med hänsyn till dessa huvudeffekter påverkas betongs bärighet i olika stor utsträckning beroende på expansionens storlek samt armeringens läge och typ i tvärsnittet. Resultaten tyder på att draghållfastheten reduceras till 40 % medan tryckhållfastheten reduceras till 60 % vid 5 mm/m expansion. För böjkapaciteten har ingen större reduktion uppmäts då expansioner understiger 6 mm/m. Emellertid har en reduktion på 25 % observerats vid expansioner större än 6 mm/m. Skjuvkapaciteten i AKR-skadad betong beror till stor del av byglars närvaro samt expansionens omfattning. I balkar utan byglar reduceras skjuvkapaciteten med 15-25 % för slät armering och 20-30 % för räfflad armering. Genomstansningskapaciteten i ett dubbelarmerat betongtvärsnitt reduceras obetydande till dess att expansionen överstiger 6 mm/m varpå en mer påtaglig reduktion fås. Hållfastheten för vidhäftning minskar med ca 40 % då täckande betongskikt understiger 1.5Æ och/eller att inga byglar är närvarande. Om byglar är närvarande samt om täckande betongskikt överstiger 4Æ visas inga tecken på försämrad vidhäftningshållfasthet. Utöver en minskad bärighet, öppnar AKR upp betong och skapar gynnsammare förutsättningar för rost-och frostangrepp.<br>Alkali-silica reaction (ASR) is a chemical reaction that causes stresses in concrete when the produced alkali silica gel expands. The reaction requires sufficiently high alkali content, reactive aggregates and water. Due to ASR-induced stresses it is of interest to gain insight in how ASR affects the concrete’s bending capacity, anchoring together with shear- and punching shear capacity. An extensive literature review was therefore carried out together with three complementary interviews in order to answer the question at issue. Obtained results show two main effects of ASR. In addition to a reduced strength because of cracking and expansion, an advantageous pre-stress is gained due to restraint to expansion. Thus, the load-carrying capacity of concrete is affected in various extents depending on the size of expansion and location and type of the reinforcement. The results indicate that the tensile strength is reduced to 40 % whereas the compressive strength is reduced to 60 % at 5 mm/m expansions. While expansions lesser than 6 mm/m has not shown a greater reduction of the bending capacity, a reduction of 25 % has been observed in concrete with expansions greater than 6 mm/m. The shear capacity of an ASR-affected concrete structure depends mainly on the presence of links and the extent of expansions. In beams without links, shear capacity is reduced to 15-25 % for smooth bars and 20-30 % for ribbed bars. The punching strength of a concrete structure reinforced in both faces is not reduced until expansions exceed 6 mm/m, whereas a more significant reduction is obtained. The bond strength decreases by about 40 % if the concrete cover is less than 1.5 Æ and/or if no links are present. Meanwhile if links are present and if concrete cover is more than 4Æ, no signs of reduction of the bond strength has been observed. Additionally, to a reduced load-carrying capacity, ASR also opens up the concrete and consequently creates beneficial circumstances for corrosion and frost attacks.
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Garcia, Jennifer N. "A Geochemical Analysis: Application of a Chelating Agent on Potential ASR Reactive Aggregates." Digital Archive @ GSU, 2011. http://digitalarchive.gsu.edu/geosciences_theses/39.
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Alkali Silica Reaction (ASR) is a deleterious, expansive reaction in concrete. Several ASTM methods test potential aggregates for ASR risk. One method uses NaOH digestion, followed by spectroscopic methods, to estimate the amount of reactive silica present in an aggregate. NaOH, however, can digest both crystalline (i.e. quartz) and non-crystalline (e.g. opal), or poorly crystalline silica, potentially yielding falsely high estimates of reactive silica. Studies in soil and plant sciences have used Tiron, an alkaline chelating agent (C6H4S2O8Na2), as a method of digesting opaline silica for spectroscopic analysis. Here we test this approach by analyzing reactive silica in road aggregate. Tiron extraction of reactive silica is more selective, in some cases extracting only ~ 30% of the silica compared to the harsher NaOH extraction: variation is due to differences in aggregate mineralogy, specifically SiO2. In conducting chelation analyses, UV/VIS seems to be a better approach than AA.
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Wright, Timothy Edwin James. "Predicting the applicability of aquifer storage recovery (ASR) in the UK chalk aquifer." Thesis, University College London (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405796.
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Arenhart, Rafael Augusto. "Caracterização funcional dos genes ASR na resposta ao alumínio em arroz (ORYZA SATIVA)." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/143380.
Full textAbstract:
O arroz é considerado o cereal mais tolerante ao alumínio (Al). Entretanto, a variabilidade entre os genótipos leva a uma considerável diferença quanto ao grau de tolerância para cultivares distintas. Diversos estudos mostram que plantas de arroz toleram o Al por intermédio de mecanismos internos e externos. Neste trabalho foi analisada a modulação da expressão da família gênica ASR (Aba, Stress and Ripening) em função do tratamento com Al. O gene ASR5 foi diferencialmente expresso em raízes de arroz tolerante ao Al (ssp Japonica cv Nipponbare). Entretanto, ASR5 não respondeu a exposição ao Al em raízes de arroz sensíveis ao Al (ssp Indica cv Taim). Plantas transgênicas silenciadas para os genes ASR apresentaram um aumento da sensibilidade ao Al. Calos embriogênicos de arroz transformados com a fusão ASR5-GFP revelaram que a proteína ASR5 localiza-se no núcelo e no citoplasma. Em protoplastos transformados, ASR5 localizou-se nos cloroplastos. Usando uma abordagem proteômica, comparando plantas não-transformadas e plantas ASR5_RNAi, um total de 41 proteínas com padrões contrastantes foi identificado. No intuito de identificar genes com expressão alterada pelo Al em arroz, e buscar genes afetados pelo silenciamento de ASR5, foi realizado o sequenciamento total dos transcritos utilizando plantas de arroz não transformadas e ASR5_RNAi em duas condições: controle e tratamento com Al. Essas análises transcriptômicas revelaram que 961 genes responderam ao Al em raízes de plantas de arroz não transgênicas submetidas ao Al. Nas plantas ASR5_RNAi, apenas 309 genes responderam ao tratamento com Al. Entretanto, apenas 52 desses genes se sobrepuseram quando comparados ao grupo de genes modulados em plantas não transformadas, sugerindo que a planta ASR5_RNAi perdeu a capacidade de regular um conjunto de genes. Além disso, análises de imunoprecipitação da cromatina seguida de sequenciamento em massa, revelaram que ASR5 liga-se ao promotor do gene STAR1, entre outros, regulando sua expressão em resposta ao Al. Os resultados mostram pela primeira vez que ASR5 atua como fator de transcrição em arroz e que está envolvido na regulação de genes responsivos ao Al conferindo tolerância frente à toxicidade do Al.<br>Among cereal crops, rice is considered the most aluminium (Al) tolerant species. However, variability among rice genotypes leads to remarkable differences in the degree of Al tolerance for distinct cultivars. A number of studies have demonstrated that rice plants achieve Al tolerance through internal and external mechanisms. We have analyzed expression changes of the rice ASR (Aba, Stress and Ripening) gene family as a function of Al treatment. The gene ASR5 was differentially regulated in the Al-tolerant rice ssp Japonica cv Nipponbare. However, ASR5 expression did not respond to Al exposure in Indica cv Taim rice roots, which are highly Al-sensitive. Transgenic plants carrying RNAi constructs that targeted the ASR genes displayed increased Al susceptibility in T1 plants. Rice embryogenic calli expressing an ASR5-GFP fusion revealed that ASR5 was localized in both the nucleus and cytoplasm. In transformed protoplasts, ASR5-GFP appears in chloroplast cells. Using a proteomic approach to compare non-transformed and ASR5_RNAi plants, a total of 41 proteins with contrasting expression patterns were identified. In order to identify genes with differential modulation under Al stress in rice, and search for genes affected by ASR5 silencing, RNA-seq was made in non-transformed plants and ASR5_RNAi plants in control conditions and after Al treatment. These analyses revealed that 961 genes responded to Al in non-transformed rice roots under Al stress. A total of 309 genes responded to Al in ASR5_RNAi plants. Only 52 genes overlapped between non transformed and ASR5_RNAi plants when comparing genes modulated by Al, showing that ASR-silenced plants lost the ability to modulate a set of genes in response to Al treatment. Furthermore, ChIP-Seq analysis revealed that ASR5 can bind to the promoter of STAR1, among other genes, regulating its expression under Al stress. These results show for the first time that ASR5 act as a transcription factor in rice and that it regulates Al-responsive genes conferring tolerance in rice against Al toxicity.
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Matsushita, Hitokazu. "Computerized Oral Proficiency Test for Japanese: Measuring L2 Speaking Ability with ASR Technology." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2691.
Full textAbstract:
Developing a time- and cost-efficient method for second language (L2) oral proficiency measurement is one of the research topics that has attracted much attention in recent decades. The purpose of this study is to develop a computerized oral testing system for L2 Japanese using automatic speech recognition (ASR) technology. Two testing methods called elicited imitation (EI) and simulated speech (SS) are proposed to quantify L2 accuracy and fluency via ASR processing. This study also suggests systematic EI item creation leveraging corpus technology and discusses the effectiveness of the test items created through analyses of item difficulty. Further, refinement of the EI grading system is described through a series of statistical investigations. For SS, this study reports the five most influential L2 fluency features identified through machine learning and proposes a method to yield individual SS scores with these features based on previous studies. Lastly, several methods to combine the EI and SS scores are presented to estimate L2 oral proficiency of Japanese.
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TURRISI, Rosanna. "On Deep Learning strategies to address Automatic Speech Recognition (ASR) for dysarthric speech." Doctoral thesis, Università degli studi di Ferrara, 2021. http://hdl.handle.net/11392/2488127.
Full textAbstract:
This thesis explores deep learning techniques to improve Automatic Speech Recognition (ASR) for people affected by dysarthria. Dysarthria is a widely spread motor disorder causing high speech unintelligibility and, often, also motor control abnormalities. Hence, ASR-based technologies may represent the only possibility for dysarthric individuals to interact with other people or machines. Unfortunately, traditional ASR systems fail in presence of dysarthric speech. For instance, we tested Google Speech API and IBM on a subset of the TORGO dataset. These provide more than 80% of WER, while the human error is 30%. One of the main issues is that the ASR model cannot capture the inter-speaker variability, due to the small and limited dysarthric speech corpora. To overcome this issue, we propose three possible strategies.
Firstly, we investigate the use of speech production knowledge as additional information in the ASR system. As the articulatory features (AFs) are difficult to collect, especially for dysarthric speakers, we move a step backward and first study deep learning based methods to synthesize AFs for audio-only corpora. Specifically, we propose the use of phonetic features in addition or substitution to the acoustic ones in the standard Acoustic Inversion (AI) mapping, with the aim of improving its generalization across datasets. Then, we introduce unsupervised methods to synthesize AFs that leverage phonetic features, to extract raw articulatory information, and acoustic vectors, to capture complex phenomena such as the coarticulation.
We finally integrate the synthetic AFs as secondary target or additional input in the ASR model. After a preliminary study on the TIMIT corpus showing encouraging results on phone classification, we evaluate the ASR performance on CHiME-4.
The first and the second strategies provide a Word Error Rate (WER) relative reduction of 1.9% and 5.4%, respectively, over the traditional ASR system.
Secondly, we consider the scenario in which we have access to multiple labelled datasets (sources) and we want to learn a classifier for an unlabelled dataset (target). Such a problem is known in machine learning as multi-source domain adaptation. We propose an algorithm, named Multi-Source Domain Adaptation via Weighted Joint Optimal Transport (MSDA-WDJOT), that aims at finding simultaneously an Optimal Transport-based alignment between the source and target distributions and a re-weighting of the sources distributions, based on their similarity with the target distribution. We then employ MSDA-WJDOT in two real-world applications: dysarthria detection and spoken command recognition. In the first case, we assume to have multiple labelled noisy datasets containing dysarthric and healthy speech and we adopt MSDA-WJDOT to learn a binary classifier for an unlabelled noisy dataset. The proposed approach outperforms all the competitor models, improving the detection accuracy of 0.9% over the best one. In the second case, MSDA-WJDOT is used to perform dysarthric speaker adaptation in a voice command recognition system. This provides an accuracy relative improving of 21% and 12% over the baseline and the best competitor model, respectively.
Finally, we focus on contexts in which only a small vocabulary
needs to be recognized. This allows to simplify the problem to spoken command recognition. Towards this direction, we collected a dysarthric speech corpus containing commands related to the task of making a call. This is the richest Italian dysarthric speech corpus to date and it can be used to train a Command Recognizer and develop a smartphone Contact application. Last but not least, we introduce the AllSpeak project in which it has been developed an Android application for people affected by Amyotrophic Lateral Sclerosis. Specifically, this App is based on a Voice Command Recognition that recognizes commands related to basic needs even when the speech intelligibility is almost vanished.<br>L'obiettivo di questa tesi è quello di sviluppare tecniche di deep learning per sistemi di riconoscimento vocale (RV) per persone affette da disartria. La disartria è un disordine motorio che comporta una compromissione della comunicazione verbale e difficoltà nel controllo motorio. Perciò, dispositivi basati sul riconoscimento vocale potrebbero rappresentare l'unica possibilità per soggetti disartrici di interagire con il mondo esterno. Tuttavia, le tecnologie oggi disponibili risultano inadeguate. Ad esempio, testando Google Speech API e IBM sul dataset TORGO, abbiamo ottenuto un Word Error Rate (WER) superiore all'80%. Poiché le caratteristiche del parlato dipendono dalla gravità e dal tipo di disartria, un modello di RV ideale dovrebbe essere addestrato su grandi dataset di parlato disartrico. Sfortunatamente, questi dati sono difficili da acquisire e sono oggi disponibili solo pochi e limitati dataset. Al fine di risolvere questo problema, presentiamo qui tre possibili strategie.
La prima strategia si basa sull'integrazione di informazioni sulla dinamica del tratto vocale nei sistemi di RV. Poiché la misurazione articolatoria è piuttosto invasiva e costosa, ci siamo prima soffermati su metodi per la sintesi di feature articolatorie (FA), a partire da feature fonetiche. Più precisamente, proponiamo l'uso delle feature fonetiche in aggiunta o in sostituzione a quelle acustiche nell'Acoustic Inversion (AI) map, con lo scopo di migliorare la generalizzazione a nuovi dataset. Successivamente, abbiamo introdotto metodi non supervisionati che combinano feature fonetiche, contenenti informazioni articolatorie grezze, e feature acustiche, contenenti informazioni sulla co-articolazione, per sintetizzare FA.
Infine, abbiamo esplorato due strategie per integrare le FA sintetizzate nei sistemi di RV. Dopo aver ottenuto incoraggianti risultati sul dataset TIMIT sulla classificazione di fonemi, abbiamo testato le performance del sistema di RV sul dataset CHiME-4. Le due strategie hanno portato a una riduzione relativa del WER di 1.9% e 5.4%, rispettivamente.\\
La seconda strategia si basa sul multi-source domain adaptation (MSDA), in cui vengono sfruttati dataset sorgente per apprendere un classificatore per un dataset target. L'algoritmo proposto, MSDA Weighted Joint Distribution Optimal Transport (MSDA-WJDOT), è ottimizzato per trovare il miglior allineamento, basato sul Trasporto Ottimo, tra la distribuzione di probabilità del target e una combinazione convessa di quelle sorgente. Tale combinazione è pesata da un coefficiente che viene appreso in base alla distanza tra le distribuzioni sorgente e target. Abbiamo utilizzato poi questo algoritmo in due applicazioni. Nel primo caso, abbiamo adottato MSDA-WJDOT per imparare una funzione in grado di diagnosticare la disartria. In questo caso, sia i dataset sorgente che quello target sono dataset di parlato disartrico e normale, contenente ciascuno un diverso tipo di rumore. La seconda applicazione riguarda invece l'adattamento di un sistema di riconoscimento di comandi vocali a uno speaker disartrico. In entrambi i casi, MSDA-WJDOT ha ottenuto performance migliori sia della baseline che di altri metodi per il MSDA.
In ultimo, ci siamo focalizzati su contesti in cui è sufficiente il riconoscimento di un vocabolario limitato. Questo permette di semplificare il problema riducendolo al riconoscimento di comandi vocali. Lavorando in questa direzione, abbiamo acquisito un dataset di parlato disartrico contenente comandi relativi all'uso di un'applicazione Rubrica per smartphone. Queste registrazioni costituiscono il più esteso dataset di parlato disartrico in italiano. Infine, introduciamo il progetto AllSpeak in cui è stata sviluppata un'applicazione Android basata sul riconoscimento di comandi vocali. Questa permette a soggetti affetti da Sclerosi Laterale Amiotrofica (SLA) di comunicare i loro bisogni primari anche quando il loro parlato è a stento intelligibile.
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Millard, Marcus J. "Effects of Lithium Nitrate Admixture on Early Age Concrete Behavior." Thesis, Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11615.
Full textAbstract:
Alkali silica reaction (ASR), a reaction which occurs between reactive siliceous mineral components in the aggregate and the alkaline pore solution in concrete, is responsible for substantial damage to concrete structures in the U. S. and across the world. Lithium admixtures, including lithium nitrate (LiNO3), have been demonstrated to mitigate ASR damage, and are of particular interest for use in concrete airfield pavement construction, where ASR damage has been recently linked to the use of certain de-icing chemicals. Although the effectiveness of lithium admixtures at ASR-mitigation is well-researched, relatively less is known regarding the potential effects, including negative effects, on overall concrete behavior. The goal of this research is to better understand the influence of LiNO3 admixture on early age concrete behavior, and to determine if a maximum dosage rate for its use exists.
Isothermal calorimetry, rheology and bleed water testing, time of setting, chemical shrinkage, autogenous shrinkage, free and restrained concrete shrinkage, and compressive and flexural strength were measured for pastes and concretes prepared with a range of LiNO3 dosages (i.e., 0, 50, 100, 200, and 400% of the recommended dosage). In addition, the interaction of LiNO3 with cement was evaluated by comparing results obtained with six cements of varying alkali and tricalcium aluminate (C3A) contents. Additionally, one of these cements, was examined alone and with 20% by weight Class F fly ash replacement.
Results indicate that the hydration of the tricalcium silicate and tricalcium aluminate components of cement are accelerated by the use of LiNO3, and that low alkali cements (typically specified to avoid damage by ASR) may be particularly susceptible to this acceleration. However, inclusion of Class F fly ash at 20% by weight replacement of cement (also common in applications where ASR is a concern) appears to diminish these possibly negative effects of LiNO3 on early age hydration acceleration and heat generation. Dosages higher than the current standard dosage of LiNO3 may have minor effects on fresh concrete workability, causing slight decreases in Bingham yield stress, corresponding to slightly higher slump. Fresh concrete viscosity may also be affected, though more research is necessary to confirm this effect. LiNO3 had no effect on quantity of bleed water in the mixes tested. Generally, LiNO3 had no effect on initial and final setting times, although increasing dosages caused faster set times in the lowest alkali (Na2Oeq = 0.295%) cement examined. In shrinkage testing, higher LiNO3 dosages appeared to cause initial expansion in some sealed paste specimens, but in all cases the highest dosage led to greater autogenous shrinkage after 40 days. In concrete specimens, however, the restraining effect of aggregates diminished shrinkage, and no effect of the LiNO3 was apparent. In no cases, with any dosage of lithium tested, with or without fly ash replacement, did restrained shrinkage specimens show any cracking. Strength testing produced mixed results, with laboratory specimens increasing in 28-day compressive strength, but companion specimens cast in the field and tested by an outside laboratory, exhibited lower 28-day compressive strength, with increasing lithium dosages. Flexural specimens, also cast in the field and tested by an outside laboratory, appeared to show an increase in 28-day flexural strength with increasing lithium dosages. However, because of the conflicting results when comparing the various strength data, further research is necessary for conclusive evidence of LiNO3 effects on concrete strength.
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Teikari, Michael. "Stenmjölets inverkan i en kall asfaltsmassa hos bearbetbarheten, brytningsprocessen och täckningsgraden." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-61024.
Full textAbstract:
I kallasfalt med hårt basbitumen bryter vattnet ut ur bitumenet och bindemedlet i massan stelnar olika snabbt beroende på vilket stenmaterial asfaltsmassan består av. Om brytningen sker innan utläggning blir massan obearbetbar, målet är att brytningsprocessen ska kunna styras genom att massans brytningsprocess skall vidta när energi tillförs i massan via en vibratorsvält som packar massan. Från tidigare tester är hypotesen att det är stenmjölet som styr brytningsprocessen och bearbetbarheten. Idag är problemet att massan bryter för snabbt och den blir svårbearbetad vid läggning och resultatet blir dåligt. I arbetet undersöks också täckningsgrad och styvhetsmodulen. Arbetet är utfört på NCC:s väglaboratorium i Umeå 4/4 - 15/4 2016. Sex stycken stenmaterial från olika bergtäkter med olika egenskaper testas. Bergtäkterna är belägna från Närke upptill Västerbotten vid namn Dylta, Råsta, Sälgsjön, Stöningsberget, Ljusberget och Supartallen. Fraktion 0-16 mm från en och varje bergtäkt handblandas, två asfaltsprover tillverkas enligt två olika mix- och bedömningsmetoder. Täckningsgrad, bearbetningsegenskaperna och brytningprocessen bedöms och antecknas i en matris. I nästa steg ersätts ordinarie stenmjöl (0-2 mm) med stenmjöl från en bergtäkt med ett tidigare känt bra stenmaterial. Med resterande makadam (2-16 mm) görs samma process om på nytt och resultatet analyseras och jämförs. En asfaltsmassa med stenmjöl från bergtäkten Supartallen och makadam från bergtäkten Stöningsberget visar förbättrade resultat i jämförelse med fraktion 0-16 mm från bergtäkten Stöningsberget och vidare laborationstester görs på denna blandning av stenmaterial. Dessa bergtäkter ligger geografiskt nära varandra, drygt 25 mil, vilket också motiverar till att välja dessa stenmaterial som i framtiden kanske kommer användas fullskaligt. Från dessa blandningar tillverkas asfaltskroppar genom packning med gyratorisk packare och styvhetmodulen testas. I ekonomisk och miljömässig vinning görs ett försök med en restprodukt från stålindustrin. Ett försök utförs med skänkslagg (0-2 mm). Slaggen blandas med stenmaterial från bergtäkten Supartallen där bearbetningen, brytprocessen och täckningsgraden undersöks. Detta är ett inledande försök för att få en fingervisning hur asfaltsmassan beter sig blandat med skänkslagg. Utvärdering av resultaten gjordes med hjälp av en matriser där varje asfaltsblandning ingår. Asfaltsblandningen betygsätts enligt bearbetbarhet, täckningsgrad och brytningskontroll. Skålen analyserades och slutsatser om brytningen kunde dras. Genom sönderdelning av massan kunde observationer göras om hur brytningen av massan har kommit, även täckningsgraden analyseras. Resultaten pekar på att stenmjölet har en betydande roll i täckningsgrad, brytning vid blandning och brytningsprocessen, dock ingen skillnad på styvhetsmodulen. Att enbart stenmjölet ska vara problemet är inte hela sanningen men har som sagt en betydande roll. Just att stenmaterial från Supartallen är så pass bra för beaktas och använda sig av stenmaterial med liknande egenskaper och inte använda stenmaterial med för höga halter SiO2 då det ger dålig täckningsgrad. Att massan bryter för snabbt kan bero på halten bindemedel, vidare laborationer bör göras med halten bindemedel i fokus.<br>In cold asphalt with hard base-bitumen the water breaks out from the bitumen and the binder in the mass solidifies at different rates depending on the containing stone material in the asphalt. If the break occurs before laying the mass becomes unworkable. The intention by this examination is control this process by the mass extraction process should take place when energy is supplied into the mass through a vibrator famine. From previous tests the hypothesis is that the rock flour controls the breaking-process and the workability. Today, the problem is that the mass curing process starts too early and it becomes difficult to manage and work with and the results of the paving are bad. The thesis project also examines coverage and stiffness module, it’s performed on the NCC's road laboratory in Umeå 4/4 - 15/4 in 2016. Six stone materials from different quarries with different properties are tested. Fraction 0-16 mm from each rock quarry are handmixed, two asphalt samples produced by two different mixing- and assessment-methods. Coverage, workability and the breaking-process are assessed and recorded in a matrix. Next, replaced ordinary rock flour (0-2 mm) with rock flour from a quarry of a previously known good stone material. With the remaining makadam (2-16 mm) the process are made all over again and the results are analyzed and compared. An asphalt with rock flour from quarry Supartallen and the remaining makadam from quarry Stöningsberget shows improved results compared with fraction 0-16 mm from quarry Stöningsberget and further tests in laboratory are made with this mixture. These quarries are geographically fairly close to each other, 250 km (about 150 miles), which motivates to choose these quarries for a full scale-test in the future. From these mixtures asphalt-bodies are manufactured by gasket with gyratory compactor and stiffness module is examined. In the economic and environmental profit attempts are made with a residue from the steel industry. An attempt carried out with the slag from ladles (0-2 mm). The slag is mixed with stone material from quarry Supartallen where workability, breaking process and coverage is investigated. This is an initial attempt to introduce how the asphalt mixture behaves mixed with the slag. An evaluation was made with matrix where each asphalt mixture included. The asphalt mixture is graded according to machinability, coverage and breaking control. The bowl was analyzed and conclusions about the break could be drawn. Analyzes of the curing process and coverage was made by dismemberment of the mass. The results indicate that the rock flour has a significant role in coverage, extraction at mixing and mining process, however, the stiffness module has the same results in all mixtures. The mere stone flour shouldn’t be the problem but still has a significant role. At the aggregate of Supartallen is so good for the consideration and use of stone materials with similar properties and not rock material with a high amount of SiO2 as it provides poor coverage. The mass harden too quickly may depend on the content of binder, further laboratory work should be done with the binder content in focus.
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Liaudat, Joaquín. "Experimental and numerical study of the effect of stress on ASR expansions in concrete." Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/620624.
Full textAbstract:
This thesis aims at deepening in the understanding of the mechanisms by which the stress state affects the development of concrete expansions and cracking due to the Alkali-Silica Reaction (ASR). With this purpose, a combined experimental-numerical study has been undertaken. For the experimental part of the study, two new experimental setups have been developed and used in an extensive experimental campaign.
The first setup has made it possible to measure, seemingly for the first time, ASR expansion curves at the level of a single interface between a reactive aggregate and a cementitious matrix (mortar or cement paste), as well as to study the formed ASR products by means of SEM images and EDS analyses. The thesis includes results from various series of Interfacial Expansion Tests under different conditions, in order to assess their influence on the kinetics of the measured expansions.
For the second experimental setup, an existing triaxial testing machine has been adapted. With this machine, experimental ASR expansion curves from cubical concrete specimens subjected to three different triaxial stress states have been obtained. The results seem to indicate that the volumetric ASR expansion rate is reduced as the applied volumetric compressive stress is increased. Additionally, there seems to be an increase in the expansion rate in the less compressed direction in detriment of the expansion rates in the most compressed ones.
Based on the results obtained in the experimental study, as well as on published results from other authors, a reaction-expansion mechanism has been proposed that may explain the effects of the stress state on the ASR expansions of concrete. This reaction-expansion mechanism has been theoretically formulated and implemented in a coupled Chemo-Mechanical Finite Element (FE) model. In this model, the chemical and the mechanical problems are solved by means of two different FE codes, coupled via a staggered implementation. Both codes are used to analyse the same FE mesh in which the reactive aggregates are explicitly represented, embedded in a matrix phase representing non-reactive mortar or cement paste.
This mesh includes zero-thickness interface elements which are inserted a priori along all the aggregate-matrix contacts and also along some predefined matrix-matrix and aggregate-aggregate inter-elements boundaries in order to represent the main potential crack paths. In the case of the aggregate-matrix contacts, the interface elements also make it possible to represent the specific properties of the Interfacial Transition Zones.
The chemical formulation consists of three primary diffusion/reaction fields for aqueous silicate, calcium and alkalis in the pore solution, complemented by a number of chemical kinetics and chemical equilibrium equations. The dissolution/precipitation reactions involved in ASR expansions are considered to occur only within the zero-thickness interface elements representing fractures and aggregate-matrix contacts, while diffusion of primary species may occur within interface as well as continuum finite elements. The volume fraction distribution of the solid chemical species (reactive silica, portlandite, and ASR products) associated to the interface elements evolve with the progress of the reactions.
From a mechanical point of view, the interface elements are equipped with an elasto-plastic constitutive model based on concepts and parameters of non-linear fracture mechanics. In contrast, the continuum elements are assumed to behave linear elastically. Thus, the mechanical non-linearity of the overall model is due exclusively to the zero-thickness interface elements.
The model has been used for simulating a number of ideal and real cases, demonstrating its ability to reproduce experimental observations regarding the effects of concrete stress state on the development of the ASR expansions.<br>Esta tesis tiene como objetivo principal profundizar en la comprensión de los mecanismos por los cuales el estado tensional del hormigón afecta el desarrollo de las expansiones y fisuras debido a la Reacción de Álcali-Sílice (RAS). Con este propósito, se ha realizado un estudio combinado numérico-experimental del fenómeno. Para la parte experimental del estudio, se han desarrollado dos nuevas configuraciones experimentales, que posteriormente han sido utilizadas en una extensa campaña experimental. La primera configuración ha permitido medir, aparentemente por primera vez, curvas de expansión por RAS a nivel de una única interfaz entre un árido reactivo y una matriz cementosa (pasta de cemento o mortero), así como estudiar los productos formados por la RAS mediante imágenes SEM y análisis EDS. Para la segunda configuración experimental, se ha adaptado una máquina existente para ensayos triaxiales. Con esta máquina, se han obtenido curvas experimentales de expansión por RAS de probetas cúbicas de hormigón sometidas a tres estados distintos de tensión triaxial. Los resultados obtenidos parecen indicar que la tasa volumétrica de expansión por RAS es reducida a medida que se aumenta la tensión volumétrica de compresión aplicada. Además, parece haber un aumento en la tasa de expansión en la dirección menos comprimida en detrimento de las tasas de expansión en las direcciones más comprimidas. Con base en los resultados obtenidos en el estudio experimental, así como en los resultados publicados por otros autores, se ha propuesto un mecanismo de reacción-expansión que podría explicar los efectos del estado tensional en las expansiones por RAS del hormigón. Este mecanismo de reacción-expansión se ha formulado teóricamente e implementado en un modelo acoplado Quemo-Mecánico de Elementos Finitos (EF). En este modelo, los problemas químico y mecánico se resuelven mediante dos códigos de EF diferentes, acoplados mediante una implementación escalonada. Ambos códigos usan la misma malla de EF en la que los áridos reactivos se representan explícitamente rodeados de una matriz cementosa no reactiva. Esta malla incluye elementos junta sin espesor que se insertan a priori a lo largo de todos los contactos matriz-árido y también a lo largo de algunos contactos predefinidos matriz-matriz y árido-árido para representar los principales caminos potenciales de fractura. En el caso de los contactos de matriz-árido, los elementos junta también permiten representar las propiedades específicas de las Zonas de Transición. La formulación del problema químico consiste en tres campos de difusión / reacción primarios correspondientes a silicato, calcio y álcalis en la solución de poros, complementados por una serie de ecuaciones de cinética química y equilibrio químico. Las reacciones de disolución / precipitación involucradas en las expansiones por RAS pueden ocurrir únicamente en los elementos junta que representan fracturas y contactos árido-matriz, mientras que la difusión de las especies primarias puede ocurrir tanto en elementos junta como continuos. La distribución de las fracciones volumétricas de las especies sólidas (sílice reactiva, portlandita y productos de las RAS) asociadas a los elementos junta evoluciona con el progreso de las reacciones. Desde un punto de vista mecánico, los elementos junta están equipados con un modelo constitutivo elasto-plástico basado en conceptos y parámetros de la teoría no lineal de la mecánica de fractura. Por el contrario, los elementos del continuo se asumen linealmente elásticos. En consecuencia, la no linealidad mecánica del modelo se logra exclusivamente por medio de los elementos junta. El modelo se ha utilizado para simular una serie de casos ideales y reales, en los que ha demostrado su capacidad para reproducir observaciones experimentales con respecto a los efectos del estado tensional del hormigón en el desarrollo
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Di, Nardo Andrea. "I veicoli a fine vita: il recupero energetico del materiale proveniente dalla frantumazione (ASR)." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amslaurea.unibo.it/2918/.
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Alatwi, Aadel. "Perceptually-Motivated Speech Parameters for Efficient Coding and Noise-Robust Cepstral-Based ASR Features." Thesis, Griffith University, 2018. http://hdl.handle.net/10072/380065.
Full textAbstract:
With speech being a natural form of human communication in everyday life, speech
processing technologies are gradually being incorporated into modern devices and
many applications such as Automatic Speech Recognition (ASR). Efficient ASR im-
plementations are key for technologies which simplify service accessibility for clients
such as automatic translation and dictation software. ASR task is known as a
client/server model. Various modes have been proposed for this approach includ-
ing Network Speech Recognition (NSR) and Distributed Speech Recognition (DSR).
In NSR, feature extraction and recognition task are performed at the server-side.
The advantage of NSR is that no changes are required for the existing mobile tele-
phony equipment and networks. Conversely, the ASR features are extracted from
the speech signal at the client-side in DSR. Unlike the Linear Predictive Coding
(LPC) parameters used in NSR, which are known to be more sensitive to the effects
of undesirable noise, DSR features can exploit human auditory effects which signi -
cantly aid in speech recognition. The downside of DSR, however, is the requirement
of a dedicated channel for the transmission process.
This thesis presents novel signal processing algorithms that extract perceptually-
motivated LPC parameters for computation at the client-side { which provide good
quality speech coding { and enable noise-robust ASR features at the server-side.
These algorithms are demonstrated through three studies.
The rst study introduces a proposed method for estimating perceptually-
motivated LPC parameters { the Smoothed and Thresholded Power Spectrum Lin-
ear Prediction (STPS-LP) analysis. The algorithm is based on the property of simultaneous masking found in the human auditory system to estimate noise-robust LPC
parameters. The proposed method is evaluated and compared to three other LP
analysis methods: the conventional Autocorrelation Method (AM-LP), the Spec-
tral Envelope Estimation Vocoder method (SEEVOC-LP), and the LP Spectrum
Modi cation method (LPSM-LP). Comparisons of the robustness and quality of
speech demonstrated that the proposed STPS-LP method outperforms the three
other schemes.
The second study investigates the quantisation performance of various LPC pa-
rameters using different quantiser schemes. The proposed STPS-LP method pro-
duced less quantisation distortion than the aforementioned methods.
The third study builds on the proposed coefficients from the rst study, proposing
a conversion algorithm for obtaining a set of noise-robust ASR features to be used
at the server-side. These cepstral-based features are called the STPS-LP Cepstral
Coefficients (STPS-LPCCs). The recognition performance using the STPS-LPCCs
is improved in comparison to that using the AM-LP, SEEVOC-LP, and LPSM-LP
cepstral coefficients, under clean and noisy conditions in the baseline, matched, and
mismatched models.
This research proposal provides two main advantages over the conventional NSR
and DSR schemes: (i) the perceptually-motivated LPC parameters are used for
speech coding, and (ii) no dedicated communications channel is required since the
existing LPC bitstream in speech coders is used for transmitting the features. These
bene ts make the proposed method greatly applicable to current mobile telephony
networks and should improve the user experience when interacting with ASR ser-
vices.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Eng & Built Env<br>Science, Environment, Engineering and Technology<br>Full Text
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Li, Zihui. "Acid Leaching Resistance and Alkali Silica Reaction (ASR) of Alkali-Activated Cement Free Binders." Thesis, Clarkson University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10640300.
Full textAbstract:
<p> Recently, increased awareness of the significance of developing sustainable materials for construction has renewed the interest in exploring Alkali activated concrete (AAC), a concrete that contains no cement, but only industrial by-products such as fly ash and slag, as a low energy alternative to the conventional concrete. Although the feasibility of making alkali–activated concrete with acceptable strength and mechanical properties is well documented, the information regarding the long-term durability, including resistance to acid attack and alkali silica reaction (ASR), is far from comprehensive and there is a need to increase the understanding of these durability issues. In this dissertation, these durability issues are addressed, and improvements in this novel technology will increase acceptance in industry. This dissertation presents a comprehensive evaluation into the acid leaching resistance of Alkali-Activated Concrete (AAC) and Ordinary Portland Cement (OPC). The deterioration in AAC and OPC when exposed to different types of acid laden (organic and inorganic) environments are quantified by characterizing the strength degradation, mass change and visual appearances. The changes in microstructure development and chemical composition are examined and analyzed in order to determine the mechanism of deterioration. Additionally, the effect of the addition of nanoparticles on the mechanical properties and resistance to sulfuric leaching of Alkali Activated Slag concrete (AAS) are also explored in this study. </p><p> Furthermore, this dissertation summarizes the findings of an experimental evaluation of alkali silica reaction (ASR) in cement free alkali activated concrete (AAC). The susceptibility of AAC to deleterious ASR was evaluated in this study in accordance with relevant ASTM standards. This study also compares the resistance of AAC with ordinary portland cement concrete (OPC) while exposed to ASR under ASTM C 1293 and ASTM C1567 tests. In particular, the focus of this investigation is to assess the effectiveness of existing ASTM test methods in identifying the occurrence of ASR in alkali activated slag cement (AAS) concrete. In addition to that, influences of activator parameters including the effect of binder type, activator concentration, activator type and water content to the resistance of ASR in AAC were also evaluated. Finally, a scanning electron microscopic study coupled with EDX analyses was used to explain the mechanism of ASR occurrence in AAC and OPC.</p><p>
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Trottier, Cassandra. "Evaluation of Alkali-Silica Reaction (ASR)-Induced Damage Generation and Prolongation in Affected Recycle Concrete." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41093.
Full textAbstract:
Recycled concrete is among the rising eco-friendly construction materials which helps to reduce waste and the need for new natural resources. However, such concrete may present previous deterioration due to, for instance, alkali-silica reaction (ASR), which is an ongoing distress mechanism that may keep being developed in the recycled material. This work aims to evaluate the potential of further distress and crack development (i.e. initiation and propagation) of AAR-affected RCA concrete in recycled mixtures displaying distinct past damage degrees and reactive aggregate types. Therefore, concrete specimens incorporating two highly reactive aggregates (Springhill coarse aggregate and Texas sand) were manufactured in the laboratory and stored in conditions enabling ASR development. The specimens were continuously monitored over time and once they reached marginal (0.05%) and very high (0.30%) expansion levels, they were crushed into RCA particles and re-used to fabricate RCA concrete. The RCA specimens were then placed in the same previous conditions and the “secondary” ASR-induced development monitored over time. Results show that the overall damage in ASR-affected RCA concrete is quite different from affected conventional concrete, especially with regards to the severely damaged RCA particles, where ASR is induced by a reactive coarse aggregate, as the RCA particle itself may present several levels of damage simultaneously caused by past/ongoing ASR and newly formed ASR. Moreover, the influence of the original damage extent in such RCA concrete was captured by the slightly damaged RCA mixture eventually reaching the same damage level as the severely damaged mixture. Furthermore, the original extent of deterioration influence the “secondary” induced expansion and damage of RCA concrete since the higher the original damage level, the higher the cracks numbers and lengths observed in the RCA concrete for the same expansion level whereas wider cracks are generated by RCA having previously been subjected to slight damage thus indicating the difference in the distress mechanism as a function of original extent of damage. In addition, it has been found that distress on RCA containing a reactive sand generates and propagates from the residual mortar (RM) into the new mortar (NM) as opposed to RCA containing a reactive coarse aggregate, being generated and propagated from the original coarse aggregate (i.e. original virgin aggregate – OVA) into the NM. Likewise, RCA containing a reactive sand caused longer and higher number of cracks for the same “secondary” induced expansion than the RCA made of reactive coarse aggregate. Finally, novel qualitative and descriptive models are proposed in this research to explain ASR-induced distress generation and propagation on RCA mixtures made of reactive fine and coarse aggregates.
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Wuth, Sepúlveda Jorge. "Desarrollo de Aplicación de Reconocimiento de Voz para Telefonía Celular." Tesis, Universidad de Chile, 2007. http://www.repositorio.uchile.cl/handle/2250/104639.
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Paudel, Shree Raj. "Pore Structure and Pore Solution in Alkali Activated Fly Ash Geopolymer Concrete and Its Effect on ASR of Aggregates with Wide Silicate Contents." Thesis, North Dakota State University, 2019. https://hdl.handle.net/10365/31687.
Full textAbstract:
Alkali silica reaction (ASR) is detrimental to concrete. It is a time-dependent phenomenon, which can lead to strength loss, cracking, volume expansion, and premature failure of concrete structures. In essence, it is a particular chemical reaction involving alkali hydroxides and reactive form of silica present within the concrete mix. Geopolymer is a type of alkaline activated binder synthesized through polycondensation reaction of geopolymeric precursor and alkali polysilicates. In this thesis, three types of reactive aggregates with different chemical compositions were used. Systematic laboratory experiments and microstructural analysis were carried out for the geopolymer concrete and the OPC concrete made with the same aggregates. The result suggests that the extent of ASR reaction due to the presence of three reactive aggregates in geopolymer concrete is substantially lower than that in OPC based concrete, which is explained by the pore solution change and verified through their microstructural variations and FTIR images.
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Loweimi, Erfan. "Robust phase-based speech signal processing from source-filter separation to model-based robust ASR." Thesis, University of Sheffield, 2018. http://etheses.whiterose.ac.uk/19409/.
Full textAbstract:
The Fourier analysis plays a key role in speech signal processing. As a complex quantity, it can be expressed in the polar form using the magnitude and phase spectra. The magnitude spectrum is widely used in almost every corner of speech processing. However, the phase spectrum is not an obviously appealing start point for processing the speech signal. In contrast to the magnitude spectrum whose fine and coarse structures have a clear relation to speech perception, the phase spectrum is difficult to interpret and manipulate. In fact, there is not a meaningful trend or extrema which may facilitate the modelling process. Nonetheless, the speech phase spectrum has recently gained renewed attention. An expanding body of work is showing that it can be usefully employed in a multitude of speech processing applications. Now that the potential for the phase-based speech processing has been established, there is a need for a fundamental model to help understand the way in which phase encodes speech information. In this thesis a novel phase-domain source-filter model is proposed that allows for deconvolution of the speech vocal tract (filter) and excitation (source) components through phase processing. This model utilises the Hilbert transform, shows how the excitation and vocal tract elements mix in the phase domain and provides a framework for efficiently segregating the source and filter components through phase manipulation. To investigate the efficacy of the suggested approach, a set of features is extracted from the phase filter part for automatic speech recognition (ASR) and the source part of the phase is utilised for fundamental frequency estimation. Accuracy and robustness in both cases are illustrated and discussed. In addition, the proposed approach is improved by replacing the log with the generalised logarithmic function in the Hilbert transform and also by computing the group delay via regression filter. Furthermore, statistical distribution of the phase spectrum and its representations along the feature extraction pipeline are studied. It is illustrated that the phase spectrum has a bell-shaped distribution. Some statistical normalisation methods such as mean-variance normalisation, Laplacianisation, Gaussianisation and Histogram equalisation are successfully applied to the phase-based features and lead to a significant robustness improvement. The robustness gain achieved through using statistical normalisation and generalised logarithmic function encouraged the use of more advanced model-based statistical techniques such as vector Taylor Series (VTS). VTS in its original formulation assumes usage of the log function for compression. In order to simultaneously take advantage of the VTS and generalised logarithmic function, a new formulation is first developed to merge both into a unified framework called generalised VTS (gVTS). Also in order to leverage the gVTS framework, a novel channel noise estimation method is developed. The extensions of the gVTS framework and the proposed channel estimation to the group delay domain are then explored. The problems it presents are analysed and discussed, some solutions are proposed and finally the corresponding formulae are derived. Moreover, the effect of additive noise and channel distortion in the phase and group delay domains are scrutinised and the results are utilised in deriving the gVTS equations. Experimental results in the Aurora-4 ASR task in an HMM/GMM set up along with a DNN-based bottleneck system in the clean and multi-style training modes confirmed the efficacy of the proposed approach in dealing with both additive and channel noise.
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Menoret, Antoine. "Influence des protecteurs aux stress cellulaires sur l'immunogénicité des cellules tumorales." Nantes, 1994. http://www.theses.fr/1994NANT06VS.
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Wilson, Aaron Benjamin. "Enhancement of Polar WRF atmospheric and surface processes: An annual simulation." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1268066611.
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Rey, Martínez Lorena. "Formación de contaminantes y estudio cinético de la descomposición térmica de dos combustibles alternativos: CDR y ASR." Doctoral thesis, Universidad de Alicante, 2016. http://hdl.handle.net/10045/59165.
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Jones, Gregg William. "Investigation of the Mechanisms for Mobilization of Arsenic in Two ASR Systems in Southwest Central Florida." Thesis, University of South Florida, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3741476.
Full textAbstract:
<p> Aquifer storage and recovery (ASR) is a strategy in which water is injected into an aquifer when it is plentiful and pumped from the aquifer when water is scarce. An impediment to ASR in Florida is leaching of naturally-occurring arsenic from limestone of the Upper Floridan Aquifer System (UFAS) into stored water. The concentration of arsenic in surface water, which serves as the recharge water for many ASR systems, and native groundwater is usually much less than 3.0 µ/L. However, data from ASR wells in Florida show that arsenic in recovered water frequently exceeded the 10 µg/L maximum contaminant level (MCL) established by the Environmental Protection Agency and were as high as 130.0 µg/L. The cause of elevated arsenic concentrations is displacement of reduced native groundwater with oxygenated surface water that dissolves arsenic-bearing pyrite in limestone. Although arsenic can be removed from recovered water during final treatment, mobilization of arsenic in the aquifer at levels that exceed the MCL is problematic under federal regulations. </p><p> This dissertation investigated a number of aspects of the ASR/arsenic problem to provide additional insights into the mechanisms of arsenic mobilization and measures that could be taken to avoid or reduce the release of arsenic during ASR operations.</p><p> Chapter 2, involved development of a geochemical model to simulate an ASR system’s injection of oxygenated surface water into reduced groundwater to determine whether aquifer redox conditions could be altered to the degree of pyrite instability. Increasing amounts of injection water were added to the storage-zone in a series of steps and resulting reaction paths were plotted on pyrite stability diagrams. Unmixed storage-zone water in wells plotted within the pyrite stability field indicating that redox conditions were sufficiently reducing to allow for pyrite stability. Thus arsenic is immobilized in pyrite and its concentration in groundwater should be low. During simulation, as the injection/storage-zone water ratio increased, redox conditions became less reducing and pyrite became unstable. The result would be release of arsenic from limestone into storage-zone water.</p><p> Chapter 3 examined the importance of maintaining a substantial volume of stored water around an ASR well to prevent recovery of reduced native groundwater to the vicinity of the well. Depleting the stored water and recovering reduced native groundwater would result in dissolution of arsenic-bearing hydrous ferric oxide (HFO) and release of arsenic into water recovered from the ASR well. Injection/recovery volumes for each cycle for each well were tracked to determine if a substantial volume of stored water was maintained for each cycle or if it was depleted so that reduced native groundwater was brought back to the well. Each well was assigned to either the “storage zone maintained group” where a zone of stored water was established in early cycles and largely maintained through the period of investigation, or the “storage-zone depleted group” where a zone of stored water was either established in later cycles and/or was depleted during the period of investigation. Graphical and statistical analyses verified that maximum arsenic concentrations for storage-zone maintained wells were nearly always lower in each cycle and declined below the MCL after fewer cycles than those of storage-zone depleted wells.</p><p> Chapter 4 was a mineralogical investigation of cores located at 20 m (ASR core 1), 152 m (ASR core 2), and 452 m (ASR core 3) from operating ASR wells to determine where mobilized arsenic in limestone is precipitated during ASR. If arsenic is precipitated distally, reduced concentrations of elements in pyrite, (iron, sulfur, arsenic, etc.) would be expected in ASR core 1 relative to more distant cores and there would be noticeable changes in appearance of pyrite crystals due to enhanced oxidation. The results showed that mean concentrations of the elements were lowest in ASR core 2, which did not support distal precipitation. However, scanning electron microscopy identified well-defined pyrite framboids only in core 3 while framboids in ASR cores 1 and 2 were less clear and distinct, indicating pyrite oxidation in cores closest to ASR wells.</p><p> Statistical comparison of concentrations of iron, sulfur, and arsenic between the three ASR cores and 19 control cores not subject to ASR, showed that mean concentrations in ASR cores 1 and 2 were statistically similar to concentrations in control cores. This indicated that concentrations in ASR cores 1 and 2 had not been significantly reduced by ASR. The concentrations of elements were higher in ASR core 3 than in ASR cores 1 and 2 and control cores and statistically dissimilar to all but one control core. This indicated natural heterogeneity in core 3 rather than diminution of elements in ASR cores 1 and 2 due to ASR. The statistical analysis supported local precipitation. Once arsenic is mobilized from dissolved pyrite, it is rapidly complexed with precipitated HFO near the well. As long as all of the stored water is not removed during recovery so that reduced native groundwater is brought back to the well, HFO remains stable and complexed with arsenic. The concentration of elements would not have been lowest in ASR core 1 for this reason and because calculations showed that the mass of arsenic removed during recovery events prior to coring was minor compared to the total in limestone surrounding the well. The implications of this are that while large quantities of arsenic are present near the ASR well, only a small percentage may be available for dissolution. Most arsenic occurs with pyrite in limestone, which may insulate it from exposure to oxidized injection water. Water recovered from ASR wells may continue to have low concentrations of arsenic indefinitely because as limestone is dissolved, more pyrite becomes exposed and available for dissolution. </p><p> The primary contribution of this dissertation to understanding and overcoming the arsenic problem in ASR systems is the empirical data developed to support or challenge important ASR/arsenic hypotheses. These data were used to 1) establish that background concentrations of arsenic in groundwater of the Suwannee Limestone were less than 1µg/L, 2) demonstrate that redox conditions necessary for pyrite in limestone to become unstable and dissolve occur when oxygenated surface water is injected into the aquifer, 3) demonstrate that the concentration of pyrite in the Suwannee Limestone is spatially variable to a high degree, 4) support the hypothesis that following injection of oxygenated surface water, pyrite in limestone dissolves and releases arsenic into solution and HFO forms and complexes with the arsenic near the ASR well, 5) propose that only a small percentage of pyrite near an ASR well may be available for dissolution during each cycle because most occurs in the limestone matrix and is isolated from injection water, 6) propose that as a result of the previous conclusion, water recovered from ASR systems may continue to have low concentrations of arsenic indefinitely because as limestone that contains pyrite is dissolved with each cycle, additional pyrite is exposed and is available for dissolution, and 7) support the effectiveness of maintaining a zone of stored water in an ASR well as an effective means of minimizing arsenic in recovered water during ASR.</p>
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Bezerra, Agnes. "The Use of Artificial Intelligence for Assessing Damage in Concrete Affected by Alkali-Silica Reaction (ASR)." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42730.
Full textAbstract:
Over the last decades, numerous techniques have been proposed worldwide to assess the actual damage of critical concrete infrastructure. A method that has progressively been used in North America is a novel microscopic tool, the Damage Rating Index (DRI). This semi-quantitative petrographic tool was developed to reliably appraise both the nature and degree of damage in concrete affected by alkali-silica reaction (ASR), which may threaten the serviceability and the durability of concrete infrastructure around the world. Performing the DRI consists of counting numerous distress features (i.e. closed and open cracks in the aggregate and cement paste) encountered on the surface of polished concrete sections (lab-made specimens or cores extracted from field structures) using a stereomicroscope at 16x magnification; once recognized and counted, the distinct distress features are multiplied by weighting factors whose purpose is to balance their relative importance towards the distress mechanism under consideration (e.g., ASR). Although reliable and efficient, performing the DRI is exceptionally time-consuming, and its results are highly operator sensitive, requiring an experienced petrographer. Therefore, this study proposes using artificial intelligence (AI) through machine learning (ML) techniques to automate the DRI test protocol estimating the damage degree of concrete affected by ASR. The ML subfield known as Deep Learning (DL) was implemented to create human-like intelligence connections using a Convolutional Neural Network (CNN) algorithm, which can predict the DRI results (machine assessment) that are close to those expected (human assessment. This research is divided into two phases: 1) performing cracks recognition using sliding windows and 2) an advanced pixel recognition. In the first phase, the results displayed some inconsistencies in cracks classification; yet, for cracks identification in the cement paste, in particular, this method presented promising results. However, the advanced pixel recognition improved the drawbacks of the first phase, providing a more accurate cracks recognition and classification. The DRI number estimation was subsequently implemented into the CNN model achieving a 74.4% accuracy. Hence, the DRI automation is a revolutionary step towards a more ubiquitous use of the method since less time is required to perform the task, besides avoiding variability among petrographers and enabling non/less experienced professionals to take advantage of this powerful microscopic tool. With a more widely accessible diagnostic tool, ASR-affected critical concrete infrastructure could be more efficiently assessed, which would ultimately increase their safety.
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Torabi, Asr Fatemeh [Verfasser], and Vera [Akademischer Betreuer] Demberg. "An Information theoretic approach to production and comprehension of ciscourse markers / Fatemeh Torabi Asr. Betreuer: Vera Demberg." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2015. http://d-nb.info/1079840206/34.
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Schünemann, Mariana. "Identificação de fatores reguladores da expressão de genes ASR(ABA, Stress and Ripening) de arroz (Oryza sativa)." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/117918.
Full textAbstract:
Os estresses abióticos impostos à planta no campo, tais como o estresse salino, toxidez por alumínio, frio, seca, entre outros, afetam seu crescimento, desenvolvimento e produtividade. Dentre as gramíneas cultivadas, o arroz (Oryza sativa) é uma das culturas de maior importância no Brasil, cuja oscilação na produção acarreta prejuízos consideráveis à economia brasileira. Dessa forma, o estudo das interações entre os estresses abióticos e as respostas dos vegetais frente a esses estímulos ambientais é fundamental para um conhecimento detalhado desses mecanismos. O arroz é um dos cereais mais tolerantes ao alumínio (Al), sendo um ótimo modelo para o estudo de mecanismos de tolerância. Neste trabalho, foi estudado o papel das proteínas ASR na tolerância ao Al. A expressão dos genes ASR (ABA, Stress and Ripening) é induzida por ABA, estresses e amadurecimento do fruto. Essas proteínas foram caracterizadas como chaperonas e fatores de transcrição. Os genes da família OsASR também têm o nível de transcritos aumentado em resposta ao Al, sendo OsASR1 e OsASR5 os genes com expressão mais abundante em arroz. No entanto, as regiões promotoras responsivas ao Al e os fatores de transcrição reguladores da expressão desses genes ainda não foram descritos. Assim, este trabalho tem como objetivo geral a identificação dos fatores que regulam a transcrição dos genes OsASR1 e OsASR5. Para tanto, construções contendo fragmentos dos promotores desses genes dirigindo a expressão do gene repórter GUS foram obtidas, visando ensaio de expressão transiente em protoplastos de arroz submetidos ao tratamento com Al. Os fragmentos das regiões promotoras de ambos os genes OsASR1 e OsASR5 foram todos responsivos ao Al. Também foi realizado ensaio de transativação em protoplastos de Arabidopsis thaliana para verificar a existência de auto-regulação nesses genes. Tanto ASR1 quanto ASR5 foram capazes de transativar seus próprios promotores. Além disso, foi realizada uma triagem de biblioteca de cDNAs por mono-híbrido em levedura com fragmento da região promotora de OsASR5. Com essa abordagem, foram identificados sete genes candidatos a codificadores de fatores capazes de interação DNA-proteína.<br>The abiotic stress that plants in the field are subjected to, such as salt, aluminum, cold, drought, among others, affect their growth, development and productivity. Among cultivated grasses, rice (Oryza sativa) is one of the most important crops in Brazil, whose oscillation in production causes considerable costs to the Brazilian economy. Thus, the study of interactions between abiotic stresses and plant responses to these environmental stimuli is essential to a detailed knowledge of these mechanisms. Rice is one of the most Al-tolerant crops, being a great model for studying Al-tolerance mechanisms. In this work, the role of ASR proteins in Al tolerance was studied. The expression of ASR (ABA, Stress and Ripening) genes is induced by ABA, stresses and fruit ripening. These proteins were characterized as chaperones and transcription factors. The OsASR genes also have increased transcript accumulation in response to Al, and OsASR1 and OsASR5 have the most abundant expression in rice. However, the Al-responsive promoter regions and the transcription factors that regulate these genes have not yet been described. Therefore, the goal of this work is to identify regulating factors of OsASR1 and OsASR5 gene transcription. For this, vectors containing promoter fragments of these genes driving the expression of the GUS gene were constructed and transient expression assays were performed in rice protoplasts subjected to Al treatment. All of the promoter fragments were Al-responsive for both OsASR1 and OsASR5 genes. Transactivation assays in Arabidopsis thaliana protoplasts were also conducted in order to verify the existence of auto-regulation in these genes. Both ASR1 and ASR5 were able to transactivate its own promoters. Furthermore, a library screening was performed by yeast one-hybrid using a promoter fragment from OsASR5. With this approach, seven candidate genes encoding transcription factors capable of DNA-protein interactions were identified.
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Mossberg, Zimon. "Achieving Automatic Speech Recognition for Swedish using the Kaldi toolkit." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-194178.
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The meager offering of online commercial Swedish Automatic Speech Recognition ser-vices prompts the effort to develop a speech recognizer for Swedish using the open sourcetoolkit Kaldi and publicly available NST speech corpus. Using a previous Kaldi recipeseveral GMM-HMM models are trained and evaluated against commercial options toallow for reasoning of the performance of a customized solution for Automatic SpeechRecognition to that of commercial services. The evaluation takes both accuracy andcomputational speed into consideration. Initial results of the evaluation indicate a sys-tematic bias in the selected test set confirmed by a follow up investigative evaluation.The conclusion is that building a speech recognizer for Swedish using the NST corpusand Kaldi without expert knowledge is feasible but requires further work.<br>En taligenkännare för svenska utvecklas med målet att utvärdera hur en taligenkännareutvecklad med fritt tillgängliga verktyg står sig mot kommersiella taligenkänningstjänster.Verktyget som används är det öppna källkodsverktyget Kaldi och som träningsdataanvänds det offentligt tillgängliga talkorpuset för svenska från NST. De framtagna mod-ellerna jämförs mot kommersielt tillgängliga tjänster för taligenkänning på svenska.Tidiga resultat i jämförelsen indikerar ett systemiskt jäv i den valda testdata, vilketbekräftas av en uppföljande undersökande utvärdering. Slutsatsen av arbetet är attutsikterna att ta fram en taligenkännare för svenska är goda men kräver omfattandearbete.
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江良, 和徳. "リチウムイオン内部圧入によるASR抑制効果に関する研究". 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120831.
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Kraal, Ben James, and n/a. "Considering design for automatic speech recognition in use." University of Canberra. Information Sciences and Engineering, 2006. http://erl.canberra.edu.au./public/adt-AUC20070514.092924.
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Talking to a computer is hard. Large vocabulary automatic speech recognition
(ASR) systems are difficult to use and yet they are used by many
people in their daily work. This thesis addresses the question: How is
ASR used and made usable and useful in the workplace now?
To answer these questions I went into two workplaces where ASR is
currently used and one where ASR could be used in the future. This field
work was done with designing in mind. ASR dictation systems are currently
used in the Australian Public Service (APS) by people who suffer
chronic workplace overuse injuries and in the Hansard department of Parliament
House (Hansard) by un-injured people.
Analysing the experiences of the users in the APS and at Hansard
showed that using an ASR system in the workplace follows a broad trajectory
that ends in the continued effort to maintain its usefulness. The
usefulness of the ASR systems is �performed into existence� by the users
with varying degrees of success. For both the APS and Hansard users,
they use ASR to allow work to be performed; ASR acts to bridge the gap
between otherwise incompatible ways of working.
This thesis also asks: How could ASR be used and made usable and
useful in workplaces in the future? To answer this question, I observed
the work of communicating sentences at the ACT Magistrates Court.
Communicating sentences is a process that is distributed in space and
time throughout the Court and embodied in a set of documents that have
a co-ordinating role. A design for an ASR system that supports the process
of communicating sentences while respecting existing work process
is described.
Moving from field work to design is problematic. This thesis performs
the process of moving from field work to design, as described above, and
reflects the use of various analytic methods used to distill insights from
field work data.
The contributions of this thesis are:
� The pragmatic use of existing social research methods and their antecedents
as a corpus of analyses to inspire new designs;
vi
� a demonstration of the use of Actor-Network Theory in design both
as critique and as part of a design process;
� empirical field-work evidence of how large vocabulary ASR is used
in the workplace;
� a design showing how ASR could be introduced to the rich, complicated,
environment of the ACT Magistrates Court; and,
� a performance of the process of moving from field work to design.
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Swietojanski, Paweł. "Learning representations for speech recognition using artificial neural networks." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/22835.
Full textAbstract:
Learning representations is a central challenge in machine learning. For speech recognition, we are interested in learning robust representations that are stable across different acoustic environments, recording equipment and irrelevant inter– and intra– speaker variabilities. This thesis is concerned with representation learning for acoustic model adaptation to speakers and environments, construction of acoustic models in low-resource settings, and learning representations from multiple acoustic channels. The investigations are primarily focused on the hybrid approach to acoustic modelling based on hidden Markov models and artificial neural networks (ANN). The first contribution concerns acoustic model adaptation. This comprises two new adaptation transforms operating in ANN parameters space. Both operate at the level of activation functions and treat a trained ANN acoustic model as a canonical set of fixed-basis functions, from which one can later derive variants tailored to the specific distribution present in adaptation data. The first technique, termed Learning Hidden Unit Contributions (LHUC), depends on learning distribution-dependent linear combination coefficients for hidden units. This technique is then extended to altering groups of hidden units with parametric and differentiable pooling operators. We found the proposed adaptation techniques pose many desirable properties: they are relatively low-dimensional, do not overfit and can work in both a supervised and an unsupervised manner. For LHUC we also present extensions to speaker adaptive training and environment factorisation. On average, depending on the characteristics of the test set, 5-25% relative word error rate (WERR) reductions are obtained in an unsupervised two-pass adaptation setting. The second contribution concerns building acoustic models in low-resource data scenarios. In particular, we are concerned with insufficient amounts of transcribed acoustic material for estimating acoustic models in the target language – thus assuming resources like lexicons or texts to estimate language models are available. First we proposed an ANN with a structured output layer which models both context–dependent and context–independent speech units, with the context-independent predictions used at runtime to aid the prediction of context-dependent states. We also propose to perform multi-task adaptation with a structured output layer. We obtain consistent WERR reductions up to 6.4% in low-resource speaker-independent acoustic modelling. Adapting those models in a multi-task manner with LHUC decreases WERRs by an additional 13.6%, compared to 12.7% for non multi-task LHUC. We then demonstrate that one can build better acoustic models with unsupervised multi– and cross– lingual initialisation and find that pre-training is a largely language-independent. Up to 14.4% WERR reductions are observed, depending on the amount of the available transcribed acoustic data in the target language. The third contribution concerns building acoustic models from multi-channel acoustic data. For this purpose we investigate various ways of integrating and learning multi-channel representations. In particular, we investigate channel concatenation and the applicability of convolutional layers for this purpose. We propose a multi-channel convolutional layer with cross-channel pooling, which can be seen as a data-driven non-parametric auditory attention mechanism. We find that for unconstrained microphone arrays, our approach is able to match the performance of the comparable models trained on beamform-enhanced signals.